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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2013-07-09 14:18:12 +0100
committerMark Brown <broonie@linaro.org>2014-06-19 12:33:41 +0100
commitdf40a738827ebc244d552261fca865c98cd35e61 (patch)
tree1ee261715711f6d94ba7c8a7e1e3fa4b4eb95c12
parent8bb495e3f02401ee6f76d1b1d77f3ac9f079e376 (diff)
downloadlinux-df40a738827ebc244d552261fca865c98cd35e61.tar.gz
arm64: add support for kernel mode NEON
Add <asm/neon.h> containing kernel_neon_begin/kernel_neon_end function declarations and corresponding definitions in fpsimd.c These are needed to wrap uses of NEON in kernel mode. The names are identical to the ones used in arm/ so code using intrinsics or vectorized by GCC can be shared between arm and arm64. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> (cherry picked from commit 4cfb36136480c029a29dbf63a623506e6ed7282b) Signed-off-by: Mark Brown <broonie@linaro.org>
-rw-r--r--arch/arm64/Kconfig3
-rw-r--r--arch/arm64/include/asm/neon.h14
-rw-r--r--arch/arm64/kernel/fpsimd.c28
3 files changed, 45 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 56b3f6d447a..46ba6808435 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -95,6 +95,9 @@ config SWIOTLB
config IOMMU_HELPER
def_bool SWIOTLB
+config KERNEL_MODE_NEON
+ def_bool y
+
source "init/Kconfig"
source "kernel/Kconfig.freezer"
diff --git a/arch/arm64/include/asm/neon.h b/arch/arm64/include/asm/neon.h
new file mode 100644
index 00000000000..b0cc58a9778
--- /dev/null
+++ b/arch/arm64/include/asm/neon.h
@@ -0,0 +1,14 @@
+/*
+ * linux/arch/arm64/include/asm/neon.h
+ *
+ * Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define cpu_has_neon() (1)
+
+void kernel_neon_begin(void);
+void kernel_neon_end(void);
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index e8b8357aedb..1f2e4d5a5c0 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -21,6 +21,7 @@
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/signal.h>
+#include <linux/hardirq.h>
#include <asm/fpsimd.h>
#include <asm/cputype.h>
@@ -83,6 +84,33 @@ void fpsimd_flush_thread(void)
fpsimd_load_state(&current->thread.fpsimd_state);
}
+#ifdef CONFIG_KERNEL_MODE_NEON
+
+/*
+ * Kernel-side NEON support functions
+ */
+void kernel_neon_begin(void)
+{
+ /* Avoid using the NEON in interrupt context */
+ BUG_ON(in_interrupt());
+ preempt_disable();
+
+ if (current->mm)
+ fpsimd_save_state(&current->thread.fpsimd_state);
+}
+EXPORT_SYMBOL(kernel_neon_begin);
+
+void kernel_neon_end(void)
+{
+ if (current->mm)
+ fpsimd_load_state(&current->thread.fpsimd_state);
+
+ preempt_enable();
+}
+EXPORT_SYMBOL(kernel_neon_end);
+
+#endif /* CONFIG_KERNEL_MODE_NEON */
+
/*
* FP/SIMD support code initialisation.
*/