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19f6d2a6 OG |
1 | /* |
2 | * Copyright 2014 Advanced Micro Devices, Inc. | |
3 | * | |
4 | * Permission is hereby granted, free of charge, to any person obtaining a | |
5 | * copy of this software and associated documentation files (the "Software"), | |
6 | * to deal in the Software without restriction, including without limitation | |
7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
8 | * and/or sell copies of the Software, and to permit persons to whom the | |
9 | * Software is furnished to do so, subject to the following conditions: | |
10 | * | |
11 | * The above copyright notice and this permission notice shall be included in | |
12 | * all copies or substantial portions of the Software. | |
13 | * | |
14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
17 | * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR | |
18 | * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, | |
19 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR | |
20 | * OTHER DEALINGS IN THE SOFTWARE. | |
21 | */ | |
22 | ||
23 | #include <linux/mutex.h> | |
24 | #include <linux/log2.h> | |
25 | #include <linux/sched.h> | |
26 | #include <linux/slab.h> | |
b17f068a | 27 | #include <linux/amd-iommu.h> |
19f6d2a6 | 28 | #include <linux/notifier.h> |
dd59239a AS |
29 | #include <linux/compat.h> |
30 | ||
19f6d2a6 OG |
31 | struct mm_struct; |
32 | ||
33 | #include "kfd_priv.h" | |
34 | ||
35 | /* | |
36 | * Initial size for the array of queues. | |
37 | * The allocated size is doubled each time | |
38 | * it is exceeded up to MAX_PROCESS_QUEUES. | |
39 | */ | |
40 | #define INITIAL_QUEUE_ARRAY_SIZE 16 | |
41 | ||
42 | /* | |
43 | * List of struct kfd_process (field kfd_process). | |
44 | * Unique/indexed by mm_struct* | |
45 | */ | |
46 | #define KFD_PROCESS_TABLE_SIZE 5 /* bits: 32 entries */ | |
47 | static DEFINE_HASHTABLE(kfd_processes_table, KFD_PROCESS_TABLE_SIZE); | |
48 | static DEFINE_MUTEX(kfd_processes_mutex); | |
49 | ||
50 | DEFINE_STATIC_SRCU(kfd_processes_srcu); | |
51 | ||
52 | static struct workqueue_struct *kfd_process_wq; | |
53 | ||
54 | struct kfd_process_release_work { | |
55 | struct work_struct kfd_work; | |
56 | struct kfd_process *p; | |
57 | }; | |
58 | ||
59 | static struct kfd_process *find_process(const struct task_struct *thread); | |
60 | static struct kfd_process *create_process(const struct task_struct *thread); | |
61 | ||
62 | void kfd_process_create_wq(void) | |
63 | { | |
64 | if (!kfd_process_wq) | |
65 | kfd_process_wq = create_workqueue("kfd_process_wq"); | |
66 | } | |
67 | ||
68 | void kfd_process_destroy_wq(void) | |
69 | { | |
70 | if (kfd_process_wq) { | |
71 | flush_workqueue(kfd_process_wq); | |
72 | destroy_workqueue(kfd_process_wq); | |
73 | kfd_process_wq = NULL; | |
74 | } | |
75 | } | |
76 | ||
77 | struct kfd_process *kfd_create_process(const struct task_struct *thread) | |
78 | { | |
79 | struct kfd_process *process; | |
80 | ||
81 | BUG_ON(!kfd_process_wq); | |
82 | ||
83 | if (thread->mm == NULL) | |
84 | return ERR_PTR(-EINVAL); | |
85 | ||
86 | /* Only the pthreads threading model is supported. */ | |
87 | if (thread->group_leader->mm != thread->mm) | |
88 | return ERR_PTR(-EINVAL); | |
89 | ||
90 | /* Take mmap_sem because we call __mmu_notifier_register inside */ | |
91 | down_write(&thread->mm->mmap_sem); | |
92 | ||
93 | /* | |
94 | * take kfd processes mutex before starting of process creation | |
95 | * so there won't be a case where two threads of the same process | |
