1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright 2018 Noralf Trønnes
6 #include <linux/list.h>
7 #include <linux/module.h>
8 #include <linux/mutex.h>
9 #include <linux/seq_file.h>
10 #include <linux/slab.h>
12 #include <drm/drm_client.h>
13 #include <drm/drm_debugfs.h>
14 #include <drm/drm_device.h>
15 #include <drm/drm_drv.h>
16 #include <drm/drm_file.h>
17 #include <drm/drm_fourcc.h>
18 #include <drm/drm_gem.h>
19 #include <drm/drm_mode.h>
20 #include <drm/drm_print.h>
23 #include "drm_crtc_internal.h"
24 #include "drm_internal.h"
29 * This library provides support for clients running in the kernel like fbdev and bootsplash.
30 * Currently it's only partially implemented, just enough to support fbdev.
32 * GEM drivers which provide a GEM based dumb buffer with a virtual address are supported.
35 static int drm_client_open(struct drm_client_dev *client)
37 struct drm_device *dev = client->dev;
38 struct drm_file *file;
40 file = drm_file_alloc(dev->primary);
44 mutex_lock(&dev->filelist_mutex);
45 list_add(&file->lhead, &dev->filelist_internal);
46 mutex_unlock(&dev->filelist_mutex);
53 static void drm_client_close(struct drm_client_dev *client)
55 struct drm_device *dev = client->dev;
57 mutex_lock(&dev->filelist_mutex);
58 list_del(&client->file->lhead);
59 mutex_unlock(&dev->filelist_mutex);
61 drm_file_free(client->file);
63 EXPORT_SYMBOL(drm_client_close);
66 * drm_client_new - Create a DRM client
70 * @funcs: DRM client functions (optional)
72 * The caller needs to hold a reference on @dev before calling this function.
73 * The client is freed when the &drm_device is unregistered. See drm_client_release().
76 * Zero on success or negative error code on failure.
78 int drm_client_new(struct drm_device *dev, struct drm_client_dev *client,
79 const char *name, const struct drm_client_funcs *funcs)
83 if (!drm_core_check_feature(dev, DRIVER_MODESET) ||
84 !dev->driver->dumb_create || !dev->driver->gem_prime_vmap)
87 if (funcs && !try_module_get(funcs->owner))
92 client->funcs = funcs;
94 ret = drm_client_open(client);
98 mutex_lock(&dev->clientlist_mutex);
99 list_add(&client->list, &dev->clientlist);
100 mutex_unlock(&dev->clientlist_mutex);
108 module_put(funcs->owner);
112 EXPORT_SYMBOL(drm_client_new);
115 * drm_client_release - Release DRM client resources
116 * @client: DRM client
118 * Releases resources by closing the &drm_file that was opened by drm_client_new().
119 * It is called automatically if the &drm_client_funcs.unregister callback is _not_ set.
121 * This function should only be called from the unregister callback. An exception
122 * is fbdev which cannot free the buffer if userspace has open file descriptors.
125 * Clients cannot initiate a release by themselves. This is done to keep the code simple.
126 * The driver has to be unloaded before the client can be unloaded.
128 void drm_client_release(struct drm_client_dev *client)
130 struct drm_device *dev = client->dev;
132 DRM_DEV_DEBUG_KMS(dev->dev, "%s\n", client->name);
134 drm_client_close(client);
137 module_put(client->funcs->owner);
139 EXPORT_SYMBOL(drm_client_release);
141 void drm_client_dev_unregister(struct drm_device *dev)
143 struct drm_client_dev *client, *tmp;
145 if (!drm_core_check_feature(dev, DRIVER_MODESET))
148 mutex_lock(&dev->clientlist_mutex);
149 list_for_each_entry_safe(client, tmp, &dev->clientlist, list) {
150 list_del(&client->list);
151 if (client->funcs && client->funcs->unregister) {
152 client->funcs->unregister(client);
154 drm_client_release(client);
158 mutex_unlock(&dev->clientlist_mutex);
162 * drm_client_dev_hotplug - Send hotplug event to clients
165 * This function calls the &drm_client_funcs.hotplug callback on the attached clients.
167 * drm_kms_helper_hotplug_event() calls this function, so drivers that use it
168 * don't need to call this function themselves.
