On Sun, Mar 07, 2010 at 01:11:45PM +0100, Albert Herranz wrote: > The current SWIOTLB code does not support NOT_COHERENT_CACHE platforms. > This patch adds support for NOT_COHERENT_CACHE platforms to SWIOTLB by > adding two platform specific functions swiotlb_dma_sync_page() and > swiotlb_dma_sync() which can be used to explicitly manage cache coherency. Hey Albert, I've been doing some posting in this area to split the physical / bus address translation so that multiple platforms can utilize it. I was wondering if it makes sense to utilize some of those concepts (ie, extend it for DMA coherency) for your code: https://lists.linux-foundation.org/pipermail/iommu/2010-February/002066.html And here is the git tree that goes on top of those patches: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb-2.6.git xen-swiotlb-0.5 > > On PowerPC these functions are mapped to their corresponding > __dma_sync_page() and __dma_sync() functions. > On other architectures using SWIOTLB these functions are optimized out. > > This will be used later to support SWIOTLB on the Nintendo Wii video game > console. > > Signed-off-by: Albert Herranz <albert_herranz@xxxxxxxx> > CC: linuxppc-dev@xxxxxxxxxxxxxxxx > CC: linux-kernel@xxxxxxxxxxxxxxx > CC: x86@xxxxxxxxxx > CC: linux-ia64@xxxxxxxxxxxxxxx > --- > arch/ia64/include/asm/swiotlb.h | 10 ++++++++++ > arch/powerpc/include/asm/swiotlb.h | 3 +++ > arch/x86/include/asm/swiotlb.h | 10 ++++++++++ > lib/swiotlb.c | 30 ++++++++++++++++++++++++------ > 4 files changed, 47 insertions(+), 6 deletions(-) > > diff --git a/arch/ia64/include/asm/swiotlb.h b/arch/ia64/include/asm/swiotlb.h > index f0acde6..6722090 100644 > --- a/arch/ia64/include/asm/swiotlb.h > +++ b/arch/ia64/include/asm/swiotlb.h > @@ -14,4 +14,14 @@ static inline void pci_swiotlb_init(void) > } > #endif > > +static inline void swiotlb_dma_sync_page(struct page *page, > + unsigned long offset, > + size_t size, int direction) > +{ > +} > + > +static inline void swiotlb_dma_sync(void *vaddr, size_t size, int direction) > +{ > +} > + > #endif /* ASM_IA64__SWIOTLB_H */ > diff --git a/arch/powerpc/include/asm/swiotlb.h b/arch/powerpc/include/asm/swiotlb.h > index 8979d4c..603b343 100644 > --- a/arch/powerpc/include/asm/swiotlb.h > +++ b/arch/powerpc/include/asm/swiotlb.h > @@ -22,4 +22,7 @@ int __init swiotlb_setup_bus_notifier(void); > > extern void pci_dma_dev_setup_swiotlb(struct pci_dev *pdev); > > +#define swiotlb_dma_sync_page __dma_sync_page > +#define swiotlb_dma_sync __dma_sync > + > #endif /* __ASM_SWIOTLB_H */ > diff --git a/arch/x86/include/asm/swiotlb.h b/arch/x86/include/asm/swiotlb.h > index 8085277..e5f6d9c 100644 > --- a/arch/x86/include/asm/swiotlb.h > +++ b/arch/x86/include/asm/swiotlb.h > @@ -20,4 +20,14 @@ static inline void pci_swiotlb_init(void) > > static inline void dma_mark_clean(void *addr, size_t size) {} > > +static inline void swiotlb_dma_sync_page(struct page *page, > + unsigned long offset, > + size_t size, int direction) > +{ > +} > + > +static inline void swiotlb_dma_sync(void *vaddr, size_t size, int direction) > +{ > +} > + > #endif /* _ASM_X86_SWIOTLB_H */ > diff --git a/lib/swiotlb.c b/lib/swiotlb.c > index 94db5df..8f2dad9 100644 > --- a/lib/swiotlb.c > +++ b/lib/swiotlb.c > @@ -346,10 +346,13 @@ static void swiotlb_bounce(phys_addr_t phys, char *dma_addr, size_t size, > local_irq_save(flags); > buffer = kmap_atomic(pfn_to_page(pfn), > KM_BOUNCE_READ); > - if (dir == DMA_TO_DEVICE) > + if (dir == DMA_TO_DEVICE) { > memcpy(dma_addr, buffer + offset, sz); > - else > + swiotlb_dma_sync(dma_addr, sz, dir); > + } else { > + swiotlb_dma_sync(dma_addr, sz, dir); > memcpy(buffer + offset, dma_addr, sz); > + } > kunmap_atomic(buffer, KM_BOUNCE_READ); > local_irq_restore(flags); > > @@ -359,10 +362,14 @@ static void swiotlb_bounce(phys_addr_t phys, char *dma_addr, size_t size, > offset = 0; > } > } else { > - if (dir == DMA_TO_DEVICE) > + if (dir == DMA_TO_DEVICE) { > memcpy(dma_addr, phys_to_virt(phys), size); > - else > + swiotlb_dma_sync(dma_addr, size, dir); > + > + } else { > + swiotlb_dma_sync(dma_addr, size, dir); > memcpy(phys_to_virt(phys), dma_addr, size); > + } > } > } > > @@ -542,6 +549,8 @@ sync_single(struct device *hwdev, char *dma_addr, size_t size, > } > } > > +#ifndef CONFIG_NOT_COHERENT_CACHE > + > void * > swiotlb_alloc_coherent(struct device *hwdev, size_t size, > dma_addr_t *dma_handle, gfp_t flags) > @@ -606,6 +615,8 @@ swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, > } > EXPORT_SYMBOL(swiotlb_free_coherent); > > +#endif /* !CONFIG_NOT_COHERENT_CACHE */ > + > static void > swiotlb_full(struct device *dev, size_t size, int dir, int do_panic) > { > @@ -652,8 +663,10 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, > * we can safely return the device addr and not worry about bounce > * buffering it. > */ > - if (dma_capable(dev, dev_addr, size) && !swiotlb_force) > + if (dma_capable(dev, dev_addr, size) && !swiotlb_force) { > + swiotlb_dma_sync_page(page, offset, size, dir); > return dev_addr; > + } > > /* > * Oh well, have to allocate and map a bounce buffer. > @@ -739,6 +752,8 @@ swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr, > return; > } > > + swiotlb_dma_sync(phys_to_virt(paddr), size, dir); > + > if (dir != DMA_FROM_DEVICE) > return; > > @@ -835,8 +850,11 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems, > return 0; > } > sg->dma_address = swiotlb_virt_to_bus(hwdev, map); > - } else > + } else { > + swiotlb_dma_sync_page(sg_page(sg), sg->offset, > + sg->length, dir); > sg->dma_address = dev_addr; > + } > sg->dma_length = sg->length; > } > return nelems; > -- > 1.6.3.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
