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Commit 54fa97ee authored by Marc Zyngier's avatar Marc Zyngier
Browse files

PCI/MSI: Allow the MSI domain to be device-specific 



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.

Acked-by: default avatarRob Herring <robh@kernel.org>
Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 098259eb

drivers/pci/msi.c

+17 −0
Original line number Diff line number Diff line
@@ -1359,4 +1359,21 @@ 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 */

drivers/pci/probe.c

+8 −0
Original line number Diff line number Diff line
@@ -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;

}

include/linux/msi.h

+6 −0
Original line number Diff line number Diff line
@@ -295,6 +295,12 @@ 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 */