Linaro-mm-sig August 2020

linaro-mm-sig@lists.linaro.org

27 participants
18 discussions

[PATCH] dma-resv: lockdep-prime address_space->i_mmap_rwsem for dma-resv

by Daniel Vetter

GPU drivers need this in their shrinkers, to be able to throw out mmap'ed buffers. Note that we also need dma_resv_lock in shrinkers, but that loop is resolved by trylocking in shrinkers. So full hierarchy is now (ignore some of the other branches we already have primed): mmap_read_lock -> dma_resv -> shrinkers -> i_mmap_lock_write I hope that's not inconsistent with anything mm or fs does, adding relevant people. Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: Dave Chinner <david(a)fromorbit.com> Cc: Qian Cai <cai(a)lca.pw> Cc: linux-xfs(a)vger.kernel.org Cc: linux-fsdevel(a)vger.kernel.org Cc: Thomas Hellström (Intel) <thomas_os(a)shipmail.org> Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Jason Gunthorpe <jgg(a)mellanox.com> Cc: linux-mm(a)kvack.org Cc: linux-rdma(a)vger.kernel.org Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> --- drivers/dma-buf/dma-resv.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 0e6675ec1d11..9678162a4ac5 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -104,12 +104,14 @@ static int __init dma_resv_lockdep(void) struct mm_struct *mm = mm_alloc(); struct ww_acquire_ctx ctx; struct dma_resv obj; + struct address_space mapping; int ret; if (!mm) return -ENOMEM; dma_resv_init(&obj); + address_space_init_once(&mapping); mmap_read_lock(mm); ww_acquire_init(&ctx, &reservation_ww_class); @@ -117,6 +119,9 @@ static int __init dma_resv_lockdep(void) if (ret == -EDEADLK) dma_resv_lock_slow(&obj, &ctx); fs_reclaim_acquire(GFP_KERNEL); + /* for unmap_mapping_range on trylocked buffer objects in shrinkers */ + i_mmap_lock_write(&mapping); + i_mmap_unlock_write(&mapping); #ifdef CONFIG_MMU_NOTIFIER lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); __dma_fence_might_wait(); -- 2.27.0

3 years, 7 months

Re: [Linaro-mm-sig] [PATCH 08/29] dma-buf: Avoid comma separated statements

by Christian König

Am 25.08.20 um 06:56 schrieb Joe Perches: > Use semicolons and braces. > > Signed-off-by: Joe Perches <joe(a)perches.com> Acked-by: Christian König <christian.koenig(a)amd.com> > --- > drivers/dma-buf/st-dma-fence.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/dma-buf/st-dma-fence.c b/drivers/dma-buf/st-dma-fence.c > index e593064341c8..c8a12d7ad71a 100644 > --- a/drivers/dma-buf/st-dma-fence.c > +++ b/drivers/dma-buf/st-dma-fence.c > @@ -471,8 +471,11 @@ static int thread_signal_callback(void *arg) > dma_fence_signal(f1); > > smp_store_mb(cb.seen, false); > - if (!f2 || dma_fence_add_callback(f2, &cb.cb, simple_callback)) > - miss++, cb.seen = true; > + if (!f2 || > + dma_fence_add_callback(f2, &cb.cb, simple_callback)) { > + miss++; > + cb.seen = true; > + } > > if (!t->before) > dma_fence_signal(f1);

