arch/x86/kernel/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_intel.h>
  21 #include <asm/microcode_amd.h>
  22 #include <asm/processor.h>
  23
  24 #define QCHAR(a, b, c, d) ((a) + ((b) << 8) + ((c) << 16) + ((d) << 24))
  25 #define CPUID_INTEL1 QCHAR('G', 'e', 'n', 'u')
  26 #define CPUID_INTEL2 QCHAR('i', 'n', 'e', 'I')
  27 #define CPUID_INTEL3 QCHAR('n', 't', 'e', 'l')
  28 #define CPUID_AMD1 QCHAR('A', 'u', 't', 'h')
  29 #define CPUID_AMD2 QCHAR('e', 'n', 't', 'i')
  30 #define CPUID_AMD3 QCHAR('c', 'A', 'M', 'D')
  31
  32 #define CPUID_IS(a, b, c, ebx, ecx, edx)        \
  33                 (!((ebx ^ (a))|(edx ^ (b))|(ecx ^ (c))))
  34
  35 /*
  36  * In early loading microcode phase on BSP, boot_cpu_data is not set up yet.
  37  * x86_vendor() gets vendor id for BSP.
  38  *
  39  * In 32 bit AP case, accessing boot_cpu_data needs linear address. To simplify
  40  * coding, we still use x86_vendor() to get vendor id for AP.
  41  *
  42  * x86_vendor() gets vendor information directly through cpuid.
  43  */
  44 static int x86_vendor(void)
  45 {
  46         u32 eax = 0x00000000;
  47         u32 ebx, ecx = 0, edx;
  48
  49         native_cpuid(&eax, &ebx, &ecx, &edx);
  50
  51         if (CPUID_IS(CPUID_INTEL1, CPUID_INTEL2, CPUID_INTEL3, ebx, ecx, edx))
  52                 return X86_VENDOR_INTEL;
  53
  54         if (CPUID_IS(CPUID_AMD1, CPUID_AMD2, CPUID_AMD3, ebx, ecx, edx))
  55                 return X86_VENDOR_AMD;
  56
  57         return X86_VENDOR_UNKNOWN;
  58 }
  59
  60 static int x86_family(void)
  61 {
  62         u32 eax = 0x00000001;
  63         u32 ebx, ecx = 0, edx;
  64         int x86;
  65
  66         native_cpuid(&eax, &ebx, &ecx, &edx);
  67
  68         x86 = (eax >> 8) & 0xf;
  69         if (x86 == 15)
  70                 x86 += (eax >> 20) & 0xff;
  71
  72         return x86;
  73 }
  74
  75 void __init load_ucode_bsp(void)
  76 {
  77         int vendor, x86;
  78
  79         if (!have_cpuid_p())
  80                 return;
  81
  82         vendor = x86_vendor();
  83         x86 = x86_family();
  84
  85         switch (vendor) {
  86         case X86_VENDOR_INTEL:
  87                 if (x86 >= 6)
  88                         load_ucode_intel_bsp();
  89                 break;
  90         case X86_VENDOR_AMD:
  91                 if (x86 >= 0x10)
  92                         load_ucode_amd_bsp();
  93                 break;
  94         default:
  95                 break;
  96         }
  97 }
  98
  99 void load_ucode_ap(void)
 100 {
 101         int vendor, x86;
 102
 103         if (!have_cpuid_p())
 104                 return;
 105
 106         vendor = x86_vendor();
 107         x86 = x86_family();
 108
 109         switch (vendor) {
 110         case X86_VENDOR_INTEL:
 111                 if (x86 >= 6)
 112                         load_ucode_intel_ap();
 113                 break;
 114         case X86_VENDOR_AMD:
 115                 if (x86 >= 0x10)
 116                         load_ucode_amd_ap();
 117                 break;
 118         default:
 119                 break;
 120         }
 121 }
 122
 123 int __init save_microcode_in_initrd(void)
 124 {
 125         struct cpuinfo_x86 *c = &boot_cpu_data;
 126
 127         switch (c->x86_vendor) {
 128         case X86_VENDOR_INTEL:
 129                 if (c->x86 >= 6)
 130                         save_microcode_in_initrd_intel();
 131                 break;
 132         case X86_VENDOR_AMD:
 133                 if (c->x86 >= 0x10)
 134                         save_microcode_in_initrd_amd();
 135                 break;
 136         default:
 137                 break;
 138         }
 139
 140         return 0;
 141 }