diff --git a/arch/arm64/include/asm/suspend.h b/arch/arm64/include/asm/suspend.h
index e9c149c042e09703c864ef7c6101602134676678..456d67c1f0fac270cb0438d62fd35a48bc70e1c8 100644
--- a/arch/arm64/include/asm/suspend.h
+++ b/arch/arm64/include/asm/suspend.h
@@ -21,6 +21,7 @@ struct sleep_save_sp {
phys_addr_t save_ptr_stash_phys;
};
+extern int __cpu_suspend(unsigned long arg, int (*fn)(unsigned long));
extern void cpu_resume(void);
extern int cpu_suspend(unsigned long);
diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
index b1925729c692c72a0d7a1e7a33a7b2ca0eba591e..a564b440416a8cde66ed8a31ade2a30d4a04e391 100644
--- a/arch/arm64/kernel/sleep.S
+++ b/arch/arm64/kernel/sleep.S
@@ -49,28 +49,39 @@
orr \dst, \dst, \mask // dst|=(aff3>>rs3)
.endm
/*
- * Save CPU state for a suspend. This saves callee registers, and allocates
- * space on the kernel stack to save the CPU specific registers + some
- * other data for resume.
+ * Save CPU state for a suspend and execute the suspend finisher.
+ * On success it will return 0 through cpu_resume - ie through a CPU
+ * soft/hard reboot from the reset vector.
+ * On failure it returns the suspend finisher return value or force
+ * -EOPNOTSUPP if the finisher erroneously returns 0 (the suspend finisher
+ * is not allowed to return, if it does this must be considered failure).
+ * It saves callee registers, and allocates space on the kernel stack
+ * to save the CPU specific registers + some other data for resume.
*
* x0 = suspend finisher argument
+ * x1 = suspend finisher function pointer
*/
-ENTRY(__cpu_suspend)
+ENTRY(__cpu_suspend_enter)
stp x29, lr, [sp, #-96]!
stp x19, x20, [sp,#16]
stp x21, x22, [sp,#32]
stp x23, x24, [sp,#48]
stp x25, x26, [sp,#64]
stp x27, x28, [sp,#80]
+ /*
+ * Stash suspend finisher and its argument in x20 and x19
+ */
+ mov x19, x0
+ mov x20, x1
mov x2, sp
sub sp, sp, #CPU_SUSPEND_SZ // allocate cpu_suspend_ctx
- mov x1, sp
+ mov x0, sp
/*
- * x1 now points to struct cpu_suspend_ctx allocated on the stack
+ * x0 now points to struct cpu_suspend_ctx allocated on the stack
*/
- str x2, [x1, #CPU_CTX_SP]
- ldr x2, =sleep_save_sp
- ldr x2, [x2, #SLEEP_SAVE_SP_VIRT]
+ str x2, [x0, #CPU_CTX_SP]
+ ldr x1, =sleep_save_sp
+ ldr x1, [x1, #SLEEP_SAVE_SP_VIRT]
#ifdef CONFIG_SMP
mrs x7, mpidr_el1
ldr x9, =mpidr_hash
@@ -82,11 +93,21 @@ ENTRY(__cpu_suspend)
ldp w3, w4, [x9, #MPIDR_HASH_SHIFTS]
ldp w5, w6, [x9, #(MPIDR_HASH_SHIFTS + 8)]
compute_mpidr_hash x8, x3, x4, x5, x6, x7, x10
- add x2, x2, x8, lsl #3
+ add x1, x1, x8, lsl #3
#endif
- bl __cpu_suspend_finisher
+ bl __cpu_suspend_save
+ /*
+ * Grab suspend finisher in x20 and its argument in x19
+ */
+ mov x0, x19
+ mov x1, x20
+ /*
+ * We are ready for power down, fire off the suspend finisher
+ * in x1, with argument in x0
+ */
+ blr x1
/*
- * Never gets here, unless suspend fails.
+ * Never gets here, unless suspend finisher fails.
