[PATCH 0/4] PCI SMC conduit, now with DT support

Jeremy Linton jeremy.linton at arm.com
Mon Jul 25 09:39:01 PDT 2022


This is a rebase of the later revisions of [1], but refactored
slightly to add a DT method as well. It has all the same advantages of
the ACPI method (putting HW quirks in the firmware rather than the
kernel) but now applied to a 'pci-host-smc-generic' compatible
property which extends the pci-host-generic logic to handle cases
where the PCI Config region isn't ECAM compliant. With this in place,
and firmware managed clock/phy/etc its possible to run the generic
driver on hardware that isn't what one would consider standards
compliant PCI root ports.

The DT code was tested on the RPi4, where the ACPI/SMC is upstream in
TF-A and EDK2. On that platform the PCIe works as expected utilizing
the generic host driver rather than the pcie-brcmstb driver.

[1] https://lkml.org/lkml/2021/1/4/1255

Jeremy Linton (4):
  arm64: smccc: Add PCI SMCCCs
  arm64: PCI: Enable SMC conduit
  PCI: host-generic: Add firmware managed config ops
  dt-bindings: PCI: Note the use of pci-host-smc-generic

 .../bindings/pci/host-generic-pci.yaml        |  24 +++-
 arch/arm64/kernel/pci.c                       | 109 ++++++++++++++++++
 drivers/pci/controller/pci-host-common.c      |  34 ++++--
 drivers/pci/controller/pci-host-generic.c     |   6 +
 include/linux/arm-smccc.h                     |  29 +++++
 5 files changed, 186 insertions(+), 16 deletions(-)

-- 
2.37.1




More information about the linux-arm-kernel mailing list