IRQchip drivers need a PCI/MSI function to map a RID to a MSI
controller deviceID namespace and at the same time retrieve the
struct device_node pointer of the MSI controller the RID is mapped
to.
Add pci_msi_map_rid_ctlr_node() to achieve this purpose.
Signed-off-by: Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx>
Reviewed-by: Marc Zyngier <maz@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
---
drivers/pci/msi/irqdomain.c | 20 ++++++++++++++++++++
include/linux/msi.h | 1 +
2 files changed, 21 insertions(+)
diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
index c05152733993..8a6e80d3963a 100644
--- a/drivers/pci/msi/irqdomain.c
+++ b/drivers/pci/msi/irqdomain.c
@@ -427,6 +427,26 @@ u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
return rid;
}
+/**
+ * pci_msi_map_rid_ctlr_node - Get the MSI controller node and MSI requester id (RID)
+ * @pdev: The PCI device
+ * @node: Pointer to store the MSI controller device node
+ *
+ * Use the firmware data to find the MSI controller node for @pdev.
+ * If found map the RID and initialize @node with it. @node value must
+ * be set to NULL on entry.
+ *
+ * Returns: The RID.
+ */
+u32 pci_msi_map_rid_ctlr_node(struct pci_dev *pdev, struct device_node **node)
+{
+ u32 rid = pci_dev_id(pdev);
+
+ pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
+
+ return of_msi_xlate(&pdev->dev, node, rid);
+}
+
/**
* pci_msi_get_device_domain - Get the MSI domain for a given PCI device
* @pdev: The PCI device
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 6863540f4b71..a418e2695b05 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -705,6 +705,7 @@ struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
struct msi_domain_info *info,
struct irq_domain *parent);
u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev);
+u32 pci_msi_map_rid_ctlr_node(struct pci_dev *pdev, struct device_node **node);
struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev);
#else /* CONFIG_PCI_MSI */
static inline struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
--
2.48.0
