2 * Copyright 2014 Advanced Micro Devices, Inc.
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:
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
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.
23 #include <linux/mutex.h>
24 #include <linux/log2.h>
25 #include <linux/sched.h>
26 #include <linux/slab.h>
27 #include <linux/amd-iommu.h>
28 #include <linux/notifier.h>
29 #include <linux/compat.h>
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.
40 #define INITIAL_QUEUE_ARRAY_SIZE 16
43 * List of struct kfd_process (field kfd_process).
44 * Unique/indexed by mm_struct*
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);
50 DEFINE_STATIC_SRCU(kfd_processes_srcu);
52 static struct workqueue_struct *kfd_process_wq;
54 struct kfd_process_release_work {
55 struct work_struct kfd_work;
56 struct kfd_process *p;
59 static struct kfd_process *find_process(const struct task_struct *thread);
60 static struct kfd_process *create_process(const struct task_struct *thread);
62 void kfd_process_create_wq(void)
65 kfd_process_wq = create_workqueue("kfd_process_wq");
68 void kfd_process_destroy_wq(void)
71 flush_workqueue(kfd_process_wq);
72 destroy_workqueue(kfd_process_wq);
73 kfd_process_wq = NULL;
77 struct kfd_process *kfd_create_process(const struct task_struct *thread)
79 struct kfd_process *process;
81 BUG_ON(!kfd_process_wq);
83 if (thread->mm == NULL)
84 return ERR_PTR(-EINVAL);
86 /* Only the pthreads threading model is supported. */
87 if (thread->group_leader->mm != thread->mm)
88 return ERR_PTR(-EINVAL);
90 /* Take mmap_sem because we call __mmu_notifier_register inside */
91 down_write(&thread->mm->mmap_sem);
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
98 mutex_lock(&kfd_processes_mutex);
100 /* A prior open of /dev/kfd could have already created the process. */
101 process = find_process(thread);
103 pr_debug("kfd: process already found\n");
106 process = create_process(thread);
108 mutex_unlock(&kfd_processes_mutex);
110 up_write(&thread->mm->mmap_sem);
115 struct kfd_process *kfd_get_process(const struct task_struct *thread)
117 struct kfd_process *process;
119 if (thread->mm == NULL)
120 return ERR_PTR(-EINVAL);
122 /* Only the pthreads threading model is supported. */
123 if (thread->group_leader->mm != thread->mm)
124 return ERR_PTR(-EINVAL);
126 process = find_process(thread);
131 static struct kfd_process *find_process_by_mm(const struct mm_struct *mm)
133 struct kfd_process *process;
135 hash_for_each_possible_rcu(kfd_processes_table, process,
136 kfd_processes, (uintptr_t)mm)
137 if (process->mm == mm)
143 static struct kfd_process *find_process(const struct task_struct *thread)
145 struct kfd_process *p;
148 idx = srcu_read_lock(&kfd_processes_srcu);
149 p = find_process_by_mm(thread->mm);
150 srcu_read_unlock(&kfd_processes_srcu, idx);
155 static void kfd_process_wq_release(struct work_struct *work)
157 struct kfd_process_release_work *my_work;
158 struct kfd_process_device *pdd, *temp;
159 struct kfd_process *p;
161 my_work = (struct kfd_process_release_work *) work;
165 pr_debug("Releasing process (pasid %d) in workqueue\n",
168 mutex_lock(&p->mutex);
170 list_for_each_entry_safe(pdd, temp, &p->per_device_data,
172 pr_debug("Releasing pdd (topology id %d) for process (pasid %d) in workqueue\n",
173 pdd->dev->id, p->pasid);
175 amd_iommu_unbind_pasid(pdd->dev->pdev, p->pasid);
176 list_del(&pdd->per_device_list);
181 kfd_pasid_free(p->pasid);
183 mutex_unlock(&p->mutex);
185 mutex_destroy(&p->mutex);
194 static void kfd_process_destroy_delayed(struct rcu_head *rcu)
196 struct kfd_process_release_work *work;
197 struct kfd_process *p;
199 BUG_ON(!kfd_process_wq);
201 p = container_of(rcu, struct kfd_process, rcu);
202 BUG_ON(atomic_read(&p->mm->mm_count) <= 0);
206 work = (struct kfd_process_release_work *)
207 kmalloc(sizeof(struct kfd_process_release_work), GFP_ATOMIC);
210 INIT_WORK((struct work_struct *) work, kfd_process_wq_release);
212 queue_work(kfd_process_wq, (struct work_struct *) work);
216 static void kfd_process_notifier_release(struct mmu_notifier *mn,
217 struct mm_struct *mm)
219 struct kfd_process *p;
222 * The kfd_process structure can not be free because the
223 * mmu_notifier srcu is read locked
225 p = container_of(mn, struct kfd_process, mmu_notifier);
228 mutex_lock(&kfd_processes_mutex);
229 hash_del_rcu(&p->kfd_processes);
230 mutex_unlock(&kfd_processes_mutex);
231 synchronize_srcu(&kfd_processes_srcu);
233 mutex_lock(&p->mutex);
235 /* In case our notifier is called before IOMMU notifier */
238 mutex_unlock(&p->mutex);
241 * Because we drop mm_count inside kfd_process_destroy_delayed
242 * and because the mmu_notifier_unregister function also drop
243 * mm_count we need to take an extra count here.
