1/*- 2 * SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0 3 * 4 * Copyright (c) 2005 Topspin Communications. All rights reserved. 5 * Copyright (c) 2005 Cisco Systems. All rights reserved. 6 * Copyright (c) 2005 Mellanox Technologies. All rights reserved. 7 * 8 * This software is available to you under a choice of one of two 9 * licenses. You may choose to be licensed under the terms of the GNU 10 * General Public License (GPL) Version 2, available from the file 11 * COPYING in the main directory of this source tree, or the 12 * OpenIB.org BSD license below: 13 * 14 * Redistribution and use in source and binary forms, with or 15 * without modification, are permitted provided that the following 16 * conditions are met: 17 * 18 * - Redistributions of source code must retain the above 19 * copyright notice, this list of conditions and the following 20 * disclaimer. 21 * 22 * - Redistributions in binary form must reproduce the above 23 * copyright notice, this list of conditions and the following 24 * disclaimer in the documentation and/or other materials 25 * provided with the distribution. 26 * 27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 28 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 29 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 30 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 31 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 32 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 33 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 34 * SOFTWARE. 35 */ 36 37#include <sys/cdefs.h> 38#define LINUXKPI_PARAM_PREFIX ibcore_ 39 40#include <linux/mm.h> 41#include <linux/dma-mapping.h> 42#include <linux/sched.h> 43#include <linux/slab.h> 44#include <linux/wait.h> 45#include <rdma/ib_umem_odp.h> 46 47#include "uverbs.h" 48 49#include <sys/priv.h> 50 51static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty) 52{ 53 struct scatterlist *sg; 54 struct page *page; 55 int i; 56 57 if (umem->nmap > 0) 58 ib_dma_unmap_sg(dev, umem->sg_head.sgl, 59 umem->nmap, 60 DMA_BIDIRECTIONAL); 61 62 for_each_sg(umem->sg_head.sgl, sg, umem->npages, i) { 63 64 page = sg_page(sg); 65 put_page(page); 66 } 67 68 sg_free_table(&umem->sg_head); 69 return; 70 71} 72 73/** 74 * ib_umem_get - Pin and DMA map userspace memory. 75 * 76 * If access flags indicate ODP memory, avoid pinning. Instead, stores 77 * the mm for future page fault handling in conjunction with MMU notifiers. 78 * 79 * @context: userspace context to pin memory for 80 * @addr: userspace virtual address to start at 81 * @size: length of region to pin 82 * @access: IB_ACCESS_xxx flags for memory being pinned 83 * @dmasync: flush in-flight DMA when the memory region is written 84 */ 85struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, 86 size_t size, int access, int dmasync) 87{ 88 struct ib_umem *umem; 89 struct page **page_list; 90 struct vm_area_struct **vma_list; 91 unsigned long locked; 92 unsigned long cur_base; 93 unsigned long npages; 94 int ret; 95 int i; 96 struct dma_attrs dma_attrs = { 0 }; 97 struct scatterlist *sg, *sg_list_start; 98 int need_release = 0; 99 unsigned int gup_flags = FOLL_WRITE; 100 101 if (dmasync) 102 dma_attrs.flags |= DMA_ATTR_WRITE_BARRIER; 103 104 if (!size) 105 return ERR_PTR(-EINVAL); 106 107 /* 108 * If the combination of the addr and size requested for this memory 109 * region causes an integer overflow, return error. 110 */ 111 if (((addr + size) < addr) || 112 PAGE_ALIGN(addr + size) < (addr + size)) 113 return ERR_PTR(-EINVAL); 114 115 if (priv_check(curthread, PRIV_VM_MLOCK) != 0) 116 return ERR_PTR(-EPERM); 117 118 umem = kzalloc(sizeof *umem, GFP_KERNEL); 119 if (!umem) 120 return ERR_PTR(-ENOMEM); 121 122 umem->context = context; 123 umem->length = size; 124 umem->address = addr; 125 umem->page_size = PAGE_SIZE; 126 umem->pid = get_pid(task_pid(current)); 127 /* 128 * We ask for writable memory if any of the following 129 * access flags are set. "Local write" and "remote write" 130 * obviously require write access. "Remote atomic" can do 131 * things like fetch and add, which will modify memory, and 132 * "MW bind" can change permissions by binding a window. 133 */ 134 umem->writable = !!