RISC-V Fixes for 6.8-rc7

* A fix for detecting ".option arch" support on not-yet-released LLVM
   builds.
 * A fix for a missing TLB flush when modifying non-leaf PTEs.
 * A handufl of fixes for T-Head custom extensions.
 * A fix for systems with the legacy PMU, that manifests as a crash on
   kernels built without SBI PMU support.
 * A fix for systems that clear *envcfg on suspend, which manifests as
   cbo.zero trapping after resume.
 * A pair of fixes for Svnapot systems, including removing Svnapot
   support for huge vmalloc/vmap regions.
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Merge tag 'riscv-for-linus-6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Palmer Dabbelt:

 - detect ".option arch" support on not-yet-released LLVM builds

 - fix missing TLB flush when modifying non-leaf PTEs

 - fixes for T-Head custom extensions

 - fix for systems with the legacy PMU, that manifests as a crash on
   kernels built without SBI PMU support

 - fix for systems that clear *envcfg on suspend, which manifests as
   cbo.zero trapping after resume

 - fixes for Svnapot systems, including removing Svnapot support for
   huge vmalloc/vmap regions

* tag 'riscv-for-linus-6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Sparse-Memory/vmemmap out-of-bounds fix
  riscv: Fix pte_leaf_size() for NAPOT
  Revert "riscv: mm: support Svnapot in huge vmap"
  riscv: Save/restore envcfg CSR during CPU suspend
  riscv: Add a custom ISA extension for the [ms]envcfg CSR
  riscv: Fix enabling cbo.zero when running in M-mode
  perf: RISCV: Fix panic on pmu overflow handler
  MAINTAINERS: Update SiFive driver maintainers
  drivers: perf: ctr_get_width function for legacy is not defined
  drivers: perf: added capabilities for legacy PMU
  RISC-V: Ignore V from the riscv,isa DT property on older T-Head CPUs
  riscv: Fix build error if !CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
  riscv: mm: fix NOCACHE_THEAD does not set bit[61] correctly
  riscv: add CALLER_ADDRx support
  RISC-V: Drop invalid test from CONFIG_AS_HAS_OPTION_ARCH
  kbuild: Add -Wa,--fatal-warnings to as-instr invocation
  riscv: tlb: fix __p*d_free_tlb()

MAINTAINERS

@@ -1395,6 +1395,7 @@ F:	drivers/hwmon/max31760.c
 
 ANALOGBITS PLL LIBRARIES
 M:	Paul Walmsley <paul.walmsley@sifive.com>
+M:	Samuel Holland <samuel.holland@sifive.com>
 S:	Supported
 F:	drivers/clk/analogbits/*
 F:	include/linux/clk/analogbits*
@@ -16743,6 +16744,7 @@ F:	drivers/pci/controller/dwc/*layerscape*
 PCI DRIVER FOR FU740
 M:	Paul Walmsley <paul.walmsley@sifive.com>
 M:	Greentime Hu <greentime.hu@sifive.com>
+M:	Samuel Holland <samuel.holland@sifive.com>
 L:	linux-pci@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/pci/sifive,fu740-pcie.yaml
@@ -19988,35 +19990,14 @@ S:	Maintained
 F:	drivers/watchdog/simatic-ipc-wdt.c
 
 SIFIVE DRIVERS
-M:	Palmer Dabbelt <palmer@dabbelt.com>
 M:	Paul Walmsley <paul.walmsley@sifive.com>
+M:	Samuel Holland <samuel.holland@sifive.com>
 L:	linux-riscv@lists.infradead.org
 S:	Supported
-N:	sifive
-K:	[^@]sifive
-
-SIFIVE CACHE DRIVER
-M:	Conor Dooley <conor@kernel.org>
-L:	linux-riscv@lists.infradead.org
-S:	Maintained
-F:	Documentation/devicetree/bindings/cache/sifive,ccache0.yaml
-F:	drivers/cache/sifive_ccache.c
-
-SIFIVE FU540 SYSTEM-ON-CHIP
-M:	Paul Walmsley <paul.walmsley@sifive.com>
-M:	Palmer Dabbelt <palmer@dabbelt.com>
-L:	linux-riscv@lists.infradead.org
-S:	Supported
-T:	git git://git.kernel.org/pub/scm/linux/kernel/git/pjw/sifive.git
-N:	fu540
-K:	fu540
-
-SIFIVE PDMA DRIVER
-M:	Green Wan <green.wan@sifive.com>
-S:	Maintained
-F:	Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
 F:	drivers/dma/sf-pdma/
-
+N:	sifive
+K:	fu[57]40
+K:	[^@]sifive
 
