3 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
4 * Author: Inki Dae <inki.dae@samsung.com>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
13 #include <drm/exynos_drm.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/iommu.h>
17 #include <linux/kref.h>
19 #include <asm/dma-iommu.h>
21 #include "exynos_drm_drv.h"
22 #include "exynos_drm_iommu.h"
25 * drm_create_iommu_mapping - create a mapping structure
27 * @drm_dev: DRM device
29 int drm_create_iommu_mapping(struct drm_device *drm_dev)
31 struct dma_iommu_mapping *mapping = NULL;
32 struct exynos_drm_private *priv = drm_dev->dev_private;
33 struct device *dev = drm_dev->dev;
36 priv->da_start = EXYNOS_DEV_ADDR_START;
37 if (!priv->da_space_size)
38 priv->da_space_size = EXYNOS_DEV_ADDR_SIZE;
40 mapping = arm_iommu_create_mapping(&platform_bus_type, priv->da_start,
44 return PTR_ERR(mapping);
46 dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
51 dma_set_max_seg_size(dev, 0xffffffffu);
52 dev->archdata.mapping = mapping;
56 arm_iommu_release_mapping(mapping);
61 * drm_release_iommu_mapping - release iommu mapping structure
63 * @drm_dev: DRM device
65 * if mapping->kref becomes 0 then all things related to iommu mapping
68 void drm_release_iommu_mapping(struct drm_device *drm_dev)
70 struct device *dev = drm_dev->dev;
72 arm_iommu_release_mapping(dev->archdata.mapping);
76 * drm_iommu_attach_device- attach device to iommu mapping
78 * @drm_dev: DRM device
79 * @subdrv_dev: device to be attach
81 * This function should be called by sub drivers to attach it to iommu
84 int drm_iommu_attach_device(struct drm_device *drm_dev,
85 struct device *subdrv_dev)
87 struct device *dev = drm_dev->dev;
90 if (!dev->archdata.mapping) {
91 DRM_ERROR("iommu_mapping is null.\n");
95 subdrv_dev->dma_parms = devm_kzalloc(subdrv_dev,
96 sizeof(*subdrv_dev->dma_parms),
98 if (!subdrv_dev->dma_parms)
101 dma_set_max_seg_size(subdrv_dev, 0xffffffffu);
103 ret = arm_iommu_attach_device(subdrv_dev, dev->archdata.mapping);
105 DRM_DEBUG_KMS("failed iommu attach.\n");
110 * Set dma_ops to drm_device just one time.
112 * The dma mapping api needs device object and the api is used
113 * to allocate physial memory and map it with iommu table.
114 * If iommu attach succeeded, the sub driver would have dma_ops
115 * for iommu and also all sub drivers have same dma_ops.
117 if (!dev->archdata.dma_ops)
118 dev->archdata.dma_ops = subdrv_dev->archdata.dma_ops;
124 * drm_iommu_detach_device -detach device address space mapping from device
126 * @drm_dev: DRM device
127 * @subdrv_dev: device to be detached
129 * This function should be called by sub drivers to detach it from iommu
132 void drm_iommu_detach_device(struct drm_device *drm_dev,
133 struct device *subdrv_dev)
135 struct device *dev = drm_dev->dev;
136 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
138 if (!mapping || !mapping->domain)
141 iommu_detach_device(mapping->domain, subdrv_dev);
142 drm_release_iommu_mapping(drm_dev);