1 files changed, 143 insertions, 0 deletions
diff --git a/drivers/gpu/drm/exynos/exynos_drm_iommu.c b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
new file mode 100644
index 000000000..b32b291f8
--- /dev/null
+++ b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
@@ -0,0 +1,143 @@
+/* exynos_drm_iommu.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ * Author: Inki Dae <inki.dae@samsung.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <drmP.h>
+#include <drm/exynos_drm.h>
+
+#include <linux/dma-mapping.h>
+#include <linux/iommu.h>
+#include <linux/kref.h>
+
+#include <asm/dma-iommu.h>
+
+#include "exynos_drm_drv.h"
+#include "exynos_drm_iommu.h"
+
+/*
+ * drm_create_iommu_mapping - create a mapping structure
+ *
+ * @drm_dev: DRM device
+ */
+int drm_create_iommu_mapping(struct drm_device *drm_dev)
+{
+	struct dma_iommu_mapping *mapping = NULL;
+	struct exynos_drm_private *priv = drm_dev->dev_private;
+	struct device *dev = drm_dev->dev;
+
+	if (!priv->da_start)
+		priv->da_start = EXYNOS_DEV_ADDR_START;
+	if (!priv->da_space_size)
+		priv->da_space_size = EXYNOS_DEV_ADDR_SIZE;
+
+	mapping = arm_iommu_create_mapping(&platform_bus_type, priv->da_start,
+						priv->da_space_size);
+
+	if (IS_ERR(mapping))
+		return PTR_ERR(mapping);
+
+	dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
+					GFP_KERNEL);
+	if (!dev->dma_parms)
+		goto error;
+
+	dma_set_max_seg_size(dev, 0xffffffffu);
+	dev->archdata.mapping = mapping;
+
+	return 0;
+error:
+	arm_iommu_release_mapping(mapping);
+	return -ENOMEM;
+}
+
+/*
+ * drm_release_iommu_mapping - release iommu mapping structure
+ *
+ * @drm_dev: DRM device
+ *
+ * if mapping->kref becomes 0 then all things related to iommu mapping
+ * will be released
+ */
+void drm_release_iommu_mapping(struct drm_device *drm_dev)
+{
+	struct device *dev = drm_dev->dev;
+
+	arm_iommu_release_mapping(dev->archdata.mapping);
+}
+
+/*
+ * drm_iommu_attach_device- attach device to iommu mapping
+ *
+ * @drm_dev: DRM device
+ * @subdrv_dev: device to be attach
+ *
+ * This function should be called by sub drivers to attach it to iommu
+ * mapping.
+ */
+int drm_iommu_attach_device(struct drm_device *drm_dev,
+				struct device *subdrv_dev)
+{
+	struct device *dev = drm_dev->dev;
+	int ret;
+
+	if (!dev->archdata.mapping) {
+		DRM_ERROR("iommu_mapping is null.\n");
+		return -EFAULT;
+	}
+
+	subdrv_dev->dma_parms = devm_kzalloc(subdrv_dev,
+					sizeof(*subdrv_dev->dma_parms),
+					GFP_KERNEL);
+	if (!subdrv_dev->dma_parms)
+		return -ENOMEM;
+
+	dma_set_max_seg_size(subdrv_dev, 0xffffffffu);
+
+	ret = arm_iommu_attach_device(subdrv_dev, dev->archdata.mapping);
+	if (ret < 0) {
+		DRM_DEBUG_KMS("failed iommu attach.\n");
+		return ret;
+	}
+
+	/*
+	 * Set dma_ops to drm_device just one time.
+	 *
+	 * The dma mapping api needs device object and the api is used
+	 * to allocate physial memory and map it with iommu table.
+	 * If iommu attach succeeded, the sub driver would have dma_ops
+	 * for iommu and also all sub drivers have same dma_ops.
+	 */
+	if (!dev->archdata.dma_ops)
+		dev->archdata.dma_ops = subdrv_dev->archdata.dma_ops;
+
+	return 0;
+}
+
+/*
+ * drm_iommu_detach_device -detach device address space mapping from device
+ *
+ * @drm_dev: DRM device
+ * @subdrv_dev: device to be detached
+ *
+ * This function should be called by sub drivers to detach it from iommu
+ * mapping
+ */
+void drm_iommu_detach_device(struct drm_device *drm_dev,
+				struct device *subdrv_dev)
+{
+	struct device *dev = drm_dev->dev;
+	struct dma_iommu_mapping *mapping = dev->archdata.mapping;
+
+	if (!mapping || !mapping->domain)
+		return;
+
+	iommu_detach_device(mapping->domain, subdrv_dev);
+	drm_release_iommu_mapping(drm_dev);
+}