1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013-2017 Mellanox Technologies, Ltd. 6 * Copyright (c) 2015 Matthew Dillon <dillon@backplane.com> 7 * Copyright (c) 2016 Matthew Macy 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice unmodified, this list of conditions, and the following 15 * disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 * 31 * $FreeBSD$ 32 */ 33 #ifndef _LINUX_SCATTERLIST_H_ 34 #define _LINUX_SCATTERLIST_H_ 35 36 #include <sys/types.h> 37 #include <sys/sf_buf.h> 38 39 #include <linux/page.h> 40 #include <linux/slab.h> 41 #include <linux/mm.h> 42 43 struct bus_dmamap; 44 struct scatterlist { 45 unsigned long page_link; 46 #define SG_PAGE_LINK_CHAIN 0x1UL 47 #define SG_PAGE_LINK_LAST 0x2UL 48 #define SG_PAGE_LINK_MASK 0x3UL 49 unsigned int offset; 50 unsigned int length; 51 dma_addr_t dma_address; 52 struct bus_dmamap *dma_map; /* FreeBSD specific */ 53 }; 54 55 CTASSERT((sizeof(struct scatterlist) & SG_PAGE_LINK_MASK) == 0); 56 57 struct sg_table { 58 struct scatterlist *sgl; 59 unsigned int nents; 60 unsigned int orig_nents; 61 }; 62 63 struct sg_page_iter { 64 struct scatterlist *sg; 65 unsigned int sg_pgoffset; 66 unsigned int maxents; 67 struct { 68 unsigned int nents; 69 int pg_advance; 70 } internal; 71 }; 72 73 struct sg_dma_page_iter { 74 struct sg_page_iter base; 75 }; 76 77 #define SCATTERLIST_MAX_SEGMENT (-1U & ~(PAGE_SIZE - 1)) 78 79 #define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist)) 80 81 #define SG_MAGIC 0x87654321UL 82 #define SG_CHAIN SG_PAGE_LINK_CHAIN 83 #define SG_END SG_PAGE_LINK_LAST 84 85 #define sg_is_chain(sg) ((sg)->page_link & SG_PAGE_LINK_CHAIN) 86 #define sg_is_last(sg) ((sg)->page_link & SG_PAGE_LINK_LAST) 87 #define sg_chain_ptr(sg) \ 88 ((struct scatterlist *) ((sg)->page_link & ~SG_PAGE_LINK_MASK)) 89 90 #define sg_dma_address(sg) (sg)->dma_address 91 #define sg_dma_len(sg) (sg)->length 92 93 #define for_each_sg_page(sgl, iter, nents, pgoffset) \ 94 for (_sg_iter_init(sgl, iter, nents, pgoffset); \ 95 (iter)->sg; _sg_iter_next(iter)) 96 #define for_each_sg_dma_page(sgl, iter, nents, pgoffset) \ 97 for_each_sg_page(sgl, &(iter)->base, nents, pgoffset) 98 99 #define for_each_sg(sglist, sg, sgmax, iter) \ 100 for (iter = 0, sg = (sglist); iter < (sgmax); iter++, sg = sg_next(sg)) 101 102 typedef struct scatterlist *(sg_alloc_fn) (unsigned int, gfp_t); 103 typedef void (sg_free_fn) (struct scatterlist *, unsigned int); 104 105 static inline void 106 sg_assign_page(struct scatterlist *sg, struct page *page) 107 { 108 unsigned long page_link = sg->page_link & SG_PAGE_LINK_MASK; 109 110 sg->page_link = page_link | (unsigned long)page; 111 } 112 113 static inline void 114 sg_set_page(struct scatterlist *sg, struct page *page, unsigned int len, 115 unsigned int offset) 116 { 117 sg_assign_page(sg, page); 118 sg->offset = offset; 119 sg->length = len; 120 } 121 122 static inline struct page * 123 sg_page(struct scatterlist *sg) 124 { 125 return ((struct page *)((sg)->page_link & ~SG_PAGE_LINK_MASK)); 126 } 127 128 static inline void 129 sg_set_buf(struct scatterlist *sg, const void *buf, unsigned int buflen) 130 { 131 sg_set_page(sg, virt_to_page(buf), buflen, 132 ((uintptr_t)buf) & (PAGE_SIZE - 1)); 133 } 134 135 static inline struct scatterlist * 136 sg_next(struct scatterlist *sg) 137 { 138 if (sg_is_last(sg)) 139 return (NULL); 140 sg++; 141 if (sg_is_chain(sg)) 142 sg = sg_chain_ptr(sg); 143 return (sg); 144 } 145 146 static inline vm_paddr_t 147 sg_phys(struct scatterlist *sg) 148 { 149 return (VM_PAGE_TO_PHYS(sg_page(sg)) + sg->offset); 150 } 151 152 static inline void * 153 sg_virt(struct scatterlist *sg) 