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authorLinus Torvalds <torvalds@linux-foundation.org>2008-07-05 13:08:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-05 13:08:38 -0700
commit537388bb6563bfde7c0307b95ecc1f7a1ae39b02 (patch)
tree7ca5fd476ef71cab2064d716046be4cc281f918b /arch/x86/kernel/acpi/realmode/wakeup.S
parent20cbc972617069c1ed434f62151e4de57d26ea46 (diff)
parenta1716d508abf77e4bd02c275ab9293b9866929f3 (diff)
downloadlwn-537388bb6563bfde7c0307b95ecc1f7a1ae39b02.tar.gz
lwn-537388bb6563bfde7c0307b95ecc1f7a1ae39b02.zip
Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86 ACPI: fix resume from suspend to RAM on uniprocessor x86-64 x86 ACPI: normalize segment descriptor register on resume
Diffstat (limited to 'arch/x86/kernel/acpi/realmode/wakeup.S')
-rw-r--r--arch/x86/kernel/acpi/realmode/wakeup.S38
1 files changed, 37 insertions, 1 deletions
diff --git a/arch/x86/kernel/acpi/realmode/wakeup.S b/arch/x86/kernel/acpi/realmode/wakeup.S
index f9b77fb37e5b..3355973b12ac 100644
--- a/arch/x86/kernel/acpi/realmode/wakeup.S
+++ b/arch/x86/kernel/acpi/realmode/wakeup.S
@@ -5,6 +5,7 @@
#include <asm/msr-index.h>
#include <asm/page.h>
#include <asm/pgtable.h>
+#include <asm/processor-flags.h>
.code16
.section ".header", "a"
@@ -24,6 +25,11 @@ pmode_gdt: .quad 0
realmode_flags: .long 0
real_magic: .long 0
trampoline_segment: .word 0
+_pad1: .byte 0
+wakeup_jmp: .byte 0xea /* ljmpw */
+wakeup_jmp_off: .word 3f
+wakeup_jmp_seg: .word 0
+wakeup_gdt: .quad 0, 0, 0
signature: .long 0x51ee1111
.text
@@ -34,11 +40,34 @@ _start:
cli
cld
+ /* Apparently some dimwit BIOS programmers don't know how to
+ program a PM to RM transition, and we might end up here with
+ junk in the data segment descriptor registers. The only way
+ to repair that is to go into PM and fix it ourselves... */
+ movw $16, %cx
+ lgdtl %cs:wakeup_gdt
+ movl %cr0, %eax
+ orb $X86_CR0_PE, %al
+ movl %eax, %cr0
+ jmp 1f
+1: ljmpw $8, $2f
+2:
+ movw %cx, %ds
+ movw %cx, %es
+ movw %cx, %ss
+ movw %cx, %fs
+ movw %cx, %gs
+
+ andb $~X86_CR0_PE, %al
+ movl %eax, %cr0
+ jmp wakeup_jmp
+3:
/* Set up segments */
movw %cs, %ax
movw %ax, %ds
movw %ax, %es
movw %ax, %ss
+ lidtl wakeup_idt
movl $wakeup_stack_end, %esp
@@ -98,7 +127,14 @@ bogus_real_magic:
jmp 1b
.data
- .balign 4
+ .balign 8
+
+ /* This is the standard real-mode IDT */
+wakeup_idt:
+ .word 0xffff /* limit */
+ .long 0 /* address */
+ .word 0
+
.globl HEAP, heap_end
HEAP:
.long wakeup_heap