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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2013-07-09 14:18:12 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2013-08-20 12:12:26 +0100 |
| commit | 4cfb36136480c029a29dbf63a623506e6ed7282b (patch) | |
| tree | d812d9d1a8dd903be440257faf1a5e5c19cb70e1 | |
| parent | 178cd9ce377232518ec17ff2ecab2e80fa60784c (diff) | |
| download | lwn-4cfb36136480c029a29dbf63a623506e6ed7282b.tar.gz lwn-4cfb36136480c029a29dbf63a623506e6ed7282b.zip | |
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>
| -rw-r--r-- | arch/arm64/Kconfig | 3 | ||||
| -rw-r--r-- | arch/arm64/include/asm/neon.h | 14 | ||||
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 28 |
3 files changed, 45 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 9737e97f9f38..ae323a45c28c 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -96,6 +96,9 @@ 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 000000000000..b0cc58a97780 --- /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 e8b8357aedb4..1f2e4d5a5c0f 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(¤t->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(¤t->thread.fpsimd_state); +} +EXPORT_SYMBOL(kernel_neon_begin); + +void kernel_neon_end(void) +{ + if (current->mm) + fpsimd_load_state(¤t->thread.fpsimd_state); + + preempt_enable(); +} +EXPORT_SYMBOL(kernel_neon_end); + +#endif /* CONFIG_KERNEL_MODE_NEON */ + /* * FP/SIMD support code initialisation. */ |