3 years, 7 months

[PATCH v9 00/32] DRM: fix struct sg_table nents vs. orig_nents misuse

by Marek Szyprowski

Dear All, During the Exynos DRM GEM rework and fixing the issues in the. drm_prime_sg_to_page_addr_arrays() function [1] I've noticed that most drivers in DRM framework incorrectly use nents and orig_nents entries of the struct sg_table. In case of the most DMA-mapping implementations exchanging those two entries or using nents for all loops on the scatterlist is harmless, because they both have the same value. There exists however a DMA-mapping implementations, for which such incorrect usage breaks things. The nents returned by dma_map_sg() might be lower than the nents passed as its parameter and this is perfectly fine. DMA framework or IOMMU is allowed to join consecutive chunks while mapping if such operation is supported by the underlying HW (bus, bridge, IOMMU, etc). Example of the case where dma_map_sg() might return 1 'DMA' chunk for the 4 'physical' pages is described here [2] The DMA-mapping framework documentation [3] states that dma_map_sg() returns the numer of the created entries in the DMA address space. However the subsequent calls to dma_sync_sg_for_{device,cpu} and dma_unmap_sg must be called with the original number of entries passed to dma_map_sg. The common pattern in DRM drivers were to assign the dma_map_sg() return value to sg_table->nents and use that value for the subsequent calls to dma_sync_sg_* or dma_unmap_sg functions. Also the code iterated over nents times to access the pages stored in the processed scatterlist, while it should use orig_nents as the numer of the page entries. I've tried to identify all such incorrect usage of sg_table->nents and this is a result of my research. It looks that the incorrect pattern has been copied over the many drivers mainly in the DRM subsystem. Too bad in most cases it even worked correctly if the system used a simple, linear DMA-mapping implementation, for which swapping nents and orig_nents doesn't make any difference. To avoid similar issues in the future, I've introduced a common wrappers for DMA-mapping calls, which operate directly on the sg_table objects. I've also added wrappers for iterating over the scatterlists stored in the sg_table objects and applied them where possible. This, together with some common DRM prime helpers, allowed me to almost get rid of all nents/orig_nents usage in the drivers. I hope that such change makes the code robust, easier to follow and copy/paste safe. The biggest TODO is DRM/i915 driver and I don't feel brave enough to fix it fully. The driver creatively uses sg_table->orig_nents to store the size of the allocate scatterlist and ignores the number of the entries returned by dma_map_sg function. In this patchset I only fixed the sg_table objects exported by dmabuf related functions. I hope that I didn't break anything there. Patches are based on top of Linux next-20200825. The required changes to DMA-mapping framework has been already merged to v5.8-rc1. I would like ask for merging of the 1-27 patches via DRM misc tree. Best regards, Marek Szyprowski References: [1] https://lkml.org/lkml/2020/3/27/555 [2] https://lkml.org/lkml/2020/3/29/65 [3] Documentation/DMA-API-HOWTO.txt [4] https://lore.kernel.org/linux-iommu/20200512121931.GD20393@lst.de/T/#ma18c9… Changelog: v9: - rebased onto Linux next-20200825, which is based on v5.9-rc2; fixed conflicts - dropped merged patches v8: - rapidio: fixed issues pointed by kbuilt test robot (use of uninitialized variable - vb2: rebased after recent changes in the code v7: https://lore.kernel.org/linux-iommu/20200619103636.11974-1-m.szyprowski@sam… - changed DMA page interators to standard DMA SG iterators in drm/prime and videobuf2-dma-contig as suggested by Robin Murphy - fixed build issues v6: https://lore.kernel.org/linux-iommu/20200618153956.29558-1-m.szyprowski@sam… - rebased onto Linux next-20200618, which is based on v5.8-rc1; fixed conflicts v5: https://lore.kernel.org/linux-iommu/20200513132114.6046-1-m.szyprowski@sams… - fixed some minor style issues and typos - fixed lack of the attrs argument in ion, dmabuf, rapidio, fastrpc and vfio patches v4: https://lore.kernel.org/linux-iommu/20200512121931.GD20393@lst.de/T/ - added for_each_sgtable_* wrappers and applied where possible - added drm_prime_get_contiguous_size() and applied where possible - applied drm_prime_sg_to_page_addr_arrays() where possible to remove page extraction from sg_table objects - added documentation for the introduced wrappers - improved patches