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_vendor_cpu_type - helper function to match the hardware defined
10 * cpu-type for a single entry in the x86_cpu_id
11 * table. Note, this function does not match the
12 * generic cpu-types TOPO_CPU_TYPE_EFFICIENCY and
13 * TOPO_CPU_TYPE_PERFORMANCE.
14 * @c: Pointer to the cpuinfo_x86 structure of the CPU to match.
15 * @m: Pointer to the x86_cpu_id entry to match against.
16 *
17 * Return: true if the cpu-type matches, false otherwise.
18 */
19static bool x86_match_vendor_cpu_type(struct cpuinfo_x86 *c, const struct x86_cpu_id *m)
20{
21 if (m->type == X86_CPU_TYPE_ANY)
22 return true;
23
24 /* Hybrid CPUs are special, they are assumed to match all cpu-types */
25 if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
26 return true;
27
28 if (c->x86_vendor == X86_VENDOR_INTEL)
29 return m->type == c->topo.intel_type;
30 if (c->x86_vendor == X86_VENDOR_AMD)
31 return m->type == c->topo.amd_type;
32
33 return false;
34}
35
36/**
37 * x86_match_cpu - match current CPU against an array of x86_cpu_ids
38 * @match: Pointer to array of x86_cpu_ids. Last entry terminated with
39 * {}.
40 *
41 * Return the entry if the current CPU matches the entries in the
42 * passed x86_cpu_id match table. Otherwise NULL. The match table
43 * contains vendor (X86_VENDOR_*), family, model and feature bits or
44 * respective wildcard entries.
45 *
46 * A typical table entry would be to match a specific CPU
47 *
48 * X86_MATCH_VFM_FEATURE(INTEL_BROADWELL, X86_FEATURE_ANY, NULL);
49 *
50 * Fields can be wildcarded with %X86_VENDOR_ANY, %X86_FAMILY_ANY,
51 * %X86_MODEL_ANY, %X86_FEATURE_ANY (except for vendor)
52 *
53 * asm/cpu_device_id.h contains a set of useful macros which are shortcuts
54 * for various common selections. The above can be shortened to:
55 *
56 * X86_MATCH_VFM(INTEL_BROADWELL, NULL);
57 *
58 * Arrays used to match for this should also be declared using
59 * MODULE_DEVICE_TABLE(x86cpu, ...)
60 *
61 * This always matches against the boot cpu, assuming models and features are
62 * consistent over all CPUs.
63 */
64const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match)
65{
66 const struct x86_cpu_id *m;
67 struct cpuinfo_x86 *c = &boot_cpu_data;
68
69 for (m = match; m->flags & X86_CPU_ID_FLAG_ENTRY_VALID; m++) {
70 if (m->vendor != X86_VENDOR_ANY && c->x86_vendor != m->vendor)
71 continue;
72 if (m->family != X86_FAMILY_ANY && c->x86 != m->family)
73 continue;
74 if (m->model != X86_MODEL_ANY && c->x86_model != m->model)
75 continue;
76 if (m->steppings != X86_STEPPING_ANY &&
77 !(BIT(c->x86_stepping) & m->steppings))
78 continue;
79 if (m->feature != X86_FEATURE_ANY && !cpu_has(c, m->feature))
80 continue;
81 if (!x86_match_vendor_cpu_type(c, m))
82 continue;
83 return m;
84 }
85 return NULL;
86}
87EXPORT_SYMBOL(x86_match_cpu);
88
89bool x86_match_min_microcode_rev(const struct x86_cpu_id *table)
90{
91 const struct x86_cpu_id *res = x86_match_cpu(table);
92
93 if (!res || res->driver_data > boot_cpu_data.microcode)
94 return false;
95
96 return true;
97}
98EXPORT_SYMBOL_GPL(x86_match_min_microcode_rev);
99

source code of linux/arch/x86/kernel/cpu/match.c