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 /* rdma_for_each_block() has a bug if the page size is smaller than the 88 * page size used to build the umem. For now prevent smaller page sizes 89 * from being returned. 90 */ 91 pgsz_bitmap &= GENMASK(BITS_PER_LONG - 1, PAGE_SHIFT); 92 93 /* At minimum, drivers must support PAGE_SIZE or smaller */ 94 if (WARN_ON(!(pgsz_bitmap & GENMASK(PAGE_SHIFT, 0)))) 95 return 0; 96 97 umem->iova = va = virt; 98 /* The best result is the smallest page size that results in the minimum 99 * number of required pages. Compute the largest page size that could 100 * work based on VA address bits that don't change. 101 */ 102 mask = pgsz_bitmap & 103 GENMASK(BITS_PER_LONG - 1, 104 bits_per((umem->length - 1 + virt) ^ virt)); 105 /* offset into first SGL */ 106 pgoff = umem->address & ~PAGE_MASK; 107 108 for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) { 109 /* Walk SGL and reduce max page size if VA/PA bits differ 110 * for any address. 111 */ 112 mask |= (sg_dma_address(sg) + pgoff) ^ va; 113 va += sg_dma_len(sg) - pgoff; 114 /* Except for the last entry, the ending iova alignment sets 115 * the maximum possible page size as the low bits of the iova 116 * must be zero when starting the next chunk. 117 */ 118 if (i != (umem->nmap - 1)) 119 mask |= va; 120 pgoff = 0; 121 } 122 123 /* The mask accumulates 1's in each position where the VA and physical 124 * address differ, thus the length of trailing 0 is the largest page 125 * size that can pass the VA through to the physical. 126 */ 127 if (mask) 128 pgsz_bitmap &= GENMASK(count_trailing_zeros(mask), 0); 129 return rounddown_pow_of_two(pgsz_bitmap); 130 } 131 EXPORT_SYMBOL(ib_umem_find_best_pgsz); 132 133 /** 134 * ib_umem_get - Pin and DMA map userspace memory. 135 * 136 * @device: IB device to connect UMEM 137 * @addr: userspace virtual address to start at 138 * @size: length of region to pin 139 * @access: IB_ACCESS_xxx flags for memory being pinned 140 */ 141 struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, 142 size_t size, int access) 143 { 144 struct ib_umem *umem; 145 struct page **page_list; 146 unsigned long lock_limit; 147 unsigned long new_pinned; 148 unsigned long cur_base; 149 unsigned long dma_attr = 0; 150 struct mm_struct *mm; 151 unsigned long npages; 152 int ret; 153 struct scatterlist *sg = NULL; 154 unsigned int gup_flags = FOLL_WRITE; 155 156 /* 157 * If the combination of the addr and size requested for this memory 158 * region causes an integer overflow, return error. 159 */ 160 if (((addr + size) < addr) || 161 PAGE_ALIGN(addr + size) < (addr + size)) 162 return ERR_PTR(-EINVAL); 163 164 if (!can_do_mlock()) 165 return ERR_PTR(-EPERM); 166 167 if (access & IB_ACCESS_ON_DEMAND) 168 return ERR_PTR(-EOPNOTSUPP); 169 170 umem = kzalloc(sizeof(*umem), GFP_KERNEL); 171 if (!umem) 172 return ERR_PTR(-ENOMEM); 173 umem->ibdev = device; 174 umem->length = size; 175 umem->address = addr; 176 /* 177 * Drivers should call ib_umem_find_best_pgsz() to set the iova 178 * correctly. 