PCIe inbound BAR4 doesn't work

Autonomous Machines Jetson & Embedded Systems Jetson AGX Xavier
1

pcie inbound BAR0 works, but not for BAR4

int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int index, int bar,
u64 cpu_addr, enum dw_pcie_as_type as_type)

dw_pcie_prog_inbound_atu(pci, 0, BAR0, 0x100000000, DW_PCIE_AS_MEM);
dw_pcie_prog_inbound_atu(pci, 2, BAR4, 0x140000000, DW_PCIE_AS_MEM);

lspci -s 0000:1d:00.0 -xv
0000:1d:00.0 RAM memory: NVIDIA Corporation Device 0002
Flags: fast devsel, NUMA node 0
Memory at 387f00000000 (64-bit, prefetchable) [size=1G]
Memory at 387f60000000 (64-bit, prefetchable) [size=128K]
Memory at 387f40000000 (64-bit, prefetchable) [size=512M]

@jetson
busybox devmem 0x140000000
0xAE5BFACD

@pcie host
busybox devmem 0x387f40000000
0x00000688

thanks.

3

it seems that the BAR4 is dedicated for some purpose.

even though I didn’t config BAR4 and setup inbound.
lspci -s 0000:1d:00.0 -xv
0000:1d:00.0 RAM memory: NVIDIA Corporation Device 0002
Flags: fast devsel, NUMA node 0
Memory at 387e80000000 (64-bit, prefetchable) [size=2G]
Memory at 387f00000000 (64-bit, prefetchable) [size=128K]
Memory at e0100000 (64-bit, non-prefetchable) [size=1M]

@pcie host
busybox devmem 0xe0100000
0x00000688