[PATCH v4 05/21] ARM/simd: Add scoped guard API for kernel mode SIMD

[Ard Biesheuvel <ardb+git@google.com>]

From: Ard Biesheuvel <ardb@kernel.org>

Implement the ksimd scoped guard API so that it can be used by code that
supports both ARM and arm64.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/arm/include/asm/simd.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/include/asm/simd.h b/arch/arm/include/asm/simd.h
index be08a8da046f..8549fa8b7253 100644
--- a/arch/arm/include/asm/simd.h
+++ b/arch/arm/include/asm/simd.h
@@ -2,14 +2,21 @@
 #ifndef _ASM_SIMD_H
 #define _ASM_SIMD_H
 
+#include <linux/cleanup.h>
 #include <linux/compiler_attributes.h>
 #include <linux/preempt.h>
 #include <linux/types.h>
 
+#include <asm/neon.h>
+
 static __must_check inline bool may_use_simd(void)
 {
 	return IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && !in_hardirq()
 	       && !irqs_disabled();
 }
 
+DEFINE_LOCK_GUARD_0(ksimd, kernel_neon_begin(), kernel_neon_end())
+
+#define scoped_ksimd()	scoped_guard(ksimd)
+
 #endif	/* _ASM_SIMD_H */
-- 
2.51.1.930.gacf6e81ea2-goog