linux/arch/x86/kernel/acpi/sleep.c
Rafael J. Wysocki d8f3de0d24 Suspend-related patches for 2.6.27
ACPI PM: Add possibility to change suspend sequence

There are some systems out there that don't work correctly with
our current suspend/hibernation code ordering.  Provide a workaround
for these systems allowing them to pass 'acpi_sleep=old_ordering' in
the kernel command line so that it will use the pre-ACPI 2.0 ("old")
suspend code ordering.

Unfortunately, this requires us to add a platform hook to the
resuming of devices for recovering the platform in case one of the
device drivers' .suspend() routines returns error code.  Namely,
ACPI 1.0 specifies that _PTS should be called before suspending
devices, but _WAK still should be called before resuming them in
order to undo the changes made by _PTS.  However, if there is an
error during suspending devices, they are automatically resumed
without returning control to the PM core, so the _WAK has to be
called from within device_resume() in that cases.

The patch also reorders and refactors the ACPI suspend/hibernation
code to avoid duplication as far as reasonably possible.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-06-12 14:25:09 -07:00

136 lines
3.3 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;
#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 = 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;
if (strncmp(str, "old_ordering", 12) == 0)
acpi_old_suspend_ordering();
str = strchr(str, ',');
if (str != NULL)
str += strspn(str, ", \t");
}
return 1;
}
__setup("acpi_sleep=", acpi_sleep_setup);