linux-stable/drivers/perf/arm_pmuv3.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* ARMv8 PMUv3 Performance Events handling code.
*
* Copyright (C) 2012 ARM Limited
* Author: Will Deacon <will.deacon@arm.com>
*
* This code is based heavily on the ARMv7 perf event code.
*/
#include <asm/irq_regs.h>
#include <asm/perf_event.h>
#include <asm/virt.h>
#include <clocksource/arm_arch_timer.h>
#include <linux/acpi.h>
#include <linux/bitfield.h>
arm64: perf: Add cap_user_time aarch64 It is useful to get the running time of a thread. Doing so in an efficient manner can be important for performance of user applications. Avoiding system calls in `clock_gettime` when handling CLOCK_THREAD_CPUTIME_ID is important. Other clocks are handled in the VDSO, but CLOCK_THREAD_CPUTIME_ID falls back on the system call. CLOCK_THREAD_CPUTIME_ID is not handled in the VDSO since it would have costs associated with maintaining updated user space accessible time offsets. These offsets have to be updated everytime the a thread is scheduled/descheduled. However, for programs regularly checking the running time of a thread, this is a performance improvement. This patch takes a middle ground, and adds support for cap_user_time an optional feature of the perf_event API. This way costs are only incurred when the perf_event api is enabled. This is done the same way as it is in x86. Ultimately this allows calculating the thread running time in userspace on aarch64 as follows (adapted from perf_event_open manpage): u32 seq, time_mult, time_shift; u64 running, count, time_offset, quot, rem, delta; struct perf_event_mmap_page *pc; pc = buf; // buf is the perf event mmaped page as documented in the API. if (pc->cap_usr_time) { do { seq = pc->lock; barrier(); running = pc->time_running; count = readCNTVCT_EL0(); // Read ARM hardware clock. time_offset = pc->time_offset; time_mult = pc->time_mult; time_shift = pc->time_shift; barrier(); } while (pc->lock != seq); quot = (count >> time_shift); rem = count & (((u64)1 << time_shift) - 1); delta = time_offset + quot * time_mult + ((rem * time_mult) >> time_shift); running += delta; // running now has the current nanosecond level thread time. } Summary of changes in the patch: For aarch64 systems, make arch_perf_update_userpage update the timing information stored in the perf_event page. Requiring the following calculations: - Calculate the appropriate time_mult, and time_shift factors to convert ticks to nano seconds for the current clock frequency. - Adjust the mult and shift factors to avoid shift factors of 32 bits. (possibly unnecessary) - The time_offset userspace should apply when doing calculations: negative the current sched time (now), because time_running and time_enabled fields of the perf_event page have just been updated. Toggle bits to appropriate values: - Enable cap_user_time Signed-off-by: Michael O'Farrell <micpof@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-30 20:14:34 +00:00
#include <linux/clocksource.h>
#include <linux/of.h>
#include <linux/perf/arm_pmu.h>
#include <linux/perf/arm_pmuv3.h>
#include <linux/platform_device.h>
#include <linux/sched_clock.h>
#include <linux/smp.h>
arm64: enable perf events based hard lockup detector With the recent feature added to enable perf events to use pseudo NMIs as interrupts on platforms which support GICv3 or later, its now been possible to enable hard lockup detector (or NMI watchdog) on arm64 platforms. So enable corresponding support. One thing to note here is that normally lockup detector is initialized just after the early initcalls but PMU on arm64 comes up much later as device_initcall(). To cope with that, override arch_perf_nmi_is_available() to let the watchdog framework know PMU not ready, and inform the framework to re-initialize lockup detection once PMU has been initialized. [dianders@chromium.org: only HAVE_HARDLOCKUP_DETECTOR_PERF if the PMU config is enabled] Link: https://lkml.kernel.org/r/20230523073952.1.I60217a63acc35621e13f10be16c0cd7c363caf8c@changeid Link: https://lkml.kernel.org/r/20230519101840.v5.18.Ia44852044cdcb074f387e80df6b45e892965d4a1@changeid Co-developed-by: Sumit Garg <sumit.garg@linaro.org> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Co-developed-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Colin Cross <ccross@android.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guenter Roeck <groeck@chromium.org> Cc: Ian Rogers <irogers@google.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Tzung-Bi Shih <tzungbi@chromium.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-05-19 17:18:42 +00:00
#include <linux/nmi.h>
/* ARMv8 Cortex-A53 specific event types. */
#define ARMV8_A53_PERFCTR_PREF_LINEFILL 0xC2
/* ARMv8 Cavium ThunderX specific event types. */
#define ARMV8_THUNDER_PERFCTR_L1D_CACHE_MISS_ST 0xE9
#define ARMV8_THUNDER_PERFCTR_L1D_CACHE_PREF_ACCESS 0xEA
#define ARMV8_THUNDER_PERFCTR_L1D_CACHE_PREF_MISS 0xEB
#define ARMV8_THUNDER_PERFCTR_L1I_CACHE_PREF_ACCESS 0xEC
#define ARMV8_THUNDER_PERFCTR_L1I_CACHE_PREF_MISS 0xED
/*
* ARMv8 Architectural defined events, not all of these may
* be supported on any given implementation. Unsupported events will
* be disabled at run-time based on the PMCEID registers.
*/
static const unsigned armv8_pmuv3_perf_map[PERF_COUNT_HW_MAX] = {
PERF_MAP_ALL_UNSUPPORTED,
[PERF_COUNT_HW_CPU_CYCLES] = ARMV8_PMUV3_PERFCTR_CPU_CYCLES,
[PERF_COUNT_HW_INSTRUCTIONS] = ARMV8_PMUV3_PERFCTR_INST_RETIRED,
[PERF_COUNT_HW_CACHE_REFERENCES] = ARMV8_PMUV3_PERFCTR_L1D_CACHE,
[PERF_COUNT_HW_CACHE_MISSES] = ARMV8_PMUV3_PERFCTR_L1D_CACHE_REFILL,
[PERF_COUNT_HW_BRANCH_MISSES] = ARMV8_PMUV3_PERFCTR_BR_MIS_PRED,
[PERF_COUNT_HW_BUS_CYCLES] = ARMV8_PMUV3_PERFCTR_BUS_CYCLES,
[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = ARMV8_PMUV3_PERFCTR_STALL_FRONTEND,
[PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = ARMV8_PMUV3_PERFCTR_STALL_BACKEND,
};
static const unsigned armv8_pmuv3_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
PERF_CACHE_MAP_ALL_UNSUPPORTED,
[C(L1D)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_L1D_CACHE,
[C(L1D)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_L1D_CACHE_REFILL,
[C(L1I)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_L1I_CACHE,
[C(L1I)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_L1I_CACHE_REFILL,
[C(DTLB)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_L1D_TLB_REFILL,
[C(DTLB)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_L1D_TLB,
[C(ITLB)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_L1I_TLB_REFILL,
[C(ITLB)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_L1I_TLB,
[C(LL)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_LL_CACHE_MISS_RD,
[C(LL)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_LL_CACHE_RD,
[C(BPU)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_BR_PRED,
[C(BPU)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_BR_MIS_PRED,
};
static const unsigned armv8_a53_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
PERF_CACHE_MAP_ALL_UNSUPPORTED,
[C(L1D)][C(OP_PREFETCH)][C(RESULT_MISS)] = ARMV8_A53_PERFCTR_PREF_LINEFILL,
[C(NODE)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_RD,
[C(NODE)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_WR,
};
static const unsigned armv8_a57_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
PERF_CACHE_MAP_ALL_UNSUPPORTED,
[C(L1D)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_RD,
[C(L1D)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_REFILL_RD,
[C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_WR,
[C(L1D)][C(OP_WRITE)][C(RESULT_MISS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_REFILL_WR,
[C(DTLB)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_RD,
[C(DTLB)][C(OP_WRITE)][C(RESULT_MISS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_WR,
[C(NODE)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_RD,
[C(NODE)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_WR,
};
static const unsigned armv8_a73_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
PERF_CACHE_MAP_ALL_UNSUPPORTED,
[C(L1D)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_RD,
[C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_WR,
};
static const unsigned armv8_thunder_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
PERF_CACHE_MAP_ALL_UNSUPPORTED,
[C(L1D)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_RD,
[C(L1D)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_REFILL_RD,
[C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_WR,
[C(L1D)][C(OP_WRITE)][C(RESULT_MISS)] = ARMV8_THUNDER_PERFCTR_L1D_CACHE_MISS_ST,
[C(L1D)][C(OP_PREFETCH)][C(RESULT_ACCESS)] = ARMV8_THUNDER_PERFCTR_L1D_CACHE_PREF_ACCESS,
[C(L1D)][C(OP_PREFETCH)][C(RESULT_MISS)] = ARMV8_THUNDER_PERFCTR_L1D_CACHE_PREF_MISS,
[C(L1I)][C(OP_PREFETCH)][C(RESULT_ACCESS)] = ARMV8_THUNDER_PERFCTR_L1I_CACHE_PREF_ACCESS,
[C(L1I)][C(OP_PREFETCH)][C(RESULT_MISS)] = ARMV8_THUNDER_PERFCTR_L1I_CACHE_PREF_MISS,
[C(DTLB)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_RD,
[C(DTLB)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_RD,
[C(DTLB)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_WR,
[C(DTLB)][C(OP_WRITE)][C(RESULT_MISS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_WR,
};
static const unsigned armv8_vulcan_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
PERF_CACHE_MAP_ALL_UNSUPPORTED,
[C(L1D)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_RD,
[C(L1D)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_REFILL_RD,
[C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_WR,
[C(L1D)][C(OP_WRITE)][C(RESULT_MISS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_REFILL_WR,
[C(DTLB)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_RD,
[C(DTLB)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_WR,
[C(DTLB)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_RD,
[C(DTLB)][C(OP_WRITE)][C(RESULT_MISS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_WR,
[C(NODE)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_RD,
[C(NODE)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_WR,
};
static ssize_t
armv8pmu_events_sysfs_show(struct device *dev,
struct device_attribute *attr, char *page)
{
struct perf_pmu_events_attr *pmu_attr;
pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
return sprintf(page, "event=0x%04llx\n", pmu_attr->id);
}
#define ARMV8_EVENT_ATTR(name, config) \
PMU_EVENT_ATTR_ID(name, armv8pmu_events_sysfs_show, config)
static struct attribute *armv8_pmuv3_event_attrs[] = {
/*
* Don't expose the sw_incr event in /sys. It's not usable as writes to
* PMSWINC_EL0 will trap as PMUSERENR.{SW,EN}=={0,0} and event rotation
* means we don't have a fixed event<->counter relationship regardless.
