https://github.com/torvalds/linux
Tip revision: 52721d9d3334c1cb1f76219a161084094ec634dc authored by Linus Torvalds on 19 July 2015, 21:45:02 UTC
Linux 4.2-rc3
Linux 4.2-rc3
Tip revision: 52721d9
sleep.c
/*
* sleep.c - x86-specific ACPI sleep support.
*
* Copyright (C) 2001-2003 Patrick Mochel
* Copyright (C) 2001-2003 Pavel Machek <pavel@ucw.cz>
*/
#include <linux/acpi.h>
#include <linux/bootmem.h>
#include <linux/memblock.h>
#include <linux/dmi.h>
#include <linux/cpumask.h>
#include <asm/segment.h>
#include <asm/desc.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
#include <asm/realmode.h>
#include "../../realmode/rm/wakeup.h"
#include "sleep.h"
unsigned long acpi_realmode_flags;
#if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
static char temp_stack[4096];
#endif
/**
* x86_acpi_enter_sleep_state - enter sleep state
* @state: Sleep state to enter.
*
* Wrapper around acpi_enter_sleep_state() to be called by assmebly.
*/
acpi_status asmlinkage __visible x86_acpi_enter_sleep_state(u8 state)
{
return acpi_enter_sleep_state(state);
}
/**
* x86_acpi_suspend_lowlevel - save kernel state
*
* Create an identity mapped page table and copy the wakeup routine to
* low memory.
*/
int x86_acpi_suspend_lowlevel(void)
{
struct wakeup_header *header =
(struct wakeup_header *) __va(real_mode_header->wakeup_header);
if (header->signature != WAKEUP_HEADER_SIGNATURE) {
printk(KERN_ERR "wakeup header does not match\n");
return -EINVAL;
}
header->video_mode = saved_video_mode;
header->pmode_behavior = 0;
#ifndef CONFIG_64BIT
native_store_gdt((struct desc_ptr *)&header->pmode_gdt);
/*
* We have to check that we can write back the value, and not
* just read it. At least on 90 nm Pentium M (Family 6, Model
* 13), reading an invalid MSR is not guaranteed to trap, see
* Erratum X4 in "Intel Pentium M Processor on 90 nm Process
* with 2-MB L2 Cache and IntelĀ® Processor A100 and A110 on 90
* nm process with 512-KB L2 Cache Specification Update".
*/
if (!rdmsr_safe(MSR_EFER,
&header->pmode_efer_low,
&header->pmode_efer_high) &&
!wrmsr_safe(MSR_EFER,
header->pmode_efer_low,
header->pmode_efer_high))
header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
#endif /* !CONFIG_64BIT */
header->pmode_cr0 = read_cr0();
if (__this_cpu_read(cpu_info.cpuid_level) >= 0) {
header->pmode_cr4 = __read_cr4();
header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4);
}
if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
&header->pmode_misc_en_low,
&header->pmode_misc_en_high) &&
!wrmsr_safe(MSR_IA32_MISC_ENABLE,
header->pmode_misc_en_low,
header->pmode_misc_en_high))
header->pmode_behavior |=
(1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
header->realmode_flags = acpi_realmode_flags;
header->real_magic = 0x12345678;
#ifndef CONFIG_64BIT
header->pmode_entry = (u32)&wakeup_pmode_return;
header->pmode_cr3 = (u32)__pa_symbol(initial_page_table);
saved_magic = 0x12345678;
#else /* CONFIG_64BIT */
#ifdef CONFIG_SMP
stack_start = (unsigned long)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 */
do_suspend_lowlevel();
return 0;
}
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();
#endif
if (strncmp(str, "nonvs", 5) == 0)
acpi_nvs_nosave();
if (strncmp(str, "nonvs_s3", 8) == 0)
acpi_nvs_nosave_s3();
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);