1// SPDX-License-Identifier: GPL-2.0 or MIT
  2/*
  3 * Copyright 2018 Noralf Trønnes
  4 */
  5
  6#include <linux/iosys-map.h>
  7#include <linux/list.h>
  8#include <linux/mutex.h>
  9#include <linux/seq_file.h>
 10#include <linux/slab.h>
 11
 12#include <drm/drm_client.h>
 13#include <drm/drm_device.h>
 14#include <drm/drm_drv.h>
 15#include <drm/drm_file.h>
 16#include <drm/drm_fourcc.h>
 17#include <drm/drm_framebuffer.h>
 18#include <drm/drm_gem.h>
 19#include <drm/drm_mode.h>
 20#include <drm/drm_print.h>
 21
 22#include "drm_crtc_internal.h"
 23#include "drm_internal.h"
 24
 25/**
 26 * DOC: overview
 27 *
 28 * This library provides support for clients running in the kernel like fbdev and bootsplash.
 29 *
 30 * GEM drivers which provide a GEM based dumb buffer with a virtual address are supported.
 31 */
 32
 33static int drm_client_open(struct drm_client_dev *client)
 34{
 35	struct drm_device *dev = client->dev;
 36	struct drm_file *file;
 37
 38	file = drm_file_alloc(dev->primary);
 39	if (IS_ERR(file))
 40		return PTR_ERR(file);
 41
 42	mutex_lock(&dev->filelist_mutex);
 43	list_add(&file->lhead, &dev->filelist_internal);
 44	mutex_unlock(&dev->filelist_mutex);
 45
 46	client->file = file;
 47
 48	return 0;
 49}
 50
 51static void drm_client_close(struct drm_client_dev *client)
 52{
 53	struct drm_device *dev = client->dev;
 54
 55	mutex_lock(&dev->filelist_mutex);
 56	list_del(&client->file->lhead);
 57	mutex_unlock(&dev->filelist_mutex);
 58
 59	drm_file_free(client->file);
 60}
 61
 62/**
 63 * drm_client_init - Initialise a DRM client
 64 * @dev: DRM device
 65 * @client: DRM client
 66 * @name: Client name
 67 * @funcs: DRM client functions (optional)
 68 *
 69 * This initialises the client and opens a &drm_file.
 70 * Use drm_client_register() to complete the process.
 71 * The caller needs to hold a reference on @dev before calling this function.
 72 * The client is freed when the &drm_device is unregistered. See drm_client_release().
 73 *
 74 * Returns:
 75 * Zero on success or negative error code on failure.
 76 */
 77int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,
 78		    const char *name, const struct drm_client_funcs *funcs)
 79{
 80	int ret;
 81
 82	if (!drm_core_check_feature(dev, DRIVER_MODESET) || !dev->driver->dumb_create)
 83		return -EOPNOTSUPP;
 84
 85	client->dev = dev;
 86	client->name = name;
 87	client->funcs = funcs;
 88
 89	ret = drm_client_modeset_create(client);
 90	if (ret)
 91		return ret;
 92
 93	ret = drm_client_open(client);
 94	if (ret)
 95		goto err_free;
 96
 97	drm_dev_get(dev);
 98
 99	return 0;
100
101err_free:
102	drm_client_modeset_free(client);
103	return ret;
104}
105EXPORT_SYMBOL(drm_client_init);
106
107/**
108 * drm_client_register - Register client
109 * @client: DRM client
110 *
111 * Add the client to the &drm_device client list to activate its callbacks.
112 * @client must be initialized by a call to drm_client_init(). After
113 * drm_client_register() it is no longer permissible to call drm_client_release()
114 * directly (outside the unregister callback), instead cleanup will happen
115 * automatically on driver unload.
116 *
117 * Registering a client generates a hotplug event that allows the client
118 * to set up its display from pre-existing outputs. The client must have
119 * initialized its state to able to handle the hotplug event successfully.
