root/arch/powerpc/boot/string.S

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * Copyright (C) Paul Mackerras 1997.
   4  *
   5  * NOTE: this code runs in 32 bit mode and is packaged as ELF32.
   6  */
   7 
   8 #include "ppc_asm.h"
   9 
  10         .text
  11         .globl  strcpy
  12 strcpy:
  13         addi    r5,r3,-1
  14         addi    r4,r4,-1
  15 1:      lbzu    r0,1(r4)
  16         cmpwi   0,r0,0
  17         stbu    r0,1(r5)
  18         bne     1b
  19         blr
  20 
  21         .globl  strncpy
  22 strncpy:
  23         cmpwi   0,r5,0
  24         beqlr
  25         mtctr   r5
  26         addi    r6,r3,-1
  27         addi    r4,r4,-1
  28 1:      lbzu    r0,1(r4)
  29         cmpwi   0,r0,0
  30         stbu    r0,1(r6)
  31         bdnzf   2,1b            /* dec ctr, branch if ctr != 0 && !cr0.eq */
  32         blr
  33 
  34         .globl  strcat
  35 strcat:
  36         addi    r5,r3,-1
  37         addi    r4,r4,-1
  38 1:      lbzu    r0,1(r5)
  39         cmpwi   0,r0,0
  40         bne     1b
  41         addi    r5,r5,-1
  42 1:      lbzu    r0,1(r4)
  43         cmpwi   0,r0,0
  44         stbu    r0,1(r5)
  45         bne     1b
  46         blr
  47 
  48         .globl  strchr
  49 strchr:
  50         addi    r3,r3,-1
  51 1:      lbzu    r0,1(r3)
  52         cmpw    0,r0,r4
  53         beqlr
  54         cmpwi   0,r0,0
  55         bne     1b
  56         li      r3,0
  57         blr
  58 
  59         .globl  strcmp
  60 strcmp:
  61         addi    r5,r3,-1
  62         addi    r4,r4,-1
  63 1:      lbzu    r3,1(r5)
  64         cmpwi   1,r3,0
  65         lbzu    r0,1(r4)
  66         subf.   r3,r0,r3
  67         beqlr   1
  68         beq     1b
  69         blr
  70 
  71         .globl  strncmp
  72 strncmp:
  73         mtctr   r5
  74         addi    r5,r3,-1
  75         addi    r4,r4,-1
  76 1:      lbzu    r3,1(r5)
  77         cmpwi   1,r3,0
  78         lbzu    r0,1(r4)
  79         subf.   r3,r0,r3
  80         beqlr   1
  81         bdnzt   eq,1b
  82         blr
  83 
  84         .globl  strlen
  85 strlen:
  86         addi    r4,r3,-1
  87 1:      lbzu    r0,1(r4)
  88         cmpwi   0,r0,0
  89         bne     1b
  90         subf    r3,r3,r4
  91         blr
  92 
  93         .globl  memset
  94 memset:
  95         rlwimi  r4,r4,8,16,23
  96         rlwimi  r4,r4,16,0,15
  97         addi    r6,r3,-4
  98         cmplwi  0,r5,4
  99         blt     7f
 100         stwu    r4,4(r6)
 101         beqlr
 102         andi.   r0,r6,3
 103         add     r5,r0,r5
 104         subf    r6,r0,r6
 105         rlwinm  r0,r5,32-2,2,31
 106         mtctr   r0
 107         bdz     6f
 108 1:      stwu    r4,4(r6)
 109         bdnz    1b
 110 6:      andi.   r5,r5,3
 111 7:      cmpwi   0,r5,0
 112         beqlr
 113         mtctr   r5
 114         addi    r6,r6,3
 115 8:      stbu    r4,1(r6)
 116         bdnz    8b
 117         blr
 118 
 119         .globl  memmove
 120 memmove:
 121         cmplw   0,r3,r4
 122         bgt     backwards_memcpy
 123         /* fall through */
 124 
 125         .globl  memcpy
 126 memcpy:
 127         rlwinm. r7,r5,32-3,3,31         /* r7 = r5 >> 3 */
 128         addi    r6,r3,-4
 129         addi    r4,r4,-4
 130         beq     3f                      /* if less than 8 bytes to do */
 131         andi.   r0,r6,3                 /* get dest word aligned */
 132         mtctr   r7
 133         bne     5f
 134         andi.   r0,r4,3                 /* check src word aligned too */
