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authorJames Morse <james.morse@arm.com>2016-04-27 17:47:06 +0100
committerWill Deacon <will.deacon@arm.com>2016-04-28 12:05:46 +0100
commitadc9b2dfd00924e9e9b98613f36a6cb8c51f0dc6 (patch)
tree127168cb8901a501fa01f87491e18566f81f5630 /arch/arm64/include/asm
parent67f6919766620e7ea7aab11a6a3470dc7b451359 (diff)
downloadop-kernel-dev-adc9b2dfd00924e9e9b98613f36a6cb8c51f0dc6.zip
op-kernel-dev-adc9b2dfd00924e9e9b98613f36a6cb8c51f0dc6.tar.gz
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 <james.morse@arm.com> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/include/asm')
-rw-r--r--arch/arm64/include/asm/suspend.h20
1 files changed, 20 insertions, 0 deletions
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
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