Re: [PATCH v3 0/2] msi: extend msi_irqs sysfs entries to platform devices

Marc Zyngier
2021-08-14T09:45:31Z

On Fri, 13 Aug 2021 04:56:26 +0100,
Barry Song <21cnbao@gmail.com> wrote:
>
> From: Barry Song <song.bao.hua@hisilicon.com>
>
> -v3:
> added Acked-by of Greg Kroah-Hartman and Bjorn Helgaas, thanks!
> refined commit log with respect to Bjorn's comments
>
> Hi Thomas & Marc,
> Would you please handle this series? Thanks!
>
> -v2:
> extract common code for msi_irqs sysfs populate/destory from PCI to MSI core,
> platform_device can directly reuse common code;
> https://lore.kernel.org/lkml/20210812105341.51657-1-21cnbao@gmail.com/
>
> -v1:
> https://lore.kernel.org/lkml/20210811105020.12980-1-song.bao.hua@hisilicon.com/
>
> Just like pci devices have msi_irqs which can be used by userspace irq affinity
> tools or applications to bind irqs, platform devices also widely support msi
> irqs.
> For platform devices, for example ARM SMMU, userspaces also care about its msi
> irqs as applications can know the mapping between devices and irqs and then
> make smarter decision on handling irq affinity. For example, for SVA mode,
> it is better to pin io page fault to the numa node applications are running
> on. Otherwise, io page fault will get a remote page from the node iopf happens
> rather than from the node applications are running on.
>
> The first patch extracts the sysfs populate/destory code from PCI to
> MSI core. The 2nd patch lets platform-msi export msi_irqs entry so that
> userspace can know the mapping between devices and irqs for platform
> devices.

Although I'm not in a position to test it right now, this looks
reasonable to me:

Acked-by: Marc Zyngier <maz@kernel.org>

Thomas, do you want to queue this one, given that you already carry a
ton of MSI-related patches?

Thanks,

M.

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