On Mon, Aug 20, 2012 at 7:46 AM, Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx> wrote:
> The patch changes function pbus_size_io() and pbus_size_mem() to
> do resource (I/O, memory and prefetchable memory) reassignment
> based on the minimal alignments for the p2p bridge, which was
> retrieved by function window_alignment().
>
> Signed-off-by: Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/pci/setup-bus.c | 16 ++++++++++++----
> 1 files changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
> index 826a4f3..bb2eade 100644
> --- a/drivers/pci/setup-bus.c
> +++ b/drivers/pci/setup-bus.c
> @@ -741,7 +741,7 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
> struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
> unsigned long size = 0, size0 = 0, size1 = 0;
> resource_size_t children_add_size = 0;
> - resource_size_t min_align = 4096, align;
> + resource_size_t io_align, min_align, align;
>
> if (!b_res)
> return;
> @@ -750,8 +750,14 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
> * Per spec, I/O windows are 4K-aligned, but some bridges have an
> * extension to support 1K alignment.
> */
> - if (bus->self->io_window_1k)
> + if (bus->self->io_window_1k) {
> + io_align = 4096;
Why is io_align 4K instead of 1K here?
> min_align = 1024;
> + } else {
> + io_align = window_alignment(bus, IORESOURCE_IO);
This doesn't seem right. Only the non-1k path uses
window_alignment(), so there's no way for the platform to influence
the alignment of bridges that support 1k windows. I think the
io_window_1k checking needs to be moved from pbus_size_io() to
window_alignment().
Maybe you can then make the min_align handling in pbus_size_io() more
similar to that in pbus_size_mem(), e.g.,
min_align = 0;
...
min_align = max(min_align, window_alignment(bus, b_res->flags & mask));
> + min_align = io_align;
> + }
> +
> list_for_each_entry(dev, &bus->devices, bus_list) {
> int i;
>
> @@ -778,8 +784,8 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
> }
> }
>
> - if (min_align > 4096)
> - min_align = 4096;
> + if (min_align > io_align)
> + min_align = io_align;
>
> size0 = calculate_iosize(size, min_size, size1,
> resource_size(b_res), min_align);
> @@ -901,6 +907,8 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
> min_align = align1 >> 1;
> align += aligns[order];
> }
> +
> + min_align = max(min_align, window_alignment(bus, b_res->flags & mask));
> size0 = calculate_memsize(size, min_size, 0, resource_size(b_res), min_align);
> if (children_add_size > add_size)
> add_size = children_add_size;
> --
> 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
--
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
