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Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 1380 |
1 files changed, 1380 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c new file mode 100644 index 000000000..be4045628 --- /dev/null +++ b/arch/x86/kernel/cpu/intel.c @@ -0,0 +1,1380 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/pgtable.h> + +#include <linux/string.h> +#include <linux/bitops.h> +#include <linux/smp.h> +#include <linux/sched.h> +#include <linux/sched/clock.h> +#include <linux/semaphore.h> +#include <linux/thread_info.h> +#include <linux/init.h> +#include <linux/uaccess.h> +#include <linux/workqueue.h> +#include <linux/delay.h> +#include <linux/cpuhotplug.h> + +#include <asm/cpufeature.h> +#include <asm/msr.h> +#include <asm/bugs.h> +#include <asm/cpu.h> +#include <asm/intel-family.h> +#include <asm/microcode.h> +#include <asm/hwcap2.h> +#include <asm/elf.h> +#include <asm/cpu_device_id.h> +#include <asm/cmdline.h> +#include <asm/traps.h> +#include <asm/resctrl.h> +#include <asm/numa.h> +#include <asm/thermal.h> + +#ifdef CONFIG_X86_64 +#include <linux/topology.h> +#endif + +#include "cpu.h" + +#ifdef CONFIG_X86_LOCAL_APIC +#include <asm/mpspec.h> +#include <asm/apic.h> +#endif + +enum split_lock_detect_state { + sld_off = 0, + sld_warn, + sld_fatal, + sld_ratelimit, +}; + +/* + * Default to sld_off because most systems do not support split lock detection. + * sld_state_setup() will switch this to sld_warn on systems that support + * split lock/bus lock detect, unless there is a command line override. + */ +static enum split_lock_detect_state sld_state __ro_after_init = sld_off; +static u64 msr_test_ctrl_cache __ro_after_init; + +/* + * With a name like MSR_TEST_CTL it should go without saying, but don't touch + * MSR_TEST_CTL unless the CPU is one of the whitelisted models. Writing it + * on CPUs that do not support SLD can cause fireworks, even when writing '0'. + */ +static bool cpu_model_supports_sld __ro_after_init; + +/* + * Processors which have self-snooping capability can handle conflicting + * memory type across CPUs by snooping its own cache. However, there exists + * CPU models in which having conflicting memory types still leads to + * unpredictable behavior, machine check errors, or hangs. Clear this + * feature to prevent its use on machines with known erratas. + */ +static void check_memory_type_self_snoop_errata(struct cpuinfo_x86 *c) +{ + switch (c->x86_model) { + case INTEL_FAM6_CORE_YONAH: + case INTEL_FAM6_CORE2_MEROM: + case INTEL_FAM6_CORE2_MEROM_L: + case INTEL_FAM6_CORE2_PENRYN: + case INTEL_FAM6_CORE2_DUNNINGTON: + case INTEL_FAM6_NEHALEM: + case INTEL_FAM6_NEHALEM_G: + case INTEL_FAM6_NEHALEM_EP: + case INTEL_FAM6_NEHALEM_EX: + case INTEL_FAM6_WESTMERE: + case INTEL_FAM6_WESTMERE_EP: + case INTEL_FAM6_SANDYBRIDGE: + setup_clear_cpu_cap(X86_FEATURE_SELFSNOOP); + } +} + +static bool ring3mwait_disabled __read_mostly; + +static int __init ring3mwait_disable(char *__unused) +{ + ring3mwait_disabled = true; + return 1; +} +__setup("ring3mwait=disable", ring3mwait_disable); + +static void probe_xeon_phi_r3mwait(struct cpuinfo_x86 *c) +{ + /* + * Ring 3 MONITOR/MWAIT feature cannot be detected without + * cpu model and family comparison. + */ + if (c->x86 != 6) + return; + switch (c->x86_model) { + case INTEL_FAM6_XEON_PHI_KNL: + case INTEL_FAM6_XEON_PHI_KNM: + break; + default: + return; + } + + if (ring3mwait_disabled) + return; + + set_cpu_cap(c, X86_FEATURE_RING3MWAIT); + this_cpu_or(msr_misc_features_shadow, + 1UL << MSR_MISC_FEATURES_ENABLES_RING3MWAIT_BIT); + + if (c == &boot_cpu_data) + ELF_HWCAP2 |= HWCAP2_RING3MWAIT; +} + +/* + * Early microcode releases for the Spectre v2 mitigation were broken. + * Information taken from; + * - https://newsroom.intel.com/wp-content/uploads/sites/11/2018/03/microcode-update-guidance.pdf + * - https://kb.vmware.com/s/article/52345 + * - Microcode revisions observed in the wild + * - Release note from 20180108 microcode release + */ +struct sku_microcode { + u8 model; + u8 stepping; + u32 microcode; +}; +static const struct sku_microcode spectre_bad_microcodes[] = { + { INTEL_FAM6_KABYLAKE, 0x0B, 0x80 }, + { INTEL_FAM6_KABYLAKE, 0x0A, 0x80 }, + { INTEL_FAM6_KABYLAKE, 0x09, 0x80 }, + { INTEL_FAM6_KABYLAKE_L, 0x0A, 0x80 }, + { INTEL_FAM6_KABYLAKE_L, 0x09, 0x80 }, + { INTEL_FAM6_SKYLAKE_X, 0x03, 0x0100013e }, + { INTEL_FAM6_SKYLAKE_X, 0x04, 0x0200003c }, + { INTEL_FAM6_BROADWELL, 0x04, 0x28 }, + { INTEL_FAM6_BROADWELL_G, 0x01, 0x1b }, + { INTEL_FAM6_BROADWELL_D, 0x02, 0x14 }, + { INTEL_FAM6_BROADWELL_D, 0x03, 0x07000011 }, + { INTEL_FAM6_BROADWELL_X, 0x01, 0x0b000025 }, + { INTEL_FAM6_HASWELL_L, 0x01, 0x21 }, + { INTEL_FAM6_HASWELL_G, 0x01, 0x18 }, + { INTEL_FAM6_HASWELL, 0x03, 0x23 }, + { INTEL_FAM6_HASWELL_X, 0x02, 0x3b }, + { INTEL_FAM6_HASWELL_X, 0x04, 0x10 }, + { INTEL_FAM6_IVYBRIDGE_X, 0x04, 0x42a }, + /* Observed in the wild */ + { INTEL_FAM6_SANDYBRIDGE_X, 0x06, 0x61b }, + { INTEL_FAM6_SANDYBRIDGE_X, 0x07, 0x712 }, +}; + +static bool bad_spectre_microcode(struct cpuinfo_x86 *c) +{ + int i; + + /* + * We know that the hypervisor lie to us on the microcode version so + * we may as well hope that it is running the correct version. + */ + if (cpu_has(c, X86_FEATURE_HYPERVISOR)) + return false; + + if (c->x86 != 6) + return false; + + for (i = 0; i < ARRAY_SIZE(spectre_bad_microcodes); i++) { + if (c->x86_model == spectre_bad_microcodes[i].model && + c->x86_stepping == spectre_bad_microcodes[i].stepping) + return (c->microcode <= spectre_bad_microcodes[i].microcode); + } + return false; +} + +static void early_init_intel(struct cpuinfo_x86 *c) +{ + u64 misc_enable; + + /* Unmask CPUID levels if masked: */ + if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) { + if (msr_clear_bit(MSR_IA32_MISC_ENABLE, + MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0) { + c->cpuid_level = cpuid_eax(0); + get_cpu_cap(c); + } + } + + if ((c->x86 == 0xf && c->x86_model >= 0x03) || + (c->x86 == 0x6 && c->x86_model >= 0x0e)) + set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); + + if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64)) + c->microcode = intel_get_microcode_revision(); + + /* Now if any of them are set, check the blacklist and clear the lot */ + if ((cpu_has(c, X86_FEATURE_SPEC_CTRL) || + cpu_has(c, X86_FEATURE_INTEL_STIBP) || + cpu_has(c, X86_FEATURE_IBRS) || cpu_has(c, X86_FEATURE_IBPB) || + cpu_has(c, X86_FEATURE_STIBP)) && bad_spectre_microcode(c)) { + pr_warn("Intel Spectre v2 broken microcode detected; disabling Speculation Control\n"); + setup_clear_cpu_cap(X86_FEATURE_IBRS); + setup_clear_cpu_cap(X86_FEATURE_IBPB); + setup_clear_cpu_cap(X86_FEATURE_STIBP); + setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL); + setup_clear_cpu_cap(X86_FEATURE_MSR_SPEC_CTRL); + setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP); + setup_clear_cpu_cap(X86_FEATURE_SSBD); + setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL_SSBD); + } + + /* + * Atom erratum AAE44/AAF40/AAG38/AAH41: + * + * A race condition between speculative fetches and invalidating + * a large page. This is worked around in microcode, but we + * need the microcode to have already been loaded... so if it is + * not, recommend a BIOS update and disable large pages. + */ + if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_stepping <= 2 && + c->microcode < 0x20e) { + pr_warn("Atom PSE erratum detected, BIOS microcode update recommended\n"); + clear_cpu_cap(c, X86_FEATURE_PSE); + } + +#ifdef CONFIG_X86_64 + set_cpu_cap(c, X86_FEATURE_SYSENTER32); +#else + /* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */ + if (c->x86 == 15 && c->x86_cache_alignment == 64) + c->x86_cache_alignment = 128; +#endif + + /* CPUID workaround for 0F33/0F34 CPU */ + if (c->x86 == 0xF && c->x86_model == 0x3 + && (c->x86_stepping == 0x3 || c->x86_stepping == 0x4)) + c->x86_phys_bits = 36; + + /* + * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate + * with P/T states and does not stop in deep C-states. + * + * It is also reliable across cores and sockets. (but not across + * cabinets - we turn it off in that case explicitly.) + */ + if (c->x86_power & (1 << 8)) { + set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); + set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC); + } + + /* Penwell and Cloverview have the TSC which doesn't sleep on S3 */ + if (c->x86 == 6) { + switch (c->x86_model) { + case INTEL_FAM6_ATOM_SALTWELL_MID: + case INTEL_FAM6_ATOM_SALTWELL_TABLET: + case INTEL_FAM6_ATOM_SILVERMONT_MID: + case INTEL_FAM6_ATOM_AIRMONT_NP: + set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC_S3); + break; + default: + break; + } + } + + /* + * There is a known erratum on Pentium III and Core Solo + * and Core Duo CPUs. + * " Page with PAT set to WC while associated MTRR is UC + * may consolidate to UC " + * Because of this erratum, it is better to stick with + * setting WC in MTRR rather than using PAT on these CPUs. + * + * Enable PAT WC only on P4, Core 2 or later CPUs. + */ + if (c->x86 == 6 && c->x86_model < 15) + clear_cpu_cap(c, X86_FEATURE_PAT); + + /* + * If fast string is not enabled in IA32_MISC_ENABLE for any reason, + * clear the fast string and enhanced fast string CPU capabilities. + */ + if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) { + rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable); + if (!