*/
ARMV8_EVENT_ATTR(l1i_cache_refill, ARMV8_PMUV3_PERFCTR_L1I_CACHE_REFILL),
ARMV8_EVENT_ATTR(l1i_tlb_refill, ARMV8_PMUV3_PERFCTR_L1I_TLB_REFILL),
ARMV8_EVENT_ATTR(l1d_cache_refill, ARMV8_PMUV3_PERFCTR_L1D_CACHE_REFILL),
ARMV8_EVENT_ATTR(l1d_cache, ARMV8_PMUV3_PERFCTR_L1D_CACHE),
ARMV8_EVENT_ATTR(l1d_tlb_refill, ARMV8_PMUV3_PERFCTR_L1D_TLB_REFILL),
ARMV8_EVENT_ATTR(ld_retired, ARMV8_PMUV3_PERFCTR_LD_RETIRED),
ARMV8_EVENT_ATTR(st_retired, ARMV8_PMUV3_PERFCTR_ST_RETIRED),
ARMV8_EVENT_ATTR(inst_retired, ARMV8_PMUV3_PERFCTR_INST_RETIRED),
ARMV8_EVENT_ATTR(exc_taken, ARMV8_PMUV3_PERFCTR_EXC_TAKEN),
ARMV8_EVENT_ATTR(exc_return, ARMV8_PMUV3_PERFCTR_EXC_RETURN),
ARMV8_EVENT_ATTR(cid_write_retired, ARMV8_PMUV3_PERFCTR_CID_WRITE_RETIRED),
ARMV8_EVENT_ATTR(pc_write_retired, ARMV8_PMUV3_PERFCTR_PC_WRITE_RETIRED),
ARMV8_EVENT_ATTR(br_immed_retired, ARMV8_PMUV3_PERFCTR_BR_IMMED_RETIRED),
ARMV8_EVENT_ATTR(br_return_retired, ARMV8_PMUV3_PERFCTR_BR_RETURN_RETIRED),
ARMV8_EVENT_ATTR(unaligned_ldst_retired, ARMV8_PMUV3_PERFCTR_UNALIGNED_LDST_RETIRED),
ARMV8_EVENT_ATTR(br_mis_pred, ARMV8_PMUV3_PERFCTR_BR_MIS_PRED),
ARMV8_EVENT_ATTR(cpu_cycles, ARMV8_PMUV3_PERFCTR_CPU_CYCLES),
ARMV8_EVENT_ATTR(br_pred, ARMV8_PMUV3_PERFCTR_BR_PRED),
ARMV8_EVENT_ATTR(mem_access, ARMV8_PMUV3_PERFCTR_MEM_ACCESS),
ARMV8_EVENT_ATTR(l1i_cache, ARMV8_PMUV3_PERFCTR_L1I_CACHE),
ARMV8_EVENT_ATTR(l1d_cache_wb, ARMV8_PMUV3_PERFCTR_L1D_CACHE_WB),
ARMV8_EVENT_ATTR(l2d_cache, ARMV8_PMUV3_PERFCTR_L2D_CACHE),
ARMV8_EVENT_ATTR(l2d_cache_refill, ARMV8_PMUV3_PERFCTR_L2D_CACHE_REFILL),
ARMV8_EVENT_ATTR(l2d_cache_wb, ARMV8_PMUV3_PERFCTR_L2D_CACHE_WB),
ARMV8_EVENT_ATTR(bus_access, ARMV8_PMUV3_PERFCTR_BUS_ACCESS),
ARMV8_EVENT_ATTR(memory_error, ARMV8_PMUV3_PERFCTR_MEMORY_ERROR),
ARMV8_EVENT_ATTR(inst_spec, ARMV8_PMUV3_PERFCTR_INST_SPEC),
ARMV8_EVENT_ATTR(ttbr_write_retired, ARMV8_PMUV3_PERFCTR_TTBR_WRITE_RETIRED),
ARMV8_EVENT_ATTR(bus_cycles, ARMV8_PMUV3_PERFCTR_BUS_CYCLES),
/* Don't expose the chain event in /sys, since it's useless in isolation */
ARMV8_EVENT_ATTR(l1d_cache_allocate, ARMV8_PMUV3_PERFCTR_L1D_CACHE_ALLOCATE),
ARMV8_EVENT_ATTR(l2d_cache_allocate, ARMV8_PMUV3_PERFCTR_L2D_CACHE_ALLOCATE),
ARMV8_EVENT_ATTR(br_retired, ARMV8_PMUV3_PERFCTR_BR_RETIRED),
ARMV8_EVENT_ATTR(br_mis_pred_retired, ARMV8_PMUV3_PERFCTR_BR_MIS_PRED_RETIRED),
ARMV8_EVENT_ATTR(stall_frontend, ARMV8_PMUV3_PERFCTR_STALL_FRONTEND),
ARMV8_EVENT_ATTR(stall_backend, ARMV8_PMUV3_PERFCTR_STALL_BACKEND),
ARMV8_EVENT_ATTR(l1d_tlb, ARMV8_PMUV3_PERFCTR_L1D_TLB),
ARMV8_EVENT_ATTR(l1i_tlb, ARMV8_PMUV3_PERFCTR_L1I_TLB),
ARMV8_EVENT_ATTR(l2i_cache, ARMV8_PMUV3_PERFCTR_L2I_CACHE),
ARMV8_EVENT_ATTR(l2i_cache_refill, ARMV8_PMUV3_PERFCTR_L2I_CACHE_REFILL),
ARMV8_EVENT_ATTR(l3d_cache_allocate, ARMV8_PMUV3_PERFCTR_L3D_CACHE_ALLOCATE),
ARMV8_EVENT_ATTR(l3d_cache_refill, ARMV8_PMUV3_PERFCTR_L3D_CACHE_REFILL),
ARMV8_EVENT_ATTR(l3d_cache, ARMV8_PMUV3_PERFCTR_L3D_CACHE),
ARMV8_EVENT_ATTR(l3d_cache_wb, ARMV8_PMUV3_PERFCTR_L3D_CACHE_WB),
ARMV8_EVENT_ATTR(l2d_tlb_refill, ARMV8_PMUV3_PERFCTR_L2D_TLB_REFILL),
ARMV8_EVENT_ATTR(l2i_tlb_refill, ARMV8_PMUV3_PERFCTR_L2I_TLB_REFILL),
ARMV8_EVENT_ATTR(l2d_tlb, ARMV8_PMUV3_PERFCTR_L2D_TLB),
ARMV8_EVENT_ATTR(l2i_tlb, ARMV8_PMUV3_PERFCTR_L2I_TLB),
ARMV8_EVENT_ATTR(remote_access, ARMV8_PMUV3_PERFCTR_REMOTE_ACCESS),
ARMV8_EVENT_ATTR(ll_cache, ARMV8_PMUV3_PERFCTR_LL_CACHE),
ARMV8_EVENT_ATTR(ll_cache_miss, ARMV8_PMUV3_PERFCTR_LL_CACHE_MISS),
ARMV8_EVENT_ATTR(dtlb_walk, ARMV8_PMUV3_PERFCTR_DTLB_WALK),
ARMV8_EVENT_ATTR(itlb_walk, ARMV8_PMUV3_PERFCTR_ITLB_WALK),
ARMV8_EVENT_ATTR(ll_cache_rd, ARMV8_PMUV3_PERFCTR_LL_CACHE_RD),
ARMV8_EVENT_ATTR(ll_cache_miss_rd, ARMV8_PMUV3_PERFCTR_LL_CACHE_MISS_RD),
ARMV8_EVENT_ATTR(remote_access_rd, ARMV8_PMUV3_PERFCTR_REMOTE_ACCESS_RD),
ARMV8_EVENT_ATTR(l1d_cache_lmiss_rd, ARMV8_PMUV3_PERFCTR_L1D_CACHE_LMISS_RD),
ARMV8_EVENT_ATTR(op_retired, ARMV8_PMUV3_PERFCTR_OP_RETIRED),
ARMV8_EVENT_ATTR(op_spec, ARMV8_PMUV3_PERFCTR_OP_SPEC),
ARMV8_EVENT_ATTR(stall, ARMV8_PMUV3_PERFCTR_STALL),
ARMV8_EVENT_ATTR(stall_slot_backend, ARMV8_PMUV3_PERFCTR_STALL_SLOT_BACKEND),
ARMV8_EVENT_ATTR(stall_slot_frontend, ARMV8_PMUV3_PERFCTR_STALL_SLOT_FRONTEND),
ARMV8_EVENT_ATTR(stall_slot, ARMV8_PMUV3_PERFCTR_STALL_SLOT),
ARMV8_EVENT_ATTR(sample_pop, ARMV8_SPE_PERFCTR_SAMPLE_POP),
ARMV8_EVENT_ATTR(sample_feed, ARMV8_SPE_PERFCTR_SAMPLE_FEED),
ARMV8_EVENT_ATTR(sample_filtrate, ARMV8_SPE_PERFCTR_SAMPLE_FILTRATE),
ARMV8_EVENT_ATTR(sample_collision, ARMV8_SPE_PERFCTR_SAMPLE_COLLISION),
ARMV8_EVENT_ATTR(cnt_cycles, ARMV8_AMU_PERFCTR_CNT_CYCLES),
ARMV8_EVENT_ATTR(stall_backend_mem, ARMV8_AMU_PERFCTR_STALL_BACKEND_MEM),
ARMV8_EVENT_ATTR(l1i_cache_lmiss, ARMV8_PMUV3_PERFCTR_L1I_CACHE_LMISS),
ARMV8_EVENT_ATTR(l2d_cache_lmiss_rd, ARMV8_PMUV3_PERFCTR_L2D_CACHE_LMISS_RD),
ARMV8_EVENT_ATTR(l2i_cache_lmiss, ARMV8_PMUV3_PERFCTR_L2I_CACHE_LMISS),
ARMV8_EVENT_ATTR(l3d_cache_lmiss_rd, ARMV8_PMUV3_PERFCTR_L3D_CACHE_LMISS_RD),
ARMV8_EVENT_ATTR(trb_wrap, ARMV8_PMUV3_PERFCTR_TRB_WRAP),
ARMV8_EVENT_ATTR(trb_trig, ARMV8_PMUV3_PERFCTR_TRB_TRIG),
ARMV8_EVENT_ATTR(trcextout0, ARMV8_PMUV3_PERFCTR_TRCEXTOUT0),
ARMV8_EVENT_ATTR(trcextout1, ARMV8_PMUV3_PERFCTR_TRCEXTOUT1),
ARMV8_EVENT_ATTR(trcextout2, ARMV8_PMUV3_PERFCTR_TRCEXTOUT2),
ARMV8_EVENT_ATTR(trcextout3, ARMV8_PMUV3_PERFCTR_TRCEXTOUT3),
ARMV8_EVENT_ATTR(cti_trigout4, ARMV8_PMUV3_PERFCTR_CTI_TRIGOUT4),
ARMV8_EVENT_ATTR(cti_trigout5, ARMV8_PMUV3_PERFCTR_CTI_TRIGOUT5),
ARMV8_EVENT_ATTR(cti_trigout6, ARMV8_PMUV3_PERFCTR_CTI_TRIGOUT6),
ARMV8_EVENT_ATTR(cti_trigout7, ARMV8_PMUV3_PERFCTR_CTI_TRIGOUT7),
ARMV8_EVENT_ATTR(ldst_align_lat, ARMV8_PMUV3_PERFCTR_LDST_ALIGN_LAT),
ARMV8_EVENT_ATTR(ld_align_lat, ARMV8_PMUV3_PERFCTR_LD_ALIGN_LAT),
ARMV8_EVENT_ATTR(st_align_lat, ARMV8_PMUV3_PERFCTR_ST_ALIGN_LAT),
ARMV8_EVENT_ATTR(mem_access_checked, ARMV8_MTE_PERFCTR_MEM_ACCESS_CHECKED),
ARMV8_EVENT_ATTR(mem_access_checked_rd, ARMV8_MTE_PERFCTR_MEM_ACCESS_CHECKED_RD),
ARMV8_EVENT_ATTR(mem_access_checked_wr, ARMV8_MTE_PERFCTR_MEM_ACCESS_CHECKED_WR),
NULL,
};
static umode_t
armv8pmu_event_attr_is_visible(struct kobject *kobj,
struct attribute *attr, int unused)
{
struct device *dev = kobj_to_dev(kobj);
struct pmu *pmu = dev_get_drvdata(dev);
struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
struct perf_pmu_events_attr *pmu_attr;
pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr.attr);
if (pmu_attr->id < ARMV8_PMUV3_MAX_COMMON_EVENTS &&
test_bit(pmu_attr->id, cpu_pmu->pmceid_bitmap))
return attr->mode;
if (pmu_attr->id >= ARMV8_PMUV3_EXT_COMMON_EVENT_BASE) {
u64 id = pmu_attr->id - ARMV8_PMUV3_EXT_COMMON_EVENT_BASE;
if (id < ARMV8_PMUV3_MAX_COMMON_EVENTS &&
test_bit(id, cpu_pmu->pmceid_ext_bitmap))
return attr->mode;
}
return 0;
}
static const struct attribute_group armv8_pmuv3_events_attr_group = {
.name = "events",
.attrs = armv8_pmuv3_event_attrs,
.is_visible = armv8pmu_event_attr_is_visible,
};
/* User ABI */
#define ATTR_CFG_FLD_event_CFG config
#define ATTR_CFG_FLD_event_LO 0
#define ATTR_CFG_FLD_event_HI 15
#define ATTR_CFG_FLD_long_CFG config1
#define ATTR_CFG_FLD_long_LO 0
#define ATTR_CFG_FLD_long_HI 0
#define ATTR_CFG_FLD_rdpmc_CFG config1
#define ATTR_CFG_FLD_rdpmc_LO 1
#define ATTR_CFG_FLD_rdpmc_HI 1
arm64: perf: Add support for event counting threshold FEAT_PMUv3_TH (Armv8.8) permits a PMU counter to increment only on events whose count meets a specified threshold condition. For example if PMEVTYPERn.TC (Threshold Control) is set to 0b101 (Greater than or equal, count), and the threshold is set to 2, then the PMU counter will now only increment by 1 when an event would have previously incremented the PMU counter by 2 or more on a single processor cycle. Three new Perf event config fields, 'threshold', 'threshold_compare' and 'threshold_count' have been added to control the feature. threshold_compare maps to the upper two bits of PMEVTYPERn.TC and threshold_count maps to the first bit of TC. These separate attributes have been picked rather than enumerating all the possible combinations of the TC field as in the Arm ARM. The attributes would be used on a Perf command line like this: $ perf stat -e stall_slot/threshold=2,threshold_compare=2/ A new capability for reading out the maximum supported threshold value has also been added: $ cat /sys/bus/event_source/devices/armv8_pmuv3/caps/threshold_max 0x000000ff If a threshold higher than threshold_max is provided, then an error is generated. If FEAT_PMUv3_TH isn't implemented or a 32 bit kernel is running, then threshold_max reads zero, and attempting to set a threshold value will also result in an error. The threshold is per PMU counter, and there are potentially different threshold_max values per PMU type on heterogeneous systems. Bits higher than 32 now need to be written into PMEVTYPER, so armv8pmu_write_evtype() has to be updated to take an unsigned long value rather than u32 which gives the correct behavior on both aarch32 and 64. Signed-off-by: James Clark <james.clark@arm.com> Link: https://lore.kernel.org/r/20231211161331.1277825-11-james.clark@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2023-12-11 16:13:22 +00:00
#define ATTR_CFG_FLD_threshold_count_CFG config1 /* PMEVTYPER.TC[0] */
#define ATTR_CFG_FLD_threshold_count_LO 2
#define ATTR_CFG_FLD_threshold_count_HI 2
#define ATTR_CFG_FLD_threshold_compare_CFG config1 /* PMEVTYPER.TC[2:1] */
#define ATTR_CFG_FLD_threshold_compare_LO 3
#define ATTR_CFG_FLD_threshold_compare_HI 4
#define ATTR_CFG_FLD_threshold_CFG config1 /* PMEVTYPER.TH */
#define ATTR_CFG_FLD_threshold_LO 5
#define ATTR_CFG_FLD_threshold_HI 16
GEN_PMU_FORMAT_ATTR(event);
GEN_PMU_FORMAT_ATTR(long);
GEN_PMU_FORMAT_ATTR(rdpmc);
arm64: perf: Add support for event counting threshold FEAT_PMUv3_TH (Armv8.8) permits a PMU counter to increment only on events whose count meets a specified threshold condition. For example if PMEVTYPERn.TC (Threshold Control) is set to 0b101 (Greater than or equal, count), and the threshold is set to 2, then the PMU counter will now only increment by 1 when an event would have previously incremented the PMU counter by 2 or more on a single processor cycle. Three new Perf event config fields, 'threshold', 'threshold_compare' and 'threshold_count' have been added to control the feature. threshold_compare maps to the upper two bits of PMEVTYPERn.TC and threshold_count maps to the first bit of TC. These separate attributes have been picked rather than enumerating all the possible combinations of the TC field as in the Arm ARM. The attributes would be used on a Perf command line like this: $ perf stat -e stall_slot/threshold=2,threshold_compare=2/ A new capability for reading out the maximum supported threshold value has also been added: $ cat /sys/bus/event_source/devices/armv8_pmuv3/caps/threshold_max 0x000000ff If a threshold higher than threshold_max is provided, then an error is generated. If FEAT_PMUv3_TH isn't implemented or a 32 bit kernel is running, then threshold_max reads zero, and attempting to set a threshold value will also result in an error. The threshold is per PMU counter, and there are potentially different threshold_max values per PMU type on heterogeneous systems. Bits higher than 32 now need to be written into PMEVTYPER, so armv8pmu_write_evtype() has to be updated to take an unsigned long value rather than u32 which gives the correct behavior on both aarch32 and 64. Signed-off-by: James Clark <james.clark@arm.com> Link: https://lore.kernel.org/r/20231211161331.1277825-11-james.clark@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2023-12-11 16:13:22 +00:00
GEN_PMU_FORMAT_ATTR(threshold_count);
GEN_PMU_FORMAT_ATTR(threshold_compare);
GEN_PMU_FORMAT_ATTR(threshold);
static int sysctl_perf_user_access __read_mostly;
static bool armv8pmu_event_is_64bit(struct perf_event *event)
{
return ATTR_CFG_GET_FLD(&event->attr, long);
}
static bool armv8pmu_event_want_user_access(struct perf_event *event)
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
{
return ATTR_CFG_GET_FLD(&event->attr, rdpmc);
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
}
static u32 armv8pmu_event_get_threshold(struct perf_event_attr *attr)
{
return ATTR_CFG_GET_FLD(attr, threshold);
}
arm64: perf: Add support for event counting threshold FEAT_PMUv3_TH (Armv8.8) permits a PMU counter to increment only on events whose count meets a specified threshold condition. For example if PMEVTYPERn.TC (Threshold Control) is set to 0b101 (Greater than or equal, count), and the threshold is set to 2, then the PMU counter will now only increment by 1 when an event would have previously incremented the PMU counter by 2 or more on a single processor cycle. Three new Perf event config fields, 'threshold', 'threshold_compare' and 'threshold_count' have been added to control the feature. threshold_compare maps to the upper two bits of PMEVTYPERn.TC and threshold_count maps to the first bit of TC. These separate attributes have been picked rather than enumerating all the possible combinations of the TC field as in the Arm ARM. The attributes would be used on a Perf command line like this: $ perf stat -e stall_slot/threshold=2,threshold_compare=2/ A new capability for reading out the maximum supported threshold value has also been added: $ cat /sys/bus/event_source/devices/armv8_pmuv3/caps/threshold_max 0x000000ff If a threshold higher than threshold_max is provided, then an error is generated. If FEAT_PMUv3_TH isn't implemented or a 32 bit kernel is running, then threshold_max reads zero, and attempting to set a threshold value will also result in an error. The threshold is per PMU counter, and there are potentially different threshold_max values per PMU type on heterogeneous systems. Bits higher than 32 now need to be written into PMEVTYPER, so armv8pmu_write_evtype() has to be updated to take an unsigned long value rather than u32 which gives the correct behavior on both aarch32 and 64. Signed-off-by: James Clark <james.clark@arm.com> Link: https://lore.kernel.org/r/20231211161331.1277825-11-james.clark@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2023-12-11 16:13:22 +00:00
static u8 armv8pmu_event_threshold_control(struct perf_event_attr *attr)
{
u8 th_compare = ATTR_CFG_GET_FLD(attr, threshold_compare);
u8 th_count = ATTR_CFG_GET_FLD(attr, threshold_count);
/*
* The count bit is always the bottom bit of the full control field, and
* the comparison is the upper two bits, but it's not explicitly
* labelled in the Arm ARM. For the Perf interface we split it into two
* fields, so reconstruct it here.
