Re: [RESEND PATCH V10 XDMA 0/2] xilinx XDMA driver

From: Martin Tůma
Date: Wed Nov 30 2022 - 00:42:17 EST


On 22. 11. 22 18:21, Lizhi Hou wrote:
Hello,

This V10 of patch series is to provide the platform driver to support the
Xilinx XDMA subsystem. The XDMA 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. It also provides up to 16 user
interrupt wires to user logic that generate interrupts to the host.

+-------+ +-------+ +-----------+
PCIe | | | | | |
Tx/Rx | | | | AXI | |
<=======> | PCIE | <===> | XDMA | <====>| User Logic|
| | | | | |
+-------+ +-------+ +-----------+

The XDMA has been used for Xilinx Alveo PCIe devices.
And it is also integrated into Versal ACAP DMA and Bridge Subsystem.
https://www.xilinx.com/products/boards-and-kits/alveo.html
https://docs.xilinx.com/r/en-US/pg344-pcie-dma-versal/Introduction-to-the-DMA-and-Bridge-Subsystems

The device driver for any FPGA based PCIe device which leverages XDMA can
call the standard dmaengine APIs to discover and use the XDMA subsystem
without duplicating the XDMA driver code in its own driver.

Changes since v9:
- Cleanup code based on review comments.

Changes since v8:
- Fixed test robot failure on s390.

Changes since v7:
- Used pci device pointer for dma_pool_create().

Changes since v6:
- Fixed descriptor filling bug.

Changes since v5:
- Modified user logic interrupt APIs to handle user logic IP which does not
have its own register to enable/disable interrupt.
- Clean up code based on review comments.

Changes since v4:
- Modified user logic interrupt APIs.

Changes since v3:
- Added one patch to support user logic interrupt.

Changes since v2:
- Removed tasklet.
- Fixed regression bug introduced to V2.
- Test Robot warning.

Changes since v1:
- Moved filling hardware descriptor to xdma_prep_device_sg().
- Changed hardware descriptor enum to "struct xdma_hw_desc".
- Minor changes from code review comments.

Lizhi Hou (2):
dmaengine: xilinx: xdma: Add xilinx xdma driver
dmaengine: xilinx: xdma: Add user logic interrupt support

MAINTAINERS | 11 +
drivers/dma/Kconfig | 14 +
drivers/dma/xilinx/Makefile | 1 +
drivers/dma/xilinx/xdma-regs.h | 173 ++++
drivers/dma/xilinx/xdma.c | 1004 ++++++++++++++++++++++++
include/linux/dma/amd_xdma.h | 16 +
include/linux/platform_data/amd_xdma.h | 34 +
7 files changed, 1253 insertions(+)
create mode 100644 drivers/dma/xilinx/xdma-regs.h
create mode 100644 drivers/dma/xilinx/xdma.c
create mode 100644 include/linux/dma/amd_xdma.h
create mode 100644 include/linux/platform_data/amd_xdma.h


Hi,
I see that there is no response for more than two weeks on this driver, is there some problem with it? The XDMA driver is required for our mgb4
v4l2 driver to work:

https://patchwork.kernel.org/project/linux-media/patch/20221123140431.4730-2-tumic@xxxxxxxxxx/

The patches not being included in the kernel block the progress on our driver as it naturally fails to compile and as a result the willingness to deal with our patch is quiet low among the v4l2 people... Thanks for any help.

Martin Tůma