lib/raid6/tilegx.uc

   1 /* -*- linux-c -*- ------------------------------------------------------- *
   2  *
   3  *   Copyright 2002 H. Peter Anvin - All Rights Reserved
   4  *   Copyright 2012 Tilera Corporation - All Rights Reserved
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
   9  *   Boston MA 02111-1307, USA; either version 2 of the License, or
  10  *   (at your option) any later version; incorporated herein by reference.
  11  *
  12  * ----------------------------------------------------------------------- */
  13
  14 /*
  15  * tilegx$#.c
  16  *
  17  * $#-way unrolled TILE-Gx SIMD for RAID-6 math.
  18  *
  19  * This file is postprocessed using unroll.awk.
  20  *
  21  */
  22
  23 #include <linux/raid/pq.h>
  24
  25 /* Create 8 byte copies of constant byte */
  26 # define NBYTES(x) (__insn_v1addi(0, x))
  27 # define NSIZE  8
  28
  29 /*
  30  * The SHLBYTE() operation shifts each byte left by 1, *not*
  31  * rolling over into the next byte
  32  */
  33 static inline __attribute_const__ u64 SHLBYTE(u64 v)
  34 {
  35         /* Vector One Byte Shift Left Immediate. */
  36         return __insn_v1shli(v, 1);
  37 }
  38
  39 /*
  40  * The MASK() operation returns 0xFF in any byte for which the high
  41  * bit is 1, 0x00 for any byte for which the high bit is 0.
  42  */
  43 static inline __attribute_const__ u64 MASK(u64 v)
  44 {
  45         /* Vector One Byte Shift Right Signed Immediate. */
  46         return __insn_v1shrsi(v, 7);
  47 }
  48
  49
  50 void raid6_tilegx$#_gen_syndrome(int disks, size_t bytes, void **ptrs)
  51 {
  52         u8 **dptr = (u8 **)ptrs;
  53         u64 *p, *q;
  54         int d, z, z0;
  55
  56         u64 wd$$, wq$$, wp$$, w1$$, w2$$;
  57         u64 x1d = NBYTES(0x1d);
  58         u64 * z0ptr;
  59
  60         z0 = disks - 3;                 /* Highest data disk */
  61         p = (u64 *)dptr[z0+1];  /* XOR parity */
  62         q = (u64 *)dptr[z0+2];  /* RS syndrome */
  63
  64         z0ptr = (u64 *)&dptr[z0][0];
  65         for ( d = 0 ; d < bytes ; d += NSIZE*$# ) {
  66                 wq$$ = wp$$ = *z0ptr++;
  67                 for ( z = z0-1 ; z >= 0 ; z-- ) {
  68                         wd$$ = *(u64 *)&dptr[z][d+$$*NSIZE];
  69                         wp$$ = wp$$ ^ wd$$;
  70                         w2$$ = MASK(wq$$);
  71                         w1$$ = SHLBYTE(wq$$);
  72                         w2$$ = w2$$ & x1d;
  73                         w1$$ = w1$$ ^ w2$$;
  74                         wq$$ = w1$$ ^ wd$$;
  75                 }
  76                 *p++ = wp$$;
  77                 *q++ = wq$$;
  78         }
  79 }
  80
  81 const struct raid6_calls raid6_tilegx$# = {
  82         raid6_tilegx$#_gen_syndrome,
  83         NULL,                   /* XOR not yet implemented */
  84         NULL,
  85         "tilegx$#",
  86         0
  87 };