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/*
* Copyright 2014 Advanced Micro Devices, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include <linux/mutex.h>
#include <linux/log2.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/amd-iommu.h>
#include <linux/notifier.h>
#include <linux/compat.h>
struct mm_struct;
#include "kfd_priv.h"
/*
* Initial size for the array of queues.
* The allocated size is doubled each time
* it is exceeded up to MAX_PROCESS_QUEUES.
*/
#define INITIAL_QUEUE_ARRAY_SIZE 16
/*
* List of struct kfd_process (field kfd_process).
* Unique/indexed by mm_struct*
*/
#define KFD_PROCESS_TABLE_SIZE 5 /* bits: 32 entries */
static DEFINE_HASHTABLE(kfd_processes_table, KFD_PROCESS_TABLE_SIZE);
static DEFINE_MUTEX(kfd_processes_mutex);
DEFINE_STATIC_SRCU(kfd_processes_srcu);
static struct workqueue_struct *kfd_process_wq;
struct kfd_process_release_work {
struct work_struct kfd_work;
struct kfd_process *p;
};
static struct kfd_process *find_process(const struct task_struct *thread);
static struct kfd_process *create_process(const struct task_struct *thread);
void kfd_process_create_wq(void)
{
if (!kfd_process_wq)
kfd_process_wq = create_workqueue("kfd_process_wq");
}
void kfd_process_destroy_wq(void)
{
if (kfd_process_wq) {
flush_workqueue(kfd_process_wq);
destroy_workqueue(kfd_process_wq);
kfd_process_wq = NULL;
}
}
struct kfd_process *kfd_create_process(const struct task_struct *thread)
{
struct kfd_process *process;
BUG_ON(!kfd_process_wq);
if (thread->mm == NULL)
return ERR_PTR(-EINVAL);
/* Only the pthreads threading model is supported. */
if (thread->group_leader->mm != thread->mm)
return ERR_PTR(-EINVAL);
/* Take mmap_sem because we call __mmu_notifier_register inside */
down_write(&thread->mm->mmap_sem);
/*
* take kfd processes mutex before starting of process creation
* so there won't be a case where two threads of the same process
* create two kfd_process structures
*/
mutex_lock(&kfd_processes_mutex);
/* A prior open of /dev/kfd could have already created the process. */
process = find_process(thread);
if (process)
pr_debug("kfd: process already found\n");
if (!process)
process = create_process(thread);
mutex_unlock(&kfd_processes_mutex);
up_write(&thread->mm->mmap_sem);
return process;
}
struct kfd_process *kfd_get_process(const struct task_struct *thread)
{
struct kfd_process *process;
if (thread->mm == NULL)
return ERR_PTR(-EINVAL);
/* Only the pthreads threading model is supported. */
if (thread->group_leader->mm != thread->mm)
return ERR_PTR(-EINVAL);
process = find_process(thread);
return process;
}
static struct kfd_process *find_process_by_mm(const struct mm_struct *mm)
{
struct kfd_process *process;
hash_for_each_possible_rcu(kfd_processes_table, process,
kfd_processes, (uintptr_t)mm)
if (process->mm == mm)
return process;
return NULL;
}
static struct kfd_process *find_process(const struct task_struct *thread)
{
struct kfd_process *p;
int idx;
idx = srcu_read_lock(&kfd_processes_srcu);
p = find_process_by_mm(thread->mm);
srcu_read_unlock(&kfd_processes_srcu, idx);
return p;
}
static void kfd_process_wq_release(struct work_struct *work)
{
struct kfd_process_release_work *my_work;
struct kfd_process_device *pdd, *temp;
struct kfd_process *p;
my_work = (struct kfd_process_release_work *) work;
p = my_work->p;
pr_debug("Releasing process (pasid %d) in workqueue\n",
p->pasid);
mutex_lock(&p->mutex);
list_for_each_entry_safe(pdd, temp, &p->per_device_data,
per_device_list) {
pr_debug("Releasing pdd (topology id %d) for process (pasid %d) in workqueue\n",
pdd->dev->id, p->pasid);
amd_iommu_unbind_pasid(pdd->dev->pdev, p->pasid);
list_del(&pdd->per_device_list);
kfree(pdd);
}
kfd_pasid_free(p->pasid);
mutex_unlock(&p->mutex);
mutex_destroy(&p->mutex);
kfree(p->queues);
kfree(p);
kfree((void *)work);
}
static void kfd_process_destroy_delayed(struct rcu_head *rcu)
{
struct kfd_process_release_work *work;
struct kfd_process *p;
BUG_ON(!kfd_process_wq);
p = container_of(rcu, struct kfd_process, rcu);
BUG_ON(atomic_read(&p->mm->mm_count) <= 0);
mmdrop(p->mm);
work = (struct kfd_process_release_work *)
kmalloc(sizeof(struct kfd_process_release_work), GFP_ATOMIC);
if (work) {
INIT_WORK((struct work_struct *) work, kfd_process_wq_release);
work->p = p;
queue_work(kfd_process_wq, (struct work_struct *) work);
}
}
static void kfd_process_notifier_release(struct mmu_notifier *mn,
struct mm_struct *mm)
{
struct kfd_process *p;
/*
* The kfd_process structure can not be free because the
* mmu_notifier srcu is read locked
*/
p = container_of(mn, struct kfd_process, mmu_notifier);
BUG_ON(p->mm != mm);
mutex_lock(&kfd_processes_mutex);
hash_del_rcu(&p->kfd_processes);
mutex_unlock(&kfd_processes_mutex);
synchronize_srcu(&kfd_processes_srcu);
mutex_lock(&p->mutex);
/* In case our notifier is called before IOMMU notifier */
pqm_uninit(&p->pqm);
mutex_unlock(&p->mutex);
/*
* Because we drop mm_count inside kfd_process_destroy_delayed
* and because the mmu_notifier_unregister function also drop
* mm_count we need to take an extra count here.
