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/memblock.h>
  11 #include <linux/dmi.h>
  12 #include <linux/cpumask.h>
  13 #include <linux/pgtable.h>
  14 #include <asm/segment.h>
  15 #include <asm/desc.h>
  16 #include <asm/cacheflush.h>
  17 #include <asm/realmode.h>
  18 #include <asm/hypervisor.h>
  19 #include <asm/smp.h>
  20
  21 #include <linux/ftrace.h>
  22 #include "../../realmode/rm/wakeup.h"
  23 #include "sleep.h"
  24
  25 unsigned long acpi_realmode_flags;
  26
  27 #if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
  28 static char temp_stack[4096];
  29 #endif
  30
  31 /**
  32  * acpi_get_wakeup_address - provide physical address for S3 wakeup
  33  *
  34  * Returns the physical address where the kernel should be resumed after the
  35  * system awakes from S3, e.g. for programming into the firmware waking vector.
  36  */
  37 unsigned long acpi_get_wakeup_address(void)
  38 {
  39         return ((unsigned long)(real_mode_header->wakeup_start));
  40 }
  41
  42 /**
  43  * x86_acpi_enter_sleep_state - enter sleep state
  44  * @state: Sleep state to enter.
  45  *
  46  * Wrapper around acpi_enter_sleep_state() to be called by assembly.
  47  */
  48 asmlinkage acpi_status __visible x86_acpi_enter_sleep_state(u8 state)
  49 {
  50         return acpi_enter_sleep_state(state);
  51 }
  52
  53 /**
  54  * x86_acpi_suspend_lowlevel - save kernel state
  55  *
  56  * Create an identity mapped page table and copy the wakeup routine to
  57  * low memory.
  58  */
  59 int x86_acpi_suspend_lowlevel(void)
  60 {
  61         struct wakeup_header *header =
  62                 (struct wakeup_header *) __va(real_mode_header->wakeup_header);
  63
  64         if (header->signature != WAKEUP_HEADER_SIGNATURE) {
  65                 printk(KERN_ERR "wakeup header does not match\n");
  66                 return -EINVAL;
  67         }
  68
  69         header->video_mode = saved_video_mode;
  70
  71         header->pmode_behavior = 0;
  72
  73 #ifndef CONFIG_64BIT
  74         native_store_gdt((struct desc_ptr *)&header->pmode_gdt);
  75
  76         /*
  77          * We have to check that we can write back the value, and not
  78          * just read it.  At least on 90 nm Pentium M (Family 6, Model
  79          * 13), reading an invalid MSR is not guaranteed to trap, see
  80          * Erratum X4 in "Intel Pentium M Processor on 90 nm Process
  81          * with 2-MB L2 Cache and Intel® Processor A100 and A110 on 90
  82          * nm process with 512-KB L2 Cache Specification Update".
  83          */
  84         if (!rdmsr_safe(MSR_EFER,
  85                         &header->pmode_efer_low,
  86                         &header->pmode_efer_high) &&
  87             !wrmsr_safe(MSR_EFER,
  88                         header->pmode_efer_low,
  89                         header->pmode_efer_high))
  90                 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
  91 #endif /* !CONFIG_64BIT */
  92
  93         header->pmode_cr0 = read_cr0();
  94         if (__this_cpu_read(cpu_info.cpuid_level) >= 0) {
  95                 header->pmode_cr4 = __read_cr4();
  96                 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4);
  97         }
  98         if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
  99                         &header->pmode_misc_en_low,
 100                         &header->pmode_misc_en_high) &&
 101             !wrmsr_safe(MSR_IA32_MISC_ENABLE,
 102                         header->pmode_misc_en_low,
 103                         header->pmode_misc_en_high))
 104                 header->pmode_behavior |=
 105                         (1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
 106         header->realmode_flags = acpi_realmode_flags;
 107         header->real_magic = 0x12345678;
 108
 109 #ifndef CONFIG_64BIT
 110         header->pmode_entry = (u32)&wakeup_pmode_return;
 111         header->pmode_cr3 = (u32)__pa_symbol(initial_page_table);
 112         saved_magic = 0x12345678;
 113 #else /* CONFIG_64BIT */
 114 #ifdef CONFIG_SMP
 115         /*
 116          * As each CPU starts up, it will find its own stack pointer
 117          * from its current_task->thread.sp. Typically that will be
 118          * the idle thread for a newly-started AP, or even the boot
 119          * CPU which will find it set to &init_task in the static
 120          * per-cpu data.