(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) { + pr_info("Disabled fast string operations\n"); + setup_clear_cpu_cap(X86_FEATURE_REP_GOOD); + setup_clear_cpu_cap(X86_FEATURE_ERMS); + } + } + + /* + * Intel Quark Core DevMan_001.pdf section 6.4.11 + * "The operating system also is required to invalidate (i.e., flush) + * the TLB when any changes are made to any of the page table entries. + * The operating system must reload CR3 to cause the TLB to be flushed" + * + * As a result, boot_cpu_has(X86_FEATURE_PGE) in arch/x86/include/asm/tlbflush.h + * should be false so that __flush_tlb_all() causes CR3 instead of CR4.PGE + * to be modified. + */ + if (c->x86 == 5 && c->x86_model == 9) { + pr_info("Disabling PGE capability bit\n"); + setup_clear_cpu_cap(X86_FEATURE_PGE); + } + + if (c->cpuid_level >= 0x00000001) { + u32 eax, ebx, ecx, edx; + + cpuid(0x00000001, &eax, &ebx, &ecx, &edx); + /* + * If HTT (EDX[28]) is set EBX[16:23] contain the number of + * apicids which are reserved per package. Store the resulting + * shift value for the package management code. + */ + if (edx & (1U << 28)) + c->x86_coreid_bits = get_count_order((ebx >> 16) & 0xff); + } + + check_memory_type_self_snoop_errata(c); + + /* + * Get the number of SMT siblings early from the extended topology + * leaf, if available. Otherwise try the legacy SMT detection. + */ + if (detect_extended_topology_early(c) < 0) + detect_ht_early(c); +} + +static void bsp_init_intel(struct cpuinfo_x86 *c) +{ + resctrl_cpu_detect(c); +} + +#ifdef CONFIG_X86_32 +/* + * Early probe support logic for ppro memory erratum #50 + * + * This is called before we do cpu ident work + */ + +int ppro_with_ram_bug(void) +{ + /* Uses data from early_cpu_detect now */ + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && + boot_cpu_data.x86 == 6 && + boot_cpu_data.x86_model == 1 && + boot_cpu_data.x86_stepping < 8) { + pr_info("Pentium Pro with Errata#50 detected. Taking evasive action.\n"); + return 1; + } + return 0; +} + +static void intel_smp_check(struct cpuinfo_x86 *c) +{ + /* calling is from identify_secondary_cpu() ? */ + if (!c->cpu_index) + return; + + /* + * Mask B, Pentium, but not Pentium MMX + */ + if (c->x86 == 5 && + c->x86_stepping >= 1 && c->x86_stepping <= 4 && + c->x86_model <= 3) { + /* + * Remember we have B step Pentia with bugs + */ + WARN_ONCE(1, "WARNING: SMP operation may be unreliable" + "with B stepping processors.\n"); + } +} + +static int forcepae; +static int __init forcepae_setup(char *__unused) +{ + forcepae = 1; + return 1; +} +__setup("forcepae", forcepae_setup); + +static void intel_workarounds(struct cpuinfo_x86 *c) +{ +#ifdef CONFIG_X86_F00F_BUG + /* + * All models of Pentium and Pentium with MMX technology CPUs + * have the F0 0F bug, which lets nonprivileged users lock up the + * system. Announce that the fault handler will be checking for it. + * The Quark is also family 5, but does not have the same bug. + */ + clear_cpu_bug(c, X86_BUG_F00F); + if (c->x86 == 5 && c->x86_model < 9) { + static int f00f_workaround_enabled; + + set_cpu_bug(c, X86_BUG_F00F); + if (!f00f_workaround_enabled) { + pr_notice("Intel Pentium with F0 0F bug - workaround enabled.\n"); + f00f_workaround_enabled = 1; + } + } +#endif + + /* + * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until + * model 3 mask 3 + */ + if ((c->x86<<8 | c->x86_model<<4 | c->x86_stepping) < 0x633) + clear_cpu_cap(c, X86_FEATURE_SEP); + + /* + * PAE CPUID issue: many Pentium M report no PAE but may have a + * functionally usable PAE implementation. + * Forcefully enable PAE if kernel parameter "forcepae" is present. + */ + if (forcepae) { + pr_warn("PAE forced!\n"); + set_cpu_cap(c, X86_FEATURE_PAE); + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE); + } + + /* + * P4 Xeon erratum 037 workaround. + * Hardware prefetcher may cause stale data to be loaded into the cache. + */ + if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_stepping == 1)) { + if (msr_set_bit(MSR_IA32_MISC_ENABLE, + MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE_BIT) > 0) { + pr_info("CPU: C0 stepping P4 Xeon detected.\n"); + pr_info("CPU: Disabling hardware prefetching (Erratum 037)\n"); + } + } + + /* + * See if we have a good local APIC by checking for buggy Pentia, + * i.e. all B steppings and the C2 stepping of P54C when using their + * integrated APIC (see 11AP erratum in "Pentium Processor + * Specification Update"). + */ + if (boot_cpu_has(X86_FEATURE_APIC) && (c->x86<<8 | c->x86_model<<4) == 0x520 && + (c->x86_stepping < 0x6 || c->x86_stepping == 0xb)) + set_cpu_bug(c, X86_BUG_11AP); + + +#ifdef CONFIG_X86_INTEL_USERCOPY + /* + * Set up the preferred alignment for movsl bulk memory moves + */ + switch (c->x86) { + case 4: /* 486: untested */ + break; + case 5: /* Old Pentia: untested */ + break; + case 6: /* PII/PIII only like movsl with 8-byte alignment */ + movsl_mask.mask = 7; + break; + case 15: /* P4 is OK down to 8-byte alignment */ + movsl_mask.mask = 7; + break; + } +#endif + + intel_smp_check(c); +} +#else +static void intel_workarounds(struct cpuinfo_x86 *c) +{ +} +#endif + +static void srat_detect_node(struct cpuinfo_x86 *c) +{ +#ifdef CONFIG_NUMA + unsigned node; + int cpu = smp_processor_id(); + + /* Don't do the funky fallback heuristics the AMD version employs + for now. */ + node = numa_cpu_node(cpu); + if (node == NUMA_NO_NODE || !node_online(node)) { + /* reuse the value from init_cpu_to_node() */ + node = cpu_to_node(cpu); + } + numa_set_node(cpu, node); +#endif +} + +#define MSR_IA32_TME_ACTIVATE 0x982 + +/* Helpers to access TME_ACTIVATE MSR */ +#define TME_ACTIVATE_LOCKED(x) (x & 0x1) +#define TME_ACTIVATE_ENABLED(x) (x & 0x2) + +#define TME_ACTIVATE_POLICY(x) ((x >> 4) & 0xf) /* Bits 7:4 */ +#define TME_ACTIVATE_POLICY_AES_XTS_128 