1 files changed, 508 insertions, 0 deletions

diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
new file mode 100644
index 0000000000..63230ff8cf
--- /dev/null
+++ b/arch/x86/power/cpu.c
@@ -0,0 +1,508 @@
+// 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/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)
+{
+	struct saved_msr *msr = ctxt->saved_msrs.array;
+	struct saved_msr *end = msr + ctxt->saved_msrs.num;
+
+	while (msr < end) {
+		if (msr->valid)
+			rdmsrl(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
+	 */
+	savesegment(gs, ctxt->gs);
+#ifdef CONFIG_X86_64
+	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);
+#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);
+#else
+	loadsegment(gs, ctxt->gs);
+#endif
+
+	do_fpu_end();
+	tsc_verify_tsc_adjust(true);
+	x86_platform.restore_sched_clock_state();
+	cache_bp_restore();
+	perf_restore_debug_store();
+
+	c = &cpu_data(smp_processor_id());
+	if (cpu_has(c, X86_FEATURE_MSR_IA32_FEAT_CTL))
+		init_ia32_feat_ctl(c);
+
+	microcode_bsp_resume();
+
+	/*
+	 * This needs to happen after the microcode has been updated upon resume
+	 * because some of the MSRs are "emulated" in microcode.
+	 */
+	msr_restore_context(ctxt);
+}
+
+/* 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 __noreturn 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 unnecessary 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,
+			   void *ptr)
+{
+	int ret = 0;
+
+	switch (action) {
+	case PM_SUSPEND_PREPARE:
+	case PM_HIBERNATION_PREPARE:
+		ret = bsp_check();
+		break;
+	default:
+		break;
+	}
+	return notifier_from_errno(ret);
+}
+
+static int __init bsp_pm_check_init(void)
+{
+	/*
+	 * Set this bsp_pm_callback as lower priority than
+	 * cpu_hotplug_pm_callback. So cpu_hotplug_pm_callback will be called
+	 * earlier to disable cpu hotplug before bsp online check.
+	 */
+	pm_notifier(bsp_pm_callback, -INT_MAX);
+	return 0;
+}
+
+core_initcall(bsp_pm_check_init);
+
+static int msr_build_context(const u32 *msr_id, const int num)
+{
+	struct saved_msrs *saved_msrs = &saved_context.saved_msrs;
+	struct saved_msr *msr_array;
+	int total_num;
+	int i, j;
+
+	total_num = saved_msrs->num + num;
+
+	msr_array = kmalloc_array(total_num, sizeof(struct saved_msr), GFP_KERNEL);
+	if (!msr_array) {
+		pr_err("x86/pm: Can not allocate memory to save/restore MSRs during suspend.\n");
+		return -ENOMEM;
+	}
+
+	if (saved_msrs->array) {
+		/*
+		 * Multiple callbacks can invoke this function, so copy any
+		 * MSR save requests from previous invocations.
+		 */
+		memcpy(msr_array, saved_msrs->array,
+		       sizeof(struct saved_msr) * saved_msrs->num);
+
+		kfree(saved_msrs->array);
+	}
+
+	for (i = saved_msrs->num, j = 0; i < total_num; i++, j++) {
+		u64 dummy;
+
+		msr_array[i].info.msr_no	= msr_id[j];
+		msr_array[i].valid		= !rdmsrl_safe(msr_id[j], &dummy);
+		msr_array[i].info.reg.q		= 0;
+	}
+	saved_msrs->num   = total_num;
+	saved_msrs->array = msr_array;
+
+	return 0;
+}
+
+/*
+ * 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)
+{
+	/* Add any extra MSR ids into this array. */
+	u32 bdw_msr_id[] = { MSR_IA32_THERM_CONTROL };
+
+	pr_info("x86/pm: %s detected, MSR saving is needed during suspending.\n", d->ident);
+	return msr_build_context(bdw_msr_id, ARRAY_SIZE(bdw_msr_id));
+}
+
+static const struct dmi_system_id msr_save_dmi_table[] = {
+	{
+	 .callback = msr_initialize_bdw,
+	 .ident = "BROADWELL BDX_EP",
+	 .matches = {
+		DMI_MATCH(DMI_PRODUCT_NAME, "GRANTLEY"),
+		DMI_MATCH(DMI_PRODUCT_VERSION, "E63448-400"),
+		},
+	},
+	{}
+};
+
+static int msr_save_cpuid_features(const struct x86_cpu_id *c)
+{
+	u32 cpuid_msr_id[] = {
+		MSR_AMD64_CPUID_FN_1,
+	};
+
+	pr_info("x86/pm: family %#hx cpu detected, MSR saving is needed during suspending.\n",
+		c->family);
+
+	return msr_build_context(cpuid_msr_id, ARRAY_SIZE(cpuid_msr_id));
+}
+
+static const struct x86_cpu_id msr_save_cpu_table[] = {
+	X86_MATCH_VENDOR_FAM(AMD, 0x15, &msr_save_cpuid_features),
+	X86_MATCH_VENDOR_FAM(AMD, 0x16, &msr_save_cpuid_features),
+	{}
+};
+
+typedef int (*pm_cpu_match_t)(const struct x86_cpu_id *);
+static int pm_cpu_check(const struct x86_cpu_id *c)
+{
+	const struct x86_cpu_id *m;
+	int ret = 0;
+
+	m = x86_match_cpu(msr_save_cpu_table);
+	if (m) {
+		pm_cpu_match_t fn;
+
+		fn = (pm_cpu_match_t)m->driver_data;
+		ret = fn(m);
+	}
+
+	return ret;
+}
+
+static void pm_save_spec_msr(void)
+{
+	struct msr_enumeration {
+		u32 msr_no;
+		u32 feature;
+	} msr_enum[] = {
+		{ MSR_IA32_SPEC_CTRL,	 X86_FEATURE_MSR_SPEC_CTRL },
+		{ MSR_IA32_TSX_CTRL,	 X86_FEATURE_MSR_TSX_CTRL },
+		{ MSR_TSX_FORCE_ABORT,	 X86_FEATURE_TSX_FORCE_ABORT },
+		{ MSR_IA32_MCU_OPT_CTRL, X86_FEATURE_SRBDS_CTRL },
+		{ MSR_AMD64_LS_CFG,	 X86_FEATURE_LS_CFG_SSBD },
+		{ MSR_AMD64_DE_CFG,	 X86_FEATURE_LFENCE_RDTSC },
+	};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(msr_enum); i++) {
+		if (boot_cpu_has(msr_enum[i].feature))
+			msr_build_context(&msr_enum[i].msr_no, 1);
+	}
+}
+
+static int pm_check_save_msr(void)
+{
+	dmi_check_system(msr_save_dmi_table);
+	pm_cpu_check(msr_save_cpu_table);
+	pm_save_spec_msr();
+
+	return 0;
+}
+
+device_initcall(pm_check_save_msr);