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 (!PageDirty(page) && umem->writable && dirty) 58 set_page_dirty_lock(page); 59 put_page(page); 60 } 61 62 sg_free_table(&umem->sg_head); 63 } 64 65 /* ib_umem_add_sg_table - Add N contiguous pages to scatter table 66 * 67 * sg: current scatterlist entry 68 * page_list: array of npage struct page pointers 69 * npages: number of pages in page_list 70 * max_seg_sz: maximum segment size in bytes 71 * nents: [out] number of entries in the scatterlist 72 * 73 * Return new end of scatterlist 74 */ 75 static struct scatterlist *ib_umem_add_sg_table(struct scatterlist *sg, 76 struct page **page_list, 77 unsigned long npages, 78 unsigned int max_seg_sz, 79 int *nents) 80 { 81 unsigned long first_pfn; 82 unsigned long i = 0; 83 bool update_cur_sg = false; 84 bool first = !sg_page(sg); 85 86 /* Check if new page_list is contiguous with end of previous page_list. 87 * sg->length here is a multiple of PAGE_SIZE and sg->offset is 0. 88 */ 89 if (!first && (page_to_pfn(sg_page(sg)) + (sg->length >> PAGE_SHIFT) == 90 page_to_pfn(page_list[0]))) 91 update_cur_sg = true; 92 93 while (i != npages) { 94 unsigned long len; 95 struct page *first_page = page_list[i]; 96 97 first_pfn = page_to_pfn(first_page); 98 99 /* Compute the number of contiguous pages we have starting 100 * at i 101 */ 102 for (len = 0; i != npages && 103 first_pfn + len == page_to_pfn(page_list[i]) && 104 len < (max_seg_sz >> PAGE_SHIFT); 105 len++) 106 i++; 107 108 /* Squash N contiguous pages from page_list into current sge */ 109 if (update_cur_sg) { 110 if ((max_seg_sz - sg->length) >= (len << PAGE_SHIFT)) { 111 sg_set_page(sg, sg_page(sg), 112 sg->length + (len << PAGE_SHIFT), 113 0); 114 update_cur_sg = false; 115 continue; 116 } 117 update_cur_sg = false; 118 } 119 120 /* Squash N contiguous pages into next sge or first sge */ 121 if (!first) 122 sg = sg_next(sg); 123 124 (*nents)++; 125 sg_set_page(sg, first_page, len << PAGE_SHIFT, 0); 126 first = false; 127 } 128 129 return sg; 130 } 131 132 /** 133 * ib_umem_find_best_pgsz - Find best HW page size to use for this MR 134 * 135 * @umem: umem struct 136 * @pgsz_bitmap: bitmap of HW supported page sizes 137 * @virt: IOVA 138 * 139 * This helper is intended for HW that support multiple page 140 * sizes but can do only a single page size in an MR. 141 * 142 * Returns 0 if the umem requires page sizes not supported by 143 * the driver to be mapped. Drivers always supporting PAGE_SIZE 144 * or smaller will never see a 0 result. 145 */ 146 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem, 147 unsigned long pgsz_bitmap, 148 unsigned long virt) 149 { 150 struct scatterlist *sg; 151 unsigned int best_pg_bit; 152 unsigned long va, pgoff; 153 dma_addr_t mask; 154 int i; 155 156 /* At minimum, drivers must support PAGE_SIZE or smaller */ 157 if (WARN_ON(!(pgsz_bitmap & GENMASK(PAGE_SHIFT, 0)))) 158 return 0; 159 160 va = virt; 161 /* max page size not to exceed MR length */ 162 mask = roundup_pow_of_two(umem->length); 163 /* offset into first SGL */ 164 pgoff = umem->address & ~PAGE_MASK; 165 166 for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) { 167 /* Walk SGL and reduce max page size if VA/PA bits differ 168 * for any address. 169 */ 170 mask |= (sg_dma_address(sg) + pgoff) ^ va; 171 if (i && i != (umem->nmap - 1)) 172 /* restrict by length as well for interior SGEs */ 173 mask |= sg_dma_len(sg); 174 va += sg_dma_len(sg) - pgoff; 175 pgoff = 0; 176 } 177 best_pg_bit = rdma_find_pg_bit(mask, pgsz_bitmap); 178 179 return BIT_ULL(best_pg_bit); 180 } 181 EXPORT_SYMBOL(ib_umem_find_best_pgsz); 182 183 /** 184 * ib_umem_get - Pin and DMA map userspace memory. 