irqchip/gic-v5: Add ACPI ITS probing

On ACPI ARM64 systems the GICv5 ITS configuration and translate frames
are described in the MADT table.

Refactor the current GICv5 ITS driver code to share common functions
between ACPI and OF and implement ACPI probing in the GICv5 ITS driver.

Add iort_msi_xlate() to map a device ID and retrieve an MSI controller
fwnode node for ACPI systems and update pci_msi_map_rid_ctlr_node() to
use it in its ACPI code path.

Add the required functions to IORT code for deviceID retrieval and IRQ
domain registration and look-up so that the GICv5 ITS driver in an
ACPI based system can be successfully probed.

Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Acked-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260115-gicv5-host-acpi-v3-5-c13a9a150388@kernel.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 77 insertions, 21 deletions

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 65f0f56ad753..ddd857f05f46 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -595,45 +595,45 @@ u32 iort_msi_map_id(struct device *dev, u32 input_id)
 }
 
 /**
- * iort_pmsi_get_dev_id() - Get the device id for a device
+ * iort_msi_xlate() - Map a MSI input ID for a device
  * @dev: The device for which the mapping is to be done.
- * @dev_id: The device ID found.
+ * @input_id: The device input ID.
+ * @fwnode: Pointer to store the fwnode.
  *
- * Returns: 0 for successful find a dev id, -ENODEV on error
+ * Returns: mapped MSI ID on success, input ID otherwise
+ *	    On success, the fwnode pointer is initialized to the MSI
+ *	    controller fwnode handle.
  */
-int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
+u32 iort_msi_xlate(struct device *dev, u32 input_id, struct fwnode_handle **fwnode)
 {
-	int i, index;
+	struct acpi_iort_its_group *its;
 	struct acpi_iort_node *node;
+	u32 dev_id;
 
 	node = iort_find_dev_node(dev);
 	if (!node)
-		return -ENODEV;
+		return input_id;
 
-	index = iort_get_id_mapping_index(node);
-	/* if there is a valid index, go get the dev_id directly */
-	if (index >= 0) {
-		if (iort_node_get_id(node, dev_id, index))
-			return 0;
-	} else {
-		for (i = 0; i < node->mapping_count; i++) {
-			if (iort_node_map_platform_id(node, dev_id,
-						      IORT_MSI_TYPE, i))
-				return 0;
-		}
-	}
+	node = iort_node_map_id(node, input_id, &dev_id, IORT_MSI_TYPE);
+	if (!node)
+		return input_id;
 
-	return -ENODEV;
+	/* Move to ITS specific data */
+	its = (struct acpi_iort_its_group *)node->node_data;
+
+	*fwnode = iort_find_domain_token(its->identifiers[0]);
+
+	return dev_id;
 }
 
-static int __maybe_unused iort_find_its_base(u32 its_id, phys_addr_t *base)
+int iort_its_translate_pa(struct fwnode_handle *node, phys_addr_t *base)
 {
 	struct iort_its_msi_chip *its_msi_chip;
 	int ret = -ENODEV;
 
 	spin_lock(&iort_msi_chip_lock);
 	list_for_each_entry(its_msi_chip, &iort_msi_chip_list, list) {
-		if (its_msi_chip->translation_id == its_id) {
+		if (its_msi_chip->fw_node == node) {
 			*base = its_msi_chip->base_addr;
 			ret = 0;
 			break;
@@ -644,6 +644,62 @@ static int __maybe_unused iort_find_its_base(u32 its_id, phys_addr_t *base)
 	return ret;
 }
 
+static int __maybe_unused iort_find_its_base(u32 its_id, phys_addr_t *base)
+{
+	struct fwnode_handle *fwnode = iort_find_domain_token(its_id);
+
+	if (!fwnode)
+		return -ENODEV;
+
+	return iort_its_translate_pa(fwnode, base);
+}
+
+/**
+ * iort_pmsi_get_msi_info() - Get the device id and translate frame PA for a device
+ * @dev: The device for which the mapping is to be done.
+ * @dev_id: The device ID found.
+ * @pa: optional pointer to store translate frame address.
+ *
+ * Returns: 0 for successful devid and pa retrieval, -ENODEV on error
+ */
+int iort_pmsi_get_msi_info(struct device *dev, u32 *dev_id, phys_addr_t *pa)
+{
+	struct acpi_iort_node *node, *parent = NULL;
+	struct acpi_iort_its_group *its;
+	int i, index;
+
+	node = iort_find_dev_node(dev);
+	if (!node)
+		return -ENODEV;
+
+	index = iort_get_id_mapping_index(node);
+	/* if there is a valid index, go get the dev_id directly */
+	if (index >= 0) {
+		parent = iort_node_get_id(node, dev_id, index);
+	} else {
+		for (i = 0; i < node->mapping_count; i++) {
+			parent = iort_node_map_platform_id(node, dev_id,
+						      IORT_MSI_TYPE, i);
+			if (parent)
+				break;
+		}
+	}
+
+	if (!parent)
+		return -ENODEV;
+
+	if (pa) {
+		int ret;
+
+		its = (struct acpi_iort_its_group *)node->node_data;
+		ret = iort_find_its_base(its->identifiers[0], pa);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 /**
  * iort_dev_find_its_id() - Find the ITS identifier for a device
  * @dev: The device.