tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0+
2
3/**
4 * DOC: vkms (Virtual Kernel Modesetting)
5 *
6 * VKMS is a software-only model of a KMS driver that is useful for testing
7 * and for running X (or similar) on headless machines. VKMS aims to enable
8 * a virtual display with no need of a hardware display capability, releasing
9 * the GPU in DRM API tests.
10 */
11
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/dma-mapping.h>
15
16#include <drm/drm_gem.h>
17#include <drm/drm_atomic.h>
18#include <drm/drm_atomic_helper.h>
19#include <drm/drm_drv.h>
20#include <drm/drm_fb_helper.h>
21#include <drm/drm_file.h>
22#include <drm/drm_gem_framebuffer_helper.h>
23#include <drm/drm_ioctl.h>
24#include <drm/drm_managed.h>
25#include <drm/drm_probe_helper.h>
26#include <drm/drm_gem_shmem_helper.h>
27#include <drm/drm_vblank.h>
28
29#include "vkms_drv.h"
30
31#define DRIVER_NAME "vkms"
32#define DRIVER_DESC "Virtual Kernel Mode Setting"
33#define DRIVER_DATE "20180514"
34#define DRIVER_MAJOR 1
35#define DRIVER_MINOR 0
36
37static struct vkms_config *default_config;
38
39static bool enable_cursor = true;
40module_param_named(enable_cursor, enable_cursor, bool, 0444);
41MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
42
43static bool enable_writeback = true;
44module_param_named(enable_writeback, enable_writeback, bool, 0444);
45MODULE_PARM_DESC(enable_writeback, "Enable/Disable writeback connector support");
46
47DEFINE_DRM_GEM_FOPS(vkms_driver_fops);
48
49static void vkms_release(struct drm_device *dev)
50{
51 struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
52
53 destroy_workqueue(vkms->output.composer_workq);
54}
55
56static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
57{
58 struct drm_device *dev = old_state->dev;
59 struct drm_crtc *crtc;
60 struct drm_crtc_state *old_crtc_state;
61 int i;
62
63 drm_atomic_helper_commit_modeset_disables(dev, old_state);
64
65 drm_atomic_helper_commit_planes(dev, old_state, 0);
66
67 drm_atomic_helper_commit_modeset_enables(dev, old_state);
68
69 drm_atomic_helper_fake_vblank(old_state);
70
71 drm_atomic_helper_commit_hw_done(old_state);
72
73 drm_atomic_helper_wait_for_flip_done(dev, old_state);
74
75 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
76 struct vkms_crtc_state *vkms_state =
77 to_vkms_crtc_state(old_crtc_state);
78
79 flush_work(&vkms_state->composer_work);
80 }
81
82 drm_atomic_helper_cleanup_planes(dev, old_state);
83}
84
85static const struct drm_driver vkms_driver = {
86 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
87 .release = vkms_release,
88 .fops = &vkms_driver_fops,
89 DRM_GEM_SHMEM_DRIVER_OPS,
90
91 .name = DRIVER_NAME,
92 .desc = DRIVER_DESC,
93 .date = DRIVER_DATE,
94 .major = DRIVER_MAJOR,
95 .minor = DRIVER_MINOR,
96};
97
98static const struct drm_mode_config_funcs vkms_mode_funcs = {
99 .fb_create = drm_gem_fb_create,
100 .atomic_check = drm_atomic_helper_check,
101 .atomic_commit = drm_atomic_helper_commit,
102};
103
104static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
105 .atomic_commit_tail = vkms_atomic_commit_tail,
106};
107
108static int vkms_modeset_init(struct vkms_device *vkmsdev)
109{
110 struct drm_device *dev = &vkmsdev->drm;
111
112 drm_mode_config_init(dev);
113 dev->mode_config.funcs = &vkms_mode_funcs;
114 dev->mode_config.min_width = XRES_MIN;
115 dev->mode_config.min_height = YRES_MIN;
116 dev->mode_config.max_width = XRES_MAX;
117 dev->mode_config.max_height = YRES_MAX;
118 dev->mode_config.cursor_width = 512;
119 dev->mode_config.cursor_height = 512;
120 /* FIXME: There's a confusion between bpp and depth between this and
121 * fbdev helpers. We have to go with 0, meaning "pick the default",
122 * which ix XRGB8888 in all cases. */
123 dev->mode_config.preferred_depth = 0;
124 dev->mode_config.helper_private = &vkms_mode_config_helpers;
125
126 return vkms_output_init(vkmsdev, 0);
127}
128
129static int vkms_create(struct vkms_config *config)
130{
131 int ret;
132 struct platform_device *pdev;
133 struct vkms_device *vkms_device;
134
135 pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
136 if (IS_ERR(pdev))
137 return PTR_ERR(pdev);
138
139 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
140 ret = -ENOMEM;
141 goto out_unregister;
142 }
143
144 vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver,
145 struct vkms_device, drm);
146 if (IS_ERR(vkms_device)) {
147 ret = PTR_ERR(vkms_device);
148 goto out_devres;
149 }
150 vkms_device->platform = pdev;
151 vkms_device->config = config;
152 config->dev = vkms_device;
153
154 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
155 DMA_BIT_MASK(64));
156
157 if (ret) {
158 DRM_ERROR("Could not initialize DMA support\n");
159 goto out_devres;
160 }
161
162 vkms_device->drm.irq_enabled = true;
163
164 ret = drm_vblank_init(&vkms_device->drm, 1);
165 if (ret) {
166 DRM_ERROR("Failed to vblank\n");
167 goto out_devres;
168 }
169
170 ret = vkms_modeset_init(vkms_device);
171 if (ret)
172 goto out_devres;
173
174 ret = drm_dev_register(&vkms_device->drm, 0);
175 if (ret)
176 goto out_devres;
177
178 drm_fbdev_generic_setup(&vkms_device->drm, 0);
179
180 return 0;
181
182out_devres:
183 devres_release_group(&pdev->dev, NULL);
184out_unregister:
185 platform_device_unregister(pdev);
186 return ret;
187}
188
189static int __init vkms_init(void)
190{
191 struct vkms_config *config;
192
193 config = kmalloc(sizeof(*config), GFP_KERNEL);
194 if (!config)
195 return -ENOMEM;
196
197 default_config = config;
198
199 config->cursor = enable_cursor;
200 config->writeback = enable_writeback;
201
202 return vkms_create(config);
203}
204
205static void vkms_destroy(struct vkms_config *config)
206{
207 struct platform_device *pdev;
208
209 if (!config->dev) {
210 DRM_INFO("vkms_device is NULL.\n");
211 return;
212 }
213
214 pdev = config->dev->platform;
215
216 drm_dev_unregister(&config->dev->drm);
217 drm_atomic_helper_shutdown(&config->dev->drm);
218 devres_release_group(&pdev->dev, NULL);
219 platform_device_unregister(pdev);
220
221 config->dev = NULL;
222}
223
224static void __exit vkms_exit(void)
225{
226 if (default_config->dev)
227 vkms_destroy(default_config);
228
229 kfree(default_config);
230}
231
232module_init(vkms_init);
233module_exit(vkms_exit);
234
235MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
236MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
237MODULE_DESCRIPTION(DRIVER_DESC);
238MODULE_LICENSE("GPL");