platform-msi: Factor out allocation/free of private data

As we're going to have multiple paths to allocate/free the
platform-msi private data, factor this out into separate
utility functions.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

drivers/base/platform-msi.c

@@ -189,6 +189,52 @@ struct irq_domain *platform_msi_create_irq_domain(struct fwnode_handle *fwnode,
 	return domain;
 }
 
+static struct platform_msi_priv_data *
+platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec,
+			     irq_write_msi_msg_t write_msi_msg)
+{
+	struct platform_msi_priv_data *datap;
+	/*
+	 * Limit the number of interrupts to 256 per device. Should we
+	 * need to bump this up, DEV_ID_SHIFT should be adjusted
+	 * accordingly (which would impact the max number of MSI
+	 * capable devices).
+	 */
+	if (!dev->msi_domain || !write_msi_msg || !nvec || nvec > MAX_DEV_MSIS)
+		return ERR_PTR(-EINVAL);
+
+	if (dev->msi_domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) {
+		dev_err(dev, "Incompatible msi_domain, giving up\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	/* Already had a helping of MSI? Greed... */
+	if (!list_empty(dev_to_msi_list(dev)))
+		return ERR_PTR(-EBUSY);
+
+	datap = kzalloc(sizeof(*datap), GFP_KERNEL);
+	if (!datap)
+		return ERR_PTR(-ENOMEM);
+
+	datap->devid = ida_simple_get(&platform_msi_devid_ida,
+				      0, 1 << DEV_ID_SHIFT, GFP_KERNEL);
+	if (datap->devid < 0) {
+		int err = datap->devid;
+		kfree(datap);
+		return ERR_PTR(err);
+	}
+
+	datap->write_msg = write_msi_msg;
+
+	return datap;
+}
+
+static void platform_msi_free_priv_data(struct platform_msi_priv_data *data)
+{
+	ida_simple_remove(&platform_msi_devid_ida, data->devid);
+	kfree(data);
+}
+
 /**
  * platform_msi_domain_alloc_irqs - Allocate MSI interrupts for @dev
  * @dev:		The device for which to allocate interrupts
@@ -204,40 +250,13 @@ int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec,
 	struct platform_msi_priv_data *priv_data;
 	int err;
 
-	/*
+	priv_data = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
-	 * Limit the number of interrupts to 256 per device. Should we
+	if (IS_ERR(priv_data))
-	 * need to bump this up, DEV_ID_SHIFT should be adjusted
+		return PTR_ERR(priv_data);
-	 * accordingly (which would impact the max number of MSI
-	 * capable devices).
-	 */
-	if (!dev->msi_domain || !write_msi_msg || !nvec || nvec > MAX_DEV_MSIS)
-		return -EINVAL;
-
-	if (dev->msi_domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) {
-		dev_err(dev, "Incompatible msi_domain, giving up\n");
-		return -EINVAL;
-	}
-
-	/* Already had a helping of MSI? Greed... */
-	if (!list_empty(dev_to_msi_list(dev)))
-		return -EBUSY;
-
-	priv_data = kzalloc(sizeof(*priv_data), GFP_KERNEL);
-	if (!priv_data)
-		return -ENOMEM;
-
-	priv_data->devid = ida_simple_get(&platform_msi_devid_ida,
-					  0, 1 << DEV_ID_SHIFT, GFP_KERNEL);
-	if (priv_data->devid < 0) {
-		err = priv_data->devid;
-		goto out_free_data;
-	}
-
-	priv_data->write_msg = write_msi_msg;
 
 	err = platform_msi_alloc_descs(dev, nvec, priv_data);
 	if (err)
-		goto out_free_id;
+		goto out_free_priv_data;
 
 	err = msi_domain_alloc_irqs(dev->msi_domain, dev, nvec);
 	if (err)
@@ -247,10 +266,8 @@ int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec,
 
 out_free_desc:
 	platform_msi_free_descs(dev, 0, nvec);
-out_free_id:
+out_free_priv_data:
-	ida_simple_remove(&platform_msi_devid_ida, priv_data->devid);
+	platform_msi_free_priv_data(priv_data);
-out_free_data:
-	kfree(priv_data);
 
 	return err;
 }
@@ -261,16 +278,11 @@ out_free_data:
  */
 void platform_msi_domain_free_irqs(struct device *dev)
 {
-	struct msi_desc *desc;
+	if (!list_empty(dev_to_msi_list(dev))) {
+		struct msi_desc *desc;
 
-	desc = first_msi_entry(dev);
+		desc = first_msi_entry(dev);
-	if (desc) {
+		platform_msi_free_priv_data(desc->platform.msi_priv_data);
-		struct platform_msi_priv_data *data;
-
-		data = desc->platform.msi_priv_data;
-
-		ida_simple_remove(&platform_msi_devid_ida, data->devid);
-		kfree(data);
 	}
 
 	msi_domain_free_irqs(dev->msi_domain, dev);