diff options
Diffstat (limited to 'arch/x86/kernel/cpu/microcode/core.c')
| -rw-r--r-- | arch/x86/kernel/cpu/microcode/core.c | 926 |
1 files changed, 926 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c new file mode 100644 index 000000000000..68049f171860 --- /dev/null +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -0,0 +1,926 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * CPU Microcode Update Driver for Linux + * + * Copyright (C) 2000-2006 Tigran Aivazian <aivazian.tigran@gmail.com> + * 2006 Shaohua Li <shaohua.li@intel.com> + * 2013-2016 Borislav Petkov <bp@alien8.de> + * + * X86 CPU microcode early update for Linux: + * + * Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com> + * H Peter Anvin" <hpa@zytor.com> + * (C) 2015 Borislav Petkov <bp@alien8.de> + * + * This driver allows to upgrade microcode on x86 processors. + */ + +#define pr_fmt(fmt) "microcode: " fmt + +#include <linux/stop_machine.h> +#include <linux/device/faux.h> +#include <linux/syscore_ops.h> +#include <linux/miscdevice.h> +#include <linux/capability.h> +#include <linux/firmware.h> +#include <linux/cpumask.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/mutex.h> +#include <linux/cpu.h> +#include <linux/nmi.h> +#include <linux/fs.h> +#include <linux/mm.h> + +#include <asm/apic.h> +#include <asm/cpu_device_id.h> +#include <asm/perf_event.h> +#include <asm/processor.h> +#include <asm/cmdline.h> +#include <asm/msr.h> +#include <asm/setup.h> + +#include "internal.h" + +static struct microcode_ops *microcode_ops; +static bool dis_ucode_ldr; + +bool force_minrev = IS_ENABLED(CONFIG_MICROCODE_LATE_FORCE_MINREV); + +/* + * Those below should be behind CONFIG_MICROCODE_DBG ifdeffery but in + * order to not uglify the code with ifdeffery and use IS_ENABLED() + * instead, leave them in. When microcode debugging is not enabled, + * those are meaningless anyway. + */ +/* base microcode revision for debugging */ +u32 base_rev; +u32 microcode_rev[NR_CPUS] = {}; + +/* + * Synchronization. + * + * All non cpu-hotplug-callback call sites use: + * + * - cpus_read_lock/unlock() to synchronize with + * the cpu-hotplug-callback call sites. + * + * We guarantee that only a single cpu is being + * updated at any particular moment of time. + */ +struct ucode_cpu_info ucode_cpu_info[NR_CPUS]; + +/* + * Those patch levels cannot be updated to newer ones and thus should be final. + */ +static u32 final_levels[] = { + 0x01000098, + 0x0100009f, + 0x010000af, + 0, /* T-101 terminator */ +}; + +struct early_load_data early_data; + +/* + * Check the current patch level on this CPU. + * + * Returns: + * - true: if update should stop + * - false: otherwise + */ +static bool amd_check_current_patch_level(void) +{ + u32 lvl, dummy, i; + u32 *levels; + + if (x86_cpuid_vendor() != X86_VENDOR_AMD) + return false; + + native_rdmsr(MSR_AMD64_PATCH_LEVEL, lvl, dummy); + + levels = final_levels; + + for (i = 0; levels[i]; i++) { + if (lvl == levels[i]) + return true; + } + return false; +} + +bool __init microcode_loader_disabled(void) +{ + if (dis_ucode_ldr) + return true; + + /* + * Disable when: + * + * 1) The CPU does not support CPUID. + * + * 2) Bit 31 in CPUID[1]:ECX is clear + * The bit is reserved for hypervisor use. This is still not + * completely accurate as XEN PV guests don't see that CPUID bit + * set, but that's good enough as they don't land on the BSP + * path anyway. + * + * 3) Certain AMD patch levels are not allowed to be + * overwritten. + */ + if (!cpuid_feature() || + ((native_cpuid_ecx(1) & BIT(31)) && + !IS_ENABLED(CONFIG_MICROCODE_DBG)) || + amd_check_current_patch_level()) + dis_ucode_ldr = true; + + return dis_ucode_ldr; +} + +static void __init early_parse_cmdline(void) +{ + char cmd_buf[64] = {}; + char *s, *p = cmd_buf; + + if (cmdline_find_option(boot_command_line, "microcode", cmd_buf, sizeof(cmd_buf)) > 0) { + while ((s = strsep(&p, ","))) { + if (IS_ENABLED(CONFIG_MICROCODE_DBG)) { + if (strstr(s, "base_rev=")) { + /* advance to the option arg */ + strsep(&s, "="); + if (kstrtouint(s, 16, &base_rev)) { ; } + } + } + + if (!strcmp("force_minrev", s)) + force_minrev = true; + + if (!strcmp(s, "dis_ucode_ldr")) + dis_ucode_ldr = true; + } + } + + /* old, compat option */ + if (cmdline_find_option_bool(boot_command_line, "dis_ucode_ldr") > 0) + dis_ucode_ldr = true; +} + +void __init load_ucode_bsp(void) +{ + unsigned int cpuid_1_eax; + bool intel = true; + + early_parse_cmdline(); + + if (microcode_loader_disabled()) + return; + + cpuid_1_eax = native_cpuid_eax(1); + + switch (x86_cpuid_vendor()) { + case X86_VENDOR_INTEL: + if (x86_family(cpuid_1_eax) < 6) + return; + break; + + case X86_VENDOR_AMD: + if (x86_family(cpuid_1_eax) < 0x10) + return; + intel = false; + break; + + default: + return; + } + + if (intel) + load_ucode_intel_bsp(&early_data); + else + load_ucode_amd_bsp(&early_data, cpuid_1_eax); +} + +void load_ucode_ap(void) +{ + unsigned int cpuid_1_eax; + + /* + * Can't use microcode_loader_disabled() here - .init section + * hell. It doesn't have to either - the BSP variant must've + * parsed cmdline already anyway. + */ + if (dis_ucode_ldr) + return; + + cpuid_1_eax = native_cpuid_eax(1); + + switch (x86_cpuid_vendor()) { + case X86_VENDOR_INTEL: + if (x86_family(cpuid_1_eax) >= 6) + load_ucode_intel_ap(); + break; + case X86_VENDOR_AMD: + if (x86_family(cpuid_1_eax) >= 0x10) + load_ucode_amd_ap(cpuid_1_eax); + break; + default: + break; + } +} + +struct cpio_data __init find_microcode_in_initrd(const char *path) +{ +#ifdef CONFIG_BLK_DEV_INITRD + unsigned long start = 0; + size_t size; + +#ifdef CONFIG_X86_32 + size = boot_params.hdr.ramdisk_size; + /* Early load on BSP has a temporary mapping. */ + if (size) + start = initrd_start_early; + +#else /* CONFIG_X86_64 */ + size = (unsigned long)boot_params.ext_ramdisk_size << 32; + size |= boot_params.hdr.ramdisk_size; + + if (size) { + start = (unsigned long)boot_params.ext_ramdisk_image << 32; + start |= boot_params.hdr.ramdisk_image; + start += PAGE_OFFSET; + } +#endif + + /* + * Fixup the start address: after reserve_initrd() runs, initrd_start + * has the virtual address of the beginning of the initrd. It also + * possibly relocates the ramdisk. In either case, initrd_start contains + * the updated address so use that instead. + */ + if (initrd_start) + start = initrd_start; + + return find_cpio_data(path, (void *)start, size, NULL); +#else /* !CONFIG_BLK_DEV_INITRD */ + return (struct cpio_data){ NULL, 0, "" }; +#endif +} + +static void reload_early_microcode(unsigned int cpu) +{ + int vendor, family; + + vendor = x86_cpuid_vendor(); + family = x86_cpuid_family(); + + switch (vendor) { + case X86_VENDOR_INTEL: + if (family >= 6) + reload_ucode_intel(); + break; + case X86_VENDOR_AMD: + if (family >= 0x10) + reload_ucode_amd(cpu); + break; + default: + break; + } +} + +/* fake device for request_firmware */ +static struct faux_device *microcode_fdev; + +#ifdef CONFIG_MICROCODE_LATE_LOADING +/* + * Late loading