170 void drm_client_dev_hotplug(struct drm_device *dev)
172 struct drm_client_dev *client;
175 if (!drm_core_check_feature(dev, DRIVER_MODESET))
178 mutex_lock(&dev->clientlist_mutex);
179 list_for_each_entry(client, &dev->clientlist, list) {
180 if (!client->funcs || !client->funcs->hotplug)
183 ret = client->funcs->hotplug(client);
184 DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->name, ret);
186 mutex_unlock(&dev->clientlist_mutex);
188 EXPORT_SYMBOL(drm_client_dev_hotplug);
190 void drm_client_dev_restore(struct drm_device *dev)
192 struct drm_client_dev *client;
195 if (!drm_core_check_feature(dev, DRIVER_MODESET))
198 mutex_lock(&dev->clientlist_mutex);
199 list_for_each_entry(client, &dev->clientlist, list) {
200 if (!client->funcs || !client->funcs->restore)
203 ret = client->funcs->restore(client);
204 DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->name, ret);
205 if (!ret) /* The first one to return zero gets the privilege to restore */
208 mutex_unlock(&dev->clientlist_mutex);
211 static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
213 struct drm_device *dev = buffer->client->dev;
215 if (buffer->vaddr && dev->driver->gem_prime_vunmap)
216 dev->driver->gem_prime_vunmap(buffer->gem, buffer->vaddr);
219 drm_gem_object_put_unlocked(buffer->gem);
222 drm_mode_destroy_dumb(dev, buffer->handle, buffer->client->file);
227 static struct drm_client_buffer *
228 drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format)
230 struct drm_mode_create_dumb dumb_args = { };
231 struct drm_device *dev = client->dev;
232 struct drm_client_buffer *buffer;
233 struct drm_gem_object *obj;
237 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
239 return ERR_PTR(-ENOMEM);
241 buffer->client = client;
243 dumb_args.width = width;
244 dumb_args.height = height;
245 dumb_args.bpp = drm_format_plane_cpp(format, 0) * 8;
246 ret = drm_mode_create_dumb(dev, &dumb_args, client->file);
250 buffer->handle = dumb_args.handle;
251 buffer->pitch = dumb_args.pitch;
253 obj = drm_gem_object_lookup(client->file, dumb_args.handle);
262 * FIXME: The dependency on GEM here isn't required, we could
263 * convert the driver handle to a dma-buf instead and use the
264 * backend-agnostic dma-buf vmap support instead. This would
265 * require that the handle2fd prime ioctl is reworked to pull the
266 * fd_install step out of the driver backend hooks, to make that
267 * final step optional for internal users.
269 vaddr = dev->driver->gem_prime_vmap(obj);
275 buffer->vaddr = vaddr;
280 drm_client_buffer_delete(buffer);
285 static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
292 ret = drm_mode_rmfb(buffer->client->dev, buffer->fb->base.id, buffer->client->file);
294 DRM_DEV_ERROR(buffer->client->dev->dev,
295 "Error removing FB:%u (%d)\n", buffer->fb->base.id, ret);
300 static int drm_client_buffer_addfb(struct drm_client_buffer *buffer,
301 u32 width, u32 height, u32 format)
303 struct drm_client_dev *client = buffer->client;
304 struct drm_mode_fb_cmd fb_req = { };
305 const struct drm_format_info *info;
308 info = drm_format_info(format);
309 fb_req.bpp = info->cpp[0] * 8;
310 fb_req.depth = info->depth;
311 fb_req.width = width;
312 fb_req.height = height;
313 fb_req.handle = buffer->handle;
314 fb_req.pitch = buffer->pitch;
316 ret = drm_mode_addfb(client->dev, &fb_req, client->file);
320 buffer->fb = drm_framebuffer_lookup(client->dev, buffer->client->file, fb_req.fb_id);
321 if (WARN_ON(!buffer->fb))
324 /* drop the reference we picked up in framebuffer lookup */
325 drm_framebuffer_put(buffer->fb);
327 strscpy(buffer->fb->comm, client->name, TASK_COMM_LEN);
333 * drm_client_framebuffer_create - Create a client framebuffer
334 * @client: DRM client
335 * @width: Framebuffer width
336 * @height: Framebuffer height
337 * @format: Buffer format
339 * This function creates a &drm_client_buffer which consists of a
340 * &drm_framebuffer backed by a dumb buffer.
341 * Call drm_client_framebuffer_delete() to free the buffer.
344 * Pointer to a client buffer or an error pointer on failure.
346 struct drm_client_buffer *
347 drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format)
349 struct drm_client_buffer *buffer;
352 buffer = drm_client_buffer_create(client, width, height, format);
356 ret = drm_client_buffer_addfb(buffer, width, height, format);
358 drm_client_buffer_delete(buffer);
364 EXPORT_SYMBOL(drm_client_framebuffer_create);
367 * drm_client_framebuffer_delete - Delete a client framebuffer
368 * @buffer: DRM client buffer (can be NULL)
370 void drm_client_framebuffer_delete(struct drm_client_buffer *buffer)
375 drm_client_buffer_rmfb(buffer);
376 drm_client_buffer_delete(buffer);
378 EXPORT_SYMBOL(drm_client_framebuffer_delete);
380 #ifdef CONFIG_DEBUG_FS
381 static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data)
383 struct drm_info_node *node = m->private;
384 struct drm_device *dev = node->minor->dev;
385 struct drm_printer p = drm_seq_file_printer(m);
386 struct drm_client_dev *client;
388 mutex_lock(&dev->clientlist_mutex);
389 list_for_each_entry(client, &dev->clientlist, list)
390 drm_printf(&p, "%s\n", client->name);
391 mutex_unlock(&dev->clientlist_mutex);
396 static const struct drm_info_list drm_client_debugfs_list[] = {
397 { "internal_clients", drm_client_debugfs_internal_clients, 0 },
400 int drm_client_debugfs_init(struct drm_minor *minor)
402 return drm_debugfs_create_files(drm_client_debugfs_list,
403 ARRAY_SIZE(drm_client_debugfs_list),
404 minor->debugfs_root, minor);