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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
48static 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 */
79unsigned 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}
132EXPORT_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 */
142struct 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
244umem_release:
245 __ib_umem_release(device, umem, 0);
246 atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm);
247out:
248 free_page((unsigned long) page_list);
249umem_kfree:
250 if (ret) {
251 mmdrop(umem->owning_mm);
252 kfree(umem);
253 }
254 return ret ? ERR_PTR(ret) : umem;
255}
256EXPORT_SYMBOL(ib_umem_get);
257
258/**
259 * ib_umem_release - release memory pinned with ib_umem_get
260 * @umem: umem struct to release
261 */
262void 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}
277EXPORT_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 */
289int 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}
312EXPORT_SYMBOL(ib_umem_copy_from);
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.h>
38#include <linux/hugetlb.h>
39#include <linux/dma-attrs.h>
40#include <linux/slab.h>
41
42#include "uverbs.h"
43
44#define IB_UMEM_MAX_PAGE_CHUNK \
45 ((PAGE_SIZE - offsetof(struct ib_umem_chunk, page_list)) / \
46 ((void *) &((struct ib_umem_chunk *) 0)->page_list[1] - \
47 (void *) &((struct ib_umem_chunk *) 0)->page_list[0]))
48
49static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)
50{
51 struct ib_umem_chunk *chunk, *tmp;
52 int i;
53
54 list_for_each_entry_safe(chunk, tmp, &umem->chunk_list, list) {
55 ib_dma_unmap_sg(dev, chunk->page_list,
56 chunk->nents, DMA_BIDIRECTIONAL);
57 for (i = 0; i < chunk->nents; ++i) {
58 struct page *page = sg_page(&chunk->page_list[i]);
59
60 if (umem->writable && dirty)
61 set_page_dirty_lock(page);
62 put_page(page);
63 }
64
65 kfree(chunk);
66 }
67}
68
69/**
70 * ib_umem_get - Pin and DMA map userspace memory.
71 * @context: userspace context to pin memory for
72 * @addr: userspace virtual address to start at
73 * @size: length of region to pin
74 * @access: IB_ACCESS_xxx flags for memory being pinned
75 * @dmasync: flush in-flight DMA when the memory region is written
76 */
77struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
78 size_t size, int access, int dmasync)
79{
80 struct ib_umem *umem;
81 struct page **page_list;
82 struct vm_area_struct **vma_list;
83 struct ib_umem_chunk *chunk;
84 unsigned long locked;
85 unsigned long lock_limit;
86 unsigned long cur_base;
87 unsigned long npages;
88 int ret;
89 int off;
90 int i;
91 DEFINE_DMA_ATTRS(attrs);
92
93 if (dmasync)
94 dma_set_attr(DMA_ATTR_WRITE_BARRIER, &attrs);
95
96 if (!can_do_mlock())
97 return ERR_PTR(-EPERM);
98
99 umem = kmalloc(sizeof *umem, GFP_KERNEL);
100 if (!umem)
101 return ERR_PTR(-ENOMEM);
102
103 umem->context = context;
104 umem->length = size;
105 umem->offset = addr & ~PAGE_MASK;
106 umem->page_size = PAGE_SIZE;
107 /*
108 * We ask for writable memory if any access flags other than
109 * "remote read" are set. "Local write" and "remote write"
110 * obviously require write access. "Remote atomic" can do
111 * things like fetch and add, which will modify memory, and
112 * "MW bind" can change permissions by binding a window.
