linux/arch/sparc/lib/memset.S
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2/* linux/arch/sparc/lib/memset.S: Sparc optimized memset, bzero and clear_user code
   3 * Copyright (C) 1991,1996 Free Software Foundation
   4 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
   5 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
   6 *
   7 * Calls to memset returns initial %o0. Calls to bzero returns 0, if ok, and
   8 * number of bytes not yet set if exception occurs and we were called as
   9 * clear_user.
  10 */
  11
  12#include <asm/ptrace.h>
  13#include <asm/export.h>
  14
  15/* Work around cpp -rob */
  16#define ALLOC #alloc
  17#define EXECINSTR #execinstr
  18#define EX(x,y,a,b)                             \
  1998:     x,y;                                    \
  20        .section .fixup,ALLOC,EXECINSTR;        \
  21        .align  4;                              \
  2299:     ba 30f;                                 \
  23         a, b, %o0;                             \
  24        .section __ex_table,ALLOC;              \
  25        .align  4;                              \
  26        .word   98b, 99b;                       \
  27        .text;                                  \
  28        .align  4
  29
  30#define EXT(start,end,handler)                  \
  31        .section __ex_table,ALLOC;              \
  32        .align  4;                              \
  33        .word   start, 0, end, handler;         \
  34        .text;                                  \
  35        .align  4
  36
  37/* Please don't change these macros, unless you change the logic
  38 * in the .fixup section below as well.
  39 * Store 64 bytes at (BASE + OFFSET) using value SOURCE. */
  40#define ZERO_BIG_BLOCK(base, offset, source)    \
  41        std     source, [base + offset + 0x00]; \
  42        std     source, [base + offset + 0x08]; \
  43        std     source, [base + offset + 0x10]; \
  44        std     source, [base + offset + 0x18]; \
  45        std     source, [base + offset + 0x20]; \
  46        std     source, [base + offset + 0x28]; \
  47        std     source, [base + offset + 0x30]; \
  48        std     source, [base + offset + 0x38];
  49
  50#define ZERO_LAST_BLOCKS(base, offset, source)  \
  51        std     source, [base - offset - 0x38]; \
  52        std     source, [base - offset - 0x30]; \
  53        std     source, [base - offset - 0x28]; \
  54        std     source, [base - offset - 0x20]; \
  55        std     source, [base - offset - 0x18]; \
  56        std     source, [base - offset - 0x10]; \
  57        std     source, [base - offset - 0x08]; \
  58        std     source, [base - offset - 0x00];
  59
  60        .text
  61        .align 4
  62
  63        .globl  __bzero_begin
  64__bzero_begin:
  65
  66        .globl  __bzero
  67        .type   __bzero,#function
  68        .globl  memset
  69        EXPORT_SYMBOL(__bzero)
  70        EXPORT_SYMBOL(memset)
  71        .globl  __memset_start, __memset_end
  72__memset_start:
  73memset:
  74        mov     %o0, %g1
  75        mov     1, %g4
  76        and     %o1, 0xff, %g3
  77        sll     %g3, 8, %g2
  78        or      %g3, %g2, %g3
  79        sll     %g3, 16, %g2
  80        or      %g3, %g2, %g3
  81        b       1f
  82         mov    %o2, %o1
  833:
  84        cmp     %o2, 3
  85        be      2f
  86         EX(stb %g3, [%o0], sub %o1, 0)
  87
  88        cmp     %o2, 2
  89        be      2f
  90         EX(stb %g3, [%o0 + 0x01], sub %o1, 1)
  91
  92        EX(stb  %g3, [%o0 + 0x02], sub %o1, 2)
  932:
  94        sub     %o2, 4, %o2
  95        add     %o1, %o2, %o1
  96        b       4f
  97         sub    %o0, %o2, %o0
  98
  99__bzero:
 100        clr     %g4
 101        mov     %g0, %g3
 1021:
 103        cmp     %o1, 7
 104        bleu    7f
 105         andcc  %o0, 3, %o2
 106
 107        bne     3b
 1084:
 109         andcc  %o0, 4, %g0
 110
 111        be      2f
 112         mov    %g3, %g2
 113
 114        EX(st   %g3, [%o0], sub %o1, 0)
 115        sub     %o1, 4, %o1
 116        add     %o0, 4, %o0
 1172:
 118        andcc   %o1, 0xffffff80, %o3    ! Now everything is 8 aligned and o1 is len to run
 119        be      9f
 120         andcc  %o1, 0x78, %o2
 12110:
 122        ZERO_BIG_BLOCK(%o0, 0x00, %g2)
 123        subcc   %o3, 128, %o3
 124        ZERO_BIG_BLOCK(%o0, 0x40, %g2)
 12511:
 126        EXT(10b, 11b, 20f)
 127        bne     10b
 128         add    %o0, 128, %o0
 129
 130        orcc    %o2, %g0, %g0
 1319:
 132        be      13f
 133         andcc  %o1, 7, %o1
 134
 135        srl     %o2, 1, %o3
 136        set     13f, %o4
 137        sub     %o4, %o3, %o4
 138        jmp     %o4
 139         add    %o0, %o2, %o0
 140
 14112:
 142        ZERO_LAST_BLOCKS(%o0, 0x48, %g2)
 143        ZERO_LAST_BLOCKS(%o0, 0x08, %g2)
 14413:
 145        be      8f
 146         andcc  %o1, 4, %g0
 147
 148        be      1f
 149         andcc  %o1, 2, %g0
 150
 151        EX(st   %g3, [%o0], and %o1, 7)
 152        add     %o0, 4, %o0
 1531:
 154        be      1f
 155         andcc  %o1, 1, %g0
 156
 157        EX(sth  %g3, [%o0], and %o1, 3)
 158        add     %o0, 2, %o0
 1591:
 160        bne,a   8f
 161         EX(stb %g3, [%o0], and %o1, 1)
 1628:
 163        b       0f
 164         nop
 1657:
 166        be      13b
 167         orcc   %o1, 0, %g0
 168
 169        be      0f
 1708:
 171         add    %o0, 1, %o0
 172        subcc   %o1, 1, %o1
 173        bne     8b
 174         EX(stb %g3, [%o0 - 1], add %o1, 1)
 1750:
 176        andcc   %g4, 1, %g0
 177        be      5f
 178         nop
 179        retl
 180         mov    %g1, %o0
 1815:
 182        retl
 183         clr    %o0
 184__memset_end:
 185
 186        .section .fixup,#alloc,#execinstr
 187        .align  4
 18820:
 189        cmp     %g2, 8
 190        bleu    1f
 191         and    %o1, 0x7f, %o1
 192        sub     %g2, 9, %g2
 193        add     %o3, 64, %o3
 1941:
 195        sll     %g2, 3, %g2
 196        add     %o3, %o1, %o0
 197        b 30f
 198         sub    %o0, %g2, %o0
 19921:
 200        mov     8, %o0
 201        and     %o1, 7, %o1
 202        sub     %o0, %g2, %o0
 203        sll     %o0, 3, %o0
 204        b 30f
 205         add    %o0, %o1, %o0
 20630:
 207/* %o4 is faulting address, %o5 is %pc where fault occurred */
 208        save    %sp, -104, %sp
 209        mov     %i5, %o0
 210        mov     %i7, %o1
 211        call    lookup_fault
 212         mov    %i4, %o2
 213        ret
 214         restore
 215
 216        .globl __bzero_end
 217__bzero_end:
 218