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 <linux/count_zeros.h> 43 #include <rdma/ib_umem_odp.h> 44 45 #include "uverbs.h" 46 47 static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty) 48 { 49 struct sg_page_iter sg_iter; 50 struct page *page; 51 52 if (umem->nmap > 0) 53 ib_dma_unmap_sg(dev, umem->sg_head.sgl, umem->sg_nents, 54 DMA_BIDIRECTIONAL); 55 56 for_each_sg_page(umem->sg_head.sgl, &sg_iter, umem->sg_nents, 0) { 57 page = sg_page_iter_page(&sg_iter); 58 unpin_user_pages_dirty_lock(&page, 1, umem->writable && dirty); 59 } 60 61 sg_free_table(&umem->sg_head); 62 } 63 64 /** 65 * ib_umem_find_best_pgsz - Find best HW page size to use for this MR 66 * 67 * @umem: umem struct 68 * @pgsz_bitmap: bitmap of HW supported page sizes 69 * @virt: IOVA 70 * 71 * This helper is intended for HW that support multiple page 72 * sizes but can do only a single page size in an MR. 73 * 74 * Returns 0 if the umem requires page sizes not supported by 75 * the driver to be mapped. Drivers always supporting PAGE_SIZE 76 * or smaller will never see a 0 result. 77 */ 78 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem, 79 unsigned long pgsz_bitmap, 80 unsigned long virt) 81 { 82 struct scatterlist *sg; 83 unsigned long va, pgoff; 84 dma_addr_t mask; 85 int i; 86 87 if (umem->is_odp) { 88 unsigned int page_size = BIT(to_ib_umem_odp(umem)->page_shift); 89 90 /* ODP must always be self consistent. */ 91 if (!(pgsz_bitmap & page_size)) 92 return 0; 93 return page_size; 94 } 95 96 /* rdma_for_each_block() has a bug if the page size is smaller than the 97 * page size used to build the umem. For now prevent smaller page sizes 98 * from being returned. 99 */ 100 pgsz_bitmap &= GENMASK(BITS_PER_LONG - 1, PAGE_SHIFT); 101 102 /* At minimum, drivers must support PAGE_SIZE or smaller */ 103 if (WARN_ON(!(pgsz_bitmap & GENMASK(PAGE_SHIFT, 0)))) 104 return 0; 105 106 umem->iova = va = virt; 107 /* The best result is the smallest page size that results in the minimum 108 * number of required pages. Compute the largest page size that could 109 * work based on VA address bits that don't change. 110 */ 111 mask = pgsz_bitmap & 112 GENMASK(BITS_PER_LONG - 1, 113 bits_per((umem->length - 1 + virt) ^ virt)); 114 /* offset into first SGL */ 115 pgoff = umem->address & ~PAGE_MASK; 116 117 for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) { 118 /* Walk SGL and reduce max page size if VA/PA bits differ 119 * for any address. 120 */ 121 mask |= (sg_dma_address(sg) + pgoff) ^ va; 122 va += sg_dma_len(sg) - pgoff; 123 /* Except for the last entry, the ending iova alignment sets 124 * the maximum possible page size as the low bits of the iova 125 * must be zero when starting the next chunk. 126 */ 127 if (i != (umem->nmap - 1)) 128 mask |= va; 129 pgoff = 0; 130 } 131 132 /* The mask accumulates 1's in each position where the VA and physical 133 * address differ, thus the length of trailing 0 is the largest page 134 * size that can pass the VA through to the physical. 135 */ 136 if (mask) 137 pgsz_bitmap &= GENMASK(count_trailing_zeros(mask), 0); 138 return rounddown_pow_of_two(pgsz_bitmap); 139 } 140 EXPORT_SYMBOL(ib_umem_find_best_pgsz); 141 142 /** 143 * ib_umem_get - Pin and DMA map userspace memory. 144 * 145 * @device: IB device to connect UMEM 146 * @addr: userspace virtual address to start at 147 * @size: length of region to pin 148 * @access: IB_ACCESS_xxx flags for memory being pinned 149 */ 150 struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, 151 size_t size, int access) 152 { 153 struct ib_umem *umem; 154 struct page **page_list; 155 unsigned long lock_limit; 156 unsigned long new_pinned; 157 unsigned long cur_base; 158 unsigned long dma_attr = 0; 159 struct mm_struct *mm; 160 unsigned long npages; 161 int ret; 162 struct scatterlist *sg = NULL; 163 unsigned int gup_flags = FOLL_WRITE; 164 165 /* 166 * If the combination of the addr and size requested for this memory 167 * region causes an integer overflow, return error. 