copyout.c revision 1.4
1 /* $NetBSD: copyout.c,v 1.4 2014/07/24 23:29:02 joerg Exp $ */ 2 3 /*- 4 * Copyright (c) 2010, 2011 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Raytheon BBN Technologies Corp and Defense Advanced Research Projects 9 * Agency and which was developed by Matt Thomas of 3am Software Foundry. 10 * 11 * This material is based upon work supported by the Defense Advanced Research 12 * Projects Agency and Space and Naval Warfare Systems Center, Pacific, under 13 * Contract No. N66001-09-C-2073. 14 * Approved for Public Release, Distribution Unlimited 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 26 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 * POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 #include <sys/cdefs.h> 39 __KERNEL_RCSID(0, "$NetBSD: copyout.c,v 1.4 2014/07/24 23:29:02 joerg Exp $"); 40 41 #include <sys/param.h> 42 #include <sys/lwp.h> 43 44 #include <powerpc/pcb.h> 45 46 #include <powerpc/booke/cpuvar.h> 47 48 static inline void 49 copyout_uint8(uint8_t *udaddr, uint8_t data, register_t ds_msr) 50 { 51 register_t msr; 52 __asm volatile( 53 "mfmsr %[msr]" /* Save MSR */ 54 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 55 "\n\t" "stb %[data],0(%[udaddr])" /* store user byte */ 56 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 57 : [msr] "=&r" (msr) 58 : [ds_msr] "r" (ds_msr), [data] "r" (data), [udaddr] "b" (udaddr)); 59 } 60 61 #if 0 62 static inline void 63 copyout_uint16(uint8_t *udaddr, uint8_t data, register_t ds_msr) 64 { 65 register_t msr; 66 __asm volatile( 67 "mfmsr %[msr]" /* Save MSR */ 68 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 69 "\n\t" "stb %[data],0(%[udaddr])" /* store user byte */ 70 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 71 : [msr] "=&r" (msr) 72 : [ds_msr] "r" (ds_msr), [data] "r" (data), [udaddr] "b" (udaddr)); 73 } 74 #endif 75 76 static inline void 77 copyout_uint32(uint32_t * const udaddr, uint32_t data, register_t ds_msr) 78 { 79 register_t msr; 80 __asm volatile( 81 "mfmsr %[msr]" /* Save MSR */ 82 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 83 "\n\t" "stw %[data],0(%[udaddr])" /* store user data */ 84 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 85 : [msr] "=&r" (msr) 86 : [ds_msr] "r" (ds_msr), [data] "r" (data), [udaddr] "b" (udaddr)); 87 } 88 89 #if 0 90 static inline void 91 copyout_le32(uint32_t * const udaddr, uint32_t data, register_t ds_msr) 92 { 93 register_t msr; 94 __asm volatile( 95 "mfmsr %[msr]" /* Save MSR */ 96 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 97 "\n\t" "stwbrx %[data],0,%[udaddr]" /* store user data */ 98 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 99 : [msr] "=&r" (msr) 100 : [ds_msr] "r" (ds_msr), [data] "r" (data), [udaddr] "b" (udaddr)); 101 } 102 103 static inline void 104 copyout_le32_with_mask(uint32_t * const udaddr, uint32_t data, 105 uint32_t mask, register_t ds_msr) 106 { 107 register_t msr; 108 uint32_t tmp; 109 KASSERT((data & ~mask) == 0); 110 __asm volatile( 111 "mfmsr %[msr]" /* Save MSR */ 112 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 113 "\n\t" "lwbrx %[tmp],0,%[udaddr]" /* fetch user data */ 114 "\n\t" "andc %[tmp],%[tmp],%[mask]" /* mask out new data */ 115 "\n\t" "or %[tmp],%[tmp],%[data]" /* merge new data */ 116 "\n\t" "stwbrx %[tmp],0,%[udaddr]" /* store user data */ 117 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 118 : [msr] "=&r" (msr), [tmp] "=&r" (tmp) 119 : [ds_msr] "r" (ds_msr), [data] "r" (data), 120 [mask] "r" (mask), [udaddr] "b" (udaddr)); 121 } 122 #endif 123 124 static inline void 125 copyout_16uint8s(const uint8_t *ksaddr8, uint8_t *udaddr8, register_t ds_msr) 126 { 127 register_t msr; 128 __asm volatile( 129 "mfmsr %[msr]" /* Save MSR */ 130 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 131 "\n\t" "stb %[data0],0(%[udaddr8])" /* store user data */ 132 "\n\t" "stb %[data1],1(%[udaddr8])" /* store user data */ 133 "\n\t" "stb %[data2],2(%[udaddr8])" /* store user data */ 134 "\n\t" "stb %[data3],3(%[udaddr8])" /* store user data */ 135 "\n\t" "stb %[data4],4(%[udaddr8])" /* store user data */ 136 "\n\t" "stb %[data5],5(%[udaddr8])" /* store user data */ 137 "\n\t" "stb %[data6],6(%[udaddr8])" /* store user data */ 138 "\n\t" "stb %[data7],7(%[udaddr8])" /* store user data */ 139 "\n\t" "stb %[data8],8(%[udaddr8])" /* store user data */ 140 "\n\t" "stb %[data9],9(%[udaddr8])" /* store user data */ 141 "\n\t" "stb %[data10],10(%[udaddr8])" /* store user data */ 142 "\n\t" "stb %[data11],11(%[udaddr8])" /* store user data */ 143 "\n\t" "stb %[data12],12(%[udaddr8])" /* store user data */ 144 "\n\t" "stb %[data13],13(%[udaddr8])" /* store user data */ 145 "\n\t" "stb %[data14],14(%[udaddr8])" /* store user data */ 146 "\n\t" "stb %[data15],15(%[udaddr8])" /* store user data */ 147 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 148 : [msr] "=&r" (msr) 149 : [ds_msr] "r" (ds_msr), [udaddr8] "b" (udaddr8), 150 [data0] "r" (ksaddr8[0]), [data1] "r" (ksaddr8[1]), 151 [data2] "r" (ksaddr8[2]), [data3] "r" (ksaddr8[3]), 152 [data4] "r" (ksaddr8[4]), [data5] "r" (ksaddr8[5]), 153 [data6] "r" (ksaddr8[6]), [data7] "r" (ksaddr8[7]), 154 [data8] "r" (ksaddr8[8]), [data9] "r" (ksaddr8[9]), 155 [data10] "r" (ksaddr8[10]), [data11] "r" (ksaddr8[11]), 156 [data12] "r" (ksaddr8[12]), [data13] "r" (ksaddr8[13]), 157 [data14] "r" (ksaddr8[14]), [data15] "r" (ksaddr8[15])); 158 } 159 160 static inline void 161 copyout_8uint32s(const uint32_t * const ksaddr32, uint32_t * const udaddr32, 162 const register_t ds_msr, const size_t line_mask) 163 { 164 register_t msr; 165 register_t tmp; 166 __asm volatile( 167 "and. %[tmp],%[line_mask],%[udaddr32]" 168 "\n\t" "mfmsr %[msr]" /* Save MSR */ 169 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 170 "\n\t" "bne 0,1f" 171 "\n\t" "dcba 0,%[udaddr32]" 172 "\n" "1:" 173 "\n\t" "stw %[data0],0(%[udaddr32])" /* store user data */ 174 "\n\t" "stw %[data1],4(%[udaddr32])" /* store user data */ 175 "\n\t" "stw %[data2],8(%[udaddr32])" /* store user data */ 176 "\n\t" "stw %[data3],12(%[udaddr32])" /* store user data */ 177 "\n\t" "stw %[data4],16(%[udaddr32])" /* store user data */ 178 "\n\t" "stw %[data5],20(%[udaddr32])" /* store user data */ 179 "\n\t" "stw %[data6],24(%[udaddr32])" /* store user data */ 180 "\n\t" "stw %[data7],28(%[udaddr32])" /* store user data */ 181 