uacce: Remove mm_exit() op
The mm_exit() op will be removed from the SVA API. When a process dies and its mm goes away, the IOMMU driver won't notify device drivers anymore. Drivers should expect to handle a lot more aborted DMA. On the upside, it does greatly simplify the queue management. The uacce_mm struct, that tracks all queues bound to an mm, was only used by the mm_exit() callback. Remove it. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Acked-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Acked-by: Lu Baolu <baolu.lu@linux.intel.com> Acked-by: Zhangfei Gao <zhangfei.gao@linaro.org> Link: https://lore.kernel.org/r/20200423125329.782066-2-jean-philippe@linaro.org Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Jean-Philippe Brucker
Joerg Roedel
Родитель
da656a0425
Коммит
fb01562e5a
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@ -90,109 +90,39 @@ static long uacce_fops_compat_ioctl(struct file *filep,
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}
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#endif
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static int uacce_sva_exit(struct device *dev, struct iommu_sva *handle,
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void *data)
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static int uacce_bind_queue(struct uacce_device *uacce, struct uacce_queue *q)
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{
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struct uacce_mm *uacce_mm = data;
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struct uacce_queue *q;
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int pasid;
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struct iommu_sva *handle;
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/*
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* No new queue can be added concurrently because no caller can have a
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* reference to this mm. But there may be concurrent calls to
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* uacce_mm_put(), so we need the lock.
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*/
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mutex_lock(&uacce_mm->lock);
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list_for_each_entry(q, &uacce_mm->queues, list)
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uacce_put_queue(q);
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uacce_mm->mm = NULL;
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mutex_unlock(&uacce_mm->lock);
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if (!(uacce->flags & UACCE_DEV_SVA))
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return 0;
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handle = iommu_sva_bind_device(uacce->parent, current->mm, NULL);
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if (IS_ERR(handle))
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return PTR_ERR(handle);
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pasid = iommu_sva_get_pasid(handle);
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if (pasid == IOMMU_PASID_INVALID) {
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iommu_sva_unbind_device(handle);
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return -ENODEV;
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}
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q->handle = handle;
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q->pasid = pasid;
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return 0;
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}
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static struct iommu_sva_ops uacce_sva_ops = {
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.mm_exit = uacce_sva_exit,
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};
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static struct uacce_mm *uacce_mm_get(struct uacce_device *uacce,
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struct uacce_queue *q,
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struct mm_struct *mm)
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static void uacce_unbind_queue(struct uacce_queue *q)
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{
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struct uacce_mm *uacce_mm = NULL;
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struct iommu_sva *handle = NULL;
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int ret;
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lockdep_assert_held(&uacce->mm_lock);
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list_for_each_entry(uacce_mm, &uacce->mm_list, list) {
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if (uacce_mm->mm == mm) {
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mutex_lock(&uacce_mm->lock);
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list_add(&q->list, &uacce_mm->queues);
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mutex_unlock(&uacce_mm->lock);
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return uacce_mm;
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}
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}
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uacce_mm = kzalloc(sizeof(*uacce_mm), GFP_KERNEL);
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if (!uacce_mm)
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return NULL;
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if (uacce->flags & UACCE_DEV_SVA) {
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/*
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* Safe to pass an incomplete uacce_mm, since mm_exit cannot
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* fire while we hold a reference to the mm.
