> -----Original Message----- > From: Konrad Rzeszutek Wilk [mailto:konrad.wilk@xxxxxxxxxx] > Sent: Tuesday, September 15, 2015 2:40 PM > To: William Davis > Cc: Bjorn Helgaas; Alex Williamson; Joerg Roedel; iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux- > pci@xxxxxxxxxxxxxxx; Mark Hounschell; David S. Miller; Jonathan Corbet; Terence Ripperda; John > Hubbard; Jerome Glisse > Subject: Re: [PATCH 11/22] swiotlb: Add map_peer_resource stub > > On Tue, Sep 15, 2015 at 12:10:56PM -0500, Will Davis wrote: > > Add swiotlb stub of the 'map_peer_resource' DMA operation. > > > > Signed-off-by: Will Davis <wdavis@xxxxxxxxxx> > > --- > > include/linux/swiotlb.h | 8 ++++++++ > > lib/swiotlb.c | 17 +++++++++++++++++ > > 2 files changed, 25 insertions(+) > > > > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > > index e7a018e..872463a 100644 > > --- a/include/linux/swiotlb.h > > +++ b/include/linux/swiotlb.h > > @@ -87,6 +87,14 @@ swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, > > int nelems, enum dma_data_direction dir, > > struct dma_attrs *attrs); > > > > +#ifdef CONFIG_HAS_DMA_P2P > > +extern dma_peer_addr_t > > +swiotlb_map_peer_resource(struct device *hwdev, struct device *hwpeer, > > + struct resource *res, unsigned long offset, > > + size_t size, enum dma_data_direction dir, > > + struct dma_attrs *attrs); > > +#endif > > + > > extern void > > swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr, > > size_t size, enum dma_data_direction dir); > > diff --git a/lib/swiotlb.c b/lib/swiotlb.c > > index 76f29ec..61522a7 100644 > > --- a/lib/swiotlb.c > > +++ b/lib/swiotlb.c > > @@ -945,6 +945,23 @@ swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems, > > } > > EXPORT_SYMBOL(swiotlb_unmap_sg); > > > > +#ifdef CONFIG_HAS_DMA_P2P > > +/* > > + * Maps a single region from a peer device's resource for DMA streaming. This > > + * is currently unimplemented because there's no bounce buffer abstraction for > > + * peer mappings. > > + */ > > +dma_peer_addr_t > > +swiotlb_map_peer_resource(struct device *hwdev, struct device *hwpeer, > > + struct resource *res, unsigned long offset, > > + size_t size, enum dma_data_direction dir, > > + struct dma_attrs *attrs) > > +{ > > + return phys_to_dma(hwdev, io_tlb_overflow_buffer); > > That seems to be implemented :-) > > Did you mean to return DMA_ERROR_CODE instead? I didn't see DMA_ERROR_CODE used in lib/swiotlb.c, and swiotlb_dma_mapping_error is implemented as: return (dma_addr == phys_to_dma(hwdev, io_tlb_overflow_buffer)); So I figured that phys_to_dma(hwdev, io_tlb_overflow_buffer) was intended to be used as DMA_ERROR_CODE instead. Thanks, Will > > +} > > +EXPORT_SYMBOL(swiotlb_map_peer_resource); > > +#endif > > + > > /* > > * Make physical memory consistent for a set of streaming mode DMA translations > > * after a transfer. > > -- > > 2.5.1 > > -- nvpublic -- 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
