diff options
Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 966 |
1 files changed, 204 insertions, 762 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index be30d7fa2e66..076eaa41b8c8 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -1,68 +1,33 @@ // 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 <linux/kernel.h> +#include <linux/minmax.h> +#include <linux/smp.h> +#include <linux/string.h> +#include <linux/types.h> + +#ifdef CONFIG_X86_64 +#include <linux/topology.h> +#endif -#include <asm/cpufeature.h> -#include <asm/msr.h> #include <asm/bugs.h> +#include <asm/cpu_device_id.h> +#include <asm/cpufeature.h> #include <asm/cpu.h> +#include <asm/cpuid/api.h> +#include <asm/hwcap2.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/msr.h> #include <asm/numa.h> +#include <asm/resctrl.h> #include <asm/thermal.h> - -#ifdef CONFIG_X86_64 -#include <linux/topology.h> -#endif +#include <asm/uaccess.h> #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 @@ -72,19 +37,19 @@ static bool cpu_model_supports_sld __ro_after_init; */ 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: + switch (c->x86_vfm) { + case INTEL_CORE_YONAH: + case INTEL_CORE2_MEROM: + case INTEL_CORE2_MEROM_L: + case INTEL_CORE2_PENRYN: + case INTEL_CORE2_DUNNINGTON: + case INTEL_NEHALEM: + case INTEL_NEHALEM_G: + case INTEL_NEHALEM_EP: + case INTEL_NEHALEM_EX: + case INTEL_WESTMERE: + case INTEL_WESTMERE_EP: + case INTEL_SANDYBRIDGE: setup_clear_cpu_cap(X86_FEATURE_SELFSNOOP); } } @@ -106,9 +71,9 @@ static void probe_xeon_phi_r3mwait(struct cpuinfo_x86 *c) */ if (c->x86 != 6) return; - switch (c->x86_model) { - case INTEL_FAM6_XEON_PHI_KNL: - case INTEL_FAM6_XEON_PHI_KNM: + switch (c->x86_vfm) { + case INTEL_XEON_PHI_KNL: + case INTEL_XEON_PHI_KNM: break; default: return; @@ -134,32 +99,32 @@ static void probe_xeon_phi_r3mwait(struct cpuinfo_x86 *c) * - Release note from 20180108 microcode release */ struct sku_microcode { - u8 model; + u32 vfm; 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 }, + { INTEL_KABYLAKE, 0x0B, 0x80 }, + { INTEL_KABYLAKE, 0x0A, 0x80 }, + { INTEL_KABYLAKE, 0x09, 0x80 }, + { INTEL_KABYLAKE_L, 0x0A, 0x80 }, + { INTEL_KABYLAKE_L, 0x09, 0x80 }, + { INTEL_SKYLAKE_X, 0x03, 0x0100013e }, + { INTEL_SKYLAKE_X, 0x04, 0x0200003c }, + { INTEL_BROADWELL, 0x04, 0x28 }, + { INTEL_BROADWELL_G, 0x01, 0x1b }, + { INTEL_BROADWELL_D, 0x02, 0x14 }, + { INTEL_BROADWELL_D, 0x03, 0x07000011 }, + { INTEL_BROADWELL_X, 0x01, 0x0b000025 }, + { INTEL_HASWELL_L, 0x01, 0x21 }, + { INTEL_HASWELL_G, 0x01, 0x18 }, + { INTEL_HASWELL, 0x03, 0x23 }, + { INTEL_HASWELL_X, 0x02, 0x3b }, + { INTEL_HASWELL_X, 0x04, 0x10 }, + { INTEL_IVYBRIDGE_X, 0x04, 0x42a }, /* Observed in the wild */ - { INTEL_FAM6_SANDYBRIDGE_X, 0x06, 0x61b }, - { INTEL_FAM6_SANDYBRIDGE_X, 0x07, 0x712 }, + { INTEL_SANDYBRIDGE_X, 0x06, 0x61b }, + { INTEL_SANDYBRIDGE_X, 0x07, 0x712 }, }; static bool bad_spectre_microcode(struct cpuinfo_x86 *c) @@ -173,11 +138,8 @@ static bool bad_spectre_microcode(struct cpuinfo_x86 *c) 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 && + if (c->x86_vfm == spectre_bad_microcodes[i].vfm && c->x86_stepping == spectre_bad_microcodes[i].stepping) return (c->microcode <= spectre_bad_microcodes[i].microcode); } @@ -190,101 +152,57 @@ static bool bad_spectre_microcode(struct cpuinfo_x86 *c) #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_early(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); + u64 tme_activate; + int keyid_bits; - 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; - } + rdmsrq(MSR_IA32_TME_ACTIVATE, 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; + clear_cpu_cap(c, X86_FEATURE_TME); return; } + pr_info_once("x86/tme: enabled by BIOS\n"); + keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate); + if (!keyid_bits) + 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); + /* + * KeyID