linux/linux-5.18.11/arch/arm/include/asm/neon.h

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2024-03-22 18:12:32 +00:00
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/include/asm/neon.h
*
* Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
*/
#include <asm/hwcap.h>
#define cpu_has_neon() (!!(elf_hwcap & HWCAP_NEON))
#ifdef __ARM_NEON__
/*
* If you are affected by the BUILD_BUG below, it probably means that you are
* using NEON code /and/ calling the kernel_neon_begin() function from the same
* compilation unit. To prevent issues that may arise from GCC reordering or
* generating(1) NEON instructions outside of these begin/end functions, the
* only supported way of using NEON code in the kernel is by isolating it in a
* separate compilation unit, and calling it from another unit from inside a
* kernel_neon_begin/kernel_neon_end pair.
*
* (1) Current GCC (4.7) might generate NEON instructions at O3 level if
* -mpfu=neon is set.
*/
#define kernel_neon_begin() \
BUILD_BUG_ON_MSG(1, "kernel_neon_begin() called from NEON code")
#else
void kernel_neon_begin(void);
#endif
void kernel_neon_end(void);