154 { 155 156 return ((void *)((unsigned long)page_address(sg_page(sg)) + sg->offset)); 157 } 158 159 static inline void 160 sg_chain(struct scatterlist *prv, unsigned int prv_nents, 161 struct scatterlist *sgl) 162 { 163 struct scatterlist *sg = &prv[prv_nents - 1]; 164 165 sg->offset = 0; 166 sg->length = 0; 167 sg->page_link = ((unsigned long)sgl | 168 SG_PAGE_LINK_CHAIN) & ~SG_PAGE_LINK_LAST; 169 } 170 171 static inline void 172 sg_mark_end(struct scatterlist *sg) 173 { 174 sg->page_link |= SG_PAGE_LINK_LAST; 175 sg->page_link &= ~SG_PAGE_LINK_CHAIN; 176 } 177 178 static inline void 179 sg_init_table(struct scatterlist *sg, unsigned int nents) 180 { 181 bzero(sg, sizeof(*sg) * nents); 182 sg_mark_end(&sg[nents - 1]); 183 } 184 185 static inline void 186 sg_init_one(struct scatterlist *sg, const void *buf, unsigned int buflen) 187 { 188 sg_init_table(sg, 1); 189 sg_set_buf(sg, buf, buflen); 190 } 191 192 static struct scatterlist * 193 sg_kmalloc(unsigned int nents, gfp_t gfp_mask) 194 { 195 if (nents == SG_MAX_SINGLE_ALLOC) { 196 return ((void *)__get_free_page(gfp_mask)); 197 } else 198 return (kmalloc(nents * sizeof(struct scatterlist), gfp_mask)); 199 } 200 201 static inline void 202 sg_kfree(struct scatterlist *sg, unsigned int nents) 203 { 204 if (nents == SG_MAX_SINGLE_ALLOC) { 205 free_page((unsigned long)sg); 206 } else 207 kfree(sg); 208 } 209 210 static inline void 211 __sg_free_table(struct sg_table *table, unsigned int max_ents, 212 bool skip_first_chunk, sg_free_fn * free_fn) 213 { 214 struct scatterlist *sgl, *next; 215 216 if (unlikely(!table->sgl)) 217 return; 218 219 sgl = table->sgl; 220 while (table->orig_nents) { 221 unsigned int alloc_size = table->orig_nents; 222 unsigned int sg_size; 223 224 if (alloc_size > max_ents) { 225 next = sg_chain_ptr(&sgl[max_ents - 1]); 226 alloc_size = max_ents; 227 sg_size = alloc_size - 1; 228 } else { 229 sg_size = alloc_size; 230 next = NULL; 231 } 232 233 table->orig_nents -= sg_size; 234 if (skip_first_chunk) 235 skip_first_chunk = 0; 236 else 237 free_fn(sgl, alloc_size); 238 sgl = next; 239 } 240 241 table->sgl = NULL; 242 } 243 244 static inline void 245 sg_free_table(struct sg_table *table) 246 { 247 __sg_free_table(table, SG_MAX_SINGLE_ALLOC, 0, sg_kfree); 248 } 249 250 static inline int 251 __sg_alloc_table(struct sg_table *table, unsigned int nents, 252 unsigned int max_ents, struct scatterlist *first_chunk, 253 gfp_t gfp_mask, sg_alloc_fn *alloc_fn) 254 { 255 struct scatterlist *sg, *prv; 256 unsigned int left; 257 258 memset(table, 0, sizeof(*table)); 259 260 if (nents == 0) 261 return (-EINVAL); 262 left = nents; 263 prv = NULL; 264 do { 265 unsigned int sg_size; 266 unsigned int alloc_size = left; 267 268 if (alloc_size > max_ents) { 269 alloc_size = max_ents; 270 sg_size = alloc_size - 1; 271 } else 272 sg_size = alloc_size; 273 274 left -= sg_size; 275 276 if (first_chunk) { 277 sg = first_chunk; 278 first_chunk = NULL; 279 } else { 280 sg = alloc_fn(alloc_size, gfp_mask); 281 } 282 if (unlikely(!sg)) { 283 if (prv) 284 table->nents = ++table->orig_nents; 285 286 return (-ENOMEM); 287 } 288 sg_init_table(sg, alloc_size); 289 table->nents = table->orig_nents += sg_size; 290 291 if (prv) 292 sg_chain(prv, max_ents, sg); 293 else 294 table->sgl = sg; 295 296 if (!left) 297 sg_mark_end(&sg[sg_size - 1]); 298 299 prv = sg; 300 } while (left); 301 302 return (0); 303 } 304 305 static inline int 306 sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask) 307 { 308 int ret; 309 310 ret = __sg_alloc_table(table, nents, SG_MAX_SINGLE_ALLOC, 311 NULL, gfp_mask, sg_kmalloc); 312 if (unlikely(ret)) 313 __sg_free_table(table, SG_MAX_SINGLE_ALLOC, 0, sg_kfree); 314 315 return (ret); 316 } 317 318 static inline int 319 __sg_alloc_table_from_pages(struct sg_table *sgt, 320 struct page **pages, unsigned int count, 321 unsigned long off, unsigned long size, 322 unsigned int max_segment, gfp_t gfp_mask) 323 { 324 unsigned int i, segs, cur, len; 325 int rc; 326 struct scatterlist *s; 327 328 if (__predict_false(!max_segment || offset_in_page(max_segment))) 329 return (-EINVAL); 330 331 len = 0; 332 for (segs = i = 1; i < count; ++i) { 333 len += PAGE_SIZE; 334 if (len >= max_segment || 335 page_to_pfn(pages[i]) != page_to_pfn(pages[i - 1]) + 1) { 336 ++segs; 337 len = 0; 338 } 339 } 340 if (__predict_false((rc = sg_alloc_table(sgt, segs, gfp_mask)))) 341 return (rc); 342 343 cur = 0; 344 for_each_sg(sgt->sgl, s, sgt->orig_nents, i) { 345 unsigned long seg_size; 346 unsigned int j; 347 348 len = 0; 349 for (j = cur + 1; j < count; ++j) { 350 len += PAGE_SIZE; 351 if (len >= max_segment || page_to_pfn(pages[j]) != 352 page_to_pfn(pages[j - 1]) + 1) 353 break; 354 } 355 356 seg_size = ((j - cur) << PAGE_SHIFT) - off; 357 sg_set_page(s, pages[cur], MIN(size, seg_size), off); 358 size -= seg_size; 359 off = 0; 360 cur = j; 361 } 362 return (0); 363 } 364 365 static inline int 366 sg_alloc_table_from_pages(struct sg_table *sgt, 367 struct page **pages, unsigned int count, 368 unsigned long off, unsigned long size, 369 gfp_t gfp_mask) 370 { 371 372 return (__sg_alloc_table_from_pages(sgt, pages, count, off, size, 373 SCATTERLIST_MAX_SEGMENT, gfp_mask)); 374 } 375 376 static inline int 377 sg_nents(struct scatterlist *sg) 378 { 379 int nents; 380 381 for (nents = 0; sg; sg = sg_next(sg)) 382 nents++; 383 return (nents); 384 } 385 386 static inline void 387 __sg_page_iter_start(struct sg_page_iter *piter, 388 struct scatterlist *sglist, unsigned int nents, 389 unsigned long pgoffset) 390 { 391 piter->internal.pg_advance = 0; 392 piter->internal.nents = nents; 393 394 piter->sg = sglist; 395 piter->sg_pgoffset = pgoffset; 396 } 397 398 static inline void 399 _sg_iter_next(struct sg_page_iter *iter) 400 { 401 struct scatterlist *sg; 402 unsigned int pgcount; 403 404 sg = iter->sg; 405 pgcount = (sg->offset + sg->length + PAGE_SIZE - 1) >> PAGE_SHIFT; 406 407 ++iter->sg_pgoffset; 408 while (iter->sg_pgoffset >= pgcount) { 409 iter->sg_pgoffset -= pgcount; 410 sg = sg_next(sg); 411 --iter->maxents; 412 if (sg == NULL || iter->maxents == 0) 413 break; 414 pgcount = (sg->offset + sg->length + PAGE_SIZE - 1) >> PAGE_SHIFT; 415 } 416 iter->sg = sg; 417 } 418 419 static inline int 420 sg_page_count(struct scatterlist *sg) 421 { 422 return (PAGE_ALIGN(sg->offset + sg->length) >> PAGE_SHIFT); 423 } 424 #define sg_dma_page_count(sg) \ 425 sg_page_count(sg) 426 427 static inline bool 428 __sg_page_iter_next(struct sg_page_iter *piter) 429 { 430 unsigned int pgcount; 431 432 if (piter->internal.nents == 0) 433 return (0); 434 if (piter->sg == NULL) 435 return (0); 436 437 piter->sg_pgoffset += piter->internal.pg_advance; 438 piter->internal.pg_advance = 1; 439 440 while (1) { 441 pgcount = sg_page_count(piter->sg); 442 if (likely(piter->sg_pgoffset < pgcount)) 443 break; 444 piter->sg_pgoffset -= pgcount; 445 piter->sg = sg_next(piter->sg); 446 if (--piter->internal.nents == 0) 447 return (0); 448 if (piter->sg == NULL) 449 return (0); 450 } 451 return (1); 452 } 453 #define __sg_page_iter_dma_next(itr) \ 454 __sg_page_iter_next(&(itr)->base) 455 456 static inline void 457 _sg_iter_init(struct scatterlist *sgl, struct sg_page_iter *iter, 458 unsigned int nents, unsigned long pgoffset) 459 { 460 if (nents) { 461 iter->sg = sgl; 462 iter->sg_pgoffset = pgoffset - 1; 463 iter->maxents = nents; 464 _sg_iter_next(iter); 465 } else { 466 iter->sg = NULL; 467 iter->sg_pgoffset = 0; 468 iter->maxents = 0; 469 } 470 } 471 472 /* 473 * sg_page_iter_dma_address() is implemented as a macro because it 474 * needs to accept two different and identical structure types. This 475 * allows both old and new code to co-exist. The compile time assert 476 * adds some safety, that the structure sizes match. 