120 */
121void drm_client_register(struct drm_client_dev *client)
122{
123	struct drm_device *dev = client->dev;
124	int ret;
125
126	mutex_lock(&dev->clientlist_mutex);
127	list_add(&client->list, &dev->clientlist);
128
129	if (client->funcs && client->funcs->hotplug) {
130		/*
131		 * Perform an initial hotplug event to pick up the
132		 * display configuration for the client. This step
133		 * has to be performed *after* registering the client
134		 * in the list of clients, or a concurrent hotplug
135		 * event might be lost; leaving the display off.
136		 *
137		 * Hold the clientlist_mutex as for a regular hotplug
138		 * event.
139		 */
140		ret = client->funcs->hotplug(client);
141		if (ret)
142			drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
143	}
144	mutex_unlock(&dev->clientlist_mutex);
145}
146EXPORT_SYMBOL(drm_client_register);
147
148/**
149 * drm_client_release - Release DRM client resources
150 * @client: DRM client
151 *
152 * Releases resources by closing the &drm_file that was opened by drm_client_init().
153 * It is called automatically if the &drm_client_funcs.unregister callback is _not_ set.
154 *
155 * This function should only be called from the unregister callback. An exception
156 * is fbdev which cannot free the buffer if userspace has open file descriptors.
157 *
158 * Note:
159 * Clients cannot initiate a release by themselves. This is done to keep the code simple.
160 * The driver has to be unloaded before the client can be unloaded.
161 */
162void drm_client_release(struct drm_client_dev *client)
163{
164	struct drm_device *dev = client->dev;
165
166	drm_dbg_kms(dev, "%s\n", client->name);
167
168	drm_client_modeset_free(client);
169	drm_client_close(client);
170	drm_dev_put(dev);
171}
172EXPORT_SYMBOL(drm_client_release);
173
174static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
175{
176	if (buffer->gem) {
177		drm_gem_vunmap_unlocked(buffer->gem, &buffer->map);
178		drm_gem_object_put(buffer->gem);
179	}
180
181	kfree(buffer);
182}
183
184static struct drm_client_buffer *
185drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height,
186			 u32 format, u32 *handle)
187{
188	const struct drm_format_info *info = drm_format_info(format);
189	struct drm_mode_create_dumb dumb_args = { };
190	struct drm_device *dev = client->dev;
191	struct drm_client_buffer *buffer;
192	struct drm_gem_object *obj;
193	int ret;
194
195	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
196	if (!buffer)
197		return ERR_PTR(-ENOMEM);
198
199	buffer->client = client;
200
201	dumb_args.width = width;
202	dumb_args.height = height;
203	dumb_args.bpp = drm_format_info_bpp(info, 0);
204	ret = drm_mode_create_dumb(dev, &dumb_args, client->file);
205	if (ret)
206		goto err_delete;
207
208	obj = drm_gem_object_lookup(client->file, dumb_args.handle);
209	if (!obj)  {
210		ret = -ENOENT;
211		goto err_delete;
212	}
213
214	buffer->pitch = dumb_args.pitch;
215	buffer->gem = obj;
216	*handle = dumb_args.handle;
217
218	return buffer;
219
220err_delete:
221	drm_client_buffer_delete(buffer);
222
223	return ERR_PTR(ret);
224}
225
226/**
227 * drm_client_buffer_vmap_local - Map DRM client buffer into address space
228 * @buffer: DRM client buffer
229 * @map_copy: Returns the mapped memory's address
230 *
231 * This function maps a client buffer into kernel address space. If the
232 * buffer is already mapped, it returns the existing mapping's address.
233 *
234 * Client buffer mappings are not ref'counted. Each call to
235 * drm_client_buffer_vmap_local() should be closely followed by a call to
236 * drm_client_buffer_vunmap_local(). See drm_client_buffer_vmap() for
237 * long-term mappings.
238 *
239 * The returned address is a copy of the internal value. In contrast to
240 * other vmap interfaces, you don't need it for the client's vunmap
241 * function. So you can modify it at will during blit and draw operations.
242 *
243 * Returns:
244 *	0 on success, or a negative errno code otherwise.
