[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v1] swiotlb-xen: implement xen_swiotlb_dma_mmap callback
Hi, Stefano. Can You please confirm that this implementation of the xen_swiotlb_dma_mmap is correct? Oleksandr Dmytryshyn | Product Engineering and Development GlobalLogic M +38.067.382.2525 www.globallogic.com http://www.globallogic.com/email_disclaimer.txt On Tue, Apr 8, 2014 at 3:08 PM, Oleksandr Dmytryshyn <oleksandr.dmytryshyn@xxxxxxxxxxxxxxx> wrote: > From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> > > This function creates userspace mapping for the DMA-coherent memory. > > Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> > Signed-off-by: Oleksandr Dmytryshyn <oleksandr.dmytryshyn@xxxxxxxxxxxxxxx> > --- > arch/arm/xen/mm.c | 1 + > drivers/xen/swiotlb-xen.c | 36 ++++++++++++++++++++++++++++++++++++ > include/xen/swiotlb-xen.h | 5 +++++ > 3 files changed, 42 insertions(+) > > diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c > index b0e77de..91408b1 100644 > --- a/arch/arm/xen/mm.c > +++ b/arch/arm/xen/mm.c > @@ -48,6 +48,7 @@ static struct dma_map_ops xen_swiotlb_dma_ops = { > .sync_sg_for_device = xen_swiotlb_sync_sg_for_device, > .map_sg = xen_swiotlb_map_sg_attrs, > .unmap_sg = xen_swiotlb_unmap_sg_attrs, > + .mmap = xen_swiotlb_dma_mmap, > .map_page = xen_swiotlb_map_page, > .unmap_page = xen_swiotlb_unmap_page, > .dma_supported = xen_swiotlb_dma_supported, > diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c > index 5403855..acf0c06 100644 > --- a/drivers/xen/swiotlb-xen.c > +++ b/drivers/xen/swiotlb-xen.c > @@ -407,6 +407,42 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, > struct page *page, > EXPORT_SYMBOL_GPL(xen_swiotlb_map_page); > > /* > + * Create userspace mapping for the DMA-coherent memory. > + */ > +int xen_swiotlb_dma_mmap(struct device *dev, struct vm_area_struct *vma, > + void *cpu_addr, dma_addr_t dma_addr, size_t size, > + struct dma_attrs *attrs) > +{ > + int ret = -ENXIO; > + unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >> > PAGE_SHIFT; > + unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; > + unsigned long pfn = PFN_DOWN(xen_bus_to_phys(dma_addr)); > + unsigned long off = vma->vm_pgoff; > + pgprot_t prot = vma->vm_page_prot; > + > + prot = dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs) ? > + pgprot_writecombine(prot) : > + pgprot_dmacoherent(prot); > + > + vma->vm_page_prot = prot; > + > + if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) > + return ret; > + > + if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) { > + ret = remap_pfn_range(vma, vma->vm_start, > + pfn + off, > + vma->vm_end - vma->vm_start, > + vma->vm_page_prot); > + } > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(xen_swiotlb_dma_mmap); > + > +/* > * Unmap a single streaming mode DMA translation. The dma_addr and size must > * match what was provided for in a previous xen_swiotlb_map_page call. All > * other usages are undefined. > diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h > index 7b64465..930fa94 100644 > --- a/include/xen/swiotlb-xen.h > +++ b/include/xen/swiotlb-xen.h > @@ -15,6 +15,11 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t > size, > void *vaddr, dma_addr_t dma_handle, > struct dma_attrs *attrs); > > +extern int > +xen_swiotlb_dma_mmap(struct device *dev, struct vm_area_struct *vma, > + void *cpu_addr, dma_addr_t dma_addr, size_t size, > + struct dma_attrs *attrs); > + > extern dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, > unsigned long offset, size_t size, > enum dma_data_direction dir, > -- > 1.8.2.rc2 > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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