[PATCH v9 2/3] of: factor arguments passed to of_map_id() into a struct

[Vijayanand Jitta <vijayanand.jitta@xxxxxxxxxxxxxxxx>]

From: Charan Teja Kalla <charan.kalla@xxxxxxxxxxxxxxxx>

Change of_map_id() to take a pointer to struct of_phandle_args
instead of passing target device node and translated IDs separately.
Update all callers accordingly.

Subsequent patch will make use of the args_count field in
struct of_phandle_args.

Suggested-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
Signed-off-by: Charan Teja Kalla <charan.kalla@xxxxxxxxxxxxxxxx>
Signed-off-by: Vijayanand Jitta <vijayanand.jitta@xxxxxxxxxxxxxxxx>
---
 drivers/iommu/of_iommu.c              |  2 +-
 drivers/of/base.c                     | 37 +++++++++++++++++------------------
 drivers/pci/controller/dwc/pci-imx6.c |  8 +++++++-
 drivers/pci/controller/pcie-apple.c   |  4 +++-
 drivers/xen/grant-dma-ops.c           |  2 +-
 include/linux/of.h                    | 21 +++++++++++++-------
 6 files changed, 44 insertions(+), 30 deletions(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index a511ecf21fcd..d255d0f58e8c 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -48,7 +48,7 @@ static int of_iommu_configure_dev_id(struct device_node 
*master_np,
        struct of_phandle_args iommu_spec = { .args_count = 1 };
        int err;
 
-       err = of_map_iommu_id(master_np, *id, &iommu_spec.np, iommu_spec.args);
+       err = of_map_iommu_id(master_np, *id, &iommu_spec);
        if (err)
                return err;
 
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 57420806c1a2..6c3628255908 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2102,8 +2102,11 @@ int of_find_last_cache_level(unsigned int cpu)
  * @id: device ID to map.
  * @map_name: property name of the map to use.
  * @map_mask_name: optional property name of the mask to use.
- * @target: optional pointer to a target device node.
- * @id_out: optional pointer to receive the translated ID.
+ * @arg: of_phandle_args structure,
+ *     which includes:
+ *     np: pointer to the target device node
+ *     args_count: number of arguments
+ *     args[]: array to receive the translated ID(s).
  *
  * Given a device ID, look up the appropriate implementation-defined
  * platform ID and/or the target device which receives transactions on that
@@ -2117,21 +2120,21 @@ int of_find_last_cache_level(unsigned int cpu)
  */
 int of_map_id(const struct device_node *np, u32 id,
               const char *map_name, const char *map_mask_name,
-              struct device_node **target, u32 *id_out)
+              struct of_phandle_args *arg)
 {
        u32 map_mask, masked_id;
        int map_len;
        const __be32 *map = NULL;
 
-       if (!np || !map_name || (!target && !id_out))
+       if (!np || !map_name || !arg)
                return -EINVAL;
 
        map = of_get_property(np, map_name, &map_len);
        if (!map) {
-               if (target)
+               if (arg->np)
                        return -ENODEV;
                /* Otherwise, no map implies no translation */
-               *id_out = id;
+               arg->args[0] = id;
                return 0;
        }
 
@@ -2173,18 +2176,15 @@ int of_map_id(const struct device_node *np, u32 id,
                if (!phandle_node)
                        return -ENODEV;
 
-               if (target) {
-                       if (*target)
-                               of_node_put(phandle_node);
-                       else
-                               *target = phandle_node;
+               if (arg->np)
+                       of_node_put(phandle_node);
+               else
+                       arg->np = phandle_node;
 
-                       if (*target != phandle_node)
-                               continue;
-               }
+               if (arg->np != phandle_node)
+                       continue;
 
-               if (id_out)
-                       *id_out = masked_id - id_base + out_base;
+               arg->args[0] = masked_id - id_base + out_base;
 
                pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: 
%08x, length: %08x, id: %08x -> %08x\n",
                        np, map_name, map_mask, id_base, out_base,
@@ -2193,11 +2193,10 @@ int of_map_id(const struct device_node *np, u32 id,
        }
 
        pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
-               id, target && *target ? *target : NULL);
+               id, arg->np ? arg->np : NULL);
 
