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