dance. Why the heavy-handed stomp_machine effort? + * + * - HT siblings must be idle and not execute other code while the other sibling + * is loading microcode in order to avoid any negative interactions caused by + * the loading. + * + * - In addition, microcode update on the cores must be serialized until this + * requirement can be relaxed in the future. Right now, this is conservative + * and good. + */ +enum sibling_ctrl { + /* Spinwait with timeout */ + SCTRL_WAIT, + /* Invoke the microcode_apply() callback */ + SCTRL_APPLY, + /* Proceed without invoking the microcode_apply() callback */ + SCTRL_DONE, +}; + +struct microcode_ctrl { + enum sibling_ctrl ctrl; + enum ucode_state result; + unsigned int ctrl_cpu; + bool nmi_enabled; +}; + +DEFINE_STATIC_KEY_FALSE(microcode_nmi_handler_enable); +static DEFINE_PER_CPU(struct microcode_ctrl, ucode_ctrl); +static atomic_t late_cpus_in, offline_in_nmi; +static unsigned int loops_per_usec; +static cpumask_t cpu_offline_mask; + +static noinstr bool wait_for_cpus(atomic_t *cnt) +{ + unsigned int timeout, loops; + + WARN_ON_ONCE(raw_atomic_dec_return(cnt) < 0); + + for (timeout = 0; timeout < USEC_PER_SEC; timeout++) { + if (!raw_atomic_read(cnt)) + return true; + + for (loops = 0; loops < loops_per_usec; loops++) + cpu_relax(); + + /* If invoked directly, tickle the NMI watchdog */ + if (!microcode_ops->use_nmi && !(timeout % USEC_PER_MSEC)) { + instrumentation_begin(); + touch_nmi_watchdog(); + instrumentation_end(); + } + } + /* Prevent the late comers from making progress and let them time out */ + raw_atomic_inc(cnt); + return false; +} + +static noinstr bool wait_for_ctrl(void) +{ + unsigned int timeout, loops; + + for (timeout = 0; timeout < USEC_PER_SEC; timeout++) { + if (raw_cpu_read(ucode_ctrl.ctrl) != SCTRL_WAIT) + return true; + + for (loops = 0; loops < loops_per_usec; loops++) + cpu_relax(); + + /* If invoked directly, tickle the NMI watchdog */ + if (!microcode_ops->use_nmi && !(timeout % USEC_PER_MSEC)) { + instrumentation_begin(); + touch_nmi_watchdog(); + instrumentation_end(); + } + } + return false; +} + +/* + * Protected against instrumentation up to the point where the primary + * thread completed the update. See microcode_nmi_handler() for details. + */ +static noinstr bool load_secondary_wait(unsigned int ctrl_cpu) +{ + /* Initial rendezvous to ensure that all CPUs have arrived */ + if (!wait_for_cpus(&late_cpus_in)) { + raw_cpu_write(ucode_ctrl.result, UCODE_TIMEOUT); + return false; + } + + /* + * Wait for primary threads to complete. If one of them hangs due + * to the update, there is no way out. This is non-recoverable + * because the CPU might hold locks or resources and confuse the + * scheduler, watchdogs etc. There is no way to safely evacuate the + * machine. + */ + if (wait_for_ctrl()) + return true; + + instrumentation_begin(); + panic("Microcode load: Primary CPU %d timed out\n", ctrl_cpu); + instrumentation_end(); +} + +/* + * Protected against instrumentation up to the point where the primary + * thread completed the update. See microcode_nmi_handler() for details. + */ +static noinstr void load_secondary(unsigned int cpu) +{ + unsigned int ctrl_cpu = raw_cpu_read(ucode_ctrl.ctrl_cpu); + enum ucode_state ret; + + if (!load_secondary_wait(ctrl_cpu)) { + instrumentation_begin(); + pr_err_once("load: %d CPUs timed out\n", + atomic_read(&late_cpus_in) - 1); + instrumentation_end(); + return; + } + + /* Primary thread completed. Allow to invoke instrumentable