        /* Bypasses translation */
-       if (id_out)
-               *id_out = id;
+       arg->args[0] = id;
        return 0;
 }
 EXPORT_SYMBOL_GPL(of_map_id);
diff --git a/drivers/pci/controller/dwc/pci-imx6.c 
b/drivers/pci/controller/dwc/pci-imx6.c
index bff8289f804a..74fc603b3f84 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1139,12 +1139,18 @@ static int imx_pcie_add_lut_by_rid(struct imx_pcie 
*imx_pcie, u32 rid)
 {
        struct device *dev = imx_pcie->pci->dev;
        struct device_node *target;
+       struct of_phandle_args iommu_spec = { .args_count = 1 };
        u32 sid_i, sid_m;
        int err_i, err_m;
        u32 sid = 0;
 
        target = NULL;
-       err_i = of_map_iommu_id(dev->of_node, rid, &target, &sid_i);
+       err_i = of_map_iommu_id(dev->of_node, rid, &iommu_spec);
+       if (!err_i) {
+               target = iommu_spec.np;
+               sid_i = iommu_spec.args[0];
+       }
+
        if (target) {
                of_node_put(target);
        } else {
diff --git a/drivers/pci/controller/pcie-apple.c 
b/drivers/pci/controller/pcie-apple.c
index a0937b7b3c4d..e1d4b37d200d 100644
--- a/drivers/pci/controller/pcie-apple.c
+++ b/drivers/pci/controller/pcie-apple.c
@@ -755,6 +755,7 @@ static int apple_pcie_enable_device(struct pci_host_bridge 
*bridge, struct pci_d
 {
        u32 sid, rid = pci_dev_id(pdev);
        struct apple_pcie_port *port;
+       struct of_phandle_args iommu_spec = { .args_count = 1 };
        int idx, err;
 
        port = apple_pcie_get_port(pdev);
@@ -764,10 +765,11 @@ static int apple_pcie_enable_device(struct 
pci_host_bridge *bridge, struct pci_d
        dev_dbg(&pdev->dev, "added to bus %s, index %d\n",
                pci_name(pdev->bus->self), port->idx);
 
-       err = of_map_iommu_id(port->pcie->dev->of_node, rid, NULL, &sid);
+       err = of_map_iommu_id(port->pcie->dev->of_node, rid, &iommu_spec);
        if (err)
                return err;
 
+       sid = iommu_spec.args[0];
        mutex_lock(&port->pcie->lock);
 
        idx = bitmap_find_free_region(port->sid_map, port->sid_map_sz, 0);
diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c
index 1b7696b2d762..5f1d6540049a 100644
--- a/drivers/xen/grant-dma-ops.c
+++ b/drivers/xen/grant-dma-ops.c
@@ -325,7 +325,7 @@ static int xen_dt_grant_init_backend_domid(struct device 
*dev,
                struct pci_dev *pdev = to_pci_dev(dev);
                u32 rid = PCI_DEVID(pdev->bus->number, pdev->devfn);
 
-               if (of_map_iommu_id(np, rid, &iommu_spec.np, iommu_spec.args)) {
+               if (of_map_iommu_id(np, rid, &iommu_spec)) {
                        dev_dbg(dev, "Cannot translate ID\n");
                        return -ESRCH;
                }
diff --git a/include/linux/of.h b/include/linux/of.h
index 824649867810..9d72d76f909d 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -463,7 +463,7 @@ bool of_console_check(const struct device_node *dn, char 
*name, int index);
 
 int of_map_id(const struct device_node *np, u32 id,
               const char *map_name, const char *map_mask_name,
-              struct device_node **target, u32 *id_out);
+              struct of_phandle_args *arg);
 
 phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
 
@@ -929,7 +929,7 @@ static inline void of_property_clear_flag(struct property 
*p, unsigned long flag
 
 static inline int of_map_id(const struct device_node *np, u32 id,
                             const char *map_name, const char *map_mask_name,
-                            struct device_node **target, u32 *id_out)
+                            struct of_phandle_args *arg)
 {
        return -EINVAL;
 }
@@ -1458,17 +1458,24 @@ static inline int of_property_read_s32(const struct 
device_node *np,
 }
 
 static inline int of_map_iommu_id(const struct device_node *np, u32 id,
-                                 struct device_node **target, u32 *id_out)
+                                 struct of_phandle_args *arg)
 {
-       return of_map_id(np, id, "iommu-map", "iommu-map-mask",
-                        target, id_out);
+       return of_map_id(np, id, "iommu-map", "iommu-map-mask", arg);
 }
 
 static inline int of_map_msi_id(const struct device_node *np, u32 id,
                                struct device_node **target, u32 *id_out)
 {
-       return of_map_id(np, id, "msi-map", "msi-map-mask",
-                        target, id_out);
+       struct of_phandle_args msi_spec = { .np = *target, .args_count = 1 };
+       int ret;
+
+       ret = of_map_id(np, id, "msi-map", "msi-map-mask", &msi_spec);
+       if (!ret) {
+               *target = msi_spec.np;
+               *id_out = msi_spec.args[0];
+       }
+
+       return ret;
 }
 
 #define of_for_each_phandle(it, err, np, ln, cn, cc)                   \

-- 
2.34.1