1 /* $NetBSD: copyout.c,v 1.2 2011/01/18 01:02:52 matt 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 1.2 2011/01/18 01:02:52 matt Exp $"); 40 41 #include <sys/param.h> 42 #include <sys/lwp.h> 43 44 #include <machine/pcb.h> 45 46 static inline void 47 copyout_uint8(uint8_t *udaddr, uint8_t data, register_t ds_msr) 48 { 49 register_t msr; 50 __asm volatile( 51 "mfmsr %[msr]" /* Save MSR */ 52 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 53 "\n\t" "stb %[data],0(%[udaddr])" /* store user byte */ 54 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 55 : [msr] "=&r" (msr) 56 : [ds_msr] "r" (ds_msr), [data] "r" (data), [udaddr] "b" (udaddr)); 57 } 58 59 static inline void 60 copyout_uint16(uint8_t *udaddr, uint8_t data, register_t ds_msr) 61 { 62 register_t msr; 63 __asm volatile( 64 "mfmsr %[msr]" /* Save MSR */ 65 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 66 "\n\t" "stb %[data],0(%[udaddr])" /* store user byte */ 67 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 68 : [msr] "=&r" (msr) 69 : [ds_msr] "r" (ds_msr), [data] "r" (data), [udaddr] "b" (udaddr)); 70 } 71 72 static inline void 73 copyout_uint32(uint32_t * const udaddr, uint32_t data, register_t ds_msr) 74 { 75 register_t msr; 76 __asm volatile( 77 "mfmsr %[msr]" /* Save MSR */ 78 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 79 "\n\t" "stw %[data],0(%[udaddr])" /* store user data */ 80 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 81 : [msr] "=&r" (msr) 82 : [ds_msr] "r" (ds_msr), [data] "r" (data), [udaddr] "b" (udaddr)); 83 } 84 85 static inline void 86 copyout_le32(uint32_t * const udaddr, uint32_t data, register_t ds_msr) 87 { 88 register_t msr; 89 __asm volatile( 90 "mfmsr %[msr]" /* Save MSR */ 91 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 92 "\n\t" "stwbrx %[data],0,%[udaddr]" /* store user data */ 93 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 94 : [msr] "=&r" (msr) 95 : [ds_msr] "r" (ds_msr), [data] "r" (data), [udaddr] "b" (udaddr)); 96 } 97 98 static inline void 99 copyout_le32_with_mask(uint32_t * const udaddr, uint32_t data, 100 uint32_t mask, register_t ds_msr) 101 { 102 register_t msr; 103 uint32_t tmp; 104 KASSERT((data & ~mask) == 0); 105 __asm volatile( 106 "mfmsr %[msr]" /* Save MSR */ 107 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 108 "\n\t" "lwbrx %[tmp],0,%[udaddr]" /* fetch user data */ 109 "\n\t" "andc %[tmp],%[tmp],%[mask]" /* mask out new data */ 110 "\n\t" "or %[tmp],%[tmp],%[data]" /* merge new data */ 111 "\n\t" "stwbrx %[tmp],0,%[udaddr]" /* store user data */ 112 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 113 : [msr] "=&r" (msr), [tmp] "=&r" (tmp) 114 : [ds_msr] "r" (ds_msr), [data] "r" (data), 115 [mask] "r" (mask), [udaddr] "b" (udaddr)); 116 } 117 118 static inline void 119 copyout_16uint8s(const uint8_t *ksaddr8, uint8_t *udaddr8, register_t ds_msr) 120 { 121 register_t msr; 122 __asm volatile( 123 "mfmsr %[msr]" /* Save MSR */ 124 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 125 "\n\t" "stb %[data0],0(%[udaddr8])" /* store user data */ 126 "\n\t" "stb %[data1],1(%[udaddr8])" /* store user data */ 127 "\n\t" "stb %[data2],2(%[udaddr8])" /* store user data */ 128 "\n\t" "stb %[data3],3(%[udaddr8])" /* store user data */ 129 "\n\t" "stb %[data4],4(%[udaddr8])" /* store user data */ 130 "\n\t" "stb %[data5],5(%[udaddr8])" /* store user data */ 131 "\n\t" "stb %[data6],6(%[udaddr8])" /* store user data */ 132 "\n\t" "stb %[data7],7(%[udaddr8])" /* store user data */ 133 "\n\t" "stb %[data8],8(%[udaddr8])" /* store user data */ 134 "\n\t" "stb %[data9],9(%[udaddr8])" /* store user data */ 135 "\n\t" "stb %[data10],10(%[udaddr8])" /* store user data */ 136 "\n\t" "stb %[data11],11(%[udaddr8])" /* store user data */ 137 "\n\t" "stb %[data12],12(%[udaddr8])" /* store user data */ 138 "\n\t" "stb %[data13],13(%[udaddr8])" /* store user data */ 139 "\n\t" "stb %[data14],14(%[udaddr8])" /* store user data */ 140 "\n\t" "stb %[data15],15(%[udaddr8])" /* store user data */ 141 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 142 : [msr] "=&r" (msr) 143 : [ds_msr] "r" (ds_msr), [udaddr8] "b" (udaddr8), 144 [data0] "r" (ksaddr8[0]), [data1] "r" (ksaddr8[1]), 145 [data2] "r" (ksaddr8[2]), [data3] "r" (ksaddr8[3]), 146 [data4] "r" (ksaddr8[4]), [data5] "r" (ksaddr8[5]), 147 [data6] "r" (ksaddr8[6]), [data7] "r" (ksaddr8[7]), 148 [data8] "r" (ksaddr8[8]), [data9] "r" (ksaddr8[9]), 149 [data10] "r" (ksaddr8[10]), [data11] "r" (ksaddr8[11]), 150 [data12] "r" (ksaddr8[12]), [data13] "r" (ksaddr8[13]), 151 [data14] "r" (ksaddr8[14]), [data15] "r" (ksaddr8[15])); 152 } 153 154 static inline void 155 copyout_8uint32s(const uint32_t * const ksaddr32, uint32_t * const udaddr32, 156 const register_t ds_msr, const size_t line_mask) 157 { 158 register_t msr; 159 register_t tmp; 160 __asm volatile( 161 "and. %[tmp],%[line_mask],%[udaddr32]" 162 "\n\t" "mfmsr %[msr]" /* Save MSR */ 163 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 164 "\n\t" "bne 0,1f" 165 "\n\t" "dcba 0,%[udaddr32]" 166 "\n" "1:" 167 "\n\t" "stw %[data0],0(%[udaddr32])" /* store user data */ 168 "\n\t" "stw %[data1],4(%[udaddr32])" /* store user data */ 169 "\n\t" "stw %[data2],8(%[udaddr32])" /* store user data */ 170 "\n\t" "stw %[data3],12(%[udaddr32])" /* store user data */ 171 "\n\t" "stw %[data4],16(%[udaddr32])" /* store user data */ 172 "\n\t" "stw %[data5],20(%[udaddr32])" /* store user data */ 173 "\n\t" "stw %[data6],24(%[udaddr32])" /* store user data */ 174 "\n\t" "stw %[data7],28(%[udaddr32])" /* store user data */ 175 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 176 : [msr] "=&r" (msr), [tmp] "=&r" (tmp) 177 : [ds_msr] "r" (ds_msr), [udaddr32] "b" (udaddr32), 178 [line_mask] "r" (line_mask), 179 [data0] "r" (ksaddr32[0]), [data1] "r" (ksaddr32[1]), 180 [data2] "r" (ksaddr32[2]), [data3] "r" (ksaddr32[3]), 181 [data4] "r" (ksaddr32[4]), [data5] "r" (ksaddr32[5]), 182 [data6] "r" (ksaddr32[6]), [data7] "r" (ksaddr32[7]) 183 : "cr0"); 184 } 185 186 static inline void 187 