dmaengine: mv_xor_v2: Get rid of msi_desc abuse

Storing a pointer to the MSI descriptor just to keep track of the Linux
interrupt number is daft. Use msi_get_virq() instead.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20211210221814.970099984@linutronix.de

drivers/dma/mv_xor_v2.c

@@ -149,7 +149,7 @@ struct mv_xor_v2_descriptor {
  * @desc_size: HW descriptor size
  * @npendings: number of pending descriptors (for which tx_submit has
  * @hw_queue_idx: HW queue index
- * @msi_desc: local interrupt descriptor information
+ * @irq: The Linux interrupt number
  * been called, but not yet issue_pending)
  */
 struct mv_xor_v2_device {
@@ -168,7 +168,7 @@ struct mv_xor_v2_device {
 	int desc_size;
 	unsigned int npendings;
 	unsigned int hw_queue_idx;
-	struct msi_desc *msi_desc;
+	unsigned int irq;
 };
 
 /**
@@ -718,7 +718,6 @@ static int mv_xor_v2_probe(struct platform_device *pdev)
 	int i, ret = 0;
 	struct dma_device *dma_dev;
 	struct mv_xor_v2_sw_desc *sw_desc;
-	struct msi_desc *msi_desc;
 
 	BUILD_BUG_ON(sizeof(struct mv_xor_v2_descriptor) !=
 		     MV_XOR_V2_EXT_DESC_SIZE);
@@ -770,14 +769,9 @@ static int mv_xor_v2_probe(struct platform_device *pdev)
 	if (ret)
 		goto disable_clk;
 
-	msi_desc = first_msi_entry(&pdev->dev);
-	if (!msi_desc) {
-		ret = -ENODEV;
-		goto free_msi_irqs;
-	}
-	xor_dev->msi_desc = msi_desc;
+	xor_dev->irq = msi_get_virq(&pdev->dev, 0);
 
-	ret = devm_request_irq(&pdev->dev, msi_desc->irq,
+	ret = devm_request_irq(&pdev->dev, xor_dev->irq,
 			       mv_xor_v2_interrupt_handler, 0,
 			       dev_name(&pdev->dev), xor_dev);
 	if (ret)
@@ -892,7 +886,7 @@ static int mv_xor_v2_remove(struct platform_device *pdev)
 			  xor_dev->desc_size * MV_XOR_V2_DESC_NUM,
 			  xor_dev->hw_desq_virt, xor_dev->hw_desq);
 
-	devm_free_irq(&pdev->dev, xor_dev->msi_desc->irq, xor_dev);
+	devm_free_irq(&pdev->dev, xor_dev->irq, xor_dev);
 
 	platform_msi_domain_free_irqs(&pdev->dev);