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 202