copyout_16uint32s(const uint32_t * const ksaddr32, uint32_t * const udaddr32, 188 const register_t ds_msr, const size_t line_mask) 189 { 190 KASSERT(((uintptr_t)udaddr32 & line_mask) == 0); 191 register_t msr; 192 register_t tmp; 193 __asm volatile( 194 "and. %[tmp],%[line_mask],%[udaddr32]" 195 "\n\t" "cmplwi 2,%[line_size],32" 196 "\n\t" "mfmsr %[msr]" /* Save MSR */ 197 "\n\t" "mtmsr %[ds_msr]; sync; isync" /* DS on */ 198 "\n\t" "bne 0,1f" 199 "\n\t" "dcba 0,%[udaddr32]" 200 "\n\t" "bne 2,1f" 201 "\n\t" "dcba %[line_size],%[udaddr32]" 202 "\n" "1:" 203 "\n\t" "stw %[data0],0(%[udaddr32])" /* store user data */ 204 "\n\t" "stw %[data1],4(%[udaddr32])" /* store user data */ 205 "\n\t" "stw %[data2],8(%[udaddr32])" /* store user data */ 206 "\n\t" "stw %[data3],12(%[udaddr32])" /* store user data */ 207 "\n\t" "stw %[data4],16(%[udaddr32])" /* store user data */ 208 "\n\t" "stw %[data5],20(%[udaddr32])" /* store user data */ 209 "\n\t" "stw %[data6],24(%[udaddr32])" /* store user data */ 210 "\n\t" "stw %[data7],28(%[udaddr32])" /* store user data */ 211 "\n\t" "stw %[data8],32(%[udaddr32])" /* store user data */ 212 "\n\t" "stw %[data9],36(%[udaddr32])" /* store user data */ 213 "\n\t" "stw %[data10],40(%[udaddr32])" /* store user data */ 214 "\n\t" "stw %[data11],44(%[udaddr32])" /* store user data */ 215 "\n\t" "stw %[data12],48(%[udaddr32])" /* store user data */ 216 "\n\t" "stw %[data13],52(%[udaddr32])" /* store user data */ 217 "\n\t" "stw %[data14],56(%[udaddr32])" /* store user data */ 218 "\n\t" "stw %[data15],60(%[udaddr32])" /* store user data */ 219 "\n\t" "mtmsr %[msr]; sync; isync" /* DS off */ 220 : [msr] "=&r" (msr), [tmp] "=&r" (tmp) 221 : [ds_msr] "r" (ds_msr), [udaddr32] "b" (udaddr32), 222 [line_size] "r" (line_mask + 1), [line_mask] "r" (line_mask), 223 [data0] "r" (ksaddr32[0]), [data1] "r" (ksaddr32[1]), 224 [data2] "r" (ksaddr32[2]), [data3] "r" (ksaddr32[3]), 225 [data4] "r" (ksaddr32[4]), [data5] "r" (ksaddr32[5]), 226 [data6] "r" (ksaddr32[6]), [data7] "r" (ksaddr32[7]), 227 [data8] "r" (ksaddr32[8]), [data9] "r" (ksaddr32[9]), 228 [data10] "r" (ksaddr32[10]), [data11] "r" (ksaddr32[11]), 229 [data12] "r" (ksaddr32[12]), [data13] "r" (ksaddr32[13]), 230 [data14] "r" (ksaddr32[14]), [data15] "r" (ksaddr32[15]) 231 : "cr0", "cr2"); 232 } 233 234 static inline void 235 copyout_uint8s(vaddr_t ksaddr, vaddr_t udaddr, size_t len, register_t ds_msr) 236 { 237 const uint8_t *ksaddr8 = (void *)ksaddr; 238 uint8_t *udaddr8 = (void *)udaddr; 239 240 __builtin_prefetch(ksaddr8, 0, 1); 241 242 for (; len >= 16; len -= 16, ksaddr8 += 16, udaddr8 += 16) { 243 __builtin_prefetch(ksaddr8 + 16, 0, 1); 244 copyout_16uint8s(ksaddr8, udaddr8, ds_msr); 245 } 246 247 while (len-- > 0) { 248 copyout_uint8(udaddr8++, *ksaddr8++, ds_msr); 249 } 250 } 251 252 static inline void 253 copyout_uint32s(vaddr_t ksaddr, vaddr_t udaddr, size_t len, register_t ds_msr) 254 { 255 const size_t line_size = curcpu()->ci_ci.dcache_line_size; 256 const size_t line_mask = line_size - 1; 257 const