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/processor.h>
  22
  23 #define QCHAR(a, b, c, d) ((a) + ((b) << 8) + ((c) << 16) + ((d) << 24))
  24 #define CPUID_INTEL1 QCHAR('G', 'e', 'n', 'u')
  25 #define CPUID_INTEL2 QCHAR('i', 'n', 'e', 'I')
  26 #define CPUID_INTEL3 QCHAR('n', 't', 'e', 'l')
  27 #define CPUID_AMD1 QCHAR('A', 'u', 't', 'h')
  28 #define CPUID_AMD2 QCHAR('e', 'n', 't', 'i')
  29 #define CPUID_AMD3 QCHAR('c', 'A', 'M', 'D')
  30
  31 #define CPUID_IS(a, b, c, ebx, ecx, edx)        \
  32                 (!((ebx ^ (a))|(edx ^ (b))|(ecx ^ (c))))
  33
  34 /*
  35  * In early loading microcode phase on BSP, boot_cpu_data is not set up yet.
  36  * x86_vendor() gets vendor id for BSP.
  37  *
  38  * In 32 bit AP case, accessing boot_cpu_data needs linear address. To simplify
  39  * coding, we still use x86_vendor() to get vendor id for AP.
  40  *
  41  * x86_vendor() gets vendor information directly through cpuid.
  42  */
  43 static int __cpuinit x86_vendor(void)
  44 {
  45         u32 eax = 0x00000000;
  46         u32 ebx, ecx = 0, edx;
  47
  48         native_cpuid(&eax, &ebx, &ecx, &edx);
  49
  50         if (CPUID_IS(CPUID_INTEL1, CPUID_INTEL2, CPUID_INTEL3, ebx, ecx, edx))
  51                 return X86_VENDOR_INTEL;
  52
  53         if (CPUID_IS(CPUID_AMD1, CPUID_AMD2, CPUID_AMD3, ebx, ecx, edx))
  54                 return X86_VENDOR_AMD;
  55
  56         return X86_VENDOR_UNKNOWN;
  57 }
  58
  59 static int __cpuinit x86_family(void)
  60 {
  61         u32 eax = 0x00000001;
  62         u32 ebx, ecx = 0, edx;
  63         int x86;
  64
  65         native_cpuid(&eax, &ebx, &ecx, &edx);
  66
  67         x86 = (eax >> 8) & 0xf;
  68         if (x86 == 15)
  69                 x86 += (eax >> 20) & 0xff;
  70
  71         return x86;
  72 }
  73
  74 void __init load_ucode_bsp(void)
  75 {
  76         int vendor, x86;
  77
  78         if (!have_cpuid_p())
  79                 return;
  80
  81         vendor = x86_vendor();
  82         x86 = x86_family();
  83
  84         if (vendor == X86_VENDOR_INTEL && x86 >= 6)
  85                 load_ucode_intel_bsp();
  86 }
  87
  88 void __cpuinit load_ucode_ap(void)
  89 {
  90         int vendor, x86;
  91
  92         if (!have_cpuid_p())
  93                 return;
  94
  95         vendor = x86_vendor();
  96         x86 = x86_family();
  97
  98         if (vendor == X86_VENDOR_INTEL && x86 >= 6)
  99                 load_ucode_intel_ap();
 100 }