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 * Copyright (c) 2020 Intel Corporation. All rights reserved. 6 * 7 * This software is available to you under a choice of one of two 8 * licenses. You may choose to be licensed under the terms of the GNU 9 * General Public License (GPL) Version 2, available from the file 10 * COPYING in the main directory of this source tree, or the 11 * OpenIB.org BSD license below: 12 * 13 * Redistribution and use in source and binary forms, with or 14 * without modification, are permitted provided that the following 15 * conditions are met: 16 * 17 * - Redistributions of source code must retain the above 18 * copyright notice, this list of conditions and the following 19 * disclaimer. 20 * 21 * - Redistributions in binary form must reproduce the above 22 * copyright notice, this list of conditions and the following 23 * disclaimer in the documentation and/or other materials 24 * provided with the distribution. 25 * 26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 27 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 28 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 29 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 30 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 31 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 32 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 33 * SOFTWARE. 34 */ 35 36 #include <linux/mm.h> 37 #include <linux/dma-mapping.h> 38 #include <linux/sched/signal.h> 39 #include <linux/sched/mm.h> 40 #include <linux/export.h> 41 #include <linux/slab.h> 42 #include <linux/pagemap.h> 43 #include <linux/count_zeros.h> 44 #include <rdma/ib_umem_odp.h> 45 46 #include "uverbs.h" 47 48 #define RESCHED_LOOP_CNT_THRESHOLD 0x1000 49 50 static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty) 51 { 52 bool make_dirty = umem->writable && dirty; 53 struct scatterlist *sg; 54 unsigned int i; 55 56 if (dirty) 57 ib_dma_unmap_sgtable_attrs(dev, &umem->sgt_append.sgt, 58 DMA_BIDIRECTIONAL, 0); 59 60 for_each_sgtable_sg(&umem->sgt_append.sgt, sg, i) { 61 unpin_user_page_range_dirty_lock(sg_page(sg), 62 DIV_ROUND_UP(sg->length, PAGE_SIZE), make_dirty); 63 64 if (i && !(i % RESCHED_LOOP_CNT_THRESHOLD)) 65 cond_resched(); 66 } 67 68 sg_free_append_table(&umem->sgt_append); 69 } 70 71 /** 72 * ib_umem_find_best_pgsz - Find best HW page size to use for this MR 73 * 74 * @umem: umem struct 75 * @pgsz_bitmap: bitmap of HW supported page sizes 76 * @virt: IOVA 77 * 78 * This helper is intended for HW that support multiple page 79 * sizes but can do only a single page size in an MR. 80 * 81 * Returns 0 if the umem requires page sizes not supported by 82 * the driver to be mapped. Drivers always supporting PAGE_SIZE 83 * or smaller will never see a 0 result. 84 */ 85 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem, 86 unsigned long pgsz_bitmap, 87 unsigned long virt) 88 { 89 unsigned long curr_len = 0; 90 dma_addr_t curr_base = ~0; 91 unsigned long va, pgoff; 92 struct scatterlist *sg; 93 dma_addr_t mask; 94 dma_addr_t end; 95 int i; 96 97 umem->iova = va = virt; 98 99 if (umem->is_odp) { 100 unsigned int page_size = BIT(to_ib_umem_odp(umem)->page_shift); 101 102 /* ODP must always be self consistent. */ 103 if (!(pgsz_bitmap & page_size)) 104 return 0; 105 return page_size; 106 } 107 108 /* The best result is the smallest page size that results in the minimum 109 * number of required pages. Compute the largest page size that could 110 * work based on VA address bits that don't change. 111 */ 112 mask = pgsz_bitmap & 113 GENMASK(BITS_PER_LONG - 1, 114 bits_per((umem->length - 1 + virt) ^ virt)); 115 /* offset into first SGL */ 116 pgoff = umem->address & ~PAGE_MASK; 117 118 for_each_sgtable_dma_sg(&umem->sgt_append.sgt, sg, i) { 119 /* If the current entry is physically contiguous with the previous 120 * one, no need to take its start addresses into consideration. 121 */ 122 if (check_add_overflow(curr_base, curr_len, &end) || 123 end != sg_dma_address(sg)) { 124 125 curr_base = sg_dma_address(sg); 126 curr_len = 0; 127 128 /* Reduce max page size if VA/PA bits differ */ 129 mask |= (curr_base + pgoff) ^ va; 130 131 /* The alignment of any VA matching a discontinuity point 132 * in the physical memory sets the maximum possible page 133 * size as this must be a starting point of a new page that 134 * needs to be aligned. 135 */ 136 if (i != 0) 137 mask |= va; 138 } 139 140 curr_len += sg_dma_len(sg); 141 va += sg_dma_len(sg) - pgoff; 142 143 pgoff = 0; 144 } 145 146 /* The mask accumulates 1's in each position where the VA and physical 147 * address differ, thus the length of trailing 0 is the largest page 148 * size that can pass the VA through to the physical. 