1 /* 2 * Copyright (c) 2005 Topspin Communications. All rights reserved. 3 * Copyright (c) 2005 Cisco Systems. All rights reserved. 4 * Copyright (c) 2005 Mellanox Technologies. All rights reserved. 5 * 6 * This software is available to you under a choice of one of two 7 * licenses. You may choose to be licensed under the terms of the GNU 8 * General Public License (GPL) Version 2, available from the file 9 * COPYING in the main directory of this source tree, or the 10 * OpenIB.org BSD license below: 11 * 12 * Redistribution and use in source and binary forms, with or 13 * without modification, are permitted provided that the following 14 * conditions are met: 15 * 16 * - Redistributions of source code must retain the above 17 * copyright notice, this list of conditions and the following 18 * disclaimer. 19 * 20 * - Redistributions in binary form must reproduce the above 21 * copyright notice, this list of conditions and the following 22 * disclaimer in the documentation and/or other materials 23 * provided with the distribution. 24 * 25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 26 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 27 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 28 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 29 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 30 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 31 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 32 * SOFTWARE. 33 */ 34 35 #include <linux/mm.h> 36 #include <linux/dma-mapping.h> 37 #include <linux/sched/signal.h> 38 #include <linux/sched/mm.h> 39 #include <linux/export.h> 40 #include <linux/slab.h> 41 #include <linux/pagemap.h> 42 #include <rdma/ib_umem_odp.h> 43 44 #include "uverbs.h" 45 46 static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty) 47 { 48 struct sg_page_iter sg_iter; 49 struct page *page; 50 51 if (umem->nmap > 0) 52 ib_dma_unmap_sg(dev, umem->sg_head.sgl, umem->sg_nents, 53 DMA_BIDIRECTIONAL); 54 55 for_each_sg_page(umem->sg_head.sgl, &sg_iter, umem->sg_nents, 0) { 56 page = sg_page_iter_page(&sg_iter); 57 if (umem->writable && dirty) 58 put_user_pages_dirty_lock(&page, 1); 59 else 60 put_user_page(page); 61 } 62 63 sg_free_table(&umem->sg_head); 64 } 65 66 /* ib_umem_add_sg_table - Add N contiguous pages to scatter table 67 * 68 * sg: current scatterlist entry 69 * page_list: array of npage struct page pointers 70 * npages: number of pages in page_list 71 * max_seg_sz: maximum segment size in bytes 72 * nents: [out] number of entries in the scatterlist 73 * 74 * Return new end of scatterlist 75 */ 76 static struct scatterlist *ib_umem_add_sg_table(struct scatterlist *sg, 77 struct page **page_list, 78 unsigned long npages, 79 unsigned int max_seg_sz, 80 int *nents) 81 { 82 unsigned long first_pfn; 83 unsigned long i = 0; 84 bool update_cur_sg = false; 85 bool first = !sg_page(sg); 86 87 /* Check if new page_list is contiguous with end of previous page_list. 88 * sg->length here is a multiple of PAGE_SIZE and sg->offset is 0. 89 */ 90 if (!first && (page_to_pfn(sg_page(sg)) + (sg->length >> PAGE_SHIFT) == 91 page_to_pfn(page_list[0]))) 92 update_cur_sg = true; 93 94 while (i != npages) { 95 unsigned long len; 96 struct page *first_page = page_list[i]; 97 98 first_pfn = page_to_pfn(first_page); 99 100 /* Compute the number of contiguous pages we have starting 101 * at i 102 */ 103 for (len = 0; i != npages && 104 first_pfn + len == page_to_pfn(page_list[i]) && 105 len < (max_seg_sz >> PAGE_SHIFT); 106 len++) 107 i++; 108 109 /* Squash N contiguous pages from page_list into current sge */ 110 if (update_cur_sg) { 111 if ((max_seg_sz - sg->length) >= (len << PAGE_SHIFT)) { 112 sg_set_page(sg, sg_page(sg), 113 sg->length + (len << PAGE_SHIFT), 114 0); 115 update_cur_sg = false; 116 continue; 117 } 118 update_cur_sg = false; 119 } 120 121 /* Squash N contiguous pages into next sge or first sge */ 