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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2014-03-04 01:10:04 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2014-03-14 18:01:36 +0000 |
| commit | 3be1a5c4f75989cf457f13f38ff0913dff6d4996 (patch) | |
| tree | 312f3bbfa0c6e783ea01078a701ce95667aabcbf /arch/arm64 | |
| parent | 7184659bed3090248e382d98a49a3c1bcfe11174 (diff) | |
| download | linux-3be1a5c4f75989cf457f13f38ff0913dff6d4996.tar.bz2 | |
arm64: enable generic CPU feature modalias matching for this architecture
This enables support for the generic CPU feature modalias implementation that
wires up optional CPU features to udev based module autoprobing.
A file <asm/cpufeature.h> is provided that maps CPU feature numbers to
elf_hwcap bits, which is the standard way on arm64 to advertise optional CPU
features both internally and to user space.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[catalin.marinas@arm.com: removed unnecessary "!!"]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 29 |
2 files changed, 30 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 507ab6e53522..8cabe36e285c 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -16,6 +16,7 @@ config ARM64 select DCACHE_WORD_ACCESS select GENERIC_CLOCKEVENTS select GENERIC_CLOCKEVENTS_BROADCAST if SMP + select GENERIC_CPU_AUTOPROBE select GENERIC_IOMAP select GENERIC_IRQ_PROBE select GENERIC_IRQ_SHOW diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h new file mode 100644 index 000000000000..cd4ac0516488 --- /dev/null +++ b/arch/arm64/include/asm/cpufeature.h @@ -0,0 +1,29 @@ +/* + * 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 __ASM_CPUFEATURE_H +#define __ASM_CPUFEATURE_H + +#include <asm/hwcap.h> + +/* + * In the arm64 world (as in the ARM world), elf_hwcap is used both internally + * in the kernel and for user space to keep track of which optional features + * are supported by the current system. So let's map feature 'x' to HWCAP_x. + * Note that HWCAP_x constants are bit fields so we need to take the log. + */ + +#define MAX_CPU_FEATURES (8 * sizeof(elf_hwcap)) +#define cpu_feature(x) ilog2(HWCAP_ ## x) + +static inline bool cpu_have_feature(unsigned int num) +{ + return elf_hwcap & (1UL << num); +} + +#endif |