microcode_intel.c

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/*
 *  Intel CPU Microcode Update Driver for Linux
 *
 *  Copyright (C) 2000-2006 Tigran Aivazian <[email protected]>
 *            2006  Shaohua Li <[email protected]>
 *
 *  This driver allows to upgrade microcode on Intel processors
 *  belonging to IA-32 family - PentiumPro, Pentium II,
 *  Pentium III, Xeon, Pentium 4, etc.
 *
 *  Reference: Section 8.11 of Volume 3a, IA-32 Intel? Architecture
 *  Software Developer's Manual
 *  Order Number 253668 or free download from:
 *
 *  http://developer.intel.com/Assets/PDF/manual/253668.pdf 
 *
 *  For more information, go to http://www.urbanmyth.org/microcode
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 *  1.0 16 Feb 2000, Tigran Aivazian <[email protected]>
 *      Initial release.
 *  1.01    18 Feb 2000, Tigran Aivazian <[email protected]>
 *      Added read() support + cleanups.
 *  1.02    21 Feb 2000, Tigran Aivazian <[email protected]>
 *      Added 'device trimming' support. open(O_WRONLY) zeroes
 *      and frees the saved copy of applied microcode.
 *  1.03    29 Feb 2000, Tigran Aivazian <[email protected]>
 *      Made to use devfs (/dev/cpu/microcode) + cleanups.
 *  1.04    06 Jun 2000, Simon Trimmer <[email protected]>
 *      Added misc device support (now uses both devfs and misc).
 *      Added MICROCODE_IOCFREE ioctl to clear memory.
 *  1.05    09 Jun 2000, Simon Trimmer <[email protected]>
 *      Messages for error cases (non Intel & no suitable microcode).
 *  1.06    03 Aug 2000, Tigran Aivazian <[email protected]>
 *      Removed ->release(). Removed exclusive open and status bitmap.
 *      Added microcode_rwsem to serialize read()/write()/ioctl().
 *      Removed global kernel lock usage.
 *  1.07    07 Sep 2000, Tigran Aivazian <[email protected]>
 *      Write 0 to 0x8B msr and then cpuid before reading revision,
 *      so that it works even if there were no update done by the
 *      BIOS. Otherwise, reading from 0x8B gives junk (which happened
 *      to be 0 on my machine which is why it worked even when I
 *      disabled update by the BIOS)
 *      Thanks to Eric W. Biederman <[email protected]> for the fix.
 *  1.08    11 Dec 2000, Richard Schaal <[email protected]> and
 *               Tigran Aivazian <[email protected]>
 *      Intel Pentium 4 processor support and bugfixes.
 *  1.09    30 Oct 2001, Tigran Aivazian <[email protected]>
 *      Bugfix for HT (Hyper-Threading) enabled processors
 *      whereby processor resources are shared by all logical processors
 *      in a single CPU package.
 *  1.10    28 Feb 2002 Asit K Mallick <[email protected]> and
 *      Tigran Aivazian <[email protected]>,
 *      Serialize updates as required on HT processors due to
 *      speculative nature of implementation.
 *  1.11    22 Mar 2002 Tigran Aivazian <[email protected]>
 *      Fix the panic when writing zero-length microcode chunk.
 *  1.12    29 Sep 2003 Nitin Kamble <[email protected]>,
 *      Jun Nakajima <[email protected]>
 *      Support for the microcode updates in the new format.
 *  1.13    10 Oct 2003 Tigran Aivazian <[email protected]>
 *      Removed ->read() method and obsoleted MICROCODE_IOCFREE ioctl
 *      because we no longer hold a copy of applied microcode
 *      in kernel memory.
 *  1.14    25 Jun 2004 Tigran Aivazian <[email protected]>
 *      Fix sigmatch() macro to handle old CPUs with pf == 0.
 *      Thanks to Stuart Swales for pointing out this bug.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/firmware.h>
#include <linux/uaccess.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/vmalloc.h>

