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/device/faux.h> 14 #include <linux/dma-mapping.h> 15 16 #include <drm/clients/drm_client_setup.h> 17 #include <drm/drm_gem.h> 18 #include <drm/drm_atomic.h> 19 #include <drm/drm_atomic_helper.h> 20 #include <drm/drm_colorop.h> 21 #include <drm/drm_drv.h> 22 #include <drm/drm_fbdev_shmem.h> 23 #include <drm/drm_file.h> 24 #include <drm/drm_gem_framebuffer_helper.h> 25 #include <drm/drm_ioctl.h> 26 #include <drm/drm_managed.h> 27 #include <drm/drm_print.h> 28 #include <drm/drm_probe_helper.h> 29 #include <drm/drm_gem_shmem_helper.h> 30 #include <drm/drm_vblank.h> 31 32 #include "vkms_config.h" 33 #include "vkms_configfs.h" 34 #include "vkms_drv.h" 35 36 #define DRIVER_NAME "vkms" 37 #define DRIVER_DESC "Virtual Kernel Mode Setting" 38 #define DRIVER_MAJOR 1 39 #define DRIVER_MINOR 0 40 41 static struct vkms_config *default_config; 42 43 static bool enable_cursor = true; 44 module_param_named(enable_cursor, enable_cursor, bool, 0444); 45 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support"); 46 47 static bool enable_writeback = true; 48 module_param_named(enable_writeback, enable_writeback, bool, 0444); 49 MODULE_PARM_DESC(enable_writeback, "Enable/Disable writeback connector support"); 50 51 static bool enable_overlay; 52 module_param_named(enable_overlay, enable_overlay, bool, 0444); 53 MODULE_PARM_DESC(enable_overlay, "Enable/Disable overlay support"); 54 55 static bool enable_plane_pipeline; 56 module_param_named(enable_plane_pipeline, enable_plane_pipeline, bool, 0444); 57 MODULE_PARM_DESC(enable_plane_pipeline, "Enable/Disable plane pipeline support"); 58 59 static bool create_default_dev = true; 60 module_param_named(create_default_dev, create_default_dev, bool, 0444); 61 MODULE_PARM_DESC(create_default_dev, "Create or not the default VKMS device"); 62 63 DEFINE_DRM_GEM_FOPS(vkms_driver_fops); 64 65 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state) 66 { 67 struct drm_device *dev = old_state->dev; 68 struct drm_crtc *crtc; 69 struct drm_crtc_state *old_crtc_state; 70 int i; 71 72 drm_atomic_helper_commit_modeset_disables(dev, old_state); 73 74 drm_atomic_helper_commit_planes(dev, old_state, 0); 75 76 drm_atomic_helper_commit_modeset_enables(dev, old_state); 77 78 drm_atomic_helper_fake_vblank(old_state); 79 80 drm_atomic_helper_commit_hw_done(old_state); 81 82 drm_atomic_helper_wait_for_flip_done(dev, old_state); 83 84 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) { 85 struct vkms_crtc_state *vkms_state = 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 93 static const struct drm_driver vkms_driver = { 94 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM, 95 .fops = &vkms_driver_fops, 96 DRM_GEM_SHMEM_DRIVER_OPS, 97 DRM_FBDEV_SHMEM_DRIVER_OPS, 98 99 .name = DRIVER_NAME, 100 .desc = DRIVER_DESC, 101 .major = DRIVER_MAJOR, 102 .minor = DRIVER_MINOR, 103 }; 104 105 static int vkms_atomic_check(struct drm_device *dev, struct drm_atomic_state *state) 106 { 107 struct drm_crtc *crtc; 108 struct drm_crtc_state *new_crtc_state; 109 int i; 110 111 for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) { 112 if (!new_crtc_state->gamma_lut || !new_crtc_state->color_mgmt_changed) 113 continue; 114 115 if (new_crtc_state->gamma_lut->length / sizeof(struct drm_color_lut *) 116 > VKMS_LUT_SIZE) 117 return -EINVAL; 118 } 119 120 return drm_atomic_helper_check(dev, state); 121 } 122 123 static const struct drm_mode_config_funcs vkms_mode_funcs = { 124 .fb_create = drm_gem_fb_create, 125 .atomic_check = vkms_atomic_check, 126 .atomic_commit = drm_atomic_helper_commit, 