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 _LINUXKPI_LINUX_SCATTERLIST_H_ 34 #define _LINUXKPI_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 #define for_each_sgtable_sg(sgt, sg, i) \ 103 for_each_sg((sgt)->sgl, sg, (sgt)->orig_nents, i) 104 105 #define for_each_sgtable_page(sgt, iter, pgoffset) \ 106 for_each_sg_page((sgt)->sgl, iter, (sgt)->orig_nents, pgoffset) 107 108 #define for_each_sgtable_dma_sg(sgt, sg, iter) \ 109 for_each_sg((sgt)->sgl, sg, (sgt)->nents, iter) 110 111 #define for_each_sgtable_dma_page(sgt, iter, pgoffset) \ 112 for_each_sg_dma_page((sgt)->sgl, iter, (sgt)->nents, pgoffset) 113 114 typedef struct scatterlist *(sg_alloc_fn) (unsigned int, gfp_t); 115 typedef void (sg_free_fn) (struct scatterlist *, unsigned int); 116 117 static inline void 118 sg_assign_page(struct scatterlist *sg, struct page *page) 119 { 120 unsigned long page_link = sg->page_link & SG_PAGE_LINK_MASK; 121 122 sg->page_link = page_link | (unsigned long)page; 123 } 124 125 static inline void 126 sg_set_page(struct scatterlist *sg, struct page *page, unsigned int len, 127 unsigned int offset) 128 { 129 sg_assign_page(sg, page); 130 sg->offset = offset; 131 sg->length = len; 132 } 133 134 static inline struct page * 135 sg_page(struct scatterlist *sg) 136 { 137 return ((struct page *)((sg)->page_link & ~SG_PAGE_LINK_MASK)); 138 } 139 140 static inline void 141 sg_set_buf(struct scatterlist *sg, const void *buf, unsigned int buflen) 142 { 143 sg_set_page(sg, virt_to_page(buf), buflen, 144 ((uintptr_t)buf) & (PAGE_SIZE - 1)); 145 } 146 147 static inline struct scatterlist * 148 sg_next(struct scatterlist *sg) 149 { 150 if (sg_is_last(sg)) 151 return (NULL); 152 sg++; 153 if (sg_is_chain(sg)) 154 sg = sg_chain_ptr(sg); 155 return (sg); 156 } 157 158 static inline vm_paddr_t 159 sg_phys(struct scatterlist *sg) 160 { 161 return (VM_PAGE_TO_PHYS(sg_page(sg)) + sg->offset); 162 } 163 164 static inline void * 165 sg_virt(struct scatterlist *sg) 166 { 167 168 return ((void *)((unsigned long)page_address(sg_page(sg)) + sg->offset)); 169 } 170 171 static inline void 172 sg_chain(struct scatterlist *prv, unsigned int prv_nents, 173 struct scatterlist *sgl) 174 { 175 struct scatterlist *sg = &prv[prv_nents - 1]; 176 177 sg->offset = 0; 178 sg->length = 0; 179 sg->page_link = ((unsigned long)sgl | 180 SG_PAGE_LINK_CHAIN) & ~SG_PAGE_LINK_LAST; 181 } 182 183 static inline void 184 sg_mark_end(struct scatterlist *sg) 185 { 186 sg->page_link |= SG_PAGE_LINK_LAST; 187 sg->page_link &= ~SG_PAGE_LINK_CHAIN; 188 } 189 190 static inline void 191 sg_init_table(struct scatterlist *sg, unsigned int nents) 192 { 193 bzero(sg, sizeof(*sg) * nents); 194 sg_mark_end(&sg[nents - 1]); 195 } 196 197 static inline void 198 sg_init_one(struct scatterlist *sg, const void *buf, unsigned int buflen) 199 { 200 sg_init_table(sg, 1); 201 sg_set_buf(sg, buf, buflen); 202 } 203 204 static struct scatterlist * 205 sg_kmalloc(unsigned int nents, gfp_t gfp_mask) 206 { 207 if (nents == SG_MAX_SINGLE_ALLOC) { 208 return ((void *)__get_free_page(gfp_mask)); 209 } else 210 return (kmalloc(nents * sizeof(struct scatterlist), gfp_mask)); 211 } 212 213 static inline void 214 sg_kfree(struct scatterlist *sg, unsigned int