diff options
Diffstat (limited to 'arch/x86/power/cpu.c')
| -rw-r--r-- | arch/x86/power/cpu.c | 547 |
1 files changed, 547 insertions, 0 deletions
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c new file mode 100644 index 000000000..4e4e76ecd --- /dev/null +++ b/arch/x86/power/cpu.c @@ -0,0 +1,547 @@ +// 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> +#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 + */ +#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(); + + 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 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, + 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); |