179 */ 180 umem->iova = addr; 181 umem->writable = ib_access_writable(access); 182 umem->owning_mm = mm = current->mm; 183 mmgrab(mm); 184 185 page_list = (struct page **) __get_free_page(GFP_KERNEL); 186 if (!page_list) { 187 ret = -ENOMEM; 188 goto umem_kfree; 189 } 190 191 npages = ib_umem_num_pages(umem); 192 if (npages == 0 || npages > UINT_MAX) { 193 ret = -EINVAL; 194 goto out; 195 } 196 197 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 198 199 new_pinned = atomic64_add_return(npages, &mm->pinned_vm); 200 if (new_pinned > lock_limit && !capable(CAP_IPC_LOCK)) { 201 atomic64_sub(npages, &mm->pinned_vm); 202 ret = -ENOMEM; 203 goto out; 204 } 205 206 cur_base = addr & PAGE_MASK; 207 208 if (!umem->writable) 209 gup_flags |= FOLL_FORCE; 210 211 while (npages) { 212 cond_resched(); 213 ret = pin_user_pages_fast(cur_base, 214 min_t(unsigned long, npages, 215 PAGE_SIZE / 216 sizeof(struct page *)), 217 gup_flags | FOLL_LONGTERM, page_list); 218 if (ret < 0) 219 goto umem_release; 220 221 cur_base += ret * PAGE_SIZE; 222 npages -= ret; 223 sg = __sg_alloc_table_from_pages( 224 &umem->sg_head, page_list, ret, 0, ret << PAGE_SHIFT, 225 dma_get_max_seg_size(device->dma_device), sg, npages, 226 GFP_KERNEL); 227 umem->sg_nents = umem->sg_head.nents; 228 if (IS_ERR(sg)) { 229 unpin_user_pages_dirty_lock(page_list, ret, 0); 230 ret = PTR_ERR(sg); 231 goto umem_release; 232 } 233 } 234 235 if (access & IB_ACCESS_RELAXED_ORDERING) 236 dma_attr |= DMA_ATTR_WEAK_ORDERING; 237 238 umem->nmap = 239 ib_dma_map_sg_attrs(device, umem->sg_head.sgl, umem->sg_nents, 240 DMA_BIDIRECTIONAL, dma_attr); 241 242 if (!umem->nmap) { 243 ret = -ENOMEM; 244 goto umem_release; 245 } 246 247 ret = 0; 248 goto out; 249 250 umem_release: 251 __ib_umem_release(device, umem, 0); 252 atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm); 253 out: 254 free_page((unsigned long) page_list); 255 umem_kfree: 256 if (ret) { 257 mmdrop(umem->owning_mm); 258 kfree(umem); 259 } 260 return ret ? ERR_PTR(ret) : umem; 261 } 262 EXPORT_SYMBOL(ib_umem_get); 263 264 /** 265 * ib_umem_release - release memory pinned with ib_umem_get 266 * @umem: umem struct to release 267 */ 268 void ib_umem_release(struct ib_umem *umem) 269 { 270 if (!umem) 271 return; 272 if (umem->is_odp) 273 return ib_umem_odp_release(to_ib_umem_odp(umem)); 274 275 __ib_umem_release(umem->ibdev, umem, 1); 276 277 atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm); 278 mmdrop(umem->owning_mm); 279 kfree(umem); 280 } 281 EXPORT_SYMBOL(ib_umem_release); 282 283 /* 284 * Copy from the given ib_umem's pages to the given buffer. 285 * 286 * umem - the umem to copy from 287 * offset - offset to start copying from 288 * dst - destination buffer 289 * length - buffer length 290 * 291 * Returns 0 on success, or an error code. 292 */ 293 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, 294 size_t length) 295 { 296 size_t end = offset + length; 297 int ret; 298 299 if (offset > umem->length || length > umem->length - offset) { 300 pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n", 301 offset, umem->length, end); 302 return -EINVAL; 303 } 304 305 ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->sg_nents, dst, length, 306 offset + ib_umem_offset(umem)); 307 308 if (ret < 0) 309 return ret; 310 else if (ret != length) 311 return -EINVAL; 312 else 313 return 0; 314 } 315 EXPORT_SYMBOL(ib_umem_copy_from); 316