nents) 215 { 216 if (nents == SG_MAX_SINGLE_ALLOC) { 217 free_page((unsigned long)sg); 218 } else 219 kfree(sg); 220 } 221 222 static inline void 223 __sg_free_table(struct sg_table *table, unsigned int max_ents, 224 bool skip_first_chunk, sg_free_fn * free_fn) 225 { 226 struct scatterlist *sgl, *next; 227 228 if (unlikely(!table->sgl)) 229 return; 230 231 sgl = table->sgl; 232 while (table->orig_nents) { 233 unsigned int alloc_size = table->orig_nents; 234 unsigned int sg_size; 235 236 if (alloc_size > max_ents) { 237 next = sg_chain_ptr(&sgl[max_ents - 1]); 238 alloc_size = max_ents; 239 sg_size = alloc_size - 1; 240 } else { 241 sg_size = alloc_size; 242 next = NULL; 243 } 244 245 table->orig_nents -= sg_size; 246 if (skip_first_chunk) 247 skip_first_chunk = 0; 248 else 249 free_fn(sgl, alloc_size); 250 sgl = next; 251 } 252 253 table->sgl = NULL; 254 } 255 256 static inline void 257 sg_free_table(struct sg_table *table) 258 { 259 __sg_free_table(table, SG_MAX_SINGLE_ALLOC, 0, sg_kfree); 260 } 261 262 static inline int 263 __sg_alloc_table(struct sg_table *table, unsigned int nents, 264 unsigned int max_ents, struct scatterlist *first_chunk, 265 gfp_t gfp_mask, sg_alloc_fn *alloc_fn) 266 { 267 struct scatterlist *sg, *prv; 268 unsigned int left; 269 270 memset(table, 0, sizeof(*table)); 271 272 if (nents == 0) 273 return (-EINVAL); 274 left = nents; 275 prv = NULL; 276 do { 277 unsigned int sg_size; 278 unsigned int alloc_size = left; 279 280 if (alloc_size > max_ents) { 281 alloc_size = max_ents; 282 sg_size = alloc_size - 1; 283 } else 284 sg_size = alloc_size; 285 286 left -= sg_size; 287 288 if (first_chunk) { 289 sg = first_chunk; 290 first_chunk = NULL; 291 } else { 292 sg = alloc_fn(alloc_size, gfp_mask); 293 } 294 if (unlikely(!sg)) { 295 if (prv) 296 table->nents = ++table->orig_nents; 297 298 return (-ENOMEM); 299 } 300 sg_init_table(sg, alloc_size); 301 table->nents = table->orig_nents += sg_size; 302 303 if (prv) 304 sg_chain(prv, max_ents, sg); 305 else 306 table->sgl = sg; 307 308 if (!left) 309 sg_mark_end(&sg[sg_size - 1]); 310 311 prv = sg; 312 } while (left); 313 314 return (0); 315 } 316 317 static inline int 318 sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask) 319 { 320 int ret; 321 322 ret = __sg_alloc_table(table, nents, SG_MAX_SINGLE_ALLOC, 323 NULL, gfp_mask, sg_kmalloc); 324 if (unlikely(ret)) 325 __sg_free_table(table, SG_MAX_SINGLE_ALLOC, 0, sg_kfree); 326 327 return (ret); 328 } 329 330 static inline int 331 __sg_alloc_table_from_pages(struct sg_table *sgt, 332 struct page **pages, unsigned int count, 333 unsigned long off, unsigned long size, 334 unsigned int max_segment, gfp_t gfp_mask) 335 { 336 unsigned int i, segs, cur, len; 337 int rc; 338 struct scatterlist *s; 339 340 if (__predict_false(!max_segment || offset_in_page(max_segment))) 341 return (-EINVAL); 342 343 len = 0; 344 for (segs = i = 1; i < count; ++i) { 345 len += PAGE_SIZE; 346 if (len >= max_segment || 347 page_to_pfn(pages[i]) != page_to_pfn(pages[i - 1]) + 1) { 348 ++segs; 349 len = 0; 350 } 351 } 352 if (__predict_false((rc = sg_alloc_table(sgt, segs, gfp_mask)))) 353 return (rc); 354 355 cur = 0; 356 for_each_sg(sgt->sgl, s, sgt->orig_nents, i) { 357 unsigned long