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

   1#include <asm/cpu_device_id.h>
   2#include <asm/cpufeature.h>
   3#include <linux/cpu.h>
   4#include <linux/module.h>
   5#include <linux/slab.h>
   6
   7/**
   8 * x86_match_cpu - match current CPU again an array of x86_cpu_ids
   9 * @match: Pointer to array of x86_cpu_ids. Last entry terminated with
  10 *         {}.
  11 *
  12 * Return the entry if the current CPU matches the entries in the
  13 * passed x86_cpu_id match table. Otherwise NULL.  The match table
  14 * contains vendor (X86_VENDOR_*), family, model and feature bits or
  15 * respective wildcard entries.
  16 *
  17 * A typical table entry would be to match a specific CPU
  18 * { X86_VENDOR_INTEL, 6, 0x12 }
  19 * or to match a specific CPU feature
  20 * { X86_FEATURE_MATCH(X86_FEATURE_FOOBAR) }
  21 *
  22 * Fields can be wildcarded with %X86_VENDOR_ANY, %X86_FAMILY_ANY,
  23 * %X86_MODEL_ANY, %X86_FEATURE_ANY or 0 (except for vendor)
  24 *
  25 * Arrays used to match for this should also be declared using
  26 * MODULE_DEVICE_TABLE(x86cpu, ...)
  27 *
  28 * This always matches against the boot cpu, assuming models and features are
  29 * consistent over all CPUs.
  30 */
  31const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match)
  32{
  33        const struct x86_cpu_id *m;
  34        struct cpuinfo_x86 *c = &boot_cpu_data;
  35
  36        for (m = match; m->vendor | m->family | m->model | m->feature; m++) {
  37                if (m->vendor != X86_VENDOR_ANY && c->x86_vendor != m->vendor)
  38                        continue;
  39                if (m->family != X86_FAMILY_ANY && c->x86 != m->family)
  40                        continue;
  41                if (m->model != X86_MODEL_ANY && c->x86_model != m->model)
  42                        continue;
  43                if (m->feature != X86_FEATURE_ANY && !cpu_has(c, m->feature))
  44                        continue;
  45                return m;
  46        }
  47        return NULL;
  48}
  49EXPORT_SYMBOL(x86_match_cpu);
  50
  51ssize_t arch_print_cpu_modalias(struct device *dev,
  52                                struct device_attribute *attr,
  53                                char *bufptr)
  54{
  55        int size = PAGE_SIZE;
  56        int i, n;
  57        char *buf = bufptr;
  58
  59        n = snprintf(buf, size, "x86cpu:vendor:%04X:family:%04X:"
  60                     "model:%04X:feature:",
  61                boot_cpu_data.x86_vendor,
  62                boot_cpu_data.x86,
  63                boot_cpu_data.x86_model);
  64        size -= n;
  65        buf += n;
  66        size -= 1;
  67        for (i = 0; i < NCAPINTS*32; i++) {
  68                if (boot_cpu_has(i)) {
  69                        n = snprintf(buf, size, ",%04X", i);
  70                        if (n >= size) {
  71                                WARN(1, "x86 features overflow page\n");
  72                                break;
  73                        }
  74                        size -= n;
  75                        buf += n;
  76                }
  77        }
  78        *buf++ = '\n';
  79        return buf - bufptr;
  80}
  81
  82int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env)
  83{
  84        char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
  85        if (buf) {
  86                arch_print_cpu_modalias(NULL, NULL, buf);
  87                add_uevent_var(env, "MODALIAS=%s", buf);
  88                kfree(buf);
  89        }
  90        return 0;
  91}
  92
  93static const struct x86_cpu_desc *
  94x86_match_cpu_with_stepping(const struct x86_cpu_desc *match)
  95{
  96        struct cpuinfo_x86 *c = &boot_cpu_data;
  97        const struct x86_cpu_desc *m;
  98
  99        for (m = match; m->x86_family | m->x86_model; m++) {
 100                if (c->x86_vendor != m->x86_vendor)
 101                        continue;
 102                if (c->x86 != m->x86_family)
 103                        continue;
 104                if (c->x86_model != m->x86_model)
 105                        continue;
 106                if (c->x86_mask != m->x86_stepping)
 107                        continue;
 108                return m;
 109        }
 110        return NULL;
 111}
 112
 113bool x86_cpu_has_min_microcode_rev(const struct x86_cpu_desc *table)
 114{
 115        const struct x86_cpu_desc *res = x86_match_cpu_with_stepping(table);
 116
 117        if (!res || res->x86_microcode_rev > boot_cpu_data.microcode)
 118                return false;
 119
 120        return true;
 121}
 122EXPORT_SYMBOL_GPL(x86_cpu_has_min_microcode_rev);
 123