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. In this version 2, I have (hopefully) taken into account the comments from Bjorn Helgaas and Russell King. Here are the changes: - 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 (2): PCI: Introduce PCI bridge emulated config space common logic 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 | 375 +++++++++---------------------- drivers/pci/pci-bridge-emul.c | 408 ++++++++++++++++++++++++++++++++++ drivers/pci/pci-bridge-emul.h | 124 +++++++++++ 7 files changed, 770 insertions(+), 272 deletions(-) create mode 100644 drivers/pci/pci-bridge-emul.c create mode 100644 drivers/pci/pci-bridge-emul.h -- 2.14.4
