LXR linux/arch/x86/kernel/microcode_intel

   1/*
   2 *      Intel CPU Microcode Update Driver for Linux
   3 *
   4 *      Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com>
   5 *                         H Peter Anvin" <hpa@zytor.com>
   6 *
   7 *      This driver allows to upgrade microcode on Intel processors
   8 *      belonging to IA-32 family - PentiumPro, Pentium II,
   9 *      Pentium III, Xeon, Pentium 4, etc.
  10 *
  11 *      Reference: Section 8.11 of Volume 3a, IA-32 Intel? Architecture
  12 *      Software Developer's Manual
  13 *      Order Number 253668 or free download from:
  14 *
  15 *      http://developer.intel.com/Assets/PDF/manual/253668.pdf
  16 *
  17 *      For more information, go to http://www.urbanmyth.org/microcode
  18 *
  19 *      This program is free software; you can redistribute it and/or
  20 *      modify it under the terms of the GNU General Public License
  21 *      as published by the Free Software Foundation; either version
  22 *      2 of the License, or (at your option) any later version.
  23 *
  24 */
  25#include <linux/firmware.h>
  26#include <linux/uaccess.h>
  27#include <linux/kernel.h>
  28#include <linux/module.h>
  29
  30#include <asm/microcode_intel.h>
  31#include <asm/processor.h>
  32#include <asm/msr.h>
  33
  34static inline int
  35update_match_cpu(unsigned int csig, unsigned int cpf,
  36                 unsigned int sig, unsigned int pf)
  37{
  38        return (!sigmatch(sig, csig, pf, cpf)) ? 0 : 1;
  39}
  40
  41int
  42update_match_revision(struct microcode_header_intel *mc_header, int rev)
  43{
  44        return (mc_header->rev <= rev) ? 0 : 1;
  45}
  46
  47int microcode_sanity_check(void *mc, int print_err)
  48{
  49        unsigned long total_size, data_size, ext_table_size;
  50        struct microcode_header_intel *mc_header = mc;
  51        struct extended_sigtable *ext_header = NULL;
  52        int sum, orig_sum, ext_sigcount = 0, i;
  53        struct extended_signature *ext_sig;
  54
  55        total_size = get_totalsize(mc_header);
  56        data_size = get_datasize(mc_header);
  57
  58        if (data_size + MC_HEADER_SIZE > total_size) {
  59                if (print_err)
  60                        pr_err("error! Bad data size in microcode data file\n");
  61                return -EINVAL;
  62        }
  63
  64        if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
  65                if (print_err)
  66                        pr_err("error! Unknown microcode update format\n");
  67                return -EINVAL;
  68        }
  69        ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
  70        if (ext_table_size) {
  71                if ((ext_table_size < EXT_HEADER_SIZE)
  72                 || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
  73                        if (print_err)
  74                                pr_err("error! Small exttable size in microcode data file\n");
  75                        return -EINVAL;
  76                }
  77                ext_header = mc + MC_HEADER_SIZE + data_size;
  78                if (ext_table_size != exttable_size(ext_header)) {
  79                        if (print_err)
  80                                pr_err("error! Bad exttable size in microcode data file\n");
  81                        return -EFAULT;
  82                }
  83                ext_sigcount = ext_header->count;
  84        }
  85
  86        /* check extended table checksum */
  87        if (ext_table_size) {
  88                int ext_table_sum = 0;
  89                int *ext_tablep = (int *)ext_header;
  90
  91                i = ext_table_size / DWSIZE;
  92                while (i--)
  93                        ext_table_sum += ext_tablep[i];
  94                if (ext_table_sum) {
  95                        if (print_err)
  96                                pr_warn("aborting, bad extended signature table checksum\n");
  97                        return -EINVAL;
  98                }
  99        }
 100
 101        /* calculate the checksum */
 102        orig_sum = 0;
 103        i = (MC_HEADER_SIZE + data_size) / DWSIZE;
 104        while (i--)
 105                orig_sum += ((int *)mc)[i];
 106        if (orig_sum) {
 107                if (print_err)
 108                        pr_err("aborting, bad checksum\n");
 109                return -EINVAL;
 110        }
 111        if (!ext_table_size)
 112                return 0;
 113        /* check extended signature checksum */
 114        for (i = 0; i < ext_sigcount; i++) {
 115                ext_sig = (void *)ext_header + EXT_HEADER_SIZE +
 116                          EXT_SIGNATURE_SIZE * i;
 117                sum = orig_sum
 118                        - (mc_header->sig + mc_header->pf + mc_header->cksum)
 119                        + (ext_sig->sig + ext_sig->pf + ext_sig->cksum);
 120                if (sum) {
 121                        if (print_err)
 122                                pr_err("aborting, bad checksum\n");
 123                        return -EINVAL;
 124                }
 125        }
 126        return 0;
 127}
 128EXPORT_SYMBOL_GPL(microcode_sanity_check);
 129
 130/*
 131 * return 0 - no update found
 132 * return 1 - found update
 133 */
 134int get_matching_sig(unsigned int csig, int cpf, void *mc, int rev)
 135{
 136        struct microcode_header_intel *mc_header = mc;
 137        struct extended_sigtable *ext_header;
 138        unsigned long total_size = get_totalsize(mc_header);
 139        int ext_sigcount, i;
 140        struct extended_signature *ext_sig;
 141
 142        if (update_match_cpu(csig, cpf, mc_header->sig, mc_header->pf))
 143                return 1;
 144
 145        /* Look for ext. headers: */
 146        if (total_size <= get_datasize(mc_header) + MC_HEADER_SIZE)
 147                return 0;
 148
 149        ext_header = mc + get_datasize(mc_header) + MC_HEADER_SIZE;
 150        ext_sigcount = ext_header->count;
 151        ext_sig = (void *)ext_header + EXT_HEADER_SIZE;
 152
 153        for (i = 0; i < ext_sigcount; i++) {
 154                if (update_match_cpu(csig, cpf, ext_sig->sig, ext_sig->pf))
 155                        return 1;
 156                ext_sig++;
 157        }
 158        return 0;
 159}
 160
 161/*
 162 * return 0 - no update found
 163 * return 1 - found update
 164 */
 165int get_matching_microcode(unsigned int csig, int cpf, void *mc, int rev)
 166{
 167        struct microcode_header_intel *mc_header = mc;
 168
 169        if (!update_match_revision(mc_header, rev))
 170                return 0;
 171
 172        return get_matching_sig(csig, cpf, mc, rev);
 173}
 174EXPORT_SYMBOL_GPL(get_matching_microcode);
 175