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/export.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  */
  31 const 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 }
  49 EXPORT_SYMBOL(x86_match_cpu);