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 *
20 * X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6, INTEL_FAM6_BROADWELL,
21 *				      X86_FEATURE_ANY, NULL);
22 *
23 * Fields can be wildcarded with %X86_VENDOR_ANY, %X86_FAMILY_ANY,
24 * %X86_MODEL_ANY, %X86_FEATURE_ANY (except for vendor)
25 *
26 * asm/cpu_device_id.h contains a set of useful macros which are shortcuts
27 * for various common selections. The above can be shortened to:
28 *
29 * X86_MATCH_INTEL_FAM6_MODEL(BROADWELL, NULL);
30 *
31 * Arrays used to match for this should also be declared using
32 * MODULE_DEVICE_TABLE(x86cpu, ...)
33 *
34 * This always matches against the boot cpu, assuming models and features are
35 * consistent over all CPUs.
36 */
37const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match)
38{
39	const struct x86_cpu_id *m;
40	struct cpuinfo_x86 *c = &boot_cpu_data;
41
42	for (m = match;
43	     m->vendor | m->family | m->model | m->steppings | m->feature;
44	     m++) {
45		if (m->vendor != X86_VENDOR_ANY && c->x86_vendor != m->vendor)
46			continue;
47		if (m->family != X86_FAMILY_ANY && c->x86 != m->family)
48			continue;
49		if (m->model != X86_MODEL_ANY && c->x86_model != m->model)
50			continue;
51		if (m->steppings != X86_STEPPING_ANY &&
52		    !(BIT(c->x86_stepping) & m->steppings))
53			continue;
54		if (m->feature != X86_FEATURE_ANY && !cpu_has(c, m->feature))
55			continue;
56		return m;
57	}
58	return NULL;
59}
60EXPORT_SYMBOL(x86_match_cpu);
61
62static const struct x86_cpu_desc *
63x86_match_cpu_with_stepping(const struct x86_cpu_desc *match)
64{
65	struct cpuinfo_x86 *c = &boot_cpu_data;
66	const struct x86_cpu_desc *m;
67
68	for (m = match; m->x86_family | m->x86_model; m++) {
69		if (c->x86_vendor != m->x86_vendor)
70			continue;
71		if (c->x86 != m->x86_family)
72			continue;
73		if (c->x86_model != m->x86_model)
74			continue;
75		if (c->x86_stepping != m->x86_stepping)
76			continue;
77		return m;
78	}
79	return NULL;
80}
81
82bool x86_cpu_has_min_microcode_rev(const struct x86_cpu_desc *table)
83{
84	const struct x86_cpu_desc *res = x86_match_cpu_with_stepping(table);
85
86	if (!res || res->x86_microcode_rev > boot_cpu_data.microcode)
87		return false;
88
89	return true;
90}
91EXPORT_SYMBOL_GPL(x86_cpu_has_min_microcode_rev);
92