code */ + instrumentation_begin(); + /* + * If the primary succeeded then invoke the apply() callback, + * otherwise copy the state from the primary thread. + */ + if (this_cpu_read(ucode_ctrl.ctrl) == SCTRL_APPLY) + ret = microcode_ops->apply_microcode(cpu); + else + ret = per_cpu(ucode_ctrl.result, ctrl_cpu); + + this_cpu_write(ucode_ctrl.result, ret); + this_cpu_write(ucode_ctrl.ctrl, SCTRL_DONE); + instrumentation_end(); +} + +static void __load_primary(unsigned int cpu) +{ + struct cpumask *secondaries = topology_sibling_cpumask(cpu); + enum sibling_ctrl ctrl; + enum ucode_state ret; + unsigned int sibling; + + /* Initial rendezvous to ensure that all CPUs have arrived */ + if (!wait_for_cpus(&late_cpus_in)) { + this_cpu_write(ucode_ctrl.result, UCODE_TIMEOUT); + pr_err_once("load: %d CPUs timed out\n", atomic_read(&late_cpus_in) - 1); + return; + } + + ret = microcode_ops->apply_microcode(cpu); + this_cpu_write(ucode_ctrl.result, ret); + this_cpu_write(ucode_ctrl.ctrl, SCTRL_DONE); + + /* + * If the update was successful, let the siblings run the apply() + * callback. If not, tell them it's done. This also covers the + * case where the CPU has uniform loading at package or system + * scope implemented but does not advertise it. + */ + if (ret == UCODE_UPDATED || ret == UCODE_OK) + ctrl = SCTRL_APPLY; + else + ctrl = SCTRL_DONE; + + for_each_cpu(sibling, secondaries) { + if (sibling != cpu) + per_cpu(ucode_ctrl.ctrl, sibling) = ctrl; + } +} + +static bool kick_offline_cpus(unsigned int nr_offl) +{ + unsigned int cpu, timeout; + + for_each_cpu(cpu, &cpu_offline_mask) { + /* Enable the rendezvous handler and send NMI */ + per_cpu(ucode_ctrl.nmi_enabled, cpu) = true; + apic_send_nmi_to_offline_cpu(cpu); + } + + /* Wait for them to arrive */ + for (timeout = 0; timeout < (USEC_PER_SEC / 2); timeout++) { + if (atomic_read(&offline_in_nmi) == nr_offl) + return true; + udelay(1); + } + /* Let the others time out */ + return false; +} + +static void release_offline_cpus(void) +{ + unsigned int cpu; + + for_each_cpu(cpu, &cpu_offline_mask) + per_cpu(ucode_ctrl.ctrl, cpu) = SCTRL_DONE; +} + +static void load_primary(unsigned int cpu) +{ + unsigned int nr_offl = cpumask_weight(&cpu_offline_mask); + bool proceed = true; + + /* Kick soft-offlined SMT siblings if required */ + if (!cpu && nr_offl) + proceed = kick_offline_cpus(nr_offl); + + /* If the soft-offlined CPUs did not respond, abort */ + if (proceed) + __load_primary(cpu); + + /* Unconditionally release soft-offlined SMT siblings if required */ + if (!cpu && nr_offl) + release_offline_cpus(); +} + +/* + * Minimal stub rendezvous handler for soft-offlined CPUs which participate + * in the NMI rendezvous to protect against a concurrent NMI on affected + * CPUs. + */ +void noinstr microcode_offline_nmi_handler(void) +{ + if (!raw_cpu_read(ucode_ctrl.nmi_enabled)) + return; + raw_cpu_write(ucode_ctrl.nmi_enabled, false); + raw_cpu_write(ucode_ctrl.result, UCODE_OFFLINE); + raw_atomic_inc(&offline_in_nmi); + wait_for_ctrl(); +} + +static noinstr bool microcode_update_handler(void) +{ + unsigned int cpu = raw_smp_processor_id(); + + if (raw_cpu_read(ucode_ctrl.ctrl_cpu) == cpu) { + instrumentation_begin(); + load_primary(cpu); + instrumentation_end(); + } else { + load_secondary(cpu); + } + + instrumentation_begin(); + touch_nmi_watchdog(); + instrumentation_end(); + + return true; +} + +/* + * Protection against instrumentation is required for CPUs which are not + * safe against an NMI