185 * 186 * If access flags indicate ODP memory, avoid pinning. Instead, stores 187 * the mm for future page fault handling in conjunction with MMU notifiers. 188 * 189 * @udata: userspace context to pin memory for 190 * @addr: userspace virtual address to start at 191 * @size: length of region to pin 192 * @access: IB_ACCESS_xxx flags for memory being pinned 193 * @dmasync: flush in-flight DMA when the memory region is written 194 */ 195 struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr, 196 size_t size, int access, int dmasync) 197 { 198 struct ib_ucontext *context; 199 struct ib_umem *umem; 200 struct page **page_list; 201 unsigned long lock_limit; 202 unsigned long new_pinned; 203 unsigned long cur_base; 204 struct mm_struct *mm; 205 unsigned long npages; 206 int ret; 207 unsigned long dma_attrs = 0; 208 struct scatterlist *sg; 209 unsigned int gup_flags = FOLL_WRITE; 210 211 if (!udata) 212 return ERR_PTR(-EIO); 213 214 context = container_of(udata, struct uverbs_attr_bundle, driver_udata) 215 ->context; 216 if (!context) 217 return ERR_PTR(-EIO); 218 219 if (dmasync) 220 dma_attrs |= DMA_ATTR_WRITE_BARRIER; 221 222 /* 223 * If the combination of the addr and size requested for this memory 224 * region causes an integer overflow, return error. 225 */ 226 if (((addr + size) < addr) || 227 PAGE_ALIGN(addr + size) < (addr + size)) 228 return ERR_PTR(-EINVAL); 229 230 if (!can_do_mlock()) 231 return ERR_PTR(-EPERM); 232 233 if (access & IB_ACCESS_ON_DEMAND) { 234 umem = kzalloc(sizeof(struct ib_umem_odp), GFP_KERNEL); 235 if (!umem) 236 return ERR_PTR(-ENOMEM); 237 umem->is_odp = 1; 238 } else { 239 umem = kzalloc(sizeof(*umem), GFP_KERNEL); 240 if (!umem) 241 return ERR_PTR(-ENOMEM); 242 } 243 244 umem->context = context; 245 umem->length = size; 246 umem->address = addr; 247 umem->page_shift = PAGE_SHIFT; 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->is_odp) { 365 ib_umem_odp_release(to_ib_umem_odp(umem)); 366 __ib_umem_release_tail(umem); 367 return; 368 } 369 370 __ib_umem_release(umem->context->device, umem, 1); 371 372 atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm); 373 __ib_umem_release_tail(umem); 374 } 375 EXPORT_SYMBOL(ib_umem_release); 376 377 int ib_umem_page_count(struct ib_umem *umem) 378 { 379 int i; 380 int n; 381 struct scatterlist *sg; 382 383 if (umem->is_odp) 384 return ib_umem_num_pages(umem); 385 386 n = 0; 387 for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) 388 n += sg_dma_len(sg) >> umem->page_shift; 389 390 return n; 391 } 392 EXPORT_SYMBOL(ib_umem_page_count); 393 394 /* 395 * Copy from the given ib_umem's pages to the given buffer. 396 * 397 * umem - the umem to copy from 398 * offset - offset to start copying from 399 * dst - destination buffer 400 * length - buffer length 401 * 402 * Returns 0 on success, or an error code. 403 */ 404 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, 405 size_t length) 406 { 407 size_t end = offset + length; 408 int ret; 409 410 if (offset > umem->length || length > umem->length - offset) { 411 pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n", 412 offset, umem->length, end); 413 return -EINVAL; 414 } 415 416 ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->sg_nents, dst, length, 417 offset + ib_umem_offset(umem)); 418 419 if (ret < 0) 420 return ret; 421 else if (ret != length) 422 return -EINVAL; 423 else 424 return 0; 425 } 426 EXPORT_SYMBOL(ib_umem_copy_from); 427