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 #include <drm/drm_print.h>
32 #include <drm/drm_debugfs.h>
33
34 #define DRIVER_NAME "vkms"
35 #define DRIVER_DESC "Virtual Kernel Mode Setting"
36 #define DRIVER_DATE "20180514"
37 #define DRIVER_MAJOR 1
38 #define DRIVER_MINOR 0
39
40 static struct vkms_config *default_config;
41
42 static bool enable_cursor = true;
43 module_param_named(enable_cursor, enable_cursor, bool, 0444);
44 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
45
46 static bool enable_writeback = true;
47 module_param_named(enable_writeback, enable_writeback, bool, 0444);
48 MODULE_PARM_DESC(enable_writeback, "Enable/Disable writeback connector support");
49
50 static bool enable_overlay;
51 module_param_named(enable_overlay, enable_overlay, bool, 0444);
52 MODULE_PARM_DESC(enable_overlay, "Enable/Disable overlay support");
53
54 DEFINE_DRM_GEM_FOPS(vkms_driver_fops);
55
vkms_release(struct drm_device * dev)56 static void vkms_release(struct drm_device *dev)
57 {
58 struct vkms_device *vkms = drm_device_to_vkms_device(dev);
59
60 if (vkms->output.composer_workq)
61 destroy_workqueue(vkms->output.composer_workq);
62 }
63
vkms_atomic_commit_tail(struct drm_atomic_state * old_state)64 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
65 {
66 struct drm_device *dev = old_state->dev;
67 struct drm_crtc *crtc;
68 struct drm_crtc_state *old_crtc_state;
69 int i;
70
71 drm_atomic_helper_commit_modeset_disables(dev, old_state);
72
73 drm_atomic_helper_commit_planes(dev, old_state, 0);
74
75 drm_atomic_helper_commit_modeset_enables(dev, old_state);
76
77 drm_atomic_helper_fake_vblank(old_state);
78
79 drm_atomic_helper_commit_hw_done(old_state);
80
81 drm_atomic_helper_wait_for_flip_done(dev, old_state);
82
83 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
84 struct vkms_crtc_state *vkms_state =
85 to_vkms_crtc_state(old_crtc_state);
86
87 flush_work(&vkms_state->composer_work);
88 }
89
90 drm_atomic_helper_cleanup_planes(dev, old_state);
91 }
92
vkms_config_show(struct seq_file * m,void * data)93 static int vkms_config_show(struct seq_file *m, void *data)
94 {
95 struct drm_info_node *node = (struct drm_info_node *)m->private;
96 struct drm_device *dev = node->minor->dev;
97 struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
98
99 seq_printf(m, "writeback=%d\n", vkmsdev->config->writeback);
100 seq_printf(m, "cursor=%d\n", vkmsdev->config->cursor);
101 seq_printf(m, "overlay=%d\n", vkmsdev->config->overlay);
102
103 return 0;
104 }
105
106 static const struct drm_info_list vkms_config_debugfs_list[] = {
107 { "vkms_config", vkms_config_show, 0 },
108 };
109
vkms_config_debugfs_init(struct drm_minor * minor)110 static void vkms_config_debugfs_init(struct drm_minor *minor)
111 {
112 drm_debugfs_create_files(vkms_config_debugfs_list, ARRAY_SIZE(vkms_config_debugfs_list),
113 minor->debugfs_root, minor);
114 }
115
116 static const struct drm_driver vkms_driver = {
117 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
118 .release = vkms_release,
119 .fops = &vkms_driver_fops,
120 DRM_GEM_SHMEM_DRIVER_OPS,
121
122 .debugfs_init = vkms_config_debugfs_init,
123
124 .name = DRIVER_NAME,
125 .desc = DRIVER_DESC,
126 .date = DRIVER_DATE,
127 .major = DRIVER_MAJOR,
128 .minor = DRIVER_MINOR,
129 };
130
131 static const struct drm_mode_config_funcs vkms_mode_funcs = {
132 .fb_create = drm_gem_fb_create,
133 .atomic_check = drm_atomic_helper_check,
134 .atomic_commit = drm_atomic_helper_commit,
135 };
136
137 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
138 .atomic_commit_tail = vkms_atomic_commit_tail,
