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Diffstat (limited to 'kernel/include/linux/cpufeature.h')
| -rw-r--r-- | kernel/include/linux/cpufeature.h | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/kernel/include/linux/cpufeature.h b/kernel/include/linux/cpufeature.h new file mode 100644 index 000000000..c4d4eb8ac --- /dev/null +++ b/kernel/include/linux/cpufeature.h @@ -0,0 +1,60 @@ +/* + * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef __LINUX_CPUFEATURE_H +#define __LINUX_CPUFEATURE_H + +#ifdef CONFIG_GENERIC_CPU_AUTOPROBE + +#include <linux/mod_devicetable.h> +#include <asm/cpufeature.h> + +/* + * Macros imported from <asm/cpufeature.h>: + * - cpu_feature(x) ordinal value of feature called 'x' + * - cpu_have_feature(u32 n) whether feature #n is available + * - MAX_CPU_FEATURES upper bound for feature ordinal values + * Optional: + * - CPU_FEATURE_TYPEFMT format string fragment for printing the cpu type + * - CPU_FEATURE_TYPEVAL set of values matching the format string above + */ + +#ifndef CPU_FEATURE_TYPEFMT +#define CPU_FEATURE_TYPEFMT "%s" +#endif + +#ifndef CPU_FEATURE_TYPEVAL +#define CPU_FEATURE_TYPEVAL ELF_PLATFORM +#endif + +/* + * Use module_cpu_feature_match(feature, module_init_function) to + * declare that + * a) the module shall be probed upon discovery of CPU feature 'feature' + * (typically at boot time using udev) + * b) the module must not be loaded if CPU feature 'feature' is not present + * (not even by manual insmod). + * + * For a list of legal values for 'feature', please consult the file + * 'asm/cpufeature.h' of your favorite architecture. + */ +#define module_cpu_feature_match(x, __init) \ +static struct cpu_feature const cpu_feature_match_ ## x[] = \ + { { .feature = cpu_feature(x) }, { } }; \ +MODULE_DEVICE_TABLE(cpu, cpu_feature_match_ ## x); \ + \ +static int cpu_feature_match_ ## x ## _init(void) \ +{ \ + if (!cpu_have_feature(cpu_feature(x))) \ + return -ENODEV; \ + return __init(); \ +} \ +module_init(cpu_feature_match_ ## x ## _init) + +#endif +#endif |