On Sun, Oct 03, 2021 at 06:21:21PM +0200, Sergio Paracuellos wrote: > Hi Greg, > > On Sat, Sep 25, 2021 at 10:32 PM Sergio Paracuellos > <sergio.paracuellos@xxxxxxxxx> wrote: > > > > MIPs ralink need a special tratement regarding the way it handles PCI IO > > resources. On MIPS I/O ports are memory mapped, so we access them using normal > > load/store instructions. MIPS 'plat_mem_setup()' function does a call to > > 'set_io_port_base(KSEG1)'. There, variable 'mips_io_port_base' > > is set then using this address which is a virtual address to which all > > ports are being mapped. Ralink I/O space has a mapping of bus address > > equal to the window into the mmio space, with an offset of IO start range > > cpu address. This means that to have this working we need: > > - linux port numbers in the range 0-0xffff. > > - pci port numbers in the range 0-0xffff. > > - io_offset being zero. > > > > These means at the end to have bus address 0 mapped to IO range cpu address. > > We need a way of properly set 'mips_io_port_base' with a virtually mapped > > value of the IO cpu address. > > > > This series do the following approach: > > 1) Revert two bad commit from a previous attempt of make this work [0]. > > 2) Set PCI_IOBASE to mips 'mips_io_port_base'. > > 3) Allow architecture dependent 'pci_remap_iospace'. > > 4) Implement 'pci_remap_iospace' for MIPS. > > 5) Be sure IOBASE address for IO window is set with correct value. > > > > More context about this series appoach in this mail thread [1]. > > > > Patches related with reverts are from this merge cycle so they are only > > added to the staging git tree. So to have all stuff together I'd like to > > get everybody Ack's to get all of this series through staging tree if > > possible :). > > > > Thanks in advance for your time. > > > > Changes in v3: > > - Collect Arnd's Acked-by for the patches. > > - Be sure IO resource start address is zero and WARN_ONCE if it is not > > on MIPS pci_remap_iospace() patch. Also make use of 'resource_size' > > instead of do the logic explicitly again. > > I think nothing is missing to get this added through the staging tree. Great, thanks for sticking with this, will go queue it up now. greg k-h
