1 /* $NetBSD: bzero.S,v 1.15 2016/12/19 14:30:23 christos Exp $ */ 2 3 /*- 4 * Copyright (C) 2001 Martin J. Laubach <mjl (at) NetBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 /*----------------------------------------------------------------------*/ 30 31 #include <machine/asm.h> 32 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 __RCSID("$NetBSD: bzero.S,v 1.15 2016/12/19 14:30:23 christos Exp $") 36 #endif /* LIBC_SCCS && !lint */ 37 38 #include "assym.h" 39 40 #define USE_STSWX 0 /* don't. slower than trivial copy loop */ 41 42 /*----------------------------------------------------------------------*/ 43 /* 44 void bzero(void *b %r3, size_t len %r4); 45 void * memset(void *b %r3, int c %r4, size_t len %r5); 46 */ 47 /*----------------------------------------------------------------------*/ 48 49 #define r_dst %r3 50 #define r_len %r4 51 #define r_val %r0 52 53 .text 54 .align 4 55 ENTRY(bzero) 56 li r_val, 0 /* Value to stuff in */ 57 cmplwi %cr1, %r4, 0 /* Zero length? */ 58 beqlr- %cr1 /* Yes, do nothing */ 59 b cb_memset 60 END(bzero) 61 62 ENTRY(memset) 63 cmplwi %cr1, %r5, 0 64 mr. %r0, %r4 65 mr %r8, %r3 66 beqlr- %cr1 /* Nothing to do */ 67 68 rlwimi %r0, %r4, 8, 16, 23 /* word extend fill value */ 69 rlwimi %r0, %r0, 16, 0, 15 70 mr %r4, %r5 71 bne- simple_fill /* =! 0, use trivial fill */ 72 cb_memset: 73 74 /*----------------------------------------------------------------------*/ 75 #ifndef _KERNEL 76 #ifdef __PIC__ 77 /* First get cache line size */ 78 mflr %r9 79 bcl 20,31,1f 80 1: mflr %r10 81 mtlr %r9 82 addis %r10,%r10,_libc_powerpc_cache_info+CACHE_INFO_DCACHE_LINE_SIZE-1b@ha 83 lwz %r9,_libc_powerpc_cache_info+CACHE_INFO_DCACHE_LINE_SIZE-1b@l(%r10) 84 #else 85 lis %r10,_libc_powerpc_cache_info+CACHE_INFO_DCACHE_LINE_SIZE@ha 86 lwz %r9,_libc_powerpc_cache_info+CACHE_INFO_DCACHE_LINE_SIZE@l(%r10) 87 #endif 88 cmplwi %cr1, %r9, 0 /* Unknown? */ 89 beq- simple_fill /* a trivial fill routine */ 90 #else /* _KERNEL */ 91 #ifdef MULTIPROCESSOR 92 mfsprg %r10, 0 /* Get cpu_info pointer */ 93 #else 94 lis %r10, cpu_info_store@ha 95 addi %r10, %r10, cpu_info_store@l 96 #endif 97 lwz %r9, CPU_CI+CACHE_INFO_DCACHE_LINE_SIZE(%r10) /* Load D$ line size */ 98 #endif /* _KERNEL */ 99 cntlzw %r10, %r9 /* Calculate shift.. */ 100 li %r6, 31 101 subf %r10, %r10, %r6 102 /* Back in memory filling business */ 103 104 cmplwi %cr1, r_len, 0 /* Nothing to do? */ 105 add %r5, %r9, %r9 106 cmplw r_len, %r5 /* <= 2*CL bytes to move? */ 107 beqlr- %cr1 /* then do nothing */ 108 109 blt+ simple_fill /* a trivial fill routine */ 110 111 /* Word align the block, fill bytewise until dst even*/ 112 113 andi. %r5, r_dst, 0x03 114 li %r6, 4 115 beq+ cb_aligned_w /* already aligned to word? */ 116 117 subf %r5, %r5, %r6 /* bytes to fill to align4 */ 118 #if USE_STSWX 119 mtxer %r5 120 stswx %r0, 0, r_dst 121 add r_dst, %r5, r_dst 122 #else 123 mtctr %r5 124 125 subi r_dst, r_dst, 1 126 1: stbu r_val, 1(r_dst) /* Fill bytewise */ 127 bdnz 1b 128 129 addi r_dst, r_dst, 1 130 #endif 131 subf r_len, %r5, r_len 132 133 cb_aligned_w: /* Cache block align, fill wordwise until dst aligned */ 134 135 /* I know I have