arch/x86/kernel/cpu/microcode/core_early.c

   1 /*
   2  *      X86 CPU microcode early update 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 early 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 9.11 of Volume 3, IA-32 Intel Architecture
  12  *      Software Developer's Manual.
  13  *
  14  *      This program is free software; you can redistribute it and/or
  15  *      modify it under the terms of the GNU General Public License
  16  *      as published by the Free Software Foundation; either version
  17  *      2 of the License, or (at your option) any later version.
  18  */
  19 #include <linux/module.h>
  20 #include <asm/microcode.h>
  21 #include <asm/microcode_intel.h>
  22 #include <asm/microcode_amd.h>
  23 #include <asm/processor.h>
  24 #include <asm/cmdline.h>
  25
  26 #define QCHAR(a, b, c, d) ((a) + ((b) << 8) + ((c) << 16) + ((d) << 24))
  27 #define CPUID_INTEL1 QCHAR('G', 'e', 'n', 'u')
  28 #define CPUID_INTEL2 QCHAR('i', 'n', 'e', 'I')
  29 #define CPUID_INTEL3 QCHAR('n', 't', 'e', 'l')
  30 #define CPUID_AMD1 QCHAR('A', 'u', 't', 'h')
  31 #define CPUID_AMD2 QCHAR('e', 'n', 't', 'i')
  32 #define CPUID_AMD3 QCHAR('c', 'A', 'M', 'D')
  33
  34 #define CPUID_IS(a, b, c, ebx, ecx, edx)        \
  35                 (!((ebx ^ (a))|(edx ^ (b))|(ecx ^ (c))))
  36
  37 /*
  38  * In early loading microcode phase on BSP, boot_cpu_data is not set up yet.
  39  * x86_vendor() gets vendor id for BSP.
  40  *
  41  * In 32 bit AP case, accessing boot_cpu_data needs linear address. To simplify
  42  * coding, we still use x86_vendor() to get vendor id for AP.
  43  *
  44  * x86_vendor() gets vendor information directly through cpuid.
  45  */
  46 static int x86_vendor(void)
  47 {
  48         u32 eax = 0x00000000;
  49         u32 ebx, ecx = 0, edx;
  50
  51         native_cpuid(&eax, &ebx, &ecx, &edx);
  52
  53         if (CPUID_IS(CPUID_INTEL1, CPUID_INTEL2, CPUID_INTEL3, ebx, ecx, edx))
  54                 return X86_VENDOR_INTEL;
  55
  56         if (CPUID_IS(CPUID_AMD1, CPUID_AMD2, CPUID_AMD3, ebx, ecx, edx))
  57                 return X86_VENDOR_AMD;
  58
  59         return X86_VENDOR_UNKNOWN;
  60 }
  61
  62 static int x86_family(void)
  63 {
  64         u32 eax = 0x00000001;
  65         u32 ebx, ecx = 0, edx;
  66         int x86;
  67
  68         native_cpuid(&eax, &ebx, &ecx, &edx);
  69
  70         x86 = (eax >> 8) & 0xf;
  71         if (x86 == 15)
  72                 x86 += (eax >> 20) & 0xff;
  73
  74         return x86;
  75 }
  76
  77 static bool __init check_loader_disabled_bsp(void)
  78 {
  79 #ifdef CONFIG_X86_32
  80         const char *cmdline = (const char *)__pa_nodebug(boot_command_line);
  81         const char *opt     = "dis_ucode_ldr";
  82         const char *option  = (const char *)__pa_nodebug(opt);
  83         bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr);
  84
  85 #else /* CONFIG_X86_64 */
  86         const char *cmdline = boot_command_line;
  87         const char *option  = "dis_ucode_ldr";
  88         bool *res = &dis_ucode_ldr;
  89 #endif
  90
  91         if (cmdline_find_option_bool(cmdline, option))
  92                 *res = true;
  93
  94         return *res;
  95 }
  96
  97 void __init load_ucode_bsp(void)
  98 {
  99         int vendor, x86;
 100
 101         if (check_loader_disabled_bsp())
 102                 return;
 103
 104         if (!have_cpuid_p())
 105                 return;
 106
 107         vendor = x86_vendor();
 108         x86 = x86_family();
 109
 110         switch (vendor) {
 111         case X86_VENDOR_INTEL:
 112                 if (x86 >= 6)
 113                         load_ucode_intel_bsp();
 114                 break;
 115         case X86_VENDOR_AMD:
 116                 if (x86 >= 0x10)
 117                         load_ucode_amd_bsp();
 118                 break;
 119         default:
 120                 break;
 121         }
 122 }
 123
 124 static bool check_loader_disabled_ap(void)
 125 {
 126 #ifdef CONFIG_X86_32
 127         return *((bool *)__pa_nodebug(&dis_ucode_ldr));
 128 #else
 129         return dis_ucode_ldr;
 130 #endif
 131 }
 132
 133 void load_ucode_ap(void)
 134 {
 135         int vendor, x86;
 136
 137         if (check_loader_disabled_ap())
 138                 return;
 139
 140         if (!have_cpuid_p())
 141                 return;
 142
 143         vendor = x86_vendor();
 144         x86 = x86_family();
 145
 146         switch (vendor) {
 147         case X86_VENDOR_INTEL:
 148                 if (x86 >= 6)
 149                         load_ucode_intel_ap();
 150                 break;
 151         case X86_VENDOR_AMD:
 152                 if (x86 >= 0x10)
 153                         load_ucode_amd_ap();
 154                 break;
 155         default:
 156                 break;
 157         }
 158 }
 159
 160 int __init save_microcode_in_initrd(void)
 161 {
 162         struct cpuinfo_x86 *c = &boot_cpu_data;
 163
 164         switch (c->x86_vendor) {
 165         case X86_VENDOR_INTEL:
 166                 if (c->x86 >= 6)
 167                         save_microcode_in_initrd_intel();
 168                 break;
 169         case X86_VENDOR_AMD:
 170                 if (c->x86 >= 0x10)
 171                         save_microcode_in_initrd_amd();
 172                 break;
 173         default:
 174                 break;
 175         }
 176
 177         return 0;
 178 }