[PATCH v4 04/09] iommu/ipmmu-vmsa: Make use of IOMMU_OF_DECLARE()

[Magnus Damm <magnus.damm@gmail.com>]

From: Magnus Damm <damm+renesas@opensource.se>

Hook up IOMMU_OF_DECLARE() support in case CONFIG_IOMMU_DMA
is enabled. The only current supported case for 32-bit ARM
is disabled, however for 64-bit ARM usage of OF is required.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 Changes since V3:
 - Reworked to fit on top of
   [PATCH 00/04] iommu/ipmmu-vmsa: 32-bit ARM update

 Changes since V2:
 - Reworked registration code to make use of recently introduced:
     iommu_device_register()
     iommu_device_set_ops()
     iommu_device_set_fwnode()

 Changes since V1:
 - Reworked slightly to fit updated patch order and
   [PATCH v3 00/06] iommu/ipmmu-vmsa: IPMMU multi-arch update V3

 drivers/iommu/ipmmu-vmsa.c |   43 +++++++++++++++++++++++++++++++++++++------
 1 file changed, 37 insertions(+), 6 deletions(-)

--- 0019/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c	2017-06-19 14:03:53.140607110 +0900
@@ -20,6 +20,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/of_iommu.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/sizes.h>
@@ -1055,13 +1056,25 @@ static int ipmmu_probe(struct platform_d
 		ipmmu_device_reset(mmu);
 	}
 
-	ret = iommu_device_register(&mmu->iommu);
-	if (ret)
-		return ret;
-
-	iommu_device_set_ops(&mmu->iommu, &ipmmu_ops);
-	iommu_device_set_fwnode(&mmu->iommu, &pdev->dev.of_node->fwnode);
+	/*
+	 * Register the IPMMU to the IOMMU subsystem in the following cases:
+	 * - R-Car Gen2 IPMMU (all devices registered)
+	 * - R-Car Gen3 IPMMU (leaf devices only - skip root IPMMU-MM device)
+	 */
+	if (!mmu->features->has_cache_leaf_nodes || mmu->is_leaf) {
+		ret = iommu_device_register(&mmu->iommu);
+		if (ret)
+			return ret;
 
+		iommu_device_set_ops(&mmu->iommu, &ipmmu_ops);
+		iommu_device_set_fwnode(&mmu->iommu,
+					&pdev->dev.of_node->fwnode);
+
+#if defined(CONFIG_IOMMU_DMA)
+		if (!iommu_present(&platform_bus_type))
+			bus_set_iommu(&platform_bus_type, &ipmmu_ops);
+#endif
+	}
 	/*
 	 * We can't create the ARM mapping here as it requires the bus to have
 	 * an IOMMU, which only happens when bus_set_iommu() is called in
@@ -1107,15 +1120,22 @@ static struct platform_driver ipmmu_driv
 
 static int __init ipmmu_init(void)
 {
+	static bool setup_done;
 	int ret;
 
+	if (setup_done)
+		return 0;
+
 	ret = platform_driver_register(&ipmmu_driver);
 	if (ret < 0)
 		return ret;
 
+#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
 	if (!iommu_present(&platform_bus_type))
 		bus_set_iommu(&platform_bus_type, &ipmmu_ops);
+#endif
 
+	setup_done = true;
 	return 0;
 }
 
@@ -1127,6 +1147,17 @@ static void __exit ipmmu_exit(void)
 subsys_initcall(ipmmu_init);
 module_exit(ipmmu_exit);
 
+#ifdef CONFIG_IOMMU_DMA
+static int __init ipmmu_vmsa_iommu_of_setup(struct device_node *np)
+{
+	ipmmu_init();
+	return 0;
+}
+
+IOMMU_OF_DECLARE(ipmmu_vmsa_iommu_of, "renesas,ipmmu-vmsa",
+		 ipmmu_vmsa_iommu_of_setup);
+#endif
+
 MODULE_DESCRIPTION("IOMMU API for Renesas VMSA-compatible IPMMU");
 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 MODULE_LICENSE("GPL v2");