root/arch/x86/kernel/acpi/sleep.c

DEFINITIONS

1. acpi_save_state_mem
2. acpi_restore_state_mem
3. acpi_reserve_bootmem
4. acpi_sleep_setup

/*
 * 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 "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[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;

        /*
         * 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);

        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_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 + 4096;
#endif
        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;
#ifdef CONFIG_HIBERNATION
                if (strncmp(str, "s4_nohwsig", 10) == 0)
                        acpi_no_s4_hw_signature();
#endif
                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);