description a bit v3: https://lore.kernel.org/dri-devel/20200505083926.28503-1-m.szyprowski@samsu… - introduce dma_*_sgtable_* wrappers and use them in all patches v2: https://lore.kernel.org/linux-iommu/c01c9766-9778-fd1f-f36e-2dc7bd376ba4@ar… - dropped most of the changes to drm/i915 - added fixes for rcar-du, xen, media and ion - fixed a few issues pointed by kbuild test robot - added wide cc: list for each patch v1: https://lore.kernel.org/linux-iommu/c01c9766-9778-fd1f-f36e-2dc7bd376ba4@ar… - initial version Patch summary: Marek Szyprowski (32): drm: prime: add common helper to check scatterlist contiguity drm: prime: use sgtable iterators in drm_prime_sg_to_page_addr_arrays() drm: core: fix common struct sg_table related issues drm: armada: fix common struct sg_table related issues drm: etnaviv: fix common struct sg_table related issues drm: exynos: use common helper for a scatterlist contiguity check drm: exynos: fix common struct sg_table related issues drm: i915: fix common struct sg_table related issues drm: lima: fix common struct sg_table related issues drm: mediatek: use common helper for a scatterlist contiguity check drm: mediatek: use common helper for extracting pages array drm: msm: fix common struct sg_table related issues drm: omapdrm: use common helper for extracting pages array drm: omapdrm: fix common struct sg_table related issues drm: panfrost: fix common struct sg_table related issues drm: rockchip: use common helper for a scatterlist contiguity check drm: rockchip: fix common struct sg_table related issues drm: tegra: fix common struct sg_table related issues drm: v3d: fix common struct sg_table related issues drm: virtio: fix common struct sg_table related issues drm: vmwgfx: fix common struct sg_table related issues drm: xen: fix common struct sg_table related issues xen: gntdev: fix common struct sg_table related issues drm: host1x: fix common struct sg_table related issues drm: rcar-du: fix common struct sg_table related issues dmabuf: fix common struct sg_table related issues staging: tegra-vde: fix common struct sg_table related issues misc: fastrpc: fix common struct sg_table related issues rapidio: fix common struct sg_table related issues samples: vfio-mdev/mbochs: fix common struct sg_table related issues media: pci: fix common ALSA DMA-mapping related codes videobuf2: use sgtable-based scatterlist wrappers drivers/dma-buf/heaps/heap-helpers.c | 13 ++- drivers/dma-buf/udmabuf.c | 7 +- drivers/gpu/drm/armada/armada_gem.c | 12 +-- drivers/gpu/drm/drm_cache.c | 2 +- drivers/gpu/drm/drm_gem_cma_helper.c | 23 +---- drivers/gpu/drm/drm_gem_shmem_helper.c | 14 ++- drivers/gpu/drm/drm_prime.c | 91 +++++++++++-------- drivers/gpu/drm/etnaviv/etnaviv_gem.c | 12 +-- drivers/gpu/drm/etnaviv/etnaviv_mmu.c | 13 +-- drivers/gpu/drm/exynos/exynos_drm_g2d.c | 10 +- drivers/gpu/drm/exynos/exynos_drm_gem.c | 23 +---- drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 11 +-- .../gpu/drm/i915/gem/selftests/mock_dmabuf.c | 7 +- drivers/gpu/drm/lima/lima_gem.c | 11 ++- drivers/gpu/drm/lima/lima_vm.c | 5 +- drivers/gpu/drm/mediatek/mtk_drm_gem.c | 37 ++------ drivers/gpu/drm/msm/msm_gem.c | 13 +-- drivers/gpu/drm/msm/msm_gpummu.c | 14 ++- drivers/gpu/drm/msm/msm_iommu.c | 2 +- drivers/gpu/drm/omapdrm/omap_gem.c | 20 ++-- drivers/gpu/drm/panfrost/panfrost_gem.c | 4 +- drivers/gpu/drm/panfrost/panfrost_mmu.c | 7 +- drivers/gpu/drm/rcar-du/rcar_du_vsp.c | 3 +- drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 42 +++------ drivers/gpu/drm/tegra/gem.c | 27 ++---- drivers/gpu/drm/tegra/plane.c | 15 +-- drivers/gpu/drm/v3d/v3d_mmu.c | 13 ++- drivers/gpu/drm/virtio/virtgpu_object.c | 36 +++++--- drivers/gpu/drm/virtio/virtgpu_vq.c | 12 +-- drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c | 17 +--- drivers/gpu/drm/xen/xen_drm_front_gem.c | 2 +- drivers/gpu/host1x/job.c | 22 ++--- .../common/videobuf2/videobuf2-dma-contig.c | 34 +++---- .../media/common/videobuf2/videobuf2-dma-sg.c | 32 +++---- .../common/videobuf2/videobuf2-vmalloc.c | 12 +-- drivers/media/pci/cx23885/cx23885-alsa.c | 2 +- drivers/media/pci/cx25821/cx25821-alsa.c | 2 +- drivers/media/pci/cx88/cx88-alsa.c | 2 +- drivers/media/pci/saa7134/saa7134-alsa.c | 2 +- drivers/media/platform/vsp1/vsp1_drm.c | 8 +- drivers/misc/fastrpc.c | 4 +- drivers/rapidio/devices/rio_mport_cdev.c | 11 +-- drivers/staging/media/tegra-vde/iommu.c | 4 +- drivers/xen/gntdev-dmabuf.c | 13 ++- include/drm/drm_prime.h | 2 + samples/vfio-mdev/mbochs.c | 3 +- 46 files changed, 273 insertions(+), 398 deletions(-) -- 2.17.1

