arch/x86/kernel/acpi/sleep.c

   1 /*
   2  * sleep.c - x86-specific ACPI sleep support.
   3  *
   4  *  Copyright (C) 2001-2003 Patrick Mochel
   5  *  Copyright (C) 2001-2003 Pavel Machek <pavel@ucw.cz>
   6  */
   7
   8 #include <linux/acpi.h>
   9 #include <linux/bootmem.h>
  10 #include <linux/memblock.h>
  11 #include <linux/dmi.h>
  12 #include <linux/cpumask.h>
  13 #include <asm/segment.h>
  14 #include <asm/desc.h>
  15 #include <asm/pgtable.h>
  16 #include <asm/cacheflush.h>
  17 #include <asm/realmode.h>
  18
  19 #include "../../realmode/rm/wakeup.h"
  20 #include "sleep.h"
  21
  22 unsigned long acpi_realmode_flags;
  23
  24 #if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
  25 static char temp_stack[4096];
  26 #endif
  27
  28 /**
  29  * x86_acpi_suspend_lowlevel - save kernel state
  30  *
  31  * Create an identity mapped page table and copy the wakeup routine to
  32  * low memory.
  33  */
  34 int x86_acpi_suspend_lowlevel(void)
  35 {
  36         struct wakeup_header *header =
  37                 (struct wakeup_header *) __va(real_mode_header->wakeup_header);
  38
  39         if (header->signature != WAKEUP_HEADER_SIGNATURE) {
  40                 printk(KERN_ERR "wakeup header does not match\n");
  41                 return -EINVAL;
  42         }
  43
  44         header->video_mode = saved_video_mode;
  45
  46         header->pmode_behavior = 0;
  47
  48 #ifndef CONFIG_64BIT
  49         native_store_gdt((struct desc_ptr *)&header->pmode_gdt);
  50
  51         /*
  52          * We have to check that we can write back the value, and not
  53          * just read it.  At least on 90 nm Pentium M (Family 6, Model
  54          * 13), reading an invalid MSR is not guaranteed to trap, see
  55          * Erratum X4 in "Intel Pentium M Processor on 90 nm Process
  56          * with 2-MB L2 Cache and Intel® Processor A100 and A110 on 90
  57          * nm process with 512-KB L2 Cache Specification Update".
  58          */
  59         if (!rdmsr_safe(MSR_EFER,
  60                         &header->pmode_efer_low,
  61                         &header->pmode_efer_high) &&
  62             !wrmsr_safe(MSR_EFER,
  63                         header->pmode_efer_low,
  64                         header->pmode_efer_high))
  65                 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
  66 #endif /* !CONFIG_64BIT */
  67
  68         header->pmode_cr0 = read_cr0();
  69         if (__this_cpu_read(cpu_info.cpuid_level) >= 0) {
  70                 header->pmode_cr4 = read_cr4();
  71                 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4);
  72         }
  73         if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
  74                         &header->pmode_misc_en_low,
  75                         &header->pmode_misc_en_high) &&
  76             !wrmsr_safe(MSR_IA32_MISC_ENABLE,
  77                         header->pmode_misc_en_low,
  78                         header->pmode_misc_en_high))
  79                 header->pmode_behavior |=
  80                         (1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
  81         header->realmode_flags = acpi_realmode_flags;
  82         header->real_magic = 0x12345678;
  83
  84 #ifndef CONFIG_64BIT
  85         header->pmode_entry = (u32)&wakeup_pmode_return;
  86         header->pmode_cr3 = (u32)__pa_symbol(initial_page_table);
  87         saved_magic = 0x12345678;
  88 #else /* CONFIG_64BIT */
  89 #ifdef CONFIG_SMP
  90         stack_start = (unsigned long)temp_stack + sizeof(temp_stack);
  91         early_gdt_descr.address =
  92                         (unsigned long)get_cpu_gdt_table(smp_processor_id());
  93         initial_gs = per_cpu_offset(smp_processor_id());
  94 #endif
  95         initial_code = (unsigned long)wakeup_long64;
  96        saved_magic = 0x123456789abcdef0L;
  97 #endif /* CONFIG_64BIT */
  98
  99         do_suspend_lowlevel();
 100         return 0;
 101 }
 102
 103 static int __init acpi_sleep_setup(char *str)
 104 {
 105         while ((str != NULL) && (*str != '\0')) {
 106                 if (strncmp(str, "s3_bios", 7) == 0)
 107                         acpi_realmode_flags |= 1;
 108                 if (strncmp(str, "s3_mode", 7) == 0)
 109                         acpi_realmode_flags |= 2;
 110                 if (strncmp(str, "s3_beep", 7) == 0)
 111                         acpi_realmode_flags |= 4;
 112 #ifdef CONFIG_HIBERNATION
 113                 if (strncmp(str, "s4_nohwsig", 10) == 0)
 114                         acpi_no_s4_hw_signature();
 115 #endif
 116                 if (strncmp(str, "nonvs", 5) == 0)
 117                         acpi_nvs_nosave();
 118                 if (strncmp(str, "nonvs_s3", 8) == 0)
 119                         acpi_nvs_nosave_s3();
 120                 if (strncmp(str, "old_ordering", 12) == 0)
 121                         acpi_old_suspend_ordering();
 122                 str = strchr(str, ',');
 123                 if (str != NULL)
 124                         str += strspn(str, ", \t");
 125         }
 126         return 1;
 127 }
 128
 129 __setup("acpi_sleep=", acpi_sleep_setup);