Re: [PATCH v9 12/12] PCI: Introduce pci_remap_iospace() for remapping PCI I/O bus resources into CPU space

Rob Herring
2014-08-22T04:16:39Z

On Tue, Aug 12, 2014 at 11:25 AM, Liviu Dudau <Liviu.Dudau@arm.com> wrote:
> Introduce a default implementation for remapping PCI bus I/O resources
> onto the CPU address space. Architectures with special needs may
> provide their own version, but most should be able to use this one.
>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>

Reviewed-by: Rob Herring <robh@kernel.org>

However, I would like to see ARM pci_ioremap_io converted over to this function.

Rob

> ---
> drivers/pci/pci.c | 33 +++++++++++++++++++++++++++++++++
> include/linux/pci.h | 3 +++
> 2 files changed, 36 insertions(+)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 29d1775..76d21b6 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -2707,6 +2707,39 @@ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
> }
> EXPORT_SYMBOL(pci_request_regions_exclusive);
>
> +/**
> + * pci_remap_iospace - Remap the memory mapped I/O space
> + * @res: Resource describing the I/O space
> + * @phys_addr: physical address where the range will be mapped.
> + *
> + * Remap the memory mapped I/O space described by the @res
> + * into the CPU physical address space. Only architectures
> + * that have memory mapped IO defined (and hence PCI_IOBASE)
> + * should call this function.
> + */
> +int __weak pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
> +{
> + int err = -ENODEV;
> +
> +#ifdef PCI_IOBASE
> + if (!(res->flags & IORESOURCE_IO))
> + return -EINVAL;
> +
> + if (res->end > IO_SPACE_LIMIT)
> + return -EINVAL;
> +
> + err = ioremap_page_range(res->start + (unsigned long)PCI_IOBASE,
> + res->end + 1 + (unsigned long)PCI_IOBASE,
> + phys_addr, pgprot_device(PAGE_KERNEL));
> +#else
> + /* this architecture does not have memory mapped I/O space,
> + so this function should never be called */
> + WARN_ON(1);
> +#endif
> +
> + return err;
> +}
> +
> static void __pci_set_master(struct pci_dev *dev, bool enable)
> {
> u16 old_cmd, cmd;
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index e1e0d80..988c2f5 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1098,6 +1098,9 @@ int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
> resource_size_t),
> void *alignf_data);
>
> +
> +int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr);
> +
> static inline dma_addr_t pci_bus_address(struct pci_dev *pdev, int bar)
> {
> struct pci_bus_region region;
> --
> 2.0.4
>
>
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