Hi Lizhi, Nishad, On Thu, Apr 18, 2024 at 7:51 PM Lizhi Hou <lizhi.hou@xxxxxxx> wrote: > From: Nishad Saraf <nishads@xxxxxxx> > > Adds driver to enable PCIe board which uses AMD QDMA (the Queue-based > Direct Memory Access) subsystem. For example, Xilinx Alveo V70 AI > Accelerator devices. > https://www.xilinx.com/applications/data-center/v70.html > > The QDMA subsystem is used in conjunction with the PCI Express IP block > to provide high performance data transfer between host memory and the > card's DMA subsystem. > > +-------+ +-------+ +-----------+ > PCIe | | | | | | > Tx/Rx | | | | AXI | | > <=======> | PCIE | <===> | QDMA | <====>| User Logic| > | | | | | | > +-------+ +-------+ +-----------+ > > The primary mechanism to transfer data using the QDMA is for the QDMA > engine to operate on instructions (descriptors) provided by the host > operating system. Using the descriptors, the QDMA can move data in both > the Host to Card (H2C) direction, or the Card to Host (C2H) direction. > The QDMA provides a per-queue basis option whether DMA traffic goes > to an AXI4 memory map (MM) interface or to an AXI4-Stream interface. > > The hardware detail is provided by > https://docs.xilinx.com/r/en-US/pg302-qdma > > Implements dmaengine APIs to support MM DMA transfers. > - probe the available DMA channels > - use dma_slave_map for channel lookup > - use virtual channel to manage dmaengine tx descriptors > - implement device_prep_slave_sg callback to handle host scatter gather > list > > Signed-off-by: Nishad Saraf <nishads@xxxxxxx> > Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxx> Thanks for your patch, which is now commit 73d5fc92a11cacb7 ("dmaengine: amd: qdma: Add AMD QDMA driver") in dmaengine/next. > --- /dev/null > +++ b/drivers/dma/amd/Kconfig > @@ -0,0 +1,14 @@ > +# SPDX-License-Identifier: GPL-2.0-only > + > +config AMD_QDMA > + tristate "AMD Queue-based DMA" > + depends on HAS_IOMEM Any other subsystem or platform dependencies, to prevent asking the user about this driver when configuring a kernel for a system which cannot possibly have this hardware? E.g. depends on PCI, or can this be used with other transports than PCIe? > --- /dev/null > +++ b/drivers/dma/amd/qdma/qdma-comm-regs.c > +static struct platform_driver amd_qdma_driver = { > + .driver = { > + .name = "amd-qdma", Which code is responsible for creating "amd-qdma" platform devices? > + }, > + .probe = amd_qdma_probe, > + .remove_new = amd_qdma_remove, > +}; > + > +module_platform_driver(amd_qdma_driver); Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
