On Mon, Jan 30, 2012 at 03:51:46PM +0000, Arnd Bergmann wrote:

On Monday 30 January 2012, Michael S. Tsirkin wrote:

quoted

--- a/include/asm-generic/pci_iomap.h
+++ b/include/asm-generic/pci_iomap.h

@@ -15,6 +15,11 @@ struct pci_dev;
 #ifdef CONFIG_PCI
 /* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
 extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max);
+/* Create a virtual mapping cookie for a port on a given PCI device.
+ * Do not call this directly, it exists to make it easier for architectures
+ * to override. */
+extern void __iomem *__pci_ioport_map(struct pci_dev *dev, unsigned long port,
+                                     unsigned int nr);
 #else
 static inline void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max)
 {

index 4b0fdc2..1dfda29 100644
--- a/lib/pci_iomap.c
+++ b/lib/pci_iomap.c

@@ -9,6 +9,16 @@
 #include <linux/export.h>
 
 #ifdef CONFIG_PCI
+#ifndef CONFIG_NO_GENERIC_PCI_IOPORT_MAP
+/* Architectures can override ioport mapping while
+ * still using the rest of the generic infrastructure. */
+void __iomem *__pci_ioport_map(struct pci_dev *dev,
+                              unsigned long port,
+                              unsigned int nr)
+{
+       return ioport_map(port, nr);
+}
+#endif
 /**
  * pci_iomap - create a virtual mapping cookie for a PCI BAR
  * @dev: PCI device that owns the BAR

This looks correct, but it would be nicer to express this with an inline
function and keeping the new #ifdef to the header file, like

+/*
+ * Create a virtual mapping cookie for a port on a given PCI device.
+ * Do not call this directly, it exists to make it easier for architectures
+ * to override.
+ */
+#ifdef CONFIG_NO_GENERIC_PCI_IOPORT_MAP
+extern void __iomem *__pci_ioport_map(struct pci_dev *dev, unsigned long port,
+                                     unsigned int nr);
+#else
+static inline void __iomem *__pci_ioport_map(struct pci_dev *dev,
+                              unsigned long port, unsigned int nr)
+{
+       return ioport_map(port, nr);
+}
+#endif

	Arnd

It would be nicer in that it would
make the kernel a bit smaller for generic architectures
but this would need to go into a separate header:
it depends on io.h and io.h depends on pci_iomap.h.

Worth it?

-- 
MST