arch/x86/kernel/acpi/sleep.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * sleep.c - x86-specific ACPI sleep support.
   4  *
   5  *  Copyright (C) 2001-2003 Patrick Mochel
   6  *  Copyright (C) 2001-2003 Pavel Machek <pavel@ucw.cz>
   7  */
   8
   9 #include <linux/acpi.h>
  10 #include <linux/bootmem.h>
  11 #include <linux/memblock.h>
  12 #include <linux/dmi.h>
  13 #include <linux/cpumask.h>
  14 #include <asm/segment.h>
  15 #include <asm/desc.h>
  16 #include <asm/pgtable.h>
  17 #include <asm/cacheflush.h>
  18 #include <asm/realmode.h>
  19
  20 #include <linux/ftrace.h>
  21 #include "../../realmode/rm/wakeup.h"
  22 #include "sleep.h"
  23
  24 unsigned long acpi_realmode_flags;
  25
  26 #if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
  27 static char temp_stack[4096];
  28 #endif
  29
  30 /**
  31  * x86_acpi_enter_sleep_state - enter sleep state
  32  * @state: Sleep state to enter.
  33  *
  34  * Wrapper around acpi_enter_sleep_state() to be called by assmebly.
  35  */
  36 acpi_status asmlinkage __visible x86_acpi_enter_sleep_state(u8 state)
  37 {
  38         return acpi_enter_sleep_state(state);
  39 }
  40
  41 /**
  42  * x86_acpi_suspend_lowlevel - save kernel state
  43  *
  44  * Create an identity mapped page table and copy the wakeup routine to
  45  * low memory.
  46  */
  47 int x86_acpi_suspend_lowlevel(void)
  48 {
  49         struct wakeup_header *header =
  50                 (struct wakeup_header *) __va(real_mode_header->wakeup_header);
  51
  52         if (header->signature != WAKEUP_HEADER_SIGNATURE) {
  53                 printk(KERN_ERR "wakeup header does not match\n");
  54                 return -EINVAL;
  55         }
  56
  57         header->video_mode = saved_video_mode;
  58
  59         header->pmode_behavior = 0;
  60
  61 #ifndef CONFIG_64BIT
  62         native_store_gdt((struct desc_ptr *)&header->pmode_gdt);
  63
  64         /*
  65          * We have to check that we can write back the value, and not
  66          * just read it.  At least on 90 nm Pentium M (Family 6, Model
  67          * 13), reading an invalid MSR is not guaranteed to trap, see
  68          * Erratum X4 in "Intel Pentium M Processor on 90 nm Process
  69          * with 2-MB L2 Cache and Intel® Processor A100 and A110 on 90
  70          * nm process with 512-KB L2 Cache Specification Update".
  71          */
  72         if (!rdmsr_safe(MSR_EFER,
  73                         &header->pmode_efer_low,
  74                         &header->pmode_efer_high) &&
  75             !wrmsr_safe(MSR_EFER,
  76                         header->pmode_efer_low,
  77                         header->pmode_efer_high))
  78                 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
  79 #endif /* !CONFIG_64BIT */
  80
  81         header->pmode_cr0 = read_cr0();
  82         if (__this_cpu_read(cpu_info.cpuid_level) >= 0) {
  83                 header->pmode_cr4 = __read_cr4();
  84                 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4);
  85         }
  86         if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
  87                         &header->pmode_misc_en_low,
  88                         &header->pmode_misc_en_high) &&
  89             !wrmsr_safe(MSR_IA32_MISC_ENABLE,
  90                         header->pmode_misc_en_low,
  91                         header->pmode_misc_en_high))
  92                 header->pmode_behavior |=
  93                         (1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
  94         header->realmode_flags = acpi_realmode_flags;
  95         header->real_magic = 0x12345678;
  96
  97 #ifndef CONFIG_64BIT
  98         header->pmode_entry = (u32)&wakeup_pmode_return;
  99         header->pmode_cr3 = (u32)__pa_symbol(initial_page_table);
 100         saved_magic = 0x12345678;
 101 #else /* CONFIG_64BIT */
 102 #ifdef CONFIG_SMP
 103         initial_stack = (unsigned long)temp_stack + sizeof(temp_stack);
 104         early_gdt_descr.address =
 105                         (unsigned long)get_cpu_gdt_rw(smp_processor_id());
 106         initial_gs = per_cpu_offset(smp_processor_id());
 107 #endif
 108         initial_code = (unsigned long)wakeup_long64;
 109        saved_magic = 0x123456789abcdef0L;
 110 #endif /* CONFIG_64BIT */
 111
 112         /*
 113          * Pause/unpause graph tracing around do_suspend_lowlevel as it has
 114          * inconsistent call/return info after it jumps to the wakeup vector.
 115          */
 116         pause_graph_tracing();
 117         do_suspend_lowlevel();
 118         unpause_graph_tracing();
 119         return 0;
 120 }
 121
 122 static int __init acpi_sleep_setup(char *str)
 123 {
 124         while ((str != NULL) && (*str != '\0')) {
 125                 if (strncmp(str, "s3_bios", 7) == 0)
 126                         acpi_realmode_flags |= 1;
 127                 if (strncmp(str, "s3_mode", 7) == 0)
 128                         acpi_realmode_flags |= 2;
 129                 if (strncmp(str, "s3_beep", 7) == 0)
 130                         acpi_realmode_flags |= 4;
 131 #ifdef CONFIG_HIBERNATION
 132                 if (strncmp(str, "s4_nohwsig", 10) == 0)
 133                         acpi_no_s4_hw_signature();
 134 #endif
 135                 if (strncmp(str, "nonvs", 5) == 0)
 136                         acpi_nvs_nosave();
 137                 if (strncmp(str, "nonvs_s3", 8) == 0)
 138                         acpi_nvs_nosave_s3();
 139                 if (strncmp(str, "old_ordering", 12) == 0)
 140                         acpi_old_suspend_ordering();
 141                 str = strchr(str, ',');
 142                 if (str != NULL)
 143                         str += strspn(str, ", \t");
 144         }
 145         return 1;
 146 }
 147
 148 __setup("acpi_sleep=", acpi_sleep_setup);