113 */
114 umem->writable = !!(access & ~IB_ACCESS_REMOTE_READ);
115
116 /* We assume the memory is from hugetlb until proved otherwise */
117 umem->hugetlb = 1;
118
119 INIT_LIST_HEAD(&umem->chunk_list);
120
121 page_list = (struct page **) __get_free_page(GFP_KERNEL);
122 if (!page_list) {
123 kfree(umem);
124 return ERR_PTR(-ENOMEM);
125 }
126
127 /*
128 * if we can't alloc the vma_list, it's not so bad;
129 * just assume the memory is not hugetlb memory
130 */
131 vma_list = (struct vm_area_struct **) __get_free_page(GFP_KERNEL);
132 if (!vma_list)
133 umem->hugetlb = 0;
134
135 npages = PAGE_ALIGN(size + umem->offset) >> PAGE_SHIFT;
136
137 down_write(¤t->mm->mmap_sem);
138
139 locked = npages + current->mm->locked_vm;
140 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
141
142 if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
143 ret = -ENOMEM;
144 goto out;
145 }
146
147 cur_base = addr & PAGE_MASK;
148
149 ret = 0;
150 while (npages) {
151 ret = get_user_pages(current, current->mm, cur_base,
152 min_t(unsigned long, npages,
153 PAGE_SIZE / sizeof (struct page *)),
154 1, !umem->writable, page_list, vma_list);
155
156 if (ret < 0)
157 goto out;
158
159 cur_base += ret * PAGE_SIZE;
160 npages -= ret;
161
162 off = 0;
163
164 while (ret) {
165 chunk = kmalloc(sizeof *chunk + sizeof (struct scatterlist) *
166 min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK),
167 GFP_KERNEL);
168 if (!chunk) {
169 ret = -ENOMEM;
170 goto out;
171 }
172
173 chunk->nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK);
174 sg_init_table(chunk->page_list, chunk->nents);
175 for (i = 0; i < chunk->nents; ++i) {
176 if (vma_list &&
177 !is_vm_hugetlb_page(vma_list[i + off]))
178 umem->hugetlb = 0;
179 sg_set_page(&chunk->page_list[i], page_list[i + off], PAGE_SIZE, 0);
180 }
181
182 chunk->nmap = ib_dma_map_sg_attrs(context->device,
183 &chunk->page_list[0],
184 chunk->nents,
185 DMA_BIDIRECTIONAL,
186 &attrs);
187 if (chunk->nmap <= 0) {
188 for (i = 0; i < chunk->nents; ++i)
189 put_page(sg_page(&chunk->page_list[i]));
190 kfree(chunk);
191
192 ret = -ENOMEM;
193 goto out;
194 }
195
196 ret -= chunk->nents;
197 off += chunk->nents;
198 list_add_tail(&chunk->list, &umem->chunk_list);
199 }
200
201 ret = 0;
202 }
203
204out:
205 if (ret < 0) {
206 __ib_umem_release(context->device, umem, 0);
207 kfree(umem);
208 } else
209 current->mm->locked_vm = locked;
210
211 up_write(¤t->mm->mmap_sem);
212 if (vma_list)
213 free_page((unsigned long) vma_list);
214 free_page((unsigned long) page_list);
215
216 return ret < 0 ? ERR_PTR(ret) : umem;
217}
218EXPORT_SYMBOL(ib_umem_get);
219
220static void ib_umem_account(struct work_struct *work)
221{
222 struct ib_umem *umem = container_of(work, struct ib_umem, work);
223
224 down_write(&umem->mm->mmap_sem);
225 umem->mm->locked_vm -= umem->diff;
226 up_write(&umem->mm->mmap_sem);
227 mmput(umem->mm);
228 kfree(umem);
229}
230
231/**
232 * ib_umem_release - release memory pinned with ib_umem_get
233 * @umem: umem struct to release
234 */
235void ib_umem_release(struct ib_umem *umem)
236{
237 struct ib_ucontext *context = umem->context;
238 struct mm_struct *mm;
239 unsigned long diff;
240
241 __ib_umem_release(umem->context->device, umem, 1);
242
243 mm = get_task_mm(current);
244 if (!mm) {
245 kfree(umem);
246 return;
247 }
248
249 diff = PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
250
251 /*
252 * We may be called with the mm's mmap_sem already held. This
253 * can happen when a userspace munmap() is the call that drops
254 * the last reference to our file and calls our release
255 * method. If there are memory regions to destroy, we'll end
256 * up here and not be able to take the mmap_sem. In that case
257 * we defer the vm_locked accounting to the system workqueue.
258 */
259 if (context->closing) {
260 if (!down_write_trylock(&mm->mmap_sem)) {
261 INIT_WORK(&umem->work, ib_umem_account);
262 umem->mm = mm;
263 umem->diff = diff;
264
265 queue_work(ib_wq, &umem->work);
266 return;
267 }
268 } else
269 down_write(&mm->mmap_sem);
270
271 current->mm->locked_vm -= diff;
272 up_write(&mm->mmap_sem);
273 mmput(mm);
274 kfree(umem);
275}
276EXPORT_SYMBOL(ib_umem_release);
277
278int ib_umem_page_count(struct ib_umem *umem)
279{
280 struct ib_umem_chunk *chunk;
281 int shift;
282 int i;
283 int n;
284
285 shift = ilog2(umem->page_size);
286
287 n = 0;
288 list_for_each_entry(chunk, &umem->chunk_list, list)
289 for (i = 0; i < chunk->nmap; ++i)
290 n += sg_dma_len(&chunk->page_list[i]) >> shift;
291
292 return n;
293}
294EXPORT_SYMBOL(ib_umem_page_count);