Commit b6eec9b7 authored by David Daney's avatar David Daney Committed by Marc Zyngier
Browse files

PCI/MSI: Add helper function pci_msi_domain_get_msi_rid(). 



Add pci_msi_domain_get_msi_rid() to return the MSI requester id (RID).
Initially needed by gic-v3 based systems. It will be used by follow on
patch to drivers/irqchip/irq-gic-v3-its-pci-msi.c

Initially supports mapping the RID via OF device tree.  In the future,
this could be extended to use ACPI _IORT tables as well.

Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: default avatarDavid Daney <david.daney@cavium.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 8db02d8b

drivers/pci/msi.c

+32 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/io.h>

#include <linux/slab.h>

#include <linux/irqdomain.h>

#include <linux/of_irq.h>



#include "pci.h"
@@ -1327,4 +1328,35 @@ struct irq_domain *pci_msi_create_default_irq_domain(struct fwnode_handle *fwnod 


	return domain;

}



static int get_msi_id_cb(struct pci_dev *pdev, u16 alias, void *data)

{

	u32 *pa = data;



	*pa = alias;

	return 0;

}

/**

 * pci_msi_domain_get_msi_rid - Get the MSI requester id (RID)

 * @domain:	The interrupt domain

 * @pdev:	The PCI device.

 *

 * The RID for a device is formed from the alias, with a firmware

 * supplied mapping applied

 *

 * Returns: The RID.

 */

u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)

{

	struct device_node *of_node;

	u32 rid = 0;



	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);



	of_node = irq_domain_get_of_node(domain);

	if (of_node)

		rid = of_msi_map_rid(&pdev->dev, of_node, rid);



	return rid;

}

#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */

include/linux/msi.h

+1 −0
Original line number Diff line number Diff line
@@ -294,6 +294,7 @@ irq_hw_number_t pci_msi_domain_calc_hwirq(struct pci_dev *dev, 
					  struct msi_desc *desc);

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);

#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */



#endif /* LINUX_MSI_H */

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