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
__ib_umem_release(struct ib_device * dev,struct ib_umem * umem,int dirty)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 */
ib_umem_find_best_pgsz(struct ib_umem * umem,unsigned long pgsz_bitmap,unsigned long virt)79 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
80 unsigned long pgsz_bitmap,
81 unsigned long virt)
82 {
83 unsigned long curr_len = 0;
84 dma_addr_t curr_base = ~0;
85 unsigned long va, pgoff;
86 struct scatterlist *sg;
87 dma_addr_t mask;
88 dma_addr_t end;
89 int i;
90
91 umem->iova = va = virt;
92
93 if (umem->is_odp) {
94 unsigned int page_size = BIT(to_ib_umem_odp(umem)->page_shift);
95
96 /* ODP must always be self consistent. */
97 if (!(pgsz_bitmap & page_size))
98 return 0;
99 return page_size;
100 }
101
102 /* The best result is the smallest page size that results in the minimum
103 * number of required pages. Compute the largest page size that could
104 * work based on VA address bits that don't change.
105 */
106 mask = pgsz_bitmap &
107 GENMASK(BITS_PER_LONG - 1,
108 bits_per((umem->length - 1 + virt) ^ virt));
109 /* offset into first SGL */
110 pgoff = umem->address & ~PAGE_MASK;
111
112 for_each_sgtable_dma_sg(&umem->sgt_append.sgt, sg, i) {
113 /* If the current entry is physically contiguous with the previous
114 * one, no need to take its start addresses into consideration.
115 */
116 if (check_add_overflow(curr_base, curr_len, &end) ||
117 end != sg_dma_address(sg)) {
118
119 curr_base = sg_dma_address(sg);
120 curr_len = 0;
121
122 /* Reduce max page size if VA/PA bits differ */
123 mask |= (curr_base + pgoff) ^ va;
124
125 /* The alignment of any VA matching a discontinuity point
126 * in the physical memory sets the maximum possible page
127 * size as this must be a starting point of a new page that
128 * needs to be aligned.
129 */
130 if (i != 0)
131 mask |= va;
132 }
133
134 curr_len += sg_dma_len(sg);
135 va += sg_dma_len(sg) - pgoff;
136
137 pgoff = 0;
138 }
139
140 /* The mask accumulates 1's in each position where the VA and physical
141 * address differ, thus the length of trailing 0 is the largest page
142 * size that can pass the VA through to the physical.
143 */
144 if (mask)
145 pgsz_bitmap &= GENMASK(count_trailing_zeros(mask), 0);
146 return pgsz_bitmap ? rounddown_pow_of_two(pgsz_bitmap) : 0;
147 }
148 EXPORT_SYMBOL(ib_umem_find_best_pgsz);
149
150 /**
151 * ib_umem_get - Pin and DMA map userspace memory.
152 *
153 * @device: IB device to connect UMEM
154 * @addr: userspace virtual address to start at
155 * @size: length of region to pin
156 * @access: IB_ACCESS_xxx flags for memory being pinned
157 */
ib_umem_get(struct ib_device * device,unsigned long addr,size_t size,int access)158 struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
159 size_t size, int access)
160 {
161 struct ib_umem *umem;
162 struct page **page_list;
163 unsigned long lock_limit;
164 unsigned long new_pinned;
165 unsigned long cur_base;
166 unsigned long dma_attr = 0;
167 struct mm_struct *mm;
168 unsigned long npages;
169 int pinned, ret;
170 unsigned int gup_flags = FOLL_LONGTERM;
171
172 /*
173 * If the combination of the addr and size requested for this memory
174 * region causes an integer overflow, return error.
175 */
176 if (((addr + size) < addr) ||
177 PAGE_ALIGN(addr + size) < (addr + size))
178 return ERR_PTR(-EINVAL);
179
180 if (!can_do_mlock())
181 return ERR_PTR(-EPERM);
182
183 if (access & IB_ACCESS_ON_DEMAND)
184 return ERR_PTR(-EOPNOTSUPP);
185
186 umem = kzalloc(sizeof(*umem), GFP_KERNEL);
187 if (!umem)
188 return ERR_PTR(-ENOMEM);
189 umem->ibdev = device;
190 umem->length = size;
191 umem->address = addr;
192 /*
193 * Drivers should call ib_umem_find_best_pgsz() to set the iova
194 * correctly.
