The Smart Data Accelerator Interface (SDXI) is a vendor-neutral architecture for memory-to-memory data movement offload designed for kernel bypass and virtualization. General information on SDXI may be found at: https://www.snia.org/sdxi This submission adds a driver with basic support for PCIe-hosted SDXI 1.0 implementations and includes a DMA engine provider. It is very much a work in progress. Among other issues, the DMA provider code only supports single-threaded polled mode, and context management should use better data structures. While we're addressing those shortcomings, we'd appreciate any feedback on: * Where the code should live. SDXI entails a fair amount of code for context and descriptor management, and we expect to eventually add a character device ABI for user space access. Should all of this go in drivers/dma/sdxi? * Whether the DMA engine provider should use virt-dma/vchan. SDXI submission queues can be almost arbitrarily large, and I'm not sure putting a software queue in front of that makes sense. Planned future SDXI work (out of scope for this series): * Character device for user space access. We are evaluating the uacce framework for this. * Support for operation types to be added in future SDXI revisions. * Greater configurability for control structures, e.g. descriptor ring size. The latest released version of the SDXI specification is 1.0: https://www.snia.org/sites/default/files/technical-work/sdxi/release/SNIA-SDXI-Specification-v1.0a.pdf Draft versions of future SDXI specifications in development may be found at: https://www.snia.org/tech_activities/publicreview#sdxi --- Nathan Lynch (13): PCI: Add SNIA SDXI accelerator sub-class dmaengine: sdxi: Add control structure definitions dmaengine: sdxi: Add descriptor encoding and unit tests dmaengine: sdxi: Add MMIO register definitions dmaengine: sdxi: Add software data structures dmaengine: sdxi: Add error reporting support dmaengine: sdxi: Import descriptor enqueue code from spec dmaengine: sdxi: Context creation/removal, descriptor submission dmaengine: sdxi: Add core device management code dmaengine: sdxi: Add PCI driver support dmaengine: sdxi: Add DMA engine provider dmaengine: sdxi: Add Kconfig and Makefile MAINTAINERS: Add entry for SDXI driver MAINTAINERS | 7 + drivers/dma/Kconfig | 2 + drivers/dma/Makefile | 1 + drivers/dma/sdxi/.kunitconfig | 4 + drivers/dma/sdxi/Kconfig | 23 ++ drivers/dma/sdxi/Makefile | 17 ++ drivers/dma/sdxi/context.c | 547 ++++++++++++++++++++++++++++++++++++ drivers/dma/sdxi/context.h | 28 ++ drivers/dma/sdxi/descriptor.c | 197 +++++++++++++ drivers/dma/sdxi/descriptor.h | 107 +++++++ drivers/dma/sdxi/descriptor_kunit.c | 181 ++++++++++++ drivers/dma/sdxi/device.c | 401 ++++++++++++++++++++++++++ drivers/dma/sdxi/dma.c | 409 +++++++++++++++++++++++++++ drivers/dma/sdxi/dma.h | 12 + drivers/dma/sdxi/enqueue.c | 136 +++++++++ drivers/dma/sdxi/enqueue.h | 16 ++ drivers/dma/sdxi/error.c | 340 ++++++++++++++++++++++ drivers/dma/sdxi/error.h | 16 ++ drivers/dma/sdxi/hw.h | 249 ++++++++++++++++ drivers/dma/sdxi/mmio.h | 92 ++++++ drivers/dma/sdxi/pci.c | 216 ++++++++++++++ drivers/dma/sdxi/sdxi.h | 206 ++++++++++++++ include/linux/pci_ids.h | 1 + 23 files changed, 3208 insertions(+) --- base-commit: c17b750b3ad9f45f2b6f7e6f7f4679844244f0b9 change-id: 20250813-sdxi-base-73d7c9fdce57 Best regards, -- Nathan Lynch <nathan.lynch@xxxxxxx>