*/
return (th_compare << 1) | th_count;
}
static struct attribute *armv8_pmuv3_format_attrs[] = {
&format_attr_event.attr,
&format_attr_long.attr,
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
&format_attr_rdpmc.attr,
arm64: perf: Add support for event counting threshold FEAT_PMUv3_TH (Armv8.8) permits a PMU counter to increment only on events whose count meets a specified threshold condition. For example if PMEVTYPERn.TC (Threshold Control) is set to 0b101 (Greater than or equal, count), and the threshold is set to 2, then the PMU counter will now only increment by 1 when an event would have previously incremented the PMU counter by 2 or more on a single processor cycle. Three new Perf event config fields, 'threshold', 'threshold_compare' and 'threshold_count' have been added to control the feature. threshold_compare maps to the upper two bits of PMEVTYPERn.TC and threshold_count maps to the first bit of TC. These separate attributes have been picked rather than enumerating all the possible combinations of the TC field as in the Arm ARM. The attributes would be used on a Perf command line like this: $ perf stat -e stall_slot/threshold=2,threshold_compare=2/ A new capability for reading out the maximum supported threshold value has also been added: $ cat /sys/bus/event_source/devices/armv8_pmuv3/caps/threshold_max 0x000000ff If a threshold higher than threshold_max is provided, then an error is generated. If FEAT_PMUv3_TH isn't implemented or a 32 bit kernel is running, then threshold_max reads zero, and attempting to set a threshold value will also result in an error. The threshold is per PMU counter, and there are potentially different threshold_max values per PMU type on heterogeneous systems. Bits higher than 32 now need to be written into PMEVTYPER, so armv8pmu_write_evtype() has to be updated to take an unsigned long value rather than u32 which gives the correct behavior on both aarch32 and 64. Signed-off-by: James Clark <james.clark@arm.com> Link: https://lore.kernel.org/r/20231211161331.1277825-11-james.clark@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2023-12-11 16:13:22 +00:00
&format_attr_threshold.attr,
&format_attr_threshold_compare.attr,
&format_attr_threshold_count.attr,
NULL,
};
static const struct attribute_group armv8_pmuv3_format_attr_group = {
.name = "format",
.attrs = armv8_pmuv3_format_attrs,
};
static ssize_t slots_show(struct device *dev, struct device_attribute *attr,
char *page)
{
struct pmu *pmu = dev_get_drvdata(dev);
struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
u32 slots = FIELD_GET(ARMV8_PMU_SLOTS, cpu_pmu->reg_pmmir);
return sysfs_emit(page, "0x%08x\n", slots);
}
static DEVICE_ATTR_RO(slots);
static ssize_t bus_slots_show(struct device *dev, struct device_attribute *attr,
char *page)
{
struct pmu *pmu = dev_get_drvdata(dev);
struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
u32 bus_slots = FIELD_GET(ARMV8_PMU_BUS_SLOTS, cpu_pmu->reg_pmmir);
return sysfs_emit(page, "0x%08x\n", bus_slots);
}
static DEVICE_ATTR_RO(bus_slots);
static ssize_t bus_width_show(struct device *dev, struct device_attribute *attr,
char *page)
{
struct pmu *pmu = dev_get_drvdata(dev);
struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
u32 bus_width = FIELD_GET(ARMV8_PMU_BUS_WIDTH, cpu_pmu->reg_pmmir);
u32 val = 0;
/* Encoded as Log2(number of bytes), plus one */
if (bus_width > 2 && bus_width < 13)
val = 1 << (bus_width - 1);
return sysfs_emit(page, "0x%08x\n", val);
}
static DEVICE_ATTR_RO(bus_width);
arm64: perf: Add support for event counting threshold FEAT_PMUv3_TH (Armv8.8) permits a PMU counter to increment only on events whose count meets a specified threshold condition. For example if PMEVTYPERn.TC (Threshold Control) is set to 0b101 (Greater than or equal, count), and the threshold is set to 2, then the PMU counter will now only increment by 1 when an event would have previously incremented the PMU counter by 2 or more on a single processor cycle. Three new Perf event config fields, 'threshold', 'threshold_compare' and 'threshold_count' have been added to control the feature. threshold_compare maps to the upper two bits of PMEVTYPERn.TC and threshold_count maps to the first bit of TC. These separate attributes have been picked rather than enumerating all the possible combinations of the TC field as in the Arm ARM. The attributes would be used on a Perf command line like this: $ perf stat -e stall_slot/threshold=2,threshold_compare=2/ A new capability for reading out the maximum supported threshold value has also been added: $ cat /sys/bus/event_source/devices/armv8_pmuv3/caps/threshold_max 0x000000ff If a threshold higher than threshold_max is provided, then an error is generated. If FEAT_PMUv3_TH isn't implemented or a 32 bit kernel is running, then threshold_max reads zero, and attempting to set a threshold value will also result in an error. The threshold is per PMU counter, and there are potentially different threshold_max values per PMU type on heterogeneous systems. Bits higher than 32 now need to be written into PMEVTYPER, so armv8pmu_write_evtype() has to be updated to take an unsigned long value rather than u32 which gives the correct behavior on both aarch32 and 64. Signed-off-by: James Clark <james.clark@arm.com> Link: https://lore.kernel.org/r/20231211161331.1277825-11-james.clark@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2023-12-11 16:13:22 +00:00
static u32 threshold_max(struct arm_pmu *cpu_pmu)
{
/*
* PMMIR.THWIDTH is readable and non-zero on aarch32, but it would be
* impossible to write the threshold in the upper 32 bits of PMEVTYPER.
*/
if (IS_ENABLED(CONFIG_ARM))
return 0;
/*
* The largest value that can be written to PMEVTYPER<n>_EL0.TH is
* (2 ^ PMMIR.THWIDTH) - 1.
*/
return (1 << FIELD_GET(ARMV8_PMU_THWIDTH, cpu_pmu->reg_pmmir)) - 1;
}
static ssize_t threshold_max_show(struct device *dev,
struct device_attribute *attr, char *page)
{
struct pmu *pmu = dev_get_drvdata(dev);
struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
return sysfs_emit(page, "0x%08x\n", threshold_max(cpu_pmu));
}
static DEVICE_ATTR_RO(threshold_max);
static struct attribute *armv8_pmuv3_caps_attrs[] = {
&dev_attr_slots.attr,
&dev_attr_bus_slots.attr,
&dev_attr_bus_width.attr,
arm64: perf: Add support for event counting threshold FEAT_PMUv3_TH (Armv8.8) permits a PMU counter to increment only on events whose count meets a specified threshold condition. For example if PMEVTYPERn.TC (Threshold Control) is set to 0b101 (Greater than or equal, count), and the threshold is set to 2, then the PMU counter will now only increment by 1 when an event would have previously incremented the PMU counter by 2 or more on a single processor cycle. Three new Perf event config fields, 'threshold', 'threshold_compare' and 'threshold_count' have been added to control the feature. threshold_compare maps to the upper two bits of PMEVTYPERn.TC and threshold_count maps to the first bit of TC. These separate attributes have been picked rather than enumerating all the possible combinations of the TC field as in the Arm ARM. The attributes would be used on a Perf command line like this: $ perf stat -e stall_slot/threshold=2,threshold_compare=2/ A new capability for reading out the maximum supported threshold value has also been added: $ cat /sys/bus/event_source/devices/armv8_pmuv3/caps/threshold_max 0x000000ff If a threshold higher than threshold_max is provided, then an error is generated. If FEAT_PMUv3_TH isn't implemented or a 32 bit kernel is running, then threshold_max reads zero, and attempting to set a threshold value will also result in an error. The threshold is per PMU counter, and there are potentially different threshold_max values per PMU type on heterogeneous systems. Bits higher than 32 now need to be written into PMEVTYPER, so armv8pmu_write_evtype() has to be updated to take an unsigned long value rather than u32 which gives the correct behavior on both aarch32 and 64. Signed-off-by: James Clark <james.clark@arm.com> Link: https://lore.kernel.org/r/20231211161331.1277825-11-james.clark@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2023-12-11 16:13:22 +00:00
&dev_attr_threshold_max.attr,
NULL,
};
static const struct attribute_group armv8_pmuv3_caps_attr_group = {
.name = "caps",
.attrs = armv8_pmuv3_caps_attrs,
};
/*
* We unconditionally enable ARMv8.5-PMU long event counter support
* (64-bit events) where supported. Indicate if this arm_pmu has long
* event counter support.
*
* On AArch32, long counters make no sense (you can't access the top
* bits), so we only enable this on AArch64.
*/
static bool armv8pmu_has_long_event(struct arm_pmu *cpu_pmu)
{
return (IS_ENABLED(CONFIG_ARM64) && is_pmuv3p5(cpu_pmu->pmuver));
}
static bool armv8pmu_event_has_user_read(struct perf_event *event)
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
{
return event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT;
}
/*
* We must chain two programmable counters for 64 bit events,
* except when we have allocated the 64bit cycle counter (for CPU
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
* cycles event) or when user space counter access is enabled.
*/
static bool armv8pmu_event_is_chained(struct perf_event *event)
{
int idx = event->hw.idx;
struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
return !armv8pmu_event_has_user_read(event) &&
armv8pmu_event_is_64bit(event) &&
!armv8pmu_has_long_event(cpu_pmu) &&
(idx < ARMV8_PMU_MAX_GENERAL_COUNTERS);
}
/*
* ARMv8 low level PMU access
*/
static u64 armv8pmu_pmcr_read(void)
{
return read_pmcr();
}
static void armv8pmu_pmcr_write(u64 val)
{
val &= ARMV8_PMU_PMCR_MASK;
isb();
write_pmcr(val);
}
static int armv8pmu_has_overflowed(u64 pmovsr)
{
return !!(pmovsr & ARMV8_PMU_OVERFLOWED_MASK);
}
static int armv8pmu_counter_has_overflowed(u64 pmnc, int idx)
{
return !!(pmnc & BIT(idx));
}
static u64 armv8pmu_read_evcntr(int idx)
{
return read_pmevcntrn(idx);
}
static u64 armv8pmu_read_hw_counter(struct perf_event *event)
{
int idx = event->hw.idx;
u64 val = armv8pmu_read_evcntr(idx);
if (armv8pmu_event_is_chained(event))
val = (val << 32) | armv8pmu_read_evcntr(idx - 1);
return val;
}
/*
* The cycle counter is always a 64-bit counter. When ARMV8_PMU_PMCR_LP
* is set the event counters also become 64-bit counters. Unless the
* user has requested a long counter (attr.config1) then we want to
* interrupt upon 32-bit overflow - we achieve this by applying a bias.
*/
static bool armv8pmu_event_needs_bias(struct perf_event *event)
{
struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
struct hw_perf_event *hwc = &event->hw;
int idx = hwc->idx;
if (armv8pmu_event_is_64bit(event))
return false;
if (armv8pmu_has_long_event(cpu_pmu) ||
idx >= ARMV8_PMU_MAX_GENERAL_COUNTERS)
return true;
return false;
}
static u64 armv8pmu_bias_long_counter(struct perf_event *event, u64 value)
{
if (armv8pmu_event_needs_bias(event))
value |= GENMASK_ULL(63, 32);
return value;
}
static u64 armv8pmu_unbias_long_counter(struct perf_event *event, u64 value)
{
if (armv8pmu_event_needs_bias(event))
value &= ~GENMASK_ULL(63, 32);
return value;
}
static u64 armv8pmu_read_counter(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
int idx = hwc->idx;
u64 value;
if (idx == ARMV8_PMU_CYCLE_IDX)
value = read_pmccntr();
else if (idx == ARMV8_PMU_INSTR_IDX)
value = read_pmicntr();
else
value = armv8pmu_read_hw_counter(event);
return armv8pmu_unbias_long_counter(event, value);
}
static void armv8pmu_write_evcntr(int idx, u64 value)
{
write_pmevcntrn(idx, value);
}
static void armv8pmu_write_hw_counter(struct perf_event *event,
u64 value)
{
int idx = event->hw.idx;
if (armv8pmu_event_is_chained(event)) {
armv8pmu_write_evcntr(idx, upper_32_bits(value));
armv8pmu_write_evcntr(idx - 1, lower_32_bits(value));
} else {
armv8pmu_write_evcntr(idx, value);
}
}
static void armv8pmu_write_counter(struct perf_event *event, u64 value)
{
struct hw_perf_event *hwc = &event->hw;
int idx = hwc->idx;
value = armv8pmu_bias_long_counter(event, value);
if (idx == ARMV8_PMU_CYCLE_IDX)
write_pmccntr(value);
else if (idx == ARMV8_PMU_INSTR_IDX)
write_pmicntr(value);
else
armv8pmu_write_hw_counter(event, value);
}
arm64: perf: Add support for event counting threshold FEAT_PMUv3_TH (Armv8.8) permits a PMU counter to increment only on events whose count meets a specified threshold condition. For example if PMEVTYPERn.TC (Threshold Control) is set to 0b101 (Greater than or equal, count), and the threshold is set to 2, then the PMU counter will now only increment by 1 when an event would have previously incremented the PMU counter by 2 or more on a single processor cycle. Three new Perf event config fields, 'threshold', 'threshold_compare' and 'threshold_count' have been added to control the feature. threshold_compare maps to the upper two bits of PMEVTYPERn.TC and threshold_count maps to the first bit of TC. These separate attributes have been picked rather than enumerating all the possible combinations of the TC field as in the Arm ARM. The attributes would be used on a Perf command line like this: $ perf stat -e stall_slot/threshold=2,threshold_compare=2/ A new capability for reading out the maximum supported threshold value has also been added: $ cat /sys/bus/event_source/devices/armv8_pmuv3/caps/threshold_max 0x000000ff If a threshold higher than threshold_max is provided, then an error is generated. If FEAT_PMUv3_TH isn't implemented or a 32 bit kernel is running, then threshold_max reads zero, and attempting to set a threshold value will also result in an error. The threshold is per PMU counter, and there are potentially different threshold_max values per PMU type on heterogeneous systems. Bits higher than 32 now need to be written into PMEVTYPER, so armv8pmu_write_evtype() has to be updated to take an unsigned long value rather than u32 which gives the correct behavior on both aarch32 and 64. Signed-off-by: James Clark <james.clark@arm.com> Link: https://lore.kernel.org/r/20231211161331.1277825-11-james.clark@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2023-12-11 16:13:22 +00:00
static void armv8pmu_write_evtype(int idx, unsigned long val)
{
unsigned long mask = ARMV8_PMU_EVTYPE_EVENT |
ARMV8_PMU_INCLUDE_EL2 |
ARMV8_PMU_EXCLUDE_EL0 |
ARMV8_PMU_EXCLUDE_EL1;
arm64: perf: Avoid PMXEV* indirection Currently we access the counter registers and their respective type registers indirectly. This requires us to write to PMSELR, issue an ISB, then access the relevant PMXEV* registers. This is unfortunate, because: * Under virtualization, accessing one register requires two traps to the hypervisor, even though we could access the register directly with a single trap. * We have to issue an ISB which we could otherwise avoid the cost of. * When we use NMIs, the NMI handler will have to save/restore the select register in case the code it preempted was attempting to access a counter or its type register. We can avoid these issues by directly accessing the relevant registers. This patch adds helpers to do so. In armv8pmu_enable_event() we still need the ISB to prevent the PE from reordering the write to PMINTENSET_EL1 register. If the interrupt is enabled before we disable the counter and the new event is configured, we might get an interrupt triggered by the previously programmed event overflowing, but which we wrongly attribute to the event that we are enabling. Execute an ISB after we disable the counter. In the process, remove the comment that refers to the ARMv7 PMU. [Julien T.: Don't inline read/write functions to avoid big code-size increase, remove unused read_pmevtypern function, fix counter index issue.] [Alexandru E.: Removed comment, removed trailing semicolons in macros, added ISB] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Tested-by: Sumit Garg <sumit.garg@linaro.org> (Developerbox) Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200924110706.254996-3-alexandru.elisei@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-24 11:07:01 +00:00
if (IS_ENABLED(CONFIG_ARM64))
mask |= ARMV8_PMU_EVTYPE_TC | ARMV8_PMU_EVTYPE_TH;
val &= mask;
write_pmevtypern(idx, val);
}
static void armv8pmu_write_event_type(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
int idx = hwc->idx;
/*
* For chained events, the low counter is programmed to count
* the event of interest and the high counter is programmed
* with CHAIN event code with filters set to count at all ELs.
