3 files changed, 79 insertions, 18 deletions

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 78d2dc5e9bd8..d255bb016c4d 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -186,8 +186,6 @@ int idxd_wq_alloc_resources(struct idxd_wq *wq)
 		desc->id = i;
 		desc->wq = wq;
 		desc->cpu = -1;
-		dma_async_tx_descriptor_init(&desc->txd, &wq->dma_chan);
-		desc->txd.tx_submit = idxd_dma_tx_submit;
 	}
 
 	return 0;
diff --git a/drivers/dma/idxd/dma.c b/drivers/dma/idxd/dma.c
index a15e50126434..77439b645044 100644
--- a/drivers/dma/idxd/dma.c
+++ b/drivers/dma/idxd/dma.c
@@ -14,7 +14,10 @@
 
 static inline struct idxd_wq *to_idxd_wq(struct dma_chan *c)
 {
-	return container_of(c, struct idxd_wq, dma_chan);
+	struct idxd_dma_chan *idxd_chan;
+
+	idxd_chan = container_of(c, struct idxd_dma_chan, chan);
+	return idxd_chan->wq;
 }
 
 void idxd_dma_complete_txd(struct idxd_desc *desc,
@@ -135,7 +138,7 @@ static void idxd_dma_issue_pending(struct dma_chan *dma_chan)
 {
 }
 
-dma_cookie_t idxd_dma_tx_submit(struct dma_async_tx_descriptor *tx)
+static dma_cookie_t idxd_dma_tx_submit(struct dma_async_tx_descriptor *tx)
 {
 	struct dma_chan *c = tx->chan;
 	struct idxd_wq *wq = to_idxd_wq(c);
@@ -156,14 +159,25 @@ dma_cookie_t idxd_dma_tx_submit(struct dma_async_tx_descriptor *tx)
 
 static void idxd_dma_release(struct dma_device *device)
 {
+	struct idxd_dma_dev *idxd_dma = container_of(device, struct idxd_dma_dev, dma);
+
+	kfree(idxd_dma);
 }
 
 int idxd_register_dma_device(struct idxd_device *idxd)
 {
-	struct dma_device *dma = &idxd->dma_dev;
+	struct idxd_dma_dev *idxd_dma;
+	struct dma_device *dma;
+	struct device *dev = &idxd->pdev->dev;
+	int rc;
 
+	idxd_dma = kzalloc_node(sizeof(*idxd_dma), GFP_KERNEL, dev_to_node(dev));
+	if (!idxd_dma)
+		return -ENOMEM;
+
+	dma = &idxd_dma->dma;
 	INIT_LIST_HEAD(&dma->channels);
-	dma->dev = &idxd->pdev->dev;
+	dma->dev = dev;
 
 	dma_cap_set(DMA_PRIVATE, dma->cap_mask);
 	dma_cap_set(DMA_COMPLETION_NO_ORDER, dma->cap_mask);
@@ -179,35 +193,72 @@ int idxd_register_dma_device(struct idxd_device *idxd)
 	dma->device_alloc_chan_resources = idxd_dma_alloc_chan_resources;
 	dma->device_free_chan_resources = idxd_dma_free_chan_resources;
 
-	return dma_async_device_register(&idxd->dma_dev);
+	rc = dma_async_device_register(dma);
+	if (rc < 0) {
+		kfree(idxd_dma);
+		return rc;
+	}
+
+	idxd_dma->idxd = idxd;
+	/*
+	 * This pointer is protected by the refs taken by the dma_chan. It will remain valid
+	 * as long as there are outstanding channels.
+	 */
+	idxd->idxd_dma = idxd_dma;
+	return 0;
 }
 
 void idxd_unregister_dma_device(struct idxd_device *idxd)
 {
-	dma_async_device_unregister(&idxd->dma_dev);
+	dma_async_device_unregister(&idxd->idxd_dma->dma);
 }
 
 int idxd_register_dma_channel(struct idxd_wq *wq)
 {
 	struct idxd_device *idxd = wq->idxd;
-	struct dma_device *dma = &idxd->dma_dev;
-	struct dma_chan *chan = &wq->dma_chan;
-	int rc;
+	struct dma_device *dma = &idxd->idxd_dma->dma;
+	struct device *dev = &idxd->pdev->dev;
+	struct idxd_dma_chan *idxd_chan;
+	struct dma_chan *chan;
+	int rc, i;
+
+	idxd_chan = kzalloc_node(sizeof(*idxd_chan), GFP_KERNEL, dev_to_node(dev));
+	if (!idxd_chan)
+		return -ENOMEM;
 
