Re: [PATCH v2 0/2] msi: extend msi_irqs sysfs entries to platform devices

[Bjorn Helgaas]

On Thu, Aug 12, 2021 at 10:53:39PM +1200, Barry Song wrote:
> From: Barry Song <song.bao.hua@xxxxxxxxxxxxx>
> 
> 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.
> 
> -v2:
>   extract common code for msi_irqs sysfs populate/destory from PCI to MSI core,
>   platform_device can directly reuse common code;
> 
> -v1:
>   https://lore.kernel.org/lkml/20210811105020.12980-1-song.bao.hua@xxxxxxxxxxxxx/
> 
> Barry Song (2):
>   genirq/msi: extract common sysfs populate entries to msi core from pci
>   platform-msi: Add ABI to show msi_irqs of platform devices
> 
>  Documentation/ABI/testing/sysfs-bus-platform |  14 +++
>  drivers/base/platform-msi.c                  |  10 ++
>  drivers/pci/msi.c                            | 124 ++-----------------------
>  include/linux/msi.h                          |   4 +
>  kernel/irq/msi.c                             | 134 +++++++++++++++++++++++++++
>  5 files changed, 171 insertions(+), 115 deletions(-)

I assume the IRQ guys will take care of this.

For the drivers/pci/ part:

Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>

But I would update the commit logs to consistently capitalize
initialisms.  Currently it's a mix of "PCI", "pci", "MSI", "msi",
"numa", "irq", "io", etc.

Also, if you rewrap the 2/2 commit log to fit in 75 columns, you won't
have a line that becomes 83 columns when "git log" indents it.  Maybe
also indent quoted things like the "ls" output by 2 spaces and add a
blank line before so the text doesn't run into them.