*/
if (armv8pmu_event_is_chained(event)) {
u32 chain_evt = ARMV8_PMUV3_PERFCTR_CHAIN |
ARMV8_PMU_INCLUDE_EL2;
armv8pmu_write_evtype(idx - 1, hwc->config_base);
armv8pmu_write_evtype(idx, chain_evt);
} else {
if (idx == ARMV8_PMU_CYCLE_IDX)
write_pmccfiltr(hwc->config_base);
else if (idx == ARMV8_PMU_INSTR_IDX)
write_pmicfiltr(hwc->config_base);
arm64: perf: Avoid PMXEV* indirection Currently we access the counter registers and their respective type registers indirectly. This requires us to write to PMSELR, issue an ISB, then access the relevant PMXEV* registers. This is unfortunate, because: * Under virtualization, accessing one register requires two traps to the hypervisor, even though we could access the register directly with a single trap. * We have to issue an ISB which we could otherwise avoid the cost of. * When we use NMIs, the NMI handler will have to save/restore the select register in case the code it preempted was attempting to access a counter or its type register. We can avoid these issues by directly accessing the relevant registers. This patch adds helpers to do so. In armv8pmu_enable_event() we still need the ISB to prevent the PE from reordering the write to PMINTENSET_EL1 register. If the interrupt is enabled before we disable the counter and the new event is configured, we might get an interrupt triggered by the previously programmed event overflowing, but which we wrongly attribute to the event that we are enabling. Execute an ISB after we disable the counter. In the process, remove the comment that refers to the ARMv7 PMU. [Julien T.: Don't inline read/write functions to avoid big code-size increase, remove unused read_pmevtypern function, fix counter index issue.] [Alexandru E.: Removed comment, removed trailing semicolons in macros, added ISB] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Tested-by: Sumit Garg <sumit.garg@linaro.org> (Developerbox) Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200924110706.254996-3-alexandru.elisei@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-24 11:07:01 +00:00
else
armv8pmu_write_evtype(idx, hwc->config_base);
}
}
static u64 armv8pmu_event_cnten_mask(struct perf_event *event)
{
int counter = event->hw.idx;
u64 mask = BIT(counter);
if (armv8pmu_event_is_chained(event))
mask |= BIT(counter - 1);
return mask;
}
static void armv8pmu_enable_counter(u64 mask)
{
2020-09-24 11:07:00 +00:00
/*
* Make sure event configuration register writes are visible before we
* enable the counter.
* */
isb();
write_pmcntenset(mask);
}
static void armv8pmu_enable_event_counter(struct perf_event *event)
{
struct perf_event_attr *attr = &event->attr;
u64 mask = armv8pmu_event_cnten_mask(event);
kvm_set_pmu_events(mask, attr);
/* We rely on the hypervisor switch code to enable guest counters */
if (!kvm_pmu_counter_deferred(attr))
armv8pmu_enable_counter(mask);
}
static void armv8pmu_disable_counter(u64 mask)
{
write_pmcntenclr(mask);
arm64: perf: Avoid PMXEV* indirection Currently we access the counter registers and their respective type registers indirectly. This requires us to write to PMSELR, issue an ISB, then access the relevant PMXEV* registers. This is unfortunate, because: * Under virtualization, accessing one register requires two traps to the hypervisor, even though we could access the register directly with a single trap. * We have to issue an ISB which we could otherwise avoid the cost of. * When we use NMIs, the NMI handler will have to save/restore the select register in case the code it preempted was attempting to access a counter or its type register. We can avoid these issues by directly accessing the relevant registers. This patch adds helpers to do so. In armv8pmu_enable_event() we still need the ISB to prevent the PE from reordering the write to PMINTENSET_EL1 register. If the interrupt is enabled before we disable the counter and the new event is configured, we might get an interrupt triggered by the previously programmed event overflowing, but which we wrongly attribute to the event that we are enabling. Execute an ISB after we disable the counter. In the process, remove the comment that refers to the ARMv7 PMU. [Julien T.: Don't inline read/write functions to avoid big code-size increase, remove unused read_pmevtypern function, fix counter index issue.] [Alexandru E.: Removed comment, removed trailing semicolons in macros, added ISB] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Tested-by: Sumit Garg <sumit.garg@linaro.org> (Developerbox) Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200924110706.254996-3-alexandru.elisei@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-24 11:07:01 +00:00
/*
* Make sure the effects of disabling the counter are visible before we
* start configuring the event.
*/
isb();
}
static void armv8pmu_disable_event_counter(struct perf_event *event)
{
struct perf_event_attr *attr = &event->attr;
u64 mask = armv8pmu_event_cnten_mask(event);
kvm_clr_pmu_events(mask);
/* We rely on the hypervisor switch code to disable guest counters */
if (!kvm_pmu_counter_deferred(attr))
armv8pmu_disable_counter(mask);
}
static void armv8pmu_enable_intens(u64 mask)
{
write_pmintenset(mask);
}
static void armv8pmu_enable_event_irq(struct perf_event *event)
{
armv8pmu_enable_intens(BIT(event->hw.idx));
}
static void armv8pmu_disable_intens(u64 mask)
{
write_pmintenclr(mask);
isb();
/* Clear the overflow flag in case an interrupt is pending. */
write_pmovsclr(mask);
isb();
}
static void armv8pmu_disable_event_irq(struct perf_event *event)
{
armv8pmu_disable_intens(BIT(event->hw.idx));
}
static u64 armv8pmu_getreset_flags(void)
{
u64 value;
/* Read */
value = read_pmovsclr();
/* Write to clear flags */
value &= ARMV8_PMU_OVERFLOWED_MASK;
write_pmovsclr(value);
return value;
}
static void update_pmuserenr(u64 val)
{
lockdep_assert_irqs_disabled();
/*
* The current PMUSERENR_EL0 value might be the value for the guest.
* If that's the case, have KVM keep tracking of the register value
* for the host EL0 so that KVM can restore it before returning to
* the host EL0. Otherwise, update the register now.
*/
if (kvm_set_pmuserenr(val))
return;
write_pmuserenr(val);
}
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
static void armv8pmu_disable_user_access(void)
{
update_pmuserenr(0);
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
}
static void armv8pmu_enable_user_access(struct arm_pmu *cpu_pmu)
{
int i;
struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
if (is_pmuv3p9(cpu_pmu->pmuver)) {
u64 mask = 0;
for_each_set_bit(i, cpuc->used_mask, ARMPMU_MAX_HWEVENTS) {
if (armv8pmu_event_has_user_read(cpuc->events[i]))
mask |= BIT(i);
}
write_pmuacr(mask);
} else {
/* Clear any unused counters to avoid leaking their contents */
for_each_andnot_bit(i, cpu_pmu->cntr_mask, cpuc->used_mask,
ARMPMU_MAX_HWEVENTS) {
if (i == ARMV8_PMU_CYCLE_IDX)
write_pmccntr(0);
else if (i == ARMV8_PMU_INSTR_IDX)
write_pmicntr(0);
else
armv8pmu_write_evcntr(i, 0);
}
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
}
update_pmuserenr(ARMV8_PMU_USERENR_ER | ARMV8_PMU_USERENR_CR | ARMV8_PMU_USERENR_UEN);
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
}
static void armv8pmu_enable_event(struct perf_event *event)
{
/*
* Enable counter and interrupt, and set the counter to count
* the event that we're interested in.
*/
armv8pmu_disable_event_counter(event);
armv8pmu_write_event_type(event);
armv8pmu_enable_event_irq(event);
armv8pmu_enable_event_counter(event);
}
static void armv8pmu_disable_event(struct perf_event *event)
{
armv8pmu_disable_event_counter(event);
armv8pmu_disable_event_irq(event);
}
static void armv8pmu_start(struct arm_pmu *cpu_pmu)
{
perf: Rewrite core context handling There have been various issues and limitations with the way perf uses (task) contexts to track events. Most notable is the single hardware PMU task context, which has resulted in a number of yucky things (both proposed and merged). Notably: - HW breakpoint PMU - ARM big.little PMU / Intel ADL PMU - Intel Branch Monitoring PMU - AMD IBS PMU - S390 cpum_cf PMU - PowerPC trace_imc PMU *Current design:* Currently we have a per task and per cpu perf_event_contexts: task_struct::perf_events_ctxp[] <-> perf_event_context <-> perf_cpu_context ^ | ^ | ^ `---------------------------------' | `--> pmu ---' v ^ perf_event ------' Each task has an array of pointers to a perf_event_context. Each perf_event_context has a direct relation to a PMU and a group of events for that PMU. The task related perf_event_context's have a pointer back to that task. Each PMU has a per-cpu pointer to a per-cpu perf_cpu_context, which includes a perf_event_context, which again has a direct relation to that PMU, and a group of events for that PMU. The perf_cpu_context also tracks which task context is currently associated with that CPU and includes a few other things like the hrtimer for rotation etc. Each perf_event is then associated with its PMU and one perf_event_context. *Proposed design:* New design proposed by this patch reduce to a single task context and a single CPU context but adds some intermediate data-structures: task_struct::perf_event_ctxp -> perf_event_context <- perf_cpu_context ^ | ^ ^ `---------------------------' | | | | perf_cpu_pmu_context <--. | `----. ^ | | | | | | v v | | ,--> perf_event_pmu_context | | | | | | | v v | perf_event ---> pmu ----------------' With the new design, perf_event_context will hold all events for all pmus in the (respective pinned/flexible) rbtrees. This can be achieved by adding pmu to rbtree key: {cpu, pmu, cgroup, group_index} Each perf_event_context carries a list of perf_event_pmu_context which is used to hold per-pmu-per-context state. For example, it keeps track of currently active events for that pmu, a pmu specific task_ctx_data, a flag to tell whether rotation is required or not etc. Additionally, perf_cpu_pmu_context is used to hold per-pmu-per-cpu state like hrtimer details to drive the event rotation, a pointer to perf_event_pmu_context of currently running task and some other ancillary information. Each perf_event is associated to it's pmu, perf_event_context and perf_event_pmu_context. Further optimizations to current implementation are possible. For example, ctx_resched() can be optimized to reschedule only single pmu events. Much thanks to Ravi for picking this up and pushing it towards completion. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Ravi Bangoria <ravi.bangoria@amd.com> Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20221008062424.313-1-ravi.bangoria@amd.com
2022-10-08 06:24:24 +00:00
struct perf_event_context *ctx;
int nr_user = 0;
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
perf: Rewrite core context handling There have been various issues and limitations with the way perf uses (task) contexts to track events. Most notable is the single hardware PMU task context, which has resulted in a number of yucky things (both proposed and merged). Notably: - HW breakpoint PMU - ARM big.little PMU / Intel ADL PMU - Intel Branch Monitoring PMU - AMD IBS PMU - S390 cpum_cf PMU - PowerPC trace_imc PMU *Current design:* Currently we have a per task and per cpu perf_event_contexts: task_struct::perf_events_ctxp[] <-> perf_event_context <-> perf_cpu_context ^ | ^ | ^ `---------------------------------' | `--> pmu ---' v ^ perf_event ------' Each task has an array of pointers to a perf_event_context. Each perf_event_context has a direct relation to a PMU and a group of events for that PMU. The task related perf_event_context's have a pointer back to that task. Each PMU has a per-cpu pointer to a per-cpu perf_cpu_context, which includes a perf_event_context, which again has a direct relation to that PMU, and a group of events for that PMU. The perf_cpu_context also tracks which task context is currently associated with that CPU and includes a few other things like the hrtimer for rotation etc. Each perf_event is then associated with its PMU and one perf_event_context. *Proposed design:* New design proposed by this patch reduce to a single task context and a single CPU context but adds some intermediate data-structures: task_struct::perf_event_ctxp -> perf_event_context <- perf_cpu_context ^ | ^ ^ `---------------------------' | | | | perf_cpu_pmu_context <--. | `----. ^ | | | | | | v v | | ,--> perf_event_pmu_context | | | | | | | v v | perf_event ---> pmu ----------------' With the new design, perf_event_context will hold all events for all pmus in the (respective pinned/flexible) rbtrees. This can be achieved by adding pmu to rbtree key: {cpu, pmu, cgroup, group_index} Each perf_event_context carries a list of perf_event_pmu_context which is used to hold per-pmu-per-context state. For example, it keeps track of currently active events for that pmu, a pmu specific task_ctx_data, a flag to tell whether rotation is required or not etc. Additionally, perf_cpu_pmu_context is used to hold per-pmu-per-cpu state like hrtimer details to drive the event rotation, a pointer to perf_event_pmu_context of currently running task and some other ancillary information. Each perf_event is associated to it's pmu, perf_event_context and perf_event_pmu_context. Further optimizations to current implementation are possible. For example, ctx_resched() can be optimized to reschedule only single pmu events. Much thanks to Ravi for picking this up and pushing it towards completion. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Ravi Bangoria <ravi.bangoria@amd.com> Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20221008062424.313-1-ravi.bangoria@amd.com
2022-10-08 06:24:24 +00:00
ctx = perf_cpu_task_ctx();
if (ctx)
nr_user = ctx->nr_user;
if (sysctl_perf_user_access && nr_user)
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
armv8pmu_enable_user_access(cpu_pmu);
else
armv8pmu_disable_user_access();
/* Enable all counters */
armv8pmu_pmcr_write(armv8pmu_pmcr_read() | ARMV8_PMU_PMCR_E);
kvm_vcpu_pmu_resync_el0();
}
static void armv8pmu_stop(struct arm_pmu *cpu_pmu)
{
/* Disable all counters */
armv8pmu_pmcr_write(armv8pmu_pmcr_read() & ~ARMV8_PMU_PMCR_E);
}
static irqreturn_t armv8pmu_handle_irq(struct arm_pmu *cpu_pmu)
{
u64 pmovsr;
struct perf_sample_data data;
struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
struct pt_regs *regs;
int idx;
/*
* Get and reset the IRQ flags
*/
pmovsr = armv8pmu_getreset_flags();
/*
* Did an overflow occur?