something to do since we had > 2*CL initially */ 136 /* so no need to check for r_len = 0 */ 137 138 subi %r6, %r9, 1 /* CL mask */ 139 and. %r5, r_dst, %r6 140 srwi %r5, %r5, 2 141 srwi %r6, %r9, 2 142 beq cb_aligned_cb /* already on CL boundary? */ 143 144 subf %r5, %r5, %r6 /* words to fill to alignment */ 145 mtctr %r5 146 slwi %r5, %r5, 2 147 subf r_len, %r5, r_len 148 149 subi r_dst, r_dst, 4 150 1: stwu r_val, 4(r_dst) /* Fill wordwise */ 151 bdnz 1b 152 addi r_dst, r_dst, 4 153 154 cb_aligned_cb: /* no need to check r_len, see above */ 155 156 srw. %r5, r_len, %r10 /* Number of cache blocks */ 157 mtctr %r5 158 beq cblocks_done 159 160 slw %r5, %r5, %r10 161 subf r_len, %r5, r_len 162 163 1: dcbz 0, r_dst /* Clear blockwise */ 164 add r_dst, r_dst, %r9 165 bdnz 1b 166 167 cblocks_done: /* still CL aligned, but less than CL bytes left */ 168 cmplwi %cr1, r_len, 0 169 cmplwi r_len, 8 170 beq- %cr1, sf_return 171 172 blt- sf_bytewise /* <8 remaining? */ 173 b sf_aligned_w 174 175 /*----------------------------------------------------------------------*/ 176 wbzero: li r_val, 0 177 178 cmplwi r_len, 0 179 beqlr- /* Nothing to do */ 180 181 simple_fill: 182 #if USE_STSWX 183 cmplwi %cr1, r_len, 12 /* < 12 bytes to move? */ 184 #else 185 cmplwi %cr1, r_len, 8 /* < 8 bytes to move? */ 186 #endif 187 andi. %r5, r_dst, 0x03 /* bytes to fill to align4 */ 188 blt %cr1, sf_bytewise /* trivial byte mover */ 189 190 li %r6, 4 191 subf %r5, %r5, %r6 192 beq+ sf_aligned_w /* dest is word aligned */ 193 194 #if USE_STSWX 195 mtxer %r5 196 stswx %r0, 0, r_dst 197 add r_dst, %r5, r_dst 198 #else 199 mtctr %r5 /* nope, then fill bytewise */ 200 subi r_dst, r_dst, 1 /* until it is */ 201 1: stbu r_val, 1(r_dst) 202 bdnz 1b 203 204 addi r_dst, r_dst, 1 205 #endif 206 subf r_len, %r5, r_len 207 208 sf_aligned_w: /* no need to check r_len since it were >= 8 bytes initially */ 209 #if USE_STSWX 210 mr %r6, %r0 211 mr %r7, %r0 212 213 srwi %r5, r_len, 3 214 mtctr %r5 215 216 slwi %r5, %r5, 3 /* adjust len */ 217 subf. r_len, %r5, r_len 218 219 1: stswi %r6, r_dst, 8 220 addi r_dst, r_dst, 8 221 bdnz 1b 222 #else 223 srwi %r5, r_len, 2 /* words to fill */ 224 mtctr %r5 225 226 slwi %r5, %r5, 2 227 subf. r_len, %r5, r_len /* adjust len for fill */ 228 229 subi r_dst, r_dst, 4 230 1: stwu r_val, 4(r_dst) 231 bdnz 1b 232 addi r_dst, r_dst, 4 233 #endif 234 235 sf_word_done: bne- sf_bytewise 236 237 sf_return: mr %r3, %r8 /* restore orig ptr */ 238 blr /* for memset functionality */ 239 240 sf_bytewise: 241 #if USE_STSWX 242 mr %r5, %r0 243 mr %r6, %r0 244 mr %r7, %r0 245 246 mtxer r_len 247 stswx %r5, 0, r_dst 248 #else 249 mtctr r_len 250 251 subi r_dst, r_dst, 1 252 1: stbu r_val, 1(r_dst) 253 bdnz 1b 254 #endif 255 mr %r3, %r8 /* restore orig ptr */ 256 blr /* for memset functionality */ 257 END(memset) 258 259 /*----------------------------------------------------------------------*/ 260 #ifndef _KERNEL 261 .data 262 .p2align 2 263 cache_info: .long -1, -1, -1, -1 264 cache_sh: .long 0 265 266 #endif 267 /*----------------------------------------------------------------------*/ 268
Indexes created Thu Sep 25 16:09:42 GMT 2025