genirq/msi: Remove the original sysfs interfaces

No more users. Refactor the core code accordingly and move the global
interface under CONFIG_PCI_MSI_ARCH_FALLBACKS.

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/20211210221814.168362229@linutronix.de

include/linux/msi.h

@@ -249,22 +249,10 @@ void pci_msi_unmask_irq(struct irq_data *data);
 #ifdef CONFIG_SYSFS
 int msi_device_populate_sysfs(struct device *dev);
 void msi_device_destroy_sysfs(struct device *dev);
-
-const struct attribute_group **msi_populate_sysfs(struct device *dev);
-void msi_destroy_sysfs(struct device *dev,
-		       const struct attribute_group **msi_irq_groups);
-#else
+#else /* CONFIG_SYSFS */
 static inline int msi_device_populate_sysfs(struct device *dev) { return 0; }
 static inline void msi_device_destroy_sysfs(struct device *dev) { }
-
-static inline const struct attribute_group **msi_populate_sysfs(struct device *dev)
-{
-	return NULL;
-}
-static inline void msi_destroy_sysfs(struct device *dev, const struct attribute_group **msi_irq_groups)
-{
-}
-#endif
+#endif /* !CONFIG_SYSFS */
 
 /*
  * The arch hooks to setup up msi irqs. Default functions are implemented
@@ -279,7 +267,7 @@ int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc);
 void arch_teardown_msi_irq(unsigned int irq);
 int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
 void arch_teardown_msi_irqs(struct pci_dev *dev);
-#endif
+#endif /* CONFIG_PCI_MSI_ARCH_FALLBACKS */
 
 /*
  * The restore hook is still available even for fully irq domain based

kernel/irq/msi.c

@@ -118,12 +118,8 @@ static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
 /**
  * msi_populate_sysfs - Populate msi_irqs sysfs entries for devices
  * @dev:	The device(PCI, platform etc) who will get sysfs entries
- *
- * Return attribute_group ** so that specific bus MSI can save it to
- * somewhere during initilizing msi irqs. If devices has no MSI irq,
- * return NULL; if it fails to populate sysfs, return ERR_PTR
  */
-const struct attribute_group **msi_populate_sysfs(struct device *dev)
+static const struct attribute_group **msi_populate_sysfs(struct device *dev)
 {
 	const struct attribute_group **msi_irq_groups;
 	struct attribute **msi_attrs, *msi_attr;
@@ -213,42 +209,33 @@ int msi_device_populate_sysfs(struct device *dev)
 	return 0;
 }
 
-/**
- * msi_destroy_sysfs - Destroy msi_irqs sysfs entries for devices
- * @dev:		The device(PCI, platform etc) who will remove sysfs entries
- * @msi_irq_groups:	attribute_group for device msi_irqs entries
- */
-void msi_destroy_sysfs(struct device *dev, const struct attribute_group **msi_irq_groups)
-{
-	struct device_attribute *dev_attr;
-	struct attribute **msi_attrs;
-	int count = 0;
-
-	if (msi_irq_groups) {
-		sysfs_remove_groups(&dev->kobj, msi_irq_groups);
-		msi_attrs = msi_irq_groups[0]->attrs;
-		while (msi_attrs[count]) {
-			dev_attr = container_of(msi_attrs[count],
-					struct device_attribute, attr);
-			kfree(dev_attr->attr.name);
-			kfree(dev_attr);
-			++count;
-		}
-		kfree(msi_attrs);
-		kfree(msi_irq_groups[0]);
-		kfree(msi_irq_groups);
-	}
-}
-
 /**
  * msi_device_destroy_sysfs - Destroy msi_irqs sysfs entries for a device
  * @dev:		The device (PCI, platform etc) for which to remove
  *			sysfs entries
  */
 void msi_device_destroy_sysfs(struct device *dev)
 {
-	msi_destroy_sysfs(dev, dev->msi.data->attrs);
+	const struct attribute_group **msi_irq_groups = dev->msi.data->attrs;
+	struct device_attribute *dev_attr;
+	struct attribute **msi_attrs;
+	int count = 0;
+
 	dev->msi.data->attrs = NULL;
+	if (!msi_irq_groups)
+		return;
+
+	sysfs_remove_groups(&dev->kobj, msi_irq_groups);
+	msi_attrs = msi_irq_groups[0]->attrs;
+	while (msi_attrs[count]) {
+		dev_attr = container_of(msi_attrs[count], struct device_attribute, attr);
+		kfree(dev_attr->attr.name);
+		kfree(dev_attr);
+		++count;
+	}
+	kfree(msi_attrs);
+	kfree(msi_irq_groups[0]);
+	kfree(msi_irq_groups);
 }
 #endif