PCI/MSI: Move pci_disable_msix() to api.c

To disentangle the maze in msi.c, all exported device-driver MSI APIs are
now to be grouped in one file, api.c.

Move pci_disable_msix() and make its kernel-doc comprehensive.

Signed-off-by: Ahmed S. Darwish <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Bjorn Helgaas <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: Ahmed S. Darwish

drivers/pci/msi/api.c

@@ -111,6 +111,30 @@ int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
 }
 EXPORT_SYMBOL(pci_enable_msix_range);
 
+/**
+ * pci_disable_msix() - Disable MSI-X interrupt mode on device
+ * @dev: the PCI device to operate on
+ *
+ * Legacy device driver API to disable MSI-X interrupt mode on device,
+ * free earlier-allocated interrupt vectors, and restore INTx.
+ * The PCI device Linux IRQ (@dev->irq) is restored to its default pin
+ * assertion IRQ. This is the cleanup pair of pci_enable_msix_range().
+ *
+ * NOTE: The newer pci_alloc_irq_vectors() / pci_free_irq_vectors() API
+ * pair should, in general, be used instead.
+ */
+void pci_disable_msix(struct pci_dev *dev)
+{
+	if (!pci_msi_enabled() || !dev || !dev->msix_enabled)
+		return;
+
+	msi_lock_descs(&dev->dev);
+	pci_msix_shutdown(dev);
+	pci_free_msi_irqs(dev);
+	msi_unlock_descs(&dev->dev);
+}
+EXPORT_SYMBOL(pci_disable_msix);
+
 /**
  * pci_alloc_irq_vectors() - Allocate multiple device interrupt vectors
  * @dev:      the PCI device to operate on

drivers/pci/msi/msi.c

@@ -736,7 +736,7 @@ static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
 	return msix_capability_init(dev, entries, nvec, affd);
 }
 
-static void pci_msix_shutdown(struct pci_dev *dev)
+void pci_msix_shutdown(struct pci_dev *dev)
 {
 	struct msi_desc *desc;
 
@@ -758,18 +758,6 @@ static void pci_msix_shutdown(struct pci_dev *dev)
 	pcibios_alloc_irq(dev);
 }
 
-void pci_disable_msix(struct pci_dev *dev)
-{
-	if (!pci_msi_enable || !dev || !dev->msix_enabled)
-		return;
-
-	msi_lock_descs(&dev->dev);
-	pci_msix_shutdown(dev);
-	pci_free_msi_irqs(dev);
-	msi_unlock_descs(&dev->dev);
-}
-EXPORT_SYMBOL(pci_disable_msix);
-
 int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
 			   struct irq_affinity *affd)
 {

drivers/pci/msi/msi.h

@@ -86,6 +86,7 @@ static inline __attribute_const__ u32 msi_multi_mask(struct msi_desc *desc)
 
 /* MSI internal functions invoked from the public APIs */
 void pci_msi_shutdown(struct pci_dev *dev);
+void pci_msix_shutdown(struct pci_dev *dev);
 void pci_free_msi_irqs(struct pci_dev *dev);
 int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec, struct irq_affinity *affd);
 int __pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, int minvec,