139 };
140
vkms_modeset_init(struct vkms_device * vkmsdev)141 static int vkms_modeset_init(struct vkms_device *vkmsdev)
142 {
143 struct drm_device *dev = &vkmsdev->drm;
144
145 drm_mode_config_init(dev);
146 dev->mode_config.funcs = &vkms_mode_funcs;
147 dev->mode_config.min_width = XRES_MIN;
148 dev->mode_config.min_height = YRES_MIN;
149 dev->mode_config.max_width = XRES_MAX;
150 dev->mode_config.max_height = YRES_MAX;
151 dev->mode_config.cursor_width = 512;
152 dev->mode_config.cursor_height = 512;
153 /* FIXME: There's a confusion between bpp and depth between this and
154 * fbdev helpers. We have to go with 0, meaning "pick the default",
155 * which ix XRGB8888 in all cases. */
156 dev->mode_config.preferred_depth = 0;
157 dev->mode_config.helper_private = &vkms_mode_config_helpers;
158
159 return vkms_output_init(vkmsdev, 0);
160 }
161
vkms_create(struct vkms_config * config)162 static int vkms_create(struct vkms_config *config)
163 {
164 int ret;
165 struct platform_device *pdev;
166 struct vkms_device *vkms_device;
167
168 pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
169 if (IS_ERR(pdev))
170 return PTR_ERR(pdev);
171
172 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
173 ret = -ENOMEM;
174 goto out_unregister;
175 }
176
177 vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver,
178 struct vkms_device, drm);
179 if (IS_ERR(vkms_device)) {
180 ret = PTR_ERR(vkms_device);
181 goto out_devres;
182 }
183 vkms_device->platform = pdev;
184 vkms_device->config = config;
185 config->dev = vkms_device;
186
187 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
188 DMA_BIT_MASK(64));
189
190 if (ret) {
191 DRM_ERROR("Could not initialize DMA support\n");
192 goto out_devres;
193 }
194
195 ret = drm_vblank_init(&vkms_device->drm, 1);
196 if (ret) {
197 DRM_ERROR("Failed to vblank\n");
198 goto out_devres;
199 }
200
201 ret = vkms_modeset_init(vkms_device);
202 if (ret)
203 goto out_devres;
204
205 ret = drm_dev_register(&vkms_device->drm, 0);
206 if (ret)
207 goto out_devres;
208
209 drm_fbdev_generic_setup(&vkms_device->drm, 0);
210
211 return 0;
212
213 out_devres:
214 devres_release_group(&pdev->dev, NULL);
215 out_unregister:
216 platform_device_unregister(pdev);
217 return ret;
218 }
219
vkms_init(void)220 static int __init vkms_init(void)
221 {
222 int ret;
223 struct vkms_config *config;
224
225 config = kmalloc(sizeof(*config), GFP_KERNEL);
226 if (!config)
227 return -ENOMEM;
228
229 default_config = config;
230
231 config->cursor = enable_cursor;
232 config->writeback = enable_writeback;
233 config->overlay = enable_overlay;
234
235 ret = vkms_create(config);
236 if (ret)
237 kfree(config);
238
239 return ret;
240 }
241
vkms_destroy(struct vkms_config * config)242 static void vkms_destroy(struct vkms_config *config)
243 {
244 struct platform_device *pdev;
245
246 if (!config->dev) {
247 DRM_INFO("vkms_device is NULL.\n");
248 return;
249 }
250
251 pdev = config->dev->platform;
252
253 drm_dev_unregister(&config->dev->drm);
254 drm_atomic_helper_shutdown(&config->dev->drm);
255 devres_release_group(&pdev->dev, NULL);
256 platform_device_unregister(pdev);
257
258 config->dev = NULL;
259 }
260
vkms_exit(void)261 static void __exit vkms_exit(void)
262 {
263 if (default_config->dev)
264 vkms_destroy(default_config);
265
266 kfree(default_config);
267 }
268
269 module_init(vkms_init);
270 module_exit(vkms_exit);
271
272 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
273 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
274 MODULE_DESCRIPTION(DRIVER_DESC);
275 MODULE_LICENSE("GPL");
276