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 <linux/ftrace.h>
  20 #include "../../realmode/rm/wakeup.h"
  21 #include "sleep.h"
  22
  23 unsigned long acpi_realmode_flags;
  24
  25 #if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
  26 static char temp_stack[4096];
  27 #endif
  28
  29 /**
  30  * x86_acpi_suspend_lowlevel - save kernel state
  31  *
  32  * Create an identity mapped page table and copy the wakeup routine to
  33  * low memory.
  34  */
  35 int x86_acpi_suspend_lowlevel(void)
  36 {
  37         struct wakeup_header *header =
  38                 (struct wakeup_header *) __va(real_mode_header->wakeup_header);
  39
  40         if (header->signature != WAKEUP_HEADER_SIGNATURE) {
  41                 printk(KERN_ERR "wakeup header does not match\n");
  42                 return -EINVAL;
  43         }
  44
  45         header->video_mode = saved_video_mode;
  46
  47         header->pmode_behavior = 0;
  48
  49 #ifndef CONFIG_64BIT
  50         native_store_gdt((struct desc_ptr *)&header->pmode_gdt);
  51
  52         /*
  53          * We have to check that we can write back the value, and not
  54          * just read it.  At least on 90 nm Pentium M (Family 6, Model
  55          * 13), reading an invalid MSR is not guaranteed to trap, see
  56          * Erratum X4 in "Intel Pentium M Processor on 90 nm Process
  57          * with 2-MB L2 Cache and Intel® Processor A100 and A110 on 90
  58          * nm process with 512-KB L2 Cache Specification Update".
  59          */
  60         if (!rdmsr_safe(MSR_EFER,
  61                         &header->pmode_efer_low,
  62                         &header->pmode_efer_high) &&
  63             !wrmsr_safe(MSR_EFER,
  64                         header->pmode_efer_low,
  65                         header->pmode_efer_high))
  66                 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
  67 #endif /* !CONFIG_64BIT */
  68
  69         header->pmode_cr0 = read_cr0();
  70         if (__this_cpu_read(cpu_info.cpuid_level) >= 0) {
  71                 header->pmode_cr4 = read_cr4();
  72                 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4);
  73         }
  74         if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
  75                         &header->pmode_misc_en_low,
  76                         &header->pmode_misc_en_high) &&
  77             !wrmsr_safe(MSR_IA32_MISC_ENABLE,
  78                         header->pmode_misc_en_low,
  79                         header->pmode_misc_en_high))
  80                 header->pmode_behavior |=
  81                         (1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
  82         header->realmode_flags = acpi_realmode_flags;
  83         header->real_magic = 0x12345678;
  84
  85 #ifndef CONFIG_64BIT
  86         header->pmode_entry = (u32)&wakeup_pmode_return;
  87         header->pmode_cr3 = (u32)__pa_symbol(initial_page_table);
  88         saved_magic = 0x12345678;
  89 #else /* CONFIG_64BIT */
  90 #ifdef CONFIG_SMP
  91         stack_start = (unsigned long)temp_stack + sizeof(temp_stack);
  92         early_gdt_descr.address =
  93                         (unsigned long)get_cpu_gdt_table(smp_processor_id());
  94         initial_gs = per_cpu_offset(smp_processor_id());
  95 #endif
  96         initial_code = (unsigned long)wakeup_long64;
  97        saved_magic = 0x123456789abcdef0L;
  98 #endif /* CONFIG_64BIT */
  99
 100         /*
 101          * Pause/unpause graph tracing around do_suspend_lowlevel as it has
 102          * inconsistent call/return info after it jumps to the wakeup vector.
 103          */
 104         pause_graph_tracing();
 105         do_suspend_lowlevel();
 106         unpause_graph_tracing();
 107         return 0;
 108 }
 109
 110 static int __init acpi_sleep_setup(char *str)
 111 {
 112         while ((str != NULL) && (*str != '\0')) {
 113                 if (strncmp(str, "s3_bios", 7) == 0)
 114                         acpi_realmode_flags |= 1;
 115                 if (strncmp(str, "s3_mode", 7) == 0)
 116                         acpi_realmode_flags |= 2;
 117                 if (strncmp(str, "s3_beep", 7) == 0)
 118                         acpi_realmode_flags |= 4;
 119 #ifdef CONFIG_HIBERNATION
 120                 if (strncmp(str, "s4_nohwsig", 10) == 0)
 121                         acpi_no_s4_hw_signature();
 122 #endif
 123                 if (strncmp(str, "nonvs", 5) == 0)
 124                         acpi_nvs_nosave();
 125                 if (strncmp(str, "nonvs_s3", 8) == 0)
 126                         acpi_nvs_nosave_s3();
 127                 if (strncmp(str, "old_ordering", 12) == 0)
 128                         acpi_old_suspend_ordering();
 129                 str = strchr(str, ',');
 130                 if (str != NULL)
 131                         str += strspn(str, ", \t");
 132         }
 133         return 1;
 134 }
 135
 136 __setup("acpi_sleep=", acpi_sleep_setup);