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
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