122 if (!first) 123 sg = sg_next(sg); 124 125 (*nents)++; 126 sg_set_page(sg, first_page, len << PAGE_SHIFT, 0); 127 first = false; 128 } 129 130 return sg; 131 } 132 133 /** 134 * ib_umem_find_best_pgsz - Find best HW page size to use for this MR 135 * 136 * @umem: umem struct 137 * @pgsz_bitmap: bitmap of HW supported page sizes 138 * @virt: IOVA 139 * 140 * This helper is intended for HW that support multiple page 141 * sizes but can do only a single page size in an MR. 142 * 143 * Returns 0 if the umem requires page sizes not supported by 144 * the driver to be mapped. Drivers always supporting PAGE_SIZE 145 * or smaller will never see a 0 result. 146 */ 147 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem, 148 unsigned long pgsz_bitmap, 149 unsigned long virt) 150 { 151 struct scatterlist *sg; 152 unsigned int best_pg_bit; 153 unsigned long va, pgoff; 154 dma_addr_t mask; 155 int i; 156 157 /* At minimum, drivers must support PAGE_SIZE or smaller */ 158 if (WARN_ON(!(pgsz_bitmap & GENMASK(PAGE_SHIFT, 0)))) 159 return 0; 160 161 va = virt; 162 /* max page size not to exceed MR length */ 163 mask = roundup_pow_of_two(umem->length); 164 /* offset into first SGL */ 165 pgoff = umem->address & ~PAGE_MASK; 166 167 for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) { 168 /* Walk SGL and reduce max page size if VA/PA bits differ 169 * for any address. 170 */ 171 mask |= (sg_dma_address(sg) + pgoff) ^ va; 172 if (i && i != (umem->nmap - 1)) 173 /* restrict by length as well for interior SGEs */ 174 mask |= sg_dma_len(sg); 175 va += sg_dma_len(sg) - pgoff; 176 pgoff = 0; 177 } 178 best_pg_bit = rdma_find_pg_bit(mask, pgsz_bitmap); 179 180 return BIT_ULL(best_pg_bit); 181 } 182 EXPORT_SYMBOL(ib_umem_find_best_pgsz); 183 184 /** 185 * ib_umem_get - Pin and DMA map userspace memory. 186 * 187 * If access flags indicate ODP memory, avoid pinning. Instead, stores 188 * the mm for future page fault handling in conjunction with MMU notifiers. 189 * 190 * @udata: userspace context to pin memory for 191 * @addr: userspace virtual address to start at 192 * @size: length of region to pin 193 * @access: IB_ACCESS_xxx flags for memory being pinned 194 * @dmasync: flush in-flight DMA when the memory region is written 195 */ 196 struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr, 197 size_t size, int access, int dmasync) 198 { 199 struct ib_ucontext *context; 200 struct ib_umem *umem; 201 struct page **page_list; 202 unsigned long lock_limit; 203 unsigned long new_pinned; 204 unsigned long cur_base; 205 struct mm_struct *mm; 206 unsigned long npages; 207 int ret; 208 unsigned long dma_attrs = 0; 209 struct scatterlist *sg; 210 unsigned int gup_flags = FOLL_WRITE; 211 212 if (!udata) 213 return ERR_PTR(-EIO); 214 215 context = container_of(udata, struct uverbs_attr_bundle, driver_udata) 216 ->context; 217 if (!context) 218 return ERR_PTR(-EIO); 219 220 if (dmasync) 221 dma_attrs |= DMA_ATTR_WRITE_BARRIER; 222 223 /* 224 * If the combination of the addr and size requested for this memory 225 * region causes an integer overflow, return error. 226 */ 227 if (((addr + size) < addr) || 228 PAGE_ALIGN(addr + size) < (addr + size)) 229 return ERR_PTR(-EINVAL); 230 231 if (!can_do_mlock()) 232 return ERR_PTR(-EPERM); 233 234 if (access & IB_ACCESS_ON_DEMAND) { 235 umem = kzalloc(sizeof(struct ib_umem_odp), GFP_KERNEL); 236 if (!umem) 237 return ERR_PTR(-ENOMEM); 238 umem->is_odp = 1; 239 } else { 240 umem = kzalloc(sizeof(*umem), GFP_KERNEL); 241 if (!umem) 242 return ERR_PTR(-ENOMEM); 243 } 244 245 umem->context = context; 246 umem->length = size; 247 umem->address = addr; 248 umem->writable = ib_access_writable(access); 249 umem->owning_mm = mm = current->mm; 250 mmgrab(mm); 251 252 if (access & IB_ACCESS_ON_DEMAND) { 253 if (WARN_ON_ONCE(!context->invalidate_range)) { 254 ret = -EINVAL; 255 goto umem_kfree; 256 } 257 258 ret = ib_umem_odp_get(to_ib_umem_odp(umem), access); 259 if (ret) 260 goto umem_kfree; 261 return umem; 262 } 263 264 page_list = (struct page **) __get_free_page(GFP_KERNEL); 265 if (!page_list) { 266 ret = -ENOMEM; 267 goto umem_kfree; 268 } 269 270 npages = ib_umem_num_pages(umem); 271 if (npages == 0 || npages > UINT_MAX) { 272 ret = -EINVAL; 273 goto out; 274 } 275 276 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 277 278 new_pinned = atomic64_add_return(npages, &mm->pinned_vm); 279 if (new_pinned > lock_limit && !capable(CAP_IPC_LOCK)) { 280 atomic64_sub(npages, &mm->pinned_vm); 281 ret = -ENOMEM; 282 goto out; 283 } 284 285 cur_base = addr & PAGE_MASK; 286 287 ret = sg_alloc_table(&umem->sg_head, npages, GFP_KERNEL); 288 if (ret) 289 goto vma; 290 291 if (!umem->writable) 292 gup_flags |= FOLL_FORCE; 293 294 sg = umem->sg_head.sgl; 295 296 while (npages) { 297 down_read(&mm->mmap_sem); 298 ret = get_user_pages(cur_base, 299 min_t(unsigned long, npages, 300 PAGE_SIZE / sizeof (struct page *)), 301 gup_flags | FOLL_LONGTERM, 302 page_list, NULL); 303 if (ret < 0) { 304 up_read(&mm->mmap_sem); 305 goto umem_release; 306 } 307 308 cur_base += ret * PAGE_SIZE; 309 npages -= ret; 310 311 sg = ib_umem_add_sg_table(sg, page_list, ret, 312 dma_get_max_seg_size(context->device->dma_device), 313 &umem->sg_nents); 314 315 up_read(&mm->mmap_sem); 316 } 317 318 sg_mark_end(sg); 319 320 umem->nmap = ib_dma_map_sg_attrs(context->device, 321 umem->sg_head.sgl, 322 umem->sg_nents, 323 DMA_BIDIRECTIONAL, 324 dma_attrs); 325 326 if (!umem->nmap) { 327 ret = -ENOMEM; 328 goto umem_release; 329 } 330 331 ret = 0; 332 goto out; 333 334 umem_release: 335 __ib_umem_release(context->device, umem, 0); 336 vma: 337 atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm); 338 out: 339 free_page((unsigned long) page_list); 340 umem_kfree: 341 if (ret) { 342 mmdrop(umem->owning_mm); 343 kfree(umem); 344 } 345 return ret ? ERR_PTR(ret) : umem; 346 } 347 EXPORT_SYMBOL(ib_umem_get); 348 349 static void __ib_umem_release_tail(struct ib_umem *umem) 350 { 351 mmdrop(umem->owning_mm); 352 if (umem->is_odp) 353 kfree(to_ib_umem_odp(umem)); 354 else 355 kfree(umem); 356 } 357 358 /** 359 * ib_umem_release - release memory pinned with ib_umem_get 360 * @umem: umem struct to release 361 */ 362 void ib_umem_release(struct ib_umem *umem) 363 { 364 if (!umem) 365 return; 366 367 if (umem->is_odp) { 368 ib_umem_odp_release(to_ib_umem_odp(umem)); 369 __ib_umem_release_tail(umem); 370 return; 371 } 372 373 __ib_umem_release(umem->context->device, umem, 1); 374 375 atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm); 376 __ib_umem_release_tail(umem); 377 } 378 EXPORT_SYMBOL(ib_umem_release); 379 380 int ib_umem_page_count(struct ib_umem *umem) 381 { 382 int i; 383 int n; 384 struct scatterlist *sg; 385 386 if (umem->is_odp) 387 return ib_umem_num_pages(umem); 388 389 n = 0; 390 for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) 391 n += sg_dma_len(sg) >> PAGE_SHIFT; 392 393 return n; 394 } 395 EXPORT_SYMBOL(ib_umem_page_count); 396 397 /* 398 * Copy from the given ib_umem's pages to the given buffer. 399 * 400 * umem - the umem to copy from 401 * offset - offset to start copying from 402 * dst - destination buffer 403 * length - buffer length 404 * 405 * Returns 0 on success, or an error code. 406 */ 407 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, 408 size_t length) 409 { 410 size_t end = offset + length; 411 int ret; 412 413 if (offset > umem->length || length > umem->length - offset) { 414 pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n", 415 offset, umem->length, end); 416 return -EINVAL; 417 } 418 419 ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->sg_nents, dst, length, 420 offset + ib_umem_offset(umem)); 421 422 if (ret < 0) 423 return ret; 424 else if (ret != length) 425 return -EINVAL; 426 else 427 return 0; 428 } 429 EXPORT_SYMBOL(ib_umem_copy_from); 430