3 years, 7 months

Re: [Linaro-mm-sig] [PATCH] staging: ion: remove from the tree

by Greg Kroah-Hartman

On Thu, Aug 27, 2020 at 10:31:41PM +0530, Amit Pundir wrote: > On Thu, 27 Aug 2020 at 21:34, Greg Kroah-Hartman > <gregkh(a)linuxfoundation.org> wrote: > > > > On Thu, Aug 27, 2020 at 09:31:27AM -0400, Laura Abbott wrote: > > > On 8/27/20 8:36 AM, Greg Kroah-Hartman wrote: > > > > The ION android code has long been marked to be removed, now that we > > > > dma-buf support merged into the real part of the kernel. > > > > > > > > It was thought that we could wait to remove the ion kernel at a later > > > > time, but as the out-of-tree Android fork of the ion code has diverged > > > > quite a bit, and any Android device using the ion interface uses that > > > > forked version and not this in-tree version, the in-tree copy of the > > > > code is abandonded and not used by anyone. > > > > > > > > Combine this abandoned codebase with the need to make changes to it in > > > > order to keep the kernel building properly, which then causes merge > > > > issues when merging those changes into the out-of-tree Android code, and > > > > you end up with two different groups of people (the in-kernel-tree > > > > developers, and the Android kernel developers) who are both annoyed at > > > > the current situation. Because of this problem, just drop the in-kernel > > > > copy of the ion code now, as it's not used, and is only causing problems > > > > for everyone involved. > > > > > > > > Cc: "Arve Hjønnevåg" <arve(a)android.com> > > > > Cc: "Christian König" <christian.koenig(a)amd.com> > > > > Cc: Christian Brauner <christian(a)brauner.io> > > > > Cc: Christoph Hellwig <hch(a)infradead.org> > > > > Cc: Hridya Valsaraju <hridya(a)google.com> > > > > Cc: Joel Fernandes <joel(a)joelfernandes.org> > > > > Cc: John Stultz <john.stultz(a)linaro.org> > > > > Cc: Laura Abbott <laura(a)labbott.name> > > > > Cc: Martijn Coenen <maco(a)android.com> > > > > Cc: Shuah Khan <shuah(a)kernel.org> > > > > Cc: Sumit Semwal <sumit.semwal(a)linaro.org> > > > > Cc: Suren Baghdasaryan <surenb(a)google.com> > > > > Cc: Todd Kjos <tkjos(a)android.com> > > > > Cc: devel(a)driverdev.osuosl.org > > > > Cc: dri-devel(a)lists.freedesktop.org > > > > Cc: linaro-mm-sig(a)lists.linaro.org > > > > Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> > > > > > > We discussed this at the Android MC on Monday and the plan was to > > > remove it after the next LTS release. > > > > I know it was discussed, my point is that it is actually causing > > problems now (with developers who want to change the internal kernel api > > hitting issues, and newbies trying to clean up code in ways that isn't > > exactly optimal wasting maintainer cycles), and that anyone who uses > > this code, is not actually using this version of the code. Everyone who > > relies on ion right now, is using the version that is in the Android > > common kernel tree, which has diverged from this in-kernel way quite a > > bit now for the reason that we didn't want to take any of those new > > features in the in-kernel version. > > > > So this is a problem that we have caused by just wanting to wait, no one > > is using this code, combined with it causing problems for the upstream > > developers. > > > > There is nothing "magic" about the last kernel of the year that requires > > this code to sit here until then. At that point in time, all users > > will, again, be using the forked Android kernel version, and if we > > delete this now here, that fork can remain just fine, with the added > > benifit of it reducing developer workloads here in-kernel. > > > > So why wait? > > Hi, > > I don't know what is the right thing to do here. I just want to > highlight that AOSP's audio (codec2) HAL depends on the ION system > heap and it will break AOSP for people who boot mainline on their > devices, even for just testing purpose like we do in Linaro. Right now > we need only 1 (Android specific out-of-tree) patch to boot AOSP with > mainline and Sumit is already trying to upstream that vma naming > patch. Removal of in-kernel ION, will just add more to that delta. As AOSP will continue to rely on ION after December of this year, all you are doing is postponing the inevitable a few more months. Push back on the Android team to fix up the code to not use ION, they know this needs to happen. thanks, greg k-h

