From 7d11965ddb9b9b1e0a5d13c58345ada1ccbc663b Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Thu, 16 May 2013 17:20:32 +0200 Subject: lib/raid6: add ARM-NEON accelerated syndrome calculation Rebased/reworked a patch contributed by Rob Herring that uses NEON intrinsics to perform the RAID-6 syndrome calculations. It uses the existing unroll.awk code to generate several unrolled versions of which the best performing one is selected at boot time. Signed-off-by: Ard Biesheuvel Acked-by: Nicolas Pitre Cc: hpa@linux.intel.com --- lib/raid6/neon.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 lib/raid6/neon.c (limited to 'lib/raid6/neon.c') diff --git a/lib/raid6/neon.c b/lib/raid6/neon.c new file mode 100644 index 000000000000..36ad4705df1a --- /dev/null +++ b/lib/raid6/neon.c @@ -0,0 +1,58 @@ +/* + * linux/lib/raid6/neon.c - RAID6 syndrome calculation using ARM NEON intrinsics + * + * Copyright (C) 2013 Linaro Ltd + * + * 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. + */ + +#include + +#ifdef __KERNEL__ +#include +#else +#define kernel_neon_begin() +#define kernel_neon_end() +#define cpu_has_neon() (1) +#endif + +/* + * There are 2 reasons these wrappers are kept in a separate compilation unit + * from the actual implementations in neonN.c (generated from neon.uc by + * unroll.awk): + * - the actual implementations use NEON intrinsics, and the GCC support header + * (arm_neon.h) is not fully compatible (type wise) with the kernel; + * - the neonN.c files are compiled with -mfpu=neon and optimization enabled, + * and we have to make sure that we never use *any* NEON/VFP instructions + * outside a kernel_neon_begin()/kernel_neon_end() pair. + */ + +#define RAID6_NEON_WRAPPER(_n) \ + static void raid6_neon ## _n ## _gen_syndrome(int disks, \ + size_t bytes, void **ptrs) \ + { \ + void raid6_neon ## _n ## _gen_syndrome_real(int, \ + unsigned long, void**); \ + kernel_neon_begin(); \ + raid6_neon ## _n ## _gen_syndrome_real(disks, \ + (unsigned long)bytes, ptrs); \ + kernel_neon_end(); \ + } \ + struct raid6_calls const raid6_neonx ## _n = { \ + raid6_neon ## _n ## _gen_syndrome, \ + raid6_have_neon, \ + "neonx" #_n, \ + 0 \ + } + +static int raid6_have_neon(void) +{ + return cpu_has_neon(); +} + +RAID6_NEON_WRAPPER(1); +RAID6_NEON_WRAPPER(2); +RAID6_NEON_WRAPPER(4); +RAID6_NEON_WRAPPER(8); -- cgit