search for: merge_boundary

...ke cache invalidation hell - you'll need to use invalidate_kernel_vmap_range and flush_kernel_vmap_range to properly handle virtually indexed caches. Or with remapping you mean using the iommu do de-scatter/gather? You can implement that trivially implement it yourself for the iommu case: { merge_boundary = dma_get_merge_boundary(dev); if (!merge_boundary || merge_boundary > chunk_size - 1) { /* can't coalesce */ return -EINVAL; } nents = DIV_ROUND_UP(total_size, chunk_size); sg = sgl_alloc(); for_each_sgl() { sg->page = __alloc_pages(get_order(chunk_size)) sg->len = chu...

...nse, the whole idea of videobuf2-dma-contig is to rely on the DMA API to always provide device-contiguous memory, as required by the hardware which only has a single pointer and size. > > You can implement that trivially implement it yourself for the iommu > case: > > { > merge_boundary = dma_get_merge_boundary(dev); > if (!merge_boundary || merge_boundary > chunk_size - 1) { > /* can't coalesce */ > return -EINVAL; > } > > > nents = DIV_ROUND_UP(total_size, chunk_size); > sg = sgl_alloc...

On Wed, Aug 19, 2020 at 1:51 PM Robin Murphy <robin.murphy at arm.com> wrote: > > Hi Tomasz, > > On 2020-08-19 12:16, Tomasz Figa wrote: > > Hi Christoph, > > > > On Wed, Aug 19, 2020 at 8:56 AM Christoph Hellwig <hch at lst.de> wrote: > >> > >> The V4L2-FLAG-MEMORY-NON-CONSISTENT flag is entirely unused, > > > > Could you