1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org> 4 */ 5 6 #ifndef __ASM_SIMD_H 7 #define __ASM_SIMD_H 8 9 #include <linux/compiler.h> 10 #include <linux/irqflags.h> 11 #include <linux/percpu.h> 12 #include <linux/preempt.h> 13 #include <linux/types.h> 14 15 #ifdef CONFIG_KERNEL_MODE_NEON 16 17 /* 18 * may_use_simd - whether it is allowable at this time to issue SIMD 19 * instructions or access the SIMD register file 20 * 21 * Callers must not assume that the result remains true beyond the next 22 * preempt_enable() or return from softirq context. 23 */ 24 static __must_check inline bool may_use_simd(void) 25 { 26 /* 27 * We must make sure that the SVE has been initialized properly 28 * before using the SIMD in kernel. 29 */ 30 return !WARN_ON(!system_capabilities_finalized()) && 31 system_supports_fpsimd() && 32 !in_hardirq() && !irqs_disabled() && !in_nmi(); 33 } 34 35 #else /* ! CONFIG_KERNEL_MODE_NEON */ 36 37 static __must_check inline bool may_use_simd(void) { 38 return false; 39 } 40 41 #endif /* ! CONFIG_KERNEL_MODE_NEON */ 42 43 #endif 44