android_kernel_motorola_sm6225/arch/x86/kernel/acpi/sleep.c
H. Peter Anvin 4b4f7280d7 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>
2008-07-05 08:25:40 +02:00

148 lines
3.7 KiB
C

/*
* sleep.c - x86-specific ACPI sleep support.
*
* Copyright (C) 2001-2003 Patrick Mochel
* Copyright (C) 2001-2003 Pavel Machek <pavel@suse.cz>
*/
#include <linux/acpi.h>
#include <linux/bootmem.h>
#include <linux/dmi.h>
#include <linux/cpumask.h>
#include "realmode/wakeup.h"
#include "sleep.h"
unsigned long acpi_wakeup_address;
unsigned long acpi_realmode_flags;
/* address in low memory of the wakeup routine. */
static unsigned long acpi_realmode;
#ifdef CONFIG_64BIT
static char temp_stack[10240];
#endif
/**
* acpi_save_state_mem - save kernel state
*
* Create an identity mapped page table and copy the wakeup routine to
* low memory.
*
* Note that this is too late to change acpi_wakeup_address.
*/
int acpi_save_state_mem(void)
{
struct wakeup_header *header;
if (!acpi_realmode) {
printk(KERN_ERR "Could not allocate memory during boot, "
"S3 disabled\n");
return -ENOMEM;
}
memcpy((void *)acpi_realmode, &wakeup_code_start, WAKEUP_SIZE);
header = (struct wakeup_header *)(acpi_realmode + HEADER_OFFSET);
if (header->signature != 0x51ee1111) {
printk(KERN_ERR "wakeup header does not match\n");
return -EINVAL;
}
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);
header->pmode_efer_low = nx_enabled;
if (header->pmode_efer_low & 1) {
/* This is strange, why not save efer, always? */
rdmsr(MSR_EFER, header->pmode_efer_low,
header->pmode_efer_high);
}
#endif /* !CONFIG_64BIT */
header->pmode_cr0 = read_cr0();
header->pmode_cr4 = read_cr4();
header->realmode_flags = acpi_realmode_flags;
header->real_magic = 0x12345678;
#ifndef CONFIG_64BIT
header->pmode_entry = (u32)&wakeup_pmode_return;
header->pmode_cr3 = (u32)(swsusp_pg_dir - __PAGE_OFFSET);
saved_magic = 0x12345678;
#else /* CONFIG_64BIT */
header->trampoline_segment = setup_trampoline() >> 4;
init_rsp = (unsigned long)temp_stack + 4096;
initial_code = (unsigned long)wakeup_long64;
saved_magic = 0x123456789abcdef0;
#endif /* CONFIG_64BIT */
return 0;
}
/*
* acpi_restore_state - undo effects of acpi_save_state_mem
*/
void acpi_restore_state_mem(void)
{
}
/**
* acpi_reserve_bootmem - do _very_ early ACPI initialisation
*
* We allocate a page from the first 1MB of memory for the wakeup
* routine for when we come back from a sleep state. The
* runtime allocator allows specification of <16MB pages, but not
* <1MB pages.
*/
void __init acpi_reserve_bootmem(void)
{
if ((&wakeup_code_end - &wakeup_code_start) > WAKEUP_SIZE) {
printk(KERN_ERR
"ACPI: Wakeup code way too big, S3 disabled.\n");
return;
}
acpi_realmode = (unsigned long)alloc_bootmem_low(WAKEUP_SIZE);
if (!acpi_realmode) {
printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
return;
}
acpi_wakeup_address = virt_to_phys((void *)acpi_realmode);
}
static int __init acpi_sleep_setup(char *str)
{
while ((str != NULL) && (*str != '\0')) {
if (strncmp(str, "s3_bios", 7) == 0)
acpi_realmode_flags |= 1;
if (strncmp(str, "s3_mode", 7) == 0)
acpi_realmode_flags |= 2;
if (strncmp(str, "s3_beep", 7) == 0)
acpi_realmode_flags |= 4;
str = strchr(str, ',');
if (str != NULL)
str += strspn(str, ", \t");
}
return 1;
}
__setup("acpi_sleep=", acpi_sleep_setup);