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) \ 48static struct cpu_feature const cpu_feature_match_ ## x[] = \ 49 { { .feature = cpu_feature(x) }, { } }; \ 50MODULE_DEVICE_TABLE(cpu, cpu_feature_match_ ## x); \ 51 \ 52static int __init cpu_feature_match_ ## x ## _init(void) \ 53{ \ 54 if (!cpu_have_feature(cpu_feature(x))) \ 55 return -ENODEV; \ 56 return __initfunc(); \ 57} \ 58module_init(cpu_feature_match_ ## x ## _init) 59 60#endif 61#endif 62