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 182 : [msr] "=&r" (msr), [tmp] "=&r" (tmp) 183 : [ds_msr] "r" (ds_msr), [udaddr32] "b" (udaddr32), 184 [line_mask] "r" (line_mask), 185 [data0] "r" (ksaddr32[0]), [data1] "r" (ksaddr32[1]), 186 [data2] "r" (ksaddr32[2]), [data3] "r" (ksaddr32[3]), 187 [data4] "r" (ksaddr32[4]), [data5] "r" (ksaddr32[5]), 188 [data6] "r" (ksaddr32[6]), [data7] "r" (ksaddr32[7]) 189 : "cr0"); 190 } 191 192 static inline void 193 copyout_16uint32s(const uint32_t * const ksaddr32, uint32_t * const udaddr32, 194 const register_t ds_msr, const size_t line_mask) 195 { 196 KASSERT(((uintptr_t)udaddr32 & line_mask) == 0); 197 register_t msr; 198 register_t tmp; 199 __asm volatile( 200 "and. %[tmp],%[line_mask],%[udaddr32]" 201 "\n\t" "cmplwi 2,%[line_size],32" 202 "\n\t" "mfmsr %[msr]" /* Save MSR */ 203 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 204 "\n\t" "bne 0,1f" 205 "\n\t" "dcba 0,%[udaddr32]" 206 "\n\t" "bne 2,1f" 207 "\n\t" "dcba %[line_size],%[udaddr32]" 208 "\n" "1:" 209 "\n\t" "stw %[data0],0(%[udaddr32])" /* store user data */ 210 "\n\t" "stw %[data1],4(%[udaddr32])" /* store user data */ 211 "\n\t" "stw %[data2],8(%[udaddr32])" /* store user data */ 212 "\n\t" "stw %[data3],12(%[udaddr32])" /* store user data */ 213 "\n\t" "stw %[data4],16(%[udaddr32])" /* store user data */ 214 "\n\t" "stw %[data5],20(%[udaddr32])" /* store user data */ 215 "\n\t" "stw %[data6],24(%[udaddr32])" /* store user data */ 216 "\n\t" "stw %[data7],28(%[udaddr32])" /* store user data */ 217 "\n\t" "stw %[data8],32(%[udaddr32])" /* store user data */ 218 "\n\t" "stw %[data9],36(%[udaddr32])" /* store user data */ 219 "\n\t" "stw %[data10],40(%[udaddr32])" /* store user data */ 220 "\n\t" "stw %[data11],44(%[udaddr32])" /* store user data */ 221 "\n\t" "stw %[data12],48(%[udaddr32])" /* store user data */ 222 "\n\t" "stw %[data13],52(%[udaddr32])" /* store user data */ 223 "\n\t" "stw %[data14],56(%[udaddr32])" /* store user data */ 224 "\n\t" "stw %[data15],60(%[udaddr32])" /* store user data */ 225 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 226 : [msr] "=&r" (msr), [tmp] "=&r" (tmp) 227 : [ds_msr] "r" (ds_msr), [udaddr32] "b" (udaddr32), 228 [line_size] "r" (line_mask + 1), [line_mask] "r" (line_mask), 229 [data0] "r" (ksaddr32[0]), [data1] "r" (ksaddr32[1]), 230 [data2] "r" (ksaddr32[2]), [data3] "r" (ksaddr32[3]), 231 [data4] "r" (ksaddr32[4]), [data5] "r" (ksaddr32[5]), 232 [data6] "r" (ksaddr32[6]), [data7] "r" (ksaddr32[7]), 233 [data8] "r" (ksaddr32[8]), [data9] "r" (ksaddr32[9]), 234 [data10] "r" (ksaddr32[10]), [data11] "r" (ksaddr32[11]), 235 [data12] "r" (ksaddr32[12]), [data13] "r" (ksaddr32[13]), 236 [data14] "r" (ksaddr32[14]), [data15] "r" (ksaddr32[15]) 237 : "cr0", "cr2"); 238 } 239 240 static inline void 241 copyout_uint8s(vaddr_t ksaddr, vaddr_t udaddr, size_t len, register_t ds_msr) 242 { 243 const uint8_t *ksaddr8 = (void *)ksaddr; 244 uint8_t *udaddr8 = (void *)udaddr; 245 246 __builtin_prefetch(ksaddr8, 0, 1); 247 248 for (; len >= 16; len -= 16, ksaddr8 += 16, udaddr8 += 16) { 249 __builtin_prefetch(ksaddr8 + 16, 0, 1); 250 copyout_16uint8s(ksaddr8, udaddr8, ds_msr); 251 } 252 253 while (len-- > 0) { 254 