195 */
196 umem->iova = addr;
197 umem->writable = ib_access_writable(access);
198 umem->owning_mm = mm = current->mm;
199 mmgrab(mm);
200
201 page_list = (struct page **) __get_free_page(GFP_KERNEL);
202 if (!page_list) {
203 ret = -ENOMEM;
204 goto umem_kfree;
205 }
206
207 npages = ib_umem_num_pages(umem);
208 if (npages == 0 || npages > UINT_MAX) {
209 ret = -EINVAL;
210 goto out;
211 }
212
213 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
214
215 new_pinned = atomic64_add_return(npages, &mm->pinned_vm);
216 if (new_pinned > lock_limit && !capable(CAP_IPC_LOCK)) {
217 atomic64_sub(npages, &mm->pinned_vm);
218 ret = -ENOMEM;
219 goto out;
220 }
221
222 cur_base = addr & PAGE_MASK;
223
224 if (umem->writable)
225 gup_flags |= FOLL_WRITE;
226
227 while (npages) {
228 cond_resched();
229 pinned = pin_user_pages_fast(cur_base,
230 min_t(unsigned long, npages,
231 PAGE_SIZE /
232 sizeof(struct page *)),
233 gup_flags, page_list);
234 if (pinned < 0) {
235 ret = pinned;
236 goto umem_release;
237 }
238
239 cur_base += pinned * PAGE_SIZE;
240 npages -= pinned;
241 ret = sg_alloc_append_table_from_pages(
242 &umem->sgt_append, page_list, pinned, 0,
243 pinned << PAGE_SHIFT, ib_dma_max_seg_size(device),
244 npages, GFP_KERNEL);
245 if (ret) {
246 unpin_user_pages_dirty_lock(page_list, pinned, 0);
247 goto umem_release;
248 }
249 }
250
251 if (access & IB_ACCESS_RELAXED_ORDERING)
252 dma_attr |= DMA_ATTR_WEAK_ORDERING;
253
254 ret = ib_dma_map_sgtable_attrs(device, &umem->sgt_append.sgt,
255 DMA_BIDIRECTIONAL, dma_attr);
256 if (ret)
257 goto umem_release;
258 goto out;
259
260 umem_release:
261 __ib_umem_release(device, umem, 0);
262 atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm);
263 out:
264 free_page((unsigned long) page_list);
265 umem_kfree:
266 if (ret) {
267 mmdrop(umem->owning_mm);
268 kfree(umem);
269 }
270 return ret ? ERR_PTR(ret) : umem;
271 }
272 EXPORT_SYMBOL(ib_umem_get);
273
274 /**
275 * ib_umem_release - release memory pinned with ib_umem_get
276 * @umem: umem struct to release
277 */
ib_umem_release(struct ib_umem * umem)278 void ib_umem_release(struct ib_umem *umem)
279 {
280 if (!umem)
281 return;
282 if (umem->is_dmabuf)
283 return ib_umem_dmabuf_release(to_ib_umem_dmabuf(umem));
284 if (umem->is_odp)
285 return ib_umem_odp_release(to_ib_umem_odp(umem));
286
287 __ib_umem_release(umem->ibdev, umem, 1);
288
289 atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm);
290 mmdrop(umem->owning_mm);
291 kfree(umem);
292 }
293 EXPORT_SYMBOL(ib_umem_release);
294
295 /*
296 * Copy from the given ib_umem's pages to the given buffer.
297 *
298 * umem - the umem to copy from
299 * offset - offset to start copying from
300 * dst - destination buffer
301 * length - buffer length
302 *
303 * Returns 0 on success, or an error code.
304 */
ib_umem_copy_from(void * dst,struct ib_umem * umem,size_t offset,size_t length)305 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
306 size_t length)
307 {
308 size_t end = offset + length;
309 int ret;
310
311 if (offset > umem->length || length > umem->length - offset) {
312 pr_err("%s not in range. offset: %zd umem length: %zd end: %zd\n",
313 __func__, offset, umem->length, end);
314 return -EINVAL;
315 }
316
317 ret = sg_pcopy_to_buffer(umem->sgt_append.sgt.sgl,
318 umem->sgt_append.sgt.orig_nents, dst, length,
319 offset + ib_umem_offset(umem));
320
321 if (ret < 0)
322 return ret;
323 else if (ret != length)
324 return -EINVAL;
325 else
326 return 0;
327 }
328 EXPORT_SYMBOL(ib_umem_copy_from);
329