245 */
246int drm_client_buffer_vmap_local(struct drm_client_buffer *buffer,
247				 struct iosys_map *map_copy)
248{
249	struct drm_gem_object *gem = buffer->gem;
250	struct iosys_map *map = &buffer->map;
251	int ret;
252
253	drm_gem_lock(gem);
254
255	ret = drm_gem_vmap(gem, map);
256	if (ret)
257		goto err_drm_gem_vmap_unlocked;
258	*map_copy = *map;
259
260	return 0;
261
262err_drm_gem_vmap_unlocked:
263	drm_gem_unlock(gem);
264	return ret;
265}
266EXPORT_SYMBOL(drm_client_buffer_vmap_local);
267
268/**
269 * drm_client_buffer_vunmap_local - Unmap DRM client buffer
270 * @buffer: DRM client buffer
271 *
272 * This function removes a client buffer's memory mapping established
273 * with drm_client_buffer_vunmap_local(). Calling this function is only
274 * required by clients that manage their buffer mappings by themselves.
275 */
276void drm_client_buffer_vunmap_local(struct drm_client_buffer *buffer)
277{
278	struct drm_gem_object *gem = buffer->gem;
279	struct iosys_map *map = &buffer->map;
280
281	drm_gem_vunmap(gem, map);
282	drm_gem_unlock(gem);
283}
284EXPORT_SYMBOL(drm_client_buffer_vunmap_local);
285
286/**
287 * drm_client_buffer_vmap - Map DRM client buffer into address space
288 * @buffer: DRM client buffer
289 * @map_copy: Returns the mapped memory's address
290 *
291 * This function maps a client buffer into kernel address space. If the
292 * buffer is already mapped, it returns the existing mapping's address.
293 *
294 * Client buffer mappings are not ref'counted. Each call to
295 * drm_client_buffer_vmap() should be followed by a call to
296 * drm_client_buffer_vunmap(); or the client buffer should be mapped
297 * throughout its lifetime.
298 *
299 * The returned address is a copy of the internal value. In contrast to
300 * other vmap interfaces, you don't need it for the client's vunmap
301 * function. So you can modify it at will during blit and draw operations.
302 *
303 * Returns:
304 *	0 on success, or a negative errno code otherwise.
305 */
306int
307drm_client_buffer_vmap(struct drm_client_buffer *buffer,
308		       struct iosys_map *map_copy)
309{
310	struct drm_gem_object *gem = buffer->gem;
311	struct iosys_map *map = &buffer->map;
312	int ret;
313
314	drm_gem_lock(gem);
315
316	ret = drm_gem_pin_locked(gem);
317	if (ret)
318		goto err_drm_gem_pin_locked;
319	ret = drm_gem_vmap(gem, map);
320	if (ret)
321		goto err_drm_gem_vmap;
322
323	drm_gem_unlock(gem);
324
325	*map_copy = *map;
326
327	return 0;
328
329err_drm_gem_vmap:
330	drm_gem_unpin_locked(buffer->gem);
331err_drm_gem_pin_locked:
332	drm_gem_unlock(gem);
333	return ret;
334}
335EXPORT_SYMBOL(drm_client_buffer_vmap);
336
337/**
338 * drm_client_buffer_vunmap - Unmap DRM client buffer
339 * @buffer: DRM client buffer
340 *
341 * This function removes a client buffer's memory mapping. Calling this
342 * function is only required by clients that manage their buffer mappings
343 * by themselves.
344 */
345void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
346{
347	struct drm_gem_object *gem = buffer->gem;
348	struct iosys_map *map = &buffer->map;
349
350	drm_gem_lock(gem);
351	drm_gem_vunmap(gem, map);
352	drm_gem_unpin_locked(gem);
353	drm_gem_unlock(gem);
354}
355EXPORT_SYMBOL(drm_client_buffer_vunmap);
356
357static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
358{
359	int ret;
360
361	if (!buffer->fb)
362		return;
363
364	ret = drm_mode_rmfb(buffer->client->dev, buffer->fb->base.id, buffer->client->file);
365	if (ret)
366		drm_err(buffer->client->dev,
367			"Error removing FB:%u (%d)\n", buffer->fb->base.id, ret);
368
369	buffer->fb = NULL;
370}
371
372static int drm_client_buffer_addfb(struct drm_client_buffer *buffer,
373				   u32 width, u32 height, u32 format,
374				   u32 handle)
375{
376	struct drm_client_dev *client = buffer->client;
377	struct drm_mode_fb_cmd2 fb_req = { };
378	int ret;
379
380	fb_req.width = width;
381	fb_req.height = height;
382	fb_req.pixel_format = format;
383	fb_req.handles[0] = handle;
384	fb_req.pitches[0] = buffer->pitch;
385
386	ret = drm_mode_addfb2(client->dev, &fb_req, client->file);
387	if (ret)
388		return ret;
389
390	buffer->fb = drm_framebuffer_lookup(client->dev, buffer->client->file, fb_req.fb_id);
391	if (WARN_ON(!buffer->fb))
392		return -ENOENT;
393
394	/* drop the reference we picked up in framebuffer lookup */
395	drm_framebuffer_put(buffer->fb);
396
397	strscpy(buffer->fb->comm, client->name, TASK_COMM_LEN);
398
399	return 0;
400}
401
402/**
403 * drm_client_framebuffer_create - Create a client framebuffer
404 * @client: DRM client
405 * @width: Framebuffer width
406 * @height: Framebuffer height
407 * @format: Buffer format
408 *
409 * This function creates a &drm_client_buffer which consists of a
410 * &drm_framebuffer backed by a dumb buffer.
411 * Call drm_client_framebuffer_delete() to free the buffer.
412 *
413 * Returns:
414 * Pointer to a client buffer or an error pointer on failure.
415 */
416struct drm_client_buffer *
417drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format)
418{
419	struct drm_client_buffer *buffer;
420	u32 handle;
421	int ret;
422
423	buffer = drm_client_buffer_create(client, width, height, format,
424					  &handle);
425	if (IS_ERR(buffer))
426		return buffer;
427
428	ret = drm_client_buffer_addfb(buffer, width, height, format, handle);
429
430	/*
431	 * The handle is only needed for creating the framebuffer, destroy it
432	 * again to solve a circular dependency should anybody export the GEM
433	 * object as DMA-buf. The framebuffer and our buffer structure are still
434	 * holding references to the GEM object to prevent its destruction.
435	 */
436	drm_mode_destroy_dumb(client->dev, handle, client->file);
437
438	if (ret) {
439		drm_client_buffer_delete(buffer);
440		return ERR_PTR(ret);
441	}
442
443	return buffer;
444}
445EXPORT_SYMBOL(drm_client_framebuffer_create);
446
447/**
448 * drm_client_framebuffer_delete - Delete a client framebuffer
449 * @buffer: DRM client buffer (can be NULL)
450 */
451void drm_client_framebuffer_delete(struct drm_client_buffer *buffer)
452{
453	if (!buffer)
454		return;
455
456	drm_client_buffer_rmfb(buffer);
457	drm_client_buffer_delete(buffer);
458}
459EXPORT_SYMBOL(drm_client_framebuffer_delete);
460
461/**
462 * drm_client_framebuffer_flush - Manually flush client framebuffer
463 * @buffer: DRM client buffer (can be NULL)
464 * @rect: Damage rectangle (if NULL flushes all)
465 *
466 * This calls &drm_framebuffer_funcs->dirty (if present) to flush buffer changes
467 * for drivers that need it.
468 *
469 * Returns:
470 * Zero on success or negative error code on failure.
471 */
472int drm_client_framebuffer_flush(struct drm_client_buffer *buffer, struct drm_rect *rect)
473{
474	if (!buffer || !buffer->fb || !buffer->fb->funcs->dirty)
475		return 0;
476
477	if (rect) {
478		struct drm_clip_rect clip = {
479			.x1 = rect->x1,
480			.y1 = rect->y1,
481			.x2 = rect->x2,
482			.y2 = rect->y2,
483		};
484
485		return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
486						0, 0, &clip, 1);
487	}
488
489	return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
490					0, 0, NULL, 0);
491}
492EXPORT_SYMBOL(drm_client_framebuffer_flush);