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 unpin_user_pages_dirty_lock(&page, 1, umem->writable && dirty); 58 } 59 60 sg_free_table(&umem->sg_head); 61 } 62 63 /* ib_umem_add_sg_table - Add N contiguous pages to scatter table 64 * 65 * sg: current scatterlist entry 66 * page_list: array of npage struct page pointers 67 * npages: number of pages in page_list 68 * max_seg_sz: maximum segment size in bytes 69 * nents: [out] number of entries in the scatterlist 70 * 71 * Return new end of scatterlist 72 */ 73 static struct scatterlist *ib_umem_add_sg_table(struct scatterlist *sg, 74 struct page **page_list, 75 unsigned long npages, 76 unsigned int max_seg_sz, 77 int *nents) 78 { 79 unsigned long first_pfn; 80 unsigned long i = 0; 81 bool update_cur_sg = false; 82 bool first = !sg_page(sg); 83 84 /* Check if new page_list is contiguous with end of previous page_list. 85 * sg->length here is a multiple of PAGE_SIZE and sg->offset is 0. 86 */ 87 if (!first && (page_to_pfn(sg_page(sg)) + (sg->length >> PAGE_SHIFT) == 88 page_to_pfn(page_list[0]))) 89 update_cur_sg = true; 90 91 while (i != npages) { 92 unsigned long len; 93 struct page *first_page = page_list[i]; 94 95 first_pfn = page_to_pfn(first_page); 96 97 /* Compute the number of contiguous pages we have starting 98 * at i 99 */ 100 for (len = 0; i != npages && 101 first_pfn + len == page_to_pfn(page_list[i]) && 102 len < (max_seg_sz >> PAGE_SHIFT); 103 len++) 104 i++; 105 106 /* Squash N contiguous pages from page_list into current sge */ 107 if (update_cur_sg) { 108 if ((max_seg_sz - sg->length) >= (len << PAGE_SHIFT)) { 109 sg_set_page(sg, sg_page(sg), 110 sg->length + (len << PAGE_SHIFT), 111 0); 112 update_cur_sg = false; 113 continue; 114 } 115 update_cur_sg = false; 116 } 117 118 /* Squash N contiguous pages into next sge or first sge */ 119 if (!first) 120 sg = sg_next(sg); 121 122 (*nents)++; 123 sg_set_page(sg, first_page, len << PAGE_SHIFT, 0); 124 first = false; 125 } 126 127 return sg; 128 } 129 130 /** 131 * ib_umem_find_best_pgsz - Find best HW page size to use for this MR 132 * 133 * @umem: umem struct 134 * @pgsz_bitmap: bitmap of HW supported page sizes 135 * @virt: IOVA 136 * 137 * This helper is intended for HW that support multiple page 138 * sizes but can do only a single page size in an MR. 139 * 140 * Returns 0 if the umem requires page sizes not supported by 141 * the driver to be mapped. Drivers always supporting PAGE_SIZE 142 * or smaller will never see a 0 result. 143 */ 144 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem, 145 unsigned long pgsz_bitmap, 146 unsigned long virt) 147 { 148 struct scatterlist *sg; 149 unsigned int best_pg_bit; 150 unsigned long va, pgoff; 151 dma_addr_t mask; 152 int i; 153 154 /* At minimum, drivers must support PAGE_SIZE or smaller */ 155 if (WARN_ON(!(pgsz_bitmap & GENMASK(PAGE_SHIFT, 0)))) 156 return 0; 157 158 va = virt; 159 /* max page size not to exceed MR length */ 160 mask = roundup_pow_of_two(umem->length); 161 /* offset into first SGL */ 162 pgoff = umem->address & ~PAGE_MASK; 163 164 for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) { 165 /* Walk SGL and reduce max page size if VA/PA bits differ 166 * for any address. 167 */ 168 mask |= (sg_dma_address(sg) + pgoff) ^ va; 169 va += sg_dma_len(sg) - pgoff; 170 /* Except for the last entry, the ending iova alignment sets 171 * the maximum possible page size as the low bits of the iova 172 * must be zero when starting the next chunk. 173 */ 174 if (i != (umem->nmap - 1)) 175 mask |= va; 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 * @device: IB device to connect UMEM 188 * @addr: userspace virtual address to start at 189 * @size: length of region to pin 190 * @access: IB_ACCESS_xxx flags for memory being pinned 191 */ 192 struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, 193 size_t size, int access) 194 { 195 struct ib_umem *umem; 196 struct page **page_list; 197 unsigned long lock_limit; 198 unsigned long new_pinned; 199 unsigned long cur_base; 200 struct mm_struct *mm; 201 unsigned long npages; 202 int ret; 203 struct scatterlist *sg; 204 unsigned int gup_flags = FOLL_WRITE; 205 206 /* 207 * If the combination of the addr and size requested for this memory 208 * region causes an integer overflow, return error. 