From cd74257b974d6d26442c97891c4d05772748b177 Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Date: Sun, 22 Apr 2012 23:03:18 -0400
Subject: x86, acpi: Call acpi_enter_sleep_state via an asmlinkage C function
from assembler
With commit a2ef5c4fd44ce3922435139393b89f2cce47f576
"ACPI: Move module parameter gts and bfs to sleep.c" the
wake_sleep_flags is required when calling acpi_enter_sleep_state.
The assembler code in wakeup_*.S did not do that. One solution
is to call it from assembler and stick the wake_sleep_flags on
the stack (for 32-bit) or in %esi (for 64-bit). hpa and rafael
both suggested however to create a wrapper function to call
acpi_enter_sleep_state and call said wrapper function
("acpi_enter_s3") from assembler.
For 32-bit, the acpi_enter_s3 ends up looking as so:
push %ebp
mov %esp,%ebp
sub $0x8,%esp
movzbl 0xc1809314,%eax [wake_sleep_flags]
movl $0x3,(%esp)
mov %eax,0x4(%esp)
call 0xc12d1fa0 <acpi_enter_sleep_state>
leave
ret
And 64-bit:
movzbl 0x9afde1(%rip),%esi [wake_sleep_flags]
push %rbp
mov $0x3,%edi
mov %rsp,%rbp
callq 0xffffffff812e9800 <acpi_enter_sleep_state>
leaveq
retq
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
[v2: Remove extra assembler operations, per hpa review]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1335150198-21899-3-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/kernel/acpi/sleep.c | 4 ++++
1 file changed, 4 insertions(+)
(limited to 'arch/x86/kernel/acpi/sleep.c')
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index 103b6ab368d3..146a49c763a4 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -24,6 +24,10 @@ unsigned long acpi_realmode_flags;
static char temp_stack[4096];
#endif
+asmlinkage void acpi_enter_s3(void)
+{
+ acpi_enter_sleep_state(3, wake_sleep_flags);
+}
/**
* acpi_suspend_lowlevel - save kernel state
*
--
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