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

Becky Bruce
2009-03-25T03:55:37Z

On Mar 24, 2009, at 9:58 PM, FUJITA Tomonori wrote:

> 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);

Heh, I was trying to avoid > 80 character lines there, and it ended up
looking a bit gross. I originally had *exactly* what you suggest in
my tree, but changed it, so I'm more than happy to change this back.

>
>
>
>> }
>> 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.

Thanks for the review!

Cheers,
-Becky