 SILEAD TOUCHSCREEN DRIVER
 M:	Hans de Goede <hdegoede@redhat.com>

arch/riscv/Kconfig

@@ -315,7 +315,6 @@ config AS_HAS_OPTION_ARCH
 	# https://reviews.llvm.org/D123515
 	def_bool y
 	depends on $(as-instr, .option arch$(comma) +m)
-	depends on !$(as-instr, .option arch$(comma) -i)
 
 source "arch/riscv/Kconfig.socs"
 source "arch/riscv/Kconfig.errata"

arch/riscv/include/asm/csr.h

@@ -424,6 +424,7 @@
 # define CSR_STATUS	CSR_MSTATUS
 # define CSR_IE		CSR_MIE
 # define CSR_TVEC	CSR_MTVEC
+# define CSR_ENVCFG	CSR_MENVCFG
 # define CSR_SCRATCH	CSR_MSCRATCH
 # define CSR_EPC	CSR_MEPC
 # define CSR_CAUSE	CSR_MCAUSE
@@ -448,6 +449,7 @@
 # define CSR_STATUS	CSR_SSTATUS
 # define CSR_IE		CSR_SIE
 # define CSR_TVEC	CSR_STVEC
+# define CSR_ENVCFG	CSR_SENVCFG
 # define CSR_SCRATCH	CSR_SSCRATCH
 # define CSR_EPC	CSR_SEPC
 # define CSR_CAUSE	CSR_SCAUSE

arch/riscv/include/asm/ftrace.h

@@ -25,6 +25,11 @@
 
 #define ARCH_SUPPORTS_FTRACE_OPS 1
 #ifndef __ASSEMBLY__
+
+extern void *return_address(unsigned int level);
+
+#define ftrace_return_address(n) return_address(n)
+
 void MCOUNT_NAME(void);
 static inline unsigned long ftrace_call_adjust(unsigned long addr)
 {

arch/riscv/include/asm/hugetlb.h

@@ -11,8 +11,10 @@ static inline void arch_clear_hugepage_flags(struct page *page)
 }
 #define arch_clear_hugepage_flags arch_clear_hugepage_flags
 
+#ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
 bool arch_hugetlb_migration_supported(struct hstate *h);
 #define arch_hugetlb_migration_supported arch_hugetlb_migration_supported
+#endif
 
 #ifdef CONFIG_RISCV_ISA_SVNAPOT
 #define __HAVE_ARCH_HUGE_PTE_CLEAR

arch/riscv/include/asm/hwcap.h

@@ -81,6 +81,8 @@
 #define RISCV_ISA_EXT_ZTSO		72
 #define RISCV_ISA_EXT_ZACAS		73
 
+#define RISCV_ISA_EXT_XLINUXENVCFG	127
+
 #define RISCV_ISA_EXT_MAX		128
 #define RISCV_ISA_EXT_INVALID		U32_MAX
 

arch/riscv/include/asm/pgalloc.h

@@ -95,7 +95,13 @@ static inline void pud_free(struct mm_struct *mm, pud_t *pud)
 		__pud_free(mm, pud);
 }
 
-#define __pud_free_tlb(tlb, pud, addr)  pud_free((tlb)->mm, pud)
+#define __pud_free_tlb(tlb, pud, addr)					\
+do {									\
+	if (pgtable_l4_enabled) {					\
+		pagetable_pud_dtor(virt_to_ptdesc(pud));		\
+		tlb_remove_page_ptdesc((tlb), virt_to_ptdesc(pud));	\
+	}								\
+} while (0)
 
 #define p4d_alloc_one p4d_alloc_one
 static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
@@ -124,7 +130,11 @@ static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
 		__p4d_free(mm, p4d);
 }
 
-#define __p4d_free_tlb(tlb, p4d, addr)  p4d_free((tlb)->mm, p4d)
+#define __p4d_free_tlb(tlb, p4d, addr)					\
+do {									\
+	if (pgtable_l5_enabled)						\
+		tlb_remove_page_ptdesc((tlb), virt_to_ptdesc(p4d));	\
+} while (0)
 #endif /* __PAGETABLE_PMD_FOLDED */
 
 static inline void sync_kernel_mappings(pgd_t *pgd)
@@ -149,7 +159,11 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 
 #ifndef __PAGETABLE_PMD_FOLDED
 
