This is my first take on using the DRM Rust abstractions [1] to convert a DRM driver, written originally in C, to Rust. This patchset consists of a conversion of the vgem driver to a DRM Rust driver. This new driver has the exactly same functionalities of the original C driver, but takes advantages of all the Rust features. These patches are based primarily on the Rust DRM abstractions [1], sent as a RFC to the mailing list last week. Also, it depends on some Device abstractions [2] and on the Timer abstraction [3] developed by Boqun Feng. This patchset introduces some changes to the DRM abstractions proposed in [1] and also introduces a new abstraction to DMA reservation. Finally, introduces a fully functional vgem driver written in Rust. * Patch #1: Introduces a safe abstraction to the DMA Reservation. * Patch #2 - #5: Introduces some increments to the DRM abstractions, adding methods and exposing attributes. * Patch #6: Makes an adaptation to the UAPI, in order to be interpreted by bindgen. * Patch #7 - #8: Introduces the vgem driver. * Patch #9: Makes it possible to use the kernel::declare_drm_ioctls! macro. The driver was tested with IGT, using the tests `vgem_basic`, `vgem_slow` and `dmabuf_sync_file`. Also, I incremented some invalid tests to `vgem_basic` [4] to assure the proper error handling of the driver. A branch with all the dependencies and ready for compilation is available at [5]. Note that patch #8 is necessary to deal with the current kernel::declare_drm_ioctls! macro. Currently, the macro kernel::declare_drm_ioctls! considers that the IOCTLs are in the right order and there are no gaps, which is not true for vgem. The vgem IOCTLs starts at 0x01, so there is a gap for IOCTL 0x00. To bypass this problem I'm currently using a dummy IOCTL as IOCTL 0x00, but this solution should be temporary. I would love to hear suggestions on how to address this problem. Any suggestions and SAFETY reviews are welcomed! [1] https://lore.kernel.org/dri-devel/20230307-rust-drm-v1-0-917ff5bc80a8@xxxxxxxxxxxxx/T/ [2] https://github.com/Rust-for-Linux/linux/pull/982 [3] https://github.com/fbq/linux-rust/commit/c31a2a3ce7420b43bda2c6f1b43227baf0d13661 [4] https://patchwork.freedesktop.org/series/114912/ [5] https://github.com/mairacanal/linux/tree/vgem/wip-dma Best Regards, - Maíra Canal Maíra Canal (9): rust: dma_resv: add DMA Reservation abstraction rust: drm: gem: add method to return DmaResv from GEMObject rust: dma_fence: add method to return an indication if the fence is signaled rust: dma_fence: expose the fence's seqno publically rust: drm: gem: shmem: set map_wc on gem_create_object callback drm/vgem: move IOCTLs numbers to enum drm/rustgem: implement a Rust version of VGEM drm/rustgem: implement timeout to prevent hangs drm/rustgem: create dummy IOCTL with number 0x00 drivers/gpu/drm/Kconfig | 11 +++ drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/rustgem/Makefile | 3 + drivers/gpu/drm/rustgem/fence.rs | 83 ++++++++++++++++++ drivers/gpu/drm/rustgem/file.rs | 143 +++++++++++++++++++++++++++++++ drivers/gpu/drm/rustgem/gem.rs | 31 +++++++ drivers/gpu/drm/rustgem/vgem.rs | 105 +++++++++++++++++++++++ include/uapi/drm/vgem_drm.h | 11 ++- rust/bindings/bindings_helper.h | 2 + rust/helpers.c | 25 ++++++ rust/kernel/dma_fence.rs | 12 +++ rust/kernel/dma_resv.rs | 75 ++++++++++++++++ rust/kernel/drm/gem/mod.rs | 7 ++ rust/kernel/drm/gem/shmem.rs | 5 ++ rust/kernel/lib.rs | 1 + 15 files changed, 513 insertions(+), 2 deletions(-) create mode 100644 drivers/gpu/drm/rustgem/Makefile create mode 100644 drivers/gpu/drm/rustgem/fence.rs create mode 100644 drivers/gpu/drm/rustgem/file.rs create mode 100644 drivers/gpu/drm/rustgem/gem.rs create mode 100644 drivers/gpu/drm/rustgem/vgem.rs create mode 100644 rust/kernel/dma_resv.rs -- 2.39.2
