similar to: a saner API for allocating DMA addressable pages

Hi all, this series replaced the DMA_ATTR_NON_CONSISTENT flag to dma_alloc_attrs with a separate new dma_alloc_pages API, which is available on all platforms. In addition to cleaning up the convoluted code path, this ensures that other drivers that have asked for better support for non-coherent DMA to pages with incurring bounce buffering over can finally be properly supported. I'm still a

Hi all, this series replaced the DMA_ATTR_NON_CONSISTENT flag to dma_alloc_attrs with a separate new dma_alloc_pages API, which is available on all platforms. In addition to cleaning up the convoluted code path, this ensures that other drivers that have asked for better support for non-coherent DMA to pages with incurring bounce buffering over can finally be properly supported. As a follow up I

Hi, This is third approach (complete this time) for replacing struct dma_attrs with unsigned long. The main patch (2/45) doing the change is split into many subpatches for easier review (3-43). They should be squashed together when applying. *Important:* Patchset is *only* build tested on allyesconfigs: ARM, ARM64, i386, x86_64 and powerpc. Please provide reviewes and tests for other

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

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 explain what makes you think it's unused? It's a feature of the UAPI generally supported by the videobuf2 framework and relied on by Chromium OS to get any kind of reasonable performance when accessing V4L2 buffers

Switch the 53c700 driver to only use non-coherent descriptor memory if it really has to because dma_alloc_coherent fails. This doesn't matter for any of the platforms it runs on currently, but that will change soon. To help with this two new helpers to transfer ownership to and from the device are added that abstract the syncing of the non-coherent memory. The two current bidirectional cases

Hi, here is the next version of this patch-set. Previous versions can be found here: V1: https://lore.kernel.org/lkml/20190110134433.15672-1-joro at 8bytes.org/ V2: https://lore.kernel.org/lkml/20190115132257.6426-1-joro at 8bytes.org/ V3: https://lore.kernel.org/lkml/20190123163049.24863-1-joro at 8bytes.org/ V4: https://lore.kernel.org/lkml/20190129084342.26030-1-joro at 8bytes.org/

Hi all, Here''s a work in progress series whcih does a partial revert of the previous swiotlb changes, and does a partial replacement with Becky Bruce''s series. The most important difference is Becky''s use of phys_addr_t rather than page+offset to represent arbitrary pages. This turns out to be simpler. I didn''t replicate the map_single_page changes, since

Convert the AMD iommu driver to the dma-iommu api. Remove the iova handling and reserve region code from the AMD iommu driver. Change-log: V6: -add more details to the description of patch 001-iommu-amd-Remove-unnecessary-locking-from-AMD-iommu-.patch -rename handle_deferred_device to iommu_dma_deferred_attach -fix double tabs in 0003-iommu-dma-iommu-Handle-deferred-devices.patch V5: -Rebase on

Convert the AMD iommu driver to the dma-iommu api. Remove the iova handling and reserve region code from the AMD iommu driver. Change-log: V4: -Rebase on top of linux-next -Split the removing of the unnecessary locking in the amd iommu driver into a seperate patch -refactor the "iommu/dma-iommu: Handle deferred devices" patch and address comments v3: -rename dma_limit to dma_mask -exit

Convert the AMD iommu driver to the dma-iommu api. Remove the iova handling and reserve region code from the AMD iommu driver. Change-log: V4: -Rebase on top of linux-next -Split the removing of the unnecessary locking in the amd iommu driver into a seperate patch -refactor the "iommu/dma-iommu: Handle deferred devices" patch and address comments v3: -rename dma_limit to dma_mask -exit

This patchset converts the intel iommu driver to the dma-iommu api. While converting the driver I exposed a bug in the intel i915 driver which causes a huge amount of artifacts on the screen of my laptop. You can see a picture of it here: https://github.com/pippy360/kernelPatches/blob/master/IMG_20191219_225922.jpg This issue is most likely in the i915 driver and is most likely caused by the

This patchset converts the intel iommu driver to the dma-iommu api. While converting the driver I exposed a bug in the intel i915 driver which causes a huge amount of artifacts on the screen of my laptop. You can see a picture of it here: https://github.com/pippy360/kernelPatches/blob/master/IMG_20191219_225922.jpg This issue is most likely in the i915 driver and is most likely caused by the

Hi all, this patch series enables xen-swiotlb on arm and arm64. It has been heavily reworked compared to the previous versions in order to achieve better performances and to address review comments. We are not using dma_mark_clean to ensure coherency anymore. We call the platform implementation of map_page and unmap_page. We assume that dom0 has been mapped 1:1 (physical address == machine

Hi all, this patch series introduces support for running Linux on top of Xen inside a virtual machine with virtio devices (nested virt scenario). The problem is that Linux virtio drivers use virt_to_phys to get the guest pseudo-physical addresses to pass to the backend, which doesn't work as expected on Xen. Switching the virtio drivers to the dma APIs (dma_alloc_coherent,

Hi all, this patch series introduces support for running Linux on top of Xen inside a virtual machine with virtio devices (nested virt scenario). The problem is that Linux virtio drivers use virt_to_phys to get the guest pseudo-physical addresses to pass to the backend, which doesn't work as expected on Xen. Switching the virtio drivers to the dma APIs (dma_alloc_coherent,

It seems the problems running mthca in a Xen domU have uncovered a bug in mthca: mthca uses dma_sync_single in mthca_arbel_write_mtt_seg() and mthca_arbel_map_phys_fmr() to sync the MTTs that get written. However, Documentation/DMA-API.txt says: void dma_sync_single(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction direction) synchronise a single

On Wed, Aug 19, 2020 at 03:07:04PM +0100, Robin Murphy wrote: >> FWIW, I asked back in time what the plan is for non-coherent >> allocations and it seemed like DMA_ATTR_NON_CONSISTENT and >> dma_sync_*() was supposed to be the right thing to go with. [2] The >> same thread also explains why dma_alloc_pages() isn't suitable for the >> users of dma_alloc_attrs() and

On Fri, May 19, 2023 at 01:49:46PM +0100, Andrew Cooper wrote: > > The alternative would be to finally merge swiotlb-xen into swiotlb, in > > which case we might be able to do this later. Let me see what I can > > do there. > > If that is an option, it would be great to reduce the special-cashing. I think it's doable, and I've been wanting it for a while. I just

Add a new API to allocate and free pages that are guaranteed to be addressable by a device, but otherwise behave like pages allocated by alloc_pages. The intended APIs to sync them for use with the device and cpu are dma_sync_single_for_{device,cpu} that are also used for streaming mappings. Switch all drivers over to this new API, but keep the usage of the crufty dma_cache_sync API for now,