1 /*
2 * Copyright 2014 Advanced Micro Devices, Inc.
3 * All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sub license, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
16 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
17 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
18 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
19 * USE OR OTHER DEALINGS IN THE SOFTWARE.
20 *
21 * The above copyright notice and this permission notice (including the
22 * next paragraph) shall be included in all copies or substantial portions
23 * of the Software.
24 *
25 */
26 /*
27 * Authors:
28 * Christian König <christian.koenig@amd.com>
29 */
30
31 /**
32 * DOC: MMU Notifier
33 *
34 * For coherent userptr handling registers an MMU notifier to inform the driver
35 * about updates on the page tables of a process.
36 *
37 * When somebody tries to invalidate the page tables we block the update until
38 * all operations on the pages in question are completed, then those pages are
39 * marked as accessed and also dirty if it wasn't a read only access.
40 *
41 * New command submissions using the userptrs in question are delayed until all
42 * page table invalidation are completed and we once more see a coherent process
43 * address space.
44 */
45
46 #include <linux/firmware.h>
47 #include <linux/module.h>
48 #include <drm/drm.h>
49
50 #include "amdgpu.h"
51 #include "amdgpu_amdkfd.h"
52
53 /**
54 * amdgpu_mn_invalidate_gfx - callback to notify about mm change
55 *
56 * @mni: the range (mm) is about to update
57 * @range: details on the invalidation
58 * @cur_seq: Value to pass to mmu_interval_set_seq()
59 *
60 * Block for operations on BOs to finish and mark pages as accessed and
61 * potentially dirty.
62 */
amdgpu_mn_invalidate_gfx(struct mmu_interval_notifier * mni,const struct mmu_notifier_range * range,unsigned long cur_seq)63 static bool amdgpu_mn_invalidate_gfx(struct mmu_interval_notifier *mni,
64 const struct mmu_notifier_range *range,
65 unsigned long cur_seq)
66 {
67 struct amdgpu_bo *bo = container_of(mni, struct amdgpu_bo, notifier);
68 struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
69 long r;
70
71 if (!mmu_notifier_range_blockable(range))
72 return false;
73
74 mutex_lock(&adev->notifier_lock);
75
76 mmu_interval_set_seq(mni, cur_seq);
77
78 r = dma_resv_wait_timeout(bo->tbo.base.resv, DMA_RESV_USAGE_BOOKKEEP,
79 false, MAX_SCHEDULE_TIMEOUT);
80 mutex_unlock(&adev->notifier_lock);
81 if (r <= 0)
82 DRM_ERROR("(%ld) failed to wait for user bo\n", r);
83 return true;
84 }
85
86 static const struct mmu_interval_notifier_ops amdgpu_mn_gfx_ops = {
87 .invalidate = amdgpu_mn_invalidate_gfx,
88 };
89
90 /**
91 * amdgpu_mn_invalidate_hsa - callback to notify about mm change
92 *
93 * @mni: the range (mm) is about to update
94 * @range: details on the invalidation
95 * @cur_seq: Value to pass to mmu_interval_set_seq()
96 *
97 * We temporarily evict the BO attached to this range. This necessitates
98 * evicting all user-mode queues of the process.
99 */
amdgpu_mn_invalidate_hsa(struct mmu_interval_notifier * mni,const struct mmu_notifier_range * range,unsigned long cur_seq)100 static bool amdgpu_mn_invalidate_hsa(struct mmu_interval_notifier *mni,
101 const struct mmu_notifier_range *range,
102 unsigned long cur_seq)
103 {
104 struct amdgpu_bo *bo = container_of(mni, struct amdgpu_bo, notifier);
105 struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
106
107 if (!mmu_notifier_range_blockable(range))
108 return false;
109
110 mutex_lock(&adev->notifier_lock);
111
112 mmu_interval_set_seq(mni, cur_seq);
113
114 amdgpu_amdkfd_evict_userptr(bo->kfd_bo, bo->notifier.mm);
115 mutex_unlock(&adev->notifier_lock);
116
117 return true;
118 }
119
120 static const struct mmu_interval_notifier_ops amdgpu_mn_hsa_ops = {
121 .invalidate = amdgpu_mn_invalidate_hsa,
122 };
123
124 /**
125 * amdgpu_mn_register - register a BO for notifier updates
126 *
127 * @bo: amdgpu buffer object
128 * @addr: userptr addr we should monitor
129 *
130 * Registers a mmu_notifier for the given BO at the specified address.
131 * Returns 0 on success, -ERRNO if anything goes wrong.