size_t udalignment = udaddr & line_mask; 258 KASSERT((ksaddr & 3) == 0); 259 KASSERT((udaddr & 3) == 0); 260 const uint32_t *ksaddr32 = (void *)ksaddr; 261 uint32_t *udaddr32 = (void *)udaddr; 262 len >>= 2; 263 __builtin_prefetch(ksaddr32, 0, 1); 264 if (udalignment != 0 && udalignment + 4*len > line_size) { 265 size_t slen = (line_size - udalignment) >> 2; 266 len -= slen; 267 for (; slen >= 8; ksaddr32 += 8, udaddr32 += 8, slen -= 8) { 268 copyout_8uint32s(ksaddr32, udaddr32, ds_msr, line_mask); 269 } 270 while (slen-- > 0) { 271 copyout_uint32(udaddr32++, *ksaddr32++, ds_msr); 272 } 273 if (len == 0) 274 return; 275 } 276 __builtin_prefetch(ksaddr32, 0, 1); 277 while (len >= 16) { 278 __builtin_prefetch(ksaddr32 + 8, 0, 1); 279 __builtin_prefetch(ksaddr32 + 16, 0, 1); 280 copyout_16uint32s(ksaddr32, udaddr32, ds_msr, line_mask); 281 ksaddr32 += 16, udaddr32 += 16, len -= 16; 282 } 283 KASSERT(len <= 16); 284 if (len >= 8) { 285 __builtin_prefetch(ksaddr32 + 8, 0, 1); 286 copyout_8uint32s(ksaddr32, udaddr32, ds_msr, line_mask); 287 ksaddr32 += 8, udaddr32 += 8, len -= 8; 288 } 289 while (len-- > 0) { 290 copyout_uint32(udaddr32++, *ksaddr32++, ds_msr); 291 } 292 } 293 294 int 295 copyout(const void *vksaddr, void *vudaddr, size_t len) 296 { 297 struct pcb * const pcb = lwp_getpcb(curlwp); 298 struct faultbuf env; 299 vaddr_t udaddr = (vaddr_t) vudaddr; 300 vaddr_t ksaddr = (vaddr_t) vksaddr; 301 302 if (__predict_false(len == 0)) { 303 return 0; 304 } 305 306 const register_t ds_msr = mfmsr() | PSL_DS; 307 308 int rv = setfault(&env); 309 if (rv != 0) { 310 pcb->pcb_onfault = NULL; 311 return rv; 312 } 313 314 if (__predict_false(len < 4)) { 315 copyout_uint8s(ksaddr, udaddr, len, ds_msr); 316 pcb->pcb_onfault = NULL; 317 return 0; 318 } 319 320 const size_t alignment = (udaddr ^ ksaddr) & 3; 321 if (__predict_true(alignment == 0)) { 322 size_t slen; 323 if (__predict_false(ksaddr & 3)) { 324 slen = 4 - (ksaddr & 3); 325 copyout_uint8s(ksaddr, udaddr, slen, ds_msr); 326 udaddr += slen, ksaddr += slen, len -= slen; 327 } 328 slen = len & ~3; 329 if (__predict_true(slen >= 4)) { 330 copyout_uint32s(ksaddr, udaddr, slen, ds_msr); 331 udaddr += slen, ksaddr += slen, len -= slen; 332 } 333 } 334 335 if (len > 0) { 336 copyout_uint8s(ksaddr, udaddr, len, ds_msr); 337 } 338 pcb->pcb_onfault = NULL; 339 return 0; 340 } 341 342 int 343 copyoutstr(const void *ksaddr, void *udaddr, size_t len, size_t *lenp) 344 { 345 struct pcb * const pcb = lwp_getpcb(curlwp); 346 struct faultbuf env; 347 348 if (__predict_false(len == 0)) { 349 if (lenp) 350 *lenp = 0; 351 return 0; 352 } 353 354 if (setfault(&env)) { 355 pcb->pcb_onfault = NULL; 356 if (lenp) 357 *lenp = 0; 358 return EFAULT; 359 } 360 361 const register_t ds_msr = mfmsr() | PSL_DS; 362 const uint8_t *ksaddr8 = ksaddr; 363 size_t copylen = 0; 364 365 #if 1 366 uint8_t *udaddr8 = (void *)udaddr; 367 368 while (copylen++ < len) { 369 const uint8_t data = *ksaddr8++; 370 copyout_uint8(udaddr8++, data, ds_msr); 371 if (data == 0) 372 break; 373 } 374 #else 375 uint32_t *udaddr32 = (void *)((uintptr_t)udaddr & ~3); 376 377 size_t boff = (uintptr_t)udaddr & 3; 378 bool done = false; 379 size_t wlen = 0; 380 size_t data = 0; 381 382 /* 383 * If the destination buffer doesn't start on a 32-bit boundary 384 * try to partially fill in the first word. If we succeed we can 385 * finish writing it while preserving the bytes on front. 