irqchip/gic-its: Rework platform MSI deviceID detection

Current code retrieving platform devices MSI devID in the GIC ITS MSI
parent helpers suffers from some minor issues:

- It leaks a struct device_node reference
- It is duplicated between GICv3 and GICv5 for no good reason
- It does not use the OF phandle iterator code that simplifies
  the msi-parent property parsing

Consolidate GIC v3 and v5 deviceID retrieval in a function that addresses
the full set of issues in one go by merging GIC v3 and v5 code and
converting the msi-parent parsing loop to the more modern OF phandle
iterator API, fixing the struct device_node reference leak in the process.

Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://patch.msgid.link/20251021124103.198419-6-lpieralisi@kernel.org

diff --git a/drivers/irqchip/irq-gic-its-msi-parent.c b/drivers/irqchip/irq-gic-its-msi-parent.c
index eb1473f1448acf978323ba4e11f4da61b3901279..12f45228c8674cf12ba74d0089ce9fb3d0b0b012 100644 (file)
--- a/drivers/irqchip/irq-gic-its-msi-parent.c
+++ b/drivers/irqchip/irq-gic-its-msi-parent.c
@@ -142,83 +142,38 @@ static int its_v5_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
 #define its_v5_pci_msi_prepare NULL
 #endif /* !CONFIG_PCI_MSI */
 
-static int of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev,
-                                 u32 *dev_id)
+static int of_pmsi_get_msi_info(struct irq_domain *domain, struct device *dev, u32 *dev_id,
+                               phys_addr_t *pa)
 {
-       int ret, index = 0;
+       struct of_phandle_iterator it;
+       int ret;
 
        /* Suck the DeviceID out of the msi-parent property */
-       do {
-               struct of_phandle_args args;
-
-               ret = of_parse_phandle_with_args(dev->of_node,
-                                                "msi-parent", "#msi-cells",
-                                                index, &args);
-               if (args.np == irq_domain_get_of_node(domain)) {
-                       if (WARN_ON(args.args_count != 1))
-                               return -EINVAL;
-                       *dev_id = args.args[0];
-                       break;
-               }
-               index++;
-       } while (!ret);
-
-       if (ret) {
-               struct device_node *np = NULL;
+       of_for_each_phandle(&it, ret, dev->of_node, "msi-parent", "#msi-cells", -1) {
+               /* GICv5 ITS domain matches the MSI controller node parent */
+               struct device_node *np __free(device_node) = pa ? of_get_parent(it.node)
+                                                               : of_node_get(it.node);
 
-               ret = of_map_id(dev->of_node, dev->id, "msi-map", "msi-map-mask", &np, dev_id);
-               if (np)
-                       of_node_put(np);
-       }
+               if (np == irq_domain_get_of_node(domain)) {
+                       u32 args;
 
-       return ret;
-}
+                       if (WARN_ON(of_phandle_iterator_args(&it, &args, 1) != 1))
+                               ret = -EINVAL;
 
-static int of_v5_pmsi_get_msi_info(struct irq_domain *domain, struct device *dev,
-                                  u32 *dev_id, phys_addr_t *pa)
-{
-       int ret, index = 0;
-       /*
-        * Retrieve the DeviceID and the ITS translate frame node pointer
-        * out of the msi-parent property.
-        */
-       do {
-               struct of_phandle_args args;
-
-               ret = of_parse_phandle_with_args(dev->of_node,
-                                                "msi-parent", "#msi-cells",
-                                                index, &args);
-               if (ret)
-                       break;
-               /*
-                * The IRQ domain fwnode is the msi controller parent
-                * in GICv5 (where the msi controller nodes are the
-                * ITS translate frames).
-                */
-               if (args.np->parent == irq_domain_get_of_node(domain)) {
-                       if (WARN_ON(args.args_count != 1))
-                               return -EINVAL;
-                       *dev_id = args.args[0];
-
-                       ret = its_translate_frame_address(args.np, pa);
-                       if (ret)
-                               return -ENODEV;
-                       break;
-               }
-               index++;
-       } while (!ret);
+                       if (!ret && pa)
+                               ret = its_translate_frame_address(it.node, pa);
 
-       if (ret) {
-               struct device_node *np = NULL;
+                       if (!ret)
+                               *dev_id = args;
 
-               ret = of_map_id(dev->of_node, dev->id, "msi-map", "msi-map-mask", &np, dev_id);
-               if (np) {
-                       ret = its_translate_frame_address(np, pa);
-                       of_node_put(np);
+                       of_node_put(it.node);
+                       return ret;
                }
        }
 
-       return ret;
+       struct device_node *msi_ctrl __free(device_node) = NULL;
+
+       return of_map_id(dev->of_node, dev->id, "msi-map", "msi-map-mask", &msi_ctrl, dev_id);
 }
 
 int __weak iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
@@ -234,7 +189,7 @@ static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
        int ret;
 
        if (dev->of_node)
-               ret = of_pmsi_get_dev_id(domain->parent, dev, &dev_id);
+               ret = of_pmsi_get_msi_info(domain->parent, dev, &dev_id, NULL);
        else
                ret = iort_pmsi_get_dev_id(dev, &dev_id);
        if (ret)
@@ -262,7 +217,7 @@ static int its_v5_pmsi_prepare(struct irq_domain *domain, struct device *dev,
        if (!dev->of_node)
                return -ENODEV;
 
-       ret = of_v5_pmsi_get_msi_info(domain->parent, dev, &dev_id, &pa);
+       ret = of_pmsi_get_msi_info(domain->parent, dev, &dev_id, &pa);
        if (ret)
                return ret;