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Registered: ‎06-10-2019

devmem failure to read on PCie BARs

Hi,

I am using ZCU106 , implemented Rootcomplex(xdma AXI Bridge) on PL, and attached PCIe EP device. It correctly enumerate wihtout any problem(I ink so) : Logs are here:

[ 4.274313] xilinx-pcie 400000000.axi-pcie: Using MSI FIFO mode
[ 4.279796] xilinx-pcie 400000000.axi-pcie: Base address 536870912
[ 4.285895] xilinx-pcie 400000000.axi-pcie: PCIe Link is UP
[ 4.291447] xilinx-pcie 400000000.axi-pcie: host bridge /amba_pl@0/axi-pcie@a0000000 ranges:
[ 4.299827] xilinx-pcie 400000000.axi-pcie: No bus range found for /amba_pl@0/axi-pcie@a0000000, using [bus 00-ff]
[ 4.310297] xilinx-pcie 400000000.axi-pcie: MEM 0xa0000000..0xafffffff -> 0x00000000
[ 4.318250] xilinx-pcie 400000000.axi-pcie: PCI host bridge to bus 0000:00
[ 4.324999] pci_bus 0000:00: root bus resource [bus 00-ff]
[ 4.330449] pci_bus 0000:00: root bus resource [mem 0xa0000000-0xafffffff] (bus address [0x00000000-0x0fffffff])
[ 4.342773] pci 0000:00:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring
[ 4.350772] pci 0000:01:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring
[ 4.359014] pci 0000:02:01.0: bridge configuration invalid ([bus 00-00]), reconfiguring
[ 4.364452] pci 0000:02:02.0: bridge configuration invalid ([bus 00-00]), reconfiguring
[ 4.376848] pci 0000:00:00.0: BAR 8: assigned [mem 0xa0000000-0xa00fffff]
[ 4.379156] pci 0000:01:00.0: BAR 8: assigned [mem 0xa0000000-0xa00fffff]
[ 4.385901] pci 0000:02:01.0: BAR 8: assigned [mem 0xa0000000-0xa00fffff]
[ 4.392650] pci 0000:03:00.0: BAR 0: assigned [mem 0xa0000000-0xa007ffff]
[ 4.399399] pci 0000:03:00.0: BAR 1: assigned [mem 0xa0080000-0xa0080fff]
[ 4.406146] pci 0000:03:00.0: BAR 2: assigned [mem 0xa0081000-0xa0081fff]
[ 4.412893] pci 0000:03:00.0: BAR 3: assigned [mem 0xa0082000-0xa0082fff]
[ 4.419641] pci 0000:03:00.0: BAR 4: assigned [mem 0xa0083000-0xa0083fff]
[ 4.426389] pci 0000:02:01.0: PCI bridge to [bus 03]
[ 4.431320] pci 0000:02:01.0: bridge window [mem 0xa0000000-0xa00fffff]
[ 4.438070] pci 0000:02:02.0: PCI bridge to [bus 04]
[ 4.443005] pci 0000:01:00.0: PCI bridge to [bus 02-04]
[ 4.448188] pci 0000:01:00.0: bridge window [mem 0xa0000000-0xa00fffff]
[ 4.454939] pci 0000:00:00.0: PCI bridge to [bus 01-04]
[ 4.460124] pci 0000:00:00.0: bridge window [mem 0xa0000000-0xa00fffff]
[ 4.466943] Error: Driver 'xilinx-pcie' is already registered, aborting...
[ 4.474754] ps_pcie_dma init()

 

I cant access any of BARs address which is 0xa0000000 from my driver so decided to use devmem for simple rd/wr,

devmem 0xA0000000 32 

[ 3737.887887] xilinx-pcie 400000000.axi-pcie: Slave unsupported request
Bus error

Note: (1) excluded "filter access to /dev/mem" in kernel configuration

         (2) xdma ip configuration in PL, AXI to PCIe transalation: 0xa0000000 , I tried with 0x0 too, doesnt make any difference.

Let me know i fyou need any more information. I dont really understand why devmem cant access 0xA0000000. It does rd/wr on rootcomplex register which is on AXI_LITE bus.   

 

xdma_pic.PNG
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