Re: [PATCH 0/3] PCI/gic-v3-its: Add support for same ITS device ID for multiple PCIe devices

From: Marc Zyngier
Date: Mon Sep 20 2021 - 05:14:52 EST


On Mon, 20 Sep 2021 07:41:30 +0100,
Kishon Vijay Abraham I <kishon@xxxxxx> wrote:
>
> AM64 has an issue in that it doesn't trigger interrupt if the address
> in the *pre_its_window* is not aligned to 8-bytes (this is due to an
> invalid bridge configuration in HW).
>
> This means there will not be interrupts for devices with PCIe
> requestor ID 0x1, 0x3, 0x5..., as the address in the pre-ITS window
> would be 4 (1 << 2), 12 (3 << 2), 20 (5 << 2) respectively which are
> not aligned to 8-bytes.
>
> The DT binding has specified "msi-map-mask" using which multiple PCIe
> devices could be made to use the same ITS device ID.
>
> Add support in irq-gic-v3-its-pci-msi.c for such cases where multiple
> PCIe devices are using the same ITS device ID.
>
> Kishon Vijay Abraham I (3):
> PCI: Add support in pci_walk_bus() to invoke callback matching RID
> PCI: Export find_pci_root_bus()
> irqchip/gic-v3-its: Include "msi-map-mask" for calculating nvecs
>
> drivers/irqchip/irq-gic-v3-its-pci-msi.c | 21 ++++++++++++++++++++-
> drivers/pci/bus.c | 13 +++++++++----
> drivers/pci/host-bridge.c | 3 ++-
> include/linux/pci.h | 8 ++++++--
> 4 files changed, 37 insertions(+), 8 deletions(-)

What I don't see in this series is how you address the other part of
the problem, which is your reuse of the Socionext hack. Please post a
complete series addressing all the issues for this HW.

Thanks,

M.

--
Without deviation from the norm, progress is not possible.