On Thu, Oct 18, 2018 at 05:37:15PM +0200, Thomas Petazzoni wrote: > Hello, > > The pci-mvebu driver already contains some logic to emulate a root > port PCI bridge configuration space. It turns out that we have a > similar need for the pci-aardvark driver. Instead of duplicating the > same logic in two drivers, this patch series starts by adding a small > common infrastructure that helps emulate a root port PCI bridge config > space, converts pci-mvebu to use it, and finally extends pci-aardvark > to use it as well. > > Thanks to this, Marvell Armada 3720 based systems, which use the > Aarkvark PCI controller, will have better PCI support, by having a > root port PCI bridge exposed. > > The emulated PCI bridge common logic is a proposal, I very much > welcome comments and suggestions. Also, if you feel that adding a > common logic for only two drivers is too early, I'm fine with > duplicating a bit of code betwen pci-mvebu and pci-aardvark. > > Changes v2 -> v3: > > - Address the FIXME comment that was pointed out by Russell. In fact > the |= pcie_devctl was not needed, because pcie_devctl is always > zero. To fix this, an additional commit was added to the series to > drop the use of unneeded fields in the PCI Express capability block > emulation in pci-mvebu. > > - Drop some more code from pci-mvebu that was used to prevent messing > up with W1C bits, because this is now already taken care of by the > common bridge emulation logic. > > - Fixed the commit log of "PCI: mvebu: Convert to PCI emulated bridge > config space" according to Lorenzo comments. > > - Use PCI_STD_HEADER_SIZEOF when defining PCI_BRIDGE_CONTROL, as > suggested by Bjorn. > > - Added Bjorn Acked-by and Russell Reviewed-by on the patch adding > the common logic. > > Changes v1 -> v2: > > - Rebased to 4.19-rc1 > > - The functions implementing the config space read/write emulation > now have the knowledge of which registers/bits are read-only, > read-write, reserved and write-1-to-clear, and behave according to > this information. > > - I have renamed the function to use conf_read() and conf_write() > suffixes, as suggested by Bjorn. > > - The whole thing is now named pci-bridge-emul instead of > pci-sw-bridge (and of course all functions, types and macros were > changed accordingly), as Bjorn wasn't happy about pci-sw-bridge. > > - The header file was moved into drivers/pci (instead of being in > include/linux). > > Thanks a lot in advance for your review and feedback. > > Best regards, > > Thomas Petazzoni > > Thomas Petazzoni (3): > PCI: Introduce PCI bridge emulated config space common logic > PCI: mvebu: Drop unused PCI express capability code > PCI: mvebu: Convert to PCI emulated bridge config space > > Zachary Zhang (1): > PCI: aardvark: Implement emulated root PCI bridge config space > > drivers/pci/Kconfig | 3 + > drivers/pci/Makefile | 1 + > drivers/pci/controller/Kconfig | 2 + > drivers/pci/controller/pci-aardvark.c | 129 ++++++++++- > drivers/pci/controller/pci-mvebu.c | 384 +++++++++----------------------- > drivers/pci/pci-bridge-emul.c | 408 ++++++++++++++++++++++++++++++++++ > drivers/pci/pci-bridge-emul.h | 124 +++++++++++ > 7 files changed, 764 insertions(+), 287 deletions(-) > create mode 100644 drivers/pci/pci-bridge-emul.c > create mode 100644 drivers/pci/pci-bridge-emul.h I have applied the series with Bjorn and Russell ACKs to pci/controller-misc, tentatively for v4.20. Thanks ! Lorenzo
