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authorH. Peter Anvin <hpa@zytor.com>2008-06-24 23:03:48 +0200
committerIngo Molnar <mingo@elte.hu>2008-07-05 08:25:40 +0200
commit4b4f7280d7fd1feeff134c2cf2db32fd583b6c29 (patch)
treef10e83d5f2708cc0045a177cc4cdd68a0ff11762 /arch
parentb8a0b6ccf2ba2519ace65d782b41ee91bf3c3778 (diff)
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x86 ACPI: normalize segment descriptor register on resume
Some Dell laptops enter resume with apparent garbage in the segment descriptor registers (almost certainly the result of a botched transition from protected to real mode.) The only way to clean that up is to enter protected mode ourselves and clean out the descriptor registers. This fixes resume on Dell XPS M1210 and Dell D620. Reference: http://bugzilla.kernel.org/show_bug.cgi?id=10927 Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: pm list <linux-pm@lists.linux-foundation.org> Cc: Len Brown <lenb@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/acpi/realmode/wakeup.S38
-rw-r--r--arch/x86/kernel/acpi/realmode/wakeup.h5
-rw-r--r--arch/x86/kernel/acpi/sleep.c16
3 files changed, 57 insertions, 2 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
diff --git a/arch/x86/kernel/acpi/realmode/wakeup.h b/arch/x86/kernel/acpi/realmode/wakeup.h
index ef8166fe8020..69d38d0b2b64 100644
--- a/arch/x86/kernel/acpi/realmode/wakeup.h
+++ b/arch/x86/kernel/acpi/realmode/wakeup.h
@@ -24,6 +24,11 @@ struct wakeup_header {
u32 realmode_flags;
u32 real_magic;
u16 trampoline_segment; /* segment with trampoline code, 64-bit only */
+ u8 _pad1;
+ u8 wakeup_jmp;
+ u16 wakeup_jmp_off;
+ u16 wakeup_jmp_seg;
+ u64 wakeup_gdt[3];
u32 signature; /* To check we have correct structure */
} __attribute__((__packed__));
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index afc25ee9964b..36af01f029ed 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -50,6 +50,20 @@ int acpi_save_state_mem(void)
header->video_mode = saved_video_mode;
+ header->wakeup_jmp_seg = acpi_wakeup_address >> 4;
+ /* GDT[0]: GDT self-pointer */
+ header->wakeup_gdt[0] =
+ (u64)(sizeof(header->wakeup_gdt) - 1) +
+ ((u64)(acpi_wakeup_address +
+ ((char *)&header->wakeup_gdt - (char *)acpi_realmode))
+ << 16);
+ /* GDT[1]: real-mode-like code segment */
+ header->wakeup_gdt[1] = (0x009bULL << 40) +
+ ((u64)acpi_wakeup_address << 16) + 0xffff;
+ /* GDT[2]: real-mode-like data segment */
+ header->wakeup_gdt[2] = (0x0093ULL << 40) +
+ ((u64)acpi_wakeup_address << 16) + 0xffff;
+
#ifndef CONFIG_64BIT
store_gdt((struct desc_ptr *)&header->pmode_gdt);
@@ -111,7 +125,7 @@ void __init acpi_reserve_bootmem(void)
return;
}
- acpi_wakeup_address = acpi_realmode;
+ acpi_wakeup_address = virt_to_phys((void *)acpi_realmode);
}