477 */ 478 #define sg_page_iter_dma_address(spi) ({ \ 479 struct sg_page_iter *__spi = (void *)(spi); \ 480 dma_addr_t __dma_address; \ 481 CTASSERT(sizeof(*(spi)) == sizeof(*__spi)); \ 482 __dma_address = __spi->sg->dma_address + \ 483 (__spi->sg_pgoffset << PAGE_SHIFT); \ 484 __dma_address; \ 485 }) 486 487 static inline struct page * 488 sg_page_iter_page(struct sg_page_iter *piter) 489 { 490 return (nth_page(sg_page(piter->sg), piter->sg_pgoffset)); 491 } 492 493 static __inline size_t 494 sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents, 495 const void *buf, size_t buflen, off_t skip) 496 { 497 struct sg_page_iter piter; 498 struct page *page; 499 struct sf_buf *sf; 500 size_t len, copied; 501 char *p, *b; 502 503 if (buflen == 0) 504 return (0); 505 506 b = __DECONST(char *, buf); 507 copied = 0; 508 sched_pin(); 509 for_each_sg_page(sgl, &piter, nents, 0) { 510 511 /* Skip to the start. */ 512 if (piter.sg->length <= skip) { 513 skip -= piter.sg->length; 514 continue; 515 } 516 517 /* See how much to copy. */ 518 KASSERT(((piter.sg->length - skip) != 0 && (buflen != 0)), 519 ("%s: sg len %u - skip %ju || buflen %zu is 0\n", 520 __func__, piter.sg->length, (uintmax_t)skip, buflen)); 521 len = min(piter.sg->length - skip, buflen); 522 523 page = sg_page_iter_page(&piter); 524 sf = sf_buf_alloc(page, SFB_CPUPRIVATE | SFB_NOWAIT); 525 if (sf == NULL) 526 break; 527 p = (char *)sf_buf_kva(sf) + piter.sg_pgoffset + skip; 528 memcpy(p, b, len); 529 sf_buf_free(sf); 530 531 /* We copied so nothing more to skip. */ 532 skip = 0; 533 copied += len; 534 /* Either we exactly filled the page, or we are done. */ 535 buflen -= len; 536 if (buflen == 0) 537 break; 538 b += len; 539 } 540 sched_unpin(); 541 542 return (copied); 543 } 544 545 static inline size_t 546 sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents, 547 const void *buf, size_t buflen) 548 { 549 return (sg_pcopy_from_buffer(sgl, nents, buf, buflen, 0)); 550 } 551 552 static inline size_t 553 sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents, 554 void *buf, size_t buflen, off_t offset) 555 { 556 struct sg_page_iter iter; 557 struct scatterlist *sg; 558 struct page *page; 559 struct sf_buf *sf; 560 char *vaddr; 561 size_t total = 0; 562 size_t len; 563 564 if (!PMAP_HAS_DMAP) 565 sched_pin(); 566 for_each_sg_page(sgl, &iter, nents, 0) { 567 sg = iter.sg; 568 569 if (offset >= sg->length) { 570 offset -= sg->length; 571 continue; 572 } 573 len = ulmin(buflen, sg->length - offset); 574 if (len == 0) 575 break; 576 577 page = sg_page_iter_page(&iter); 578 if (!PMAP_HAS_DMAP) { 579 sf = sf_buf_alloc(page, SFB_CPUPRIVATE | SFB_NOWAIT); 580 if (sf == NULL) 581 break; 582 vaddr = (char *)sf_buf_kva(sf); 583 } else 584 vaddr = (char *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(page)); 585 memcpy(buf, vaddr + sg->offset + offset, len); 586 if (!PMAP_HAS_DMAP) 587 sf_buf_free(sf); 588 589 /* start at beginning of next page */ 590 offset = 0; 591 592 /* advance buffer */ 593 buf = (char *)buf + len; 594 buflen -= len; 595 total += len; 596 } 597 if (!PMAP_HAS_DMAP) 598 sched_unpin(); 599 return (total); 600 } 601 602 #endif /* _LINUX_SCATTERLIST_H_ */ 603