-#define __pmd_free_tlb(tlb, pmd, addr)  pmd_free((tlb)->mm, pmd)
+#define __pmd_free_tlb(tlb, pmd, addr)				\
+do {								\
+	pagetable_pmd_dtor(virt_to_ptdesc(pmd));		\
+	tlb_remove_page_ptdesc((tlb), virt_to_ptdesc(pmd));	\
+} while (0)
 
 #endif /* __PAGETABLE_PMD_FOLDED */
 

arch/riscv/include/asm/pgtable-64.h

@@ -136,7 +136,7 @@ enum napot_cont_order {
  * 10010 - IO   Strongly-ordered, Non-cacheable, Non-bufferable, Shareable, Non-trustable
  */
 #define _PAGE_PMA_THEAD		((1UL << 62) | (1UL << 61) | (1UL << 60))
-#define _PAGE_NOCACHE_THEAD	((1UL < 61) | (1UL << 60))
+#define _PAGE_NOCACHE_THEAD	((1UL << 61) | (1UL << 60))
 #define _PAGE_IO_THEAD		((1UL << 63) | (1UL << 60))
 #define _PAGE_MTMASK_THEAD	(_PAGE_PMA_THEAD | _PAGE_IO_THEAD | (1UL << 59))
 

arch/riscv/include/asm/pgtable.h

@@ -84,7 +84,7 @@
  * Define vmemmap for pfn_to_page & page_to_pfn calls. Needed if kernel
  * is configured with CONFIG_SPARSEMEM_VMEMMAP enabled.
  */
-#define vmemmap		((struct page *)VMEMMAP_START)
+#define vmemmap		((struct page *)VMEMMAP_START - (phys_ram_base >> PAGE_SHIFT))
 
 #define PCI_IO_SIZE      SZ_16M
 #define PCI_IO_END       VMEMMAP_START
@@ -439,6 +439,10 @@ static inline pte_t pte_mkhuge(pte_t pte)
 	return pte;
 }
 
+#define pte_leaf_size(pte)	(pte_napot(pte) ?				\
+					napot_cont_size(napot_cont_order(pte)) :\
+					PAGE_SIZE)
+
 #ifdef CONFIG_NUMA_BALANCING
 /*
  * See the comment in include/asm-generic/pgtable.h

arch/riscv/include/asm/suspend.h

@@ -14,6 +14,7 @@ struct suspend_context {
 	struct pt_regs regs;
 	/* Saved and restored by high-level functions */
 	unsigned long scratch;
+	unsigned long envcfg;
 	unsigned long tvec;
 	unsigned long ie;
 #ifdef CONFIG_MMU

arch/riscv/include/asm/vmalloc.h

@@ -19,65 +19,6 @@ static inline bool arch_vmap_pmd_supported(pgprot_t prot)
 	return true;
 }
 
-#ifdef CONFIG_RISCV_ISA_SVNAPOT
+#endif
-#include <linux/pgtable.h>
 
-#define arch_vmap_pte_range_map_size arch_vmap_pte_range_map_size
-static inline unsigned long arch_vmap_pte_range_map_size(unsigned long addr, unsigned long end,
-							 u64 pfn, unsigned int max_page_shift)
-{
-	unsigned long map_size = PAGE_SIZE;
-	unsigned long size, order;
-
-	if (!has_svnapot())
-		return map_size;
-
-	for_each_napot_order_rev(order) {
-		if (napot_cont_shift(order) > max_page_shift)
-			continue;
-
-		size = napot_cont_size(order);
-		if (end - addr < size)
-			continue;
-
-		if (!IS_ALIGNED(addr, size))
-			continue;
-
-		if (!IS_ALIGNED(PFN_PHYS(pfn), size))
-			continue;
-
-		map_size = size;
-		break;
-	}
-
-	return map_size;
-}
-
-#define arch_vmap_pte_supported_shift arch_vmap_pte_supported_shift
-static inline int arch_vmap_pte_supported_shift(unsigned long size)
-{
-	int shift = PAGE_SHIFT;
-	unsigned long order;
-
-	if (!has_svnapot())
-		return shift;
-
-	WARN_ON_ONCE(size >= PMD_SIZE);
-
-	for_each_napot_order_rev(order) {
-		if (napot_cont_size(order) > size)
-			continue;
-
-		if (!IS_ALIGNED(size, napot_cont_size(order)))
-			continue;
-
-		shift = napot_cont_shift(order);
-		break;
-	}
-
-	return shift;
-}
-
-#endif /* CONFIG_RISCV_ISA_SVNAPOT */
-#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
 #endif /* _ASM_RISCV_VMALLOC_H */