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*/
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handle = iommu_sva_bind_device(uacce->parent, mm, uacce_mm);
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if (IS_ERR(handle))
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goto err_free;
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ret = iommu_sva_set_ops(handle, &uacce_sva_ops);
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if (ret)
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goto err_unbind;
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uacce_mm->pasid = iommu_sva_get_pasid(handle);
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if (uacce_mm->pasid == IOMMU_PASID_INVALID)
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goto err_unbind;
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}
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uacce_mm->mm = mm;
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uacce_mm->handle = handle;
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INIT_LIST_HEAD(&uacce_mm->queues);
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mutex_init(&uacce_mm->lock);
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list_add(&q->list, &uacce_mm->queues);
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list_add(&uacce_mm->list, &uacce->mm_list);
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return uacce_mm;
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err_unbind:
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if (handle)
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iommu_sva_unbind_device(handle);
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err_free:
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kfree(uacce_mm);
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return NULL;
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}
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static void uacce_mm_put(struct uacce_queue *q)
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{
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struct uacce_mm *uacce_mm = q->uacce_mm;
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lockdep_assert_held(&q->uacce->mm_lock);
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mutex_lock(&uacce_mm->lock);
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list_del(&q->list);
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mutex_unlock(&uacce_mm->lock);
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if (list_empty(&uacce_mm->queues)) {
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if (uacce_mm->handle)
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iommu_sva_unbind_device(uacce_mm->handle);
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list_del(&uacce_mm->list);
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kfree(uacce_mm);
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}
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if (!q->handle)
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return;
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iommu_sva_unbind_device(q->handle);
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q->handle = NULL;
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}
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static int uacce_fops_open(struct inode *inode, struct file *filep)
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{
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struct uacce_mm *uacce_mm = NULL;
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struct uacce_device *uacce;
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struct uacce_queue *q;
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int ret = 0;
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@ -205,21 +135,16 @@ static int uacce_fops_open(struct inode *inode, struct file *filep)
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if (!q)
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return -ENOMEM;
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mutex_lock(&uacce->mm_lock);
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uacce_mm = uacce_mm_get(uacce, q, current->mm);
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mutex_unlock(&uacce->mm_lock);
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if (!uacce_mm) {
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ret = -ENOMEM;
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ret = uacce_bind_queue(uacce, q);
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if (ret)
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goto out_with_mem;
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}
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q->uacce = uacce;
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q->uacce_mm = uacce_mm;
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if (uacce->ops->get_queue) {
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ret = uacce->ops->get_queue(uacce, uacce_mm->pasid, q);
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ret = uacce->ops->get_queue(uacce, q->pasid, q);
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if (ret < 0)
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goto out_with_mm;
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goto out_with_bond;
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}
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init_waitqueue_head(&q->wait);
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@ -227,12 +152,14 @@ static int uacce_fops_open(struct inode *inode, struct file *filep)
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uacce->inode = inode;
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q->state = UACCE_Q_INIT;
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mutex_lock(&uacce->queues_lock);
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list_add(&q->list, &uacce->queues);
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mutex_unlock(&uacce->queues_lock);
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return 0;
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out_with_mm:
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mutex_lock(&uacce->mm_lock);
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uacce_mm_put(q);
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mutex_unlock(&uacce->mm_lock);
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out_with_bond:
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uacce_unbind_queue(q);
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out_with_mem:
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kfree(q);
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return ret;
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@ -241,14 +168,12 @@ out_with_mem:
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static int uacce_fops_release(struct inode *inode, struct file *filep)
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{
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struct uacce_queue *q = filep->private_data;
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struct uacce_device *uacce = q->uacce;
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mutex_lock(&q->uacce->queues_lock);
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list_del(&q->list);
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mutex_unlock(&q->uacce->queues_lock);
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uacce_put_queue(q);
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mutex_lock(&uacce->mm_lock);
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uacce_mm_put(q);
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mutex_unlock(&uacce->mm_lock);
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uacce_unbind_queue(q);
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kfree(q);
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return 0;
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@ -513,8 +438,8 @@ struct uacce_device *uacce_alloc(struct device *parent,
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if (ret < 0)
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goto err_with_uacce;
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INIT_LIST_HEAD(&uacce->mm_list);
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mutex_init(&uacce->mm_lock);
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INIT_LIST_HEAD(&uacce->queues);
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mutex_init(&uacce->queues_lock);
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device_initialize(&uacce->dev);
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uacce->dev.devt = MKDEV(MAJOR(uacce_devt), uacce->dev_id);
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uacce->dev.class = uacce_class;
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@ -561,8 +486,7 @@ EXPORT_SYMBOL_GPL(uacce_register);
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*/
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void uacce_remove(struct uacce_device *uacce)
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{
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struct uacce_mm *uacce_mm;
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struct uacce_queue *q;
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struct uacce_queue *q, *next_q;
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if (!uacce)
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return;
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@ -574,24 +498,12 @@ void uacce_remove(struct uacce_device *uacce)
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unmap_mapping_range(uacce->inode->i_mapping, 0, 0, 1);
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/* ensure no open queue remains */
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mutex_lock(&uacce->mm_lock);
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list_for_each_entry(uacce_mm, &uacce->mm_list, list) {
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/*
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* We don't take the uacce_mm->lock here. Since we hold the
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* device's mm_lock, no queue can be added to or removed from
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* this uacce_mm. We may run concurrently with mm_exit, but
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* uacce_put_queue() is serialized and iommu_sva_unbind_device()
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* waits for the lock that mm_exit is holding.
