arch/mips/lib/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  * Copyright (C) 2007  Maciej W. Rozycki
   9  */
  10 #include <asm/asm.h>
  11 #include <asm/asm-offsets.h>
  12 #include <asm/regdef.h>
  13
  14 #if LONGSIZE == 4
  15 #define LONG_S_L swl
  16 #define LONG_S_R swr
  17 #else
  18 #define LONG_S_L sdl
  19 #define LONG_S_R sdr
  20 #endif
  21
  22 #define EX(insn,reg,addr,handler)                       \
  23 9:      insn    reg, addr;                              \
  24         .section __ex_table,"a";                        \
  25         PTR     9b, handler;                            \
  26         .previous
  27
  28         .macro  f_fill64 dst, offset, val, fixup
  29         EX(LONG_S, \val, (\offset +  0 * LONGSIZE)(\dst), \fixup)
  30         EX(LONG_S, \val, (\offset +  1 * LONGSIZE)(\dst), \fixup)
  31         EX(LONG_S, \val, (\offset +  2 * LONGSIZE)(\dst), \fixup)
  32         EX(LONG_S, \val, (\offset +  3 * LONGSIZE)(\dst), \fixup)
  33         EX(LONG_S, \val, (\offset +  4 * LONGSIZE)(\dst), \fixup)
  34         EX(LONG_S, \val, (\offset +  5 * LONGSIZE)(\dst), \fixup)
  35         EX(LONG_S, \val, (\offset +  6 * LONGSIZE)(\dst), \fixup)
  36         EX(LONG_S, \val, (\offset +  7 * LONGSIZE)(\dst), \fixup)
  37 #if LONGSIZE == 4
  38         EX(LONG_S, \val, (\offset +  8 * LONGSIZE)(\dst), \fixup)
  39         EX(LONG_S, \val, (\offset +  9 * LONGSIZE)(\dst), \fixup)
  40         EX(LONG_S, \val, (\offset + 10 * LONGSIZE)(\dst), \fixup)
  41         EX(LONG_S, \val, (\offset + 11 * LONGSIZE)(\dst), \fixup)
  42         EX(LONG_S, \val, (\offset + 12 * LONGSIZE)(\dst), \fixup)
  43         EX(LONG_S, \val, (\offset + 13 * LONGSIZE)(\dst), \fixup)
  44         EX(LONG_S, \val, (\offset + 14 * LONGSIZE)(\dst), \fixup)
  45         EX(LONG_S, \val, (\offset + 15 * LONGSIZE)(\dst), \fixup)
  46 #endif
  47         .endm
  48
  49 /*
  50  * memset(void *s, int c, size_t n)
  51  *
  52  * a0: start of area to clear
  53  * a1: char to fill with
  54  * a2: size of area to clear
  55  */
  56         .set    noreorder
  57         .align  5
  58 LEAF(memset)
  59         beqz            a1, 1f
  60          move           v0, a0                  /* result */
  61
  62         andi            a1, 0xff                /* spread fillword */
  63         LONG_SLL                t1, a1, 8
  64         or              a1, t1
  65         LONG_SLL                t1, a1, 16
  66 #if LONGSIZE == 8
  67         or              a1, t1
  68         LONG_SLL                t1, a1, 32
  69 #endif
  70         or              a1, t1
  71 1:
  72
  73 FEXPORT(__bzero)
  74         sltiu           t0, a2, LONGSIZE        /* very small region? */
  75         bnez            t0, .Lsmall_memset
  76          andi           t0, a0, LONGMASK        /* aligned? */
  77
  78 #ifndef CONFIG_CPU_DADDI_WORKAROUNDS
  79         beqz            t0, 1f
  80          PTR_SUBU       t0, LONGSIZE            /* alignment in bytes */
  81 #else
  82         .set            noat
  83         li              AT, LONGSIZE
  84         beqz            t0, 1f
  85          PTR_SUBU       t0, AT                  /* alignment in bytes */
  86         .set            at
  87 #endif
  88
  89         R10KCBARRIER(0(ra))
  90 #ifdef __MIPSEB__
  91         EX(LONG_S_L, a1, (a0), .Lfirst_fixup)   /* make word/dword aligned */
  92 #endif
  93 #ifdef __MIPSEL__
  94         EX(LONG_S_R, a1, (a0), .Lfirst_fixup)   /* make word/dword aligned */
  95 #endif
  96         PTR_SUBU        a0, t0                  /* long align ptr */
  97         PTR_ADDU        a2, t0                  /* correct size */
  98
  99 1:      ori             t1, a2, 0x3f            /* # of full blocks */
 100         xori            t1, 0x3f
 101         beqz            t1, .Lmemset_partial    /* no block to fill */
 102          andi           t0, a2, 0x40-LONGSIZE
 103
 104         PTR_ADDU        t1, a0                  /* end address */
 105         .set            reorder
 106 1:      PTR_ADDIU       a0, 64
 107         R10KCBARRIER(0(ra))
 108         f_fill64 a0, -64, a1, .Lfwd_fixup
 109         bne             t1, a0, 1b
 110         .set            noreorder
 111
 112 .Lmemset_partial:
 113         R10KCBARRIER(0(ra))
 114         PTR_LA          t1, 2f                  /* where to start */
 115 #if LONGSIZE == 4
 116         PTR_SUBU        t1, t0
 117 #else
 118         .set            noat
 119         LONG_SRL                AT, t0, 1
 120         PTR_SUBU        t1, AT
 121         .set            at
 122 #endif
 123         jr              t1
 124          PTR_ADDU       a0, t0                  /* dest ptr */
 125
 126         .set            push
 127         .set            noreorder
 128         .set            nomacro
 129         f_fill64 a0, -64, a1, .Lpartial_fixup   /* ... but first do longs ... */
 130 2:      .set            pop
 131         andi            a2, LONGMASK            /* At most one long to go */
 132
 133         beqz            a2, 1f
 134          PTR_ADDU       a0, a2                  /* What's left */
 135         R10KCBARRIER(0(ra))
 136 #ifdef __MIPSEB__
 137         EX(LONG_S_R, a1, -1(a0), .Llast_fixup)
 138 #endif
 139 #ifdef __MIPSEL__
 140         EX(LONG_S_L, a1, -1(a0), .Llast_fixup)
 141 #endif
 142 1:      jr              ra
 143          move           a2, zero
 144
 145 .Lsmall_memset:
 146         beqz            a2, 2f
 147          PTR_ADDU       t1, a0, a2
 148
 149 1:      PTR_ADDIU       a0, 1                   /* fill bytewise */
 150         R10KCBARRIER(0(ra))
 151         bne             t1, a0, 1b
 152          sb             a1, -1(a0)
 153
 154 2:      jr              ra                      /* done */
 155          move           a2, zero
 156         END(memset)
 157
 158 .Lfirst_fixup:
 159         jr      ra
 160          nop
 161
 162 .Lfwd_fixup:
 163         PTR_L           t0, TI_TASK($28)
 164         LONG_L          t0, THREAD_BUADDR(t0)
 165         andi            a2, 0x3f
 166         LONG_ADDU       a2, t1
 167         jr              ra
 168          LONG_SUBU      a2, t0
 169
 170 .Lpartial_fixup:
 171         PTR_L           t0, TI_TASK($28)
 172         LONG_L          t0, THREAD_BUADDR(t0)
 173         andi            a2, LONGMASK
 174         LONG_ADDU       a2, t1
 175         jr              ra
 176          LONG_SUBU      a2, t0
 177
 178 .Llast_fixup:
 179         jr              ra
 180          andi           v1, a2, LONGMASK