96 | * create two kfd_process structures | |
97 | */ | |
98 | mutex_lock(&kfd_processes_mutex); | |
99 | ||
100 | /* A prior open of /dev/kfd could have already created the process. */ | |
101 | process = find_process(thread); | |
102 | if (process) | |
103 | pr_debug("kfd: process already found\n"); | |
104 | ||
105 | if (!process) | |
106 | process = create_process(thread); | |
107 | ||
108 | mutex_unlock(&kfd_processes_mutex); | |
109 | ||
110 | up_write(&thread->mm->mmap_sem); | |
111 | ||
112 | return process; | |
113 | } | |
114 | ||
115 | struct kfd_process *kfd_get_process(const struct task_struct *thread) | |
116 | { | |
117 | struct kfd_process *process; | |
118 | ||
119 | if (thread->mm == NULL) | |
120 | return ERR_PTR(-EINVAL); | |
121 | ||
122 | /* Only the pthreads threading model is supported. */ | |
123 | if (thread->group_leader->mm != thread->mm) | |
124 | return ERR_PTR(-EINVAL); | |
125 | ||
126 | process = find_process(thread); | |
127 | ||
128 | return process; | |
129 | } | |
130 | ||
131 | static struct kfd_process *find_process_by_mm(const struct mm_struct *mm) | |
132 | { | |
133 | struct kfd_process *process; | |
134 | ||
135 | hash_for_each_possible_rcu(kfd_processes_table, process, | |
136 | kfd_processes, (uintptr_t)mm) | |
137 | if (process->mm == mm) | |
138 | return process; | |
139 | ||
140 | return NULL; | |
141 | } | |
142 | ||
143 | static struct kfd_process *find_process(const struct task_struct *thread) | |
144 | { | |
145 | struct kfd_process *p; | |
146 | int idx; | |
147 | ||
148 | idx = srcu_read_lock(&kfd_processes_srcu); | |
149 | p = find_process_by_mm(thread->mm); | |
150 | srcu_read_unlock(&kfd_processes_srcu, idx); | |
151 | ||
152 | return p; | |
153 | } | |
154 | ||
155 | static void kfd_process_wq_release(struct work_struct *work) | |
156 | { | |
157 | struct kfd_process_release_work *my_work; | |
158 | struct kfd_process_device *pdd, *temp; | |
159 | struct kfd_process *p; | |
160 | ||
161 | my_work = (struct kfd_process_release_work *) work; | |
162 | ||
163 | p = my_work->p; | |
164 | ||
165 | mutex_lock(&p->mutex); | |
166 | ||
167 | list_for_each_entry_safe(pdd, temp, &p->per_device_data, | |
168 | per_device_list) { | |
b17f068a | 169 | amd_iommu_unbind_pasid(pdd->dev->pdev, p->pasid); |
19f6d2a6 OG |
170 | list_del(&pdd->per_device_list); |
171 | ||
172 | kfree(pdd); | |
173 | } | |
174 | ||
175 | kfd_pasid_free(p->pasid); | |
176 | ||
177 | mutex_unlock(&p->mutex); | |
178 | ||
179 | mutex_destroy(&p->mutex); | |
180 | ||
181 | kfree(p->queues); | |
182 | ||
183 | kfree(p); | |
184 | ||
185 | kfree((void *)work); | |
186 | } | |
187 | ||
188 | static void kfd_process_destroy_delayed(struct rcu_head *rcu) | |
189 | { | |
190 | struct kfd_process_release_work *work; | |
191 | struct kfd_process *p; | |
192 | ||
193 | BUG_ON(!kfd_process_wq); | |
194 | ||
195 | p = container_of(rcu, struct kfd_process, rcu); | |
196 | BUG_ON(atomic_read(&p->mm->mm_count) <= 0); | |
197 | ||
198 | mmdrop(p->mm); | |
199 | ||
200 | work = (struct kfd_process_release_work *) | |
c448a142 | 201 | kmalloc(sizeof(struct kfd_process_release_work), GFP_ATOMIC); |
19f6d2a6 OG |
202 | |
203 | if (work) { | |
204 | INIT_WORK((struct work_struct *) work, kfd_process_wq_release); | |
205 | work->p = p; | |
206 | queue_work(kfd_process_wq, (struct work_struct *) work); | |
207 | } | |
208 | } | |
209 | ||
210 | static void kfd_process_notifier_release(struct mmu_notifier *mn, | |
