1/* SPDX-License-Identifier: GPL-2.0-only */
 2/*
 3 * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org>
 
 
 
 
 4 */
 5
 6#ifndef __ASM_CPUFEATURE_H
 7#define __ASM_CPUFEATURE_H
 8
 9#include <linux/log2.h>
10#include <asm/hwcap.h>
11
12/*
13 * Due to the fact that ELF_HWCAP is a 32-bit type on ARM, and given the number
14 * of optional CPU features it defines, ARM's CPU hardware capability bits have
15 * been distributed over separate elf_hwcap and elf_hwcap2 variables, each of
16 * which covers a subset of the available CPU features.
17 *
18 * Currently, only a few of those are suitable for automatic module loading
19 * (which is the primary use case of this facility) and those happen to be all
20 * covered by HWCAP2. So let's only cover those via the cpu_feature()
21 * convenience macro for now (which is used by module_cpu_feature_match()).
22 * However, all capabilities are exposed via the modalias, and can be matched
23 * using an explicit MODULE_DEVICE_TABLE() that uses __hwcap_feature() directly.
24 */
25#define MAX_CPU_FEATURES	64
26#define __hwcap_feature(x)	ilog2(HWCAP_ ## x)
27#define __hwcap2_feature(x)	(32 + ilog2(HWCAP2_ ## x))
28#define cpu_feature(x)		__hwcap2_feature(x)
29
30static inline bool cpu_have_feature(unsigned int num)
31{
32	return num < 32 ? elf_hwcap & BIT(num) : elf_hwcap2 & BIT(num - 32);
33}
34
35#endif

 
 1/*
 2 * Copyright (C) 2017 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 __ASM_CPUFEATURE_H
10#define __ASM_CPUFEATURE_H
11
12#include <linux/log2.h>
13#include <asm/hwcap.h>
14
15/*
16 * Due to the fact that ELF_HWCAP is a 32-bit type on ARM, and given the number
17 * of optional CPU features it defines, ARM's CPU hardware capability bits have
18 * been distributed over separate elf_hwcap and elf_hwcap2 variables, each of
19 * which covers a subset of the available CPU features.
20 *
21 * Currently, only a few of those are suitable for automatic module loading
22 * (which is the primary use case of this facility) and those happen to be all
23 * covered by HWCAP2. So let's only cover those via the cpu_feature()
24 * convenience macro for now (which is used by module_cpu_feature_match()).
25 * However, all capabilities are exposed via the modalias, and can be matched
26 * using an explicit MODULE_DEVICE_TABLE() that uses __hwcap_feature() directly.
27 */
28#define MAX_CPU_FEATURES	64
29#define __hwcap_feature(x)	ilog2(HWCAP_ ## x)
30#define __hwcap2_feature(x)	(32 + ilog2(HWCAP2_ ## x))
31#define cpu_feature(x)		__hwcap2_feature(x)
32
33static inline bool cpu_have_feature(unsigned int num)
34{
35	return num < 32 ? elf_hwcap & BIT(num) : elf_hwcap2 & BIT(num - 32);
36}
37
38#endif