*/
if (!armv8pmu_has_overflowed(pmovsr))
return IRQ_NONE;
/*
* Handle the counter(s) overflow(s)
*/
regs = get_irq_regs();
/*
* Stop the PMU while processing the counter overflows
* to prevent skews in group events.
*/
armv8pmu_stop(cpu_pmu);
for_each_set_bit(idx, cpu_pmu->cntr_mask, ARMPMU_MAX_HWEVENTS) {
struct perf_event *event = cpuc->events[idx];
struct hw_perf_event *hwc;
/* Ignore if we don't have an event. */
if (!event)
continue;
/*
* We have a single interrupt for all counters. Check that
* each counter has overflowed before we process it.
*/
if (!armv8pmu_counter_has_overflowed(pmovsr, idx))
continue;
hwc = &event->hw;
armpmu_event_update(event);
perf_sample_data_init(&data, 0, hwc->last_period);
if (!armpmu_event_set_period(event))
continue;
2020-09-24 11:07:03 +00:00
/*
* Perf event overflow will queue the processing of the event as
* an irq_work which will be taken care of in the handling of
* IPI_IRQ_WORK.
*/
if (perf_event_overflow(event, &data, regs))
cpu_pmu->disable(event);
}
armv8pmu_start(cpu_pmu);
return IRQ_HANDLED;
}
static int armv8pmu_get_single_idx(struct pmu_hw_events *cpuc,
struct arm_pmu *cpu_pmu)
{
int idx;
for_each_set_bit(idx, cpu_pmu->cntr_mask, ARMV8_PMU_MAX_GENERAL_COUNTERS) {
if (!test_and_set_bit(idx, cpuc->used_mask))
return idx;
}
return -EAGAIN;
}
static int armv8pmu_get_chain_idx(struct pmu_hw_events *cpuc,
struct arm_pmu *cpu_pmu)
{
int idx;
/*
* Chaining requires two consecutive event counters, where
* the lower idx must be even.
*/
for_each_set_bit(idx, cpu_pmu->cntr_mask, ARMV8_PMU_MAX_GENERAL_COUNTERS) {
if (!(idx & 0x1))
continue;
if (!test_and_set_bit(idx, cpuc->used_mask)) {
/* Check if the preceding even counter is available */
if (!test_and_set_bit(idx - 1, cpuc->used_mask))
return idx;
/* Release the Odd counter */
clear_bit(idx, cpuc->used_mask);
}
}
return -EAGAIN;
}
static int armv8pmu_get_event_idx(struct pmu_hw_events *cpuc,
struct perf_event *event)
{
struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
struct hw_perf_event *hwc = &event->hw;
unsigned long evtype = hwc->config_base & ARMV8_PMU_EVTYPE_EVENT;
/* Always prefer to place a cycle counter into the cycle counter. */
if ((evtype == ARMV8_PMUV3_PERFCTR_CPU_CYCLES) &&
!armv8pmu_event_get_threshold(&event->attr)) {
if (!test_and_set_bit(ARMV8_PMU_CYCLE_IDX, cpuc->used_mask))
return ARMV8_PMU_CYCLE_IDX;
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
else if (armv8pmu_event_is_64bit(event) &&
armv8pmu_event_want_user_access(event) &&
!armv8pmu_has_long_event(cpu_pmu))
return -EAGAIN;
}
/*
* Always prefer to place a instruction counter into the instruction counter,
* but don't expose the instruction counter to userspace access as userspace
* may not know how to handle it.
*/
if ((evtype == ARMV8_PMUV3_PERFCTR_INST_RETIRED) &&
!armv8pmu_event_get_threshold(&event->attr) &&
test_bit(ARMV8_PMU_INSTR_IDX, cpu_pmu->cntr_mask) &&
!armv8pmu_event_want_user_access(event)) {
if (!test_and_set_bit(ARMV8_PMU_INSTR_IDX, cpuc->used_mask))
return ARMV8_PMU_INSTR_IDX;
}
/*
* Otherwise use events counters
*/
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
if (armv8pmu_event_is_chained(event))
return armv8pmu_get_chain_idx(cpuc, cpu_pmu);
else
return armv8pmu_get_single_idx(cpuc, cpu_pmu);
}
static void armv8pmu_clear_event_idx(struct pmu_hw_events *cpuc,
struct perf_event *event)
{
int idx = event->hw.idx;
clear_bit(idx, cpuc->used_mask);
if (armv8pmu_event_is_chained(event))
clear_bit(idx - 1, cpuc->used_mask);
}
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
static int armv8pmu_user_event_idx(struct perf_event *event)
{
if (!sysctl_perf_user_access || !armv8pmu_event_has_user_read(event))
return 0;
return event->hw.idx + 1;
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
}
/*
* Add an event filter to a given event.
*/
static int armv8pmu_set_event_filter(struct hw_perf_event *event,
struct perf_event_attr *attr)
{
unsigned long config_base = 0;
arm64: perf: Add support for event counting threshold FEAT_PMUv3_TH (Armv8.8) permits a PMU counter to increment only on events whose count meets a specified threshold condition. For example if PMEVTYPERn.TC (Threshold Control) is set to 0b101 (Greater than or equal, count), and the threshold is set to 2, then the PMU counter will now only increment by 1 when an event would have previously incremented the PMU counter by 2 or more on a single processor cycle. Three new Perf event config fields, 'threshold', 'threshold_compare' and 'threshold_count' have been added to control the feature. threshold_compare maps to the upper two bits of PMEVTYPERn.TC and threshold_count maps to the first bit of TC. These separate attributes have been picked rather than enumerating all the possible combinations of the TC field as in the Arm ARM. The attributes would be used on a Perf command line like this: $ perf stat -e stall_slot/threshold=2,threshold_compare=2/ A new capability for reading out the maximum supported threshold value has also been added: $ cat /sys/bus/event_source/devices/armv8_pmuv3/caps/threshold_max 0x000000ff If a threshold higher than threshold_max is provided, then an error is generated. If FEAT_PMUv3_TH isn't implemented or a 32 bit kernel is running, then threshold_max reads zero, and attempting to set a threshold value will also result in an error. The threshold is per PMU counter, and there are potentially different threshold_max values per PMU type on heterogeneous systems. Bits higher than 32 now need to be written into PMEVTYPER, so armv8pmu_write_evtype() has to be updated to take an unsigned long value rather than u32 which gives the correct behavior on both aarch32 and 64. Signed-off-by: James Clark <james.clark@arm.com> Link: https://lore.kernel.org/r/20231211161331.1277825-11-james.clark@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2023-12-11 16:13:22 +00:00
struct perf_event *perf_event = container_of(attr, struct perf_event,
attr);
struct arm_pmu *cpu_pmu = to_arm_pmu(perf_event->pmu);
u32 th;
if (attr->exclude_idle) {
pr_debug("ARM performance counters do not support mode exclusion\n");
return -EOPNOTSUPP;
}
/*
* If we're running in hyp mode, then we *are* the hypervisor.
* Therefore we ignore exclude_hv in this configuration, since
* there's no hypervisor to sample anyway. This is consistent
* with other architectures (x86 and Power).
*/
if (is_kernel_in_hyp_mode()) {
if (!attr->exclude_kernel && !attr->exclude_host)
config_base |= ARMV8_PMU_INCLUDE_EL2;
if (attr->exclude_guest)
config_base |= ARMV8_PMU_EXCLUDE_EL1;
if (attr->exclude_host)
config_base |= ARMV8_PMU_EXCLUDE_EL0;
} else {
if (!attr->exclude_hv && !attr->exclude_host)
config_base |= ARMV8_PMU_INCLUDE_EL2;
}
/*
* Filter out !VHE kernels and guest kernels
*/
if (attr->exclude_kernel)
config_base |= ARMV8_PMU_EXCLUDE_EL1;
if (attr->exclude_user)
config_base |= ARMV8_PMU_EXCLUDE_EL0;
arm64: perf: Add support for event counting threshold FEAT_PMUv3_TH (Armv8.8) permits a PMU counter to increment only on events whose count meets a specified threshold condition. For example if PMEVTYPERn.TC (Threshold Control) is set to 0b101 (Greater than or equal, count), and the threshold is set to 2, then the PMU counter will now only increment by 1 when an event would have previously incremented the PMU counter by 2 or more on a single processor cycle. Three new Perf event config fields, 'threshold', 'threshold_compare' and 'threshold_count' have been added to control the feature. threshold_compare maps to the upper two bits of PMEVTYPERn.TC and threshold_count maps to the first bit of TC. These separate attributes have been picked rather than enumerating all the possible combinations of the TC field as in the Arm ARM. The attributes would be used on a Perf command line like this: $ perf stat -e stall_slot/threshold=2,threshold_compare=2/ A new capability for reading out the maximum supported threshold value has also been added: $ cat /sys/bus/event_source/devices/armv8_pmuv3/caps/threshold_max 0x000000ff If a threshold higher than threshold_max is provided, then an error is generated. If FEAT_PMUv3_TH isn't implemented or a 32 bit kernel is running, then threshold_max reads zero, and attempting to set a threshold value will also result in an error. The threshold is per PMU counter, and there are potentially different threshold_max values per PMU type on heterogeneous systems. Bits higher than 32 now need to be written into PMEVTYPER, so armv8pmu_write_evtype() has to be updated to take an unsigned long value rather than u32 which gives the correct behavior on both aarch32 and 64. Signed-off-by: James Clark <james.clark@arm.com> Link: https://lore.kernel.org/r/20231211161331.1277825-11-james.clark@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2023-12-11 16:13:22 +00:00
/*
* If FEAT_PMUv3_TH isn't implemented, then THWIDTH (threshold_max) will
* be 0 and will also trigger this check, preventing it from being used.
*/
th = armv8pmu_event_get_threshold(attr);
arm64: perf: Add support for event counting threshold FEAT_PMUv3_TH (Armv8.8) permits a PMU counter to increment only on events whose count meets a specified threshold condition. For example if PMEVTYPERn.TC (Threshold Control) is set to 0b101 (Greater than or equal, count), and the threshold is set to 2, then the PMU counter will now only increment by 1 when an event would have previously incremented the PMU counter by 2 or more on a single processor cycle. Three new Perf event config fields, 'threshold', 'threshold_compare' and 'threshold_count' have been added to control the feature. threshold_compare maps to the upper two bits of PMEVTYPERn.TC and threshold_count maps to the first bit of TC. These separate attributes have been picked rather than enumerating all the possible combinations of the TC field as in the Arm ARM. The attributes would be used on a Perf command line like this: $ perf stat -e stall_slot/threshold=2,threshold_compare=2/ A new capability for reading out the maximum supported threshold value has also been added: $ cat /sys/bus/event_source/devices/armv8_pmuv3/caps/threshold_max 0x000000ff If a threshold higher than threshold_max is provided, then an error is generated. If FEAT_PMUv3_TH isn't implemented or a 32 bit kernel is running, then threshold_max reads zero, and attempting to set a threshold value will also result in an error. The threshold is per PMU counter, and there are potentially different threshold_max values per PMU type on heterogeneous systems. Bits higher than 32 now need to be written into PMEVTYPER, so armv8pmu_write_evtype() has to be updated to take an unsigned long value rather than u32 which gives the correct behavior on both aarch32 and 64. Signed-off-by: James Clark <james.clark@arm.com> Link: https://lore.kernel.org/r/20231211161331.1277825-11-james.clark@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2023-12-11 16:13:22 +00:00
if (th > threshold_max(cpu_pmu)) {
pr_debug("PMU event threshold exceeds max value\n");
return -EINVAL;
}
if (th) {
arm64: perf: Add support for event counting threshold FEAT_PMUv3_TH (Armv8.8) permits a PMU counter to increment only on events whose count meets a specified threshold condition. For example if PMEVTYPERn.TC (Threshold Control) is set to 0b101 (Greater than or equal, count), and the threshold is set to 2, then the PMU counter will now only increment by 1 when an event would have previously incremented the PMU counter by 2 or more on a single processor cycle. Three new Perf event config fields, 'threshold', 'threshold_compare' and 'threshold_count' have been added to control the feature. threshold_compare maps to the upper two bits of PMEVTYPERn.TC and threshold_count maps to the first bit of TC. These separate attributes have been picked rather than enumerating all the possible combinations of the TC field as in the Arm ARM. The attributes would be used on a Perf command line like this: $ perf stat -e stall_slot/threshold=2,threshold_compare=2/ A new capability for reading out the maximum supported threshold value has also been added: $ cat /sys/bus/event_source/devices/armv8_pmuv3/caps/threshold_max 0x000000ff If a threshold higher than threshold_max is provided, then an error is generated. If FEAT_PMUv3_TH isn't implemented or a 32 bit kernel is running, then threshold_max reads zero, and attempting to set a threshold value will also result in an error. The threshold is per PMU counter, and there are potentially different threshold_max values per PMU type on heterogeneous systems. Bits higher than 32 now need to be written into PMEVTYPER, so armv8pmu_write_evtype() has to be updated to take an unsigned long value rather than u32 which gives the correct behavior on both aarch32 and 64. Signed-off-by: James Clark <james.clark@arm.com> Link: https://lore.kernel.org/r/20231211161331.1277825-11-james.clark@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2023-12-11 16:13:22 +00:00
config_base |= FIELD_PREP(ARMV8_PMU_EVTYPE_TH, th);
config_base |= FIELD_PREP(ARMV8_PMU_EVTYPE_TC,
armv8pmu_event_threshold_control(attr));
}
/*
* Install the filter into config_base as this is used to
* construct the event type.
