linux-next/include/linux/arm_sdei.h
D Scott Phillips 5cd474e573 arm64: sdei: abort running SDEI handlers during crash
Interrupts are blocked in SDEI context, per the SDEI spec: "The client
interrupts cannot preempt the event handler." If we crashed in the SDEI
handler-running context (as with ACPI's AGDI) then we need to clean up the
SDEI state before proceeding to the crash kernel so that the crash kernel
can have working interrupts.

Track the active SDEI handler per-cpu so that we can COMPLETE_AND_RESUME
the handler, discarding the interrupted context.

Fixes: f5df269618 ("arm64: kernel: Add arch-specific SDEI entry code and CPU masking")
Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com>
Cc: stable@vger.kernel.org
Reviewed-by: James Morse <james.morse@arm.com>
Tested-by: Mihai Carabas <mihai.carabas@oracle.com>
Link: https://lore.kernel.org/r/20230627002939.2758-1-scott@os.amperecomputing.com
Signed-off-by: Will Deacon <will@kernel.org>
2023-08-04 17:35:33 +01:00

87 lines
2.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2017 Arm Ltd.
#ifndef __LINUX_ARM_SDEI_H
#define __LINUX_ARM_SDEI_H
#include <uapi/linux/arm_sdei.h>
#include <acpi/ghes.h>
#ifdef CONFIG_ARM_SDE_INTERFACE
#include <asm/sdei.h>
#endif
/* Arch code should override this to set the entry point from firmware... */
#ifndef sdei_arch_get_entry_point
#define sdei_arch_get_entry_point(conduit) (0)
#endif
/*
* When an event occurs sdei_event_handler() will call a user-provided callback
* like this in NMI context on the CPU that received the event.
*/
typedef int (sdei_event_callback)(u32 event, struct pt_regs *regs, void *arg);
/*
* Register your callback to claim an event. The event must be described
* by firmware.
*/
int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg);
/*
* Calls to sdei_event_unregister() may return EINPROGRESS. Keep calling
* it until it succeeds.
*/
int sdei_event_unregister(u32 event_num);
int sdei_event_enable(u32 event_num);
int sdei_event_disable(u32 event_num);
/* GHES register/unregister helpers */
int sdei_register_ghes(struct ghes *ghes, sdei_event_callback *normal_cb,
sdei_event_callback *critical_cb);
int sdei_unregister_ghes(struct ghes *ghes);
#ifdef CONFIG_ARM_SDE_INTERFACE
/* For use by arch code when CPU hotplug notifiers are not appropriate. */
int sdei_mask_local_cpu(void);
int sdei_unmask_local_cpu(void);
void __init sdei_init(void);
void sdei_handler_abort(void);
#else
static inline int sdei_mask_local_cpu(void) { return 0; }
static inline int sdei_unmask_local_cpu(void) { return 0; }
static inline void sdei_init(void) { }
static inline void sdei_handler_abort(void) { }
#endif /* CONFIG_ARM_SDE_INTERFACE */
/*
* This struct represents an event that has been registered. The driver
* maintains a list of all events, and which ones are registered. (Private
* events have one entry in the list, but are registered on each CPU).
* A pointer to this struct is passed to firmware, and back to the event
* handler. The event handler can then use this to invoke the registered
* callback, without having to walk the list.
*
* For CPU private events, this structure is per-cpu.
*/
struct sdei_registered_event {
/* For use by arch code: */
struct pt_regs interrupted_regs;
sdei_event_callback *callback;
void *callback_arg;
u32 event_num;
u8 priority;
};
/* The arch code entry point should then call this when an event arrives. */
int notrace sdei_event_handler(struct pt_regs *regs,
struct sdei_registered_event *arg);
/* arch code may use this to retrieve the extra registers. */
int sdei_api_event_context(u32 query, u64 *result);
#endif /* __LINUX_ARM_SDEI_H */