Re: [patch 24/33] PCI/MSI: Provide prepare_desc() MSI domain op

From: Jason Gunthorpe
Date: Wed Nov 16 2022 - 14:41:01 EST


On Fri, Nov 11, 2022 at 02:58:49PM +0100, Thomas Gleixner wrote:
> Dynamic MSI-X vector allocation post MSI-X allows to allocate vectors at a
> given index or at any free index in the available table range. The latter
> requires that the core code selects the index at descriptor allocation time.
>
> This requires that the PCI/MSI-X specific setup of the MSI-X descriptor,
> which is partially depending on the chosen index happens after allocation.
>
> Implement the prepare_desc() op in the PCI/MSI-X specific msi_domain_ops
> which is invoked before the core interrupt descriptor and the associated
> Linux interrupt number is allocated. That callback is also provided for the
> upcoming PCI/IMS implementations so the implementation specific interrupt
> domain can do their domain specific initialization of the MSI descriptors.
>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
> drivers/pci/msi/irqdomain.c | 9 +++++++++
> 1 file changed, 9 insertions(+)

Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>

Jason