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 mutex_lock(&p->mutex);
167 list_for_each_entry_safe(pdd, temp, &p->per_device_data,
169 amd_iommu_unbind_pasid(pdd->dev->pdev, p->pasid);
170 list_del(&pdd->per_device_list);
175 kfd_pasid_free(p->pasid);
177 mutex_unlock(&p->mutex);
179 mutex_destroy(&p->mutex);
188 static void kfd_process_destroy_delayed(struct rcu_head *rcu)
190 struct kfd_process_release_work *work;
191 struct kfd_process *p;
193 BUG_ON(!kfd_process_wq);
195 p = container_of(rcu, struct kfd_process, rcu);
196 BUG_ON(atomic_read(&p->mm->mm_count) <= 0);
200 work = (struct kfd_process_release_work *)
201 kmalloc(sizeof(struct kfd_process_release_work), GFP_ATOMIC);
204 INIT_WORK((struct work_struct *) work, kfd_process_wq_release);
206 queue_work(kfd_process_wq, (struct work_struct *) work);
210 static void kfd_process_notifier_release(struct mmu_notifier *mn,
211 struct mm_struct *mm)
213 struct kfd_process *p;
216 * The kfd_process structure can not be free because the
217 * mmu_notifier srcu is read locked
219 p = container_of(mn, struct kfd_process, mmu_notifier);
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);
227 mutex_lock(&p->mutex);
229 /* In case our notifier is called before IOMMU notifier */
232 mutex_unlock(&p->mutex);
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.
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);
244 static const struct mmu_notifier_ops kfd_process_mmu_notifier_ops = {
245 .release = kfd_process_notifier_release,
248 static struct kfd_process *create_process(const struct task_struct *thread)
250 struct kfd_process *process;
253 process = kzalloc(sizeof(*process), GFP_KERNEL);
256 goto err_alloc_process;
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;
263 process->pasid = kfd_pasid_alloc();
264 if (process->pasid == 0)
265 goto err_alloc_pasid;
267 mutex_init(&process->mutex);
269 process->mm = thread->mm;
271 /* register notifier */
272 process->mmu_notifier.ops = &kfd_process_mmu_notifier_ops;
273 err = __mmu_notifier_register(&process->mmu_notifier, process->mm);
275 goto err_mmu_notifier;
277 hash_add_rcu(kfd_processes_table, &process->kfd_processes,
278 (uintptr_t)process->mm);
280 process->lead_thread = thread->group_leader;
282 process->queue_array_size = INITIAL_QUEUE_ARRAY_SIZE;
284 INIT_LIST_HEAD(&process->per_device_data);
286 err = pqm_init(&process->pqm, process);
288 goto err_process_pqm_init;
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;
298 pqm_uninit(&process->pqm);
299 err_process_pqm_init:
300 hash_del_rcu(&process->kfd_processes);
302 mmu_notifier_unregister_no_release(&process->mmu_notifier, process->mm);
304 kfd_pasid_free(process->pasid);
306 kfree(process->queues);
313 struct kfd_process_device *kfd_get_process_device_data(struct kfd_dev *dev,
314 struct kfd_process *p,
317 struct kfd_process_device *pdd = NULL;
319 list_for_each_entry(pdd, &p->per_device_data, per_device_list)
324 pdd = kzalloc(sizeof(*pdd), GFP_KERNEL);
327 INIT_LIST_HEAD(&pdd->qpd.queues_list);
328 INIT_LIST_HEAD(&pdd->qpd.priv_queue_list);
329 pdd->qpd.dqm = dev->dqm;
330 list_add(&pdd->per_device_list, &p->per_device_data);
338 * Direct the IOMMU to bind the process (specifically the pasid->mm)
340 * Unbinding occurs when the process dies or the device is removed.
342 * Assumes that the process lock is held.
344 struct kfd_process_device *kfd_bind_process_to_device(struct kfd_dev *dev,
345 struct kfd_process *p)
347 struct kfd_process_device *pdd = kfd_get_process_device_data(dev, p, 1);
351 return ERR_PTR(-ENOMEM);
356 err = amd_iommu_bind_pasid(dev->pdev, p->pasid, p->lead_thread);
365 void kfd_unbind_process_from_device(struct kfd_dev *dev, unsigned int pasid)
367 struct kfd_process *p;
368 struct kfd_process_device *pdd;
373 idx = srcu_read_lock(&kfd_processes_srcu);
375 hash_for_each_rcu(kfd_processes_table, i, p, kfd_processes)
376 if (p->pasid == pasid)
379 srcu_read_unlock(&kfd_processes_srcu, idx);
381 BUG_ON(p->pasid != pasid);
383 mutex_lock(&p->mutex);
387 pdd = kfd_get_process_device_data(dev, p, 0);
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.
398 mutex_unlock(&p->mutex);
401 struct kfd_process_device *kfd_get_first_process_device_data(struct kfd_process *p)
403 return list_first_entry(&p->per_device_data,
404 struct kfd_process_device,
408 struct kfd_process_device *kfd_get_next_process_device_data(struct kfd_process *p,
409 struct kfd_process_device *pdd)
411 if (list_is_last(&pdd->per_device_list, &p->per_device_data))
413 return list_next_entry(pdd, per_device_list);
416 bool kfd_has_process_device_data(struct kfd_process *p)
418 return !(list_empty(&p->per_device_data));