PCI: Deprecate pcim_iomap_regions() in favor of pcim_iomap_region()

pcim_iomap_regions() is a complicated function that uses a bit mask to
determine the BARs the user wishes to request and ioremap. Almost all users
only ever set a single bit in that mask, making that mechanism
questionable.

pcim_iomap_region() is now available as a more simple replacement.

Make pcim_iomap_region() a public function.

Mark pcim_iomap_regions() as deprecated.

Link: https://lore.kernel.org/r/20240807083018.8734-2-pstanner@redhat.com
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/devres.c

@@ -728,7 +728,7 @@ EXPORT_SYMBOL(pcim_iounmap);
  * Mapping and region will get automatically released on driver detach. If
  * desired, release manually only with pcim_iounmap_region().
  */
-static void __iomem *pcim_iomap_region(struct pci_dev *pdev, int bar,
+void __iomem *pcim_iomap_region(struct pci_dev *pdev, int bar,
 				       const char *name)
 {
 	int ret;
@@ -761,6 +761,7 @@ static void __iomem *pcim_iomap_region(struct pci_dev *pdev, int bar,
 
 	return IOMEM_ERR_PTR(ret);
 }
+EXPORT_SYMBOL(pcim_iomap_region);
 
 /**
  * pcim_iounmap_region - Unmap and release a PCI BAR
@@ -783,14 +784,17 @@ static void pcim_iounmap_region(struct pci_dev *pdev, int bar)
 }
 
 /**
- * pcim_iomap_regions - Request and iomap PCI BARs
+ * pcim_iomap_regions - Request and iomap PCI BARs (DEPRECATED)
  * @pdev: PCI device to map IO resources for
  * @mask: Mask of BARs to request and iomap
  * @name: Name associated with the requests
  *
  * Returns: 0 on success, negative error code on failure.
  *
  * Request and iomap regions specified by @mask.
+ *
+ * This function is DEPRECATED. Do not use it in new code.
+ * Use pcim_iomap_region() instead.
  */
 int pcim_iomap_regions(struct pci_dev *pdev, int mask, const char *name)
 {

include/linux/pci.h

@@ -2290,6 +2290,8 @@ static inline void pci_fixup_device(enum pci_fixup_pass pass,
 #endif
 
 void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen);
+void __iomem *pcim_iomap_region(struct pci_dev *pdev, int bar,
+				const char *name);
 void pcim_iounmap(struct pci_dev *pdev, void __iomem *addr);
 void __iomem * const *pcim_iomap_table(struct pci_dev *pdev);
 int pcim_request_region(struct pci_dev *pdev, int bar, const char *name);