1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
2 | /* |
3 | * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org> |
4 | */ |
5 | |
6 | #ifndef __LINUX_CPUFEATURE_H |
7 | #define __LINUX_CPUFEATURE_H |
8 | |
9 | #ifdef CONFIG_GENERIC_CPU_AUTOPROBE |
10 | |
11 | #include <linux/init.h> |
12 | #include <linux/mod_devicetable.h> |
13 | #include <asm/cpufeature.h> |
14 | |
15 | /* |
16 | * Macros imported from <asm/cpufeature.h>: |
17 | * - cpu_feature(x) ordinal value of feature called 'x' |
18 | * - cpu_have_feature(u32 n) whether feature #n is available |
19 | * - MAX_CPU_FEATURES upper bound for feature ordinal values |
20 | * Optional: |
21 | * - CPU_FEATURE_TYPEFMT format string fragment for printing the cpu type |
22 | * - CPU_FEATURE_TYPEVAL set of values matching the format string above |
23 | */ |
24 | |
25 | #ifndef CPU_FEATURE_TYPEFMT |
26 | #define CPU_FEATURE_TYPEFMT "%s" |
27 | #endif |
28 | |
29 | #ifndef CPU_FEATURE_TYPEVAL |
30 | #define CPU_FEATURE_TYPEVAL ELF_PLATFORM |
31 | #endif |
32 | |
33 | /* |
34 | * Use module_cpu_feature_match(feature, module_init_function) to |
35 | * declare that |
36 | * a) the module shall be probed upon discovery of CPU feature 'feature' |
37 | * (typically at boot time using udev) |
38 | * b) the module must not be loaded if CPU feature 'feature' is not present |
39 | * (not even by manual insmod). |
40 | * |
41 | * For a list of legal values for 'feature', please consult the file |
42 | * 'asm/cpufeature.h' of your favorite architecture. |
43 | */ |
44 | #define module_cpu_feature_match(x, __initfunc) \ |
45 | static struct cpu_feature const __maybe_unused cpu_feature_match_ ## x[] = \ |
46 | { { .feature = cpu_feature(x) }, { } }; \ |
47 | MODULE_DEVICE_TABLE(cpu, cpu_feature_match_ ## x); \ |
48 | \ |
49 | static int __init cpu_feature_match_ ## x ## _init(void) \ |
50 | { \ |
51 | if (!cpu_have_feature(cpu_feature(x))) \ |
52 | return -ENODEV; \ |
53 | return __initfunc(); \ |
54 | } \ |
55 | module_init(cpu_feature_match_ ## x ## _init) |
56 | |
57 | #endif |
58 | #endif |
59 | |