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         if (!have_cpuid_p())
  49                 return X86_VENDOR_UNKNOWN;
  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 void __init load_ucode_bsp(void)
  63 {
  64         int vendor = x86_vendor();
  65
  66         if (vendor == X86_VENDOR_INTEL)
  67                 load_ucode_intel_bsp();
  68 }
  69
  70 void __cpuinit load_ucode_ap(void)
  71 {
  72         int vendor = x86_vendor();
  73
  74         if (vendor == X86_VENDOR_INTEL)
  75                 load_ucode_intel_ap();
  76 }