From 6ec4e2514decd6fb4782a9364fa71d6244d05af4 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Thu, 13 Jul 2017 18:16:01 +0100 Subject: md/raid6: implement recovery using ARM NEON intrinsics Provide a NEON accelerated implementation of the recovery algorithm, which supersedes the default byte-by-byte one. Signed-off-by: Ard Biesheuvel Signed-off-by: Catalin Marinas --- lib/raid6/recov_neon.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 lib/raid6/recov_neon.c (limited to 'lib/raid6/recov_neon.c') diff --git a/lib/raid6/recov_neon.c b/lib/raid6/recov_neon.c new file mode 100644 index 000000000000..eeb5c4065b92 --- /dev/null +++ b/lib/raid6/recov_neon.c @@ -0,0 +1,110 @@ +/* + * Copyright (C) 2012 Intel Corporation + * Copyright (C) 2017 Linaro Ltd. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ + +#include + +#ifdef __KERNEL__ +#include +#else +#define kernel_neon_begin() +#define kernel_neon_end() +#define cpu_has_neon() (1) +#endif + +static int raid6_has_neon(void) +{ + return cpu_has_neon(); +} + +void __raid6_2data_recov_neon(int bytes, uint8_t *p, uint8_t *q, uint8_t *dp, + uint8_t *dq, const uint8_t *pbmul, + const uint8_t *qmul); + +void __raid6_datap_recov_neon(int bytes, uint8_t *p, uint8_t *q, uint8_t *dq, + const uint8_t *qmul); + +static void raid6_2data_recov_neon(int disks, size_t bytes, int faila, + int failb, void **ptrs) +{ + u8 *p, *q, *dp, *dq; + const u8 *pbmul; /* P multiplier table for B data */ + const u8 *qmul; /* Q multiplier table (for both) */ + + p = (u8 *)ptrs[disks - 2]; + q = (u8 *)ptrs[disks - 1]; + + /* + * Compute syndrome with zero for the missing data pages + * Use the dead data pages as temporary storage for + * delta p and delta q + */ + dp = (u8 *)ptrs[faila]; + ptrs[faila] = (void *)raid6_empty_zero_page; + ptrs[disks - 2] = dp; + dq = (u8 *)ptrs[failb]; + ptrs[failb] = (void *)raid6_empty_zero_page; + ptrs[disks - 1] = dq; + + raid6_call.gen_syndrome(disks, bytes, ptrs); + + /* Restore pointer table */ + ptrs[faila] = dp; + ptrs[failb] = dq; + ptrs[disks - 2] = p; + ptrs[disks - 1] = q; + + /* Now, pick the proper data tables */ + pbmul = raid6_vgfmul[raid6_gfexi[failb-faila]]; + qmul = raid6_vgfmul[raid6_gfinv[raid6_gfexp[faila] ^ + raid6_gfexp[failb]]]; + + kernel_neon_begin(); + __raid6_2data_recov_neon(bytes, p, q, dp, dq, pbmul, qmul); + kernel_neon_end(); +} + +static void raid6_datap_recov_neon(int disks, size_t bytes, int faila, + void **ptrs) +{ + u8 *p, *q, *dq; + const u8 *qmul; /* Q multiplier table */ + + p = (u8 *)ptrs[disks - 2]; + q = (u8 *)ptrs[disks - 1]; + + /* + * Compute syndrome with zero for the missing data page + * Use the dead data page as temporary storage for delta q + */ + dq = (u8 *)ptrs[faila]; + ptrs[faila] = (void *)raid6_empty_zero_page; + ptrs[disks - 1] = dq; + + raid6_call.gen_syndrome(disks, bytes, ptrs); + + /* Restore pointer table */ + ptrs[faila] = dq; + ptrs[disks - 1] = q; + + /* Now, pick the proper data tables */ + qmul = raid6_vgfmul[raid6_gfinv[raid6_gfexp[faila]]]; + + kernel_neon_begin(); + __raid6_datap_recov_neon(bytes, p, q, dq, qmul); + kernel_neon_end(); +} + +const struct raid6_recov_calls raid6_recov_neon = { + .data2 = raid6_2data_recov_neon, + .datap = raid6_datap_recov_neon, + .valid = raid6_has_neon, + .name = "neon", + .priority = 10, +}; -- cgit v1.2.3