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

DEFINITIONS

1. x86_acpi_enter_sleep_state
2. x86_acpi_suspend_lowlevel
3. acpi_sleep_setup

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