245 atomic_inc(&p->mm->mm_count);
246 mmu_notifier_unregister_no_release(&p->mmu_notifier, p->mm);
247 mmu_notifier_call_srcu(&p->rcu, &kfd_process_destroy_delayed);
250 static const struct mmu_notifier_ops kfd_process_mmu_notifier_ops = {
251 .release = kfd_process_notifier_release,
254 static struct kfd_process *create_process(const struct task_struct *thread)
256 struct kfd_process *process;
259 process = kzalloc(sizeof(*process), GFP_KERNEL);
262 goto err_alloc_process;
264 process->queues = kmalloc_array(INITIAL_QUEUE_ARRAY_SIZE,
265 sizeof(process->queues[0]), GFP_KERNEL);
266 if (!process->queues)
267 goto err_alloc_queues;
269 process->pasid = kfd_pasid_alloc();
270 if (process->pasid == 0)
271 goto err_alloc_pasid;
273 mutex_init(&process->mutex);
275 process->mm = thread->mm;
277 /* register notifier */
278 process->mmu_notifier.ops = &kfd_process_mmu_notifier_ops;
279 err = __mmu_notifier_register(&process->mmu_notifier, process->mm);
281 goto err_mmu_notifier;
283 hash_add_rcu(kfd_processes_table, &process->kfd_processes,
284 (uintptr_t)process->mm);
286 process->lead_thread = thread->group_leader;
288 process->queue_array_size = INITIAL_QUEUE_ARRAY_SIZE;
290 INIT_LIST_HEAD(&process->per_device_data);
292 err = pqm_init(&process->pqm, process);
294 goto err_process_pqm_init;
296 /* init process apertures*/
297 process->is_32bit_user_mode = is_compat_task();
298 if (kfd_init_apertures(process) != 0)
299 goto err_init_apretures;
304 pqm_uninit(&process->pqm);
305 err_process_pqm_init:
306 hash_del_rcu(&process->kfd_processes);
308 mmu_notifier_unregister_no_release(&process->mmu_notifier, process->mm);
310 kfd_pasid_free(process->pasid);
312 kfree(process->queues);
319 struct kfd_process_device *kfd_get_process_device_data(struct kfd_dev *dev,
320 struct kfd_process *p)
322 struct kfd_process_device *pdd = NULL;
324 list_for_each_entry(pdd, &p->per_device_data, per_device_list)
331 struct kfd_process_device *kfd_create_process_device_data(struct kfd_dev *dev,
332 struct kfd_process *p)
334 struct kfd_process_device *pdd = NULL;
336 pdd = kzalloc(sizeof(*pdd), GFP_KERNEL);
339 INIT_LIST_HEAD(&pdd->qpd.queues_list);
340 INIT_LIST_HEAD(&pdd->qpd.priv_queue_list);
341 pdd->qpd.dqm = dev->dqm;
342 list_add(&pdd->per_device_list, &p->per_device_data);
349 * Direct the IOMMU to bind the process (specifically the pasid->mm)
351 * Unbinding occurs when the process dies or the device is removed.
353 * Assumes that the process lock is held.
355 struct kfd_process_device *kfd_bind_process_to_device(struct kfd_dev *dev,
356 struct kfd_process *p)
358 struct kfd_process_device *pdd;
361 pdd = kfd_get_process_device_data(dev, p);
363 pr_err("Process device data doesn't exist\n");
364 return ERR_PTR(-ENOMEM);
370 err = amd_iommu_bind_pasid(dev->pdev, p->pasid, p->lead_thread);
379 void kfd_unbind_process_from_device(struct kfd_dev *dev, unsigned int pasid)
381 struct kfd_process *p;
382 struct kfd_process_device *pdd;
387 idx = srcu_read_lock(&kfd_processes_srcu);
389 hash_for_each_rcu(kfd_processes_table, i, p, kfd_processes)
390 if (p->pasid == pasid)
393 srcu_read_unlock(&kfd_processes_srcu, idx);
395 BUG_ON(p->pasid != pasid);
397 mutex_lock(&p->mutex);
401 pdd = kfd_get_process_device_data(dev, p);
404 * Just mark pdd as unbound, because we still need it to call
405 * amd_iommu_unbind_pasid() in when the process exits.
406 * We don't call amd_iommu_unbind_pasid() here
407 * because the IOMMU called us.
412 mutex_unlock(&p->mutex);
415 struct kfd_process_device *kfd_get_first_process_device_data(struct kfd_process *p)
417 return list_first_entry(&p->per_device_data,
418 struct kfd_process_device,
422 struct kfd_process_device *kfd_get_next_process_device_data(struct kfd_process *p,
423 struct kfd_process_device *pdd)
425 if (list_is_last(&pdd->per_device_list, &p->per_device_data))
427 return list_next_entry(pdd, per_device_list);
430 bool kfd_has_process_device_data(struct kfd_process *p)
432 return !(list_empty(&p->per_device_data));