149 */ 150 if (mask) 151 pgsz_bitmap &= GENMASK(count_trailing_zeros(mask), 0); 152 return pgsz_bitmap ? rounddown_pow_of_two(pgsz_bitmap) : 0; 153 } 154 EXPORT_SYMBOL(ib_umem_find_best_pgsz); 155 156 /** 157 * ib_umem_get - Pin and DMA map userspace memory. 158 * 159 * @device: IB device to connect UMEM 160 * @addr: userspace virtual address to start at 161 * @size: length of region to pin 162 * @access: IB_ACCESS_xxx flags for memory being pinned 163 */ 164 struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, 165 size_t size, int access) 166 { 167 struct ib_umem *umem; 168 struct page **page_list; 169 unsigned long lock_limit; 170 unsigned long new_pinned; 171 unsigned long cur_base; 172 unsigned long dma_attr = 0; 173 struct mm_struct *mm; 174 unsigned long npages; 175 int pinned, ret; 176 unsigned int gup_flags = FOLL_LONGTERM; 177 178 /* 179 * If the combination of the addr and size requested for this memory 180 * region causes an integer overflow, return error. 181 */ 182 if (((addr + size) < addr) || 183 PAGE_ALIGN(addr + size) < (addr + size)) 184 return ERR_PTR(-EINVAL); 185 186 if (!can_do_mlock()) 187 return ERR_PTR(-EPERM); 188 189 if (access & IB_ACCESS_ON_DEMAND) 190 return ERR_PTR(-EOPNOTSUPP); 191 192 umem = kzalloc(sizeof(*umem), GFP_KERNEL); 193 if (!umem) 194 return ERR_PTR(-ENOMEM); 195 umem->ibdev = device; 196 umem->length = size; 197 umem->address = addr; 198 /* 199 * Drivers should call ib_umem_find_best_pgsz() to set the iova 200 * correctly. 201 */ 202 umem->iova = addr; 203 umem->writable = ib_access_writable(access); 204 umem->owning_mm = mm = current->mm; 205 mmgrab(mm); 206 207 page_list = (struct page **) __get_free_page(GFP_KERNEL); 208 if (!page_list) { 209 ret = -ENOMEM; 210 goto umem_kfree; 211 } 212 213 npages = ib_umem_num_pages(umem); 214 if (npages == 0 || npages > UINT_MAX) { 215 ret = -EINVAL; 216 goto out; 217 } 218 219 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 220 221 new_pinned = atomic64_add_return(npages, &mm->pinned_vm); 222 if (new_pinned > lock_limit && !capable(CAP_IPC_LOCK)) { 223 atomic64_sub(npages, &mm->pinned_vm); 224 ret = -ENOMEM; 225 goto out; 226 } 227 228 cur_base = addr & PAGE_MASK; 229 230 if (umem->writable) 231 gup_flags |= FOLL_WRITE; 232 233 while (npages) { 234 cond_resched(); 235 pinned = pin_user_pages_fast(cur_base, 236 min_t(unsigned long, npages, 237 PAGE_SIZE / 238 sizeof(struct page *)), 239 gup_flags, page_list); 240 if (pinned < 0) { 241 ret = pinned; 242 goto umem_release; 243 } 244 245 cur_base += pinned * PAGE_SIZE; 246 npages -= pinned; 247 ret = sg_alloc_append_table_from_pages( 248 &umem->sgt_append, page_list, pinned, 0, 249 pinned << PAGE_SHIFT, ib_dma_max_seg_size(device), 250 npages, GFP_KERNEL); 251 if (ret) { 252 unpin_user_pages_dirty_lock(page_list, pinned, 0); 253 goto umem_release; 254 } 255 } 256 257 if (access & IB_ACCESS_RELAXED_ORDERING) 258 dma_attr |= DMA_ATTR_WEAK_ORDERING; 259 260 ret = ib_dma_map_sgtable_attrs(device, &umem->sgt_append.sgt, 261 DMA_BIDIRECTIONAL, dma_attr); 262 if (ret) 263 goto umem_release; 264 goto out; 265 266 umem_release: 267 __ib_umem_release(device, umem, 0); 268 atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm); 269 out: 270 free_page((unsigned long) page_list); 271 umem_kfree: 272 if (ret) { 273 mmdrop(umem->owning_mm); 274 kfree(umem); 275 } 276 return ret ? ERR_PTR(ret) : umem; 277 } 278 EXPORT_SYMBOL(ib_umem_get); 279 280 /** 281 * ib_umem_release - release memory pinned with ib_umem_get 282 * @umem: umem struct to release 283 */ 284 void ib_umem_release(struct ib_umem *umem) 285 { 286 if (!umem) 287 return; 288 if (umem->is_dmabuf) 289 return ib_umem_dmabuf_release(to_ib_umem_dmabuf(umem)); 290 if (umem->is_odp) 291 return ib_umem_odp_release(to_ib_umem_odp(umem)); 292 293 __ib_umem_release(umem->ibdev, umem, 1); 294 295 atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm); 296 mmdrop(umem->owning_mm); 297 kfree(umem); 298 } 299 EXPORT_SYMBOL(ib_umem_release); 300 301 /* 302 * Copy from the given ib_umem's pages to the given buffer. 303 * 304 * umem - the umem to copy from 305 * offset - offset to start copying from 306 * dst - destination buffer 307 * length - buffer length 308 * 309 * Returns 0 on success, or an error code. 310 */ 311 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, 312 size_t length) 313 { 314 size_t end = offset + length; 315 int ret; 316 317 if (offset > umem->length || length > umem->length - offset) { 318 pr_err("%s not in range. offset: %zd umem length: %zd end: %zd\n", 319 __func__, offset, umem->length, end); 320 return -EINVAL; 321 } 322 323 ret = sg_pcopy_to_buffer(umem->sgt_append.sgt.sgl, 324 umem->sgt_append.sgt.orig_nents, dst, length, 325 offset + ib_umem_offset(umem)); 326 327 if (ret < 0) 328 return ret; 329 else if (ret != length) 330 return -EINVAL; 331 else 332 return 0; 333 } 334 EXPORT_SYMBOL(ib_umem_copy_from); 335