On Wed, Jan 14, 2015 at 07:27:54PM +0200, Michael S. Tsirkin wrote:
> Virtio drivers should map the part of the BAR they need, not necessarily
> all of it.
>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: linux-pci@xxxxxxxxxxxxxxx
> Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Sorry it took so long for me to notice these!
> ---
>
> Bjorn, can you please ack this for merging through the virtio tree?
>
> include/asm-generic/pci_iomap.h | 10 ++++++++++
> lib/pci_iomap.c | 35 ++++++++++++++++++++++++++++++-----
> 2 files changed, 40 insertions(+), 5 deletions(-)
>
> diff --git a/include/asm-generic/pci_iomap.h b/include/asm-generic/pci_iomap.h
> index ce37349..7389c87 100644
> --- a/include/asm-generic/pci_iomap.h
> +++ b/include/asm-generic/pci_iomap.h
> @@ -15,6 +15,9 @@ 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);
> +extern void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
> + unsigned long offset,
> + unsigned long maxlen);
> /* 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 */
> @@ -30,6 +33,13 @@ static inline void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned lon
> {
> return NULL;
> }
> +
> +static inline void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
> + unsigned long offset,
> + unsigned long maxlen)
> +{
> + return NULL;
> +}
> #endif
>
> #endif /* __ASM_GENERIC_IO_H */
> diff --git a/lib/pci_iomap.c b/lib/pci_iomap.c
> index 0d83ea8..bcce5f1 100644
> --- a/lib/pci_iomap.c
> +++ b/lib/pci_iomap.c
> @@ -10,10 +10,11 @@
>
> #ifdef CONFIG_PCI
> /**
> - * pci_iomap - create a virtual mapping cookie for a PCI BAR
> + * pci_iomap_range - create a virtual mapping cookie for a PCI BAR
> * @dev: PCI device that owns the BAR
> * @bar: BAR number
> - * @maxlen: length of the memory to map
> + * @offset: map memory at the given offset in BAR
> + * @maxlen: max length of the memory to map
> *
> * Using this function you will get a __iomem address to your device BAR.
> * You can access it using ioread*() and iowrite*(). These functions hide
> @@ -21,16 +22,21 @@
> * you expect from them in the correct way.
> *
> * @maxlen specifies the maximum length to map. If you want to get access to
> - * the complete BAR without checking for its length first, pass %0 here.
> + * the complete BAR from offset to the end, pass %0 here.
> * */
> -void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
> +void __iomem *pci_iomap_range(struct pci_dev *dev,
> + int bar,
> + unsigned long offset,
> + unsigned long maxlen)
> {
> resource_size_t start = pci_resource_start(dev, bar);
> resource_size_t len = pci_resource_len(dev, bar);
> unsigned long flags = pci_resource_flags(dev, bar);
>
> - if (!len || !start)
> + if (len <= offset || !start)
> return NULL;
> + len -= offset;
> + start += offset;
> if (maxlen && len > maxlen)
> len = maxlen;
> if (flags & IORESOURCE_IO)
> @@ -43,6 +49,25 @@ void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
> /* What? */
> return NULL;
> }
> +EXPORT_SYMBOL(pci_iomap_range);
>
> +/**
> + * pci_iomap - create a virtual mapping cookie for a PCI BAR
> + * @dev: PCI device that owns the BAR
> + * @bar: BAR number
> + * @maxlen: length of the memory to map
> + *
> + * Using this function you will get a __iomem address to your device BAR.
> + * You can access it using ioread*() and iowrite*(). These functions hide
> + * the details if this is a MMIO or PIO address space and will just do what
> + * you expect from them in the correct way.
> + *
> + * @maxlen specifies the maximum length to map. If you want to get access to
> + * the complete BAR without checking for its length first, pass %0 here.
> + * */
> +void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
> +{
> + return pci_iomap_range(dev, bar, 0, maxlen);
> +}
> EXPORT_SYMBOL(pci_iomap);
> #endif /* CONFIG_PCI */
> --
> MST
>
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