 121          *
 122          * Make the resuming CPU use the temporary stack at startup
 123          * by setting current->thread.sp to point to that. The true
 124          * %rsp will be restored with the rest of the CPU context,
 125          * by do_suspend_lowlevel(). And unwinders don't care about
 126          * the abuse of ->thread.sp because it's a dead variable
 127          * while the thread is running on the CPU anyway; the true
 128          * value is in the actual %rsp register.
 129          */
 130         current->thread.sp = (unsigned long)temp_stack + sizeof(temp_stack);
 131         /*
 132          * Ensure the CPU knows which one it is when it comes back, if
 133          * it isn't in parallel mode and expected to work that out for
 134          * itself.
 135          */
 136         if (!(smpboot_control & STARTUP_PARALLEL_MASK))
 137                 smpboot_control = smp_processor_id();
 138 #endif
 139         initial_code = (unsigned long)wakeup_long64;
 140         saved_magic = 0x123456789abcdef0L;
 141 #endif /* CONFIG_64BIT */
 142
 143         /*
 144          * Pause/unpause graph tracing around do_suspend_lowlevel as it has
 145          * inconsistent call/return info after it jumps to the wakeup vector.
 146          */
 147         pause_graph_tracing();
 148         do_suspend_lowlevel();
 149         unpause_graph_tracing();
 150         return 0;
 151 }
 152
 153 static int __init acpi_sleep_setup(char *str)
 154 {
 155         while ((str != NULL) && (*str != '\0')) {
 156                 if (strncmp(str, "s3_bios", 7) == 0)
 157                         acpi_realmode_flags |= 1;
 158                 if (strncmp(str, "s3_mode", 7) == 0)
 159                         acpi_realmode_flags |= 2;
 160                 if (strncmp(str, "s3_beep", 7) == 0)
 161                         acpi_realmode_flags |= 4;
 162 #ifdef CONFIG_HIBERNATION
 163                 if (strncmp(str, "s4_hwsig", 8) == 0)
 164                         acpi_check_s4_hw_signature = 1;
 165                 if (strncmp(str, "s4_nohwsig", 10) == 0)
 166                         acpi_check_s4_hw_signature = 0;
 167 #endif
 168                 if (strncmp(str, "nonvs", 5) == 0)
 169                         acpi_nvs_nosave();
 170                 if (strncmp(str, "nonvs_s3", 8) == 0)
 171                         acpi_nvs_nosave_s3();
 172                 if (strncmp(str, "old_ordering", 12) == 0)
 173                         acpi_old_suspend_ordering();
 174                 if (strncmp(str, "nobl", 4) == 0)
 175                         acpi_sleep_no_blacklist();
 176                 str = strchr(str, ',');
 177                 if (str != NULL)
 178                         str += strspn(str, ", \t");
 179         }
 180         return 1;
 181 }
 182
 183 __setup("acpi_sleep=", acpi_sleep_setup);
 184
 185 #if defined(CONFIG_HIBERNATION) && defined(CONFIG_HYPERVISOR_GUEST)
 186 static int __init init_s4_sigcheck(void)
 187 {
 188         /*
 189          * If running on a hypervisor, honour the ACPI specification
 190          * by default and trigger a clean reboot when the hardware
 191          * signature in FACS is changed after hibernation.
 192          */
 193         if (acpi_check_s4_hw_signature == -1 &&
 194             !hypervisor_is_type(X86_HYPER_NATIVE))
 195                 acpi_check_s4_hw_signature = 1;
 196
 197         return 0;
 198 }
 199 /* This must happen before acpi_init() which is a subsys initcall */
 200 arch_initcall(init_s4_sigcheck);
 201 #endif