genirq/msi: Move descriptor list to struct msi_device_data

It's only required when MSI is in use.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210747.650487479@linutronix.de

drivers/base/core.c

@@ -2874,9 +2874,6 @@ void device_initialize(struct device *dev)
 	INIT_LIST_HEAD(&dev->devres_head);
 	device_pm_init(dev);
 	set_dev_node(dev, NUMA_NO_NODE);
-#ifdef CONFIG_GENERIC_MSI_IRQ
-	INIT_LIST_HEAD(&dev->msi_list);
-#endif
 	INIT_LIST_HEAD(&dev->links.consumers);
 	INIT_LIST_HEAD(&dev->links.suppliers);
 	INIT_LIST_HEAD(&dev->links.defer_sync);

include/linux/device.h

@@ -423,7 +423,6 @@ struct dev_msi_info {
  * @pins:	For device pin management.
  *		See Documentation/driver-api/pin-control.rst for details.
  * @msi:	MSI related data
- * @msi_list:	Hosts MSI descriptors
  * @numa_node:	NUMA node this device is close to.
  * @dma_ops:    DMA mapping operations for this device.
  * @dma_mask:	Dma mask (if dma'ble device).
@@ -519,9 +518,6 @@ struct device {
 	struct dev_pin_info	*pins;
 #endif
 	struct dev_msi_info	msi;
-#ifdef CONFIG_GENERIC_MSI_IRQ
-	struct list_head	msi_list;
-#endif
 #ifdef CONFIG_DMA_OPS
 	const struct dma_map_ops *dma_ops;
 #endif

include/linux/msi.h

@@ -144,11 +144,13 @@ struct msi_desc {
  * @properties:		MSI properties which are interesting to drivers
  * @attrs:		Pointer to the sysfs attribute group
  * @platform_data:	Platform-MSI specific data
+ * @list:		List of MSI descriptors associated to the device
  */
 struct msi_device_data {
 	unsigned long			properties;
 	const struct attribute_group    **attrs;
 	struct platform_msi_priv_data	*platform_data;
+	struct list_head		list;
 };
 
 int msi_setup_device_data(struct device *dev);
@@ -157,7 +159,7 @@ unsigned int msi_get_virq(struct device *dev, unsigned int index);
 
 /* Helpers to hide struct msi_desc implementation details */
 #define msi_desc_to_dev(desc)		((desc)->dev)
-#define dev_to_msi_list(dev)		(&(dev)->msi_list)
+#define dev_to_msi_list(dev)		(&(dev)->msi.data->list)
 #define first_msi_entry(dev)		\
 	list_first_entry(dev_to_msi_list((dev)), struct msi_desc, list)
 #define for_each_msi_entry(desc, dev)	\

kernel/irq/msi.c

@@ -75,7 +75,9 @@ EXPORT_SYMBOL_GPL(get_cached_msi_msg);
 
 static void msi_device_data_release(struct device *dev, void *res)
 {
-	WARN_ON_ONCE(!list_empty(&dev->msi_list));
+	struct msi_device_data *md = res;
+
+	WARN_ON_ONCE(!list_empty(&md->list));
 	dev->msi.data = NULL;
 }
 
@@ -100,6 +102,7 @@ int msi_setup_device_data(struct device *dev)
 	if (!md)
 		return -ENOMEM;
 
+	INIT_LIST_HEAD(&md->list);
 	dev->msi.data = md;
 	devres_add(dev, md);
 	return 0;