-	memset(&wq->dma_chan, 0, sizeof(struct dma_chan));
+	chan = &idxd_chan->chan;
 	chan->device = dma;
 	list_add_tail(&chan->device_node, &dma->channels);
+
+	for (i = 0; i < wq->num_descs; i++) {
+		struct idxd_desc *desc = wq->descs[i];
+
+		dma_async_tx_descriptor_init(&desc->txd, chan);
+		desc->txd.tx_submit = idxd_dma_tx_submit;
+	}
+
 	rc = dma_async_device_channel_register(dma, chan);
-	if (rc < 0)
+	if (rc < 0) {
+		kfree(idxd_chan);
 		return rc;
+	}
+
+	wq->idxd_chan = idxd_chan;
+	idxd_chan->wq = wq;
+	get_device(&wq->conf_dev);
 
 	return 0;
 }
 
 void idxd_unregister_dma_channel(struct idxd_wq *wq)
 {
-	struct dma_chan *chan = &wq->dma_chan;
+	struct idxd_dma_chan *idxd_chan = wq->idxd_chan;
+	struct dma_chan *chan = &idxd_chan->chan;
+	struct idxd_dma_dev *idxd_dma = wq->idxd->idxd_dma;
 
-	dma_async_device_channel_unregister(&wq->idxd->dma_dev, chan);
+	dma_async_device_channel_unregister(&idxd_dma->dma, chan);
 	list_del(&chan->device_node);
+	kfree(wq->idxd_chan);
+	wq->idxd_chan = NULL;
+	put_device(&wq->conf_dev);
 }
diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index 76014c14f473..80e534680c9a 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -14,6 +14,9 @@
 
 extern struct kmem_cache *idxd_desc_pool;
 
+struct idxd_device;
+struct idxd_wq;
+
 #define IDXD_REG_TIMEOUT	50
 #define IDXD_DRAIN_TIMEOUT	5000
 
@@ -96,6 +99,11 @@ enum idxd_complete_type {
 	IDXD_COMPLETE_DEV_FAIL,
 };
 
+struct idxd_dma_chan {
+	struct dma_chan chan;
+	struct idxd_wq *wq;
+};
+
 struct idxd_wq {
 	void __iomem *portal;
 	struct device conf_dev;
@@ -125,7 +133,7 @@ struct idxd_wq {
 	int compls_size;
 	struct idxd_desc **descs;
 	struct sbitmap_queue sbq;
-	struct dma_chan dma_chan;
+	struct idxd_dma_chan *idxd_chan;
 	char name[WQ_NAME_SIZE + 1];
 	u64 max_xfer_bytes;
 	u32 max_batch_size;
@@ -162,6 +170,11 @@ enum idxd_device_flag {
 	IDXD_FLAG_PASID_ENABLED,
 };
 
+struct idxd_dma_dev {
+	struct idxd_device *idxd;
+	struct dma_device dma;
+};
+
 struct idxd_device {
 	enum idxd_type type;
 	struct device conf_dev;
@@ -210,7 +223,7 @@ struct idxd_device {
 	int num_wq_irqs;
 	struct idxd_irq_entry *irq_entries;
 
-	struct dma_device dma_dev;
+	struct idxd_dma_dev *idxd_dma;
 	struct workqueue_struct *wq;
 	struct work_struct work;
 };
@@ -363,7 +376,6 @@ void idxd_unregister_dma_channel(struct idxd_wq *wq);
 void idxd_parse_completion_status(u8 status, enum dmaengine_tx_result *res);
 void idxd_dma_complete_txd(struct idxd_desc *desc,
 			   enum idxd_complete_type comp_type);
-dma_cookie_t idxd_dma_tx_submit(struct dma_async_tx_descriptor *tx);
 
 /* cdev */
 int idxd_cdev_register(void);