[RFC 08/13] ACPI/IORT: Add callback to update a device's fwnode

[Jean-Philippe Brucker <jean-philippe@linaro.org>]

For a PCI-based IOMMU, IORT isn't in charge of allocating a fwnode. Let
the IOMMU driver update the fwnode associated to an IORT node when
available.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
 drivers/acpi/iort.c       | 38 ++++++++++++++++++++++++++++++++++++++
 include/linux/acpi_iort.h |  4 ++++
 2 files changed, 42 insertions(+)

diff --git a/drivers/acpi/iort.c b/drivers/acpi/iort.c
index f08f72d8af78..8263ab275b2b 100644
--- a/drivers/acpi/iort.c
+++ b/drivers/acpi/iort.c
@@ -1038,11 +1038,49 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
 
 	return ops;
 }
+
+/**
+ * iort_iommu_update_fwnode - update fwnode of a PCI IOMMU
+ * @dev: the IOMMU device
+ * @fwnode: the fwnode, or NULL to remove an existing fwnode
+ *
+ * A PCI device isn't instantiated by the IORT driver. The IOMMU driver sets or
+ * removes its fwnode using this function.
+ */
+void iort_iommu_update_fwnode(struct device *dev, struct fwnode_handle *fwnode)
+{
+	struct pci_dev *pdev;
+	struct iort_fwnode *curr;
+	struct iort_pci_devid *devid;
+
+	if (!dev_is_pci(dev))
+		return;
+
+	pdev = to_pci_dev(dev);
+
+	spin_lock(&iort_fwnode_lock);
+	list_for_each_entry(curr, &iort_fwnode_list, list) {
+		devid = curr->pci_devid;
+		if (devid &&
+		    pci_domain_nr(pdev->bus) == devid->segment &&
+		    pdev->bus->number == devid->bus &&
+		    pdev->devfn == devid->devfn) {
+			WARN_ON(fwnode && curr->fwnode);
+			curr->fwnode = fwnode;
+			break;
+		}
+	}
+	spin_unlock(&iort_fwnode_lock);
+}
+EXPORT_SYMBOL_GPL(iort_iommu_update_fwnode);
 #else
 int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
 { return 0; }
 const struct iommu_ops *iort_iommu_configure(struct device *dev)
 { return NULL; }
+static void iort_iommu_update_fwnode(struct device *dev,
+				     struct fwnode_handle *fwnode)
+{ }
 #endif
 
 static int nc_dma_get_range(struct device *dev, u64 *size)
diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
index f4db5fff07cf..840635e40d9d 100644
--- a/include/linux/acpi_iort.h
+++ b/include/linux/acpi_iort.h
@@ -43,6 +43,7 @@ int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id);
 void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *size);
 const struct iommu_ops *iort_iommu_configure(struct device *dev);
 int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head);
+void iort_iommu_update_fwnode(struct device *dev, struct fwnode_handle *fwnode);
 #else
 static void acpi_iort_register_table(struct acpi_table_header *table,
 				     enum iort_table_source source)
@@ -63,6 +64,9 @@ static inline const struct iommu_ops *iort_iommu_configure(
 static inline
 int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
 { return 0; }
+static void iort_iommu_update_fwnode(struct device *dev,
+				     struct fwnode_handle *fwnode)
+{ }
 #endif
 
 #endif /* __ACPI_IORT_H__ */
-- 
2.24.0