arch/riscv/kernel/Makefile

@@ -7,6 +7,7 @@ ifdef CONFIG_FTRACE
 CFLAGS_REMOVE_ftrace.o	= $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_patch.o	= $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_sbi.o	= $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_return_address.o	= $(CC_FLAGS_FTRACE)
 endif
 CFLAGS_syscall_table.o	+= $(call cc-option,-Wno-override-init,)
 CFLAGS_compat_syscall_table.o += $(call cc-option,-Wno-override-init,)
@@ -46,6 +47,7 @@ obj-y	+= irq.o
 obj-y	+= process.o
 obj-y	+= ptrace.o
 obj-y	+= reset.o
+obj-y	+= return_address.o
 obj-y	+= setup.o
 obj-y	+= signal.o
 obj-y	+= syscall_table.o

arch/riscv/kernel/cpufeature.c

@@ -24,6 +24,7 @@
 #include <asm/hwprobe.h>
 #include <asm/patch.h>
 #include <asm/processor.h>
+#include <asm/sbi.h>
 #include <asm/vector.h>
 
 #include "copy-unaligned.h"
@@ -201,6 +202,16 @@ static const unsigned int riscv_zvbb_exts[] = {
 	RISCV_ISA_EXT_ZVKB
 };
 
+/*
+ * While the [ms]envcfg CSRs were not defined until version 1.12 of the RISC-V
+ * privileged ISA, the existence of the CSRs is implied by any extension which
+ * specifies [ms]envcfg bit(s). Hence, we define a custom ISA extension for the
+ * existence of the CSR, and treat it as a subset of those other extensions.
+ */
+static const unsigned int riscv_xlinuxenvcfg_exts[] = {
+	RISCV_ISA_EXT_XLINUXENVCFG
+};
+
 /*
  * The canonical order of ISA extension names in the ISA string is defined in
  * chapter 27 of the unprivileged specification.
@@ -250,8 +261,8 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_DATA(c, RISCV_ISA_EXT_c),
 	__RISCV_ISA_EXT_DATA(v, RISCV_ISA_EXT_v),
 	__RISCV_ISA_EXT_DATA(h, RISCV_ISA_EXT_h),
-	__RISCV_ISA_EXT_DATA(zicbom, RISCV_ISA_EXT_ZICBOM),
+	__RISCV_ISA_EXT_SUPERSET(zicbom, RISCV_ISA_EXT_ZICBOM, riscv_xlinuxenvcfg_exts),
-	__RISCV_ISA_EXT_DATA(zicboz, RISCV_ISA_EXT_ZICBOZ),
+	__RISCV_ISA_EXT_SUPERSET(zicboz, RISCV_ISA_EXT_ZICBOZ, riscv_xlinuxenvcfg_exts),
 	__RISCV_ISA_EXT_DATA(zicntr, RISCV_ISA_EXT_ZICNTR),
 	__RISCV_ISA_EXT_DATA(zicond, RISCV_ISA_EXT_ZICOND),
 	__RISCV_ISA_EXT_DATA(zicsr, RISCV_ISA_EXT_ZICSR),
@@ -538,6 +549,20 @@ static void __init riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap)
 			set_bit(RISCV_ISA_EXT_ZIHPM, isainfo->isa);
 		}
 
+		/*
+		 * "V" in ISA strings is ambiguous in practice: it should mean
+		 * just the standard V-1.0 but vendors aren't well behaved.
+		 * Many vendors with T-Head CPU cores which implement the 0.7.1
+		 * version of the vector specification put "v" into their DTs.
+		 * CPU cores with the ratified spec will contain non-zero
+		 * marchid.
+		 */
+		if (acpi_disabled && riscv_cached_mvendorid(cpu) == THEAD_VENDOR_ID &&
+		    riscv_cached_marchid(cpu) == 0x0) {
+			this_hwcap &= ~isa2hwcap[RISCV_ISA_EXT_v];
+			clear_bit(RISCV_ISA_EXT_v, isainfo->isa);
+		}
+
 		/*
 		 * All "okay" hart should have same isa. Set HWCAP based on
 		 * common capabilities of every "okay" hart, in case they don't
@@ -950,7 +975,7 @@ arch_initcall(check_unaligned_access_all_cpus);
 void riscv_user_isa_enable(void)
 {
 	if (riscv_cpu_has_extension_unlikely(smp_processor_id(), RISCV_ISA_EXT_ZICBOZ))
-		csr_set(CSR_SENVCFG, ENVCFG_CBZE);
+		csr_set(CSR_ENVCFG, ENVCFG_CBZE);
 }
 
