On Mon, Nov 11, 2019 at 7:03 PM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > On Sun, Nov 10, 2019 at 10:43:48AM -0500, Peter Geis wrote: > > > I plugged in an i350 two port nic and examined the assigned address spaces. > > I've attached it below. > > Judging by the usage, I think this controller has enough address space > > for another two port NIC, and that's about it. > > I'm pretty sure now that the rk3399 controller just doesn't have the > > address space to map larger devices. > > I'm pretty sure the IOMMU would allow us to address system memory as > > pcie address space and overcome this limitation, but I don't know how > > to do that. > > I don't think you're out of MMIO space, at least in this instance. It > looks like you have 32MB available and the two-port NIC on bus 01 only > takes 5MB. > > The IOMMU is used for DMA (e.g., reads/writes initiated by the NIC), > while the MMIO space is used for CPU programmed I/O (reads/writes done > by the driver running on the CPU). > > > The address space for the nic is below: > > f8000000-f8ffffff : axi-base > > fa000000-fbdfffff : MEM > > 32MB. > > > fa000000-fa4fffff : PCI Bus 0000:01 > > 5MB. Just a note, this is not the device that triggered the bug. This is a i350 NIC, i posted it as a comparison to my original email. > > > fa000000-fa07ffff : 0000:01:00.0 > > fa000000-fa07ffff : igb > > fa080000-fa0fffff : 0000:01:00.0 > > fa100000-fa17ffff : 0000:01:00.1 > > fa100000-fa17ffff : igb > > fa180000-fa1fffff : 0000:01:00.1 > > fa200000-fa27ffff : 0000:01:00.0 > > fa280000-fa2fffff : 0000:01:00.0 > > fa300000-fa37ffff : 0000:01:00.1 > > fa380000-fa3fffff : 0000:01:00.1 > > fa400000-fa403fff : 0000:01:00.0 > > fa400000-fa403fff : igb > > fa404000-fa407fff : 0000:01:00.1 > > fa404000-fa407fff : igb > > fd000000-fdffffff : f8000000.pcie
