1d2912cb1SThomas Gleixner /* SPDX-License-Identifier: GPL-2.0-only */ 273c132c1SArd Biesheuvel /* 373c132c1SArd Biesheuvel * linux/arch/arm/include/asm/neon.h 473c132c1SArd Biesheuvel * 573c132c1SArd Biesheuvel * Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org> 673c132c1SArd Biesheuvel */ 773c132c1SArd Biesheuvel 873c132c1SArd Biesheuvel #include <asm/hwcap.h> 973c132c1SArd Biesheuvel 1073c132c1SArd Biesheuvel #define cpu_has_neon() (!!(elf_hwcap & HWCAP_NEON)) 1173c132c1SArd Biesheuvel 1273c132c1SArd Biesheuvel #ifdef __ARM_NEON__ 1373c132c1SArd Biesheuvel 1473c132c1SArd Biesheuvel /* 1573c132c1SArd Biesheuvel * If you are affected by the BUILD_BUG below, it probably means that you are 1673c132c1SArd Biesheuvel * using NEON code /and/ calling the kernel_neon_begin() function from the same 1773c132c1SArd Biesheuvel * compilation unit. To prevent issues that may arise from GCC reordering or 1873c132c1SArd Biesheuvel * generating(1) NEON instructions outside of these begin/end functions, the 1973c132c1SArd Biesheuvel * only supported way of using NEON code in the kernel is by isolating it in a 2073c132c1SArd Biesheuvel * separate compilation unit, and calling it from another unit from inside a 2173c132c1SArd Biesheuvel * kernel_neon_begin/kernel_neon_end pair. 2273c132c1SArd Biesheuvel * 2373c132c1SArd Biesheuvel * (1) Current GCC (4.7) might generate NEON instructions at O3 level if 2473c132c1SArd Biesheuvel * -mpfu=neon is set. 2573c132c1SArd Biesheuvel */ 2673c132c1SArd Biesheuvel 2773c132c1SArd Biesheuvel #define kernel_neon_begin() \ 2873c132c1SArd Biesheuvel BUILD_BUG_ON_MSG(1, "kernel_neon_begin() called from NEON code") 2973c132c1SArd Biesheuvel 3073c132c1SArd Biesheuvel #else 3173c132c1SArd Biesheuvel void kernel_neon_begin(void); 3273c132c1SArd Biesheuvel #endif 3373c132c1SArd Biesheuvel void kernel_neon_end(void); 34