 #ifdef CONFIG_RISCV_ALTERNATIVE

arch/riscv/kernel/return_address.c

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This code come from arch/arm64/kernel/return_address.c
+ *
+ * Copyright (C) 2023 SiFive.
+ */
+
+#include <linux/export.h>
+#include <linux/kprobes.h>
+#include <linux/stacktrace.h>
+
+struct return_address_data {
+	unsigned int level;
+	void *addr;
+};
+
+static bool save_return_addr(void *d, unsigned long pc)
+{
+	struct return_address_data *data = d;
+
+	if (!data->level) {
+		data->addr = (void *)pc;
+		return false;
+	}
+
+	--data->level;
+
+	return true;
+}
+NOKPROBE_SYMBOL(save_return_addr);
+
+noinline void *return_address(unsigned int level)
+{
+	struct return_address_data data;
+
+	data.level = level + 3;
+	data.addr = NULL;
+
+	arch_stack_walk(save_return_addr, &data, current, NULL);
+
+	if (!data.level)
+		return data.addr;
+	else
+		return NULL;
+
+}
+EXPORT_SYMBOL_GPL(return_address);
+NOKPROBE_SYMBOL(return_address);

arch/riscv/kernel/suspend.c

@@ -15,6 +15,8 @@
 void suspend_save_csrs(struct suspend_context *context)
 {
 	context->scratch = csr_read(CSR_SCRATCH);
+	if (riscv_cpu_has_extension_unlikely(smp_processor_id(), RISCV_ISA_EXT_XLINUXENVCFG))
+		context->envcfg = csr_read(CSR_ENVCFG);
 	context->tvec = csr_read(CSR_TVEC);
 	context->ie = csr_read(CSR_IE);
 
@@ -36,6 +38,8 @@ void suspend_save_csrs(struct suspend_context *context)
 void suspend_restore_csrs(struct suspend_context *context)
 {
 	csr_write(CSR_SCRATCH, context->scratch);
+	if (riscv_cpu_has_extension_unlikely(smp_processor_id(), RISCV_ISA_EXT_XLINUXENVCFG))
+		csr_write(CSR_ENVCFG, context->envcfg);
 	csr_write(CSR_TVEC, context->tvec);
 	csr_write(CSR_IE, context->ie);
 

arch/riscv/mm/hugetlbpage.c

@@ -426,10 +426,12 @@ bool __init arch_hugetlb_valid_size(unsigned long size)
 	return __hugetlb_valid_size(size);
 }
 
+#ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
 bool arch_hugetlb_migration_supported(struct hstate *h)
 {
 	return __hugetlb_valid_size(huge_page_size(h));
 }
+#endif
 
 #ifdef CONFIG_CONTIG_ALLOC
 static __init int gigantic_pages_init(void)

drivers/perf/riscv_pmu.c

@@ -150,19 +150,11 @@ u64 riscv_pmu_ctr_get_width_mask(struct perf_event *event)
 	struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu);
 	struct hw_perf_event *hwc = &event->hw;
 
-	if (!rvpmu->ctr_get_width)
+	if (hwc->idx == -1)
-	/**
+		/* Handle init case where idx is not initialized yet */
-	 * If the pmu driver doesn't support counter width, set it to default
+		cwidth = rvpmu->ctr_get_width(0);
-	 * maximum allowed by the specification.
+	else
-	 */
+		cwidth = rvpmu->ctr_get_width(hwc->idx);
-		cwidth = 63;
-	else {
-		if (hwc->idx == -1)
-			/* Handle init case where idx is not initialized yet */
-			cwidth = rvpmu->ctr_get_width(0);
-		else
-			cwidth = rvpmu->ctr_get_width(hwc->idx);
-	}
 
 	return GENMASK_ULL(cwidth, 0);
 }

drivers/perf/riscv_pmu_legacy.c

@@ -37,6 +37,12 @@ static int pmu_legacy_event_map(struct perf_event *event, u64 *config)
 	return pmu_legacy_ctr_get_idx(event);
 }
 
