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_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->feature != X86_FEATURE_ANY && !cpu_has(c, m->feature))
52 continue;
53 return m;
54 }
55 return NULL;
56 }
57 EXPORT_SYMBOL(x86_match_cpu);
58
59 static const struct x86_cpu_desc *
60 x86_match_cpu_with_stepping(const struct x86_cpu_desc *match)
61 {
62 struct cpuinfo_x86 *c = &boot_cpu_data;
63 const struct x86_cpu_desc *m;
64
65 for (m = match; m->x86_family | m->x86_model; m++) {
66 if (c->x86_vendor != m->x86_vendor)
67 continue;
68 if (c->x86 != m->x86_family)
69 continue;
70 if (c->x86_model != m->x86_model)
71 continue;
72 if (c->x86_stepping != m->x86_stepping)
73 continue;
74 return m;
75 }
76 return NULL;
77 }
78
79 bool x86_cpu_has_min_microcode_rev(const struct x86_cpu_desc *table)
80 {
81 const struct x86_cpu_desc *res = x86_match_cpu_with_stepping(table);
82
83 if (!res || res->x86_microcode_rev > boot_cpu_data.microcode)
84 return false;
85
86 return true;
87 }
88 EXPORT_SYMBOL_GPL(x86_cpu_has_min_microcode_rev);
89
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