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/msr.h> 20 #include <asm/smp.h> 21 22 #include <linux/ftrace.h> 23 #include "../../realmode/rm/wakeup.h" 24 #include "sleep.h" 25 26 unsigned long acpi_realmode_flags; 27 28 #if defined(CONFIG_SMP) && defined(CONFIG_64BIT) 29 static char temp_stack[4096]; 30 #endif 31 32 /** 33 * acpi_get_wakeup_address - provide physical address for S3 wakeup 34 * 35 * Returns the physical address where the kernel should be resumed after the 36 * system awakes from S3, e.g. for programming into the firmware waking vector. 37 */ 38 unsigned long acpi_get_wakeup_address(void) 39 { 40 return ((unsigned long)(real_mode_header->wakeup_start)); 41 } 42 43 /** 44 * x86_acpi_enter_sleep_state - enter sleep state 45 * @state: Sleep state to enter. 46 * 47 * Wrapper around acpi_enter_sleep_state() to be called by assembly. 48 */ 49 asmlinkage acpi_status __visible x86_acpi_enter_sleep_state(u8 state) 50 { 51 return acpi_enter_sleep_state(state); 52 } 53 54 /** 55 * x86_acpi_suspend_lowlevel - save kernel state 56 * 57 * Create an identity mapped page table and copy the wakeup routine to 58 * low memory. 59 */ 60 int x86_acpi_suspend_lowlevel(void) 61 { 62 struct wakeup_header *header = 63 (struct wakeup_header *) __va(real_mode_header->wakeup_header); 64 65 if (header->signature != WAKEUP_HEADER_SIGNATURE) { 66 printk(KERN_ERR "wakeup header does not match\n"); 67 return -EINVAL; 68 } 69 70 header->video_mode = saved_video_mode; 71 72 header->pmode_behavior = 0; 73 74 #ifndef CONFIG_64BIT 75 native_store_gdt((struct desc_ptr *)&header->pmode_gdt); 76 77 /* 78 * We have to check that we can write back the value, and not 79 * just read it. At least on 90 nm Pentium M (Family 6, Model 80 * 13), reading an invalid MSR is not guaranteed to trap, see 81 * Erratum X4 in "Intel Pentium M Processor on 90 nm Process 82 * with 2-MB L2 Cache and Intel® Processor A100 and A110 on 90 83 * nm process with 512-KB L2 Cache Specification Update". 84 */ 85 if (!rdmsr_safe(MSR_EFER, 86 &header->pmode_efer_low, 87 &header->pmode_efer_high) && 88 !wrmsr_safe(MSR_EFER, 89 header->pmode_efer_low, 90 header->pmode_efer_high)) 91 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER); 92 #endif /* !CONFIG_64BIT */ 93 94 header->pmode_cr0 = read_cr0(); 95 if (__this_cpu_read(cpu_info.cpuid_level) >= 0) { 96 header->pmode_cr4 = __read_cr4(); 97 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4); 98 } 99 if (!rdmsr_safe(MSR_IA32_MISC_ENABLE, 100 &header->pmode_misc_en_low, 101 &header->pmode_misc_en_high) && 102 !wrmsr_safe(MSR_IA32_MISC_ENABLE, 103 header->pmode_misc_en_low, 104 header->pmode_misc_en_high)) 105 header->pmode_behavior |= 106 (1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE); 107 header->realmode_flags = acpi_realmode_flags; 108 header->real_magic = 0x12345678; 109 110 #ifndef CONFIG_64BIT 111 header->pmode_entry = (u32)&wakeup_pmode_return; 112 header->pmode_cr3 = (u32)__pa_symbol(initial_page_table); 113 saved_magic = 0x12345678; 114 #else /* CONFIG_64BIT */ 115 #ifdef CONFIG_SMP 116 /* 117 * As each CPU starts up, it will find its own stack pointer 118 * from its current_task->thread.sp. Typically that will be 119 * the idle thread for a newly-started AP, or even the boot 120 * CPU which will find it set to &init_task in the static 121 * per-cpu data. 122 * 123 * Make the resuming CPU use the temporary stack at startup 124 * by setting current->thread.sp to point to that. The true 125 * %rsp will be restored with the rest of the CPU context, 126 * by do_suspend_lowlevel(). And unwinders don't care about 127 * the abuse of ->thread.sp because it's a dead variable 128 * while the thread is running on the CPU anyway; the true 129 * value is in the actual %rsp register. 130 */ 131 current->thread.sp = (unsigned long)temp_stack + sizeof(temp_stack); 132 /* 133 * Ensure the CPU knows which one it is when it comes back, if 134 * it isn't in parallel mode and expected to work that out for 135 * itself. 136 */ 137 if (!(smpboot_control & STARTUP_PARALLEL_MASK)) 138 smpboot_control = smp_processor_id(); 139 #endif 140 initial_code = (unsigned long)wakeup_long64; 141 saved_magic = 0x123456789abcdef0L; 142 #endif /* CONFIG_64BIT */ 143 144 /* 145 * Pause/unpause graph tracing around do_suspend_lowlevel as it has 146 * inconsistent call/return info after it jumps to the wakeup vector. 147 */ 148 pause_graph_tracing(); 149 do_suspend_lowlevel(); 150 unpause_graph_tracing(); 151 return 0; 152 } 153 154 static int __init acpi_sleep_setup(char *str) 155 { 156 while ((str != NULL) && (*str != '\0')) { 157 if (strncmp(str, "s3_bios", 7) == 0) 158 acpi_realmode_flags |= 1; 159 if (strncmp(str, "s3_mode", 7) == 0) 160 acpi_realmode_flags |= 2; 161 if (strncmp(str, "s3_beep", 7) == 0) 162 acpi_realmode_flags |= 4; 163 #ifdef CONFIG_HIBERNATION 164 if (strncmp(str, "s4_hwsig", 8) == 0) 165 acpi_check_s4_hw_signature = 1; 166 if (strncmp(str, "s4_nohwsig", 10) == 0) 167 acpi_check_s4_hw_signature = 0; 168 #endif 169 if (strncmp(str, "nonvs", 5) == 0) 170 acpi_nvs_nosave(); 171 if (strncmp(str, "nonvs_s3", 8) == 0) 172 acpi_nvs_nosave_s3(); 173 if (strncmp(str, "old_ordering", 12) == 0) 174 acpi_old_suspend_ordering(); 175 if (strncmp(str, "nobl", 4) == 0) 176 acpi_sleep_no_blacklist(); 177 str = strchr(str, ','); 178 if (str != NULL) 179 str += strspn(str, ", \t"); 180 } 181 return 1; 182 } 183 184 __setup("acpi_sleep=", acpi_sleep_setup); 185 186 #if defined(CONFIG_HIBERNATION) && defined(CONFIG_HYPERVISOR_GUEST) 187 static int __init init_s4_sigcheck(void) 188 { 189 /* 190 * If running on a hypervisor, honour the ACPI specification 191 * by default and trigger a clean reboot when the hardware 192 * signature in FACS is changed after hibernation. 193 */ 194 if (acpi_check_s4_hw_signature == -1 && 195 !hypervisor_is_type(X86_HYPER_NATIVE)) 196 acpi_check_s4_hw_signature = 1; 197 198 return 0; 199 } 200 /* This must happen before acpi_init() which is a subsys initcall */ 201 arch_initcall(init_s4_sigcheck); 202 #endif 203