#include <asm/microcode.h>
#include <asm/processor.h>
#include <asm/msr.h>

MODULE_DESCRIPTION("Microcode Update Driver");
MODULE_AUTHOR("Tigran Aivazian <[email protected]>");
MODULE_LICENSE("GPL");

struct microcode_header_intel {
    unsigned int            hdrver;
    unsigned int            rev;
    unsigned int            date;
    unsigned int            sig;
    unsigned int            cksum;
    unsigned int            ldrver;
    unsigned int            pf;
    unsigned int            datasize;
    unsigned int            totalsize;
    unsigned int            reserved[3];
};

struct microcode_intel {
    struct microcode_header_intel hdr;
    unsigned int            bits[0];
};

/* microcode format is extended from prescott processors */
struct extended_signature {
    unsigned int            sig;
    unsigned int            pf;
    unsigned int            cksum;
};

struct extended_sigtable {
    unsigned int            count;
    unsigned int            cksum;
    unsigned int            reserved[3];
    struct extended_signature sigs[0];
};

#define DEFAULT_UCODE_DATASIZE  (2000)
#define MC_HEADER_SIZE      (sizeof(struct microcode_header_intel))
#define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE)
#define EXT_HEADER_SIZE     (sizeof(struct extended_sigtable))
#define EXT_SIGNATURE_SIZE  (sizeof(struct extended_signature))
#define DWSIZE          (sizeof(u32))

#define get_totalsize(mc) \
    (((struct microcode_intel *)mc)->hdr.totalsize ? \
     ((struct microcode_intel *)mc)->hdr.totalsize : \
     DEFAULT_UCODE_TOTALSIZE)

#define get_datasize(mc) \
    (((struct microcode_intel *)mc)->hdr.datasize ? \
     ((struct microcode_intel *)mc)->hdr.datasize : DEFAULT_UCODE_DATASIZE)

#define sigmatch(s1, s2, p1, p2) \
    (((s1) == (s2)) && (((p1) & (p2)) || (((p1) == 0) && ((p2) == 0))))

#define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)

static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
{
    struct cpuinfo_x86 *c = &cpu_data(cpu_num);
    unsigned int val[2];

    memset(csig, 0, sizeof(*csig));

    csig->sig = cpuid_eax(0x00000001);

    if ((c->x86_model >= 5) || (c->x86 > 6)) {
        /* get processor flags from MSR 0x17 */
        rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
        csig->pf = 1 << ((val[1] >> 18) & 7);
    }

    csig->rev = c->microcode;
    pr_info("CPU%d sig=0x%x, pf=0x%x, revision=0x%x\n",
        cpu_num, csig->sig, csig->pf, csig->rev);

    return 0;
}

static inline int update_match_cpu(struct cpu_signature *csig, int sig, int pf)
{
    return (!sigmatch(sig, csig->sig, pf, csig->pf)) ? 0 : 1;
}

static inline int
update_match_revision(struct microcode_header_intel *mc_header, int rev)
{
    return (mc_header->rev <= rev) ? 0 : 1;
}

static int microcode_sanity_check(void *mc)
{
    unsigned long total_size, data_size, ext_table_size;
    struct microcode_header_intel *mc_header = mc;
    struct extended_sigtable *ext_header = NULL;
    int sum, orig_sum, ext_sigcount = 0, i;
    struct extended_signature *ext_sig;

    total_size = get_totalsize(mc_header);
    data_size = get_datasize(mc_header);

    if (data_size + MC_HEADER_SIZE > total_size) {
        pr_err("error! Bad data size in microcode data file\n");
        return -EINVAL;
    }

    if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
        pr_err("error! Unknown microcode update format\n");
        return -EINVAL;
    }
    ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
    if (ext_table_size) {
        if ((ext_table_size < EXT_HEADER_SIZE)
         || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
            pr_err("error! Small exttable size in microcode data file\n");
            return -EINVAL;
        }
        ext_header = mc + MC_HEADER_SIZE + data_size;
        if (ext_table_size != exttable_size(ext_header)) {
            pr_err("error! Bad exttable size in microcode data file\n");
            return -EFAULT;
        }
        ext_sigcount = ext_header->count;
    }

