summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/exynos/exynos_drm_iommu.c
blob: 055e8ec2ef212e831f4eaccf6ecfc3bd7ac76ba0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
/* 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)
		return 0;

	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);

	if (subdrv_dev->archdata.mapping)
		arm_iommu_detach_device(subdrv_dev);

	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 (get_dma_ops(dev) == get_dma_ops(NULL))
		set_dma_ops(dev, get_dma_ops(subdrv_dev));

	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);
}
OpenPOWER on IntegriCloud