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*/
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list_for_each_entry(q, &uacce_mm->queues, list)
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uacce_put_queue(q);
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if (uacce->flags & UACCE_DEV_SVA) {
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iommu_sva_unbind_device(uacce_mm->handle);
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uacce_mm->handle = NULL;
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}
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mutex_lock(&uacce->queues_lock);
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list_for_each_entry_safe(q, next_q, &uacce->queues, list) {
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uacce_put_queue(q);
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uacce_unbind_queue(q);
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}
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mutex_unlock(&uacce->mm_lock);
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mutex_unlock(&uacce->queues_lock);
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/* disable sva now since no opened queues */
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if (uacce->flags & UACCE_DEV_SVA)
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@ -68,19 +68,21 @@ enum uacce_q_state {
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* @uacce: pointer to uacce
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* @priv: private pointer
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* @wait: wait queue head
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* @list: index into uacce_mm
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* @uacce_mm: the corresponding mm
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* @list: index into uacce queues list
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* @qfrs: pointer of qfr regions
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* @state: queue state machine
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* @pasid: pasid associated to the mm
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* @handle: iommu_sva handle returned by iommu_sva_bind_device()
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*/
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struct uacce_queue {
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struct uacce_device *uacce;
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void *priv;
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wait_queue_head_t wait;
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struct list_head list;
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struct uacce_mm *uacce_mm;
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struct uacce_qfile_region *qfrs[UACCE_MAX_REGION];
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enum uacce_q_state state;
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int pasid;
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struct iommu_sva *handle;
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};
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/**
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@ -96,8 +98,8 @@ struct uacce_queue {
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* @cdev: cdev of the uacce
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* @dev: dev of the uacce
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* @priv: private pointer of the uacce
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* @mm_list: list head of uacce_mm->list
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* @mm_lock: lock for mm_list
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* @queues: list of queues
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* @queues_lock: lock for queues list
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* @inode: core vfs
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*/
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struct uacce_device {
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@ -112,27 +114,9 @@ struct uacce_device {
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struct cdev *cdev;
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struct device dev;
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void *priv;
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struct list_head mm_list;
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struct mutex mm_lock;
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struct inode *inode;
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};
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/**
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* struct uacce_mm - keep track of queues bound to a process
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* @list: index into uacce_device
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* @queues: list of queues
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* @mm: the mm struct
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* @lock: protects the list of queues
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* @pasid: pasid of the uacce_mm
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* @handle: iommu_sva handle return from iommu_sva_bind_device
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*/
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struct uacce_mm {
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struct list_head list;
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struct list_head queues;
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struct mm_struct *mm;
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struct mutex lock;
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int pasid;
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struct iommu_sva *handle;
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struct mutex queues_lock;
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struct inode *inode;
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};
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#if IS_ENABLED(CONFIG_UACCE)
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