LXR linux/lib/raid6/recov

   1/*
   2 * Copyright (C) 2012 Intel Corporation
   3 * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org>
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License
   7 * as published by the Free Software Foundation; version 2
   8 * of the License.
   9 */
  10
  11#include <linux/raid/pq.h>
  12
  13#ifdef __KERNEL__
  14#include <asm/neon.h>
  15#else
  16#define kernel_neon_begin()
  17#define kernel_neon_end()
  18#define cpu_has_neon()          (1)
  19#endif
  20
  21static int raid6_has_neon(void)
  22{
  23        return cpu_has_neon();
  24}
  25
  26void __raid6_2data_recov_neon(int bytes, uint8_t *p, uint8_t *q, uint8_t *dp,
  27                              uint8_t *dq, const uint8_t *pbmul,
  28                              const uint8_t *qmul);
  29
  30void __raid6_datap_recov_neon(int bytes, uint8_t *p, uint8_t *q, uint8_t *dq,
  31                              const uint8_t *qmul);
  32
  33static void raid6_2data_recov_neon(int disks, size_t bytes, int faila,
  34                int failb, void **ptrs)
  35{
  36        u8 *p, *q, *dp, *dq;
  37        const u8 *pbmul;        /* P multiplier table for B data */
  38        const u8 *qmul;         /* Q multiplier table (for both) */
  39
  40        p = (u8 *)ptrs[disks - 2];
  41        q = (u8 *)ptrs[disks - 1];
  42
  43        /*
  44         * Compute syndrome with zero for the missing data pages
  45         * Use the dead data pages as temporary storage for
  46         * delta p and delta q
  47         */
  48        dp = (u8 *)ptrs[faila];
  49        ptrs[faila] = (void *)raid6_empty_zero_page;
  50        ptrs[disks - 2] = dp;
  51        dq = (u8 *)ptrs[failb];
  52        ptrs[failb] = (void *)raid6_empty_zero_page;
  53        ptrs[disks - 1] = dq;
  54
  55        raid6_call.gen_syndrome(disks, bytes, ptrs);
  56
  57        /* Restore pointer table */
  58        ptrs[faila]     = dp;
  59        ptrs[failb]     = dq;
  60        ptrs[disks - 2] = p;
  61        ptrs[disks - 1] = q;
  62
  63        /* Now, pick the proper data tables */
  64        pbmul = raid6_vgfmul[raid6_gfexi[failb-faila]];
  65        qmul  = raid6_vgfmul[raid6_gfinv[raid6_gfexp[faila] ^
  66                                         raid6_gfexp[failb]]];
  67
  68        kernel_neon_begin();
  69        __raid6_2data_recov_neon(bytes, p, q, dp, dq, pbmul, qmul);
  70        kernel_neon_end();
  71}
  72
  73static void raid6_datap_recov_neon(int disks, size_t bytes, int faila,
  74                void **ptrs)
  75{
  76        u8 *p, *q, *dq;
  77        const u8 *qmul;         /* Q multiplier table */
  78
  79        p = (u8 *)ptrs[disks - 2];
  80        q = (u8 *)ptrs[disks - 1];
  81
  82        /*
  83         * Compute syndrome with zero for the missing data page
  84         * Use the dead data page as temporary storage for delta q
  85         */
  86        dq = (u8 *)ptrs[faila];
  87        ptrs[faila] = (void *)raid6_empty_zero_page;
  88        ptrs[disks - 1] = dq;
  89
  90        raid6_call.gen_syndrome(disks, bytes, ptrs);
  91
  92        /* Restore pointer table */
  93        ptrs[faila]     = dq;
  94        ptrs[disks - 1] = q;
  95
  96        /* Now, pick the proper data tables */
  97        qmul = raid6_vgfmul[raid6_gfinv[raid6_gfexp[faila]]];
  98
  99        kernel_neon_begin();
 100        __raid6_datap_recov_neon(bytes, p, q, dq, qmul);
 101        kernel_neon_end();
 102}
 103
 104const struct raid6_recov_calls raid6_recov_neon = {
 105        .data2          = raid6_2data_recov_neon,
 106        .datap          = raid6_datap_recov_neon,
 107        .valid          = raid6_has_neon,
 108        .name           = "neon",
 109        .priority       = 10,
 110};
 111