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Diffstat (limited to 'arch/arm64/kernel/sleep.S')
-rw-r--r--arch/arm64/kernel/sleep.S47
1 files changed, 34 insertions, 13 deletions
diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
index b1925729c692..a564b440416a 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
/*