// SPDX-License-Identifier: GPL-2.0 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_X86_64 #include #endif #include "cpu.h" #ifdef CONFIG_X86_LOCAL_APIC #include #include #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; } #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_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); 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; clear_cpu_cap(c, X86_FEATURE_TME); 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 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); } check_memory_type_self_snoop_errata(c); /* * Adjust the number of physical bits early because it affects the * valid bits of the MTRR mask registers. */ if (cpu_has(c, X86_FEATURE_TME)) detect_tme_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 } 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); 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); 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; }