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 destroy_workqueue(vkms->output.composer_workq);
65 }
66
vkms_atomic_commit_tail(struct drm_atomic_state * old_state)67 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
68 {
69 struct drm_device *dev = old_state->dev;
70 struct drm_crtc *crtc;
71 struct drm_crtc_state *old_crtc_state;
72 int i;
73
74 drm_atomic_helper_commit_modeset_disables(dev, old_state);
75
76 drm_atomic_helper_commit_planes(dev, old_state, 0);
77
78 drm_atomic_helper_commit_modeset_enables(dev, old_state);
79
80 drm_atomic_helper_fake_vblank(old_state);
81
82 drm_atomic_helper_commit_hw_done(old_state);
83
84 drm_atomic_helper_wait_for_flip_done(dev, old_state);
85
86 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
87 struct vkms_crtc_state *vkms_state =
88 to_vkms_crtc_state(old_crtc_state);
89
90 flush_work(&vkms_state->composer_work);
91 }
92
93 drm_atomic_helper_cleanup_planes(dev, old_state);
94 }
95
96 static struct drm_driver vkms_driver = {
97 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
98 .release = vkms_release,
99 .fops = &vkms_driver_fops,
100 .dumb_create = vkms_dumb_create,
101 .gem_vm_ops = &vkms_gem_vm_ops,
102 .gem_free_object_unlocked = vkms_gem_free_object,
103 .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
104 .gem_prime_import_sg_table = vkms_prime_import_sg_table,
105
106 .name = DRIVER_NAME,
107 .desc = DRIVER_DESC,
108 .date = DRIVER_DATE,
109 .major = DRIVER_MAJOR,
110 .minor = DRIVER_MINOR,
111 };
112
113 static const struct drm_mode_config_funcs vkms_mode_funcs = {
114 .fb_create = drm_gem_fb_create,
115 .atomic_check = drm_atomic_helper_check,
116 .atomic_commit = drm_atomic_helper_commit,
117 };
118
119 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
120 .atomic_commit_tail = vkms_atomic_commit_tail,
121 };
122
vkms_modeset_init(struct vkms_device * vkmsdev)123 static int vkms_modeset_init(struct vkms_device *vkmsdev)
124 {
125 struct drm_device *dev = &vkmsdev->drm;
126
127 drm_mode_config_init(dev);
128 dev->mode_config.funcs = &vkms_mode_funcs;
129 dev->mode_config.min_width = XRES_MIN;
130 dev->mode_config.min_height = YRES_MIN;
131 dev->mode_config.max_width = XRES_MAX;
132 dev->mode_config.max_height = YRES_MAX;
133 dev->mode_config.cursor_width = 512;
134 dev->mode_config.cursor_height = 512;
135 dev->mode_config.preferred_depth = 24;
136 dev->mode_config.helper_private = &vkms_mode_config_helpers;
137
138 return vkms_output_init(vkmsdev, 0);
139 }
140
vkms_init(void)141 static int __init vkms_init(void)
142 {
143 int ret;
144 struct platform_device *pdev;
145
146 pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
147 if (IS_ERR(pdev))
148 return PTR_ERR(pdev);
149
150 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
151 ret = -ENOMEM;
152 goto out_unregister;
153 }
154
155 vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver,
156 struct vkms_device, drm);
157 if (IS_ERR(vkms_device)) {
158 ret = PTR_ERR(vkms_device);
159 goto out_devres;
160 }
161 vkms_device->platform = pdev;
162
163 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
164 DMA_BIT_MASK(64));
165
166 if (ret) {
167 DRM_ERROR("Could not initialize DMA support\n");
168 goto out_devres;
169 }
170
171 vkms_device->drm.irq_enabled = true;
172
173 ret = drm_vblank_init(&vkms_device->drm, 1);
174 if (ret) {
175 DRM_ERROR("Failed to vblank\n");
176 goto out_devres;
177 }
178
179 ret = vkms_modeset_init(vkms_device);
180 if (ret)
181 goto out_devres;
182
183 ret = drm_dev_register(&vkms_device->drm, 0);
184 if (ret)
185 goto out_devres;
186
187 return 0;
188
189 out_devres:
190 devres_release_group(&pdev->dev, NULL);
191 out_unregister:
192 platform_device_unregister(pdev);
193 return ret;
194 }
195
vkms_exit(void)196 static void __exit vkms_exit(void)
197 {
198 struct platform_device *pdev;
199
200 if (!vkms_device) {
201 DRM_INFO("vkms_device is NULL.\n");
202 return;
203 }
204
205 pdev = vkms_device->platform;
206
207 drm_dev_unregister(&vkms_device->drm);
208 drm_atomic_helper_shutdown(&vkms_device->drm);
209 devres_release_group(&pdev->dev, NULL);
210 platform_device_unregister(pdev);
211 }
212
213 module_init(vkms_init);
214 module_exit(vkms_exit);
215
216 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
217 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
218 MODULE_DESCRIPTION(DRIVER_DESC);
219 MODULE_LICENSE("GPL");
220