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