which is delivered to the secondary SMT sibling + * while the primary thread updates the microcode. Instrumentation can end + * up in #INT3, #DB and #PF. The IRET from those exceptions reenables NMI + * which is the opposite of what the NMI rendezvous is trying to achieve. + * + * The primary thread is safe versus instrumentation as the actual + * microcode update handles this correctly. It's only the sibling code + * path which must be NMI safe until the primary thread completed the + * update. + */ +bool noinstr microcode_nmi_handler(void) +{ + if (!raw_cpu_read(ucode_ctrl.nmi_enabled)) + return false; + + raw_cpu_write(ucode_ctrl.nmi_enabled, false); + return microcode_update_handler(); +} + +static int load_cpus_stopped(void *unused) +{ + if (microcode_ops->use_nmi) { + /* Enable the NMI handler and raise NMI */ + this_cpu_write(ucode_ctrl.nmi_enabled, true); + apic->send_IPI(smp_processor_id(), NMI_VECTOR); + } else { + /* Just invoke the handler directly */ + microcode_update_handler(); + } + return 0; +} + +static int load_late_stop_cpus(bool is_safe) +{ + unsigned int cpu, updated = 0, failed = 0, timedout = 0, siblings = 0; + unsigned int nr_offl, offline = 0; + int old_rev = boot_cpu_data.microcode; + struct cpuinfo_x86 prev_info; + + if (!is_safe) { + pr_err("Late microcode loading without minimal revision check.\n"); + pr_err("You should switch to early loading, if possible.\n"); + } + + /* + * Pre-load the microcode image into a staging device. This + * process is preemptible and does not require stopping CPUs. + * Successful staging simplifies the subsequent late-loading + * process, reducing rendezvous time. + * + * Even if the transfer fails, the update will proceed as usual. + */ + if (microcode_ops->use_staging) + microcode_ops->stage_microcode(); + + atomic_set(&late_cpus_in, num_online_cpus()); + atomic_set(&offline_in_nmi, 0); + loops_per_usec = loops_per_jiffy / (TICK_NSEC / 1000); + + /* + * Take a snapshot before the microcode update in order to compare and + * check whether any bits changed after an update. + */ + store_cpu_caps(&prev_info); + + if (microcode_ops->use_nmi) + static_branch_enable_cpuslocked(µcode_nmi_handler_enable); + + stop_machine_cpuslocked(load_cpus_stopped, NULL, cpu_online_mask); + + if (microcode_ops->use_nmi) + static_branch_disable_cpuslocked(µcode_nmi_handler_enable); + + /* Analyze the results */ + for_each_cpu_and(cpu, cpu_present_mask, &cpus_booted_once_mask) { + switch (per_cpu(ucode_ctrl.result, cpu)) { + case UCODE_UPDATED: updated++; break; + case UCODE_TIMEOUT: timedout++; break; + case UCODE_OK: siblings++; break; + case UCODE_OFFLINE: offline++; break; + default: failed++; break; + } + } + + if (microcode_ops->finalize_late_load) + microcode_ops->finalize_late_load(!updated); + + if (!updated) { + /* Nothing changed. */ + if (!failed && !timedout) + return 0; + + nr_offl = cpumask_weight(&cpu_offline_mask); + if (offline < nr_offl) { + pr_warn("%u offline siblings did not respond.\n", + nr_offl - atomic_read(&offline_in_nmi)); + return -EIO; + } + pr_err("update failed: %u CPUs failed %u CPUs timed out\n", + failed, timedout); + return -EIO; + } + + if (!is_safe || failed || timedout) + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); + + pr_info("load: updated on %u primary CPUs with %u siblings\n", updated, siblings); + if (failed || timedout) { + pr_err("load incomplete. %u CPUs timed out or failed\n", + num_online_cpus() - (updated + siblings)); + } + pr_info("revision: 0x%x -> 0x%x\n", old_rev, boot_cpu_data.microcode); + microcode_check(&prev_info); + + return updated + siblings == num_online_cpus() ? 