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// SPDX-License-Identifier: GPL-2.0-only
/*
* Suspend support specific for i386/x86-64.
*
* Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl>
* Copyright (c) 2002 Pavel Machek <pavel@ucw.cz>
* Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
*/
#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/internal.h>
#include <asm/debugreg.h>
#include <asm/cpu.h>
#include <asm/mmu_context.h>
#include <asm/cpu_device_id.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)
{
struct saved_msr *msr = ctxt->saved_msrs.array;
struct saved_msr *end = msr + ctxt->saved_msrs.num;
while (msr < end) {
msr->valid = !rdmsrl_safe(msr->info.msr_no, &msr->info.reg.q);
msr++;
}
}
static void msr_restore_context(struct saved_context *ctxt)
{
struct saved_msr *msr = ctxt->saved_msrs.array;
struct saved_msr *end = msr + ctxt->saved_msrs.num;
while (msr < end) {
if (msr->valid)
wrmsrl(msr->info.msr_no, msr->info.reg.q);
msr++;
}
}
/**
* __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)
{
#ifdef CONFIG_X86_32
mtrr_save_fixed_ranges(NULL);
#endif
kernel_fpu_begin();
/*
* descriptor tables
*/
store_idt(&ctxt->idt);
/*
* We save it here, but restore it only in the hibernate case.
* For ACPI S3 resume, this is loaded via 'early_gdt_desc' in 64-bit
* mode in "secondary_startup_64". In 32-bit mode it is done via
* 'pmode_gdt' in wakeup_start.
*/
ctxt->gdt_desc.size = GDT_SIZE - 1;
ctxt->gdt_desc.address = (unsigned long)get_cpu_gdt_rw(smp_processor_id());
store_tr(ctxt->tr);
/* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
/*
* segment registers
*/
#ifdef CONFIG_X86_32_LAZY_GS
savesegment(gs, ctxt->gs);
#endif
#ifdef CONFIG_X86_64
savesegment(gs, ctxt->gs);
savesegment(fs, ctxt->fs);
savesegment(ds, ctxt->ds);
savesegment(es, ctxt->es);
rdmsrl(MSR_FS_BASE, ctxt->fs_base);
rdmsrl(MSR_GS_BASE, ctxt->kernelmode_gs_base);
rdmsrl(MSR_KERNEL_GS_BASE, ctxt->usermode_gs_base);
mtrr_save_fixed_ranges(NULL);
rdmsrl(MSR_EFER, ctxt->efer);
#endif
/*
* control registers
*/
ctxt->cr0 = read_cr0();
ctxt->cr2 = read_cr2();
ctxt->cr3 = __read_cr3();
ctxt->cr4 = __read_cr4();
ctxt->misc_enable_saved = !rdmsrl_safe(MSR_IA32_MISC_ENABLE,
&ctxt->misc_enable);
msr_save_context(ctxt);
}
/* Needed by apm.c */
void save_processor_state(void)
{
__save_processor_state(&saved_context);
x86_platform.save_sched_clock_state();
}
#ifdef CONFIG_X86_32
EXPORT_SYMBOL(save_processor_state);
#endif
static void do_fpu_end(void)
{
/*
* Restore FPU regs if necessary.
*/
kernel_fpu_end();
}
static void fix_processor_context(void)
{
int cpu = smp_processor_id();
#ifdef CONFIG_X86_64
struct desc_struct *desc = get_cpu_gdt_rw(cpu);
tss_desc tss;
#endif
/*
* We need to reload TR, which requires that we change the
* GDT entry to indicate "available" first.
*
* XXX: This could probably all be replaced by a call to
* force_reload_TR().
*/
set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
#ifdef CONFIG_X86_64
memcpy(&tss, &desc[GDT_ENTRY_TSS], sizeof(tss_desc));
tss.type = 0x9; /* The available 64-bit TSS (see AMD vol 2, pg 91 */
write_gdt_entry(desc, GDT_ENTRY_TSS, &tss, DESC_TSS);
syscall_init(); /* This sets MSR_*STAR and related */
#else
if (boot_cpu_has(X86_FEATURE_SEP))
enable_sep_cpu();
#endif
load_TR_desc(); /* This does ltr */
load_mm_ldt(current->active_mm); /* This does lldt */
initialize_tlbstate_and_flush();
fpu__resume_cpu();
/* The processor is back on the direct GDT, load back the fixmap */
load_fixmap_gdt(cpu);
}
/**
* __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)
{
struct cpuinfo_x86 *c;
if (ctxt->misc_enable_saved)
wrmsrl(MSR_IA32_MISC_ENABLE, ctxt->misc_enable);
/*
* control registers
*/
/* cr4 was introduced in the Pentium CPU */
#ifdef CONFIG_X86_32
if (ctxt->cr4)
__write_cr4(ctxt->cr4);
#else
/* CONFIG X86_64 */
wrmsrl(MSR_EFER, ctxt->efer);
__write_cr4(ctxt->cr4);
#endif
write_cr3(ctxt->cr3);
write_cr2(ctxt->cr2);
write_cr0(ctxt->cr0);
/* Restore the IDT. */
load_idt(&ctxt->idt);
/*
* Just in case the asm code got us here with the SS, DS, or ES
* out of sync with the GDT, update them.
