Linaro-mm-sig

linaro-mm-sig@lists.linaro.org

12 participants
7072 discussions

[PATCH v13 0/5] Rust bindings for gem shmem

by Lyude Paul

Most of this patch series has already been pushed upstream, this is just the second half of the patch series that has not been pushed yet + some additional changes which were required to implement changes requested by the mailing list. This patch series is originally from Asahi, previously posted by Daniel Almeida. The previous version of the patch series can be found here: https://patchwork.freedesktop.org/series/164580/ Branch with patches applied available here sure this builds: https://gitlab.freedesktop.org/lyudess/linux/-/commits/rust/gem-shmem This patch series applies on top of drm-rust-next Lyude Paul (5): rust: drm: gem: s/device::Device/Device/ for shmem.rs drm/gem/shmem: Introduce __drm_gem_shmem_free_sgt_locked() rust: drm: gem/shmem: Add DmaResvGuard helper rust: drm: gem: Introduce shmem::SGTable rust: drm: gem: Add vmap functions to shmem bindings drivers/gpu/drm/drm_gem_shmem_helper.c | 32 +- include/drm/drm_gem_shmem_helper.h | 1 + rust/kernel/drm/gem/shmem.rs | 602 ++++++++++++++++++++++++- 3 files changed, 614 insertions(+), 21 deletions(-) base-commit: d9a6809478f9815b6455a327aa001737ac7b2c09 -- 2.54.0

2 months

[PATCH RFC 0/3] media: videobuf2: opt-in dma_resv producer fences for V4L2 dmabuf exports