    /* check extended table checksum */
    if (ext_table_size) {
        int ext_table_sum = 0;
        int *ext_tablep = (int *)ext_header;

        i = ext_table_size / DWSIZE;
        while (i--)
            ext_table_sum += ext_tablep[i];
        if (ext_table_sum) {
            pr_warning("aborting, bad extended signature table checksum\n");
            return -EINVAL;
        }
    }

    /* calculate the checksum */
    orig_sum = 0;
    i = (MC_HEADER_SIZE + data_size) / DWSIZE;
    while (i--)
        orig_sum += ((int *)mc)[i];
    if (orig_sum) {
        pr_err("aborting, bad checksum\n");
        return -EINVAL;
    }
    if (!ext_table_size)
        return 0;
    /* check extended signature checksum */
    for (i = 0; i < ext_sigcount; i++) {
        ext_sig = (void *)ext_header + EXT_HEADER_SIZE +
              EXT_SIGNATURE_SIZE * i;
        sum = orig_sum
            - (mc_header->sig + mc_header->pf + mc_header->cksum)
            + (ext_sig->sig + ext_sig->pf + ext_sig->cksum);
        if (sum) {
            pr_err("aborting, bad checksum\n");
            return -EINVAL;
        }
    }
    return 0;
}

/*
 * return 0 - no update found
 * return 1 - found update
 */
static int
get_matching_microcode(struct cpu_signature *cpu_sig, void *mc, int rev)
{
    struct microcode_header_intel *mc_header = mc;
    struct extended_sigtable *ext_header;
    unsigned long total_size = get_totalsize(mc_header);
    int ext_sigcount, i;
    struct extended_signature *ext_sig;

    if (!update_match_revision(mc_header, rev))
        return 0;

    if (update_match_cpu(cpu_sig, mc_header->sig, mc_header->pf))
        return 1;

    /* Look for ext. headers: */
    if (total_size <= get_datasize(mc_header) + MC_HEADER_SIZE)
        return 0;

    ext_header = mc + get_datasize(mc_header) + MC_HEADER_SIZE;
    ext_sigcount = ext_header->count;
    ext_sig = (void *)ext_header + EXT_HEADER_SIZE;

    for (i = 0; i < ext_sigcount; i++) {
        if (update_match_cpu(cpu_sig, ext_sig->sig, ext_sig->pf))
            return 1;
        ext_sig++;
    }
    return 0;
}

static int apply_microcode(int cpu)
{
    struct microcode_intel *mc_intel;
    struct ucode_cpu_info *uci;
    unsigned int val[2];
    int cpu_num = raw_smp_processor_id();
    struct cpuinfo_x86 *c = &cpu_data(cpu_num);

    uci = ucode_cpu_info + cpu;
    mc_intel = uci->mc;

    /* We should bind the task to the CPU */
    BUG_ON(cpu_num != cpu);

    if (mc_intel == NULL)
        return 0;

    /* write microcode via MSR 0x79 */
    wrmsr(MSR_IA32_UCODE_WRITE,
          (unsigned long) mc_intel->bits,
          (unsigned long) mc_intel->bits >> 16 >> 16);
    wrmsr(MSR_IA32_UCODE_REV, 0, 0);

    /* As documented in the SDM: Do a CPUID 1 here */
    sync_core();

