DMA from PCIe -P4080DS

[appalanaidug]

Hello,

We are new to working on P4080DS and linux.

We are trying to access data from FPGA(configured as EP) through PCIe1 (root complex) in P4080DS board.

From linux user space, we are using "mmap64" function to access the FPGA data.

U-boot log shows the following lines: 

PCI host bridge /pcie@ffe200000 (primary) ranges:
MEM 0x0000000c00000000..0x0000000c1fffffff -> 0x00000000e0000000
IO 0x0000000ff8000000..0x0000000ff800ffff -> 0x0000000000000000
/pcie@ffe200000: PCICSRBAR @ 0xdf000000
/pcie@ffe200000: Setup 64-bit PCI DMA window
/pcie@ffe200000: DMA window size is 0xdf000000

Since "64-bit PCI DMA window" is set , how to access FPGA data through PCIe using DMA?

Any help is requested

Thank you in advance.

[ufedor]

According to the provided data local address 0xC00000000 corresponds to the FPGA memory.

So if you need to write data to the FPGA 0xC00000000 has to be the DMA destination address.

If you need to read data from the FPGA 0xC00000000 has to be the DMA source address.