From adc9b2dfd00924e9e9b98613f36a6cb8c51f0dc6 Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 27 Apr 2016 17:47:06 +0100 Subject: arm64: kernel: Rework finisher callback out of __cpu_suspend_enter() Hibernate could make use of the cpu_suspend() code to save/restore cpu state, however it needs to be able to return '0' from the 'finisher'. Rework cpu_suspend() so that the finisher is called from C code, independently from the save/restore of cpu state. Space to save the context in is allocated in the caller's stack frame, and passed into __cpu_suspend_enter(). Hibernate's use of this API will look like a copy of the cpu_suspend() function. Signed-off-by: James Morse Acked-by: Lorenzo Pieralisi Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon --- arch/arm64/include/asm/suspend.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'arch/arm64/include') diff --git a/arch/arm64/include/asm/suspend.h b/arch/arm64/include/asm/suspend.h index 59a5b0f1..365d8cd 100644 --- a/arch/arm64/include/asm/suspend.h +++ b/arch/arm64/include/asm/suspend.h @@ -2,6 +2,7 @@ #define __ASM_SUSPEND_H #define NR_CTX_REGS 11 +#define NR_CALLEE_SAVED_REGS 12 /* * struct cpu_suspend_ctx must be 16-byte aligned since it is allocated on @@ -21,6 +22,25 @@ struct sleep_save_sp { phys_addr_t save_ptr_stash_phys; }; +/* + * 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 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); #endif -- cgit v1.1