arch/mips/lib-32/memset.S

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1998, 1999, 2000 by Ralf Baechle
   7  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   8  */
   9 #include <asm/asm.h>
  10 #include <asm/offset.h>
  11 #include <asm/regdef.h>
  12
  13 #define EX(insn,reg,addr,handler)                       \
  14 9:      insn    reg, addr;                              \
  15         .section __ex_table,"a";                        \
  16         PTR     9b, handler;                            \
  17         .previous
  18
  19         .macro  f_fill64 dst, offset, val, fixup
  20         EX(LONG_S, \val, (\offset +  0 * LONGSIZE)(\dst), \fixup)
  21         EX(LONG_S, \val, (\offset +  1 * LONGSIZE)(\dst), \fixup)
  22         EX(LONG_S, \val, (\offset +  2 * LONGSIZE)(\dst), \fixup)
  23         EX(LONG_S, \val, (\offset +  3 * LONGSIZE)(\dst), \fixup)
  24         EX(LONG_S, \val, (\offset +  4 * LONGSIZE)(\dst), \fixup)
  25         EX(LONG_S, \val, (\offset +  5 * LONGSIZE)(\dst), \fixup)
  26         EX(LONG_S, \val, (\offset +  6 * LONGSIZE)(\dst), \fixup)
  27         EX(LONG_S, \val, (\offset +  7 * LONGSIZE)(\dst), \fixup)
  28         EX(LONG_S, \val, (\offset +  8 * LONGSIZE)(\dst), \fixup)
  29         EX(LONG_S, \val, (\offset +  9 * LONGSIZE)(\dst), \fixup)
  30         EX(LONG_S, \val, (\offset + 10 * LONGSIZE)(\dst), \fixup)
  31         EX(LONG_S, \val, (\offset + 11 * LONGSIZE)(\dst), \fixup)
  32         EX(LONG_S, \val, (\offset + 12 * LONGSIZE)(\dst), \fixup)
  33         EX(LONG_S, \val, (\offset + 13 * LONGSIZE)(\dst), \fixup)
  34         EX(LONG_S, \val, (\offset + 14 * LONGSIZE)(\dst), \fixup)
  35         EX(LONG_S, \val, (\offset + 15 * LONGSIZE)(\dst), \fixup)
  36         .endm
  37
  38 /*
  39  * memset(void *s, int c, size_t n)
  40  *
  41  * a0: start of area to clear
  42  * a1: char to fill with
  43  * a2: size of area to clear
  44  */
  45         .set    noreorder
  46         .align  5
  47 LEAF(memset)
  48         beqz            a1, 1f
  49          move           v0, a0                  /* result */
  50
  51         andi            a1, 0xff                /* spread fillword */
  52         sll             t1, a1, 8
  53         or              a1, t1
  54         sll             t1, a1, 16
  55         or              a1, t1
  56 1:
  57
  58 FEXPORT(__bzero)
  59         sltiu           t0, a2, LONGSIZE        /* very small region? */
  60         bnez            t0, small_memset
  61          andi           t0, a0, LONGMASK        /* aligned? */
  62
  63         beqz            t0, 1f
  64          PTR_SUBU       t0, LONGSIZE            /* alignment in bytes */
  65
  66 #ifdef __MIPSEB__
  67         EX(swl, a1, (a0), first_fixup)          /* make word aligned */
  68 #endif
  69 #ifdef __MIPSEL__
  70         EX(swr, a1, (a0), first_fixup)          /* make word aligned */
  71 #endif
  72         PTR_SUBU        a0, t0                  /* long align ptr */
  73         PTR_ADDU        a2, t0                  /* correct size */
  74
  75 1:      ori             t1, a2, 0x3f            /* # of full blocks */
  76         xori            t1, 0x3f
  77         beqz            t1, memset_partial      /* no block to fill */
  78          andi           t0, a2, 0x3c
  79
  80         PTR_ADDU        t1, a0                  /* end address */
  81         .set            reorder
  82 1:      PTR_ADDIU       a0, 64
  83         f_fill64 a0, -64, a1, fwd_fixup
  84         bne             t1, a0, 1b
  85         .set            noreorder
  86
  87 memset_partial:
  88         PTR_LA          t1, 2f                  /* where to start */
  89         PTR_SUBU        t1, t0
  90         jr              t1
  91          PTR_ADDU       a0, t0                  /* dest ptr */
  92
  93         .set            push
  94         .set            noreorder
  95         .set            nomacro
  96         f_fill64 a0, -64, a1, partial_fixup     /* ... but first do longs ... */
  97 2:      .set            pop
  98         andi            a2, LONGMASK            /* At most one long to go */
  99
 100         beqz            a2, 1f
 101          PTR_ADDU       a0, a2                  /* What's left */
 102 #ifdef __MIPSEB__
 103         EX(swr, a1, -1(a0), last_fixup)
 104 #endif
 105 #ifdef __MIPSEL__
 106         EX(swl, a1, -1(a0), last_fixup)
 107 #endif
 108 1:      jr              ra
 109          move           a2, zero
 110
 111 small_memset:
 112         beqz            a2, 2f
 113          PTR_ADDU       t1, a0, a2
 114
 115 1:      PTR_ADDIU       a0, 1                   /* fill bytewise */
 116         bne             t1, a0, 1b
 117          sb             a1, -1(a0)
 118
 119 2:      jr              ra                      /* done */
 120          move           a2, zero
 121         END(memset)
 122
 123 first_fixup:
 124         jr      ra
 125          nop
 126
 127 fwd_fixup:
 128         PTR_L           t0, TI_TASK($28)
 129         LONG_L          t0, THREAD_BUADDR(t0)
 130         andi            a2, 0x3f
 131         LONG_ADDU       a2, t1
 132         jr              ra
 133          LONG_SUBU      a2, t0
 134
 135 partial_fixup:
 136         PTR_L           t0, TI_TASK($28)
 137         LONG_L          t0, THREAD_BUADDR(t0)
 138         andi            a2, LONGMASK
 139         LONG_ADDU       a2, t1
 140         jr              ra
 141          LONG_SUBU      a2, t0
 142
 143 last_fixup:
 144         jr              ra
 145          andi           v1, a2, LONGMASK