Re: [PATCH V3 2/6] acpi: pci: Setup MSI domain for ACPI based pci devices

[Marc Zyngier <marc.zyngier@arm.com>]

On Wed, 21 Oct 2015 11:47:25 -0700
Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> wrote:

Hi Suravee,

Sorry it took so long to get to this series. Comments below.

> This patch introduces pci_host_bridge_acpi_msi_domain(), which returns
> the MSI domain of the specified PCI host bridge with DOMAIN_BUS_PCI_MSI
> bus token. Then, it is assigned to pci device.
> 
> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> ---
>  drivers/pci/pci-acpi.c | 13 +++++++++++++
>  drivers/pci/probe.c    |  2 ++
>  include/linux/pci.h    |  7 +++++++
>  3 files changed, 22 insertions(+)
> 
> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> index a32ba75..0e21ef4 100644
> --- a/drivers/pci/pci-acpi.c
> +++ b/drivers/pci/pci-acpi.c
> @@ -9,7 +9,9 @@
>  
>  #include <linux/delay.h>
>  #include <linux/init.h>
> +#include <linux/irqdomain.h>
>  #include <linux/pci.h>
> +#include <linux/msi.h>
>  #include <linux/pci_hotplug.h>
>  #include <linux/module.h>
>  #include <linux/pci-aspm.h>
> @@ -689,6 +691,17 @@ static struct acpi_bus_type acpi_pci_bus = {
>  	.cleanup = pci_acpi_cleanup,
>  };
>  
> +struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
> +{
> +	struct irq_domain *dom = NULL;
> +	struct fwnode_handle *fwnode = pci_msi_get_fwnode(&bus->dev);
> +
> +	if (fwnode)
> +		dom = irq_find_matching_fwnode(fwnode,
> +					       DOMAIN_BUS_PCI_MSI);
> +	return dom;
> +}
> +

Given this, I really question the need for what you define in patch #1
to be standalone. It is only used by ACPI (DT has its own private
helpers), and it is so far unlikely that it will be of any use for
other firmware interfaces.

My suggestion is to get rid of pci_msi_get_fwnode() and move the
registration helper into this file. That'd be much simpler.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny.