[PATCH 1/1] ARM: tegra: bus_notifier registers IOMMU devices

[Hiroshi Doyu]

platform_bus notifier registers IOMMU devices if dma-window is
specified.

Its format is:
  dma-window = <"start" "size">;
ex)
  dma-window = <0x12345000 0x8000>;

Signed-off-by: Hiroshi Doyu <hdoyu@xxxxxxxxxx>
---
 arch/arm/mach-tegra/board-dt-tegra30.c |   40 ++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/arch/arm/mach-tegra/board-dt-tegra30.c b/arch/arm/mach-tegra/board-dt-tegra30.c
index a2b6cf1..570d718 100644
--- a/arch/arm/mach-tegra/board-dt-tegra30.c
+++ b/arch/arm/mach-tegra/board-dt-tegra30.c
@@ -30,9 +30,11 @@
 #include <linux/of_fdt.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
+#include <linux/of_iommu.h>
 
 #include <asm/mach/arch.h>
 #include <asm/hardware/gic.h>
+#include <asm/dma-iommu.h>
 
 #include "board.h"
 #include "clock.h"
@@ -86,10 +88,48 @@ static __initdata struct tegra_clk_init_table tegra_dt_clk_init_table[] = {
 	{ NULL,		NULL,		0,		0},
 };
 
+#ifdef CONFIG_ARM_DMA_USE_IOMMU
+static int tegra_iommu_device_notifier(struct notifier_block *nb,
+				       unsigned long event, void *_dev)
+{
+	struct dma_iommu_mapping *map = NULL;
+	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))
+			dev_err(dev, "Failed to attach %s\n", dev_name(dev));
+		dev_dbg(dev, "Attached %s to map %p\n", dev_name(dev), map);
+		break;
+	}
+	return NOTIFY_DONE;
+}
+#else
+#define tegra_iommu_device_notifier NULL
+#endif
+
+static struct notifier_block tegra_iommu_device_nb = {
+	.notifier_call = tegra_iommu_device_notifier,
+};
+
 static void __init tegra30_dt_init(void)
 {
 	tegra_clk_init_from_table(tegra_dt_clk_init_table);
 
+	if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU))
+		bus_register_notifier(&platform_bus_type,
+				      &tegra_iommu_device_nb);
+
 	of_platform_populate(NULL, of_default_bus_match_table,
 				tegra30_auxdata_lookup, NULL);
 }
-- 
1.7.9.5
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