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_vblank.h>
27
28 #include "vkms_drv.h"
29
30 #define DRIVER_NAME "vkms"
31 #define DRIVER_DESC "Virtual Kernel Mode Setting"
32 #define DRIVER_DATE "20180514"
33 #define DRIVER_MAJOR 1
34 #define DRIVER_MINOR 0
35
36 static struct vkms_device *vkms_device;
37
38 bool enable_cursor = true;
39 module_param_named(enable_cursor, enable_cursor, bool, 0444);
40 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
41
42 static const struct file_operations vkms_driver_fops = {
43 .owner = THIS_MODULE,
44 .open = drm_open,
45 .mmap = drm_gem_mmap,
46 .unlocked_ioctl = drm_ioctl,
47 .compat_ioctl = drm_compat_ioctl,
48 .poll = drm_poll,
49 .read = drm_read,
50 .llseek = no_llseek,
51 .release = drm_release,
52 };
53
54 static const struct vm_operations_struct vkms_gem_vm_ops = {
55 .fault = vkms_gem_fault,
56 .open = drm_gem_vm_open,
57 .close = drm_gem_vm_close,
58 };
59
vkms_release(struct drm_device * dev)60 static void vkms_release(struct drm_device *dev)
61 {
62 struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
63
64 if (vkms->output.composer_workq)
65 destroy_workqueue(vkms->output.composer_workq);
66 }
67
vkms_atomic_commit_tail(struct drm_atomic_state * old_state)68 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
69 {
70 struct drm_device *dev = old_state->dev;
71 struct drm_crtc *crtc;
72 struct drm_crtc_state *old_crtc_state;
73 int i;
74
75 drm_atomic_helper_commit_modeset_disables(dev, old_state);
76
77 drm_atomic_helper_commit_planes(dev, old_state, 0);
78
79 drm_atomic_helper_commit_modeset_enables(dev, old_state);
80
81 drm_atomic_helper_fake_vblank(old_state);
82
83 drm_atomic_helper_commit_hw_done(old_state);
84
85 drm_atomic_helper_wait_for_flip_done(dev, old_state);
86
87 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
88 struct vkms_crtc_state *vkms_state =
89 to_vkms_crtc_state(old_crtc_state);
90
91 flush_work(&vkms_state->composer_work);
92 }
93
94 drm_atomic_helper_cleanup_planes(dev, old_state);
95 }
96
97 static struct drm_driver vkms_driver = {
98 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
99 .release = vkms_release,
100 .fops = &vkms_driver_fops,
101 .dumb_create = vkms_dumb_create,
102 .gem_vm_ops = &vkms_gem_vm_ops,
103 .gem_free_object_unlocked = vkms_gem_free_object,
104 .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
105 .gem_prime_import_sg_table = vkms_prime_import_sg_table,
106
107 .name = DRIVER_NAME,
108 .desc = DRIVER_DESC,
109 .date = DRIVER_DATE,
110 .major = DRIVER_MAJOR,
111 .minor = DRIVER_MINOR,
112 };
113
114 static const struct drm_mode_config_funcs vkms_mode_funcs = {
115 .fb_create = drm_gem_fb_create,
116 .atomic_check = drm_atomic_helper_check,
117 .atomic_commit = drm_atomic_helper_commit,
118 };
119
120 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
121 .atomic_commit_tail = vkms_atomic_commit_tail,
122 };
123
vkms_modeset_init(struct vkms_device * vkmsdev)124 static int vkms_modeset_init(struct vkms_device *vkmsdev)
125 {
126 struct drm_device *dev = &vkmsdev->drm;
127
128 drm_mode_config_init(dev);
129 dev->mode_config.funcs = &vkms_mode_funcs;
130 dev->mode_config.min_width = XRES_MIN;
131 dev->mode_config.min_height = YRES_MIN;
132 dev->mode_config.max_width = XRES_MAX;
133 dev->mode_config.max_height = YRES_MAX;
134 dev->mode_config.cursor_width = 512;
135 dev->mode_config.cursor_height = 512;
136 dev->mode_config.preferred_depth = 24;
137 dev->mode_config.helper_private = &vkms_mode_config_helpers;
138
139 return vkms_output_init(vkmsdev, 0);
140 }
141
vkms_init(void)142 static int __init vkms_init(void)
143 {
144 int ret;
145 struct platform_device *pdev;
146
147 pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
148 if (IS_ERR(pdev))
149 return PTR_ERR(pdev);
150
151 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
152 ret = -ENOMEM;
153 goto out_unregister;
154 }
155
156 vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver,
157 struct vkms_device, drm);
158 if (IS_ERR(vkms_device)) {
159 ret = PTR_ERR(vkms_device);
160 goto out_devres;
161 }
162 vkms_device->platform = pdev;
163
164 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
165 DMA_BIT_MASK(64));
166
167 if (ret) {
168 DRM_ERROR("Could not initialize DMA support\n");
169 goto out_devres;
170 }
171
172 vkms_device->drm.irq_enabled = true;
173
174 ret = drm_vblank_init(&vkms_device->drm, 1);
175 if (ret) {
176 DRM_ERROR("Failed to vblank\n");
177 goto out_devres;
178 }
179
180 ret = vkms_modeset_init(vkms_device);
181 if (ret)
182 goto out_devres;
183
184 ret = drm_dev_register(&vkms_device->drm, 0);
185 if (ret)
186 goto out_devres;
187
188 return 0;
189
190 out_devres:
191 devres_release_group(&pdev->dev, NULL);
192 out_unregister:
193 platform_device_unregister(pdev);
194 return ret;
195 }
196
vkms_exit(void)197 static void __exit vkms_exit(void)
198 {
199 struct platform_device *pdev;
200
201 if (!vkms_device) {
202 DRM_INFO("vkms_device is NULL.\n");
203 return;
204 }
205
206 pdev = vkms_device->platform;
207
208 drm_dev_unregister(&vkms_device->drm);
209 drm_atomic_helper_shutdown(&vkms_device->drm);
210 devres_release_group(&pdev->dev, NULL);
211 platform_device_unregister(pdev);
212 }
213
214 module_init(vkms_init);
215 module_exit(vkms_exit);
216
217 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
218 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
219 MODULE_DESCRIPTION(DRIVER_DESC);
220 MODULE_LICENSE("GPL");
221