arch/mips/lib-64/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         .endm
  29
  30 /*
  31  * memset(void *s, int c, size_t n)
  32  *
  33  * a0: start of area to clear
  34  * a1: char to fill with
  35  * a2: size of area to clear
  36  */
  37         .set    noreorder
  38         .align  5
  39 LEAF(memset)
  40         beqz            a1, 1f
  41          move           v0, a0                  /* result */
  42
  43         andi            a1, 0xff                /* spread fillword */
  44         dsll            t1, a1, 8
  45         or              a1, t1
  46         dsll            t1, a1, 16
  47         or              a1, t1
  48         dsll            t1, a1, 32
  49         or              a1, t1
  50 1:
  51
  52 FEXPORT(__bzero)
  53         sltiu           t0, a2, LONGSIZE        /* very small region? */
  54         bnez            t0, small_memset
  55          andi           t0, a0, LONGMASK        /* aligned? */
  56
  57         beqz            t0, 1f
  58          PTR_SUBU       t0, LONGSIZE            /* alignment in bytes */
  59
  60 #ifdef __MIPSEB__
  61         EX(sdl, a1, (a0), first_fixup)          /* make dword aligned */
  62 #endif
  63 #ifdef __MIPSEL__
  64         EX(sdr, a1, (a0), first_fixup)          /* make dword aligned */
  65 #endif
  66         PTR_SUBU        a0, t0                  /* long align ptr */
  67         PTR_ADDU        a2, t0                  /* correct size */
  68
  69 1:      ori             t1, a2, 0x3f            /* # of full blocks */
  70         xori            t1, 0x3f
  71         beqz            t1, memset_partial      /* no block to fill */
  72          andi           t0, a2, 0x38
  73
  74         PTR_ADDU        t1, a0                  /* end address */
  75         .set            reorder
  76 1:      PTR_ADDIU       a0, 64
  77         f_fill64 a0, -64, a1, fwd_fixup
  78         bne             t1, a0, 1b
  79         .set            noreorder
  80
  81 memset_partial:
  82         PTR_LA          t1, 2f                  /* where to start */
  83         .set            noat
  84         dsrl            AT, t0, 1
  85         PTR_SUBU        t1, AT
  86         .set            noat
  87         jr              t1
  88          PTR_ADDU       a0, t0                  /* dest ptr */
  89
  90         .set            push
  91         .set            noreorder
  92         .set            nomacro
  93         f_fill64 a0, -64, a1, partial_fixup     /* ... but first do longs ... */
  94 2:      .set            pop
  95         andi            a2, LONGMASK            /* At most one long to go */
  96
  97         beqz            a2, 1f
  98          PTR_ADDU       a0, a2                  /* What's left */
  99 #ifdef __MIPSEB__
 100         EX(sdr, a1, -1(a0), last_fixup)
 101 #endif
 102 #ifdef __MIPSEL__
 103         EX(sdl, a1, -1(a0), last_fixup)
 104 #endif
 105 1:      jr              ra
 106          move           a2, zero
 107
 108 small_memset:
 109         beqz            a2, 2f
 110          PTR_ADDU       t1, a0, a2
 111
 112 1:      PTR_ADDIU       a0, 1                   /* fill bytewise */
 113         bne             t1, a0, 1b
 114          sb             a1, -1(a0)
 115
 116 2:      jr              ra                      /* done */
 117          move           a2, zero
 118         END(memset)
 119
 120 first_fixup:
 121         jr      ra
 122          nop
 123
 124 fwd_fixup:
 125         PTR_L           t0, TI_TASK($28)
 126         LONG_L          t0, THREAD_BUADDR(t0)
 127         andi            a2, 0x3f
 128         LONG_ADDU       a2, t1
 129         jr              ra
 130          LONG_SUBU      a2, t0
 131
 132 partial_fixup:
 133         PTR_L           t0, TI_TASK($28)
 134         LONG_L          t0, THREAD_BUADDR(t0)
 135         andi            a2, LONGMASK
 136         LONG_ADDU       a2, t1
 137         jr              ra
 138          LONG_SUBU      a2, t0
 139
 140 last_fixup:
 141         jr              ra
 142          andi           v1, a2, LONGMASK