132 */
amdgpu_mn_register(struct amdgpu_bo * bo,unsigned long addr)133 int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
134 {
135 if (bo->kfd_bo)
136 return mmu_interval_notifier_insert(&bo->notifier, current->mm,
137 addr, amdgpu_bo_size(bo),
138 &amdgpu_mn_hsa_ops);
139 return mmu_interval_notifier_insert(&bo->notifier, current->mm, addr,
140 amdgpu_bo_size(bo),
141 &amdgpu_mn_gfx_ops);
142 }
143
144 /**
145 * amdgpu_mn_unregister - unregister a BO for notifier updates
146 *
147 * @bo: amdgpu buffer object
148 *
149 * Remove any registration of mmu notifier updates from the buffer object.
150 */
amdgpu_mn_unregister(struct amdgpu_bo * bo)151 void amdgpu_mn_unregister(struct amdgpu_bo *bo)
152 {
153 if (!bo->notifier.mm)
154 return;
155 mmu_interval_notifier_remove(&bo->notifier);
156 bo->notifier.mm = NULL;
157 }
158
amdgpu_hmm_range_get_pages(struct mmu_interval_notifier * notifier,struct mm_struct * mm,struct page ** pages,uint64_t start,uint64_t npages,struct hmm_range ** phmm_range,bool readonly,bool mmap_locked,void * owner)159 int amdgpu_hmm_range_get_pages(struct mmu_interval_notifier *notifier,
160 struct mm_struct *mm, struct page **pages,
161 uint64_t start, uint64_t npages,
162 struct hmm_range **phmm_range, bool readonly,
163 bool mmap_locked, void *owner)
164 {
165 struct hmm_range *hmm_range;
166 unsigned long timeout;
167 unsigned long i;
168 unsigned long *pfns;
169 int r = 0;
170
171 hmm_range = kzalloc(sizeof(*hmm_range), GFP_KERNEL);
172 if (unlikely(!hmm_range))
173 return -ENOMEM;
174
175 pfns = kvmalloc_array(npages, sizeof(*pfns), GFP_KERNEL);
176 if (unlikely(!pfns)) {
177 r = -ENOMEM;
178 goto out_free_range;
179 }
180
181 hmm_range->notifier = notifier;
182 hmm_range->default_flags = HMM_PFN_REQ_FAULT;
183 if (!readonly)
184 hmm_range->default_flags |= HMM_PFN_REQ_WRITE;
185 hmm_range->hmm_pfns = pfns;
186 hmm_range->start = start;
187 hmm_range->end = start + npages * PAGE_SIZE;
188 hmm_range->dev_private_owner = owner;
189
190 /* Assuming 512MB takes maxmium 1 second to fault page address */
191 timeout = max(npages >> 17, 1ULL) * HMM_RANGE_DEFAULT_TIMEOUT;
192 timeout = jiffies + msecs_to_jiffies(timeout);
193
194 retry:
195 hmm_range->notifier_seq = mmu_interval_read_begin(notifier);
196
197 if (likely(!mmap_locked))
198 mmap_read_lock(mm);
199
200 r = hmm_range_fault(hmm_range);
201
202 if (likely(!mmap_locked))
203 mmap_read_unlock(mm);
204 if (unlikely(r)) {
205 /*
206 * FIXME: This timeout should encompass the retry from
207 * mmu_interval_read_retry() as well.
208 */
209 if (r == -EBUSY && !time_after(jiffies, timeout))
210 goto retry;
211 goto out_free_pfns;
212 }
213
214 /*
215 * Due to default_flags, all pages are HMM_PFN_VALID or
216 * hmm_range_fault() fails. FIXME: The pages cannot be touched outside
217 * the notifier_lock, and mmu_interval_read_retry() must be done first.
218 */
219 for (i = 0; pages && i < npages; i++)
220 pages[i] = hmm_pfn_to_page(pfns[i]);
221
222 *phmm_range = hmm_range;
223
224 return 0;
225
226 out_free_pfns:
227 kvfree(pfns);
228 out_free_range:
229 kfree(hmm_range);
230
231 return r;
232 }
233
amdgpu_hmm_range_get_pages_done(struct hmm_range * hmm_range)234 int amdgpu_hmm_range_get_pages_done(struct hmm_range *hmm_range)
235 {
236 int r;
237
238 r = mmu_interval_read_retry(hmm_range->notifier,
239 hmm_range->notifier_seq);
240 kvfree(hmm_range->hmm_pfns);
241 kfree(hmm_range);
242
243 return r;
244 }
245