linux/arch/arm64/include/asm/suspend.h
Mark Rutland 623b476fc8 arm64: move sp_el0 and tpidr_el1 into cpu_suspend_ctx
When returning from idle, we rely on the fact that thread_info lives at
the end of the kernel stack, and restore this by masking the saved stack
pointer. Subsequent patches will sever the relationship between the
stack and thread_info, and to cater for this we must save/restore sp_el0
explicitly, storing it in cpu_suspend_ctx.

As cpu_suspend_ctx must be doubleword aligned, this leaves us with an
extra slot in cpu_suspend_ctx. We can use this to save/restore tpidr_el1
in the same way, which simplifies the code, avoiding pointer chasing on
the restore path (as we no longer need to load thread_info::cpu followed
by the relevant slot in __per_cpu_offset based on this).

This patch stashes both registers in cpu_suspend_ctx.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: James Morse <james.morse@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-11-11 18:25:44 +00:00

54 lines
1.6 KiB
C

#ifndef __ASM_SUSPEND_H
#define __ASM_SUSPEND_H
#define NR_CTX_REGS 12
#define NR_CALLEE_SAVED_REGS 12
/*
* struct cpu_suspend_ctx must be 16-byte aligned since it is allocated on
* the stack, which must be 16-byte aligned on v8
*/
struct cpu_suspend_ctx {
/*
* This struct must be kept in sync with
* cpu_do_{suspend/resume} in mm/proc.S
*/
u64 ctx_regs[NR_CTX_REGS];
u64 sp;
} __aligned(16);
/*
* Memory to save the cpu state is allocated on the stack by
* __cpu_suspend_enter()'s caller, and populated by __cpu_suspend_enter().
* This data must survive until cpu_resume() is called.
*
* This struct desribes the size and the layout of the saved cpu state.
* The layout of the callee_saved_regs is defined by the implementation
* of __cpu_suspend_enter(), and cpu_resume(). This struct must be passed
* in by the caller as __cpu_suspend_enter()'s stack-frame is gone once it
* returns, and the data would be subsequently corrupted by the call to the
* finisher.
*/
struct sleep_stack_data {
struct cpu_suspend_ctx system_regs;
unsigned long callee_saved_regs[NR_CALLEE_SAVED_REGS];
};
extern unsigned long *sleep_save_stash;
extern int cpu_suspend(unsigned long arg, int (*fn)(unsigned long));
extern void cpu_resume(void);
int __cpu_suspend_enter(struct sleep_stack_data *state);
void __cpu_suspend_exit(void);
void _cpu_resume(void);
int swsusp_arch_suspend(void);
int swsusp_arch_resume(void);
int arch_hibernation_header_save(void *addr, unsigned int max_size);
int arch_hibernation_header_restore(void *addr);
/* Used to resume on the CPU we hibernated on */
int hibernate_resume_nonboot_cpu_disable(void);
#endif