*/
loadsegment(ss, __KERNEL_DS);
loadsegment(ds, __USER_DS);
loadsegment(es, __USER_DS);
/*
* Restore percpu access. Percpu access can happen in exception
* handlers or in complicated helpers like load_gs_index().
*/
#ifdef CONFIG_X86_64
wrmsrl(MSR_GS_BASE, ctxt->kernelmode_gs_base);
#else
loadsegment(fs, __KERNEL_PERCPU);
loadsegment(gs, __KERNEL_STACK_CANARY);
#endif
/* Restore the TSS, RO GDT, LDT, and usermode-relevant MSRs. */
fix_processor_context();
/*
* Now that we have descriptor tables fully restored and working
* exception handling, restore the usermode segments.
*/
#ifdef CONFIG_X86_64
loadsegment(ds, ctxt->es);
loadsegment(es, ctxt->es);
loadsegment(fs, ctxt->fs);
load_gs_index(ctxt->gs);
/*
* Restore FSBASE and GSBASE after restoring the selectors, since
* restoring the selectors clobbers the bases. Keep in mind
* that MSR_KERNEL_GS_BASE is horribly misnamed.
*/
wrmsrl(MSR_FS_BASE, ctxt->fs_base);
wrmsrl(MSR_KERNEL_GS_BASE, ctxt->usermode_gs_base);
#elif defined(CONFIG_X86_32_LAZY_GS)
loadsegment(gs, ctxt->gs);
#endif
do_fpu_end();
tsc_verify_tsc_adjust(true);
x86_platform.restore_sched_clock_state();
mtrr_bp_restore();
perf_restore_debug_store();
msr_restore_context(ctxt);
c = &cpu_data(smp_processor_id());
if (cpu_has(c, X86_FEATURE_MSR_IA32_FEAT_CTL))
init_ia32_feat_ctl(c);
}
/* Needed by apm.c */
void notrace restore_processor_state(void)
{
__restore_processor_state(&saved_context);
}
#ifdef CONFIG_X86_32
EXPORT_SYMBOL(restore_processor_state);
#endif
#if defined(CONFIG_HIBERNATION) && defined(CONFIG_HOTPLUG_CPU)
static void resume_play_dead(void)
{
play_dead_common();
tboot_shutdown(TB_SHUTDOWN_WFS);
hlt_play_dead();
}
int hibernate_resume_nonboot_cpu_disable(void)
{
void (*play_dead)(void) = smp_ops.play_dead;
int ret;
/*
* Ensure that MONITOR/MWAIT will not be used in the "play dead" loop
* during hibernate image restoration, because it is likely that the
* monitored address will be actually written to at that time and then
* the "dead" CPU will attempt to execute instructions again, but the
* address in its instruction pointer may not be possible to resolve
* any more at that point (the page tables used by it previously may
* have been overwritten by hibernate image data).
*
* First, make sure that we wake up all the potentially disabled SMT
* threads which have been initially brought up and then put into
* mwait/cpuidle sleep.
* Those will be put to proper (not interfering with hibernation
* resume) sleep afterwards, and the resumed kernel will decide itself
* what to do with them.
*/
ret = cpuhp_smt_enable();
if (ret)
return ret;
smp_ops.play_dead = resume_play_dead;
ret = freeze_secondary_cpus(0);
smp_ops.play_dead = play_dead;
return ret;
}
#endif
/*
* When bsp_check() is called in hibernate and suspend, cpu hotplug
* is disabled already. So it's unnessary to handle race condition between
* cpumask query and cpu hotplug.
*/
static int bsp_check(void)
{
if (cpumask_first(cpu_online_mask) != 0) {
pr_warn("CPU0 is offline.\n");
return -ENODEV;
}
return 0;
}
static int bsp_pm_callback(struct notifier_block *nb, unsigned long action,
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