168 */ 169 if (((addr + size) < addr) || 170 PAGE_ALIGN(addr + size) < (addr + size)) 171 return ERR_PTR(-EINVAL); 172 173 if (!can_do_mlock()) 174 return ERR_PTR(-EPERM); 175 176 if (access & IB_ACCESS_ON_DEMAND) 177 return ERR_PTR(-EOPNOTSUPP); 178 179 umem = kzalloc(sizeof(*umem), GFP_KERNEL); 180 if (!umem) 181 return ERR_PTR(-ENOMEM); 182 umem->ibdev = device; 183 umem->length = size; 184 umem->address = addr; 185 /* 186 * Drivers should call ib_umem_find_best_pgsz() to set the iova 187 * correctly. 188 */ 189 umem->iova = addr; 190 umem->writable = ib_access_writable(access); 191 umem->owning_mm = mm = current->mm; 192 mmgrab(mm); 193 194 page_list = (struct page **) __get_free_page(GFP_KERNEL); 195 if (!page_list) { 196 ret = -ENOMEM; 197 goto umem_kfree; 198 } 199 200 npages = ib_umem_num_pages(umem); 201 if (npages == 0 || npages > UINT_MAX) { 202 ret = -EINVAL; 203 goto out; 204 } 205 206 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 207 208 new_pinned = atomic64_add_return(npages, &mm->pinned_vm); 209 if (new_pinned > lock_limit && !capable(CAP_IPC_LOCK)) { 210 atomic64_sub(npages, &mm->pinned_vm); 211 ret = -ENOMEM; 212 goto out; 213 } 214 215 cur_base = addr & PAGE_MASK; 216 217 if (!umem->writable) 218 gup_flags |= FOLL_FORCE; 219 220 while (npages) { 221 cond_resched(); 222 ret = pin_user_pages_fast(cur_base, 223 min_t(unsigned long, npages, 224 PAGE_SIZE / 225 sizeof(struct page *)), 226 gup_flags | FOLL_LONGTERM, page_list); 227 if (ret < 0) 228 goto umem_release; 229 230 cur_base += ret * PAGE_SIZE; 231 npages -= ret; 232 sg = __sg_alloc_table_from_pages(&umem->sg_head, page_list, ret, 233 0, ret << PAGE_SHIFT, 234 ib_dma_max_seg_size(device), sg, npages, 235 GFP_KERNEL); 236 umem->sg_nents = umem->sg_head.nents; 237 if (IS_ERR(sg)) { 238 unpin_user_pages_dirty_lock(page_list, ret, 0); 239 ret = PTR_ERR(sg); 240 goto umem_release; 241 } 242 } 243 244 if (access & IB_ACCESS_RELAXED_ORDERING) 245 dma_attr |= DMA_ATTR_WEAK_ORDERING; 246 247 umem->nmap = 248 ib_dma_map_sg_attrs(device, umem->sg_head.sgl, umem->sg_nents, 249 DMA_BIDIRECTIONAL, dma_attr); 250 251 if (!umem->nmap) { 252 ret = -ENOMEM; 253 goto umem_release; 254 } 255 256 ret = 0; 257 goto out; 258 259 umem_release: 260 __ib_umem_release(device, umem, 0); 261 atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm); 262 out: 263 free_page((unsigned long) page_list); 264 umem_kfree: 265 if (ret) { 266 mmdrop(umem->owning_mm); 267 kfree(umem); 268 } 269 return ret ? ERR_PTR(ret) : umem; 270 } 271 EXPORT_SYMBOL(ib_umem_get); 272 273 /** 274 * ib_umem_release - release memory pinned with ib_umem_get 275 * @umem: umem struct to release 276 */ 277 void ib_umem_release(struct ib_umem *umem) 278 { 279 if (!umem) 280 return; 281 if (umem->is_odp) 282 return ib_umem_odp_release(to_ib_umem_odp(umem)); 283 284 __ib_umem_release(umem->ibdev, umem, 1); 285 286 atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm); 287 mmdrop(umem->owning_mm); 288 kfree(umem); 289 } 290 EXPORT_SYMBOL(ib_umem_release); 291 292 /* 293 * Copy from the given ib_umem's pages to the given buffer. 294 * 295 * umem - the umem to copy from 296 * offset - offset to start copying from 297 * dst - destination buffer 298 * length - buffer length 299 * 300 * Returns 0 on success, or an error code. 301 */ 302 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, 303 size_t length) 304 { 305 size_t end = offset + length; 306 int ret; 307 308 if (offset > umem->length || length > umem->length - offset) { 309 pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n", 310 offset, umem->length, end); 311 return -EINVAL; 312 } 313 314 ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->sg_nents, dst, length, 315 offset + ib_umem_offset(umem)); 316 317 if (ret < 0) 318 return ret; 319 else if (ret != length) 320 return -EINVAL; 321 else 322 return 0; 323 } 324 EXPORT_SYMBOL(ib_umem_copy_from); 325