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| author | David Fries <david@fries.net> | 2008-08-17 23:03:40 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-08-18 08:50:19 +0200 |
| commit | e532c06f2a835b5cc4f4166f467437d9b09c1d0e (patch) | |
| tree | 762fa0f0c22dc1af7d9d6e918f4d48ced8910a4e /arch/x86/power | |
| parent | 39e00fe20aaad4326ed5e0e3221451732bc7f679 (diff) | |
| download | linux-e532c06f2a835b5cc4f4166f467437d9b09c1d0e.tar.gz | |
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>
Diffstat (limited to 'arch/x86/power')
| -rw-r--r-- | arch/x86/power/cpu_32.c | 6 | ||||
| -rw-r--r-- | arch/x86/power/hibernate_asm_32.S | 26 |
2 files changed, 19 insertions, 13 deletions
diff --git a/arch/x86/power/cpu_32.c b/arch/x86/power/cpu_32.c index 7dc5d5cf50a2..d3e083dea720 100644 --- a/arch/x86/power/cpu_32.c +++ b/arch/x86/power/cpu_32.c @@ -45,7 +45,7 @@ static void __save_processor_state(struct saved_context *ctxt) ctxt->cr0 = read_cr0(); ctxt->cr2 = read_cr2(); ctxt->cr3 = read_cr3(); - ctxt->cr4 = read_cr4(); + ctxt->cr4 = read_cr4_safe(); } /* Needed by apm.c */ @@ -98,7 +98,9 @@ static void __restore_processor_state(struct saved_context *ctxt) /* * control registers */ - write_cr4(ctxt->cr4); + /* cr4 was introduced in the Pentium CPU */ + if (ctxt->cr4) + write_cr4(ctxt->cr4); write_cr3(ctxt->cr3); write_cr2(ctxt->cr2); write_cr0(ctxt->cr0); diff --git a/arch/x86/power/hibernate_asm_32.S b/arch/x86/power/hibernate_asm_32.S index b95aa6cfe3cb..4fc7e872c85e 100644 --- a/arch/x86/power/hibernate_asm_32.S +++ b/arch/x86/power/hibernate_asm_32.S @@ -28,9 +28,9 @@ ENTRY(swsusp_arch_suspend) ret ENTRY(restore_image) - movl resume_pg_dir, %ecx - subl $__PAGE_OFFSET, %ecx - movl %ecx, %cr3 + movl resume_pg_dir, %eax + subl $__PAGE_OFFSET, %eax + movl %eax, %cr3 movl restore_pblist, %edx .p2align 4,,7 @@ -52,17 +52,21 @@ copy_loop: done: /* go back to the original page tables */ - movl $swapper_pg_dir, %ecx - subl $__PAGE_OFFSET, %ecx - movl %ecx, %cr3 + movl $swapper_pg_dir, %eax + subl $__PAGE_OFFSET, %eax + movl %eax, %cr3 /* Flush TLB, including "global" things (vmalloc) */ - movl mmu_cr4_features, %eax - movl %eax, %edx + 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 - movl %cr3, %ecx; # flush TLB - movl %ecx, %cr3 - movl %eax, %cr4; # turn PGE back on +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 |