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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 | /* SPDX-License-Identifier: GPL-2.0-or-later */ /* * User Space Access Routines * * Copyright (C) 2000-2002 Hewlett-Packard (John Marvin) * Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org> * Copyright (C) 2001 Matthieu Delahaye <delahaym at esiee.fr> * Copyright (C) 2003 Randolph Chung <tausq with parisc-linux.org> * Copyright (C) 2017 Helge Deller <deller@gmx.de> * Copyright (C) 2017 John David Anglin <dave.anglin@bell.net> */ /* * These routines still have plenty of room for optimization * (word & doubleword load/store, dual issue, store hints, etc.). */ /* * The following routines assume that space register 3 (sr3) contains * the space id associated with the current users address space. */ .text #include <asm/assembly.h> #include <asm/errno.h> #include <linux/linkage.h> /* * unsigned long lclear_user(void *to, unsigned long n) * * Returns 0 for success. * otherwise, returns number of bytes not transferred. */ ENTRY_CFI(lclear_user) comib,=,n 0,%r25,$lclu_done $lclu_loop: addib,<> -1,%r25,$lclu_loop 1: stbs,ma %r0,1(%sr3,%r26) $lclu_done: bv %r0(%r2) copy %r25,%r28 2: b $lclu_done ldo 1(%r25),%r25 ASM_EXCEPTIONTABLE_ENTRY(1b,2b) ENDPROC_CFI(lclear_user) /* * unsigned long pa_memcpy(void *dstp, const void *srcp, unsigned long len) * * Inputs: * - sr1 already contains space of source region * - sr2 already contains space of destination region * * Returns: * - number of bytes that could not be copied. * On success, this will be zero. * * This code is based on a C-implementation of a copy routine written by * Randolph Chung, which in turn was derived from the glibc. * * Several strategies are tried to try to get the best performance for various * conditions. In the optimal case, we copy by loops that copy 32- or 16-bytes * at a time using general registers. Unaligned copies are handled either by * aligning the destination and then using shift-and-write method, or in a few * cases by falling back to a byte-at-a-time copy. * * Testing with various alignments and buffer sizes shows that this code is * often >10x faster than a simple byte-at-a-time copy, even for strangely * aligned operands. It is interesting to note that the glibc version of memcpy * (written in C) is actually quite fast already. This routine is able to beat * it by 30-40% for aligned copies because of the loop unrolling, but in some * cases the glibc version is still slightly faster. This lends more * credibility that gcc can generate very good code as long as we are careful. * * Possible optimizations: * - add cache prefetching * - try not to use the post-increment address modifiers; they may create * additional interlocks. Assumption is that those were only efficient on old * machines (pre PA8000 processors) */ dst = arg0 src = arg1 len = arg2 end = arg3 t1 = r19 t2 = r20 t3 = r21 t4 = r22 srcspc = sr1 dstspc = sr2 t0 = r1 a1 = t1 a2 = t2 a3 = t3 a0 = t4 save_src = ret0 save_dst = ret1 save_len = r31 ENTRY_CFI(pa_memcpy) /* Last destination address */ add dst,len,end /* short copy with less than 16 bytes? */ cmpib,COND(>>=),n 15,len,.Lbyte_loop /* same alignment? */ xor src,dst,t0 extru t0,31,2,t1 cmpib,<>,n 0,t1,.Lunaligned_copy #ifdef CONFIG_64BIT /* only do 64-bit copies if we can get aligned. */ extru t0,31,3,t1 cmpib,<>,n 0,t1,.Lalign_loop32 /* loop until we are 64-bit aligned */ .Lalign_loop64: extru dst,31,3,t1 cmpib,=,n 0,t1,.Lcopy_loop_16_start 20: ldb,ma 1(srcspc,src),t1 21: stb,ma t1,1(dstspc,dst) b .Lalign_loop64 ldo -1(len),len ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done) .Lcopy_loop_16_start: ldi 31,t0 .Lcopy_loop_16: cmpb,COND(>>=),n t0,len,.Lword_loop 10: ldd 0(srcspc,src),t1 11: ldd 8(srcspc,src),t2 ldo 16(src),src 12: std,ma t1,8(dstspc,dst) 13: std,ma t2,8(dstspc,dst) 14: ldd 0(srcspc,src),t1 15: ldd 8(srcspc,src),t2 ldo 16(src),src 16: std,ma t1,8(dstspc,dst) 17: std,ma t2,8(dstspc,dst) ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(11b,.Lcopy16_fault) ASM_EXCEPTIONTABLE_ENTRY(12b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(13b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(14b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(15b,.Lcopy16_fault) ASM_EXCEPTIONTABLE_ENTRY(16b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(17b,.Lcopy_done) b .Lcopy_loop_16 ldo -32(len),len .Lword_loop: cmpib,COND(>>=),n 3,len,.Lbyte_loop 20: ldw,ma 4(srcspc,src),t1 21: stw,ma t1,4(dstspc,dst) b .Lword_loop ldo -4(len),len ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done) #endif /* CONFIG_64BIT */ /* loop until we are 32-bit aligned */ .Lalign_loop32: extru dst,31,2,t1 cmpib,=,n 0,t1,.Lcopy_loop_8 20: ldb,ma 1(srcspc,src),t1 21: stb,ma t1,1(dstspc,dst) b .Lalign_loop32 ldo -1(len),len ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done) .Lcopy_loop_8: cmpib,COND(>>=),n 15,len,.Lbyte_loop 10: ldw 0(srcspc,src),t1 11: ldw 4(srcspc,src),t2 12: stw,ma t1,4(dstspc,dst) 13: stw,ma t2,4(dstspc,dst) 14: ldw 8(srcspc,src),t1 15: ldw 12(srcspc,src),t2 ldo 16(src),src 16: stw,ma t1,4(dstspc,dst) 17: stw,ma t2,4(dstspc,dst) ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(11b,.Lcopy8_fault) ASM_EXCEPTIONTABLE_ENTRY(12b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(13b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(14b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(15b,.Lcopy8_fault) ASM_EXCEPTIONTABLE_ENTRY(16b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(17b,.Lcopy_done) b .Lcopy_loop_8 ldo -16(len),len .Lbyte_loop: cmpclr,COND(<>) len,%r0,%r0 b,n .Lcopy_done 20: ldb 0(srcspc,src),t1 ldo 1(src),src 21: stb,ma t1,1(dstspc,dst) b .Lbyte_loop ldo -1(len),len ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done) .Lcopy_done: bv %r0(%r2) sub end,dst,ret0 /* src and dst are not aligned the same way. */ /* need to go the hard way */ .Lunaligned_copy: /* align until dst is 32bit-word-aligned */ extru dst,31,2,t1 cmpib,=,n 0,t1,.Lcopy_dstaligned 20: ldb 0(srcspc,src),t1 ldo 1(src),src 21: stb,ma t1,1(dstspc,dst) b .Lunaligned_copy ldo -1(len),len ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done) ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done) .Lcopy_dstaligned: /* store src, dst and len in safe place */ copy src,save_src copy dst,save_dst copy len,save_len /* len now needs give number of words to copy */ SHRREG len,2,len /* * Copy from a not-aligned src to an aligned dst using shifts. * Handles 4 words per loop. */ depw,z src,28,2,t0 subi 32,t0,t0 mtsar t0 extru len,31,2,t0 cmpib,= 2,t0,.Lcase2 /* Make src aligned by rounding it down. */ depi 0,31,2,src cmpiclr,<> 3,t0,%r0 b,n .Lcase3 cmpiclr,<> 1,t0,%r0 b,n .Lcase1 .Lcase0: cmpb,COND(=) %r0,len,.Lcda_finish nop 1: ldw,ma 4(srcspc,src), a3 ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault) 1: ldw,ma 4(srcspc,src), a0 ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault) b,n .Ldo3 .Lcase1: 1: ldw,ma 4(srcspc,src), a2 ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault) 1: ldw,ma 4(srcspc,src), a3 ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault) ldo -1(len),len cmpb,COND(=),n %r0,len,.Ldo0 .Ldo4: 1: ldw,ma 4(srcspc,src), a0 ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault) shrpw a2, a3, %sar, t0 1: stw,ma t0, 4(dstspc,dst) ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done) .Ldo3: 1: ldw,ma 4(srcspc,src), a1 ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault) shrpw a3, a0, %sar, t0 1: stw,ma t0, 4(dstspc,dst) ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done) .Ldo2: 1: ldw,ma 4(srcspc,src), a2 ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault) shrpw a0, a1, %sar, t0 1: stw,ma t0, 4(dstspc,dst) ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done) .Ldo1: 1: ldw,ma 4(srcspc,src), a3 ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault) shrpw a1, a2, %sar, t0 1: stw,ma t0, 4(dstspc,dst) ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done) ldo -4(len),len cmpb,COND(<>) %r0,len,.Ldo4 nop .Ldo0: shrpw a2, a3, %sar, t0 1: stw,ma t0, 4(dstspc,dst) ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done) .Lcda_rdfault: .Lcda_finish: /* calculate new src, dst and len and jump to byte-copy loop */ sub dst,save_dst,t0 add save_src,t0,src b .Lbyte_loop sub save_len,t0,len .Lcase3: 1: ldw,ma 4(srcspc,src), a0 ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault) 1: ldw,ma 4(srcspc,src), a1 ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault) b .Ldo2 ldo 1(len),len .Lcase2: 1: ldw,ma 4(srcspc,src), a1 ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault) 1: ldw,ma 4(srcspc,src), a2 ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault) b .Ldo1 ldo 2(len),len /* fault exception fixup handlers: */ #ifdef CONFIG_64BIT .Lcopy16_fault: b .Lcopy_done 10: std,ma t1,8(dstspc,dst) ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done) #endif .Lcopy8_fault: b .Lcopy_done 10: stw,ma t1,4(dstspc,dst) ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done) ENDPROC_CFI(pa_memcpy) .end |