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 */
x86_match_cpu(const struct x86_cpu_id * match)37 const 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; m->flags & X86_CPU_ID_FLAG_ENTRY_VALID; m++) {
43 if (m->vendor != X86_VENDOR_ANY && c->x86_vendor != m->vendor)
44 continue;
45 if (m->family != X86_FAMILY_ANY && c->x86 != m->family)
46 continue;
47 if (m->model != X86_MODEL_ANY && c->x86_model != m->model)
48 continue;
49 if (m->steppings != X86_STEPPING_ANY &&
50 !(BIT(c->x86_stepping) & m->steppings))
51 continue;
52 if (m->feature != X86_FEATURE_ANY && !cpu_has(c, m->feature))
53 continue;
54 return m;
55 }
56 return NULL;
57 }
58 EXPORT_SYMBOL(x86_match_cpu);
59
60 static const struct x86_cpu_desc *
x86_match_cpu_with_stepping(const struct x86_cpu_desc * match)61 x86_match_cpu_with_stepping(const struct x86_cpu_desc *match)
62 {
63 struct cpuinfo_x86 *c = &boot_cpu_data;
64 const struct x86_cpu_desc *m;
65
66 for (m = match; m->x86_family | m->x86_model; m++) {
67 if (c->x86_vendor != m->x86_vendor)
68 continue;
69 if (c->x86 != m->x86_family)
70 continue;
71 if (c->x86_model != m->x86_model)
72 continue;
73 if (c->x86_stepping != m->x86_stepping)
74 continue;
75 return m;
76 }
77 return NULL;
78 }
79
x86_cpu_has_min_microcode_rev(const struct x86_cpu_desc * table)80 bool x86_cpu_has_min_microcode_rev(const struct x86_cpu_desc *table)
81 {
82 const struct x86_cpu_desc *res = x86_match_cpu_with_stepping(table);
83
84 if (!res || res->x86_microcode_rev > boot_cpu_data.microcode)
85 return false;
86
87 return true;
88 }
89 EXPORT_SYMBOL_GPL(x86_cpu_has_min_microcode_rev);
90