* Kishon Vijay Abraham I <kishon@xxxxxx> [180827 03:06]: > Hi Tony, > > On Monday 20 August 2018 08:01 PM, Tony Lindgren wrote: > > * Kishon Vijay Abraham I <kishon@xxxxxx> [180808 06:35]: > >> On Tuesday 05 June 2018 07:35 PM, Rob Herring wrote: > >>> Really need 64-bit addresses and sizes? Use ranges to limit the > >>> address space if possible. > >> > >> We now have address-cells as <1>, > >> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/arch/arm64/boot/dts/ti/k3-am65.dtsi#n49 > >> > >> However each PCIe instance has 2 data regions and one of the regions > >> (PCIE0_CORE_CORE_DAT_SLV_PCIE_DAT1/PCIE1_CORE_CORE_DAT_SLV_PCIE_DAT1 specified > >> in the "MAIN Domain Memory Map" table of TRM http://www.ti.com/lit/pdf/spruid7) > >> is above the 32bit region and requires 2 cells to specify the start address. > >> This region is used to access MEM_SPACE of PCIe endpoint when operating in root > >> complex mode and access memory of PCI root complex when operating in endpoint mode. > >> > >> In order to describe this, should we change the address-cells back to <2> or do > >> you suggest any other alternatives? > > > > It's probably best to have the top level cbass interconnect use > > #size-cells = <2> and then have it's child interconnects have > > #size-cells = <1> if they don't need ranges above 4GB. > > PCIe has a region starting at 0x40_00000000 and size 4GB. We need 2 address > cells and 2 size cells to describe this no? Yes. > > BTW, what's the difference between all these three similar PCIE > > ranges? > > > > PCIE0_CORE_CORE_DAT_SLV_PCIE_CORE 0x0005500000 0x0005600000 1 MB > > PCIE1_CORE_CORE_DAT_SLV_PCIE_CORE 0x0005600000 0x0005700000 1 MB > > This is the register space for the two instances of PCIe controller. > > > > PCIE0_CORE_CORE_DAT_SLV_PCIE_DAT0 0x0010000000 0x0018000000 128 MB > > PCIE1_CORE_CORE_DAT_SLV_PCIE_DAT0 0x0018000000 0x0020000000 128 MB > > > > PCIE0_CORE_CORE_DAT_SLV_PCIE_DAT1 0x4000000000 0x4100000000 4 GB > > PCIE1_CORE_CORE_DAT_SLV_PCIE_DAT1 0x4100000000 0x4200000000 4 GB > > The above are regions which can be used by CPU/DMA to access the PCIe address > space. The mapping from the above regions to the PCIe address space will be > programmed in the PCIe controller. OK so not just somethng for dma-ranges but also accessible by the CPU. Regards, Tony