 135         bne     3f
 136 1:      lwz     r7,4(r4)
 137         lwzu    r8,8(r4)
 138         stw     r7,4(r6)
 139         stwu    r8,8(r6)
 140         bdnz    1b
 141         andi.   r5,r5,7
 142 2:      cmplwi  0,r5,4
 143         blt     3f
 144         lwzu    r0,4(r4)
 145         addi    r5,r5,-4
 146         stwu    r0,4(r6)
 147 3:      cmpwi   0,r5,0
 148         beqlr
 149         mtctr   r5
 150         addi    r4,r4,3
 151         addi    r6,r6,3
 152 4:      lbzu    r0,1(r4)
 153         stbu    r0,1(r6)
 154         bdnz    4b
 155         blr
 156 5:      subfic  r0,r0,4
 157         cmpw    cr1,r0,r5
 158         add     r7,r0,r4
 159         andi.   r7,r7,3                 /* will source be word-aligned too? */
 160         ble     cr1,3b
 161         bne     3b                      /* do byte-by-byte if not */
 162         mtctr   r0
 163 6:      lbz     r7,4(r4)
 164         addi    r4,r4,1
 165         stb     r7,4(r6)
 166         addi    r6,r6,1
 167         bdnz    6b
 168         subf    r5,r0,r5
 169         rlwinm. r7,r5,32-3,3,31
 170         beq     2b
 171         mtctr   r7
 172         b       1b
 173 
 174         .globl  backwards_memcpy
 175 backwards_memcpy:
 176         rlwinm. r7,r5,32-3,3,31         /* r7 = r5 >> 3 */
 177         add     r6,r3,r5
 178         add     r4,r4,r5
 179         beq     3f
 180         andi.   r0,r6,3
 181         mtctr   r7
 182         bne     5f
 183         andi.   r0,r4,3
 184         bne     3f
 185 1:      lwz     r7,-4(r4)
 186         lwzu    r8,-8(r4)
 187         stw     r7,-4(r6)
 188         stwu    r8,-8(r6)
 189         bdnz    1b
 190         andi.   r5,r5,7
 191 2:      cmplwi  0,r5,4
 192         blt     3f
 193         lwzu    r0,-4(r4)
 194         subi    r5,r5,4
 195         stwu    r0,-4(r6)
 196 3:      cmpwi   0,r5,0
 197         beqlr
 198         mtctr   r5
 199 4:      lbzu    r0,-1(r4)
 200         stbu    r0,-1(r6)
 201         bdnz    4b
 202         blr
 203 5:      cmpw    cr1,r0,r5
 204         subf    r7,r0,r4
 205         andi.   r7,r7,3
 206         ble     cr1,3b
 207         bne     3b
 208         mtctr   r0
 209 6:      lbzu    r7,-1(r4)
 210         stbu    r7,-1(r6)
 211         bdnz    6b
 212         subf    r5,r0,r5
 213         rlwinm. r7,r5,32-3,3,31
 214         beq     2b
 215         mtctr   r7
 216         b       1b
 217 
 218         .globl  memchr
 219 memchr:
 220         cmpwi   0,r5,0
 221         blelr
 222         mtctr   r5
 223         addi    r3,r3,-1
 224 1:      lbzu    r0,1(r3)
 225         cmpw    r0,r4
 226         beqlr
 227         bdnz    1b
 228         li      r3,0
 229         blr
 230 
 231         .globl  memcmp
 232 memcmp:
 233         cmpwi   0,r5,0
 234         ble     2f
 235         mtctr   r5
 236         addi    r6,r3,-1
 237         addi    r4,r4,-1
 238 1:      lbzu    r3,1(r6)
 239         lbzu    r0,1(r4)
 240         subf.   r3,r0,r3
 241         bdnzt   2,1b
 242         blr
 243 2:      li      r3,0
 244         blr
 245 
 246 
 247 /*
 248  * Flush the dcache and invalidate the icache for a range of addresses.
 249  *
 250  * flush_cache(addr, len)
 251  */
 252         .global flush_cache
 253 flush_cache:
 254         addi    4,4,0x1f        /* len = (len + 0x1f) / 0x20 */
 255         rlwinm. 4,4,27,5,31
 256         mtctr   4
 257         beqlr
 258 1:      dcbf    0,3
 259         icbi    0,3
 260         addi    3,3,0x20
 261         bdnz    1b
 262         sync
 263         isync
 264         blr
 265