xref: /linux/arch/x86/kernel/cpu/match.c (revision 59e6295fac26b8e85c1ea859cdd89fa1e47519d7)
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 against 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  *
20  * X86_MATCH_VFM_FEATURE(INTEL_BROADWELL, X86_FEATURE_ANY, NULL);
21  *
22  * Fields can be wildcarded with %X86_VENDOR_ANY, %X86_FAMILY_ANY,
23  * %X86_MODEL_ANY, %X86_FEATURE_ANY (except for vendor)
24  *
25  * asm/cpu_device_id.h contains a set of useful macros which are shortcuts
26  * for various common selections. The above can be shortened to:
27  *
28  * X86_MATCH_VFM(INTEL_BROADWELL, NULL);
29  *
30  * Arrays used to match for this should also be declared using
31  * MODULE_DEVICE_TABLE(x86cpu, ...)
32  *
33  * This always matches against the boot cpu, assuming models and features are
34  * consistent over all CPUs.
35  */
36 const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match)
37 {
38 	const struct x86_cpu_id *m;
39 	struct cpuinfo_x86 *c = &boot_cpu_data;
40 
41 	for (m = match; m->flags & X86_CPU_ID_FLAG_ENTRY_VALID; m++) {
42 		if (m->vendor != X86_VENDOR_ANY && c->x86_vendor != m->vendor)
43 			continue;
44 		if (m->family != X86_FAMILY_ANY && c->x86 != m->family)
45 			continue;
46 		if (m->model != X86_MODEL_ANY && c->x86_model != m->model)
47 			continue;
48 		if (m->steppings != X86_STEPPING_ANY &&
49 		    !(BIT(c->x86_stepping) & m->steppings))
50 			continue;
51 		if (m->platform_mask != X86_PLATFORM_ANY &&
52 		    !(BIT(c->intel_platform_id) & m->platform_mask))
53 			continue;
54 		if (m->feature != X86_FEATURE_ANY && !cpu_has(c, m->feature))
55 			continue;
56 		if (m->type != X86_CPU_TYPE_ANY && c->topo.cpu_type != m->type)
57 			continue;
58 		return m;
59 	}
60 	return NULL;
61 }
62 EXPORT_SYMBOL(x86_match_cpu);
63 
64 bool x86_match_min_microcode_rev(const struct x86_cpu_id *table)
65 {
66 	const struct x86_cpu_id *res = x86_match_cpu(table);
67 
68 	if (!res || res->driver_data > boot_cpu_data.microcode)
69 		return false;
70 
71 	return true;
72 }
73 EXPORT_SYMBOL_GPL(x86_match_min_microcode_rev);
74