bus: fsl-mc-msi: Simplify MSI descriptor handling

Let the MSI irq domain code handle descriptor allocation and free.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210748.847219474@linutronix.de

drivers/bus/fsl-mc/fsl-mc-msi.c

@@ -170,6 +170,7 @@ struct irq_domain *fsl_mc_msi_create_irq_domain(struct fwnode_handle *fwnode,
 		fsl_mc_msi_update_dom_ops(info);
 	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
 		fsl_mc_msi_update_chip_ops(info);
+	info->flags |= MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS | MSI_FLAG_FREE_MSI_DESCS;
 
 	domain = msi_create_irq_domain(fwnode, info, parent);
 	if (domain)
@@ -210,45 +211,7 @@ struct irq_domain *fsl_mc_find_msi_domain(struct device *dev)
 	return msi_domain;
 }
 
-static void fsl_mc_msi_free_descs(struct device *dev)
-{
-	struct msi_desc *desc, *tmp;
-
-	list_for_each_entry_safe(desc, tmp, dev_to_msi_list(dev), list) {
-		list_del(&desc->list);
-		free_msi_entry(desc);
-	}
-}
-
-static int fsl_mc_msi_alloc_descs(struct device *dev, unsigned int irq_count)
-
-{
-	unsigned int i;
-	int error;
-	struct msi_desc *msi_desc;
-
-	for (i = 0; i < irq_count; i++) {
-		msi_desc = alloc_msi_entry(dev, 1, NULL);
-		if (!msi_desc) {
-			dev_err(dev, "Failed to allocate msi entry\n");
-			error = -ENOMEM;
-			goto cleanup_msi_descs;
-		}
-
-		msi_desc->msi_index = i;
-		INIT_LIST_HEAD(&msi_desc->list);
-		list_add_tail(&msi_desc->list, dev_to_msi_list(dev));
-	}
-
-	return 0;
-
-cleanup_msi_descs:
-	fsl_mc_msi_free_descs(dev);
-	return error;
-}
-
-int fsl_mc_msi_domain_alloc_irqs(struct device *dev,
-				 unsigned int irq_count)
+int fsl_mc_msi_domain_alloc_irqs(struct device *dev,  unsigned int irq_count)
 {
 	struct irq_domain *msi_domain;
 	int error;
@@ -261,28 +224,17 @@ int fsl_mc_msi_domain_alloc_irqs(struct device *dev,
 	if (error)
 		return error;
 
-	if (!list_empty(dev_to_msi_list(dev)))
+	if (msi_first_desc(dev, MSI_DESC_ALL))
 		return -EINVAL;
 
-	error = fsl_mc_msi_alloc_descs(dev, irq_count);
-	if (error < 0)
-		return error;
-
 	/*
 	 * NOTE: Calling this function will trigger the invocation of the
 	 * its_fsl_mc_msi_prepare() callback
 	 */
 	error = msi_domain_alloc_irqs(msi_domain, dev, irq_count);
 
-	if (error) {
+	if (error)
 		dev_err(dev, "Failed to allocate IRQs\n");
-		goto cleanup_msi_descs;
-	}
-
-	return 0;
-
-cleanup_msi_descs:
-	fsl_mc_msi_free_descs(dev);
 	return error;
 }
 
@@ -295,9 +247,4 @@ void fsl_mc_msi_domain_free_irqs(struct device *dev)
 		return;
 
 	msi_domain_free_irqs(msi_domain, dev);
-
-	if (list_empty(dev_to_msi_list(dev)))
-		return;
-
-	fsl_mc_msi_free_descs(dev);
 }