*/
event->config_base = config_base;
return 0;
}
static void armv8pmu_reset(void *info)
{
struct arm_pmu *cpu_pmu = (struct arm_pmu *)info;
u64 pmcr, mask;
bitmap_to_arr64(&mask, cpu_pmu->cntr_mask, ARMPMU_MAX_HWEVENTS);
/* The counter and interrupt enable registers are unknown at reset. */
armv8pmu_disable_counter(mask);
armv8pmu_disable_intens(mask);
/* Clear the counters we flip at guest entry/exit */
kvm_clr_pmu_events(mask);
/*
* Initialize & Reset PMNC. Request overflow interrupt for
* 64 bit cycle counter but cheat in armv8pmu_write_counter().
*/
pmcr = ARMV8_PMU_PMCR_P | ARMV8_PMU_PMCR_C | ARMV8_PMU_PMCR_LC;
/* Enable long event counter support where available */
if (armv8pmu_has_long_event(cpu_pmu))
pmcr |= ARMV8_PMU_PMCR_LP;
armv8pmu_pmcr_write(pmcr);
}
static int __armv8_pmuv3_map_event_id(struct arm_pmu *armpmu,
struct perf_event *event)
{
if (event->attr.type == PERF_TYPE_HARDWARE &&
event->attr.config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS) {
if (test_bit(ARMV8_PMUV3_PERFCTR_BR_RETIRED,
armpmu->pmceid_bitmap))
return ARMV8_PMUV3_PERFCTR_BR_RETIRED;
if (test_bit(ARMV8_PMUV3_PERFCTR_PC_WRITE_RETIRED,
armpmu->pmceid_bitmap))
return ARMV8_PMUV3_PERFCTR_PC_WRITE_RETIRED;
return HW_OP_UNSUPPORTED;
}
return armpmu_map_event(event, &armv8_pmuv3_perf_map,
&armv8_pmuv3_perf_cache_map,
ARMV8_PMU_EVTYPE_EVENT);
}
static int __armv8_pmuv3_map_event(struct perf_event *event,
const unsigned (*extra_event_map)
[PERF_COUNT_HW_MAX],
const unsigned (*extra_cache_map)
[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX])
{
int hw_event_id;
struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
hw_event_id = __armv8_pmuv3_map_event_id(armpmu, event);
arm64: perf: reject CHAIN events at creation time Currently it's possible for a user to open CHAIN events arbitrarily, which we previously tried to rule out in commit: ca2b497253ad01c8 ("arm64: perf: Reject stand-alone CHAIN events for PMUv3") Which allowed the events to be opened, but prevented them from being scheduled by by using an arm_pmu::filter_match hook to reject the relevant events. The CHAIN event filtering in the arm_pmu::filter_match hook was silently removed in commit: bd27568117664b8b ("perf: Rewrite core context handling") As a result, it's now possible for users to open CHAIN events, and for these to be installed arbitrarily. Fix this by rejecting CHAIN events at creation time. This avoids the creation of events which will never count, and doesn't require using the dynamic filtering. Attempting to open a CHAIN event (0x1e) will now be rejected: | # ./perf stat -e armv8_pmuv3/config=0x1e/ ls | perf | | Performance counter stats for 'ls': | | <not supported> armv8_pmuv3/config=0x1e/ | | 0.002197470 seconds time elapsed | | 0.000000000 seconds user | 0.002294000 seconds sys Other events (e.g. CPU_CYCLES / 0x11) will open as usual: | # ./perf stat -e armv8_pmuv3/config=0x11/ ls | perf | | Performance counter stats for 'ls': | | 2538761 armv8_pmuv3/config=0x11/ | | 0.002227330 seconds time elapsed | | 0.002369000 seconds user | 0.000000000 seconds sys Fixes: bd2756811766 ("perf: Rewrite core context handling") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230216141240.3833272-3-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2023-02-16 14:12:39 +00:00
/*
* CHAIN events only work when paired with an adjacent counter, and it
* never makes sense for a user to open one in isolation, as they'll be
* rotated arbitrarily.
*/
if (hw_event_id == ARMV8_PMUV3_PERFCTR_CHAIN)
return -EINVAL;
if (armv8pmu_event_is_64bit(event))
event->hw.flags |= ARMPMU_EVT_64BIT;
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
/*
* User events must be allocated into a single counter, and so
* must not be chained.
*
* Most 64-bit events require long counter support, but 64-bit
* CPU_CYCLES events can be placed into the dedicated cycle
* counter when this is free.
*/
if (armv8pmu_event_want_user_access(event)) {
if (!(event->attach_state & PERF_ATTACH_TASK))
return -EINVAL;
if (armv8pmu_event_is_64bit(event) &&
(hw_event_id != ARMV8_PMUV3_PERFCTR_CPU_CYCLES) &&
!armv8pmu_has_long_event(armpmu))
return -EOPNOTSUPP;
event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT;
}
/* Only expose micro/arch events supported by this PMU */
if ((hw_event_id > 0) && (hw_event_id < ARMV8_PMUV3_MAX_COMMON_EVENTS)
&& test_bit(hw_event_id, armpmu->pmceid_bitmap)) {
return hw_event_id;
}
return armpmu_map_event(event, extra_event_map, extra_cache_map,
ARMV8_PMU_EVTYPE_EVENT);
}
static int armv8_pmuv3_map_event(struct perf_event *event)
{
return __armv8_pmuv3_map_event(event, NULL, NULL);
}
static int armv8_a53_map_event(struct perf_event *event)
{
return __armv8_pmuv3_map_event(event, NULL, &armv8_a53_perf_cache_map);
}
static int armv8_a57_map_event(struct perf_event *event)
{
return __armv8_pmuv3_map_event(event, NULL, &armv8_a57_perf_cache_map);
}
static int armv8_a73_map_event(struct perf_event *event)
{
return __armv8_pmuv3_map_event(event, NULL, &armv8_a73_perf_cache_map);
}
static int armv8_thunder_map_event(struct perf_event *event)
{
return __armv8_pmuv3_map_event(event, NULL,
&armv8_thunder_perf_cache_map);
}
static int armv8_vulcan_map_event(struct perf_event *event)
{
return __armv8_pmuv3_map_event(event, NULL,
&armv8_vulcan_perf_cache_map);
}
struct armv8pmu_probe_info {
struct arm_pmu *pmu;
bool present;
};
static void __armv8pmu_probe_pmu(void *info)
{
struct armv8pmu_probe_info *probe = info;
struct arm_pmu *cpu_pmu = probe->pmu;
u64 pmceid_raw[2];
u32 pmceid[2];
int pmuver;
pmuver = read_pmuver();
if (!pmuv3_implemented(pmuver))
return;
cpu_pmu->pmuver = pmuver;
probe->present = true;
/* Read the nb of CNTx counters supported from PMNC */
bitmap_set(cpu_pmu->cntr_mask,
0, FIELD_GET(ARMV8_PMU_PMCR_N, armv8pmu_pmcr_read()));
/* Add the CPU cycles counter */
set_bit(ARMV8_PMU_CYCLE_IDX, cpu_pmu->cntr_mask);
/* Add the CPU instructions counter */
if (pmuv3_has_icntr())
set_bit(ARMV8_PMU_INSTR_IDX, cpu_pmu->cntr_mask);
pmceid[0] = pmceid_raw[0] = read_pmceid0();
pmceid[1] = pmceid_raw[1] = read_pmceid1();
bitmap_from_arr32(cpu_pmu->pmceid_bitmap,
pmceid, ARMV8_PMUV3_MAX_COMMON_EVENTS);
pmceid[0] = pmceid_raw[0] >> 32;
pmceid[1] = pmceid_raw[1] >> 32;
bitmap_from_arr32(cpu_pmu->pmceid_ext_bitmap,
pmceid, ARMV8_PMUV3_MAX_COMMON_EVENTS);
/* store PMMIR register for sysfs */
2023-10-13 02:43:54 +00:00
if (is_pmuv3p4(pmuver))
cpu_pmu->reg_pmmir = read_pmmir();
else
cpu_pmu->reg_pmmir = 0;
}
static int armv8pmu_probe_pmu(struct arm_pmu *cpu_pmu)
{
struct armv8pmu_probe_info probe = {
.pmu = cpu_pmu,
.present = false,
};
int ret;
ret = smp_call_function_any(&cpu_pmu->supported_cpus,
__armv8pmu_probe_pmu,
&probe, 1);
if (ret)
return ret;
return probe.present ? 0 : -ENODEV;
}
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
static void armv8pmu_disable_user_access_ipi(void *unused)
{
armv8pmu_disable_user_access();
}
sysctl: treewide: constify the ctl_table argument of proc_handlers const qualify the struct ctl_table argument in the proc_handler function signatures. This is a prerequisite to moving the static ctl_table structs into .rodata data which will ensure that proc_handler function pointers cannot be modified. This patch has been generated by the following coccinelle script: ``` virtual patch @r1@ identifier ctl, write, buffer, lenp, ppos; identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)"; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int write, void *buffer, size_t *lenp, loff_t *ppos); @r2@ identifier func, ctl, write, buffer, lenp, ppos; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int write, void *buffer, size_t *lenp, loff_t *ppos) { ... } @r3@ identifier func; @@ int func( - struct ctl_table * + const struct ctl_table * ,int , void *, size_t *, loff_t *); @r4@ identifier func, ctl; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int , void *, size_t *, loff_t *); @r5@ identifier func, write, buffer, lenp, ppos; @@ int func( - struct ctl_table * + const struct ctl_table * ,int write, void *buffer, size_t *lenp, loff_t *ppos); ``` * Code formatting was adjusted in xfs_sysctl.c to comply with code conventions. The xfs_stats_clear_proc_handler, xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where adjusted. * The ctl_table argument in proc_watchdog_common was const qualified. This is called from a proc_handler itself and is calling back into another proc_handler, making it necessary to change it as part of the proc_handler migration. Co-developed-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Co-developed-by: Joel Granados <j.granados@samsung.com> Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-07-24 18:59:29 +00:00
static int armv8pmu_proc_user_access_handler(const struct ctl_table *table, int write,
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
void *buffer, size_t *lenp, loff_t *ppos)
{
int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
if (ret || !write || sysctl_perf_user_access)
return ret;
on_each_cpu(armv8pmu_disable_user_access_ipi, NULL, 1);
return 0;
}
static struct ctl_table armv8_pmu_sysctl_table[] = {
{
.procname = "perf_user_access",
.data = &sysctl_perf_user_access,
.maxlen = sizeof(unsigned int),
.mode = 0644,
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
.proc_handler = armv8pmu_proc_user_access_handler,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
};
arm64: perf: Don't register user access sysctl handler multiple times Commit e2012600810c ("arm64: perf: Add userspace counter access disable switch") introduced a new 'perf_user_access' sysctl file to enable and disable direct userspace access to the PMU counters. Sadly, Geert reports that on his big.LITTLE SoC ('Renesas Salvator-XS w/ R-Car H3'), the file is created for each PMU type probed, resulting in a splat during boot: | hw perfevents: enabled with armv8_cortex_a53 PMU driver, 7 counters available | sysctl duplicate entry: /kernel//perf_user_access | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.16.0-rc3-arm64-renesas-00003-ge2012600810c #1420 | Hardware name: Renesas Salvator-X 2nd version board based on r8a77951 (DT) | Call trace: | dump_backtrace+0x0/0x190 | show_stack+0x14/0x20 | dump_stack_lvl+0x88/0xb0 | dump_stack+0x14/0x2c | __register_sysctl_table+0x384/0x818 | register_sysctl+0x20/0x28 | armv8_pmu_init.constprop.0+0x118/0x150 | armv8_a57_pmu_init+0x1c/0x28 | arm_pmu_device_probe+0x1b4/0x558 | armv8_pmu_device_probe+0x18/0x20 | platform_probe+0x64/0xd0 | hw perfevents: enabled with armv8_cortex_a57 PMU driver, 7 counters available Introduce a state variable to track creation of the sysctl file and ensure that it is only created once. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Fixes: e2012600810c ("arm64: perf: Add userspace counter access disable switch") Link: https://lore.kernel.org/r/CAMuHMdVcDxR9sGzc5pcnORiotonERBgc6dsXZXMd6wTvLGA9iw@mail.gmail.com Signed-off-by: Will Deacon <will@kernel.org>
2022-01-04 14:57:14 +00:00
static void armv8_pmu_register_sysctl_table(void)
{
static u32 tbl_registered = 0;
if (!cmpxchg_relaxed(&tbl_registered, 0, 1))
register_sysctl("kernel", armv8_pmu_sysctl_table);
}
static int armv8_pmu_init(struct arm_pmu *cpu_pmu, char *name,
int (*map_event)(struct perf_event *event))
{
int ret = armv8pmu_probe_pmu(cpu_pmu);
if (ret)
return ret;
cpu_pmu->handle_irq = armv8pmu_handle_irq;
cpu_pmu->enable = armv8pmu_enable_event;
cpu_pmu->disable = armv8pmu_disable_event;
cpu_pmu->read_counter = armv8pmu_read_counter;
cpu_pmu->write_counter = armv8pmu_write_counter;
cpu_pmu->get_event_idx = armv8pmu_get_event_idx;
cpu_pmu->clear_event_idx = armv8pmu_clear_event_idx;
cpu_pmu->start = armv8pmu_start;
cpu_pmu->stop = armv8pmu_stop;
cpu_pmu->reset = armv8pmu_reset;
cpu_pmu->set_event_filter = armv8pmu_set_event_filter;
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
cpu_pmu->pmu.event_idx = armv8pmu_user_event_idx;
cpu_pmu->name = name;
cpu_pmu->map_event = map_event;
cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_EVENTS] = &armv8_pmuv3_events_attr_group;
cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_FORMATS] = &armv8_pmuv3_format_attr_group;
cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_CAPS] = &armv8_pmuv3_caps_attr_group;
arm64: perf: Don't register user access sysctl handler multiple times Commit e2012600810c ("arm64: perf: Add userspace counter access disable switch") introduced a new 'perf_user_access' sysctl file to enable and disable direct userspace access to the PMU counters. Sadly, Geert reports that on his big.LITTLE SoC ('Renesas Salvator-XS w/ R-Car H3'), the file is created for each PMU type probed, resulting in a splat during boot: | hw perfevents: enabled with armv8_cortex_a53 PMU driver, 7 counters available | sysctl duplicate entry: /kernel//perf_user_access | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.16.0-rc3-arm64-renesas-00003-ge2012600810c #1420 | Hardware name: Renesas Salvator-X 2nd version board based on r8a77951 (DT) | Call trace: | dump_backtrace+0x0/0x190 | show_stack+0x14/0x20 | dump_stack_lvl+0x88/0xb0 | dump_stack+0x14/0x2c | __register_sysctl_table+0x384/0x818 | register_sysctl+0x20/0x28 | armv8_pmu_init.constprop.0+0x118/0x150 | armv8_a57_pmu_init+0x1c/0x28 | arm_pmu_device_probe+0x1b4/0x558 | armv8_pmu_device_probe+0x18/0x20 | platform_probe+0x64/0xd0 | hw perfevents: enabled with armv8_cortex_a57 PMU driver, 7 counters available Introduce a state variable to track creation of the sysctl file and ensure that it is only created once. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Fixes: e2012600810c ("arm64: perf: Add userspace counter access disable switch") Link: https://lore.kernel.org/r/CAMuHMdVcDxR9sGzc5pcnORiotonERBgc6dsXZXMd6wTvLGA9iw@mail.gmail.com Signed-off-by: Will Deacon <will@kernel.org>
