lib/raid6/recov_neon.c

   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
  21 static int raid6_has_neon(void)
  22 {
  23         return cpu_has_neon();
  24 }
  25
  26 void __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
  30 void __raid6_datap_recov_neon(int bytes, uint8_t *p, uint8_t *q, uint8_t *dq,
  31                               const uint8_t *qmul);
  32
  33 static 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
  73 static 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
 104 const 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 };