[PATCH v2 2/3] of: factor arguments passed to of_map_id() into a struct

[Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>]

From: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>

Introduce a new struct type where the optional arguments passed to
of_map_id() are in struct. Subsequent patches add additional arguments
to the struct that the caller expects to be filled of_map_id().

Signed-off-by: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
Signed-off-by: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
---
 drivers/iommu/of_iommu.c              |  6 +++++-
 drivers/of/base.c                     | 31 ++++++++++++++-------------
 drivers/pci/controller/dwc/pci-imx6.c |  6 +++++-
 drivers/pci/controller/pcie-apple.c   |  5 ++++-
 drivers/xen/grant-dma-ops.c           |  5 ++++-
 include/linux/of.h                    | 23 ++++++++++++++------
 6 files changed, 50 insertions(+), 26 deletions(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index a511ecf21fcd..eac62bc441c5 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -46,9 +46,13 @@ static int of_iommu_configure_dev_id(struct device_node *master_np,
 				     const u32 *id)
 {
 	struct of_phandle_args iommu_spec = { .args_count = 1 };
+	struct of_map_id_arg arg = {
+		.target = &iommu_spec.np,
+		.id_out = iommu_spec.args,
+	};
 	int err;
 
-	err = of_map_iommu_id(master_np, *id, &iommu_spec.np, iommu_spec.args);
+	err = of_map_iommu_id(master_np, *id, &arg);
 	if (err)
 		return err;
 
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 7043acd971a0..b8f78a9e6a09 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2051,8 +2051,9 @@ 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: contains the optional params, @target which is a pointer
+ *	to the target device node and id_out which is a pointer
+ *	to receive the translated ID.
  *
  * Given a device ID, look up the appropriate implementation-defined
  * platform ID and/or the target device which receives transactions on that
@@ -2066,21 +2067,21 @@ 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_map_id_arg *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 || (!arg->target && !arg->id_out))
 		return -EINVAL;
 
 	map = of_get_property(np, map_name, &map_len);
 	if (!map) {
-		if (target)
+		if (arg->target)
 			return -ENODEV;
 		/* Otherwise, no map implies no translation */
-		*id_out = id;
+		*arg->id_out = id;
 		return 0;
 	}
 
@@ -2122,18 +2123,18 @@ int of_map_id(const struct device_node *np, u32 id,
 		if (!phandle_node)
 			return -ENODEV;
 
-		if (target) {
-			if (*target)
+		if (arg->target) {
+			if (*arg->target)
 				of_node_put(phandle_node);
 			else
-				*target = phandle_node;
+				*arg->target = phandle_node;
 
-			if (*target != phandle_node)
+			if (*arg->target != phandle_node)
 				continue;
 		}
 
-		if (id_out)
-			*id_out = masked_id - id_base + out_base;
+		if (arg->id_out)
+			*arg->id_out = 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,
@@ -2142,11 +2143,11 @@ 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->target && *arg->target ? *arg->target : NULL);
 
 	/* Bypasses translation */
-	if (id_out)
-		*id_out = id;
+	if (arg->id_out)
+		*arg->id_out = 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 c8da2e88e9c6..7b54295e553b 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1101,12 +1101,16 @@ 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_map_id_arg arg = {};
 	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);
+
+	arg.target = &target;
+	arg.id_out = &sid_i;
+	err_i = of_map_iommu_id(dev->of_node, rid, &arg);
 	if (target) {
 		of_node_put(target);
 	} else {
diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c
index ce21728d6e51..965f65ce8ad3 100644
--- a/drivers/pci/controller/pcie-apple.c
+++ b/drivers/pci/controller/pcie-apple.c
@@ -782,6 +782,7 @@ 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_map_id_arg arg = {};
 	int idx, err;
 
 	port = apple_pcie_get_port(pdev);
@@ -791,7 +792,9 @@ 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);
+	arg.target = NULL;
+	arg.id_out = &sid;
+	err = of_map_iommu_id(port->pcie->dev->of_node, rid, &arg);
 	if (err)
 		return err;
 
diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c
index b661f9c1f4fe..179f6f43a57b 100644
--- a/drivers/xen/grant-dma-ops.c
+++ b/drivers/xen/grant-dma-ops.c
@@ -319,9 +319,12 @@ static int xen_dt_grant_init_backend_domid(struct device *dev,
 
 	if (dev_is_pci(dev)) {
 		struct pci_dev *pdev = to_pci_dev(dev);
+		struct of_map_id_arg arg = {};
 		u32 rid = PCI_DEVID(pdev->bus->number, pdev->devfn);
 
-		if (of_map_iommu_id(np, rid, &iommu_spec.np, iommu_spec.args)) {
+		arg.target = &iommu_spec.np;
+		arg.id_out = iommu_spec.args;
+		if (of_map_iommu_id(np, rid, &arg)) {
 			dev_dbg(dev, "Cannot translate ID\n");
 			return -ESRCH;
 		}
diff --git a/include/linux/of.h b/include/linux/of.h
index 8cd486d89da2..21bdce2b37ca 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -25,6 +25,12 @@
 typedef u32 phandle;
 typedef u32 ihandle;
 
+struct device_node;
+struct of_map_id_arg {
+	struct device_node **target;
+	u32 *id_out;
+};
+
 struct property {
 	char	*name;
 	int	length;
@@ -458,7 +464,7 @@ 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_map_id_arg *arg);
 
 phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
 
@@ -907,7 +913,7 @@ 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_map_id_arg *arg)
 {
 	return -EINVAL;
 }
@@ -1436,17 +1442,20 @@ 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_map_id_arg *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_map_id_arg arg = {
+		.target = target,
+		.id_out = id_out,
+	};
+
+	return of_map_id(np, id, "msi-map", "msi-map-mask", &arg);
 }
 
 #define of_for_each_phandle(it, err, np, ln, cn, cc)			\
-- 
2.34.1