2022-01-04 14:57:14 +00:00
armv8_pmu_register_sysctl_table();
return 0;
}
#define PMUV3_INIT_SIMPLE(name) \
static int name##_pmu_init(struct arm_pmu *cpu_pmu) \
{ \
return armv8_pmu_init(cpu_pmu, #name, armv8_pmuv3_map_event); \
}
#define PMUV3_INIT_MAP_EVENT(name, map_event) \
static int name##_pmu_init(struct arm_pmu *cpu_pmu) \
{ \
return armv8_pmu_init(cpu_pmu, #name, map_event); \
}
PMUV3_INIT_SIMPLE(armv8_pmuv3)
PMUV3_INIT_SIMPLE(armv8_cortex_a34)
PMUV3_INIT_SIMPLE(armv8_cortex_a55)
PMUV3_INIT_SIMPLE(armv8_cortex_a65)
PMUV3_INIT_SIMPLE(armv8_cortex_a75)
PMUV3_INIT_SIMPLE(armv8_cortex_a76)
PMUV3_INIT_SIMPLE(armv8_cortex_a77)
PMUV3_INIT_SIMPLE(armv8_cortex_a78)
PMUV3_INIT_SIMPLE(armv9_cortex_a510)
PMUV3_INIT_SIMPLE(armv9_cortex_a520)
PMUV3_INIT_SIMPLE(armv9_cortex_a710)
PMUV3_INIT_SIMPLE(armv9_cortex_a715)
PMUV3_INIT_SIMPLE(armv9_cortex_a720)
PMUV3_INIT_SIMPLE(armv9_cortex_a725)
PMUV3_INIT_SIMPLE(armv8_cortex_x1)
PMUV3_INIT_SIMPLE(armv9_cortex_x2)
PMUV3_INIT_SIMPLE(armv9_cortex_x3)
PMUV3_INIT_SIMPLE(armv9_cortex_x4)
PMUV3_INIT_SIMPLE(armv9_cortex_x925)
PMUV3_INIT_SIMPLE(armv8_neoverse_e1)
PMUV3_INIT_SIMPLE(armv8_neoverse_n1)
PMUV3_INIT_SIMPLE(armv9_neoverse_n2)
PMUV3_INIT_SIMPLE(armv9_neoverse_n3)
PMUV3_INIT_SIMPLE(armv8_neoverse_v1)
PMUV3_INIT_SIMPLE(armv8_neoverse_v2)
PMUV3_INIT_SIMPLE(armv8_neoverse_v3)
PMUV3_INIT_SIMPLE(armv8_neoverse_v3ae)
PMUV3_INIT_SIMPLE(armv8_nvidia_carmel)
PMUV3_INIT_SIMPLE(armv8_nvidia_denver)
PMUV3_INIT_SIMPLE(armv8_samsung_mongoose)
PMUV3_INIT_MAP_EVENT(armv8_cortex_a35, armv8_a53_map_event)
PMUV3_INIT_MAP_EVENT(armv8_cortex_a53, armv8_a53_map_event)
PMUV3_INIT_MAP_EVENT(armv8_cortex_a57, armv8_a57_map_event)
PMUV3_INIT_MAP_EVENT(armv8_cortex_a72, armv8_a57_map_event)
PMUV3_INIT_MAP_EVENT(armv8_cortex_a73, armv8_a73_map_event)
PMUV3_INIT_MAP_EVENT(armv8_cavium_thunder, armv8_thunder_map_event)
PMUV3_INIT_MAP_EVENT(armv8_brcm_vulcan, armv8_vulcan_map_event)
static const struct of_device_id armv8_pmu_of_device_ids[] = {
{.compatible = "arm,armv8-pmuv3", .data = armv8_pmuv3_pmu_init},
{.compatible = "arm,cortex-a34-pmu", .data = armv8_cortex_a34_pmu_init},
{.compatible = "arm,cortex-a35-pmu", .data = armv8_cortex_a35_pmu_init},
{.compatible = "arm,cortex-a53-pmu", .data = armv8_cortex_a53_pmu_init},
{.compatible = "arm,cortex-a55-pmu", .data = armv8_cortex_a55_pmu_init},
{.compatible = "arm,cortex-a57-pmu", .data = armv8_cortex_a57_pmu_init},
{.compatible = "arm,cortex-a65-pmu", .data = armv8_cortex_a65_pmu_init},
{.compatible = "arm,cortex-a72-pmu", .data = armv8_cortex_a72_pmu_init},
{.compatible = "arm,cortex-a73-pmu", .data = armv8_cortex_a73_pmu_init},
{.compatible = "arm,cortex-a75-pmu", .data = armv8_cortex_a75_pmu_init},
{.compatible = "arm,cortex-a76-pmu", .data = armv8_cortex_a76_pmu_init},
{.compatible = "arm,cortex-a77-pmu", .data = armv8_cortex_a77_pmu_init},
{.compatible = "arm,cortex-a78-pmu", .data = armv8_cortex_a78_pmu_init},
{.compatible = "arm,cortex-a510-pmu", .data = armv9_cortex_a510_pmu_init},
{.compatible = "arm,cortex-a520-pmu", .data = armv9_cortex_a520_pmu_init},
{.compatible = "arm,cortex-a710-pmu", .data = armv9_cortex_a710_pmu_init},
{.compatible = "arm,cortex-a715-pmu", .data = armv9_cortex_a715_pmu_init},
{.compatible = "arm,cortex-a720-pmu", .data = armv9_cortex_a720_pmu_init},
{.compatible = "arm,cortex-a725-pmu", .data = armv9_cortex_a725_pmu_init},
{.compatible = "arm,cortex-x1-pmu", .data = armv8_cortex_x1_pmu_init},
{.compatible = "arm,cortex-x2-pmu", .data = armv9_cortex_x2_pmu_init},
{.compatible = "arm,cortex-x3-pmu", .data = armv9_cortex_x3_pmu_init},
{.compatible = "arm,cortex-x4-pmu", .data = armv9_cortex_x4_pmu_init},
{.compatible = "arm,cortex-x925-pmu", .data = armv9_cortex_x925_pmu_init},
{.compatible = "arm,neoverse-e1-pmu", .data = armv8_neoverse_e1_pmu_init},
{.compatible = "arm,neoverse-n1-pmu", .data = armv8_neoverse_n1_pmu_init},
{.compatible = "arm,neoverse-n2-pmu", .data = armv9_neoverse_n2_pmu_init},
{.compatible = "arm,neoverse-n3-pmu", .data = armv9_neoverse_n3_pmu_init},
{.compatible = "arm,neoverse-v1-pmu", .data = armv8_neoverse_v1_pmu_init},
{.compatible = "arm,neoverse-v2-pmu", .data = armv8_neoverse_v2_pmu_init},
{.compatible = "arm,neoverse-v3-pmu", .data = armv8_neoverse_v3_pmu_init},
{.compatible = "arm,neoverse-v3ae-pmu", .data = armv8_neoverse_v3ae_pmu_init},
{.compatible = "cavium,thunder-pmu", .data = armv8_cavium_thunder_pmu_init},
{.compatible = "brcm,vulcan-pmu", .data = armv8_brcm_vulcan_pmu_init},
{.compatible = "nvidia,carmel-pmu", .data = armv8_nvidia_carmel_pmu_init},
{.compatible = "nvidia,denver-pmu", .data = armv8_nvidia_denver_pmu_init},
{.compatible = "samsung,mongoose-pmu", .data = armv8_samsung_mongoose_pmu_init},
{},
};
static int armv8_pmu_device_probe(struct platform_device *pdev)
{
return arm_pmu_device_probe(pdev, armv8_pmu_of_device_ids, NULL);
}
static struct platform_driver armv8_pmu_driver = {
.driver = {
.name = ARMV8_PMU_PDEV_NAME,
.of_match_table = armv8_pmu_of_device_ids,
arm64: perf: set suppress_bind_attrs flag to true The armv8_pmuv3 driver doesn't have a remove function, and when the test 'CONFIG_DEBUG_TEST_DRIVER_REMOVE=y' is enabled, the following Call trace can be seen. [ 1.424287] Failed to register pmu: armv8_pmuv3, reason -17 [ 1.424870] WARNING: CPU: 0 PID: 1 at ../kernel/events/core.c:11771 perf_event_sysfs_init+0x98/0xdc [ 1.425220] Modules linked in: [ 1.425531] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 4.19.0-rc7-next-20181012-00003-ge7a97b1ad77b-dirty #35 [ 1.425951] Hardware name: linux,dummy-virt (DT) [ 1.426212] pstate: 80000005 (Nzcv daif -PAN -UAO) [ 1.426458] pc : perf_event_sysfs_init+0x98/0xdc [ 1.426720] lr : perf_event_sysfs_init+0x98/0xdc [ 1.426908] sp : ffff00000804bd50 [ 1.427077] x29: ffff00000804bd50 x28: ffff00000934e078 [ 1.427429] x27: ffff000009546000 x26: 0000000000000007 [ 1.427757] x25: ffff000009280710 x24: 00000000ffffffef [ 1.428086] x23: ffff000009408000 x22: 0000000000000000 [ 1.428415] x21: ffff000009136008 x20: ffff000009408730 [ 1.428744] x19: ffff80007b20b400 x18: 000000000000000a [ 1.429075] x17: 0000000000000000 x16: 0000000000000000 [ 1.429418] x15: 0000000000000400 x14: 2e79726f74636572 [ 1.429748] x13: 696420656d617320 x12: 656874206e692065 [ 1.430060] x11: 6d616e20656d6173 x10: 2065687420687469 [ 1.430335] x9 : ffff00000804bd50 x8 : 206e6f7361657220 [ 1.430610] x7 : 2c3376756d705f38 x6 : ffff00000954d7ce [ 1.430880] x5 : 0000000000000000 x4 : 0000000000000000 [ 1.431226] x3 : 0000000000000000 x2 : ffffffffffffffff [ 1.431554] x1 : 4d151327adc50b00 x0 : 0000000000000000 [ 1.431868] Call trace: [ 1.432102] perf_event_sysfs_init+0x98/0xdc [ 1.432382] do_one_initcall+0x6c/0x1a8 [ 1.432637] kernel_init_freeable+0x1bc/0x280 [ 1.432905] kernel_init+0x18/0x160 [ 1.433115] ret_from_fork+0x10/0x18 [ 1.433297] ---[ end trace 27fd415390eb9883 ]--- Rework to set suppress_bind_attrs flag to avoid removing the device when CONFIG_DEBUG_TEST_DRIVER_REMOVE=y, since there's no real reason to remove the armv8_pmuv3 driver. Cc: Arnd Bergmann <arnd@arndb.de> Co-developed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-10-17 15:26:22 +00:00
.suppress_bind_attrs = true,
},
.probe = armv8_pmu_device_probe,
};
static int __init armv8_pmu_driver_init(void)
{
arm64: enable perf events based hard lockup detector With the recent feature added to enable perf events to use pseudo NMIs as interrupts on platforms which support GICv3 or later, its now been possible to enable hard lockup detector (or NMI watchdog) on arm64 platforms. So enable corresponding support. One thing to note here is that normally lockup detector is initialized just after the early initcalls but PMU on arm64 comes up much later as device_initcall(). To cope with that, override arch_perf_nmi_is_available() to let the watchdog framework know PMU not ready, and inform the framework to re-initialize lockup detection once PMU has been initialized. [dianders@chromium.org: only HAVE_HARDLOCKUP_DETECTOR_PERF if the PMU config is enabled] Link: https://lkml.kernel.org/r/20230523073952.1.I60217a63acc35621e13f10be16c0cd7c363caf8c@changeid Link: https://lkml.kernel.org/r/20230519101840.v5.18.Ia44852044cdcb074f387e80df6b45e892965d4a1@changeid Co-developed-by: Sumit Garg <sumit.garg@linaro.org> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Co-developed-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Colin Cross <ccross@android.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guenter Roeck <groeck@chromium.org> Cc: Ian Rogers <irogers@google.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Tzung-Bi Shih <tzungbi@chromium.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-05-19 17:18:42 +00:00
int ret;
if (acpi_disabled)
arm64: enable perf events based hard lockup detector With the recent feature added to enable perf events to use pseudo NMIs as interrupts on platforms which support GICv3 or later, its now been possible to enable hard lockup detector (or NMI watchdog) on arm64 platforms. So enable corresponding support. One thing to note here is that normally lockup detector is initialized just after the early initcalls but PMU on arm64 comes up much later as device_initcall(). To cope with that, override arch_perf_nmi_is_available() to let the watchdog framework know PMU not ready, and inform the framework to re-initialize lockup detection once PMU has been initialized. [dianders@chromium.org: only HAVE_HARDLOCKUP_DETECTOR_PERF if the PMU config is enabled] Link: https://lkml.kernel.org/r/20230523073952.1.I60217a63acc35621e13f10be16c0cd7c363caf8c@changeid Link: https://lkml.kernel.org/r/20230519101840.v5.18.Ia44852044cdcb074f387e80df6b45e892965d4a1@changeid Co-developed-by: Sumit Garg <sumit.garg@linaro.org> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Co-developed-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Colin Cross <ccross@android.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guenter Roeck <groeck@chromium.org> Cc: Ian Rogers <irogers@google.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Tzung-Bi Shih <tzungbi@chromium.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-05-19 17:18:42 +00:00
ret = platform_driver_register(&armv8_pmu_driver);
else
arm64: enable perf events based hard lockup detector With the recent feature added to enable perf events to use pseudo NMIs as interrupts on platforms which support GICv3 or later, its now been possible to enable hard lockup detector (or NMI watchdog) on arm64 platforms. So enable corresponding support. One thing to note here is that normally lockup detector is initialized just after the early initcalls but PMU on arm64 comes up much later as device_initcall(). To cope with that, override arch_perf_nmi_is_available() to let the watchdog framework know PMU not ready, and inform the framework to re-initialize lockup detection once PMU has been initialized. [dianders@chromium.org: only HAVE_HARDLOCKUP_DETECTOR_PERF if the PMU config is enabled] Link: https://lkml.kernel.org/r/20230523073952.1.I60217a63acc35621e13f10be16c0cd7c363caf8c@changeid Link: https://lkml.kernel.org/r/20230519101840.v5.18.Ia44852044cdcb074f387e80df6b45e892965d4a1@changeid Co-developed-by: Sumit Garg <sumit.garg@linaro.org> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Co-developed-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Colin Cross <ccross@android.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guenter Roeck <groeck@chromium.org> Cc: Ian Rogers <irogers@google.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Tzung-Bi Shih <tzungbi@chromium.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-05-19 17:18:42 +00:00
ret = arm_pmu_acpi_probe(armv8_pmuv3_pmu_init);
if (!ret)
lockup_detector_retry_init();
return ret;
}
device_initcall(armv8_pmu_driver_init)
arm64: perf: Add cap_user_time aarch64 It is useful to get the running time of a thread. Doing so in an efficient manner can be important for performance of user applications. Avoiding system calls in `clock_gettime` when handling CLOCK_THREAD_CPUTIME_ID is important. Other clocks are handled in the VDSO, but CLOCK_THREAD_CPUTIME_ID falls back on the system call. CLOCK_THREAD_CPUTIME_ID is not handled in the VDSO since it would have costs associated with maintaining updated user space accessible time offsets. These offsets have to be updated everytime the a thread is scheduled/descheduled. However, for programs regularly checking the running time of a thread, this is a performance improvement. This patch takes a middle ground, and adds support for cap_user_time an optional feature of the perf_event API. This way costs are only incurred when the perf_event api is enabled. This is done the same way as it is in x86. Ultimately this allows calculating the thread running time in userspace on aarch64 as follows (adapted from perf_event_open manpage): u32 seq, time_mult, time_shift; u64 running, count, time_offset, quot, rem, delta; struct perf_event_mmap_page *pc; pc = buf; // buf is the perf event mmaped page as documented in the API. if (pc->cap_usr_time) { do { seq = pc->lock; barrier(); running = pc->time_running; count = readCNTVCT_EL0(); // Read ARM hardware clock. time_offset = pc->time_offset; time_mult = pc->time_mult; time_shift = pc->time_shift; barrier(); } while (pc->lock != seq); quot = (count >> time_shift); rem = count & (((u64)1 << time_shift) - 1); delta = time_offset + quot * time_mult + ((rem * time_mult) >> time_shift); running += delta; // running now has the current nanosecond level thread time. } Summary of changes in the patch: For aarch64 systems, make arch_perf_update_userpage update the timing information stored in the perf_event page. Requiring the following calculations: - Calculate the appropriate time_mult, and time_shift factors to convert ticks to nano seconds for the current clock frequency. - Adjust the mult and shift factors to avoid shift factors of 32 bits. (possibly unnecessary) - The time_offset userspace should apply when doing calculations: negative the current sched time (now), because time_running and time_enabled fields of the perf_event page have just been updated. Toggle bits to appropriate values: - Enable cap_user_time Signed-off-by: Michael O'Farrell <micpof@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-30 20:14:34 +00:00