3 years, 8 months

Re: [Linaro-mm-sig] [PATCH] staging: ion: remove from the tree

by Greg Kroah-Hartman

On Thu, Aug 27, 2020 at 09:31:27AM -0400, Laura Abbott wrote: > On 8/27/20 8:36 AM, Greg Kroah-Hartman wrote: > > The ION android code has long been marked to be removed, now that we > > dma-buf support merged into the real part of the kernel. > > > > It was thought that we could wait to remove the ion kernel at a later > > time, but as the out-of-tree Android fork of the ion code has diverged > > quite a bit, and any Android device using the ion interface uses that > > forked version and not this in-tree version, the in-tree copy of the > > code is abandonded and not used by anyone. > > > > Combine this abandoned codebase with the need to make changes to it in > > order to keep the kernel building properly, which then causes merge > > issues when merging those changes into the out-of-tree Android code, and > > you end up with two different groups of people (the in-kernel-tree > > developers, and the Android kernel developers) who are both annoyed at > > the current situation. Because of this problem, just drop the in-kernel > > copy of the ion code now, as it's not used, and is only causing problems > > for everyone involved. > > > > Cc: "Arve Hjønnevåg" <arve(a)android.com> > > Cc: "Christian König" <christian.koenig(a)amd.com> > > Cc: Christian Brauner <christian(a)brauner.io> > > Cc: Christoph Hellwig <hch(a)infradead.org> > > Cc: Hridya Valsaraju <hridya(a)google.com> > > Cc: Joel Fernandes <joel(a)joelfernandes.org> > > Cc: John Stultz <john.stultz(a)linaro.org> > > Cc: Laura Abbott <laura(a)labbott.name> > > Cc: Martijn Coenen <maco(a)android.com> > > Cc: Shuah Khan <shuah(a)kernel.org> > > Cc: Sumit Semwal <sumit.semwal(a)linaro.org> > > Cc: Suren Baghdasaryan <surenb(a)google.com> > > Cc: Todd Kjos <tkjos(a)android.com> > > Cc: devel(a)driverdev.osuosl.org > > Cc: dri-devel(a)lists.freedesktop.org > > Cc: linaro-mm-sig(a)lists.linaro.org > > Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> > > We discussed this at the Android MC on Monday and the plan was to > remove it after the next LTS release. I know it was discussed, my point is that it is actually causing problems now (with developers who want to change the internal kernel api hitting issues, and newbies trying to clean up code in ways that isn't exactly optimal wasting maintainer cycles), and that anyone who uses this code, is not actually using this version of the code. Everyone who relies on ion right now, is using the version that is in the Android common kernel tree, which has diverged from this in-kernel way quite a bit now for the reason that we didn't want to take any of those new features in the in-kernel version. So this is a problem that we have caused by just wanting to wait, no one is using this code, combined with it causing problems for the upstream developers. There is nothing "magic" about the last kernel of the year that requires this code to sit here until then. At that point in time, all users will, again, be using the forked Android kernel version, and if we delete this now here, that fork can remain just fine, with the added benifit of it reducing developer workloads here in-kernel. So why wait? thanks, greg k-h

