ARM: tegra: bus_notifier registers platform IOMMU devices

Most of platform devices are IOMMU'able in Tegra30 SoC. Registering
all IOMMU'able devices manually isn't nice. This patch allows
platform bus_notifier to register IOMMU devices. Map info can be
passed from DT. Info format is:

  dma-window = <0 0x40000000>;

This is a fix for the following commit:

  commit 5688fbe0b3de2576e1f3f39e7477ebf9e5a9e49b
  platform: IOMMU'able platform_device w/ PLATFORM_ENABLE_IOMMU

bug 1286500

Change-Id: I80f2be03ff5c8a5b0a73254c0648084cfbcaf314
(cherry picked from commit 805b2bd223214015c1211998576bda8484d36b85)
Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
Reviewed-on: http://git-master/r/234110
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Krishna Reddy <vdumpa@nvidia.com>

1 files changed, 60 insertions, 1 deletions

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index f0053e4de00f..ee0d123dc045 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -32,9 +32,11 @@
 #include <linux/io.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
+#include <linux/of_iommu.h>
 
 #include <asm/page.h>
 #include <asm/cacheflush.h>
+#include <asm/dma-iommu.h>
 
 #include <mach/iomap.h>
 #include <mach/hardware.h>
@@ -1362,13 +1364,70 @@ static struct platform_driver tegra_smmu_driver = {
 	},
 };
 
+static int tegra_smmu_device_notifier(struct notifier_block *nb,
+				      unsigned long event, void *_dev)
+{
+	struct dma_iommu_mapping *map = tegra_smmu_get_map();
+	struct device *dev = _dev;
+	dma_addr_t base;
+	size_t size;
+	int err;
+
+	switch (event) {
+	case BUS_NOTIFY_ADD_DEVICE:
+		err = of_get_dma_window(dev->of_node, NULL, 0, NULL, &base,
+					&size);
+		if (!err)
+			map = arm_iommu_create_mapping(&platform_bus_type,
+						       base, size, 0);
+		if (IS_ERR_OR_NULL(map))
+			break;
+		if (arm_iommu_attach_device(dev, map)) {
+			arm_iommu_release_mapping(map);
+			dev_err(dev, "Failed to attach %s\n", dev_name(dev));
+			break;
+		}
+		dev_dbg(dev, "Attached %s to map %p\n", dev_name(dev), map);
+		break;
+	default:
+		break;
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block tegra_smmu_device_nb = {
+	.notifier_call = tegra_smmu_device_notifier,
+};
+
 static int __devinit tegra_smmu_init(void)
 {
-	return platform_driver_register(&tegra_smmu_driver);
+	int err;
+
+	err = platform_driver_register(&tegra_smmu_driver);
+	if (err)
+		return err;
+	if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU))
+		bus_register_notifier(&platform_bus_type,
+				      &tegra_smmu_device_nb);
+	return 0;
+}
+
+static int tegra_smmu_remove_map(struct device *dev, void *data)
+{
+	struct dma_iommu_mapping *map = to_dma_iommu_mapping(dev);
+	if (map)
+		arm_iommu_release_mapping(map);
+	return 0;
 }
 
 static void __exit tegra_smmu_exit(void)
 {
+	if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) {
+		bus_for_each_dev(&platform_bus_type, NULL, NULL,
+				 tegra_smmu_remove_map);
+		bus_unregister_notifier(&platform_bus_type,
+					&tegra_smmu_device_nb);
+	}
 	platform_driver_unregister(&tegra_smmu_driver);
 }