* Successful cpu_suspend should return from cpu_resume, returning
* through this code path is considered an error
* If the return value is set to 0 force x0 = -EOPNOTSUPP
@@ -103,7 +124,7 @@ ENTRY(__cpu_suspend)
ldp x27, x28, [sp, #80]
ldp x29, lr, [sp], #96
ret
-ENDPROC(__cpu_suspend)
+ENDPROC(__cpu_suspend_enter)
.ltorg
/*
diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c
index 55a99b9a97e0f49409a59e6f72ee2441cc35225f..13ad4dbb1615fc9ad5419393f75907fb41560cc9 100644
--- a/arch/arm64/kernel/suspend.c
+++ b/arch/arm64/kernel/suspend.c
@@ -9,22 +9,19 @@
#include <asm/suspend.h>
#include <asm/tlbflush.h>
-extern int __cpu_suspend(unsigned long);
+extern int __cpu_suspend_enter(unsigned long arg, int (*fn)(unsigned long));
/*
- * This is called by __cpu_suspend() to save the state, and do whatever
+ * This is called by __cpu_suspend_enter() to save the state, and do whatever
* flushing is required to ensure that when the CPU goes to sleep we have
* the necessary data available when the caches are not searched.
*
- * @arg: Argument to pass to suspend operations
- * @ptr: CPU context virtual address
- * @save_ptr: address of the location where the context physical address
- * must be saved
+ * ptr: CPU context virtual address
+ * save_ptr: address of the location where the context physical address
+ * must be saved
*/
-int __cpu_suspend_finisher(unsigned long arg, struct cpu_suspend_ctx *ptr,
- phys_addr_t *save_ptr)
+void notrace __cpu_suspend_save(struct cpu_suspend_ctx *ptr,
+ phys_addr_t *save_ptr)
{
- int cpu = smp_processor_id();
-
*save_ptr = virt_to_phys(ptr);
cpu_do_suspend(ptr);
@@ -35,8 +32,6 @@ int __cpu_suspend_finisher(unsigned long arg, struct cpu_suspend_ctx *ptr,
*/
__flush_dcache_area(ptr, sizeof(*ptr));
__flush_dcache_area(save_ptr, sizeof(*save_ptr));
-
- return cpu_ops[cpu]->cpu_suspend(arg);
}
/*
@@ -56,15 +51,15 @@ void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *))
}
/**
- * cpu_suspend
+ * cpu_suspend() - function to enter a low-power state
+ * @arg: argument to pass to CPU suspend operations
*
- * @arg: argument to pass to the finisher function
+ * Return: 0 on success, -EOPNOTSUPP if CPU suspend hook not initialized, CPU
+ * operations back-end error code otherwise.
*/
int cpu_suspend(unsigned long arg)
{
- struct mm_struct *mm = current->active_mm;
- int ret, cpu = smp_processor_id();
- unsigned long flags;
+ int cpu = smp_processor_id();
/*
* If cpu_ops have not been registered or suspend
@@ -72,6 +67,21 @@ int cpu_suspend(unsigned long arg)
*/
if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_suspend)
return -EOPNOTSUPP;
+ return cpu_ops[cpu]->cpu_suspend(arg);
+}
+
+/*
+ * __cpu_suspend
+ *
+ * arg: argument to pass to the finisher function
+ * fn: finisher function pointer
+ *
+ */
+int __cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
+{
+ struct mm_struct *mm = current->active_mm;
+ int ret;
+ unsigned long flags;
/*
* From this point debug exceptions are disabled to prevent
@@ -86,7 +96,7 @@ int cpu_suspend(unsigned long arg)
* page tables, so that the thread address space is properly
* set-up on function return.
*/
- ret = __cpu_suspend(arg);
+ ret = __cpu_suspend_enter(arg, fn);
if (ret == 0) {
cpu_switch_mm(mm->pgd, mm);
flush_tlb_all();
@@ -95,7 +105,7 @@ int cpu_suspend(unsigned long arg)
* Restore per-cpu offset before any kernel
* subsystem relying on it has a chance to run.
*/
- set_my_cpu_offset(per_cpu_offset(cpu));
+ set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
/*
* Restore HW breakpoint registers to sane values