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 put_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 if (i && i != (umem->nmap - 1)) 170 /* restrict by length as well for interior SGEs */ 171 mask |= sg_dma_len(sg); 172 va += sg_dma_len(sg) - pgoff; 173 pgoff = 0; 174 } 175 best_pg_bit = rdma_find_pg_bit(mask, pgsz_bitmap); 176 177 return BIT_ULL(best_pg_bit); 178 } 179 EXPORT_SYMBOL(ib_umem_find_best_pgsz); 180 181 /** 182 * ib_umem_get - Pin and DMA map userspace memory. 183 * 184 * @udata: userspace context to pin memory for 185 * @addr: userspace virtual address to start at 186 * @size: length of region to pin 187 * @access: IB_ACCESS_xxx flags for memory being pinned 188 * @dmasync: flush in-flight DMA when the memory region is written 189 */ 190 struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr, 191 size_t size, int access, int dmasync) 192 { 193 struct ib_ucontext *context; 194 struct ib_umem *umem; 195 struct page **page_list; 196 unsigned long lock_limit; 197 unsigned long new_pinned; 198 unsigned long cur_base; 199 struct mm_struct *mm; 200 unsigned long npages; 201 int ret; 202 unsigned long dma_attrs = 0; 203 struct scatterlist *sg; 204 unsigned int gup_flags = FOLL_WRITE; 205 206 if (!udata) 207 return ERR_PTR(-EIO); 208 209 context = container_of(udata, struct uverbs_attr_bundle, driver_udata) 210 ->context; 211 if (!context) 212 return ERR_PTR(-EIO); 213 214 if (dmasync) 215 dma_attrs |= DMA_ATTR_WRITE_BARRIER; 216 217 /* 218 * If the combination of the addr and size requested for this memory 219 * region causes an integer overflow, return error. 220 */ 221 if (((addr + size) < addr) || 222 PAGE_ALIGN(addr + size) < (addr + size)) 223 return ERR_PTR(-EINVAL); 224 225 if (!can_do_mlock()) 226 return ERR_PTR(-EPERM); 227 228 if (access & IB_ACCESS_ON_DEMAND) 229 return ERR_PTR(-EOPNOTSUPP); 230 231 umem = kzalloc(sizeof(*umem), GFP_KERNEL); 232 if (!umem) 233 return ERR_PTR(-ENOMEM); 234 umem->ibdev = context->device; 235 umem->length = size; 236 umem->address = addr; 237 umem->writable = ib_access_writable(access); 238 umem->owning_mm = mm = current->mm; 239 mmgrab(mm); 240 241 page_list = (struct page **) __get_free_page(GFP_KERNEL); 242 if (!page_list) { 243 ret = -ENOMEM; 244 goto umem_kfree; 245 } 246 247 npages = ib_umem_num_pages(umem); 248 if (npages == 0 || npages > UINT_MAX) { 249 ret = -EINVAL; 250 goto out; 251 } 252 253 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 254 255 new_pinned = atomic64_add_return(npages, &mm->pinned_vm); 256 if (new_pinned > lock_limit && !capable(CAP_IPC_LOCK)) { 257 atomic64_sub(npages, &mm->pinned_vm); 258 ret = -ENOMEM; 259 goto out; 260 } 261 262 cur_base = addr & PAGE_MASK; 263 264 ret = sg_alloc_table(&umem->sg_head, npages, GFP_KERNEL); 265 if (ret) 266 goto vma; 267 268 if (!umem->writable) 269 gup_flags |= FOLL_FORCE; 270 271 sg = umem->sg_head.sgl; 272 273 while (npages) { 274 down_read(&mm->mmap_sem); 275 ret = get_user_pages(cur_base, 276 min_t(unsigned long, npages, 277 PAGE_SIZE / sizeof (struct page *)), 278 gup_flags | FOLL_LONGTERM, 279 page_list, NULL); 280 if (ret < 0) { 281 up_read(&mm->mmap_sem); 282 goto umem_release; 283 } 284 285 cur_base += ret * PAGE_SIZE; 286 npages -= ret; 287 288 sg = ib_umem_add_sg_table(sg, page_list, ret, 289 dma_get_max_seg_size(context->device->dma_device), 290 &umem->sg_nents); 291 292 up_read(&mm->mmap_sem); 293 } 294 295 sg_mark_end(sg); 296 297 umem->nmap = ib_dma_map_sg_attrs(context->device, 298 umem->sg_head.sgl, 299 umem->sg_nents, 300 DMA_BIDIRECTIONAL, 301 dma_attrs); 302 303 if (!umem->nmap) { 304 ret = -ENOMEM; 305 goto umem_release; 306 } 307 308 ret = 0; 309 goto out; 310 311 umem_release: 312 __ib_umem_release(context->device, umem, 0); 313 vma: 314 atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm); 315 out: 316 free_page((unsigned long) page_list); 317 umem_kfree: 318 if (ret) { 319 mmdrop(umem->owning_mm); 320 kfree(umem); 321 } 322 return ret ? ERR_PTR(ret) : umem; 323 } 324 EXPORT_SYMBOL(ib_umem_get); 325 326 /** 327 * ib_umem_release - release memory pinned with ib_umem_get 328 * @umem: umem struct to release 329 */ 330 void ib_umem_release(struct ib_umem *umem) 331 { 332 if (!umem) 333 return; 334 if (umem->is_odp) 335 return ib_umem_odp_release(to_ib_umem_odp(umem)); 336 337 __ib_umem_release(umem->ibdev, umem, 1); 338 339 atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm); 340 mmdrop(umem->owning_mm); 341 kfree(umem); 342 } 343 EXPORT_SYMBOL(ib_umem_release); 344 345 int ib_umem_page_count(struct ib_umem *umem) 346 { 347 int i, n = 0; 348 struct scatterlist *sg; 349 350 for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) 351 n += sg_dma_len(sg) >> PAGE_SHIFT; 352 353 return n; 354 } 355 EXPORT_SYMBOL(ib_umem_page_count); 356 357 /* 358 * Copy from the given ib_umem's pages to the given buffer. 359 * 360 * umem - the umem to copy from 361 * offset - offset to start copying from 362 * dst - destination buffer 363 * length - buffer length 364 * 365 * Returns 0 on success, or an error code. 366 */ 367 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, 368 size_t length) 369 { 370 size_t end = offset + length; 371 int ret; 372 373 if (offset > umem->length || length > umem->length - offset) { 374 pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n", 375 offset, umem->length, end); 376 return -EINVAL; 377 } 378 379 ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->sg_nents, dst, length, 380 offset + ib_umem_offset(umem)); 381 382 if (ret < 0) 383 return ret; 384 else if (ret != length) 385 return -EINVAL; 386 else 387 return 0; 388 } 389 EXPORT_SYMBOL(ib_umem_copy_from); 390