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