0 : -EIO; +} + +/* + * This function does two things: + * + * 1) Ensure that all required CPUs which are present and have been booted + * once are online. + * + * To pass this check, all primary threads must be online. + * + * If the microcode load is not safe against NMI then all SMT threads + * must be online as well because they still react to NMIs when they are + * soft-offlined and parked in one of the play_dead() variants. So if a + * NMI hits while the primary thread updates the microcode the resulting + * behaviour is undefined. The default play_dead() implementation on + * modern CPUs uses MWAIT, which is also not guaranteed to be safe + * against a microcode update which affects MWAIT. + * + * As soft-offlined CPUs still react on NMIs, the SMT sibling + * restriction can be lifted when the vendor driver signals to use NMI + * for rendezvous and the APIC provides a mechanism to send an NMI to a + * soft-offlined CPU. The soft-offlined CPUs are then able to + * participate in the rendezvous in a trivial stub handler. + * + * 2) Initialize the per CPU control structure and create a cpumask + * which contains "offline"; secondary threads, so they can be handled + * correctly by a control CPU. + */ +static bool setup_cpus(void) +{ + struct microcode_ctrl ctrl = { .ctrl = SCTRL_WAIT, .result = -1, }; + bool allow_smt_offline; + unsigned int cpu; + + allow_smt_offline = microcode_ops->nmi_safe || + (microcode_ops->use_nmi && apic->nmi_to_offline_cpu); + + cpumask_clear(&cpu_offline_mask); + + for_each_cpu_and(cpu, cpu_present_mask, &cpus_booted_once_mask) { + /* + * Offline CPUs sit in one of the play_dead() functions + * with interrupts disabled, but they still react on NMIs + * and execute arbitrary code. Also MWAIT being updated + * while the offline CPU sits there is not necessarily safe + * on all CPU variants. + * + * Mark them in the offline_cpus mask which will be handled + * by CPU0 later in the update process. + * + * Ensure that the primary thread is online so that it is + * guaranteed that all cores are updated. + */ + if (!cpu_online(cpu)) { + if (topology_is_primary_thread(cpu) || !allow_smt_offline) { + pr_err("CPU %u not online, loading aborted\n", cpu); + return false; + } + cpumask_set_cpu(cpu, &cpu_offline_mask); + per_cpu(ucode_ctrl, cpu) = ctrl; + continue; + } + + /* + * Initialize the per CPU state. This is core scope for now, + * but prepared to take package or system scope into account. + */ + ctrl.ctrl_cpu = cpumask_first(topology_sibling_cpumask(cpu)); + per_cpu(ucode_ctrl, cpu) = ctrl; + } + return true; +} + +static int load_late_locked(void) +{ + if (!setup_cpus()) + return -EBUSY; + + switch (microcode_ops->request_microcode_fw(0, µcode_fdev->dev)) { + case UCODE_NEW: + return load_late_stop_cpus(false); + case UCODE_NEW_SAFE: + return load_late_stop_cpus(true); + case UCODE_NFOUND: + return -ENOENT; + case UCODE_OK: + return 0; + default: + return -EBADFD; + } +} + +static ssize_t reload_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + unsigned long val; + ssize_t ret; + + ret = kstrtoul(buf, 0, &val); + if (ret || val != 1) + return -EINVAL; + + cpus_read_lock(); + ret = load_late_locked(); + cpus_read_unlock(); + + return ret ? : size; +} + +static DEVICE_ATTR_WO(reload); +#endif + +static ssize_t version_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct