Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
[firefly-linux-kernel-4.4.55.git] / include / linux / cpufeature.h
1 /*
2  * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8
9 #ifndef __LINUX_CPUFEATURE_H
10 #define __LINUX_CPUFEATURE_H
11
12 #ifdef CONFIG_GENERIC_CPU_AUTOPROBE
13
14 #include <linux/init.h>
15 #include <linux/mod_devicetable.h>
16 #include <asm/cpufeature.h>
17
18 /*
19  * Macros imported from <asm/cpufeature.h>:
20  * - cpu_feature(x)             ordinal value of feature called 'x'
21  * - cpu_have_feature(u32 n)    whether feature #n is available
22  * - MAX_CPU_FEATURES           upper bound for feature ordinal values
23  * Optional:
24  * - CPU_FEATURE_TYPEFMT        format string fragment for printing the cpu type
25  * - CPU_FEATURE_TYPEVAL        set of values matching the format string above
26  */
27
28 #ifndef CPU_FEATURE_TYPEFMT
29 #define CPU_FEATURE_TYPEFMT     "%s"
30 #endif
31
32 #ifndef CPU_FEATURE_TYPEVAL
33 #define CPU_FEATURE_TYPEVAL     ELF_PLATFORM
34 #endif
35
36 /*
37  * Use module_cpu_feature_match(feature, module_init_function) to
38  * declare that
39  * a) the module shall be probed upon discovery of CPU feature 'feature'
40  *    (typically at boot time using udev)
41  * b) the module must not be loaded if CPU feature 'feature' is not present
42  *    (not even by manual insmod).
43  *
44  * For a list of legal values for 'feature', please consult the file
45  * 'asm/cpufeature.h' of your favorite architecture.
46  */
47 #define module_cpu_feature_match(x, __initfunc)                 \
48 static struct cpu_feature const cpu_feature_match_ ## x[] =     \
49         { { .feature = cpu_feature(x) }, { } };                 \
50 MODULE_DEVICE_TABLE(cpu, cpu_feature_match_ ## x);              \
51                                                                 \
52 static int __init cpu_feature_match_ ## x ## _init(void)        \
53 {                                                               \
54         if (!cpu_have_feature(cpu_feature(x)))                  \
55                 return -ENODEV;                                 \
56         return __initfunc();                                    \
57 }                                                               \
58 module_init(cpu_feature_match_ ## x ## _init)
59
60 #endif
61 #endif