by Markus Fritsche

Hi, This series proposes a small opt-in API in videobuf2-core that lets V4L2 drivers populate a dma_resv exclusive write fence on the dmabufs they export to userspace, signalled when the buffer transitions to VB2_BUF_STATE_DONE. Two example drivers (hantro, rockchip-rga) opt in to demonstrate the call shape; the change is no-op for every other driver. Why --- Modern Wayland compositors and any other userspace consumers that import V4L2-produced dmabufs and want to do implicit synchronization the spec-clean way (poll(POLLIN) on the dmabuf fd, or DMA_BUF_IOCTL_EXPORT_SYNC_FILE for a sync_file) currently get either: 1. A stub fence from dma_buf_export_sync_file(), because the dmabuf's dma_resv has no fences populated. The kernel substitutes dma_fence_get_stub() which is permanently signalled. The compositor "successfully" waits on a fence that represents nothing real about the producer's state. 2. A poll(POLLIN) on the dmabuf fd that returns immediately for the same reason — dma_buf_poll_add_cb finds zero fences in the resv, triggers the wake callback inline, and reports POLLIN ready before the producer has actually said anything. Today this works as a happy accident on most paths because clients attach buffers after VIDIOC_DQBUF, which the userspace V4L2 contract guarantees only returns a buffer after the producer is done. So the implicit "the kernel's stub fence is fine because the buffer is already complete by the time anyone polls it" assumption has held. But: - It's a contract gap. The kernel claims to expose implicit sync; it does not, for V4L2 producers. - It paid latency for nothing. Every Wayland frame from a V4L2 producer pays a DMA_BUF_IOCTL_EXPORT_SYNC_FILE round-trip for a fence that's stub-signalled. On Mali-class hardware (RK3566 Wayland chrome video playback), this contributed to compositor stalls. Removing the wait at the compositor level is a workaround, not a fix. - It blocks downstream consumers from doing the right thing. A Wayland compositor that defensively waits on a sync_file gets a stub-fence pass-through with no actual gating; if the V4L2 driver ever has an out-of-band path that releases the buffer before finishing the write, there is no fence to gate on. What ---- Patch 1 adds: - struct dma_fence *release_fence to struct vb2_buffer - u64 dma_resv_fence_context + atomic64_t dma_resv_fence_seqno + spinlock_t dma_resv_fence_lock to struct vb2_queue - vb2_buffer_attach_release_fence(vb) — drivers call this from their buf_queue callback. Allocates a dma_fence on the queue's fence context, attaches it as DMA_RESV_USAGE_WRITE on each plane's dmabuf->resv. No-op for buffers without exported dmabufs. - vb2_buffer_done() extended to signal+put the fence if attached, so the producer's completion signal lands in the resv synchronously with the userspace DQBUF wakeup. Patches 2 and 3 add a single call to the helper from hantro_buf_queue and rga_buf_queue respectively. Both are demonstration drivers; other vb2 drivers can opt in incrementally with the same one-line change. Tested on --------- PineTab2 (RK3566 / Mali-G52 panfrost / mainline 6.19.10, this series backported), playing 1080p30 H.264 in chromium under KDE Plasma 6.6.4 Wayland. The test harness is the chromium-fourier patch series at https://github.com/marfrit/fourier — chromium plus a KWin patch that *previously bypassed* Transaction::watchDmaBuf because the kernel-side fence was stub-signalled. With this series applied, the bypass becomes unnecessary; KWin's fence wait completes correctly because the fence now signals when hantro completes the capture buffer write. End-to-end result before the kernel patch (chromium + Qt 6 patches + KWin watchDmaBuf bypass): 1080p30 H.264 plays through, ~81% combined chrome CPU, but the watchDmaBuf bypass weakens KWin's defenses against misbehaving clients. End-to-end result after the kernel patch (chromium + Qt 6 patches + plain unmodified KWin): 1080p30 H.264 plays through with the same CPU profile, KWin's watchDmaBuf wait completes within microseconds against the now-real producer fence, no defenses weakened. What's missing in this RFC -------------------------- - Other vb2-using drivers don't opt in. Each maintainer should look at their driver and decide. The hantro + rga patches show the shape; copying it to other drivers should be straightforward. - For drivers that have intermediate image-processor stages (e.g. CSI -> ISP -> user), the fence semantics across stage boundaries are out of scope here. This series only addresses the producer-to- userspace edge. - No selftest. videobuf2 doesn't have a great in-tree selftest harness for dmabuf flows; the validation is end-to-end at the userspace consumer level (KWin, in our case). Reviews especially welcome on: - The decision to make this opt-in per driver vs. automatic for all vb2-CAPTURE queues. Auto-on would force every driver to be audited; opt-in is incremental and safer but leaves the contract gap for drivers nobody touches. - Whether vb2_buffer_done is the right place to signal vs. an earlier hook (e.g. immediately after DMA-from-device finishes). For hantro the two are effectively the same; for drivers with asynchronous post-processing they may differ. - The choice of DMA_RESV_USAGE_WRITE — we are emitting the producer's write completion, so WRITE matches dma-buf documentation, but a sanity check is welcome. Cheers, Markus Markus Fritsche (3): media: videobuf2: add dma_resv release-fence helper media: hantro: attach dma_resv release fence at buf_queue media: rockchip-rga: attach dma_resv release fence at buf_queue .../media/common/videobuf2/videobuf2-core.c | 95 +++++++++++++++++++ drivers/media/platform/rockchip/rga/rga-buf.c | 10 ++ .../media/platform/verisilicon/hantro_v4l2.c | 12 +++ include/media/videobuf2-core.h | 29 ++++++ 4 files changed, 146 insertions(+) -- 2.47.3

2 months

[PATCH v2] dma-buf: heaps: use max3() in dma_heap_ioctl

by Thorsten Blum

Replace two nested max() calls with a single max3() in dma_heap_ioctl(). Reviewed-by: T.J. Mercier <tjmercier(a)google.com> Signed-off-by: Thorsten Blum <thorsten.blum(a)linux.dev> --- Changes in v2: - Include minmax.h as suggested by T.J. Mercier - v1: https://lore.kernel.org/lkml/20260427172519.417333-3-thorsten.blum@linux.de… --- drivers/dma-buf/dma-heap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index ac5f8685a649..d49188893608 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -13,6 +13,7 @@ #include <linux/err.h> #include <linux/export.h> #include <linux/list.h> +#include <linux/minmax.h> #include <linux/nospec.h> #include <linux/syscalls.h> #include <linux/uaccess.h> @@ -153,7 +154,7 @@ static long dma_heap_ioctl(struct file *file, unsigned int ucmd, in_size = 0; if ((ucmd & kcmd & IOC_OUT) == 0) out_size = 0; - ksize = max(max(in_size, out_size), drv_size); + ksize = max3(in_size, out_size, drv_size); /* If necessary, allocate buffer for ioctl argument */ if (ksize > sizeof(stack_kdata)) {