ucode_cpu_info *uci = ucode_cpu_info + dev->id; + + return sprintf(buf, "0x%x\n", uci->cpu_sig.rev); +} + +static ssize_t processor_flags_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct ucode_cpu_info *uci = ucode_cpu_info + dev->id; + + return sprintf(buf, "0x%x\n", uci->cpu_sig.pf); +} + +static DEVICE_ATTR_RO(version); +static DEVICE_ATTR_RO(processor_flags); + +static struct attribute *mc_default_attrs[] = { + &dev_attr_version.attr, + &dev_attr_processor_flags.attr, + NULL +}; + +static const struct attribute_group mc_attr_group = { + .attrs = mc_default_attrs, + .name = "microcode", +}; + +static void microcode_fini_cpu(int cpu) +{ + if (microcode_ops->microcode_fini_cpu) + microcode_ops->microcode_fini_cpu(cpu); +} + +/** + * microcode_bsp_resume - Update boot CPU microcode during resume. + */ +void microcode_bsp_resume(void) +{ + int cpu = smp_processor_id(); + struct ucode_cpu_info *uci = ucode_cpu_info + cpu; + + if (uci->mc) + microcode_ops->apply_microcode(cpu); + else + reload_early_microcode(cpu); +} + +static void microcode_bsp_syscore_resume(void *data) +{ + microcode_bsp_resume(); +} + +static const struct syscore_ops mc_syscore_ops = { + .resume = microcode_bsp_syscore_resume, +}; + +static struct syscore mc_syscore = { + .ops = &mc_syscore_ops, +}; + +static int mc_cpu_online(unsigned int cpu) +{ + struct ucode_cpu_info *uci = ucode_cpu_info + cpu; + struct device *dev = get_cpu_device(cpu); + + memset(uci, 0, sizeof(*uci)); + + microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig); + cpu_data(cpu).microcode = uci->cpu_sig.rev; + if (!cpu) + boot_cpu_data.microcode = uci->cpu_sig.rev; + + if (sysfs_create_group(&dev->kobj, &mc_attr_group)) + pr_err("Failed to create group for CPU%d\n", cpu); + return 0; +} + +static int mc_cpu_down_prep(unsigned int cpu) +{ + struct device *dev = get_cpu_device(cpu); + + microcode_fini_cpu(cpu); + sysfs_remove_group(&dev->kobj, &mc_attr_group); + return 0; +} + +static struct attribute *cpu_root_microcode_attrs[] = { +#ifdef CONFIG_MICROCODE_LATE_LOADING + &dev_attr_reload.attr, +#endif + NULL +}; + +static const struct attribute_group cpu_root_microcode_group = { + .name = "microcode", + .attrs = cpu_root_microcode_attrs, +}; + +static int __init microcode_init(void) +{ + struct device *dev_root; + struct cpuinfo_x86 *c = &boot_cpu_data; + int error; + + if (microcode_loader_disabled()) + return -EINVAL; + + if (c->x86_vendor == X86_VENDOR_INTEL) + microcode_ops = init_intel_microcode(); + else if (c->x86_vendor == X86_VENDOR_AMD) + microcode_ops = init_amd_microcode(); + else + pr_err("no support for this CPU vendor\n"); + + if (!microcode_ops) + return -ENODEV; + + pr_info_once("Current revision: 0x%08x\n", (early_data.new_rev ?: early_data.old_rev)); + + if (early_data.new_rev) + pr_info_once("Updated early from: 0x%08x\n", early_data.old_rev); + + microcode_fdev = faux_device_create("microcode", NULL, NULL); + if (!microcode_fdev) + return -ENODEV; + + dev_root = bus_get_dev_root(&cpu_subsys); + if (dev_root) { + error = sysfs_create_group(&dev_root->kobj, &cpu_root_microcode_group); + put_device(dev_root); + if (error) { + pr_err("Error creating microcode group!\n"); + goto out_pdev; + } + } + + register_syscore(&mc_syscore); + cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/microcode:online", + mc_cpu_online, mc_cpu_down_prep); + + return 0; + + out_pdev: + faux_device_destroy(microcode_fdev); + return error; + +} +late_initcall(microcode_init); |