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 static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty) 49 { 50 bool make_dirty = umem->writable && dirty; 51 struct scatterlist *sg; 52 unsigned int i; 53 54 if (dirty) 55 ib_dma_unmap_sgtable_attrs(dev, &umem->sgt_append.sgt, 56 DMA_BIDIRECTIONAL, 0); 57 58 for_each_sgtable_sg(&umem->sgt_append.sgt, sg, i) 59 unpin_user_page_range_dirty_lock(sg_page(sg), 60 DIV_ROUND_UP(sg->length, PAGE_SIZE), make_dirty); 61 62 sg_free_append_table(&umem->sgt_append); 63 } 64 65 /** 66 * ib_umem_find_best_pgsz - Find best HW page size to use for this MR 67 * 68 * @umem: umem struct 69 * @pgsz_bitmap: bitmap of HW supported page sizes 70 * @virt: IOVA 71 * 72 * This helper is intended for HW that support multiple page 73 * sizes but can do only a single page size in an MR. 74 * 75 * Returns 0 if the umem requires page sizes not supported by 76 * the driver to be mapped. Drivers always supporting PAGE_SIZE 77 * or smaller will never see a 0 result. 78 */ 79 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem, 80 unsigned long pgsz_bitmap, 81 unsigned long virt) 82 { 83 struct scatterlist *sg; 84 unsigned long va, pgoff; 85 dma_addr_t mask; 86 int i; 87 88 umem->iova = va = virt; 89 90 if (umem->is_odp) { 91 unsigned int page_size = BIT(to_ib_umem_odp(umem)->page_shift); 92 93 /* ODP must always be self consistent. */ 94 if (!(pgsz_bitmap & page_size)) 95 return 0; 96 return page_size; 97 } 98 99 /* The best result is the smallest page size that results in the minimum 100 * number of required pages. Compute the largest page size that could 101 * work based on VA address bits that don't change. 102 */ 103 mask = pgsz_bitmap & 104 GENMASK(BITS_PER_LONG - 1, 105 bits_per((umem->length - 1 + virt) ^ virt)); 106 /* offset into first SGL */ 107 pgoff = umem->address & ~PAGE_MASK; 108 109 for_each_sgtable_dma_sg(&umem->sgt_append.sgt, sg, i) { 110 /* Walk SGL and reduce max page size if VA/PA bits differ 111 * for any address. 112 */ 113 mask |= (sg_dma_address(sg) + pgoff) ^ va; 114 va += sg_dma_len(sg) - pgoff; 115 /* Except for the last entry, the ending iova alignment sets 116 * the maximum possible page size as the low bits of the iova 117 * must be zero when starting the next chunk. 118 */ 119 if (i != (umem->sgt_append.sgt.nents - 1)) 120 mask |= va; 121 pgoff = 0; 122 } 123 124 /* The mask accumulates 1's in each position where the VA and physical 125 * address differ, thus the length of trailing 0 is the largest page 126 * size that can pass the VA through to the physical. 127 */ 128 if (mask) 129 pgsz_bitmap &= GENMASK(count_trailing_zeros(mask), 0); 130 return pgsz_bitmap ? rounddown_pow_of_two(pgsz_bitmap) : 0; 131 } 132 EXPORT_SYMBOL(ib_umem_find_best_pgsz); 133 134 /** 135 * ib_umem_get - Pin and DMA map userspace memory. 136 * 137 * @device: IB device to connect UMEM 138 * @addr: userspace virtual address to start at 139 * @size: length of region to pin 140 * @access: IB_ACCESS_xxx flags for memory being pinned 141 */ 142 struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, 143 size_t size, int access) 144 { 145 struct ib_umem *umem; 146 struct page **page_list; 147 unsigned long lock_limit; 148 unsigned long new_pinned; 149 unsigned long cur_base; 150 unsigned long dma_attr = 0; 151 struct mm_struct *mm; 152 unsigned long npages; 153 int pinned, ret; 154 unsigned int gup_flags = FOLL_LONGTERM; 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_WRITE; 210 211 while (npages) { 212 cond_resched(); 213 pinned = pin_user_pages_fast(cur_base, 214 min_t(unsigned long, npages, 215 PAGE_SIZE / 216 sizeof(struct page *)), 217 gup_flags, page_list); 218 if (pinned < 0) { 219 ret = pinned; 220 goto umem_release; 221 } 222 223 cur_base += pinned * PAGE_SIZE; 224 npages -= pinned; 225 ret = sg_alloc_append_table_from_pages( 226 &umem->sgt_append, page_list, pinned, 0, 227 pinned << PAGE_SHIFT, ib_dma_max_seg_size(device), 228 npages, GFP_KERNEL); 229 if (ret) { 230 unpin_user_pages_dirty_lock(page_list, pinned, 0); 231 goto umem_release; 232 } 233 } 234 235 if (access & IB_ACCESS_RELAXED_ORDERING) 236 dma_attr |= DMA_ATTR_WEAK_ORDERING; 237 238 ret = ib_dma_map_sgtable_attrs(device, &umem->sgt_append.sgt, 239 DMA_BIDIRECTIONAL, dma_attr); 240 if (ret) 241 goto umem_release; 242 goto out; 243 244 umem_release: 245 __ib_umem_release(device, umem, 0); 246 atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm); 247 out: 248 free_page((unsigned long) page_list); 249 umem_kfree: 250 if (ret) { 251 mmdrop(umem->owning_mm); 252 kfree(umem); 253 } 254 return ret ? ERR_PTR(ret) : umem; 255 } 256 EXPORT_SYMBOL(ib_umem_get); 257 258 /** 259 * ib_umem_release - release memory pinned with ib_umem_get 260 * @umem: umem struct to release 261 */ 262 void ib_umem_release(struct ib_umem *umem) 263 { 264 if (!umem) 265 return; 266 if (umem->is_dmabuf) 267 return ib_umem_dmabuf_release(to_ib_umem_dmabuf(umem)); 268 if (umem->is_odp) 269 return ib_umem_odp_release(to_ib_umem_odp(umem)); 270 271 __ib_umem_release(umem->ibdev, umem, 1); 272 273 atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm); 274 mmdrop(umem->owning_mm); 275 kfree(umem); 276 } 277 EXPORT_SYMBOL(ib_umem_release); 278 279 /* 280 * Copy from the given ib_umem's pages to the given buffer. 281 * 282 * umem - the umem to copy from 283 * offset - offset to start copying from 284 * dst - destination buffer 285 * length - buffer length 286 * 287 * Returns 0 on success, or an error code. 288 */ 289 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, 290 size_t length) 291 { 292 size_t end = offset + length; 293 int ret; 294 295 if (offset > umem->length || length > umem->length - offset) { 296 pr_err("%s not in range. offset: %zd umem length: %zd end: %zd\n", 297 __func__, offset, umem->length, end); 298 return -EINVAL; 299 } 300 301 ret = sg_pcopy_to_buffer(umem->sgt_append.sgt.sgl, 302 umem->sgt_append.sgt.orig_nents, dst, length, 303 offset + ib_umem_offset(umem)); 304 305 if (ret < 0) 306 return ret; 307 else if (ret != length) 308 return -EINVAL; 309 else 310 return 0; 311 } 312 EXPORT_SYMBOL(ib_umem_copy_from); 313