android_kernel_motorola_sm6225/arch/x86/kernel/acpi/sleep.c
Rafael J. Wysocki 72ad5d77fb ACPI / Sleep: Allow the NVS saving to be skipped during suspend to RAM
Commit 2a6b69765a
(ACPI: Store NVS state even when entering suspend to RAM) caused the
ACPI suspend code save the NVS area during suspend and restore it
during resume unconditionally, although it is known that some systems
need to use acpi_sleep=s4_nonvs for hibernation to work.  To allow
the affected systems to avoid saving and restoring the NVS area
during suspend to RAM and resume, introduce kernel command line
option acpi_sleep=nonvs and make acpi_sleep=s4_nonvs work as its
alias temporarily (add acpi_sleep=s4_nonvs to the feature removal
file).

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16396 .

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-and-tested-by: tomas m <tmezzadra@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-07-24 23:26:09 -04:00

177 lines
4.7 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 <asm/segment.h>
#include <asm/desc.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;
#if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
static char temp_stack[4096];
#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;
/*
* Set up the wakeup GDT. We set these up as Big Real Mode,
* that is, with limits set to 4 GB. At least the Lenovo
* Thinkpad X61 is known to need this for the video BIOS
* initialization quirk to work; this is likely to also
* be the case for other laptops or integrated video devices.
*/
/* 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]: big real mode-like code segment */
header->wakeup_gdt[1] =
GDT_ENTRY(0x809b, acpi_wakeup_address, 0xfffff);
/* GDT[2]: big real mode-like data segment */
header->wakeup_gdt[2] =
GDT_ENTRY(0x8093, acpi_wakeup_address, 0xfffff);
#ifndef CONFIG_64BIT
store_gdt((struct desc_ptr *)&header->pmode_gdt);
if (rdmsr_safe(MSR_EFER, &header->pmode_efer_low,
&header->pmode_efer_high))
header->pmode_efer_low = header->pmode_efer_high = 0;
#endif /* !CONFIG_64BIT */
header->pmode_cr0 = read_cr0();
header->pmode_cr4 = read_cr4_safe();
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;
#ifdef CONFIG_SMP
stack_start.sp = temp_stack + sizeof(temp_stack);
early_gdt_descr.address =
(unsigned long)get_cpu_gdt_table(smp_processor_id());
initial_gs = per_cpu_offset(smp_processor_id());
#endif
initial_code = (unsigned long)wakeup_long64;
saved_magic = 0x123456789abcdef0L;
#endif /* CONFIG_64BIT */
return 0;
}
/*
* acpi_restore_state - undo effects of acpi_save_state_mem
*/
void acpi_restore_state_mem(void)
{
}
/**
* acpi_reserve_wakeup_memory - 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_wakeup_memory(void)
{
unsigned long mem;
if ((&wakeup_code_end - &wakeup_code_start) > WAKEUP_SIZE) {
printk(KERN_ERR
"ACPI: Wakeup code way too big, S3 disabled.\n");
return;
}
mem = find_e820_area(0, 1<<20, WAKEUP_SIZE, PAGE_SIZE);
if (mem == -1L) {
printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
return;
}
acpi_realmode = (unsigned long) phys_to_virt(mem);
acpi_wakeup_address = mem;
reserve_early(mem, mem + WAKEUP_SIZE, "ACPI WAKEUP");
}
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;
#ifdef CONFIG_HIBERNATION
if (strncmp(str, "s4_nohwsig", 10) == 0)
acpi_no_s4_hw_signature();
if (strncmp(str, "s4_nonvs", 8) == 0) {
pr_warning("ACPI: acpi_sleep=s4_nonvs is deprecated, "
"please use acpi_sleep=nonvs instead");
acpi_nvs_nosave();
}
#endif
if (strncmp(str, "nonvs", 5) == 0)
acpi_nvs_nosave();
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);