3 years, 8 months

Re: [Linaro-mm-sig] [PATCH] dma-buf: heaps: Introduce dma_heap_add_cma() for non-default CMA heap

by John Stultz

On Fri, Aug 21, 2020 at 2:14 AM Kunihiko Hayashi <hayashi.kunihiko(a)socionext.com> wrote: > > On 2020/08/01 4:38, John Stultz wrote: > > On Fri, Jul 31, 2020 at 2:32 AM Kunihiko Hayashi > > <hayashi.kunihiko(a)socionext.com> wrote: > >> On 2020/07/29 4:17, John Stultz wrote: > >>> Do you have a upstream driver that you plan to make use this new call? > >> > >> Unfortunately I don't have an upstream driver using this call. > >> > >> This call is called from dma-buf heaps "importer" or "customer", > >> and I only made an example (do nothing) importer driver > >> to test the call. > >> > >>> We want to have in-tree users of code added. > >> > >> I think this is a generic way to use non-default CMA heaps, however, > >> we need in-tree "importer" drivers to want to use non-default CMA heaps. > >> I don't find it from now. > >> > > > > Yea, I and again, I do agree this is functionality that will be > > needed. But we'll need to wait for a user (camera driver, etc which > > would utilize the reserved cma region) before we can merge it > > upstream. :( Do let me know if you have an out of tree driver that > > would make use of it, and we can see what can be done to help upstream > > things. > > Sorry for late. > Before I prepare or find a user driver as "importer", > I think something is different in this patch. > > This patch makes it possible to treat non-default CMA connected to > "importer" device with memory-region as dma-buf heaps. > > However, the allocated memory from this dma-buf heaps can be used > for "any" devices, and the "importer" can treat memories from other > dma-buf heaps. > > So, the "importer" and the non-default CMA aren't directly related, > and I think an "exporter" for the non-default CMA should be enabled. > > In paticular, the kernel initializer (as an "exporter") calls > dma_heap_add_cma() for all CMAs defined in Devicetree, and > the device files associated with each CMA appear under "/dev/dma_heap/". > For example: > > /dev/dma_heap/linux,cma@10000000 > /dev/dma_heap/linux,cma@11000000 > /dev/dma_heap/linux,cma@12000000 > ... > > All of these device files can be fairly allocated to any "importer" device. > > Actually I think that the kernel should executes dma_heap_add_cma() > for ALL defined reserved-memory nodes. > > If this idea hasn't been discussed yet and this is reasonable, > I'll prepare RFC patches. So yes! An earlier version of the CMA heap I submitted did add all CMA regions as accessible heaps as you propose here. However, the concern was that in some cases, those regions are device specific reserved memory that the driver is probably expecting to have exclusive access. To allow (sufficiently privileged, or misconfigured) userland to be able to allocate out of that seemed like it might cause trouble, and instead we should have CMA regions explicitly exported. There was some proposal to add a dt property to the reserved memory section (similar to linux,cma-default) and use that to do the exporting, but other discussions seemed to prefer having drivers export it explicitly in a fashion very similar to what your earlier patch does. The only trouble is we just need an upstream driver to add such a call in the series before we can merge it. thanks -john

3 years, 8 months

[PATCH 0/3] Chunk Heap Support on DMA-HEAP

by Hyesoo Yu

These patch series to introduce a new dma heap, chunk heap. That heap is needed for special HW that requires bulk allocation of fixed high order pages. For example, 64MB dma-buf pages are made up to fixed order-4 pages * 1024. The chunk heap uses alloc_pages_bulk to allocate high order page. https://lore.kernel.org/linux-mm/20200814173131.2803002-1-minchan@kernel.org The chunk heap is registered by device tree with alignment and memory node of contiguous memory allocator(CMA). Alignment defines chunk page size. For example, alignment 0x1_0000 means chunk page size is 64KB. The phandle to memory node indicates contiguous memory allocator(CMA). If device node doesn't have cma, the registration of chunk heap fails. The patchset includes the following: - export dma-heap API to register kernel module dma heap. - add chunk heap implementation. - document of device tree to register chunk heap Hyesoo Yu (3): dma-buf: add missing EXPORT_SYMBOL_GPL() for dma heaps dma-buf: heaps: add chunk heap to dmabuf heaps dma-heap: Devicetree binding for chunk heap .../devicetree/bindings/dma-buf/chunk_heap.yaml | 46 +++++ drivers/dma-buf/dma-heap.c | 2 + drivers/dma-buf/heaps/Kconfig | 9 + drivers/dma-buf/heaps/Makefile | 1 + drivers/dma-buf/heaps/chunk_heap.c | 222 +++++++++++++++++++++ drivers/dma-buf/heaps/heap-helpers.c | 2 + 6 files changed, 282 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma-buf/chunk_heap.yaml create mode 100644 drivers/dma-buf/heaps/chunk_heap.c -- 2.7.4

