// 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/thread_info.h>
#include <linux/init.h>
#include <linux/uaccess.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_intel.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>

#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,
};

/*
 * Default to sld_off because most systems do not support split lock detection
 * split_lock_setup() will switch this to sld_warn on systems that support
 * split 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 0;
}
__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 insted 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 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 & (1<<11)))
                        set_cpu_cap(c, X86_FEATURE_BTS);
                if (!(l1 & (1<<12)))
                        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);

        if (tsx_ctrl_state == TSX_CTRL_ENABLE)
                tsx_enable();
        if (tsx_ctrl_state == TSX_CTRL_DISABLE)
                tsx_disable();

        split_lock_init();
}

#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, &regs[0], &regs[1], &regs[2], &regs[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 },
};

static inline bool match_option(const char *arg, int arglen, const char *opt)
{
        int len = strlen(opt);

        return len == arglen && !strncmp(arg, opt, len);
}

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 split_lock_setup(void)
{
        enum split_lock_detect_state state = sld_warn;
        char arg[20];
        int i, ret;

        if (!split_lock_verify_msr(false)) {
                pr_info("MSR access failed: Disabled\n");
                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;
                        }
                }
        }

        switch (state) {
        case sld_off:
                pr_info("disabled\n");
                return;
        case sld_warn:
                pr_info("warning about user-space split_locks\n");
                break;
        case sld_fatal:
                pr_info("sending SIGBUS on user-space split_locks\n");
                break;
        }

        rdmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache);

        if (!split_lock_verify_msr(true)) {
                pr_info("MSR access failed: Disabled\n");
                return;
        }

        sld_state = state;
        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)
{
        if (cpu_model_supports_sld)
                split_lock_verify_msr(sld_state != sld_off);
}

static void split_lock_warn(unsigned long ip)
{
        pr_warn_ratelimited("#AC: %s/%d took a split_lock trap at address: 0x%lx\n",
                            current->comm, current->pid, ip);

        /*
         * Disable the split lock detection for this task so it can make
         * progress and set TIF_SLD so the detection is re-enabled via
         * switch_to_sld() when the task is scheduled out.
         */
        sld_update_msr(false);
        set_tsk_thread_flag(current, TIF_SLD);
}

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);

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;
}

/*
 * This function is called only when switching between tasks with
 * different split-lock detection modes. It sets the MSR for the
 * mode of the new task. This is right most of the time, but since
 * the MSR is shared by hyperthreads on a physical core there can
 * be glitches when the two threads need different modes.
 */
void switch_to_sld(unsigned long tifn)
{
        sld_update_msr(!(tifn & _TIF_SLD));
}

/*
 * Bits in the IA32_CORE_CAPABILITIES are not architectural, so they should
 * only be trusted if it is confirmed that a CPU model implements a
 * specific feature at a particular bit position.
 *
 * The possible driver data field values:
 *
 * - 0: CPU models that are known to have the per-core split-lock detection
 *      feature even though they do not enumerate IA32_CORE_CAPABILITIES.
 *
 * - 1: CPU models which may enumerate IA32_CORE_CAPABILITIES and if so use
 *      bit 5 to enumerate the per-core split-lock detection feature.
 */
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),
        X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT,        1),
        X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_D,      1),
        X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_L,      1),
        X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE_L,         1),
        X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE,           1),
        X86_MATCH_INTEL_FAM6_MODEL(SAPPHIRERAPIDS_X,    1),
        X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE,           1),
        {}
};

void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c)
{
        const struct x86_cpu_id *m;
        u64 ia32_core_caps;

        if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
                return;

        m = x86_match_cpu(split_lock_cpu_ids);
        if (!m)
                return;

        switch (m->driver_data) {
        case 0:
                break;
        case 1:
                if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES))
                        return;
                rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps);
                if (!(ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT))
                        return;
                break;
        default:
                return;
        }

        cpu_model_supports_sld = true;
        split_lock_setup();
}