bits are set by BIOS and can be present regardless + * of whether the kernel is using them. They effectively lower + * the number of physical address bits. + * + * Update cpuinfo_x86::x86_phys_bits accordingly. + */ + c->x86_phys_bits -= keyid_bits; + pr_info_once("x86/mktme: BIOS enabled: x86_phys_bits reduced by %d\n", + keyid_bits); +} - 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"); - } +void intel_unlock_cpuid_leafs(struct cpuinfo_x86 *c) +{ + if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) + return; - if (mktme_status == MKTME_UNINITIALIZED) { - /* MKTME is usable */ - mktme_status = MKTME_ENABLED; - } + if (c->x86_vfm < INTEL_PENTIUM_M_DOTHAN) + return; /* - * KeyID bits effectively lower the number of physical address - * bits. Update cpuinfo_x86::x86_phys_bits accordingly. + * The BIOS can have limited CPUID to leaf 2, which breaks feature + * enumeration. Unlock it and update the maximum leaf info. */ - c->x86_phys_bits -= keyid_bits; + if (msr_clear_bit(MSR_IA32_MISC_ENABLE, MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0) + c->cpuid_level = cpuid_eax(0); } 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(); @@ -312,7 +230,7 @@ static void early_init_intel(struct cpuinfo_x86 *c) * 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 && + if (c->x86_vfm == INTEL_ATOM_BONNELL && 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); @@ -327,8 +245,8 @@ static void early_init_intel(struct cpuinfo_x86 *c) #endif /* CPUID workaround for 0F33/0F34 CPU */ - if (c->x86 == 0xF && c->x86_model == 0x3 - && (c->x86_stepping == 0x3 || c->x86_stepping == 0x4)) + if (c->x86_vfm == INTEL_P4_PRESCOTT && + (c->x86_stepping == 0x3 || c->x86_stepping == 0x4)) c->x86_phys_bits = 36; /* @@ -337,46 +255,57 @@ static void early_init_intel(struct cpuinfo_x86 *c) * * It is also reliable across cores and sockets. (but not across * cabinets - we turn it off in that case explicitly.) + * + * Use a model-specific check for some older CPUs that have invariant + * TSC but may not report it architecturally via 8000_0007. */ if (c->x86_power & (1 << 8)) { set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC); + } else if ((c->x86_vfm >= INTEL_P4_PRESCOTT && c->x86_vfm <= INTEL_P4_WILLAMETTE) || + (c->x86_vfm >= INTEL_CORE_YONAH && c->x86_vfm <= INTEL_IVYBRIDGE)) { + set_cpu_cap(c, X86_FEATURE_CONSTANT_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; - } + switch (c->x86_vfm) { + case INTEL_ATOM_SALTWELL_MID: + case INTEL_ATOM_SALTWELL_TABLET: + case INTEL_ATOM_SILVERMONT_MID: + case INTEL_ATOM_AIRMONT_NP: + set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC_S3); + 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. + * PAT is broken on early family 6 CPUs, the last of which + * is "Yonah" where the erratum is named "AN7": + * + * Page with PAT (Page Attribute Table) Set to USWC + * (Uncacheable Speculative Write Combine) While + * Associated MTRR (Memory Type Range Register) Is UC + * (Uncacheable) May Consolidate to UC * - * Enable PAT WC only on P4, Core 2 or later CPUs. + * Disable PAT and fall back to MTRR on these CPUs. */ - if (c->x86 == 6 && c->x86_model < 15) + if (c->x86_vfm >= INTEL_PENTIUM_PRO && + c->x86_vfm <= INTEL_CORE_YONAH) 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. + * Modern CPUs are generally expected to have a sane fast string + * implementation. However, BIOSes typically have a knob to tweak + * the architectural MISC_ENABLE.FAST_STRING enable bit. + * + * Adhere to the preference and program the Linux-defined fast + * string flag and enhanced fast string capabilities accordingly. */ - 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)) { + if (c->x86_vfm >= INTEL_PENTIUM_M_DOTHAN) { + rdmsrq(MSR_IA32_MISC_ENABLE, misc_enable); + if (misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING) { + /* X86_FEATURE_ERMS is set based on CPUID */ + set_cpu_cap(c, X86_FEATURE_REP_GOOD); + } else { pr_info("Disabled fast string operations\n"); setup_clear_cpu_cap(X86_FEATURE_REP_GOOD); setup_clear_cpu_cap(X86_FEATURE_ERMS); @@ -393,7 +322,7 @@ static void early_init_intel(struct cpuinfo_x86 *c) * 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) { + if (c->x86_vfm == INTEL_QUARK_X1000) { pr_info("Disabling PGE capability bit\n"); setup_clear_cpu_cap(X86_FEATURE_PGE); } @@ -423,9 +352,7 @@ static void bsp_init_intel(struct cpuinfo_x86 *c) 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 && + if (boot_cpu_data.x86_vfm == INTEL_PENTIUM_PRO && boot_cpu_data.x86_stepping < 8) { pr_info("Pentium Pro with Errata#50 detected. Taking evasive action.\n"); return 1; @@ -442,9 +369,8 @@ static void intel_smp_check(struct cpuinfo_x86 *c) /* * Mask B, Pentium, but not Pentium MMX */ - if (c->x86 == 5 && - c->x86_stepping >= 1 && c->x86_stepping <= 4 && - c->x86_model <= 3) { + if (c->x86_vfm >= INTEL_FAM5_START && c->x86_vfm < INTEL_PENTIUM_MMX && + c->x86_stepping >= 1 && c->x86_stepping <= 4) { /* * Remember we have B step Pentia with bugs */ @@ -471,7 +397,7 @@ static void intel_workarounds(struct cpuinfo_x86 *c) * 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) { + if (c->x86_vfm >= INTEL_FAM5_START && c->x86_vfm < INTEL_QUARK_X1000) { static int f00f_workaround_enabled; set_cpu_bug(c, X86_BUG_F00F); @@ -486,7 +412,8 @@ static void intel_workarounds(struct cpuinfo_x86 *c) * 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) + if ((c->x86_vfm == INTEL_PENTIUM_II_KLAMATH && c->x86_stepping < 3) || + c->x86_vfm < INTEL_PENTIUM_II_KLAMATH) clear_cpu_cap(c, X86_FEATURE_SEP); /* @@ -504,7 +431,7 @@ static void intel_workarounds(struct cpuinfo_x86 *c) * 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 (c->x86_vfm == INTEL_P4_WILLAMETTE && 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"); @@ -518,27 +445,20 @@ static void intel_workarounds(struct cpuinfo_x86 *c) * 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 && + if (boot_cpu_has(X86_FEATURE_APIC) && c->x86_vfm == INTEL_PENTIUM_75 && (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 + * MOVSL bulk memory moves can be slow when source and dest are not + * both 8-byte aligned. PII/PIII only like MOVSL with 8-byte alignment. + * + * Set the preferred alignment for Pentium Pro and newer processors, as + * it has only been tested on these. */ - 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 */ + if (c->x86_vfm >= INTEL_PENTIUM_PRO) movsl_mask.mask = 7; - break; - } #endif intel_smp_check(c); @@ -570,7 +490,7 @@ static void init_cpuid_fault(struct cpuinfo_x86 *c) { u64 msr; - if (!rdmsrl_safe(MSR_PLATFORM_INFO, &msr)) { + if (!rdmsrq_safe(MSR_PLATFORM_INFO, &msr)) { if (msr & MSR_PLATFORM_INFO_CPUID_FAULT) set_cpu_cap(c, X86_FEATURE_CPUID_FAULT); } @@ -580,7 +500,7 @@ static void init_intel_misc_features(struct cpuinfo_x86 *c) { u64 msr; - if (rdmsrl_safe(MSR_MISC_FEATURES_ENABLES, &msr)) + if (rdmsrq_safe(MSR_MISC_FEATURES_ENABLES, &msr)) return; /* Clear all MISC features */ @@ -591,11 +511,27 @@ static void init_intel_misc_features(struct cpuinfo_x86 *c) probe_xeon_phi_r3mwait(c); msr = this_cpu_read(msr_misc_features_shadow); - wrmsrl(MSR_MISC_FEATURES_ENABLES, msr); + wrmsrq(MSR_MISC_FEATURES_ENABLES, msr); } -static void split_lock_init(void); -static void bus_lock_init(void); +/* + * This is a list of Intel CPUs that are known to suffer from downclocking when + * ZMM registers (512-bit vectors) are used. On these CPUs, when the kernel + * executes SIMD-optimized code such as cryptography functions or CRCs, it + * should prefer 256-bit (YMM) code to 512-bit (ZMM) code. + */ +static const struct x86_cpu_id zmm_exclusion_list[] = { + X86_MATCH_VFM(INTEL_SKYLAKE_X, 0), + X86_MATCH_VFM(INTEL_ICELAKE_X, 0), + X86_MATCH_VFM(INTEL_ICELAKE_D, 0), + X86_MATCH_VFM(INTEL_ICELAKE, 