linux/arch/x86/power/cpu.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Suspend support specific for i386/x86-64.
 *
 * Copyright (c) 2007 Rafael J. Wysocki <[email protected]>
 * Copyright (c) 2002 Pavel Machek <[email protected]>
 * Copyright (c) 2001 Patrick Mochel <[email protected]>
 */

#include <linux/suspend.h>
#include <linux/export.h>
#include <linux/smp.h>
#include <linux/perf_event.h>
#include <linux/tboot.h>
#include <linux/dmi.h>
#include <linux/pgtable.h>

#include <asm/proto.h>
#include <asm/mtrr.h>
#include <asm/page.h>
#include <asm/mce.h>
#include <asm/suspend.h>
#include <asm/fpu/api.h>
#include <asm/debugreg.h>
#include <asm/cpu.h>
#include <asm/cacheinfo.h>
#include <asm/mmu_context.h>
#include <asm/cpu_device_id.h>
#include <asm/microcode.h>

#ifdef CONFIG_X86_32
__visible unsigned long saved_context_ebx;
__visible unsigned long saved_context_esp, saved_context_ebp;
__visible unsigned long saved_context_esi, saved_context_edi;
__visible unsigned long saved_context_eflags;
#endif
struct saved_context saved_context;

static void msr_save_context(struct saved_context *ctxt)
{ … }

static void msr_restore_context(struct saved_context *ctxt)
{ … }

/**
 * __save_processor_state() - Save CPU registers before creating a
 *                             hibernation image and before restoring
 *                             the memory state from it
 * @ctxt: Structure to store the registers contents in.
 *
 * NOTE: If there is a CPU register the modification of which by the
 * boot kernel (ie. the kernel used for loading the hibernation image)
 * might affect the operations of the restored target kernel (ie. the one
 * saved in the hibernation image), then its contents must be saved by this
 * function.  In other words, if kernel A is hibernated and different
 * kernel B is used for loading the hibernation image into memory, the
 * kernel A's __save_processor_state() function must save all registers
 * needed by kernel A, so that it can operate correctly after the resume
 * regardless of what kernel B does in the meantime.
 */
static void __save_processor_state(struct saved_context *ctxt)
{ … }

/* Needed by apm.c */
void save_processor_state(void)
{ … }
#ifdef CONFIG_X86_32
EXPORT_SYMBOL(save_processor_state);
#endif

static void do_fpu_end(void)
{ … }

static void fix_processor_context(void)
{ … }

/**
 * __restore_processor_state() - Restore the contents of CPU registers saved
 *                               by __save_processor_state()
 * @ctxt: Structure to load the registers contents from.
 *
 * The asm code that gets us here will have restored a usable GDT, although
 * it will be pointing to the wrong alias.
 */
static void notrace __restore_processor_state(struct saved_context *ctxt)
{ … }

/* Needed by apm.c */
void notrace restore_processor_state(void)
{ … }
#ifdef CONFIG_X86_32
EXPORT_SYMBOL(restore_processor_state);
#endif

#if defined(CONFIG_HIBERNATION) && defined(CONFIG_HOTPLUG_CPU)
static void __noreturn resume_play_dead(void)
{ … }

int hibernate_resume_nonboot_cpu_disable(void)
{ … }
#endif

/*
 * When bsp_check() is called in hibernate and suspend, cpu hotplug
 * is disabled already. So it's unnecessary to handle race condition between
 * cpumask query and cpu hotplug.
 */
static int bsp_check(void)
{ … }

static int bsp_pm_callback(struct notifier_block *nb, unsigned long action,
			   void *ptr)
{ … }

static int __init bsp_pm_check_init(void)
{ … }

core_initcall(bsp_pm_check_init);

static int msr_build_context(const u32 *msr_id, const int num)
{ … }

/*
 * The following sections are a quirk framework for problematic BIOSen:
 * Sometimes MSRs are modified by the BIOSen after suspended to
 * RAM, this might cause unexpected behavior after wakeup.
 * Thus we save/restore these specified MSRs across suspend/resume
 * in order to work around it.
 *
 * For any further problematic BIOSen/platforms,
 * please add your own function similar to msr_initialize_bdw.
 */
static int msr_initialize_bdw(const struct dmi_system_id *d)
{ … }

static const struct dmi_system_id msr_save_dmi_table[] = …;

static int msr_save_cpuid_features(const struct x86_cpu_id *c)
{ … }

static const struct x86_cpu_id msr_save_cpu_table[] = …;

pm_cpu_match_t;
static int pm_cpu_check(const struct x86_cpu_id *c)
{ … }

static void pm_save_spec_msr(void)
{ … }

static int pm_check_save_msr(void)
{ … }

device_initcall(pm_check_save_msr);