xref: /openbmc/linux/arch/x86/kernel/cpu/match.c (revision 0883c2c0)
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  */
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