2 months

[PATCH] dma-buf: heaps: use max3() in dma_heap_ioctl

by Thorsten Blum

Replace two nested max() calls with a single max3() in dma_heap_ioctl(). Signed-off-by: Thorsten Blum <thorsten.blum(a)linux.dev> --- drivers/dma-buf/dma-heap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index ac5f8685a649..52eec2ebb2e8 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -153,7 +153,7 @@ static long dma_heap_ioctl(struct file *file, unsigned int ucmd, in_size = 0; if ((ucmd & kcmd & IOC_OUT) == 0) out_size = 0; - ksize = max(max(in_size, out_size), drv_size); + ksize = max3(in_size, out_size, drv_size); /* If necessary, allocate buffer for ioctl argument */ if (ksize > sizeof(stack_kdata)) {

2 months

Why Choose Block Recovery Team

by dominicmiles54＠gmail.com

With professionalism and integrity, Block Recovery Team assures that their clients get the finest possible help in retrieving their lost digital assets. With a staff of professionals dedicated to assisting individuals in navigating the recovery process, they provide 24 hour support to guarantee that customers receive timely and effective assistance when they need it the most. Testimonials from delighted clients demonstrate Block Recovery Team abilities in recovering lost digital assets, emphasizing their dedication to client satisfaction and good outcomes. NO UPFRONT FEES REQUIRED. Online presence: Block Recovery Team

2 months

[PATCH V13 0/7] Rust support for powerpc

by Mukesh Kumar Chaurasiya (IBM)

Enable experimental rust support for ppc64le and ppc32be. The patch for ppc32 has been provided by Link Mauve[1] and ppc64le support[2] has been merged over it. ppc32 needs some toolchain fixes mentioned in the patch `rust: Add PowerPC support` and the discussion for that is done here[1]. This has been tested on - powernv9 hardware - pseries P11 hardware - pseries(9, 10) qemu - powernv(9, 10) qemu - rustdoc on x86 and powerpc64le - rusttest on x86 and powerpc64le We are actively working with our LLVM team to get the target for ppc, ppc64 and ppc64le in the rust compiler. [1] https://lore.kernel.org/all/20260204030507.8203-1-linkmauve@linkmauve.fr [2] https://lore.kernel.org/all/20260204042417.83903-1-mkchauras@gmail.com Changelog: V12 -> V13: - Added a patch for fixing build issue on ppc32 by Link Mauve - Added another patch to fix a build issue in dma-buf - Added another patch to enforce minimum `rustc` version for powerpc V12: https://lore.kernel.org/all/20260421120958.190430-1-mkchauras@gmail.com/ V11 -> V12: - Rebased to mainline (rust/Makefile conflict resolved) V11: https://lore.kernel.org/all/20260417152253.2312961-1-mkchauras@gmail.com/ V10 -> V11: - Updated `rust/Makefile` - Not all libraries are move to `rust/host` directory now. Only proc_macro2, quote and syn are moved - Special handling for pin init is added. Details in commit - Removed mkdir for `rust/host`, this is now handled by toolchain. V10: https://lore.kernel.org/all/20260406200149.3727922-1-mkchauras@gmail.com/ V9 -> V10: - rust/Makefile updated with review comments from Miguel - Patch 1/4 updated with commit message and subject V9: https://lore.kernel.org/all/20260404121610.1956528-1-mkchauras@gmail.com/ V8 -> V9: - rust/Makefile updated with a directory instead of abspath V8: https://lore.kernel.org/all/20260403145308.1042622-1-mkchauras@gmail.com/ V7 -> V8: - rust/Makefile updated to separate host libraries from target V7: https://lore.kernel.org/all/20260329160254.2592207-1-mkchauras@gmail.com/ Changelog: V6 -> V7: - Documentation removed as powerpc is still under development - Added a fix for race condition in rust/Makefile V6: https://lore.kernel.org/all/20260210090023.2587534-1-mkchauras@gmail.com V5 -> V6: - Added a missing Tested by from Venkat which got missed since V3 - Support is marked as Maintained instead of experimental V5: https://lore.kernel.org/all/20260210053756.2088302-1-mkchauras@gmail.com V4 -> V5: - Removed a nested ifdef from PPC64 for Little endian toolchain V4: https://lore.kernel.org/all/20260209105456.1551677-1-mkchauras@gmail.com V3 -> V4: - Co-developed-by header added in patch 1 V3: https://lore.kernel.org/all/20260205180429.3280657-1-mkchauras@gmail.com V2 -> V3: - Splited HAVE_RUST in 2 lines - BINDGEN_TARGET_powerpc initialized before assigning the same to BINDGEN_TARGET V2: https://lore.kernel.org/all/20260204210125.613350-1-mkchauras@gmail.com V1 -> V2: - jump label fix for rust has been moved to a separate patch - PPC32 support has been taken - rust support has been marked experimental - target.json dependency has been removed - HAVE_RUST now depends on CPU_LITTLE_ENDIAN for PPC64 Link Mauve (2): rust: Make __udivdi3() and __umoddi3() panic rust: Add PowerPC support Mukesh Kumar Chaurasiya (IBM) (5): rust: Fix "multiple candidates for rmeta dependency core" error dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is disabled powerpc/jump_label: adjust inline asm to be consistent rust/powerpc: Set min rustc version for powerpc powerpc: Enable Rust for ppc64le arch/powerpc/Kconfig | 2 ++ arch/powerpc/Makefile | 7 ++++ arch/powerpc/include/asm/jump_label.h | 23 ++++++------ include/linux/dma-resv.h | 2 +- rust/Makefile | 52 +++++++++++++++++---------- rust/compiler_builtins.rs | 6 ++++ scripts/min-tool-version.sh | 6 +++- 7 files changed, 68 insertions(+), 30 deletions(-) -- 2.53.0