0 + +#define TME_ACTIVATE_KEYID_BITS(x) ((x >> 32) & 0xf) /* Bits 35:32 */ + +#define TME_ACTIVATE_CRYPTO_ALGS(x) ((x >> 48) & 0xffff) /* Bits 63:48 */ +#define TME_ACTIVATE_CRYPTO_AES_XTS_128 1 + +/* Values for mktme_status (SW only construct) */ +#define MKTME_ENABLED 0 +#define MKTME_DISABLED 1 +#define MKTME_UNINITIALIZED 2 +static int mktme_status = MKTME_UNINITIALIZED; + +static void detect_tme(struct cpuinfo_x86 *c) +{ + u64 tme_activate, tme_policy, tme_crypto_algs; + int keyid_bits = 0, nr_keyids = 0; + static u64 tme_activate_cpu0 = 0; + + rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate); + + if (mktme_status != MKTME_UNINITIALIZED) { + if (tme_activate != tme_activate_cpu0) { + /* Broken BIOS? */ + pr_err_once("x86/tme: configuration is inconsistent between CPUs\n"); + pr_err_once("x86/tme: MKTME is not usable\n"); + mktme_status = MKTME_DISABLED; + + /* Proceed. We may need to exclude bits from x86_phys_bits. */ + } + } else { + tme_activate_cpu0 = tme_activate; + } + + if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) { + pr_info_once("x86/tme: not enabled by BIOS\n"); + mktme_status = MKTME_DISABLED; + return; + } + + if (mktme_status != MKTME_UNINITIALIZED) + goto detect_keyid_bits; + + pr_info("x86/tme: enabled by BIOS\n"); + + tme_policy = TME_ACTIVATE_POLICY(tme_activate); + if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128) + pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy); + + tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate); + if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) { + pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n", + tme_crypto_algs); + mktme_status = MKTME_DISABLED; + } +detect_keyid_bits: + keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate); + nr_keyids = (1UL << keyid_bits) - 1; + if (nr_keyids) { + pr_info_once("x86/mktme: enabled by BIOS\n"); + pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids); + } else { + pr_info_once("x86/mktme: disabled by BIOS\n"); + } + + if (mktme_status == MKTME_UNINITIALIZED) { + /* MKTME is usable */ + mktme_status = MKTME_ENABLED; + } + + /* + * KeyID bits effectively lower the number of physical address + * bits. Update cpuinfo_x86::x86_phys_bits accordingly. + */ + c->x86_phys_bits -= keyid_bits; +} + +static void init_cpuid_fault(struct cpuinfo_x86 *c) +{ + u64 msr; + + if (!rdmsrl_safe(MSR_PLATFORM_INFO, &msr)) { + if (msr & MSR_PLATFORM_INFO_CPUID_FAULT) + set_cpu_cap(c, X86_FEATURE_CPUID_FAULT); + } +} + +static void init_intel_misc_features(struct cpuinfo_x86 *c) +{ + u64 msr; + + if (rdmsrl_safe(MSR_MISC_FEATURES_ENABLES, &msr)) + return; + + /* Clear all MISC features */ + this_cpu_write(msr_misc_features_shadow, 0); + + /* Check features and update capabilities and shadow control bits */ + init_cpuid_fault(c); + probe_xeon_phi_r3mwait(c); + + msr = this_cpu_read(msr_misc_features_shadow); + wrmsrl(MSR_MISC_FEATURES_ENABLES, msr); +} + +static void split_lock_init(void); +static void bus_lock_init(void); + +static void init_intel(struct cpuinfo_x86 *c) +{ + early_init_intel(c); + + intel_workarounds(c); + + /* + * Detect the extended topology information if available. This + * will reinitialise the initial_apicid which will be used + * in init_intel_cacheinfo() + */ + detect_extended_topology(c); + + if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) { + /* + * let's use the legacy cpuid vector 0x1 and 0x4 for topology + * detection. + */ + detect_num_cpu_cores(c); +#ifdef CONFIG_X86_32 + detect_ht(c); +#endif + } + + init_intel_cacheinfo(c); + + if (c->cpuid_level > 9) { + unsigned eax = cpuid_eax(10); + /* Check for version and the number of counters */ + if ((eax & 0xff) && (((eax>>8) & 0xff) > 1)) + set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON); + } + + if (cpu_has(c, X86_FEATURE_XMM2)) + set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC); + + if (boot_cpu_has(X86_FEATURE_DS)) { + unsigned int l1, l2; + + rdmsr(MSR_IA32_MISC_ENABLE, l1, l2); + if (!(l1 & MSR_IA32_MISC_ENABLE_BTS_UNAVAIL)) + set_cpu_cap(c, X86_FEATURE_BTS); + if (!(l1 & MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL)) + set_cpu_cap(c, X86_FEATURE_PEBS); + } + + if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_CLFLUSH) && + (c->x86_model == 29 || c->x86_model == 46 || c->x86_model == 47)) + set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR); + + if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_MWAIT) && + ((c->x86_model == INTEL_FAM6_ATOM_GOLDMONT))) + set_cpu_bug(c, X86_BUG_MONITOR); + +#ifdef CONFIG_X86_64 + if (c->x86 == 15) + c->x86_cache_alignment = c->x86_clflush_size * 2; + if (c->x86 == 6) + set_cpu_cap(c, X86_FEATURE_REP_GOOD); +#else + /* + * Names for the Pentium II/Celeron processors + * detectable only by also checking the cache size. + * Dixon is NOT a Celeron. + */ + if (c->x86 == 6) { + unsigned int l2 = c->x86_cache_size; + char *p = NULL; + + switch (c->x86_model) { + case 5: + if (l2 == 0) + p = "Celeron (Covington)"; + else if (l2 == 256) + p = "Mobile Pentium II (Dixon)"; + break; + + case 6: + if (l2 == 128) + p = "Celeron (Mendocino)"; + else if (c->x86_stepping == 0 || c->x86_stepping == 5) + p = "Celeron-A"; + break; + + case 8: + if (l2 == 128) + p = "Celeron (Coppermine)"; + break; + } + + if (p) + strcpy(c->x86_model_id, p); + } + + if (c->x86 == 15) + set_cpu_cap(c, X86_FEATURE_P4); + if (c->x86 == 6) + set_cpu_cap(c, X86_FEATURE_P3); +#endif + + /* Work around errata */ + srat_detect_node(c); + + init_ia32_feat_ctl(c); + + if (cpu_has(c, X86_FEATURE_TME)) + detect_tme(c); + + init_intel_misc_features(c); + + split_lock_init(); + bus_lock_init(); + + intel_init_thermal(c); +} + +#ifdef CONFIG_X86_32 +static unsigned int intel_size_cache(struct cpuinfo_x86 *c, unsigned int size) +{ + /* + * Intel PIII Tualatin. This comes in two flavours. + * One has 256kb of cache, the other 512. We have no way + * to determine which, so we use a boottime override + * for the 512kb model, and assume 256 otherwise. + */ + if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0)) + size = 256; + + /* + * Intel Quark SoC X1000 contains a 4-way set associative + * 16K cache with a 16 byte cache line and 256 lines per tag + */ + if ((c->x86 == 5) && (c->x86_model == 9)) + size = 16; + return size; +} +#endif + +#define TLB_INST_4K 0x01 +#define TLB_INST_4M 0x02 +#define TLB_INST_2M_4M 0x03 + +#define TLB_INST_ALL 0x05 +#define TLB_INST_1G 0x06 + +#define TLB_DATA_4K 0x11 +#define TLB_DATA_4M 0x12 +#define TLB_DATA_2M_4M 0x13 +#define TLB_DATA_4K_4M 0x14 + +#define TLB_DATA_1G 0x16 + +#define TLB_DATA0_4K 0x21 +#define TLB_DATA0_4M 0x22 +#define TLB_DATA0_2M_4M 0x23 + +#define STLB_4K 0x41 +#define STLB_4K_2M 0x42 + +static const struct _tlb_table intel_tlb_table[] = { + { 0x01, TLB_INST_4K, 32, " TLB_INST 4 KByte pages, 4-way set associative" }, + { 0x02, TLB_INST_4M, 2, " TLB_INST 4 MByte pages, full associative" }, + { 0x03, TLB_DATA_4K, 64, " TLB_DATA 4 KByte pages, 4-way set associative" }, + { 0x04, TLB_DATA_4M, 8, " TLB_DATA 4 MByte pages, 4-way set associative" }, + { 0x05, TLB_DATA_4M, 32, " TLB_DATA 4 MByte pages, 4-way set associative" }, + { 0x0b, TLB_INST_4M, 4, " TLB_INST 4 MByte pages, 4-way set associative" }, + { 0x4f, TLB_INST_4K, 32, " TLB_INST 4 KByte pages" }, + { 0x50, TLB_INST_ALL, 64, " TLB_INST 4 KByte and 2-MByte or 4-MByte pages" }, + { 0x51, TLB_INST_ALL, 128, " TLB_INST 4 KByte and 2-MByte or 4-MByte pages" }, + { 0x52, TLB_INST_ALL, 256, " TLB_INST 4 KByte and 2-MByte or 4-MByte pages" }, + { 0x55, TLB_INST_2M_4M, 7, " TLB_INST 2-MByte or 4-MByte pages, fully associative" }, + { 0x56, TLB_DATA0_4M, 16, " TLB_DATA0 4 MByte pages, 4-way set associative" }, + { 0x57, TLB_DATA0_4K, 16, " TLB_DATA0 4 KByte pages, 4-way associative" }, + { 0x59, TLB_DATA0_4K, 16, " TLB_DATA0 4 KByte pages, fully associative" }, + { 0x5a, TLB_DATA0_2M_4M, 32, " TLB_DATA0 2-MByte or 4 MByte pages, 4-way set associative" }, + { 0x5b, TLB_DATA_4K_4M, 64, " TLB_DATA 4 KByte and 4 MByte pages" }, + { 0x5c, TLB_DATA_4K_4M, 128, " TLB_DATA 4 KByte and 4 MByte pages" }, + { 0x5d, TLB_DATA_4K_4M, 256, " TLB_DATA 4 KByte and 4 MByte pages" }, + { 0x61, TLB_INST_4K, 48, " TLB_INST 4 KByte pages, full associative" }, + { 0x63, TLB_DATA_1G, 4, " TLB_DATA 1 GByte pages, 4-way set associative" }, + { 0x6b, TLB_DATA_4K, 256, " TLB_DATA 4 KByte pages, 8-way associative" }, + { 0x6c, TLB_DATA_2M_4M, 128, " TLB_DATA 2 MByte or 4 MByte pages, 8-way associative" }, + { 0x6d, TLB_DATA_1G, 16, " TLB_DATA 1 GByte pages, fully associative" }, + { 0x76, TLB_INST_2M_4M, 8, " TLB_INST 2-MByte or 4-MByte pages, fully associative" }, + { 0xb0, TLB_INST_4K, 128, " TLB_INST 4 KByte pages, 4-way set associative" }, + { 0xb1, TLB_INST_2M_4M, 4, " TLB_INST 2M pages, 4-way, 8 entries or 4M pages, 4-way entries" }, + { 0xb2, TLB_INST_4K, 64, " TLB_INST 4KByte pages, 4-way set associative" }, + { 0xb3, TLB_DATA_4K, 128, " TLB_DATA 4 KByte pages, 4-way set associative" }, + { 0xb4, TLB_DATA_4K, 256, " TLB_DATA 4 KByte pages, 4-way associative" }, + { 0xb5, TLB_INST_4K, 64, " TLB_INST 4 KByte pages, 8-way set associative" }, + { 0xb6, TLB_INST_4K, 128, " TLB_INST 4 KByte pages, 8-way set associative" }, + { 0xba, TLB_DATA_4K, 64, " TLB_DATA 4 KByte pages, 4-way associative" }, + { 0xc0, TLB_DATA_4K_4M, 8, " TLB_DATA 4 KByte and 4 MByte pages, 4-way associative" }, + { 0xc1, STLB_4K_2M, 1024, " STLB 4 KByte and 2 MByte pages, 8-way associative" }, + { 0xc2, TLB_DATA_2M_4M, 16, " TLB_DATA 2 MByte/4MByte pages, 4-way associative" }, + { 0xca, STLB_4K, 512, " STLB 4 KByte pages, 4-way associative" }, + { 0x00, 0, 0 } +}; + +static void intel_tlb_lookup(const unsigned char desc) +{ + unsigned char k; + if (desc == 0) + return; + + /* look up this descriptor in the table */ + for (k = 0; intel_tlb_table[k].descriptor != desc && + intel_tlb_table[k].descriptor != 0; k++) + ; + + if (intel_tlb_table[k].tlb_type == 0) + return; + + switch (intel_tlb_table[k].tlb_type) { + case STLB_4K: + if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries) + tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries; + if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries) + tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries; + break; + case STLB_4K_2M: + if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries) + tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries; + if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries) + tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries; + if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries) + tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries; + if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries) + tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries; + if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries) + tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries; + if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries) + tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries; + break; + case TLB_INST_ALL: + if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries) + tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries; + if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries) + tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries; + if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries) + tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries; + break; + case TLB_INST_4K: + if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries) + tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries; + break; + case TLB_INST_4M: + if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries) + tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries; + break; + case TLB_INST_2M_4M: + if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries) + tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries; + if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries) + tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries; + break; + case TLB_DATA_4K: + case TLB_DATA0_4K: + if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries) + tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries; + break; + case TLB_DATA_4M: + case TLB_DATA0_4M: + if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries) + tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries; + break; + case TLB_DATA_2M_4M: + case TLB_DATA0_2M_4M: + if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries) + tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries; + if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries) + tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries; + break; + case TLB_DATA_4K_4M: + if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries) + tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries; + if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries) + tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries; + break; + case TLB_DATA_1G: + if (tlb_lld_1g[ENTRIES] < intel_tlb_table[k].entries) + tlb_lld_1g[ENTRIES] = intel_tlb_table[k].entries; + break; + } +} + +static void intel_detect_tlb(struct cpuinfo_x86 *c) +{ + int i, j, n; + unsigned int regs[4]; + unsigned char *desc = (unsigned char *)regs; + + if (c->cpuid_level < 2) + return; + + /* Number of times to iterate */ + n = cpuid_eax(2) & 0xFF; + + for (i = 0 ; i < n ; i++) { + cpuid(2, ®s[0], ®s[1], ®s[2], ®s[3]); + + /* If bit 31 is set, this is an unknown format */ + for (j = 0 ; j < 3 ; j++) + if (regs[j] & (1 << 31)) + regs[j] = 0; + + /* Byte 0 is level count, not a descriptor */ + for (j = 1 ; j < 16 ; j++) + intel_tlb_lookup(desc[j]); + } +} + +static const struct cpu_dev intel_cpu_dev = { + .c_vendor = "Intel", + .c_ident = { "GenuineIntel" }, +#ifdef CONFIG_X86_32 + .legacy_models = { + { .family = 4, .model_names = + { + [0] = "486 DX-25/33", + [1] = "486 DX-50", + [2] = "486 SX", + [3] = "486 DX/2", + [4] = "486 SL", + [5] = "486 SX/2", + [7] = "486 DX/2-WB", + [8] = "486 DX/4", + [9] = "486 DX/4-WB" + } + }, + { .family = 5, .model_names = + { + [0] = "Pentium 60/66 A-step", + [1] = "Pentium 60/66", + [2] = "Pentium 75 - 200", + [3] = "OverDrive PODP5V83", + [4] = "Pentium MMX", + [7] = "Mobile Pentium 75 - 200", + [8] = "Mobile Pentium MMX", + [9] = "Quark SoC X1000", + } + }, + { .family = 6, .model_names = + { + [0] = "Pentium Pro A-step", + [1] = "Pentium Pro", + [3] = "Pentium II (Klamath)", + [4] = "Pentium II (Deschutes)", + [5] = "Pentium II (Deschutes)", + [6] = "Mobile Pentium II", + [7] = "Pentium III (Katmai)", + [8] = "Pentium III (Coppermine)", + [10] = "Pentium III (Cascades)", + [11] = "Pentium III (Tualatin)", + } + }, + { .family = 15, .model_names = + { + [0] = "Pentium 4 (Unknown)", + [1] = "Pentium 4 (Willamette)", + [2] = "Pentium 4 (Northwood)", + [4] = "Pentium 4 (Foster)", + [5] = "Pentium 4 (Foster)", + } + }, + }, + .legacy_cache_size = intel_size_cache, +#endif + .c_detect_tlb = intel_detect_tlb, + .c_early_init = early_init_intel, + .c_bsp_init = bsp_init_intel, + .c_init = init_intel, + .c_x86_vendor = X86_VENDOR_INTEL, +}; + +cpu_dev_register(intel_cpu_dev); + +#undef pr_fmt +#define