PCI: Add helpers to request/release memory and I/O regions

Add helpers to request and release a device's memory or I/O regions.

With these helpers in place, one does not need to select a device's memory
or I/O regions with pci_select_bars() prior to requesting or releasing
them.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

include/linux/pci.h

@@ -1402,6 +1402,34 @@ typedef int (*arch_set_vga_state_t)(struct pci_dev *pdev, bool decode,
 		      unsigned int command_bits, u32 flags);
 void pci_register_set_vga_state(arch_set_vga_state_t func);
 
+static inline int
+pci_request_io_regions(struct pci_dev *pdev, const char *name)
+{
+	return pci_request_selected_regions(pdev,
+			    pci_select_bars(pdev, IORESOURCE_IO), name);
+}
+
+static inline void
+pci_release_io_regions(struct pci_dev *pdev)
+{
+	return pci_release_selected_regions(pdev,
+			    pci_select_bars(pdev, IORESOURCE_IO));
+}
+
+static inline int
+pci_request_mem_regions(struct pci_dev *pdev, const char *name)
+{
+	return pci_request_selected_regions(pdev,
+			    pci_select_bars(pdev, IORESOURCE_MEM), name);
+}
+
+static inline void
+pci_release_mem_regions(struct pci_dev *pdev)
+{
+	return pci_release_selected_regions(pdev,
+			    pci_select_bars(pdev, IORESOURCE_MEM));
+}
+
 #else /* CONFIG_PCI is not enabled */
 
 static inline void pci_set_flags(int flags) { }