seg_size; 358 unsigned int j; 359 360 len = 0; 361 for (j = cur + 1; j < count; ++j) { 362 len += PAGE_SIZE; 363 if (len >= max_segment || page_to_pfn(pages[j]) != 364 page_to_pfn(pages[j - 1]) + 1) 365 break; 366 } 367 368 seg_size = ((j - cur) << PAGE_SHIFT) - off; 369 sg_set_page(s, pages[cur], MIN(size, seg_size), off); 370 size -= seg_size; 371 off = 0; 372 cur = j; 373 } 374 return (0); 375 } 376 377 static inline int 378 sg_alloc_table_from_pages(struct sg_table *sgt, 379 struct page **pages, unsigned int count, 380 unsigned long off, unsigned long size, 381 gfp_t gfp_mask) 382 { 383 384 return (__sg_alloc_table_from_pages(sgt, pages, count, off, size, 385 SCATTERLIST_MAX_SEGMENT, gfp_mask)); 386 } 387 388 static inline int 389 sg_nents(struct scatterlist *sg) 390 { 391 int nents; 392 393 for (nents = 0; sg; sg = sg_next(sg)) 394 nents++; 395 return (nents); 396 } 397 398 static inline void 399 __sg_page_iter_start(struct sg_page_iter *piter, 400 struct scatterlist *sglist, unsigned int nents, 401 unsigned long pgoffset) 402 { 403 piter->internal.pg_advance = 0; 404 piter->internal.nents = nents; 405 406 piter->sg = sglist; 407 piter->sg_pgoffset = pgoffset; 408 } 409 410 static inline void 411 _sg_iter_next(struct sg_page_iter *iter) 412 { 413 struct scatterlist *sg; 414 unsigned int pgcount; 415 416 sg = iter->sg; 417 pgcount = (sg->offset + sg->length + PAGE_SIZE - 1) >> PAGE_SHIFT; 418 419 ++iter->sg_pgoffset; 420 while (iter->sg_pgoffset >= pgcount) { 421 iter->sg_pgoffset -= pgcount; 422 sg = sg_next(sg); 423 --iter->maxents; 424 if (sg == NULL || iter->maxents == 0) 425 break; 426 pgcount = (sg->offset + sg->length + PAGE_SIZE - 1) >> PAGE_SHIFT; 427 } 428 iter->sg = sg; 429 } 430 431 static inline int 432 sg_page_count(struct scatterlist *sg) 433 { 434 return (PAGE_ALIGN(sg->offset + sg->length) >> PAGE_SHIFT); 435 } 436 #define sg_dma_page_count(sg) \ 437 sg_page_count(sg) 438 439 static inline bool 440 __sg_page_iter_next(struct sg_page_iter *piter) 441 { 442 unsigned int pgcount; 443 444 if (piter->internal.nents == 0) 445 return (0); 446 if (piter->sg == NULL) 447 return (0); 448 449 piter->sg_pgoffset += piter->internal.pg_advance; 450 piter->internal.pg_advance = 1; 451 452 while (1) { 453 pgcount = sg_page_count(piter->sg); 454 if (likely(piter->sg_pgoffset < pgcount)) 455 break; 456 piter->sg_pgoffset -= pgcount; 457 piter->sg = sg_next(piter->sg); 458 if (--piter->internal.nents == 0) 459 return (0); 460 if (piter->sg == NULL) 461 return (0); 462 } 463 return (1); 464 } 465 #define __sg_page_iter_dma_next(itr) \ 466 __sg_page_iter_next(&(itr)->base) 467 468 static inline void 469 _sg_iter_init(struct scatterlist *sgl, struct sg_page_iter *iter, 470 unsigned int nents, unsigned long pgoffset) 471 { 472 if (nents) { 473 iter->sg = sgl; 474 iter->sg_pgoffset = pgoffset - 1; 475 iter->maxents = nents; 476 _sg_iter_next(iter); 477 } else { 478 iter->sg = NULL; 479 iter->sg_pgoffset = 0; 480 iter->maxents = 0; 481 } 482 } 483 484 /* 485 * sg_page_iter_dma_address() is implemented as a macro because it 486 * needs to accept two different and identical structure types. This 487 * allows both old and new code to co-exist. The compile time assert 488 * adds some safety, that the structure sizes match. 