Re: [PATCH 3/5] swiotlb: swiotlb_bus_to_virt/phys prototype changes

FUJITA Tomonori
2009-03-25T03:06:57Z

On Tue, 24 Mar 2009 16:28:44 -0500
Becky Bruce <beckyb@kernel.crashing.org> wrote:

> Make these functions take the hwdev as an argument because on some
> platforms it contains a per-device offset that is used to convert
> from bus addresses to/from other types of addresses.
>
> Also, make these weak so architectures can override the default
> behavior (for example, by adding an offset in the hwdev).
>
> Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
> ---
> arch/x86/kernel/pci-swiotlb.c | 2 +-
> include/linux/swiotlb.h | 4 +++-
> lib/swiotlb.c | 31 +++++++++++++++++++------------
> 3 files changed, 23 insertions(+), 14 deletions(-)

> @@ -847,10 +847,14 @@ swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
>
> for_each_sg(sgl, sg, nelems, i) {
> if (sg->dma_address != swiotlb_phys_to_bus(hwdev, sg_phys(sg)))
> - unmap_single(hwdev, swiotlb_bus_to_virt(sg->dma_address),
> - sg->dma_length, dir);
> + unmap_single(
> + hwdev,
> + swiotlb_bus_to_virt(hwdev, sg->dma_address),
> + sg->dma_length, dir);
> else if (dir == DMA_FROM_DEVICE)
> - dma_mark_clean(swiotlb_bus_to_virt(sg->dma_address), sg->dma_length);
> + dma_mark_clean(
> + swiotlb_bus_to_virt(hwdev, sg->dma_address),
> + sg->dma_length);
> }

The coding style looks a bit odd to me. How about something like this?

for_each_sg(sgl, sg, nelems, i) {
void *virt = swiotlb_bus_to_virt(hwdev, sg->dma_address),
if (sg->dma_address != swiotlb_phys_to_bus(hwdev, sg_phys(sg)))
unmap_single(hwdev, virt, sg->dma_length, dir);
else if (dir == DMA_FROM_DEVICE)
dma_mark_clean(virt, sg->dma_length);

> }
> EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);
> @@ -881,10 +885,13 @@ swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
>
> for_each_sg(sgl, sg, nelems, i) {
> if (sg->dma_address != swiotlb_phys_to_bus(hwdev, sg_phys(sg)))
> - sync_single(hwdev, swiotlb_bus_to_virt(sg->dma_address),
> + sync_single(hwdev,
> + swiotlb_bus_to_virt(hwdev, sg->dma_address),
> sg->dma_length, dir, target);
> else if (dir == DMA_FROM_DEVICE)
> - dma_mark_clean(swiotlb_bus_to_virt(sg->dma_address), sg->dma_length);
> + dma_mark_clean(
> + swiotlb_bus_to_virt(hwdev, sg->dma_address),
> + sg->dma_length);
> }

Ditto.

The rest looks fine to me.