(access & 135 (IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE | 136 IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND)); 137 138 if (access & IB_ACCESS_ON_DEMAND) { 139 ret = ib_umem_odp_get(context, umem); 140 if (ret) { 141 kfree(umem); 142 return ERR_PTR(ret); 143 } 144 return umem; 145 } 146 147 umem->odp_data = NULL; 148 149 page_list = (struct page **) __get_free_page(GFP_KERNEL); 150 if (!page_list) { 151 kfree(umem); 152 return ERR_PTR(-ENOMEM); 153 } 154 155 vma_list = (struct vm_area_struct **) __get_free_page(GFP_KERNEL); 156 157 npages = ib_umem_num_pages(umem); 158 159 down_write(¤t->mm->mmap_sem); 160 161 locked = npages + current->mm->pinned_vm; 162 163 cur_base = addr & PAGE_MASK; 164 165 if (npages == 0 || npages > UINT_MAX) { 166 ret = -EINVAL; 167 goto out; 168 } 169 170 ret = sg_alloc_table(&umem->sg_head, npages, GFP_KERNEL); 171 if (ret) 172 goto out; 173 174 if (!umem->writable) 175 gup_flags |= FOLL_FORCE; 176 177 need_release = 1; 178 sg_list_start = umem->sg_head.sgl; 179 180 while (npages) { 181 ret = get_user_pages(cur_base, 182 min_t(unsigned long, npages, 183 PAGE_SIZE / sizeof (struct page *)), 184 gup_flags, page_list, vma_list); 185 186 if (ret < 0) 187 goto out; 188 189 umem->npages += ret; 190 cur_base += ret * PAGE_SIZE; 191 npages -= ret; 192 193 for_each_sg(sg_list_start, sg, ret, i) { 194 sg_set_page(sg, page_list[i], PAGE_SIZE, 0); 195 } 196 197 /* preparing for next loop */ 198 sg_list_start = sg; 199 } 200 201 umem->nmap = ib_dma_map_sg_attrs(context->device, 202 umem->sg_head.sgl, 203 umem->npages, 204 DMA_BIDIRECTIONAL, 205 &dma_attrs); 206 207 if (umem->nmap <= 0) { 208 ret = -ENOMEM; 209 goto out; 210 } 211 212 ret = 0; 213 214out: 215 if (ret < 0) { 216 if (need_release) 217 __ib_umem_release(context->device, umem, 0); 218 put_pid(umem->pid); 219 kfree(umem); 220 } else 221 current->mm->pinned_vm = locked; 222 223 up_write(¤t->mm->mmap_sem); 224 if (vma_list) 225 free_page((unsigned long) vma_list); 226 free_page((unsigned long) page_list); 227 228 return ret < 0 ? ERR_PTR(ret) : umem; 229} 230EXPORT_SYMBOL(ib_umem_get); 231 232static void ib_umem_account(struct work_struct *work) 233{ 234 struct ib_umem *umem = container_of(work, struct ib_umem, work); 235 236 down_write(&umem->mm->mmap_sem); 237 umem->mm->pinned_vm -= umem->diff; 238 up_write(&umem->mm->mmap_sem); 239 mmput(umem->mm); 240 kfree(umem); 241} 242 243/** 244 * ib_umem_release - release memory pinned with ib_umem_get 245 * @umem: umem struct to release 246 */ 247void ib_umem_release(struct ib_umem *umem) 248{ 249 struct mm_struct *mm; 250 struct task_struct *task; 251 unsigned long diff; 252 253 if (!umem) 254 return; 255 256 if (umem->odp_data) { 257 ib_umem_odp_release(umem); 258 return; 259 } 260 261 __ib_umem_release(umem->context->device, umem, 1); 262 263 task = get_pid_task(umem->pid, PIDTYPE_PID); 264 put_pid(umem->pid); 265 if (!task) 266 goto out; 267 mm = get_task_mm(task); 268 put_task_struct(task); 269 if (!mm) 270 goto out; 271 272 diff = ib_umem_num_pages(umem); 273 274 /* 275 * We may be called with the mm's mmap_sem already held. This 276 * can happen when a userspace munmap() is the call that drops 277 * the last reference to our file and calls our release 278 * method. If there are memory regions to destroy, we'll end 279 * up here and not be able to take the mmap_sem. In that case 280 * we defer the vm_locked accounting to the system workqueue. 281 */ 282 if (umem->context->closing) { 283 if (!down_write_trylock(&mm->mmap_sem)) { 284 INIT_WORK(&umem->work, ib_umem_account); 285 umem->mm = mm; 286 umem->diff = diff; 287 288 queue_work(ib_wq, &umem->work); 289 return; 290 } 291 } else 292 down_write(&mm->mmap_sem); 293 294 mm->pinned_vm -= diff; 295 up_write(&mm->mmap_sem); 296 mmput(mm); 297out: 298 kfree(umem); 299} 300EXPORT_SYMBOL(ib_umem_release); 301 302int ib_umem_page_count(struct ib_umem *umem) 303{ 304 int shift; 305 int i; 306 int n; 307 struct scatterlist *sg; 308 309 if (umem->odp_data) 310 return ib_umem_num_pages(umem); 311 312 shift = ilog2(umem->page_size); 313 314 n = 0; 315 for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) 316 n += sg_dma_len(sg) >> shift; 317 318 return n; 319} 320EXPORT_SYMBOL(ib_umem_page_count); 321 322/* 323 * Copy from the given ib_umem's pages to the given buffer. 324 * 325 * umem - the umem to copy from 326 * offset - offset to start copying from 327 * dst - destination buffer 328 * length - buffer length 329 * 330 * Returns 0 on success, or an error code. 331 */ 332int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, 333 size_t length) 334{ 335 size_t end = offset + length; 336 int ret; 337 338 if (offset > umem->length || length > umem->length - offset) { 339 pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n", 340 offset, umem->length, end); 341 return -EINVAL; 342 } 343 344#ifdef __linux__ 345 ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->nmap, dst, length, 346 offset + ib_umem_offset(umem)); 347#else 348 ret = 0; 349#endif 350 if (ret < 0) 351 return ret; 352 else if (ret != length) 353 return -EINVAL; 354 else 355 return 0; 356} 357EXPORT_SYMBOL(ib_umem_copy_from); 358