211 | struct mm_struct *mm) | |
212 | { | |
213 | struct kfd_process *p; | |
214 | ||
215 | /* | |
216 | * The kfd_process structure can not be free because the | |
217 | * mmu_notifier srcu is read locked | |
218 | */ | |
219 | p = container_of(mn, struct kfd_process, mmu_notifier); | |
220 | BUG_ON(p->mm != mm); | |
221 | ||
222 | mutex_lock(&kfd_processes_mutex); | |
223 | hash_del_rcu(&p->kfd_processes); | |
224 | mutex_unlock(&kfd_processes_mutex); | |
225 | synchronize_srcu(&kfd_processes_srcu); | |
226 | ||
45102048 BG |
227 | mutex_lock(&p->mutex); |
228 | ||
229 | /* In case our notifier is called before IOMMU notifier */ | |
230 | pqm_uninit(&p->pqm); | |
231 | ||
232 | mutex_unlock(&p->mutex); | |
233 | ||
19f6d2a6 OG |
234 | /* |
235 | * Because we drop mm_count inside kfd_process_destroy_delayed | |
236 | * and because the mmu_notifier_unregister function also drop | |
237 | * mm_count we need to take an extra count here. | |
238 | */ | |
239 | atomic_inc(&p->mm->mm_count); | |
240 | mmu_notifier_unregister_no_release(&p->mmu_notifier, p->mm); | |
241 | mmu_notifier_call_srcu(&p->rcu, &kfd_process_destroy_delayed); | |
242 | } | |
243 | ||
244 | static const struct mmu_notifier_ops kfd_process_mmu_notifier_ops = { | |
245 | .release = kfd_process_notifier_release, | |
246 | }; | |
247 | ||
248 | static struct kfd_process *create_process(const struct task_struct *thread) | |
249 | { | |
250 | struct kfd_process *process; | |
251 | int err = -ENOMEM; | |
252 | ||
253 | process = kzalloc(sizeof(*process), GFP_KERNEL); | |
254 | ||
255 | if (!process) | |
256 | goto err_alloc_process; | |
257 | ||
258 | process->queues = kmalloc_array(INITIAL_QUEUE_ARRAY_SIZE, | |
259 | sizeof(process->queues[0]), GFP_KERNEL); | |
260 | if (!process->queues) | |
261 | goto err_alloc_queues; | |
262 | ||
263 | process->pasid = kfd_pasid_alloc(); | |
264 | if (process->pasid == 0) | |
265 | goto err_alloc_pasid; | |
266 | ||
267 | mutex_init(&process->mutex); | |
268 | ||
269 | process->mm = thread->mm; | |
270 | ||
271 | /* register notifier */ | |
272 | process->mmu_notifier.ops = &kfd_process_mmu_notifier_ops; | |
273 | err = __mmu_notifier_register(&process->mmu_notifier, process->mm); | |
274 | if (err) | |
275 | goto err_mmu_notifier; | |
276 | ||
277 | hash_add_rcu(kfd_processes_table, &process->kfd_processes, | |
278 | (uintptr_t)process->mm); | |
279 | ||
280 | process->lead_thread = thread->group_leader; | |
281 | ||
282 | process->queue_array_size = INITIAL_QUEUE_ARRAY_SIZE; | |
283 | ||
284 | INIT_LIST_HEAD(&process->per_device_data); | |
285 | ||
45102048 BG |
286 | err = pqm_init(&process->pqm, process); |
287 | if (err != 0) | |
288 | goto err_process_pqm_init; | |
289 | ||
dd59239a AS |
290 | /* init process apertures*/ |
291 | process->is_32bit_user_mode = is_compat_task(); | |
292 | if (kfd_init_apertures(process) != 0) | |
293 | goto err_init_apretures; | |
294 | ||
19f6d2a6 OG |
295 | return process; |
296 | ||
dd59239a AS |
297 | err_init_apretures: |
298 | pqm_uninit(&process->pqm); | |
45102048 BG |
299 | err_process_pqm_init: |
300 | hash_del_rcu(&process->kfd_processes); | |
301 | synchronize_rcu(); | |
302 | mmu_notifier_unregister_no_release(&process->mmu_notifier, process->mm); | |
19f6d2a6 OG |
303 | err_mmu_notifier: |
304 | kfd_pasid_free(process->pasid); | |
305 | err_alloc_pasid: | |
306 | kfree(process->queues); | |
307 | err_alloc_queues: | |
308 | kfree(process); | |
309 | err_alloc_process: | |
310 | return ERR_PTR(err); | |