209 */ 210 if (((addr + size) < addr) || 211 PAGE_ALIGN(addr + size) < (addr + size)) 212 return ERR_PTR(-EINVAL); 213 214 if (!can_do_mlock()) 215 return ERR_PTR(-EPERM); 216 217 if (access & IB_ACCESS_ON_DEMAND) 218 return ERR_PTR(-EOPNOTSUPP); 219 220 umem = kzalloc(sizeof(*umem), GFP_KERNEL); 221 if (!umem) 222 return ERR_PTR(-ENOMEM); 223 umem->ibdev = device; 224 umem->length = size; 225 umem->address = addr; 226 umem->writable = ib_access_writable(access); 227 umem->owning_mm = mm = current->mm; 228 mmgrab(mm); 229 230 page_list = (struct page **) __get_free_page(GFP_KERNEL); 231 if (!page_list) { 232 ret = -ENOMEM; 233 goto umem_kfree; 234 } 235 236 npages = ib_umem_num_pages(umem); 237 if (npages == 0 || npages > UINT_MAX) { 238 ret = -EINVAL; 239 goto out; 240 } 241 242 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 243 244 new_pinned = atomic64_add_return(npages, &mm->pinned_vm); 245 if (new_pinned > lock_limit && !capable(CAP_IPC_LOCK)) { 246 atomic64_sub(npages, &mm->pinned_vm); 247 ret = -ENOMEM; 248 goto out; 249 } 250 251 cur_base = addr & PAGE_MASK; 252 253 ret = sg_alloc_table(&umem->sg_head, npages, GFP_KERNEL); 254 if (ret) 255 goto vma; 256 257 if (!umem->writable) 258 gup_flags |= FOLL_FORCE; 259 260 sg = umem->sg_head.sgl; 261 262 while (npages) { 263 ret = pin_user_pages_fast(cur_base, 264 min_t(unsigned long, npages, 265 PAGE_SIZE / 266 sizeof(struct page *)), 267 gup_flags | FOLL_LONGTERM, page_list); 268 if (ret < 0) 269 goto umem_release; 270 271 cur_base += ret * PAGE_SIZE; 272 npages -= ret; 273 274 sg = ib_umem_add_sg_table(sg, page_list, ret, 275 dma_get_max_seg_size(device->dma_device), 276 &umem->sg_nents); 277 } 278 279 sg_mark_end(sg); 280 281 umem->nmap = ib_dma_map_sg(device, 282 umem->sg_head.sgl, 283 umem->sg_nents, 284 DMA_BIDIRECTIONAL); 285 286 if (!umem->nmap) { 287 ret = -ENOMEM; 288 goto umem_release; 289 } 290 291 ret = 0; 292 goto out; 293 294 umem_release: 295 __ib_umem_release(device, umem, 0); 296 vma: 297 atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm); 298 out: 299 free_page((unsigned long) page_list); 300 umem_kfree: 301 if (ret) { 302 mmdrop(umem->owning_mm); 303 kfree(umem); 304 } 305 return ret ? ERR_PTR(ret) : umem; 306 } 307 EXPORT_SYMBOL(ib_umem_get); 308 309 /** 310 * ib_umem_release - release memory pinned with ib_umem_get 311 * @umem: umem struct to release 312 */ 313 void ib_umem_release(struct ib_umem *umem) 314 { 315 if (!umem) 316 return; 317 if (umem->is_odp) 318 return ib_umem_odp_release(to_ib_umem_odp(umem)); 319 320 __ib_umem_release(umem->ibdev, umem, 1); 321 322 atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm); 323 mmdrop(umem->owning_mm); 324 kfree(umem); 325 } 326 EXPORT_SYMBOL(ib_umem_release); 327 328 int ib_umem_page_count(struct ib_umem *umem) 329 { 330 int i, n = 0; 331 struct scatterlist *sg; 332 333 for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) 334 n += sg_dma_len(sg) >> PAGE_SHIFT; 335 336 return n; 337 } 338 EXPORT_SYMBOL(ib_umem_page_count); 339 340 /* 341 * Copy from the given ib_umem's pages to the given buffer. 342 * 343 * umem - the umem to copy from 344 * offset - offset to start copying from 345 * dst - destination buffer 346 * length - buffer length 347 * 348 * Returns 0 on success, or an error code. 349 */ 350 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, 351 size_t length) 352 { 353 size_t end = offset + length; 354 int ret; 355 356 if (offset > umem->length || length > umem->length - offset) { 357 pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n", 358 offset, umem->length, end); 359 return -EINVAL; 360 } 361 362 ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->sg_nents, dst, length, 363 offset + ib_umem_offset(umem)); 364 365 if (ret < 0) 366 return ret; 367 else if (ret != length) 368 return -EINVAL; 369 else 370 return 0; 371 } 372 EXPORT_SYMBOL(ib_umem_copy_from); 373