*/
atomic_inc(&p->mm->mm_count);
mmu_notifier_unregister_no_release(&p->mmu_notifier, p->mm);
mmu_notifier_call_srcu(&p->rcu, &kfd_process_destroy_delayed);
}
static const struct mmu_notifier_ops kfd_process_mmu_notifier_ops = {
.release = kfd_process_notifier_release,
};
static struct kfd_process *create_process(const struct task_struct *thread)
{
struct kfd_process *process;
int err = -ENOMEM;
process = kzalloc(sizeof(*process), GFP_KERNEL);
if (!process)
goto err_alloc_process;
process->queues = kmalloc_array(INITIAL_QUEUE_ARRAY_SIZE,
sizeof(process->queues[0]), GFP_KERNEL);
if (!process->queues)
goto err_alloc_queues;
process->pasid = kfd_pasid_alloc();
if (process->pasid == 0)
goto err_alloc_pasid;
mutex_init(&process->mutex);
process->mm = thread->mm;
/* register notifier */
process->mmu_notifier.ops = &kfd_process_mmu_notifier_ops;
err = __mmu_notifier_register(&process->mmu_notifier, process->mm);
if (err)
goto err_mmu_notifier;
hash_add_rcu(kfd_processes_table, &process->kfd_processes,
(uintptr_t)process->mm);
process->lead_thread = thread->group_leader;
process->queue_array_size = INITIAL_QUEUE_ARRAY_SIZE;
INIT_LIST_HEAD(&process->per_device_data);
err = pqm_init(&process->pqm, process);
if (err != 0)
goto err_process_pqm_init;
/* init process apertures*/
process->is_32bit_user_mode = is_compat_task();
if (kfd_init_apertures(process) != 0)
goto err_init_apretures;
return process;
err_init_apretures:
pqm_uninit(&process->pqm);
err_process_pqm_init:
hash_del_rcu(&process->kfd_processes);
synchronize_rcu();
mmu_notifier_unregister_no_release(&process->mmu_notifier, process->mm);
err_mmu_notifier:
kfd_pasid_free(process->pasid);
err_alloc_pasid:
kfree(process->queues);
err_alloc_queues:
kfree(process);
err_alloc_process:
return ERR_PTR(err);
}
struct kfd_process_device *kfd_get_process_device_data(struct kfd_dev *dev,
struct kfd_process *p)
{
struct kfd_process_device *pdd = NULL;
list_for_each_entry(pdd, &p->per_device_data, per_device_list)
if (pdd->dev == dev)
break;
return pdd;
}
struct kfd_process_device *kfd_create_process_device_data(struct kfd_dev *dev,
struct kfd_process *p)
{
struct kfd_process_device *pdd = NULL;
pdd = kzalloc(sizeof(*pdd), GFP_KERNEL);
if (pdd != NULL) {
pdd->dev = dev;
INIT_LIST_HEAD(&pdd->qpd.queues_list);
INIT_LIST_HEAD(&pdd->qpd.priv_queue_list);
pdd->qpd.dqm = dev->dqm;
list_add(&pdd->per_device_list, &p->per_device_data);
}
return pdd;
}
/*
* Direct the IOMMU to bind the process (specifically the pasid->mm)
* to the device.
* Unbinding occurs when the process dies or the device is removed.
*
* Assumes that the process lock is held.
*/
struct kfd_process_device *kfd_bind_process_to_device(struct kfd_dev *dev,
struct kfd_process *p)
{
struct kfd_process_device *pdd;
int err;
pdd = kfd_get_process_device_data(dev, p);
if (!pdd) {
pr_err("Process device data doesn't exist\n");
return ERR_PTR(-ENOMEM);
}
if (pdd->bound)
return pdd;
err = amd_iommu_bind_pasid(dev->pdev, p->pasid, p->lead_thread);
if (err < 0)
return ERR_PTR(err);
pdd->bound = true;
return pdd;
}
void kfd_unbind_process_from_device(struct kfd_dev *dev, unsigned int pasid)
{
struct kfd_process *p;
struct kfd_process_device *pdd;
int idx, i;
BUG_ON(dev == NULL);
idx = srcu_read_lock(&kfd_processes_srcu);
hash_for_each_rcu(kfd_processes_table, i, p, kfd_processes)
if (p->pasid == pasid)
break;
srcu_read_unlock(&kfd_processes_srcu, idx);
BUG_ON(p->pasid != pasid);
mutex_lock(&p->mutex);
pqm_uninit(&p->pqm);
pdd = kfd_get_process_device_data(dev, p);
/*
* Just mark pdd as unbound, because we still need it to call
* amd_iommu_unbind_pasid() in when the process exits.
* We don't call amd_iommu_unbind_pasid() here
* because the IOMMU called us.
*/
if (pdd)
pdd->bound = false;
mutex_unlock(&p->mutex);
}
struct kfd_process_device *kfd_get_first_process_device_data(struct kfd_process *p)
{
return list_first_entry(&p->per_device_data,
struct kfd_process_device,
per_device_list);
}
struct kfd_process_device *kfd_get_next_process_device_data(struct kfd_process *p,
struct kfd_process_device *pdd)
{
if (list_is_last(&pdd->per_device_list, &p->per_device_data))
return NULL;
return list_next_entry(pdd, per_device_list);
}
bool kfd_has_process_device_data(struct kfd_process *p)
{
return !(list_empty(&p->per_device_data));
}
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