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

[Becky Bruce]

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

> On Tue, 24 Mar 2009 16:28:44 -0500
> Becky Bruce <beckyb@xxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxx>
> > ---
> > 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

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