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Diffstat (limited to 'Documentation/misc-devices')
| -rw-r--r-- | Documentation/misc-devices/index.rst | 1 | ||||
| -rw-r--r-- | Documentation/misc-devices/mrvl_cn10k_dpi.rst | 52 |
2 files changed, 53 insertions, 0 deletions
diff --git a/Documentation/misc-devices/index.rst b/Documentation/misc-devices/index.rst index 2d0ce9138588..8c5b226d8313 100644 --- a/Documentation/misc-devices/index.rst +++ b/Documentation/misc-devices/index.rst @@ -21,6 +21,7 @@ fit into other categories. isl29003 lis3lv02d max6875 + mrvl_cn10k_dpi oxsemi-tornado pci-endpoint-test spear-pcie-gadget diff --git a/Documentation/misc-devices/mrvl_cn10k_dpi.rst b/Documentation/misc-devices/mrvl_cn10k_dpi.rst new file mode 100644 index 000000000000..a75e372723d8 --- /dev/null +++ b/Documentation/misc-devices/mrvl_cn10k_dpi.rst @@ -0,0 +1,52 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=============================================== +Marvell CN10K DMA packet interface (DPI) driver +=============================================== + +Overview +======== + +DPI is a DMA packet interface hardware block in Marvell's CN10K silicon. +DPI hardware comprises a physical function (PF), its virtual functions, +mailbox logic, and a set of DMA engines & DMA command queues. + +DPI PF function is an administrative function which services the mailbox +requests from its VF functions and provisions DMA engine resources to +it's VF functions. + +mrvl_cn10k_dpi.ko misc driver loads on DPI PF device and services the +mailbox commands submitted by the VF devices and accordingly initializes +the DMA engines and VF device's DMA command queues. Also, driver creates +/dev/mrvl-cn10k-dpi node to set DMA engine and PEM (PCIe interface) port +attributes like fifo length, molr, mps & mrrs. + +DPI PF driver is just an administrative driver to setup its VF device's +queues and provisions the hardware resources, it cannot initiate any +DMA operations. Only VF devices are provisioned with DMA capabilities. + +Driver location +=============== + +drivers/misc/mrvl_cn10k_dpi.c + +Driver IOCTLs +============= + +:c:macro::`DPI_MPS_MRRS_CFG` +ioctl that sets max payload size & max read request size parameters of +a pem port to which DMA engines are wired. + + +:c:macro::`DPI_ENGINE_CFG` +ioctl that sets DMA engine's fifo sizes & max outstanding load request +thresholds. + +User space code example +======================= + +DPI VF devices are probed and accessed from user space applications using +vfio-pci driver. Below is a sample dpi dma application to demonstrate on +how applications use mailbox and ioctl services from DPI PF kernel driver. + +https://github.com/MarvellEmbeddedProcessors/dpi-sample-app |