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arm64: Change cpu_resume() to enable mmu early then access sleep_sp by va

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By enabling the MMU early in cpu_resume(), the sleep_save_sp and stack can
be accessed by VA, which avoids the need to convert-addresses and clean to
PoC on the suspend path.

MMU setup is shared with the boot path, meaning the swapper_pg_dir is
restored directly: ttbr1_el1 is no longer saved/restored.

struct sleep_save_sp is removed, replacing it with a single array of
pointers.

cpu_do_{suspend,resume} could be further reduced to not restore: cpacr_el1,
mdscr_el1, tcr_el1, vbar_el1 and sctlr_el1, all of which are set by
__cpu_setup(). However these values all contain res0 bits that may be used
to enable future features.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
James Morse
2016-04-27 17:47:07 +01:00
committed by Will Deacon
parent adc9b2dfd0
commit cabe1c81ea
7 changed files with 57 additions and 115 deletions
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9
arch/arm64/include/asm/suspend.h
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@@ -1,7 +1,7 @@
#ifndef __ASM_SUSPEND_H
#define __ASM_SUSPEND_H
#define NR_CTX_REGS 11
#define NR_CTX_REGS 10
#define NR_CALLEE_SAVED_REGS 12
/*
@@ -17,11 +17,6 @@ struct cpu_suspend_ctx {
u64 sp;
} __aligned(16);
struct sleep_save_sp {
phys_addr_t *save_ptr_stash;
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().
@@ -39,6 +34,8 @@ struct sleep_stack_data {
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);