3 years, 8 months

[RESEND PATCH 1/2] dma-buf: Fix kerneldoc of dma_buf_set_name()

by Krzysztof Kozlowski

Fix W=1 compile warnings (invalid kerneldoc): drivers/dma-buf/dma-buf.c:328: warning: Function parameter or member 'dmabuf' not described in 'dma_buf_set_name' Signed-off-by: Krzysztof Kozlowski <krzk(a)kernel.org> --- drivers/dma-buf/dma-buf.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 1699a8e309ef..58564d82a3a2 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -316,9 +316,9 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll) * name of the dma-buf if the same piece of memory is used for multiple * purpose between different devices. * - * @dmabuf [in] dmabuf buffer that will be renamed. - * @buf: [in] A piece of userspace memory that contains the name of - * the dma-buf. + * @dmabuf: [in] dmabuf buffer that will be renamed. + * @buf: [in] A piece of userspace memory that contains the name of + * the dma-buf. * * Returns 0 on success. If the dma-buf buffer is already attached to * devices, return -EBUSY. -- 2.17.1

3 years, 8 months

Re: [Linaro-mm-sig] [PATCH 0/4] *** SUBJECT HERE ***

by Greg Kroah-Hartman

On Tue, Aug 18, 2020 at 12:17:08PM +0300, Tomer Samara wrote: > *** BLURB HERE *** Really? And your subject line could use some work too :(

3 years, 8 months

[PATCH v7 0/3] Support virtio cross-device resources

by David Stevens

This patchset implements the current proposal for virtio cross-device resource sharing [1]. It will be used to import virtio resources into the virtio-video driver currently under discussion [2]. The patch under consideration to add support in the virtio-video driver is [3]. It uses the APIs from v3 of this series, but the changes to update it are relatively minor. This patchset adds a new flavor of dma-bufs that supports querying the underlying virtio object UUID, as well as adding support for exporting resources from virtgpu. [1] https://markmail.org/thread/2ypjt5cfeu3m6lxu [2] https://markmail.org/thread/p5d3k566srtdtute [3] https://markmail.org/thread/j4xlqaaim266qpks v6 -> v7 changes: - Fix most strict checkpatch comments David Stevens (3): virtio: add dma-buf support for exported objects virtio-gpu: add VIRTIO_GPU_F_RESOURCE_UUID feature drm/virtio: Support virtgpu exported resources drivers/gpu/drm/virtio/virtgpu_drv.c | 3 + drivers/gpu/drm/virtio/virtgpu_drv.h | 21 ++++++ drivers/gpu/drm/virtio/virtgpu_kms.c | 4 ++ drivers/gpu/drm/virtio/virtgpu_prime.c | 96 +++++++++++++++++++++++++- drivers/gpu/drm/virtio/virtgpu_vq.c | 55 +++++++++++++++ drivers/virtio/Makefile | 2 +- drivers/virtio/virtio.c | 6 ++ drivers/virtio/virtio_dma_buf.c | 85 +++++++++++++++++++++++ include/linux/virtio.h | 1 + include/linux/virtio_dma_buf.h | 37 ++++++++++ include/uapi/linux/virtio_gpu.h | 19 +++++ 11 files changed, 325 insertions(+), 4 deletions(-) create mode 100644 drivers/virtio/virtio_dma_buf.c create mode 100644 include/linux/virtio_dma_buf.h -- 2.28.0.220.ged08abb693-goog

3 years, 8 months

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Linaro-mm-sig August 2020