void arch_perf_update_userpage(struct perf_event *event,
struct perf_event_mmap_page *userpg, u64 now)
{
struct clock_read_data *rd;
unsigned int seq;
u64 ns;
arm64: perf: Add cap_user_time aarch64 It is useful to get the running time of a thread. Doing so in an efficient manner can be important for performance of user applications. Avoiding system calls in `clock_gettime` when handling CLOCK_THREAD_CPUTIME_ID is important. Other clocks are handled in the VDSO, but CLOCK_THREAD_CPUTIME_ID falls back on the system call. CLOCK_THREAD_CPUTIME_ID is not handled in the VDSO since it would have costs associated with maintaining updated user space accessible time offsets. These offsets have to be updated everytime the a thread is scheduled/descheduled. However, for programs regularly checking the running time of a thread, this is a performance improvement. This patch takes a middle ground, and adds support for cap_user_time an optional feature of the perf_event API. This way costs are only incurred when the perf_event api is enabled. This is done the same way as it is in x86. Ultimately this allows calculating the thread running time in userspace on aarch64 as follows (adapted from perf_event_open manpage): u32 seq, time_mult, time_shift; u64 running, count, time_offset, quot, rem, delta; struct perf_event_mmap_page *pc; pc = buf; // buf is the perf event mmaped page as documented in the API. if (pc->cap_usr_time) { do { seq = pc->lock; barrier(); running = pc->time_running; count = readCNTVCT_EL0(); // Read ARM hardware clock. time_offset = pc->time_offset; time_mult = pc->time_mult; time_shift = pc->time_shift; barrier(); } while (pc->lock != seq); quot = (count >> time_shift); rem = count & (((u64)1 << time_shift) - 1); delta = time_offset + quot * time_mult + ((rem * time_mult) >> time_shift); running += delta; // running now has the current nanosecond level thread time. } Summary of changes in the patch: For aarch64 systems, make arch_perf_update_userpage update the timing information stored in the perf_event page. Requiring the following calculations: - Calculate the appropriate time_mult, and time_shift factors to convert ticks to nano seconds for the current clock frequency. - Adjust the mult and shift factors to avoid shift factors of 32 bits. (possibly unnecessary) - The time_offset userspace should apply when doing calculations: negative the current sched time (now), because time_running and time_enabled fields of the perf_event page have just been updated. Toggle bits to appropriate values: - Enable cap_user_time Signed-off-by: Michael O'Farrell <micpof@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-30 20:14:34 +00:00
userpg->cap_user_time = 0;
userpg->cap_user_time_zero = 0;
userpg->cap_user_time_short = 0;
arm64: perf: Enable PMU counter userspace access for perf event Arm PMUs can support direct userspace access of counters which allows for low overhead (i.e. no syscall) self-monitoring of tasks. The same feature exists on x86 called 'rdpmc'. Unlike x86, userspace access will only be enabled for thread bound events. This could be extended if needed, but simplifies the implementation and reduces the chances for any information leaks (which the x86 implementation suffers from). PMU EL0 access will be enabled when an event with userspace access is part of the thread's context. This includes when the event is not scheduled on the PMU. There's some additional overhead clearing dirty counters when access is enabled in order to prevent leaking disabled counter data from other tasks. Unlike x86, enabling of userspace access must be requested with a new attr bit: config1:1. If the user requests userspace access with 64-bit counters, then the event open will fail if the h/w doesn't support 64-bit counters. Chaining is not supported with userspace access. The modes for config1 are as follows: config1 = 0 : user access disabled and always 32-bit config1 = 1 : user access disabled and always 64-bit (using chaining if needed) config1 = 2 : user access enabled and always 32-bit config1 = 3 : user access enabled and always 64-bit Based on work by Raphael Gault <raphael.gault@arm.com>, but has been completely re-written. Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-5-robh@kernel.org [will: Made armv8pmu_proc_user_access_handler() static] Signed-off-by: Will Deacon <will@kernel.org>
2021-12-08 20:11:23 +00:00
userpg->cap_user_rdpmc = armv8pmu_event_has_user_read(event);
if (userpg->cap_user_rdpmc) {
if (event->hw.flags & ARMPMU_EVT_64BIT)
userpg->pmc_width = 64;
else
userpg->pmc_width = 32;
}
do {
rd = sched_clock_read_begin(&seq);
if (rd->read_sched_clock != arch_timer_read_counter)
return;
userpg->time_mult = rd->mult;
userpg->time_shift = rd->shift;
userpg->time_zero = rd->epoch_ns;
userpg->time_cycles = rd->epoch_cyc;
userpg->time_mask = rd->sched_clock_mask;
/*
* Subtract the cycle base, such that software that
* doesn't know about cap_user_time_short still 'works'
* assuming no wraps.
*/
ns = mul_u64_u32_shr(rd->epoch_cyc, rd->mult, rd->shift);
userpg->time_zero -= ns;
} while (sched_clock_read_retry(seq));
userpg->time_offset = userpg->time_zero - now;
arm64: perf: Add cap_user_time aarch64 It is useful to get the running time of a thread. Doing so in an efficient manner can be important for performance of user applications. Avoiding system calls in `clock_gettime` when handling CLOCK_THREAD_CPUTIME_ID is important. Other clocks are handled in the VDSO, but CLOCK_THREAD_CPUTIME_ID falls back on the system call. CLOCK_THREAD_CPUTIME_ID is not handled in the VDSO since it would have costs associated with maintaining updated user space accessible time offsets. These offsets have to be updated everytime the a thread is scheduled/descheduled. However, for programs regularly checking the running time of a thread, this is a performance improvement. This patch takes a middle ground, and adds support for cap_user_time an optional feature of the perf_event API. This way costs are only incurred when the perf_event api is enabled. This is done the same way as it is in x86. Ultimately this allows calculating the thread running time in userspace on aarch64 as follows (adapted from perf_event_open manpage): u32 seq, time_mult, time_shift; u64 running, count, time_offset, quot, rem, delta; struct perf_event_mmap_page *pc; pc = buf; // buf is the perf event mmaped page as documented in the API. if (pc->cap_usr_time) { do { seq = pc->lock; barrier(); running = pc->time_running; count = readCNTVCT_EL0(); // Read ARM hardware clock. time_offset = pc->time_offset; time_mult = pc->time_mult; time_shift = pc->time_shift; barrier(); } while (pc->lock != seq); quot = (count >> time_shift); rem = count & (((u64)1 << time_shift) - 1); delta = time_offset + quot * time_mult + ((rem * time_mult) >> time_shift); running += delta; // running now has the current nanosecond level thread time. } Summary of changes in the patch: For aarch64 systems, make arch_perf_update_userpage update the timing information stored in the perf_event page. Requiring the following calculations: - Calculate the appropriate time_mult, and time_shift factors to convert ticks to nano seconds for the current clock frequency. - Adjust the mult and shift factors to avoid shift factors of 32 bits. (possibly unnecessary) - The time_offset userspace should apply when doing calculations: negative the current sched time (now), because time_running and time_enabled fields of the perf_event page have just been updated. Toggle bits to appropriate values: - Enable cap_user_time Signed-off-by: Michael O'Farrell <micpof@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-30 20:14:34 +00:00
/*
* time_shift is not expected to be greater than 31 due to
* the original published conversion algorithm shifting a
* 32-bit value (now specifies a 64-bit value) - refer
* perf_event_mmap_page documentation in perf_event.h.
*/
if (userpg->time_shift == 32) {
userpg->time_shift = 31;
arm64: perf: Add cap_user_time aarch64 It is useful to get the running time of a thread. Doing so in an efficient manner can be important for performance of user applications. Avoiding system calls in `clock_gettime` when handling CLOCK_THREAD_CPUTIME_ID is important. Other clocks are handled in the VDSO, but CLOCK_THREAD_CPUTIME_ID falls back on the system call. CLOCK_THREAD_CPUTIME_ID is not handled in the VDSO since it would have costs associated with maintaining updated user space accessible time offsets. These offsets have to be updated everytime the a thread is scheduled/descheduled. However, for programs regularly checking the running time of a thread, this is a performance improvement. This patch takes a middle ground, and adds support for cap_user_time an optional feature of the perf_event API. This way costs are only incurred when the perf_event api is enabled. This is done the same way as it is in x86. Ultimately this allows calculating the thread running time in userspace on aarch64 as follows (adapted from perf_event_open manpage): u32 seq, time_mult, time_shift; u64 running, count, time_offset, quot, rem, delta; struct perf_event_mmap_page *pc; pc = buf; // buf is the perf event mmaped page as documented in the API. if (pc->cap_usr_time) { do { seq = pc->lock; barrier(); running = pc->time_running; count = readCNTVCT_EL0(); // Read ARM hardware clock. time_offset = pc->time_offset; time_mult = pc->time_mult; time_shift = pc->time_shift; barrier(); } while (pc->lock != seq); quot = (count >> time_shift); rem = count & (((u64)1 << time_shift) - 1); delta = time_offset + quot * time_mult + ((rem * time_mult) >> time_shift); running += delta; // running now has the current nanosecond level thread time. } Summary of changes in the patch: For aarch64 systems, make arch_perf_update_userpage update the timing information stored in the perf_event page. Requiring the following calculations: - Calculate the appropriate time_mult, and time_shift factors to convert ticks to nano seconds for the current clock frequency. - Adjust the mult and shift factors to avoid shift factors of 32 bits. (possibly unnecessary) - The time_offset userspace should apply when doing calculations: negative the current sched time (now), because time_running and time_enabled fields of the perf_event page have just been updated. Toggle bits to appropriate values: - Enable cap_user_time Signed-off-by: Michael O'Farrell <micpof@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-30 20:14:34 +00:00
userpg->time_mult >>= 1;
}
/*
* Internal timekeeping for enabled/running/stopped times
* is always computed with the sched_clock.
*/
userpg->cap_user_time = 1;
userpg->cap_user_time_zero = 1;
userpg->cap_user_time_short = 1;
arm64: perf: Add cap_user_time aarch64 It is useful to get the running time of a thread. Doing so in an efficient manner can be important for performance of user applications. Avoiding system calls in `clock_gettime` when handling CLOCK_THREAD_CPUTIME_ID is important. Other clocks are handled in the VDSO, but CLOCK_THREAD_CPUTIME_ID falls back on the system call. CLOCK_THREAD_CPUTIME_ID is not handled in the VDSO since it would have costs associated with maintaining updated user space accessible time offsets. These offsets have to be updated everytime the a thread is scheduled/descheduled. However, for programs regularly checking the running time of a thread, this is a performance improvement. This patch takes a middle ground, and adds support for cap_user_time an optional feature of the perf_event API. This way costs are only incurred when the perf_event api is enabled. This is done the same way as it is in x86. Ultimately this allows calculating the thread running time in userspace on aarch64 as follows (adapted from perf_event_open manpage): u32 seq, time_mult, time_shift; u64 running, count, time_offset, quot, rem, delta; struct perf_event_mmap_page *pc; pc = buf; // buf is the perf event mmaped page as documented in the API. if (pc->cap_usr_time) { do { seq = pc->lock; barrier(); running = pc->time_running; count = readCNTVCT_EL0(); // Read ARM hardware clock. time_offset = pc->time_offset; time_mult = pc->time_mult; time_shift = pc->time_shift; barrier(); } while (pc->lock != seq); quot = (count >> time_shift); rem = count & (((u64)1 << time_shift) - 1); delta = time_offset + quot * time_mult + ((rem * time_mult) >> time_shift); running += delta; // running now has the current nanosecond level thread time. } Summary of changes in the patch: For aarch64 systems, make arch_perf_update_userpage update the timing information stored in the perf_event page. Requiring the following calculations: - Calculate the appropriate time_mult, and time_shift factors to convert ticks to nano seconds for the current clock frequency. - Adjust the mult and shift factors to avoid shift factors of 32 bits. (possibly unnecessary) - The time_offset userspace should apply when doing calculations: negative the current sched time (now), because time_running and time_enabled fields of the perf_event page have just been updated. Toggle bits to appropriate values: - Enable cap_user_time Signed-off-by: Michael O'Farrell <micpof@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-30 20:14:34 +00:00
}