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/mod_devicetable.h> 15 #include <asm/cpufeature.h> 16 17 /* 18 * Macros imported from <asm/cpufeature.h>: 19 * - cpu_feature(x) ordinal value of feature called 'x' 20 * - cpu_have_feature(u32 n) whether feature #n is available 21 * - MAX_CPU_FEATURES upper bound for feature ordinal values 22 * Optional: 23 * - CPU_FEATURE_TYPEFMT format string fragment for printing the cpu type 24 * - CPU_FEATURE_TYPEVAL set of values matching the format string above 25 */ 26 27 #ifndef CPU_FEATURE_TYPEFMT 28 #define CPU_FEATURE_TYPEFMT "%s" 29 #endif 30 31 #ifndef CPU_FEATURE_TYPEVAL 32 #define CPU_FEATURE_TYPEVAL ELF_PLATFORM 33 #endif 34 35 /* 36 * Use module_cpu_feature_match(feature, module_init_function) to 37 * declare that 38 * a) the module shall be probed upon discovery of CPU feature 'feature' 39 * (typically at boot time using udev) 40 * b) the module must not be loaded if CPU feature 'feature' is not present 41 * (not even by manual insmod). 42 * 43 * For a list of legal values for 'feature', please consult the file 44 * 'asm/cpufeature.h' of your favorite architecture. 45 */ 46 #define module_cpu_feature_match(x, __init) \ 47 static struct cpu_feature const cpu_feature_match_ ## x[] = \ 48 { { .feature = cpu_feature(x) }, { } }; \ 49 MODULE_DEVICE_TABLE(cpu, cpu_feature_match_ ## x); \ 50 \ 51 static int cpu_feature_match_ ## x ## _init(void) \ 52 { \ 53 if (!cpu_have_feature(cpu_feature(x))) \ 54 return -ENODEV; \ 55 return __init(); \ 56 } \ 57 module_init(cpu_feature_match_ ## x ## _init) 58 59 #endif 60 #endif 61