arch/x86/kernel/cpu/match.c

   1 #include <asm/cpu_device_id.h>
   2 #include <asm/processor.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  */
  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);
  50
  51 ssize_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
  82 int 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 }