arch/sparc/lib/memset.S

   1 /* linux/arch/sparc/lib/memset.S: Sparc optimized memset, bzero and clear_user code
   2  * Copyright (C) 1991,1996 Free Software Foundation
   3  * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
   4  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
   5  *
   6  * Calls to memset returns initial %o0. Calls to bzero returns 0, if ok, and
   7  * number of bytes not yet set if exception occurs and we were called as
   8  * clear_user.
   9  */
  10
  11 #include <asm/ptrace.h>
  12
  13 /* Work around cpp -rob */
  14 #define ALLOC #alloc
  15 #define EXECINSTR #execinstr
  16 #define EX(x,y,a,b)                             \
  17 98:     x,y;                                    \
  18         .section .fixup,ALLOC,EXECINSTR;        \
  19         .align  4;                              \
  20 99:     ba 30f;                                 \
  21          a, b, %o0;                             \
  22         .section __ex_table,ALLOC;              \
  23         .align  4;                              \
  24         .word   98b, 99b;                       \
  25         .text;                                  \
  26         .align  4
  27
  28 #define EXT(start,end,handler)                  \
  29         .section __ex_table,ALLOC;              \
  30         .align  4;                              \
  31         .word   start, 0, end, handler;         \
  32         .text;                                  \
  33         .align  4
  34
  35 /* Please don't change these macros, unless you change the logic
  36  * in the .fixup section below as well.
  37  * Store 64 bytes at (BASE + OFFSET) using value SOURCE. */
  38 #define ZERO_BIG_BLOCK(base, offset, source)    \
  39         std     source, [base + offset + 0x00]; \
  40         std     source, [base + offset + 0x08]; \
  41         std     source, [base + offset + 0x10]; \
  42         std     source, [base + offset + 0x18]; \
  43         std     source, [base + offset + 0x20]; \
  44         std     source, [base + offset + 0x28]; \
  45         std     source, [base + offset + 0x30]; \
  46         std     source, [base + offset + 0x38];
  47
  48 #define ZERO_LAST_BLOCKS(base, offset, source)  \
  49         std     source, [base - offset - 0x38]; \
  50         std     source, [base - offset - 0x30]; \
  51         std     source, [base - offset - 0x28]; \
  52         std     source, [base - offset - 0x20]; \
  53         std     source, [base - offset - 0x18]; \
  54         std     source, [base - offset - 0x10]; \
  55         std     source, [base - offset - 0x08]; \
  56         std     source, [base - offset - 0x00];
  57
  58         .text
  59         .align 4
  60
  61         .globl  __bzero_begin
  62 __bzero_begin:
  63
  64         .globl  __bzero
  65         .globl  memset
  66         .globl  __memset_start, __memset_end
  67 __memset_start:
  68 memset:
  69         mov     %o0, %g1
  70         mov     1, %g4
  71         and     %o1, 0xff, %g3
  72         sll     %g3, 8, %g2
  73         or      %g3, %g2, %g3
  74         sll     %g3, 16, %g2
  75         or      %g3, %g2, %g3
  76         b       1f
  77          mov    %o2, %o1
  78 3:
  79         cmp     %o2, 3
  80         be      2f
  81          EX(stb %g3, [%o0], sub %o1, 0)
  82
  83         cmp     %o2, 2
  84         be      2f
  85          EX(stb %g3, [%o0 + 0x01], sub %o1, 1)
  86
  87         EX(stb  %g3, [%o0 + 0x02], sub %o1, 2)
  88 2:
  89         sub     %o2, 4, %o2
  90         add     %o1, %o2, %o1
  91         b       4f
  92          sub    %o0, %o2, %o0
  93
  94 __bzero:
  95         clr     %g4
  96         mov     %g0, %g3
  97 1:
  98         cmp     %o1, 7
  99         bleu    7f
 100          andcc  %o0, 3, %o2
 101
 102         bne     3b
 103 4:
 104          andcc  %o0, 4, %g0
 105
 106         be      2f
 107          mov    %g3, %g2
 108
 109         EX(st   %g3, [%o0], sub %o1, 0)
 110         sub     %o1, 4, %o1
 111         add     %o0, 4, %o0
 112 2:
 113         andcc   %o1, 0xffffff80, %o3    ! Now everything is 8 aligned and o1 is len to run
 114         be      9f
 115          andcc  %o1, 0x78, %o2
 116 10:
 117         ZERO_BIG_BLOCK(%o0, 0x00, %g2)
 118         subcc   %o3, 128, %o3
 119         ZERO_BIG_BLOCK(%o0, 0x40, %g2)
 120 11:
 121         EXT(10b, 11b, 20f)
 122         bne     10b
 123          add    %o0, 128, %o0
 124
 125         orcc    %o2, %g0, %g0
 126 9:
 127         be      13f
 128          andcc  %o1, 7, %o1
 129
 130         srl     %o2, 1, %o3
 131         set     13f, %o4
 132         sub     %o4, %o3, %o4
 133         jmp     %o4
 134          add    %o0, %o2, %o0
 135
 136 12:
 137         ZERO_LAST_BLOCKS(%o0, 0x48, %g2)
 138         ZERO_LAST_BLOCKS(%o0, 0x08, %g2)
 139 13:
 140         be      8f
 141          andcc  %o1, 4, %g0
 142
 143         be      1f
 144          andcc  %o1, 2, %g0
 145
 146         EX(st   %g3, [%o0], and %o1, 7)
 147         add     %o0, 4, %o0
 148 1:
 149         be      1f
 150          andcc  %o1, 1, %g0
 151
 152         EX(sth  %g3, [%o0], and %o1, 3)
 153         add     %o0, 2, %o0
 154 1:
 155         bne,a   8f
 156          EX(stb %g3, [%o0], and %o1, 1)
 157 8:
 158         b       0f
 159          nop
 160 7:
 161         be      13b
 162          orcc   %o1, 0, %g0
 163
 164         be      0f
 165 8:
 166          add    %o0, 1, %o0
 167         subcc   %o1, 1, %o1
 168         bne     8b
 169          EX(stb %g3, [%o0 - 1], add %o1, 1)
 170 0:
 171         andcc   %g4, 1, %g0
 172         be      5f
 173          nop
 174         retl
 175          mov    %g1, %o0
 176 5:
 177         retl
 178          clr    %o0
 179 __memset_end:
 180
 181         .section .fixup,#alloc,#execinstr
 182         .align  4
 183 20:
 184         cmp     %g2, 8
 185         bleu    1f
 186          and    %o1, 0x7f, %o1
 187         sub     %g2, 9, %g2
 188         add     %o3, 64, %o3
 189 1:
 190         sll     %g2, 3, %g2
 191         add     %o3, %o1, %o0
 192         b 30f
 193          sub    %o0, %g2, %o0
 194 21:
 195         mov     8, %o0
 196         and     %o1, 7, %o1
 197         sub     %o0, %g2, %o0
 198         sll     %o0, 3, %o0
 199         b 30f
 200          add    %o0, %o1, %o0
 201 30:
 202 /* %o4 is faulting address, %o5 is %pc where fault occurred */
 203         save    %sp, -104, %sp
 204         mov     %i5, %o0
 205         mov     %i7, %o1
 206         call    lookup_fault
 207          mov    %i4, %o2
 208         ret
 209          restore
 210
 211         .globl __bzero_end
 212 __bzero_end: