Re: [PATCH 00/13] PCI: MSI: Getting rid of msi_controller, and other cleanups

Bjorn Helgaas
2021-03-10T19:30:41Z

On Thu, Feb 25, 2021 at 03:10:10PM +0000, Marc Zyngier wrote:
> The msi_controller data structure was the first attempt at treating
> MSIs like any other interrupt. We replaced it a few years ago with the
> generic MSI framework, but as it turns out, some older drivers are
> still using it.
>
> This series aims at converting these stragglers, drop msi_controller,
> and fix some other nits such as having ways for a host bridge to
> advertise whether it supports MSIs or not.
>
> A few notes:
>
> - The Tegra patch is the result of back and forth work with Thierry: I
> wrote the initial patch, which didn't work (I didn't have any HW at
> the time). Thierry made it work, and I subsequently fixed a couple
> of bugs/cleanups. I'm responsible for the result, so don't blame
> Thierry for any of it! FWIW, I'm now running a Jetson TX2 with its
> root fs over NVME, and MSIs are OK.
>
> - RCAR is totally untested, though Marek had a go at a previous
> version. More testing required.
>
> - The xilinx stuff is *really* untested. Paul, if you have a RISC-V
> board that uses it, could you please give it a go? Michal, same
> thing for the stuff you have at hand...
>
> - hyperv: I don't have access to such hypervisor, and no way to test
> it. Help welcomed.
>
> - The patches dealing with the advertising of MSI handling are the
> result of a long discussion that took place here[1]. I took the
> liberty to rejig Thomas' initial patches, and add what I needed for
> the MSI domain stuff. Again, blame me if something is wrong, and not
> Thomas.
>
> Feedback welcome.
>
> M.
>
> [1] https://lore.kernel.org/r/20201031140330.83768-1-linux@fw-web.de
>
> Marc Zyngier (11):
> PCI: tegra: Convert to MSI domains
> PCI: rcar: Convert to MSI domains
> PCI: xilinx: Convert to MSI domains
> PCI: hyperv: Drop msi_controller structure
> PCI: MSI: Drop use of msi_controller from core code
> PCI: MSI: Kill msi_controller structure
> PCI: MSI: Kill default_teardown_msi_irqs()
> PCI: MSI: Let PCI host bridges declare their reliance on MSI domains
> PCI: Make pci_host_common_probe() declare its reliance on MSI domains
> PCI: MSI: Document the various ways of ending up with NO_MSI
> PCI: quirks: Refactor advertising of the NO_MSI flag
>
> Thomas Gleixner (2):
> PCI: MSI: Let PCI host bridges declare their lack of MSI handling
> PCI: mediatek: Advertise lack of MSI handling

All looks good to me; I'm guessing Lorenzo will want to apply it or at
least take a look since the bulk of this is in the native host
drivers.

s|PCI: MSI:|PCI/MSI:| above (I use "PCI/<FEATURE>:" and "PCI: <driver>:")
s|PCI: hyperv:|PCI: hv:| to match previous practice

Maybe:

PCI: Refactor HT advertising of NO_MSI flag

since "HT" contains more information than "quirks"?

In the 03/13 commit log, s/appaling/appalling/ :)
In the patch, it sounds like the MSI capture address change might be
separable into its own patch? If it were separate, it would be easier
to see the problem/fix and watch for it elsewhere.

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> drivers/pci/controller/Kconfig | 4 +-
> drivers/pci/controller/pci-host-common.c | 1 +
> drivers/pci/controller/pci-hyperv.c | 4 -
> drivers/pci/controller/pci-tegra.c | 343 ++++++++++++-----------
> drivers/pci/controller/pcie-mediatek.c | 4 +
> drivers/pci/controller/pcie-rcar-host.c | 342 +++++++++++-----------
> drivers/pci/controller/pcie-xilinx.c | 238 +++++++---------
> drivers/pci/msi.c | 46 +--
> drivers/pci/probe.c | 4 +-
> drivers/pci/quirks.c | 15 +-
> include/linux/msi.h | 17 +-
> include/linux/pci.h | 4 +-
> 12 files changed, 463 insertions(+), 559 deletions(-)
>
> --
> 2.29.2
>