2012/7/25 Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx>:
> The patch implements the weak function to return the default I/O
> or memory alignment for P2P bridge. Currently, I/O window has 4KiB
> alignment and memory window is 4MiB aligned by default. On the other
> hand, those platforms (e.g. powernv) that have special requirements
> on the alignment could override the function by themselves.
>
> Signed-off-by: Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/pci/setup-bus.c | 21 +++++++++++++++++++++
> include/linux/pci.h | 2 ++
> 2 files changed, 23 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
> index 8fa2d4b..c0fb9da 100644
> --- a/drivers/pci/setup-bus.c
> +++ b/drivers/pci/setup-bus.c
> @@ -690,6 +690,27 @@ static resource_size_t calculate_memsize(resource_size_t size,
> return size;
> }
>
> +resource_size_t __weak pcibios_window_alignment(struct pci_bus *bus,
> + unsigned long type)
> +{
> + return 1;
> +}
> +
> +static resource_size_t window_alignment(struct pci_bus *bus,
> + unsigned long type)
> +{
> + resource_size_t align = 1, arch_align;
> +
> + if (type & IORESOURCE_MEM)
> + align = 1024*1024; /* 1MiB */
> + else if (type & IORESOURCE_IO)
> + align = 4*1024; /* 4KiB */
> +
If this is a constant, could we use define a macro?
So we don't use to calculate the value every time.
Maybe some compile will be smart enough to optimize this,
still think it is better to give a result.
> + arch_align = pcibios_window_alignment(bus, type);
> +
> + return max(align, arch_align);
> +}
> +
> /**
> * pbus_size_io() - size the io window of a given bus
> *
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 9acea4b..34ff2bb 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -988,6 +988,8 @@ int pci_cfg_space_size_ext(struct pci_dev *dev);
> int pci_cfg_space_size(struct pci_dev *dev);
> unsigned char pci_bus_max_busnr(struct pci_bus *bus);
> void pci_setup_bridge(struct pci_bus *bus);
> +resource_size_t pcibios_window_alignment(struct pci_bus *bus,
> + unsigned long type);
>
> #define PCI_VGA_STATE_CHANGE_BRIDGE (1 << 0)
> #define PCI_VGA_STATE_CHANGE_DECODES (1 << 1)
> --
> 1.7.5.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Richard Yang
Help You, Help Me
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