0), + X86_MATCH_VFM(INTEL_ICELAKE_L, 0), + X86_MATCH_VFM(INTEL_ICELAKE_NNPI, 0), + X86_MATCH_VFM(INTEL_TIGERLAKE_L, 0), + X86_MATCH_VFM(INTEL_TIGERLAKE, 0), + /* Allow Rocket Lake and later, and Sapphire Rapids and later. */ + {}, +}; static void init_intel(struct cpuinfo_x86 *c) { @@ -625,19 +561,20 @@ static void init_intel(struct cpuinfo_x86 *c) 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)) + if (boot_cpu_has(X86_FEATURE_CLFLUSH) && + (c->x86_vfm == INTEL_CORE2_DUNNINGTON || + c->x86_vfm == INTEL_NEHALEM_EX || + c->x86_vfm == INTEL_WESTMERE_EX)) 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))) + if (boot_cpu_has(X86_FEATURE_MWAIT) && + (c->x86_vfm == INTEL_ATOM_GOLDMONT || + c->x86_vfm == INTEL_LUNARLAKE_M)) 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 @@ -672,13 +609,11 @@ static void init_intel(struct cpuinfo_x86 *c) 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 + if (x86_match_cpu(zmm_exclusion_list)) + set_cpu_cap(c, X86_FEATURE_PREFER_YMM); + /* Work around errata */ srat_detect_node(c); @@ -687,7 +622,6 @@ static void init_intel(struct cpuinfo_x86 *c) init_intel_misc_features(c); split_lock_init(); - bus_lock_init(); intel_init_thermal(c); } @@ -701,191 +635,90 @@ static unsigned int intel_size_cache(struct cpuinfo_x86 *c, unsigned int size) * 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)) + if (c->x86_vfm == INTEL_PENTIUM_III_TUALATIN && 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)) + if (c->x86_vfm == INTEL_QUARK_X1000) 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) +static void intel_tlb_lookup(const struct leaf_0x2_table *desc) { - unsigned char k; - if (desc == 0) - return; + short entries = desc->entries; - /* 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) { + switch (desc->t_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; + tlb_lli_4k = max(tlb_lli_4k, entries); + tlb_lld_4k = max(tlb_lld_4k, 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; + tlb_lli_4k = max(tlb_lli_4k, entries); + tlb_lld_4k = max(tlb_lld_4k, entries); + tlb_lli_2m = max(tlb_lli_2m, entries); + tlb_lld_2m = max(tlb_lld_2m, entries); + tlb_lli_4m = max(tlb_lli_4m, entries); + tlb_lld_4m = max(tlb_lld_4m, 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; + tlb_lli_4k = max(tlb_lli_4k, entries); + tlb_lli_2m = max(tlb_lli_2m, entries); + tlb_lli_4m = max(tlb_lli_4m, 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; + tlb_lli_4k = max(tlb_lli_4k, 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; + tlb_lli_4m = max(tlb_lli_4m, 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; + tlb_lli_2m = max(tlb_lli_2m, entries); + tlb_lli_4m = max(tlb_lli_4m, 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; + tlb_lld_4k = max(tlb_lld_4k, 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; + tlb_lld_4m = max(tlb_lld_4m, 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; + tlb_lld_2m = max(tlb_lld_2m, entries); + tlb_lld_4m = max(tlb_lld_4m, 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; + tlb_lld_4k = max(tlb_lld_4k, entries); + tlb_lld_4m = max(tlb_lld_4m, entries); break; + case TLB_DATA_1G_2M_4M: + tlb_lld_2m = max(tlb_lld_2m, TLB_0x63_2M_4M_ENTRIES); + tlb_lld_4m = max(tlb_lld_4m, TLB_0x63_2M_4M_ENTRIES); + fallthrough; case TLB_DATA_1G: - if (tlb_lld_1g[ENTRIES] < intel_tlb_table[k].entries) - tlb_lld_1g[ENTRIES] = intel_tlb_table[k].entries; + tlb_lld_1g = max(tlb_lld_1g, 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; + const struct leaf_0x2_table *desc; + union leaf_0x2_regs regs; + u8 *ptr; 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]); - } + cpuid_leaf_0x2(®s); + for_each_cpuid_0x2_desc(regs, ptr, desc) + intel_tlb_lookup(desc); } static const struct cpu_dev intel_cpu_dev = { @@ -952,394 +785,3 @@ static const struct cpu_dev intel_cpu_dev = { }; 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; -} |