arch/sparc/lib/blockops.S

   1 /* $Id: blockops.S,v 1.8 1998/01/30 10:58:44 jj Exp $
   2  * blockops.S: Common block zero optimized routines.
   3  *
   4  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
   5  */
   6
   7 #include <asm/page.h>
   8
   9         /* Zero out 64 bytes of memory at (buf + offset).
  10          * Assumes %g1 contains zero.
  11          */
  12 #define BLAST_BLOCK(buf, offset) \
  13         std     %g0, [buf + offset + 0x38]; \
  14         std     %g0, [buf + offset + 0x30]; \
  15         std     %g0, [buf + offset + 0x28]; \
  16         std     %g0, [buf + offset + 0x20]; \
  17         std     %g0, [buf + offset + 0x18]; \
  18         std     %g0, [buf + offset + 0x10]; \
  19         std     %g0, [buf + offset + 0x08]; \
  20         std     %g0, [buf + offset + 0x00];
  21
  22         /* Copy 32 bytes of memory at (src + offset) to
  23          * (dst + offset).
  24          */
  25 #define MIRROR_BLOCK(dst, src, offset, t0, t1, t2, t3, t4, t5, t6, t7) \
  26         ldd     [src + offset + 0x18], t0; \
  27         ldd     [src + offset + 0x10], t2; \
  28         ldd     [src + offset + 0x08], t4; \
  29         ldd     [src + offset + 0x00], t6; \
  30         std     t0, [dst + offset + 0x18]; \
  31         std     t2, [dst + offset + 0x10]; \
  32         std     t4, [dst + offset + 0x08]; \
  33         std     t6, [dst + offset + 0x00];
  34
  35         /* Profiling evidence indicates that memset() is
  36          * commonly called for blocks of size PAGE_SIZE,
  37          * and (2 * PAGE_SIZE) (for kernel stacks)
  38          * and with a second arg of zero.  We assume in
  39          * all of these cases that the buffer is aligned
  40          * on at least an 8 byte boundary.
  41          *
  42          * Therefore we special case them to make them
  43          * as fast as possible.
  44          */
  45
  46         .text
  47         .align  4
  48         .globl  bzero_1page, __copy_1page
  49
  50 bzero_1page:
  51 /* NOTE: If you change the number of insns of this routine, please check
  52  * arch/sparc/mm/hypersparc.S */
  53         /* %o0 = buf */
  54         or      %g0, %g0, %g1
  55         or      %o0, %g0, %o1
  56         or      %g0, (PAGE_SIZE >> 8), %g2
  57 1:
  58         BLAST_BLOCK(%o0, 0x00)
  59         BLAST_BLOCK(%o0, 0x40)
  60         BLAST_BLOCK(%o0, 0x80)
  61         BLAST_BLOCK(%o0, 0xc0)
  62         subcc   %g2, 1, %g2
  63         bne     1b
  64          add    %o0, 0x100, %o0
  65
  66         retl
  67          nop
  68
  69 __copy_1page:
  70 /* NOTE: If you change the number of insns of this routine, please check
  71  * arch/sparc/mm/hypersparc.S */
  72         /* %o0 = dst, %o1 = src */
  73         or      %g0, (PAGE_SIZE >> 8), %g1
  74 1:
  75         MIRROR_BLOCK(%o0, %o1, 0x00, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  76         MIRROR_BLOCK(%o0, %o1, 0x20, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  77         MIRROR_BLOCK(%o0, %o1, 0x40, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  78         MIRROR_BLOCK(%o0, %o1, 0x60, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  79         MIRROR_BLOCK(%o0, %o1, 0x80, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  80         MIRROR_BLOCK(%o0, %o1, 0xa0, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  81         MIRROR_BLOCK(%o0, %o1, 0xc0, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  82         MIRROR_BLOCK(%o0, %o1, 0xe0, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  83         subcc   %g1, 1, %g1
  84         add     %o0, 0x100, %o0
  85         bne     1b
  86          add    %o1, 0x100, %o1
  87
  88         retl
  89          nop