+/* cycle & instret are always 64 bit, one bit less according to SBI spec */
+static int pmu_legacy_ctr_get_width(int idx)
+{
+	return 63;
+}
+
 static u64 pmu_legacy_read_ctr(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
@@ -111,12 +117,14 @@ static void pmu_legacy_init(struct riscv_pmu *pmu)
 	pmu->ctr_stop = NULL;
 	pmu->event_map = pmu_legacy_event_map;
 	pmu->ctr_get_idx = pmu_legacy_ctr_get_idx;
-	pmu->ctr_get_width = NULL;
+	pmu->ctr_get_width = pmu_legacy_ctr_get_width;
 	pmu->ctr_clear_idx = NULL;
 	pmu->ctr_read = pmu_legacy_read_ctr;
 	pmu->event_mapped = pmu_legacy_event_mapped;
 	pmu->event_unmapped = pmu_legacy_event_unmapped;
 	pmu->csr_index = pmu_legacy_csr_index;
+	pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
+	pmu->pmu.capabilities |= PERF_PMU_CAP_NO_EXCLUDE;
 
 	perf_pmu_register(&pmu->pmu, "cpu", PERF_TYPE_RAW);
 }

drivers/perf/riscv_pmu_sbi.c

@@ -512,7 +512,7 @@ static void pmu_sbi_set_scounteren(void *arg)
 
 	if (event->hw.idx != -1)
 		csr_write(CSR_SCOUNTEREN,
-			  csr_read(CSR_SCOUNTEREN) | (1 << pmu_sbi_csr_index(event)));
+			  csr_read(CSR_SCOUNTEREN) | BIT(pmu_sbi_csr_index(event)));
 }
 
 static void pmu_sbi_reset_scounteren(void *arg)
@@ -521,7 +521,7 @@ static void pmu_sbi_reset_scounteren(void *arg)
 
 	if (event->hw.idx != -1)
 		csr_write(CSR_SCOUNTEREN,
-			  csr_read(CSR_SCOUNTEREN) & ~(1 << pmu_sbi_csr_index(event)));
+			  csr_read(CSR_SCOUNTEREN) & ~BIT(pmu_sbi_csr_index(event)));
 }
 
 static void pmu_sbi_ctr_start(struct perf_event *event, u64 ival)
@@ -731,14 +731,14 @@ static irqreturn_t pmu_sbi_ovf_handler(int irq, void *dev)
 		/* compute hardware counter index */
 		hidx = info->csr - CSR_CYCLE;
 		/* check if the corresponding bit is set in sscountovf */
-		if (!(overflow & (1 << hidx)))
+		if (!(overflow & BIT(hidx)))
 			continue;
 
 		/*
 		 * Keep a track of overflowed counters so that they can be started
 		 * with updated initial value.
 		 */
-		overflowed_ctrs |= 1 << lidx;
+		overflowed_ctrs |= BIT(lidx);
 		hw_evt = &event->hw;
 		riscv_pmu_event_update(event);
 		perf_sample_data_init(&data, 0, hw_evt->last_period);

scripts/Kconfig.include

@@ -33,7 +33,7 @@ ld-option = $(success,$(LD) -v $(1))
 
 # $(as-instr,<instr>)
 # Return y if the assembler supports <instr>, n otherwise
-as-instr = $(success,printf "%b\n" "$(1)" | $(CC) $(CLANG_FLAGS) -c -x assembler-with-cpp -o /dev/null -)
+as-instr = $(success,printf "%b\n" "$(1)" | $(CC) $(CLANG_FLAGS) -Wa$(comma)--fatal-warnings -c -x assembler-with-cpp -o /dev/null -)
 
 # check if $(CC) and $(LD) exist
 $(error-if,$(failure,command -v $(CC)),C compiler '$(CC)' not found)

scripts/Makefile.compiler

@@ -38,7 +38,7 @@ as-option = $(call try-run,\
 # Usage: aflags-y += $(call as-instr,instr,option1,option2)
 
 as-instr = $(call try-run,\
-	printf "%b\n" "$(1)" | $(CC) -Werror $(CLANG_FLAGS) $(KBUILD_AFLAGS) -c -x assembler-with-cpp -o "$$TMP" -,$(2),$(3))
+	printf "%b\n" "$(1)" | $(CC) -Werror $(CLANG_FLAGS) $(KBUILD_AFLAGS) -Wa$(comma)--fatal-warnings -c -x assembler-with-cpp -o "$$TMP" -,$(2),$(3))
 
 # __cc-option
 # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)