Re: [PATCH 1/3] lib: add NO_GENERIC_PCI_IOPORT_MAP

[Arnd Bergmann <arnd@arndb.de>]

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