386 */ 387 if (boff > 0) { 388 KASSERT(len > 0); 389 do { 390 data = (data << 8) | *ksaddr8++; 391 wlen++; 392 done = ((uint8_t)data == 0 || len == wlen); 393 } while (!done && boff + wlen < 4); 394 KASSERT(wlen > 0); 395 data <<= 8 * boff; 396 if (!done || boff + wlen == 4) { 397 uint32_t mask = 0xffffffff << (8 * boff); 398 copyout_le32_with_mask(udaddr32++, data, mask, ds_msr); 399 boff = 0; 400 copylen = wlen; 401 wlen = 0; 402 data = 0; 403 } 404 } 405 406 /* 407 * Now we get to the heart of the routine. Build up complete words 408 * if possible. When we have one, write it to the user's address 409 * space and go for the next. If we ran out of space or we found the 410 * end of the string, stop building. If we managed to build a complete 411 * word, just write it and be happy. Otherwise we have to deal with 412 * the trailing bytes. 413 */ 414 KASSERT(done || boff == 0); 415 KASSERT(done || copylen < len); 416 while (!done) { 417 KASSERT(wlen == 0); 418 KASSERT(copylen < len); 419 do { 420 data = (data << 8) | *ksaddr8++; 421 wlen++; 422 done = ((uint8_t)data == 0 || copylen + wlen == len); 423 } while (!done && wlen < 4); 424 KASSERT(done || wlen == 4); 425 if (__predict_true(wlen == 4)) { 426 copyout_le32(udaddr32++, data, ds_msr); 427 data = 0; 428 copylen += wlen; 429 wlen = 0; 430 KASSERT(copylen < len || done); 431 } 432 } 433 KASSERT(wlen < 3); 434 if (wlen) { 435 /* 436 * Remember even though we are running big-endian we are using 437 * byte reversed load/stores so we need to deal with things as 438 * little endian. 439 * 440 * wlen=1 boff=0: 441 * (~(~0 << 8) << 0) -> (~(0xffffff00) << 0) -> 0x000000ff 442 * wlen=1 boff=1: 443 * (~(~0 << 8) << 8) -> (~(0xffffff00) << 8) -> 0x0000ff00 444 * wlen=1 boff=2: 445 * (~(~0 << 8) << 16) -> (~(0xffffff00) << 16) -> 0x00ff0000 446 * wlen=1 boff=3: 447 * (~(~0 << 8) << 24) -> (~(0xffffff00) << 24) -> 0xff000000 448 * wlen=2 boff=0: 449 * (~(~0 << 16) << 0) -> (~(0xffff0000) << 0) -> 0x0000ffff 450 * wlen=2 boff=1: 451 * (~(~0 << 16) << 8) -> (~(0xffff0000) << 8) -> 0x00ffff00 452 * wlen=2 boff=2: 453 * (~(~0 << 16) << 16) -> (~(0xffff0000) << 16) -> 0xffff0000 454 * wlen=3 boff=0: 455 * (~(~0 << 24) << 0) -> (~(0xff000000) << 0) -> 0x00ffffff 456 * wlen=3 boff=1: 457 * (~(~0 << 24) << 8) -> (~(0xff000000) << 8) -> 0xffffff00 458 */ 459 KASSERT(boff + wlen <= 4); 460 uint32_t mask = (~(~0 << (8 * wlen))) << (8 * boff); 461 KASSERT(mask != 0xffffffff); 462 copyout_le32_with_mask(udaddr32, data, mask, ds_msr); 463 copylen += wlen; 464 } 465 #endif 466 467 pcb->pcb_onfault = NULL; 468 if (lenp) 469 *lenp = copylen; 470 return 0; 471 } 472