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) \ 47static struct cpu_feature const cpu_feature_match_ ## x[] = \ 48 { { .feature = cpu_feature(x) }, { } }; \ 49MODULE_DEVICE_TABLE(cpu, cpu_feature_match_ ## x); \ 50 \ 51static int cpu_feature_match_ ## x ## _init(void) \ 52{ \ 53 if (!cpu_have_feature(cpu_feature(x))) \ 54 return -ENODEV; \ 55 return __init(); \ 56} \ 57module_init(cpu_feature_match_ ## x ## _init) 58 59#endif 60#endif 61