489 */ 490 #define sg_page_iter_dma_address(spi) ({ \ 491 struct sg_page_iter *__spi = (void *)(spi); \ 492 dma_addr_t __dma_address; \ 493 CTASSERT(sizeof(*(spi)) == sizeof(*__spi)); \ 494 __dma_address = __spi->sg->dma_address + \ 495 (__spi->sg_pgoffset << PAGE_SHIFT); \ 496 __dma_address; \ 497 }) 498 499 static inline struct page * 500 sg_page_iter_page(struct sg_page_iter *piter) 501 { 502 return (nth_page(sg_page(piter->sg), piter->sg_pgoffset)); 503 } 504 505 static __inline size_t 506 sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents, 507 const void *buf, size_t buflen, off_t skip) 508 { 509 struct sg_page_iter piter; 510 struct page *page; 511 struct sf_buf *sf; 512 size_t len, copied; 513 char *p, *b; 514 515 if (buflen == 0) 516 return (0); 517 518 b = __DECONST(char *, buf); 519 copied = 0; 520 sched_pin(); 521 for_each_sg_page(sgl, &piter, nents, 0) { 522 523 /* Skip to the start. */ 524 if (piter.sg->length <= skip) { 525 skip -= piter.sg->length; 526 continue; 527 } 528 529 /* See how much to copy. */ 530 KASSERT(((piter.sg->length - skip) != 0 && (buflen != 0)), 531 ("%s: sg len %u - skip %ju || buflen %zu is 0\n", 532 __func__, piter.sg->length, (uintmax_t)skip, buflen)); 533 len = min(piter.sg->length - skip, buflen); 534 535 page = sg_page_iter_page(&piter); 536 sf = sf_buf_alloc(page, SFB_CPUPRIVATE | SFB_NOWAIT); 537 if (sf == NULL) 538 break; 539 p = (char *)sf_buf_kva(sf) + piter.sg_pgoffset + skip; 540 memcpy(p, b, len); 541 sf_buf_free(sf); 542 543 /* We copied so nothing more to skip. */ 544 skip = 0; 545 copied += len; 546 /* Either we exactly filled the page, or we are done. */ 547 buflen -= len; 548 if (buflen == 0) 549 break; 550 b += len; 551 } 552 sched_unpin(); 553 554 return (copied); 555 } 556 557 static inline size_t 558 sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents, 559 const void *buf, size_t buflen) 560 { 561 return (sg_pcopy_from_buffer(sgl, nents, buf, buflen, 0)); 562 } 563 564 static inline size_t 565 sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents, 566 void *buf, size_t buflen, off_t offset) 567 { 568 struct sg_page_iter iter; 569 struct scatterlist *sg; 570 struct page *page; 571 struct sf_buf *sf; 572 char *vaddr; 573 size_t total = 0; 574 size_t len; 575 576 if (!PMAP_HAS_DMAP) 577 sched_pin(); 578 for_each_sg_page(sgl, &iter, nents, 0) { 579 sg = iter.sg; 580 581 if (offset >= sg->length) { 582 offset -= sg->length; 583 continue; 584 } 585 len = ulmin(buflen, sg->length - offset); 586 if (len == 0) 587 break; 588 589 page = sg_page_iter_page(&iter); 590 if (!PMAP_HAS_DMAP) { 591 sf = sf_buf_alloc(page, SFB_CPUPRIVATE | SFB_NOWAIT); 592 if (sf == NULL) 593 break; 594 vaddr = (char *)sf_buf_kva(sf); 595 } else 596 vaddr = (char *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(page)); 597 memcpy(buf, vaddr + sg->offset + offset, len); 598 if (!PMAP_HAS_DMAP) 599 sf_buf_free(sf); 600 601 /* start at beginning of next page */ 602 offset = 0; 603 604 /* advance buffer */ 605 buf = (char *)buf + len; 606 buflen -= len; 607 total += len; 608 } 609 if (!PMAP_HAS_DMAP) 610 sched_unpin(); 611 return (total); 612 } 613 614 #endif /* _LINUXKPI_LINUX_SCATTERLIST_H_ */ 615