copyout_uint8(udaddr8++, *ksaddr8++, ds_msr); 255 } 256 } 257 258 static inline void 259 copyout_uint32s(vaddr_t ksaddr, vaddr_t udaddr, size_t len, register_t ds_msr) 260 { 261 const size_t line_size = curcpu()->ci_ci.dcache_line_size; 262 const size_t line_mask = line_size - 1; 263 const size_t udalignment = udaddr & line_mask; 264 KASSERT((ksaddr & 3) == 0); 265 KASSERT((udaddr & 3) == 0); 266 const uint32_t *ksaddr32 = (void *)ksaddr; 267 uint32_t *udaddr32 = (void *)udaddr; 268 len >>= 2; 269 __builtin_prefetch(ksaddr32, 0, 1); 270 if (udalignment != 0 && udalignment + 4*len > line_size) { 271 size_t slen = (line_size - udalignment) >> 2; 272 len -= slen; 273 for (; slen >= 8; ksaddr32 += 8, udaddr32 += 8, slen -= 8) { 274 copyout_8uint32s(ksaddr32, udaddr32, ds_msr, line_mask); 275 } 276 while (slen-- > 0) { 277 copyout_uint32(udaddr32++, *ksaddr32++, ds_msr); 278 } 279 if (len == 0) 280 return; 281 } 282 __builtin_prefetch(ksaddr32, 0, 1); 283 while (len >= 16) { 284 __builtin_prefetch(ksaddr32 + 8, 0, 1); 285 __builtin_prefetch(ksaddr32 + 16, 0, 1); 286 copyout_16uint32s(ksaddr32, udaddr32, ds_msr, line_mask); 287 ksaddr32 += 16, udaddr32 += 16, len -= 16; 288 } 289 KASSERT(len <= 16); 290 if (len >= 8) { 291 __builtin_prefetch(ksaddr32 + 8, 0, 1); 292 copyout_8uint32s(ksaddr32, udaddr32, ds_msr, line_mask); 293 ksaddr32 += 8, udaddr32 += 8, len -= 8; 294 } 295 while (len-- > 0) { 296 copyout_uint32(udaddr32++, *ksaddr32++, ds_msr); 297 } 298 } 299 300 int 301 copyout(const void *vksaddr, void *vudaddr, size_t len) 302 { 303 struct pcb * const pcb = lwp_getpcb(curlwp); 304 struct faultbuf env; 305 vaddr_t udaddr = (vaddr_t) vudaddr; 306 vaddr_t ksaddr = (vaddr_t) vksaddr; 307 308 if (__predict_false(len == 0)) { 309 return 0; 310 } 311 312 const register_t ds_msr = mfmsr() | PSL_DS; 313 314 int rv = setfault(&env); 315 if (rv != 0) { 316 pcb->pcb_onfault = NULL; 317 return rv; 318 } 319 320 if (__predict_false(len < 4)) { 321 copyout_uint8s(ksaddr, udaddr, len, ds_msr); 322 pcb->pcb_onfault = NULL; 323 return 0; 324 } 325 326 const size_t alignment = (udaddr ^ ksaddr) & 3; 327 if (__predict_true(alignment == 0)) { 328 size_t slen; 329 if (__predict_false(ksaddr & 3)) { 330 slen = 4 - (ksaddr & 3); 331 copyout_uint8s(ksaddr, udaddr, slen, ds_msr); 332 udaddr += slen, ksaddr += slen, len -= slen; 333 } 334 slen = len & ~3; 335 if (__predict_true(slen >= 4)) { 336 copyout_uint32s(ksaddr, udaddr, slen, ds_msr); 337 udaddr += slen, ksaddr += slen, len -= slen; 338 } 339 } 340 341 if (len > 0) { 342 copyout_uint8s(ksaddr, udaddr, len, ds_msr); 343 } 344 pcb->pcb_onfault = NULL; 345 return 0; 346 } 347 348 int 349 copyoutstr(const void *ksaddr, void *udaddr, size_t len, size_t *lenp) 350 { 351 struct pcb * const pcb = lwp_getpcb(curlwp); 352 struct faultbuf env; 353 354 if (__predict_false(len == 0)) { 355 if (lenp) 356 *lenp = 0; 357 return 0; 358 } 359 360 if (setfault(&env)) { 361 pcb->pcb_onfault = NULL; 362 if (lenp) 363 *lenp = 0; 364 return EFAULT; 365 } 366 367 const register_t ds_msr = mfmsr() | PSL_DS; 368 const uint8_t *ksaddr8 = ksaddr; 369 size_t copylen = 0; 370 371 #if 1 372 uint8_t *udaddr8 = (void *)udaddr; 373 374 while (copylen++ < len) { 375 const uint8_t data = *ksaddr8++; 376 copyout_uint8(udaddr8++, data, ds_msr); 377 if (data == 0) 378 break; 379 } 380 #else 381 uint32_t *udaddr32 = (void *)((uintptr_t)udaddr & ~3); 382 383 size_t boff = (uintptr_t)udaddr & 3; 384 bool done = false; 385 size_t wlen = 0; 386 size_t data = 0; 387 388 /* 389 * If the destination buffer doesn't start on a 32-bit boundary 390 * try to partially fill in the first word. If we succeed we can 391 * finish writing it while preserving the bytes on front. 392 */ 393 if (boff > 0) { 394 KASSERT(len > 0); 395 do { 396 data = (data << 8) | *ksaddr8++; 397 wlen++; 398 done = ((uint8_t)data == 0 || len == wlen); 399 } while (!done && boff + wlen < 4); 400 KASSERT(wlen > 0); 401 data <<= 8 * boff; 402 if (!done || boff + wlen == 4) { 403 uint32_t mask = 0xffffffff << (8 * boff); 404 copyout_le32_with_mask(udaddr32++, data, mask, ds_msr); 405 boff = 0; 406 copylen = wlen; 407 wlen = 0; 408 data = 0; 409 } 410 } 411 412 /* 413 * Now we get to the heart of the routine. Build up complete words 414 * if possible. When we have one, write it to the user's address 415 * space and go for the next. If we ran out of space or we found the 416 * end of the string, stop building. If we managed to build a complete 417 * word, just write it and be happy. Otherwise we have to deal with 418 * the trailing bytes. 419 */ 420 KASSERT(done || boff == 0); 421 KASSERT(done || copylen < len); 422 while (!done) { 423 KASSERT(wlen == 0); 424 KASSERT(copylen < len); 425 do { 426 data = (data << 8) | *ksaddr8++; 427 wlen++; 428 done = ((uint8_t)data == 0 || copylen + wlen == len); 429 } while (!done && wlen < 4); 430 KASSERT(done || wlen == 4); 431 if (__predict_true(wlen == 4)) { 432 copyout_le32(udaddr32++, data, ds_msr); 433 data = 0; 434 copylen += wlen; 435 wlen = 0; 436 KASSERT(copylen < len || done); 437 } 438 } 439 KASSERT(wlen < 3); 440 if (wlen) { 441 /* 442 * Remember even though we are running big-endian we are using 443 * byte reversed load/stores so we need to deal with things as 444 * little endian. 445 * 446 * wlen=1 boff=0: 447 * (~(~0 << 8) << 0) -> (~(0xffffff00) << 0) -> 0x000000ff 448 * wlen=1 boff=1: 449 * (~(~0 << 8) << 8) -> (~(0xffffff00) << 8) -> 0x0000ff00 450 * wlen=1 boff=2: 451 * (~(~0 << 8) << 16) -> (~(0xffffff00) << 16) -> 0x00ff0000 452 * wlen=1 boff=3: 453 * (~(~0 << 8) << 24) -> (~(0xffffff00) << 24) -> 0xff000000 454 * wlen=2 boff=0: 455 * (~(~0 << 16) << 0) -> (~(0xffff0000) << 0) -> 0x0000ffff 456 * wlen=2 boff=1: 457 * (~(~0 << 16) << 8) -> (~(0xffff0000) << 8) -> 0x00ffff00 458 * wlen=2 boff=2: 459 * (~(~0 << 16) << 16) -> (~(0xffff0000) << 16) -> 0xffff0000 460 * wlen=3 boff=0: 461 * (~(~0 << 24) << 0) -> (~(0xff000000) << 0) -> 0x00ffffff 462 * wlen=3 boff=1: 463 * (~(~0 << 24) << 8) -> (~(0xff000000) << 8) -> 0xffffff00 464 */ 465 KASSERT(boff + wlen <= 4); 466 uint32_t mask = (~(~0 << (8 * wlen))) << (8 * boff); 467 KASSERT(mask != 0xffffffff); 468 copyout_le32_with_mask(udaddr32, data, mask, ds_msr); 469 copylen += wlen; 470 } 471 #endif 472 473 pcb->pcb_onfault = NULL; 474 if (lenp) 475 *lenp = copylen; 476 return 0; 477 } 478
Indexes created Tue Sep 30 20:09:53 GMT 2025