    /* get the current revision from MSR 0x8B */
    rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);

    if (val[1] != mc_intel->hdr.rev) {
        pr_err("CPU%d update to revision 0x%x failed\n",
               cpu_num, mc_intel->hdr.rev);
        return -1;
    }
    pr_info("CPU%d updated to revision 0x%x, date = %04x-%02x-%02x\n",
        cpu_num, val[1],
        mc_intel->hdr.date & 0xffff,
        mc_intel->hdr.date >> 24,
        (mc_intel->hdr.date >> 16) & 0xff);

    uci->cpu_sig.rev = val[1];
    c->microcode = val[1];

    return 0;
}

static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
                int (*get_ucode_data)(void *, const void *, size_t))
{
    struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
    u8 *ucode_ptr = data, *new_mc = NULL, *mc = NULL;
    int new_rev = uci->cpu_sig.rev;
    unsigned int leftover = size;
    enum ucode_state state = UCODE_OK;
    unsigned int curr_mc_size = 0;

    while (leftover) {
        struct microcode_header_intel mc_header;
        unsigned int mc_size;

        if (get_ucode_data(&mc_header, ucode_ptr, sizeof(mc_header)))
            break;

        mc_size = get_totalsize(&mc_header);
        if (!mc_size || mc_size > leftover) {
            pr_err("error! Bad data in microcode data file\n");
            break;
        }

        /* For performance reasons, reuse mc area when possible */
        if (!mc || mc_size > curr_mc_size) {
            vfree(mc);
            mc = vmalloc(mc_size);
            if (!mc)
                break;
            curr_mc_size = mc_size;
        }

        if (get_ucode_data(mc, ucode_ptr, mc_size) ||
            microcode_sanity_check(mc) < 0) {
            break;
        }

        if (get_matching_microcode(&uci->cpu_sig, mc, new_rev)) {
            vfree(new_mc);
            new_rev = mc_header.rev;
            new_mc  = mc;
            mc = NULL;  /* trigger new vmalloc */
        }

        ucode_ptr += mc_size;
        leftover  -= mc_size;
    }

    vfree(mc);

    if (leftover) {
        vfree(new_mc);
        state = UCODE_ERROR;
        goto out;
    }

    if (!new_mc) {
        state = UCODE_NFOUND;
        goto out;
    }

    vfree(uci->mc);
    uci->mc = (struct microcode_intel *)new_mc;

    pr_debug("CPU%d found a matching microcode update with version 0x%x (current=0x%x)\n",
         cpu, new_rev, uci->cpu_sig.rev);
out:
    return state;
}

static int get_ucode_fw(void *to, const void *from, size_t n)
{
    memcpy(to, from, n);
    return 0;
}

static enum ucode_state request_microcode_fw(int cpu, struct device *device,
                         bool refresh_fw)
{
    char name[30];
    struct cpuinfo_x86 *c = &cpu_data(cpu);
    const struct firmware *firmware;
    enum ucode_state ret;

    sprintf(name, "intel-ucode/%02x-%02x-%02x",
        c->x86, c->x86_model, c->x86_mask);

    if (request_firmware(&firmware, name, device)) {
        pr_debug("data file %s load failed\n", name);
        return UCODE_NFOUND;
    }

    ret = generic_load_microcode(cpu, (void *)firmware->data,
                     firmware->size, &get_ucode_fw);

    release_firmware(firmware);

    return ret;
}

static int get_ucode_user(void *to, const void *from, size_t n)
{
    return copy_from_user(to, from, n);
}

static enum ucode_state
request_microcode_user(int cpu, const void __user *buf, size_t size)
{
    return generic_load_microcode(cpu, (void *)buf, size, &get_ucode_user);
}

static void microcode_fini_cpu(int cpu)
{
    struct ucode_cpu_info *uci = ucode_cpu_info + cpu;

    vfree(uci->mc);
    uci->mc = NULL;
}

static struct microcode_ops microcode_intel_ops = {
    .request_microcode_user       = request_microcode_user,
    .request_microcode_fw             = request_microcode_fw,
    .collect_cpu_info                 = collect_cpu_info,
    .apply_microcode                  = apply_microcode,
    .microcode_fini_cpu               = microcode_fini_cpu,
};

struct microcode_ops * __init init_intel_microcode(void)
{
    struct cpuinfo_x86 *c = &cpu_data(0);

    if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
        cpu_has(c, X86_FEATURE_IA64)) {
        pr_err("Intel CPU family 0x%x not supported\n", c->x86);
        return NULL;
    }

    return &microcode_intel_ops;
}