xref: /openbmc/linux/arch/x86/kernel/cpu/match.c (revision e3b9f1e8)
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  * { X86_VENDOR_INTEL, 6, 0x12 }
20  * or to match a specific CPU feature
21  * { X86_FEATURE_MATCH(X86_FEATURE_FOOBAR) }
22  *
23  * Fields can be wildcarded with %X86_VENDOR_ANY, %X86_FAMILY_ANY,
24  * %X86_MODEL_ANY, %X86_FEATURE_ANY or 0 (except for vendor)
25  *
26  * Arrays used to match for this should also be declared using
27  * MODULE_DEVICE_TABLE(x86cpu, ...)
28  *
29  * This always matches against the boot cpu, assuming models and features are
30  * consistent over all CPUs.
31  */
32 const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match)
33 {
34 	const struct x86_cpu_id *m;
35 	struct cpuinfo_x86 *c = &boot_cpu_data;
36 
37 	for (m = match; m->vendor | m->family | m->model | m->feature; m++) {
38 		if (m->vendor != X86_VENDOR_ANY && c->x86_vendor != m->vendor)
39 			continue;
40 		if (m->family != X86_FAMILY_ANY && c->x86 != m->family)
41 			continue;
42 		if (m->model != X86_MODEL_ANY && c->x86_model != m->model)
43 			continue;
44 		if (m->feature != X86_FEATURE_ANY && !cpu_has(c, m->feature))
45 			continue;
46 		return m;
47 	}
48 	return NULL;
49 }
50 EXPORT_SYMBOL(x86_match_cpu);
51