2 months

[PATCH v12 0/5] Rust bindings for gem shmem

by Lyude Paul

Most of this patch series has already been pushed upstream, this is just the second half of the patch series that has not been pushed yet + some additional changes which were required to implement changes requested by the mailing list. This patch series is originally from Asahi, previously posted by Daniel Almeida. The previous version of the patch series can be found here: https://patchwork.freedesktop.org/series/164580/ Branch with patches applied available here sure this builds: https://gitlab.freedesktop.org/lyudess/linux/-/commits/rust/gem-shmem This patch series applies on top of drm-rust-next Lyude Paul (5): rust: drm: gem: s/device::Device/Device/ for shmem.rs drm/gem/shmem: Introduce __drm_gem_shmem_free_sgt_locked() drm/gem/shmem: Export drm_gem_shmem_get_pages_sgt_locked() rust: drm: gem: Introduce shmem::SGTable rust: drm: gem: Add vmap functions to shmem bindings drivers/gpu/drm/drm_gem_shmem_helper.c | 48 ++- include/drm/drm_gem_shmem_helper.h | 2 + rust/kernel/drm/gem/shmem.rs | 557 ++++++++++++++++++++++++- 3 files changed, 593 insertions(+), 14 deletions(-) base-commit: a7a080bb4236ebe577b6776d940d1717912ff6dd -- 2.53.0

2 months, 1 week

(no subject)

by Alex Morgan

How Can I Recover My Lost Cryptocurrency, Hire Ghost Mystery Recovery Hacker Ghost Mystery Recovery Hacker delivered an excellent experience when I needed help recovering something I thought was permanently lost. From the start, their communication was clear, professional, and reassuring, which immediately made me feel more confident about the process. They took the time to understand my situation and explained each step in a way that was honest and easy to follow. What stood out most was their consistency and dedication. I was kept informed throughout, and they remained patient and responsive whenever I had questions. Their expertise was evident in the way they handled everything carefully and efficiently, without creating false expectations.The outcome exceeded what I had hoped for. They were able to successfully resolve my issue, which brought me a great sense of relief. It’s not often you come across a service that combines professionalism, transparency, and results so well. I would strongly recommend Ghost Mystery Recovery Hacker to anyone looking for reliable recovery support. Their commitment to helping clients and delivering real results truly sets them apart. Email address: support@ ghostmysteryrecovery. c om WhatsApp on (+44) 7480 061765 Website; ghostmysteryrecovery. c om

2 months, 1 week

(no subject)

by Alex Morgan

2 months, 1 week

(no subject)

by Alex Morgan

2 months, 1 week

Jump to page:

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

Linaro-mm-sig