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linux-next/arch/x86/power/hibernate_asm_32.S
David Fries e532c06f2a x86: fix i486 suspend to disk CR4 oops
arch/x86/power/cpu_32.c __save_processor_state calls read_cr4()
only a i486 CPU doesn't have the CR4 register.  Trying to read it
produces an invalid opcode oops during suspend to disk.

Use the safe rc4 reading op instead. If the value to be written is
zero the write is skipped.

arch/x86/power/hibernate_asm_32.S
done: swapped the use of %eax and %ecx to use jecxz for
the zero test and jump over store to %cr4.
restore_image: s/%ecx/%eax/ to be consistent with done:

In addition to __save_processor_state, acpi_save_state_mem,
efi_call_phys_prelog, and efi_call_phys_epilog had checks added
(acpi restore was in assembly and already had a check for
non-zero).  There were other reads and writes of CR4, but MCE and
virtualization shouldn't be executed on a i486 anyway.

Signed-off-by: David Fries <david@fries.net>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-18 08:50:19 +02:00

82 lines
1.6 KiB
ArmAsm

.text
/*
* This may not use any stack, nor any variable that is not "NoSave":
*
* Its rewriting one kernel image with another. What is stack in "old"
* image could very well be data page in "new" image, and overwriting
* your own stack under you is bad idea.
*/
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/page.h>
#include <asm/asm-offsets.h>
.text
ENTRY(swsusp_arch_suspend)
movl %esp, saved_context_esp
movl %ebx, saved_context_ebx
movl %ebp, saved_context_ebp
movl %esi, saved_context_esi
movl %edi, saved_context_edi
pushfl ; popl saved_context_eflags
call swsusp_save
ret
ENTRY(restore_image)
movl resume_pg_dir, %eax
subl $__PAGE_OFFSET, %eax
movl %eax, %cr3
movl restore_pblist, %edx
.p2align 4,,7
copy_loop:
testl %edx, %edx
jz done
movl pbe_address(%edx), %esi
movl pbe_orig_address(%edx), %edi
movl $1024, %ecx
rep
movsl
movl pbe_next(%edx), %edx
jmp copy_loop
.p2align 4,,7
done:
/* go back to the original page tables */
movl $swapper_pg_dir, %eax
subl $__PAGE_OFFSET, %eax
movl %eax, %cr3
/* Flush TLB, including "global" things (vmalloc) */
movl mmu_cr4_features, %ecx
jecxz 1f # cr4 Pentium and higher, skip if zero
movl %ecx, %edx
andl $~(1<<7), %edx; # PGE
movl %edx, %cr4; # turn off PGE
1:
movl %cr3, %eax; # flush TLB
movl %eax, %cr3
jecxz 1f # cr4 Pentium and higher, skip if zero
movl %ecx, %cr4; # turn PGE back on
1:
movl saved_context_esp, %esp
movl saved_context_ebp, %ebp
movl saved_context_ebx, %ebx
movl saved_context_esi, %esi
movl saved_context_edi, %edi
pushl saved_context_eflags ; popfl
xorl %eax, %eax
ret