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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/power/cpu.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/power/cpu.c')
-rw-r--r--arch/x86/power/cpu.c544
1 files changed, 544 insertions, 0 deletions
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
new file mode 100644
index 000000000..93ae33248
--- /dev/null
+++ b/arch/x86/power/cpu.c
@@ -0,0 +1,544 @@
+// 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/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();
+ mtrr_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 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;
+#ifdef CONFIG_DEBUG_HOTPLUG_CPU0
+ case PM_RESTORE_PREPARE:
+ /*
+ * When system resumes from hibernation, online CPU0 because
+ * 1. it's required for resume and
+ * 2. the CPU was online before hibernation
+ */
+ if (!cpu_online(0))
+ _debug_hotplug_cpu(0, 1);
+ break;
+ case PM_POST_RESTORE:
+ /*
+ * When a resume really happens, this code won't be called.
+ *
+ * This code is called only when user space hibernation software
+ * prepares for snapshot device during boot time. So we just
+ * call _debug_hotplug_cpu() to restore to CPU0's state prior to
+ * preparing the snapshot device.
+ *
+ * This works for normal boot case in our CPU0 hotplug debug
+ * mode, i.e. CPU0 is offline and user mode hibernation
+ * software initializes during boot time.
+ *
+ * If CPU0 is online and user application accesses snapshot
+ * device after boot time, this will offline CPU0 and user may
+ * see different CPU0 state before and after accessing
+ * the snapshot device. But hopefully this is not a case when
+ * user debugging CPU0 hotplug. Even if users hit this case,
+ * they can easily online CPU0 back.
+ *
+ * To simplify this debug code, we only consider normal boot
+ * case. Otherwise we need to remember CPU0's state and restore
+ * to that state and resolve racy conditions etc.
+ */
+ _debug_hotplug_cpu(0, 0);
+ break;
+#endif
+ 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);