On Tue, Oct 06, 2015 at 06:04:03PM +0100, Marc Zyngier wrote:
> So far, we've always considered that for a given PCI device, its
> MSI controller was either set by the architecture-specific
> pcibios hook, or simply inherited from the host bridge.
>
> This doesn't cover things like firmware-defined topologies like
> msi-map (DT) or IORT (ACPI), which can provide information about
> which MSI controller to use on a per-device basis.
>
> This patch adds the necessary hook into the MSI code to allow this
> feature, and provides the msi-map functionnality as a first
> implementation.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
I assume somebody other than me will merge this series.
> ---
> drivers/pci/msi.c | 17 +++++++++++++++++
> drivers/pci/probe.c | 8 ++++++++
> include/linux/msi.h | 6 ++++++
> 3 files changed, 31 insertions(+)
>
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index 81a2798..3daff31 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -1357,4 +1357,21 @@ u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
>
> return rid;
> }
> +
> +/**
> + * pci_msi_get_device_domain - Get the MSI domain for a given PCI device
> + * @pdev: The PCI device
> + *
> + * Use the firmware data to find a device-specific MSI domain
> + * (i.e. not one that is ste as a default).
> + *
> + * Returns: The coresponding MSI domain or NULL if none has been found.
> + */
> +struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
> +{
> + u32 rid = 0;
> +
> + pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
> + return of_msi_map_get_device_domain(&pdev->dev, rid);
> +}
> #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 7c333f8..f14a970 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1639,6 +1639,14 @@ static struct irq_domain *pci_dev_msi_domain(struct pci_dev *dev)
> if (d)
> return d;
>
> + /*
> + * Let's see if we have a firmware interface able to provide
> + * the domain.
> + */
> + d = pci_msi_get_device_domain(dev);
> + if (d)
> + return d;
> +
> return NULL;
> }
>
> diff --git a/include/linux/msi.h b/include/linux/msi.h
> index 56e3b76..375be7c 100644
> --- a/include/linux/msi.h
> +++ b/include/linux/msi.h
> @@ -294,6 +294,12 @@ irq_hw_number_t pci_msi_domain_calc_hwirq(struct pci_dev *dev,
> int pci_msi_domain_check_cap(struct irq_domain *domain,
> struct msi_domain_info *info, struct device *dev);
> u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev);
> +struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev);
> +#else
> +static inline struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
> +{
> + return NULL;
> +}
> #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
>
> #endif /* LINUX_MSI_H */
> --
> 2.1.4
>
> --
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