Re: [patch V3 28/33] PCI/MSI: Provide IMS (Interrupt Message Store) support

[Bjorn Helgaas]

On Fri, Nov 25, 2022 at 12:26:29AM +0100, Thomas Gleixner wrote:
> IMS (Interrupt Message Store) is a new specification which allows
> implementation specific storage of MSI messages contrary to the
> strict standard specified MSI and MSI-X message stores.
> ...

> + * pci_create_ims_domain - Create a secondary IMS domain for a PCI device

> + * Return: True on success, false otherwise

> +bool pci_create_ims_domain(struct pci_dev *pdev, const struct msi_domain_template *template,
> +			   unsigned int hwsize, void *data)

pci_create_ims_domain() is exported for use by modules, but AFAICT,
there is no in-tree user of this yet.

I assume one is coming, but if there isn't one on the near horizon,
we could/should remove this for now.

Either way, I think "bool" is not the optimal return type because
"pci_create_ims_domain" doesn't lend itself to a "true/false" reading
and most interfaces that actually do something return 0 for success or
a negative errno, so this will look like the opposite in the caller.

I have similar comments about the following interfaces returning
"bool", but they are internal to the PCI core:

  bool pci_create_device_domain()
  bool pci_setup_msi_device_domain()
  bool pci_setup_msix_device_domain()

Bjorn