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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>
30 lines
847 B
C
30 lines
847 B
C
/*
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* Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef __ASM_CPUFEATURE_H
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#define __ASM_CPUFEATURE_H
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#include <asm/hwcap.h>
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/*
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* In the arm64 world (as in the ARM world), elf_hwcap is used both internally
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* in the kernel and for user space to keep track of which optional features
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* are supported by the current system. So let's map feature 'x' to HWCAP_x.
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* Note that HWCAP_x constants are bit fields so we need to take the log.
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*/
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#define MAX_CPU_FEATURES (8 * sizeof(elf_hwcap))
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#define cpu_feature(x) ilog2(HWCAP_ ## x)
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static inline bool cpu_have_feature(unsigned int num)
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{
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return elf_hwcap & (1UL << num);
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}
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#endif
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