root/arch/sparc/lib/blockops.S

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * blockops.S: Common block zero optimized routines.
   4  *
   5  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
   6  */
   7 
   8 #include <linux/linkage.h>
   9 #include <asm/page.h>
  10 #include <asm/export.h>
  11 
  12         /* Zero out 64 bytes of memory at (buf + offset).
  13          * Assumes %g1 contains zero.
  14          */
  15 #define BLAST_BLOCK(buf, offset) \
  16         std     %g0, [buf + offset + 0x38]; \
  17         std     %g0, [buf + offset + 0x30]; \
  18         std     %g0, [buf + offset + 0x28]; \
  19         std     %g0, [buf + offset + 0x20]; \
  20         std     %g0, [buf + offset + 0x18]; \
  21         std     %g0, [buf + offset + 0x10]; \
  22         std     %g0, [buf + offset + 0x08]; \
  23         std     %g0, [buf + offset + 0x00];
  24 
  25         /* Copy 32 bytes of memory at (src + offset) to
  26          * (dst + offset).
  27          */
  28 #define MIRROR_BLOCK(dst, src, offset, t0, t1, t2, t3, t4, t5, t6, t7) \
  29         ldd     [src + offset + 0x18], t0; \
  30         ldd     [src + offset + 0x10], t2; \
  31         ldd     [src + offset + 0x08], t4; \
  32         ldd     [src + offset + 0x00], t6; \
  33         std     t0, [dst + offset + 0x18]; \
  34         std     t2, [dst + offset + 0x10]; \
  35         std     t4, [dst + offset + 0x08]; \
  36         std     t6, [dst + offset + 0x00];
  37 
  38         /* Profiling evidence indicates that memset() is
  39          * commonly called for blocks of size PAGE_SIZE,
  40          * and (2 * PAGE_SIZE) (for kernel stacks)
  41          * and with a second arg of zero.  We assume in
  42          * all of these cases that the buffer is aligned
  43          * on at least an 8 byte boundary.
  44          *
  45          * Therefore we special case them to make them
  46          * as fast as possible.
  47          */
  48 
  49         .text
  50 ENTRY(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 ENDPROC(bzero_1page)
  69 EXPORT_SYMBOL(bzero_1page)
  70 
  71 ENTRY(__copy_1page)
  72 /* NOTE: If you change the number of insns of this routine, please check
  73  * arch/sparc/mm/hypersparc.S */
  74         /* %o0 = dst, %o1 = src */
  75         or      %g0, (PAGE_SIZE >> 8), %g1
  76 1:
  77         MIRROR_BLOCK(%o0, %o1, 0x00, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  78         MIRROR_BLOCK(%o0, %o1, 0x20, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  79         MIRROR_BLOCK(%o0, %o1, 0x40, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  80         MIRROR_BLOCK(%o0, %o1, 0x60, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  81         MIRROR_BLOCK(%o0, %o1, 0x80, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  82         MIRROR_BLOCK(%o0, %o1, 0xa0, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  83         MIRROR_BLOCK(%o0, %o1, 0xc0, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  84         MIRROR_BLOCK(%o0, %o1, 0xe0, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)
  85         subcc   %g1, 1, %g1
  86         add     %o0, 0x100, %o0
  87         bne     1b
  88          add    %o1, 0x100, %o1
  89 
  90         retl
  91          nop
  92 ENDPROC(__copy_1page)
  93 EXPORT_SYMBOL(__copy_1page)