pr_fmt(fmt) "x86/split lock detection: " fmt + +static const struct { + const char *option; + enum split_lock_detect_state state; +} sld_options[] __initconst = { + { "off", sld_off }, + { "warn", sld_warn }, + { "fatal", sld_fatal }, + { "ratelimit:", sld_ratelimit }, +}; + +static struct ratelimit_state bld_ratelimit; + +static unsigned int sysctl_sld_mitigate = 1; +static DEFINE_SEMAPHORE(buslock_sem, 1); + +#ifdef CONFIG_PROC_SYSCTL +static struct ctl_table sld_sysctls[] = { + { + .procname = "split_lock_mitigate", + .data = &sysctl_sld_mitigate, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_douintvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + {} +}; + +static int __init sld_mitigate_sysctl_init(void) +{ + register_sysctl_init("kernel", sld_sysctls); + return 0; +} + +late_initcall(sld_mitigate_sysctl_init); +#endif + +static inline bool match_option(const char *arg, int arglen, const char *opt) +{ + int len = strlen(opt), ratelimit; + + if (strncmp(arg, opt, len)) + return false; + + /* + * Min ratelimit is 1 bus lock/sec. + * Max ratelimit is 1000 bus locks/sec. + */ + if (sscanf(arg, "ratelimit:%d", &ratelimit) == 1 && + ratelimit > 0 && ratelimit <= 1000) { + ratelimit_state_init(&bld_ratelimit, HZ, ratelimit); + ratelimit_set_flags(&bld_ratelimit, RATELIMIT_MSG_ON_RELEASE); + return true; + } + + return len == arglen; +} + +static bool split_lock_verify_msr(bool on) +{ + u64 ctrl, tmp; + + if (rdmsrl_safe(MSR_TEST_CTRL, &ctrl)) + return false; + if (on) + ctrl |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT; + else + ctrl &= ~MSR_TEST_CTRL_SPLIT_LOCK_DETECT; + if (wrmsrl_safe(MSR_TEST_CTRL, ctrl)) + return false; + rdmsrl(MSR_TEST_CTRL, tmp); + return ctrl == tmp; +} + +static void __init sld_state_setup(void) +{ + enum split_lock_detect_state state = sld_warn; + char arg[20]; + int i, ret; + + if (!boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) && + !boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) + return; + + ret = cmdline_find_option(boot_command_line, "split_lock_detect", + arg, sizeof(arg)); + if (ret >= 0) { + for (i = 0; i < ARRAY_SIZE(sld_options); i++) { + if (match_option(arg, ret, sld_options[i].option)) { + state = sld_options[i].state; + break; + } + } + } + sld_state = state; +} + +static void __init __split_lock_setup(void) +{ + if (!split_lock_verify_msr(false)) { + pr_info("MSR access failed: Disabled\n"); + return; + } + + rdmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache); + + if (!split_lock_verify_msr(true)) { + pr_info("MSR access failed: Disabled\n"); + return; + } + + /* Restore the MSR to its cached value. */ + wrmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache); + + setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT); +} + +/* + * MSR_TEST_CTRL is per core, but we treat it like a per CPU MSR. Locking + * is not implemented as one thread could undo the setting of the other + * thread immediately after dropping the lock anyway. + */ +static void sld_update_msr(bool on) +{ + u64 test_ctrl_val = msr_test_ctrl_cache; + + if (on) + test_ctrl_val |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT; + + wrmsrl(MSR_TEST_CTRL, test_ctrl_val); +} + +static void split_lock_init(void) +{ + /* + * #DB for bus lock handles ratelimit and #AC for split lock is + * disabled. + */ + if (sld_state == sld_ratelimit) { + split_lock_verify_msr(false); + return; + } + + if (cpu_model_supports_sld) + split_lock_verify_msr(sld_state != sld_off); +} + +static void __split_lock_reenable_unlock(struct work_struct *work) +{ + sld_update_msr(true); + up(&buslock_sem); +} + +static DECLARE_DELAYED_WORK(sl_reenable_unlock, __split_lock_reenable_unlock); + +static void __split_lock_reenable(struct work_struct *work) +{ + sld_update_msr(true); +} +static DECLARE_DELAYED_WORK(sl_reenable, __split_lock_reenable); + +/* + * If a CPU goes offline with pending delayed work to re-enable split lock + * detection then the delayed work will be executed on some other CPU. That + * handles releasing the buslock_sem, but because it executes on a + * different CPU probably won't re-enable split lock detection. This is a + * problem on HT systems since the sibling CPU on the same core may then be + * left running with split lock detection disabled. + * + * Unconditionally re-enable detection here. + */ +static int splitlock_cpu_offline(unsigned int cpu) +{ + sld_update_msr(true); + + return 0; +} + +static void split_lock_warn(unsigned long ip) +{ + struct delayed_work *work; + int cpu; + + if (!current->reported_split_lock) + pr_warn_ratelimited("#AC: %s/%d took a split_lock trap at address: 0x%lx\n", + current->comm, current->pid, ip); + current->reported_split_lock = 1; + + if (sysctl_sld_mitigate) { + /* + * misery factor #1: + * sleep 10ms before trying to execute split lock. + */ + if (msleep_interruptible(10) > 0) + return; + /* + * Misery factor #2: + * only allow one buslocked disabled core at a time. + */ + if (down_interruptible(&buslock_sem) == -EINTR) + return; + work = &sl_reenable_unlock; + } else { + work = &sl_reenable; + } + + cpu = get_cpu(); + schedule_delayed_work_on(cpu, work, 2); + + /* Disable split lock detection on this CPU to make progress */ + sld_update_msr(false); + put_cpu(); +} + +bool handle_guest_split_lock(unsigned long ip) +{ + if (sld_state == sld_warn) { + split_lock_warn(ip); + return true; + } + + pr_warn_once("#AC: %s/%d %s split_lock trap at address: 0x%lx\n", + current->comm, current->pid, + sld_state == sld_fatal ? "fatal" : "bogus", ip); + + current->thread.error_code = 0; + current->thread.trap_nr = X86_TRAP_AC; + force_sig_fault(SIGBUS, BUS_ADRALN, NULL); + return false; +} +EXPORT_SYMBOL_GPL(handle_guest_split_lock); + +static void bus_lock_init(void) +{ + u64 val; + + if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) + return; + + rdmsrl(MSR_IA32_DEBUGCTLMSR, val); + + if ((boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) && + (sld_state == sld_warn || sld_state == sld_fatal)) || + sld_state == sld_off) { + /* + * Warn and fatal are handled by #AC for split lock if #AC for + * split lock is supported. + */ + val &= ~DEBUGCTLMSR_BUS_LOCK_DETECT; + } else { + val |= DEBUGCTLMSR_BUS_LOCK_DETECT; + } + + wrmsrl(MSR_IA32_DEBUGCTLMSR, val); +} + +bool handle_user_split_lock(struct pt_regs *regs, long error_code) +{ + if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal) + return false; + split_lock_warn(regs->ip); + return true; +} + +void handle_bus_lock(struct pt_regs *regs) +{ + switch (sld_state) { + case sld_off: + break; + case sld_ratelimit: + /* Enforce no more than bld_ratelimit bus locks/sec. */ + while (!__ratelimit(&bld_ratelimit)) + msleep(20); + /* Warn on the bus lock. */ + fallthrough; + case sld_warn: + pr_warn_ratelimited("#DB: %s/%d took a bus_lock trap at address: 0x%lx\n", + current->comm, current->pid, regs->ip); + break; + case sld_fatal: + force_sig_fault(SIGBUS, BUS_ADRALN, NULL); + break; + } +} + +/* + * CPU models that are known to have the per-core split-lock detection + * feature even though they do not enumerate IA32_CORE_CAPABILITIES. + */ +static const struct x86_cpu_id split_lock_cpu_ids[] __initconst = { + X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X, 0), + X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_L, 0), + X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D, 0), + {} +}; + +static void __init split_lock_setup(struct cpuinfo_x86 *c) +{ + const struct x86_cpu_id *m; + u64 ia32_core_caps; + + if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) + return; + + /* Check for CPUs that have support but do not enumerate it: */ + m = x86_match_cpu(split_lock_cpu_ids); + if (m) + goto supported; + + if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES)) + return; + + /* + * Not all bits in MSR_IA32_CORE_CAPS are architectural, but + * MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT is. All CPUs that set + * it have split lock detection. + */ + rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps); + if (ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT) + goto supported; + + /* CPU is not in the model list and does not have the MSR bit: */ + return; + +supported: + cpu_model_supports_sld = true; + __split_lock_setup(); +} + +static void sld_state_show(void) +{ + if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT) && + !boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) + return; + + switch (sld_state) { + case sld_off: + pr_info("disabled\n"); + break; + case sld_warn: + if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) { + pr_info("#AC: crashing the kernel on kernel split_locks and warning on user-space split_locks\n"); + if (cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, + "x86/splitlock", NULL, splitlock_cpu_offline) < 0) + pr_warn("No splitlock CPU offline handler\n"); + } else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) { + pr_info("#DB: warning on user-space bus_locks\n"); + } + break; + case sld_fatal: + if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) { + pr_info("#AC: crashing the kernel on kernel split_locks and sending SIGBUS on user-space split_locks\n"); + } else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) { + pr_info("#DB: sending SIGBUS on user-space bus_locks%s\n", + boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) ? + " from non-WB" : ""); + } + break; + case sld_ratelimit: + if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) + pr_info("#DB: setting system wide bus lock rate limit to %u/sec\n", bld_ratelimit.burst); + break; + } +} + +void __init sld_setup(struct cpuinfo_x86 *c) +{ + split_lock_setup(c); + sld_state_setup(); + sld_state_show(); +} + +#define X86_HYBRID_CPU_TYPE_ID_SHIFT 24 + +/** + * get_this_hybrid_cpu_type() - Get the type of this hybrid CPU + * + * Returns the CPU type [31:24] (i.e., Atom or Core) of a CPU in + * a hybrid processor. If the processor is not hybrid, returns 0. + */ +u8 get_this_hybrid_cpu_type(void) +{ + if (!cpu_feature_enabled(X86_FEATURE_HYBRID_CPU)) + return 0; + + return cpuid_eax(0x0000001a) >> X86_HYBRID_CPU_TYPE_ID_SHIFT; +} |