LXR linux/arch/x86/kernel/cpu/match.c

   1// SPDX-License-Identifier: GPL-2.0
   2#include <asm/cpu_device_id.h>
   3#include <asm/cpufeature.h>
   4#include <linux/cpu.h>
   5#include <linux/export.h>
   6#include <linux/slab.h>
   7
   8/**
   9 * x86_match_cpu - match current CPU again an array of x86_cpu_ids
  10 * @match: Pointer to array of x86_cpu_ids. Last entry terminated with
  11 *         {}.
  12 *
  13 * Return the entry if the current CPU matches the entries in the
  14 * passed x86_cpu_id match table. Otherwise NULL.  The match table
  15 * contains vendor (X86_VENDOR_*), family, model and feature bits or
  16 * respective wildcard entries.
  17 *
  18 * A typical table entry would be to match a specific CPU
  19 *
  20 * X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6, INTEL_FAM6_BROADWELL,
  21 *                                    X86_FEATURE_ANY, NULL);
  22 *
  23 * Fields can be wildcarded with %X86_VENDOR_ANY, %X86_FAMILY_ANY,
  24 * %X86_MODEL_ANY, %X86_FEATURE_ANY (except for vendor)
  25 *
  26 * asm/cpu_device_id.h contains a set of useful macros which are shortcuts
  27 * for various common selections. The above can be shortened to:
  28 *
  29 * X86_MATCH_INTEL_FAM6_MODEL(BROADWELL, NULL);
  30 *
  31 * Arrays used to match for this should also be declared using
  32 * MODULE_DEVICE_TABLE(x86cpu, ...)
  33 *
  34 * This always matches against the boot cpu, assuming models and features are
  35 * consistent over all CPUs.
  36 */
  37const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match)
  38{
  39        const struct x86_cpu_id *m;
  40        struct cpuinfo_x86 *c = &boot_cpu_data;
  41
  42        for (m = match;
  43             m->vendor | m->family | m->model | m->steppings | m->feature;
  44             m++) {
  45                if (m->vendor != X86_VENDOR_ANY && c->x86_vendor != m->vendor)
  46                        continue;
  47                if (m->family != X86_FAMILY_ANY && c->x86 != m->family)
  48                        continue;
  49                if (m->model != X86_MODEL_ANY && c->x86_model != m->model)
  50                        continue;
  51                if (m->steppings != X86_STEPPING_ANY &&
  52                    !(BIT(c->x86_stepping) & m->steppings))
  53                        continue;
  54                if (m->feature != X86_FEATURE_ANY && !cpu_has(c, m->feature))
  55                        continue;
  56                return m;
  57        }
  58        return NULL;
  59}
  60EXPORT_SYMBOL(x86_match_cpu);
  61
  62static const struct x86_cpu_desc *
  63x86_match_cpu_with_stepping(const struct x86_cpu_desc *match)
  64{
  65        struct cpuinfo_x86 *c = &boot_cpu_data;
  66        const struct x86_cpu_desc *m;
  67
  68        for (m = match; m->x86_family | m->x86_model; m++) {
  69                if (c->x86_vendor != m->x86_vendor)
  70                        continue;
  71                if (c->x86 != m->x86_family)
  72                        continue;
  73                if (c->x86_model != m->x86_model)
  74                        continue;
  75                if (c->x86_stepping != m->x86_stepping)
  76                        continue;
  77                return m;
  78        }
  79        return NULL;
  80}
  81
  82bool x86_cpu_has_min_microcode_rev(const struct x86_cpu_desc *table)
  83{
  84        const struct x86_cpu_desc *res = x86_match_cpu_with_stepping(table);
  85
  86        if (!res || res->x86_microcode_rev > boot_cpu_data.microcode)
  87                return false;
  88
  89        return true;
  90}
  91EXPORT_SYMBOL_GPL(x86_cpu_has_min_microcode_rev);
  92