127 }; 128 129 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = { 130 .atomic_commit_tail = vkms_atomic_commit_tail, 131 }; 132 133 static int vkms_modeset_init(struct vkms_device *vkmsdev) 134 { 135 struct drm_device *dev = &vkmsdev->drm; 136 int ret; 137 138 ret = drmm_mode_config_init(dev); 139 if (ret) 140 return ret; 141 142 dev->mode_config.funcs = &vkms_mode_funcs; 143 dev->mode_config.min_width = XRES_MIN; 144 dev->mode_config.min_height = YRES_MIN; 145 dev->mode_config.max_width = XRES_MAX; 146 dev->mode_config.max_height = YRES_MAX; 147 dev->mode_config.cursor_width = 512; 148 dev->mode_config.cursor_height = 512; 149 /* 150 * FIXME: There's a confusion between bpp and depth between this and 151 * fbdev helpers. We have to go with 0, meaning "pick the default", 152 * which is XRGB8888 in all cases. 153 */ 154 dev->mode_config.preferred_depth = 0; 155 dev->mode_config.helper_private = &vkms_mode_config_helpers; 156 157 return vkms_output_init(vkmsdev); 158 } 159 160 int vkms_create(struct vkms_config *config) 161 { 162 int ret; 163 struct faux_device *fdev; 164 struct vkms_device *vkms_device; 165 const char *dev_name; 166 167 dev_name = vkms_config_get_device_name(config); 168 fdev = faux_device_create(dev_name, NULL, NULL); 169 if (!fdev) 170 return -ENODEV; 171 172 if (!devres_open_group(&fdev->dev, NULL, GFP_KERNEL)) { 173 ret = -ENOMEM; 174 goto out_unregister; 175 } 176 177 vkms_device = devm_drm_dev_alloc(&fdev->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->faux_dev = fdev; 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, 196 vkms_config_get_num_crtcs(config)); 197 if (ret) { 198 DRM_ERROR("Failed to vblank\n"); 199 goto out_devres; 200 } 201 202 ret = vkms_modeset_init(vkms_device); 203 if (ret) 204 goto out_devres; 205 206 vkms_config_register_debugfs(vkms_device); 207 208 ret = drm_dev_register(&vkms_device->drm, 0); 209 if (ret) 210 goto out_devres; 211 212 drm_client_setup(&vkms_device->drm, NULL); 213 214 return 0; 215 216 out_devres: 217 devres_release_group(&fdev->dev, NULL); 218 out_unregister: 219 faux_device_destroy(fdev); 220 return ret; 221 } 222 223 static int __init vkms_init(void) 224 { 225 int ret; 226 struct vkms_config *config; 227 228 ret = vkms_configfs_register(); 229 if (ret) 230 return ret; 231 232 if (!create_default_dev) 233 return 0; 234 235 config = vkms_config_default_create(enable_cursor, enable_writeback, 236 enable_overlay, enable_plane_pipeline); 237 if (IS_ERR(config)) 238 return PTR_ERR(config); 239 240 ret = vkms_create(config); 241 if (ret) { 242 vkms_config_destroy(config); 243 return ret; 244 } 245 246 default_config = config; 247 248 return 0; 249 } 250 251 void vkms_destroy(struct vkms_config *config) 252 { 253 struct faux_device *fdev; 254 255 if (!config->dev) { 256 DRM_INFO("vkms_device is NULL.\n"); 257 return; 258 } 259 260 fdev = config->dev->faux_dev; 261 262 drm_colorop_pipeline_destroy(&config->dev->drm); 263 drm_dev_unregister(&config->dev->drm); 264 drm_atomic_helper_shutdown(&config->dev->drm); 265 devres_release_group(&fdev->dev, NULL); 266 faux_device_destroy(fdev); 267 268 config->dev = NULL; 269 } 270 271 static void __exit vkms_exit(void) 272 { 273 vkms_configfs_unregister(); 274 275 if (!default_config) 276 return; 277 278 vkms_destroy(default_config); 279 vkms_config_destroy(default_config); 280 } 281 282 module_init(vkms_init); 283 module_exit(vkms_exit); 284 285 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>"); 286 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>"); 287 MODULE_DESCRIPTION(DRIVER_DESC); 288 MODULE_LICENSE("GPL"); 289