311 | } | |
312 | ||
313 | struct kfd_process_device *kfd_get_process_device_data(struct kfd_dev *dev, | |
314 | struct kfd_process *p, | |
315 | int create_pdd) | |
316 | { | |
317 | struct kfd_process_device *pdd = NULL; | |
318 | ||
319 | list_for_each_entry(pdd, &p->per_device_data, per_device_list) | |
320 | if (pdd->dev == dev) | |
321 | return pdd; | |
322 | ||
323 | if (create_pdd) { | |
324 | pdd = kzalloc(sizeof(*pdd), GFP_KERNEL); | |
325 | if (pdd != NULL) { | |
326 | pdd->dev = dev; | |
45102048 BG |
327 | INIT_LIST_HEAD(&pdd->qpd.queues_list); |
328 | INIT_LIST_HEAD(&pdd->qpd.priv_queue_list); | |
329 | pdd->qpd.dqm = dev->dqm; | |
19f6d2a6 OG |
330 | list_add(&pdd->per_device_list, &p->per_device_data); |
331 | } | |
332 | } | |
333 | ||
334 | return pdd; | |
335 | } | |
336 | ||
337 | /* | |
338 | * Direct the IOMMU to bind the process (specifically the pasid->mm) | |
339 | * to the device. | |
340 | * Unbinding occurs when the process dies or the device is removed. | |
341 | * | |
342 | * Assumes that the process lock is held. | |
343 | */ | |
344 | struct kfd_process_device *kfd_bind_process_to_device(struct kfd_dev *dev, | |
345 | struct kfd_process *p) | |
346 | { | |
347 | struct kfd_process_device *pdd = kfd_get_process_device_data(dev, p, 1); | |
b17f068a | 348 | int err; |
19f6d2a6 OG |
349 | |
350 | if (pdd == NULL) | |
351 | return ERR_PTR(-ENOMEM); | |
352 | ||
353 | if (pdd->bound) | |
354 | return pdd; | |
355 | ||
b17f068a OG |
356 | err = amd_iommu_bind_pasid(dev->pdev, p->pasid, p->lead_thread); |
357 | if (err < 0) | |
358 | return ERR_PTR(err); | |
359 | ||
19f6d2a6 OG |
360 | pdd->bound = true; |
361 | ||
362 | return pdd; | |
363 | } | |
364 | ||
365 | void kfd_unbind_process_from_device(struct kfd_dev *dev, unsigned int pasid) | |
366 | { | |
367 | struct kfd_process *p; | |
368 | struct kfd_process_device *pdd; | |
369 | int idx, i; | |
370 | ||
371 | BUG_ON(dev == NULL); | |
372 | ||
373 | idx = srcu_read_lock(&kfd_processes_srcu); | |
374 | ||
375 | hash_for_each_rcu(kfd_processes_table, i, p, kfd_processes) | |
376 | if (p->pasid == pasid) | |
377 | break; | |
378 | ||
379 | srcu_read_unlock(&kfd_processes_srcu, idx); | |
380 | ||
381 | BUG_ON(p->pasid != pasid); | |
382 | ||
383 | mutex_lock(&p->mutex); | |
384 | ||
45102048 BG |
385 | pqm_uninit(&p->pqm); |
386 | ||
19f6d2a6 OG |
387 | pdd = kfd_get_process_device_data(dev, p, 0); |
388 | ||
389 | /* | |
390 | * Just mark pdd as unbound, because we still need it to call | |
391 | * amd_iommu_unbind_pasid() in when the process exits. | |
392 | * We don't call amd_iommu_unbind_pasid() here | |
393 | * because the IOMMU called us. | |
394 | */ | |
395 | if (pdd) | |
396 | pdd->bound = false; | |
397 | ||
398 | mutex_unlock(&p->mutex); | |
399 | } | |
400 | ||
401 | struct kfd_process_device *kfd_get_first_process_device_data(struct kfd_process *p) | |
402 | { | |
403 | return list_first_entry(&p->per_device_data, | |
404 | struct kfd_process_device, | |
405 | per_device_list); | |
406 | } | |
407 | ||
408 | struct kfd_process_device *kfd_get_next_process_device_data(struct kfd_process *p, | |
409 | struct kfd_process_device *pdd) | |
410 | { | |
411 | if (list_is_last(&pdd->per_device_list, &p->per_device_data)) | |
412 | return NULL; | |
413 | return list_next_entry(pdd, per_device_list); | |
414 | } | |
415 | ||
416 | bool kfd_has_process_device_data(struct kfd_process *p) | |
417 | { | |
418 | return !(list_empty(&p->per_device_data)); | |
419 | } |