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. Thanks in advance for your time. Best regards, Sergio Paracuellos > > Changes in v2: > - re-do commit messages for PCI patch as Bjorn pointed out in previous series. > - Add Bjorn's Acked-by for PCI subsystem patch. > - Re-do commit message of MIPS 'pci_remap_iospace()' patch to align with changes > in the PCI patch (s/architecture dependent/architecture-specific/) > - Add Fixes-by tag for MIPS set PCI_IOBASE patch. > > [0]: https://www.spinics.net/lists/kernel/msg4051474.html > [1]: https://lkml.org/lkml/2021/9/22/6 > Sergio Paracuellos (6): > Revert "MIPS: ralink: don't define PC_IOBASE but increase > IO_SPACE_LIMIT" > Revert "staging: mt7621-pci: set end limit for 'ioport_resource'" > MIPS: ralink: set PCI_IOBASE to 'mips_io_port_base' > PCI: Allow architecture-specific pci_remap_iospace() > MIPS: implement architecture-specific 'pci_remap_iospace()' > staging: mt7621-pci: properly adjust base address for the IO window > > arch/mips/include/asm/mach-ralink/spaces.h | 4 +++- > arch/mips/include/asm/pci.h | 2 ++ > arch/mips/pci/pci-generic.c | 14 ++++++++++++++ > drivers/pci/pci.c | 2 ++ > drivers/staging/mt7621-pci/pci-mt7621.c | 4 +--- > 5 files changed, 22 insertions(+), 4 deletions(-) > > -- > 2.25.1 >
