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/msr.h>
 20#include <asm/smp.h>
 21
 22#include <linux/ftrace.h>
 23#include "../../realmode/rm/wakeup.h"
 24#include "sleep.h"
 25
 26unsigned long acpi_realmode_flags;
 27
 28#if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
 29static 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 */
 38unsigned 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 */
 49asmlinkage 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 */
 60int 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
154static 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)
187static 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 */
201arch_initcall(init_s4_sigcheck);
202#endif