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_probe_helper.h> 25 #include <drm/drm_vblank.h> 26 27 #include "vkms_drv.h" 28 29 #define DRIVER_NAME "vkms" 30 #define DRIVER_DESC "Virtual Kernel Mode Setting" 31 #define DRIVER_DATE "20180514" 32 #define DRIVER_MAJOR 1 33 #define DRIVER_MINOR 0 34 35 static struct vkms_device *vkms_device; 36 37 bool enable_cursor; 38 module_param_named(enable_cursor, enable_cursor, bool, 0444); 39 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support"); 40 41 static const struct file_operations vkms_driver_fops = { 42 .owner = THIS_MODULE, 43 .open = drm_open, 44 .mmap = drm_gem_mmap, 45 .unlocked_ioctl = drm_ioctl, 46 .compat_ioctl = drm_compat_ioctl, 47 .poll = drm_poll, 48 .read = drm_read, 49 .llseek = no_llseek, 50 .release = drm_release, 51 }; 52 53 static const struct vm_operations_struct vkms_gem_vm_ops = { 54 .fault = vkms_gem_fault, 55 .open = drm_gem_vm_open, 56 .close = drm_gem_vm_close, 57 }; 58 59 static void vkms_release(struct drm_device *dev) 60 { 61 struct vkms_device *vkms = container_of(dev, struct vkms_device, drm); 62 63 platform_device_unregister(vkms->platform); 64 drm_atomic_helper_shutdown(&vkms->drm); 65 drm_mode_config_cleanup(&vkms->drm); 66 drm_dev_fini(&vkms->drm); 67 destroy_workqueue(vkms->output.composer_workq); 68 } 69 70 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state) 71 { 72 struct drm_device *dev = old_state->dev; 73 struct drm_crtc *crtc; 74 struct drm_crtc_state *old_crtc_state; 75 int i; 76 77 drm_atomic_helper_commit_modeset_disables(dev, old_state); 78 79 drm_atomic_helper_commit_planes(dev, old_state, 0); 80 81 drm_atomic_helper_commit_modeset_enables(dev, old_state); 82 83 drm_atomic_helper_fake_vblank(old_state); 84 85 drm_atomic_helper_commit_hw_done(old_state); 86 87 drm_atomic_helper_wait_for_flip_done(dev, old_state); 88 89 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) { 90 struct vkms_crtc_state *vkms_state = 91 to_vkms_crtc_state(old_crtc_state); 92 93 flush_work(&vkms_state->composer_work); 94 } 95 96 drm_atomic_helper_cleanup_planes(dev, old_state); 97 } 98 99 static struct drm_driver vkms_driver = { 100 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM, 101 .release = vkms_release, 102 .fops = &vkms_driver_fops, 103 .dumb_create = vkms_dumb_create, 104 .gem_vm_ops = &vkms_gem_vm_ops, 105 .gem_free_object_unlocked = vkms_gem_free_object, 106 .prime_fd_to_handle = drm_gem_prime_fd_to_handle, 107 .gem_prime_import_sg_table = vkms_prime_import_sg_table, 108 109 .name = DRIVER_NAME, 110 .desc = DRIVER_DESC, 111 .date = DRIVER_DATE, 112 .major = DRIVER_MAJOR, 113 .minor = DRIVER_MINOR, 114 }; 115 116 static const struct drm_mode_config_funcs vkms_mode_funcs = { 117 .fb_create = drm_gem_fb_create, 118 .atomic_check = drm_atomic_helper_check, 119 .atomic_commit = drm_atomic_helper_commit, 120 }; 121 122 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = { 123 .atomic_commit_tail = vkms_atomic_commit_tail, 124 }; 125 126 static int vkms_modeset_init(struct vkms_device *vkmsdev) 127 { 128 struct drm_device *dev = &vkmsdev->drm; 129 130 drm_mode_config_init(dev); 131 dev->mode_config.funcs = &vkms_mode_funcs; 132 dev->mode_config.min_width = XRES_MIN; 133 dev->mode_config.min_height = YRES_MIN; 134 dev->mode_config.max_width = XRES_MAX; 135 dev->mode_config.max_height = YRES_MAX; 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 } 141 142 static int __init vkms_init(void) 143 { 144 int ret; 145 146 vkms_device = kzalloc(sizeof(*vkms_device), GFP_KERNEL); 147 if (!vkms_device) 148 return -ENOMEM; 149 150 vkms_device->platform = 151 platform_device_register_simple(DRIVER_NAME, -1, NULL, 0); 152 if (IS_ERR(vkms_device->platform)) { 153 ret = PTR_ERR(vkms_device->platform); 154 goto out_free; 155 } 156 157 ret = drm_dev_init(&vkms_device->drm, &vkms_driver, 158 &vkms_device->platform->dev); 159 if (ret) 160 goto out_unregister; 161 162 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev, 163 DMA_BIT_MASK(64)); 164 165 if (ret) { 166 DRM_ERROR("Could not initialize DMA support\n"); 167 goto out_fini; 168 } 169 170 vkms_device->drm.irq_enabled = true; 171 172 ret = drm_vblank_init(&vkms_device->drm, 1); 173 if (ret) { 174 DRM_ERROR("Failed to vblank\n"); 175 goto out_fini; 176 } 177 178 ret = vkms_modeset_init(vkms_device); 179 if (ret) 180 goto out_fini; 181 182 ret = drm_dev_register(&vkms_device->drm, 0); 183 if (ret) 184 goto out_fini; 185 186 return 0; 187 188 out_fini: 189 drm_dev_fini(&vkms_device->drm); 190 191 out_unregister: 192 platform_device_unregister(vkms_device->platform); 193 194 out_free: 195 kfree(vkms_device); 196 return ret; 197 } 198 199 static void __exit vkms_exit(void) 200 { 201 if (!vkms_device) { 202 DRM_INFO("vkms_device is NULL.\n"); 203 return; 204 } 205 206 drm_dev_unregister(&vkms_device->drm); 207 drm_dev_put(&vkms_device->drm); 208 209 kfree(vkms_device); 210 } 211 212 module_init(vkms_init); 213 module_exit(vkms_exit); 214 215 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>"); 216 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>"); 217 MODULE_DESCRIPTION(DRIVER_DESC); 218 MODULE_LICENSE("GPL"); 219