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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * (C) COPYRIGHT 2016 ARM Limited. All rights reserved.
4 * Author: Brian Starkey <brian.starkey@arm.com>
5 *
6 * This program is free software and is provided to you under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation, and any use by you of this program is subject to the terms
9 * of such GNU licence.
10 */
11
12#include <linux/dma-fence.h>
13
14#include <drm/drm_crtc.h>
15#include <drm/drm_device.h>
16#include <drm/drm_drv.h>
17#include <drm/drm_framebuffer.h>
18#include <drm/drm_modeset_helper_vtables.h>
19#include <drm/drm_property.h>
20#include <drm/drm_writeback.h>
21
22/**
23 * DOC: overview
24 *
25 * Writeback connectors are used to expose hardware which can write the output
26 * from a CRTC to a memory buffer. They are used and act similarly to other
27 * types of connectors, with some important differences:
28 *
29 * * Writeback connectors don't provide a way to output visually to the user.
30 *
31 * * Writeback connectors are visible to userspace only when the client sets
32 * DRM_CLIENT_CAP_WRITEBACK_CONNECTORS.
33 *
34 * * Writeback connectors don't have EDID.
35 *
36 * A framebuffer may only be attached to a writeback connector when the
37 * connector is attached to a CRTC. The WRITEBACK_FB_ID property which sets the
38 * framebuffer applies only to a single commit (see below). A framebuffer may
39 * not be attached while the CRTC is off.
40 *
41 * Unlike with planes, when a writeback framebuffer is removed by userspace DRM
42 * makes no attempt to remove it from active use by the connector. This is
43 * because no method is provided to abort a writeback operation, and in any
44 * case making a new commit whilst a writeback is ongoing is undefined (see
45 * WRITEBACK_OUT_FENCE_PTR below). As soon as the current writeback is finished,
46 * the framebuffer will automatically no longer be in active use. As it will
47 * also have already been removed from the framebuffer list, there will be no
48 * way for any userspace application to retrieve a reference to it in the
49 * intervening period.
50 *
51 * Writeback connectors have some additional properties, which userspace
52 * can use to query and control them:
53 *
54 * "WRITEBACK_FB_ID":
55 * Write-only object property storing a DRM_MODE_OBJECT_FB: it stores the
56 * framebuffer to be written by the writeback connector. This property is
57 * similar to the FB_ID property on planes, but will always read as zero
58 * and is not preserved across commits.
59 * Userspace must set this property to an output buffer every time it
60 * wishes the buffer to get filled.
61 *
62 * "WRITEBACK_PIXEL_FORMATS":
63 * Immutable blob property to store the supported pixel formats table. The
64 * data is an array of u32 DRM_FORMAT_* fourcc values.
65 * Userspace can use this blob to find out what pixel formats are supported
66 * by the connector's writeback engine.
67 *
68 * "WRITEBACK_OUT_FENCE_PTR":
69 * Userspace can use this property to provide a pointer for the kernel to
70 * fill with a sync_file file descriptor, which will signal once the
71 * writeback is finished. The value should be the address of a 32-bit
72 * signed integer, cast to a u64.
73 * Userspace should wait for this fence to signal before making another
74 * commit affecting any of the same CRTCs, Planes or Connectors.
75 * **Failure to do so will result in undefined behaviour.**
76 * For this reason it is strongly recommended that all userspace
77 * applications making use of writeback connectors *always* retrieve an
78 * out-fence for the commit and use it appropriately.
79 * From userspace, this property will always read as zero.
80 */
81
82#define fence_to_wb_connector(x) container_of(x->lock, \
83 struct drm_writeback_connector, \
84 fence_lock)
85
86static const char *drm_writeback_fence_get_driver_name(struct dma_fence *fence)
87{
88 struct drm_writeback_connector *wb_connector =
89 fence_to_wb_connector(fence);
90
91 return wb_connector->base.dev->driver->name;
92}
93
94static const char *
95drm_writeback_fence_get_timeline_name(struct dma_fence *fence)
96{
97 struct drm_writeback_connector *wb_connector =
98 fence_to_wb_connector(fence);
99
100 return wb_connector->timeline_name;
101}
102
103static const struct dma_fence_ops drm_writeback_fence_ops = {
104 .get_driver_name = drm_writeback_fence_get_driver_name,
105 .get_timeline_name = drm_writeback_fence_get_timeline_name,
106};
107
108static int create_writeback_properties(struct drm_device *dev)
109{
110 struct drm_property *prop;
111
112 if (!dev->mode_config.writeback_fb_id_property) {
113 prop = drm_property_create_object(dev, DRM_MODE_PROP_ATOMIC,
114 "WRITEBACK_FB_ID",
115 DRM_MODE_OBJECT_FB);
116 if (!prop)
117 return -ENOMEM;
118 dev->mode_config.writeback_fb_id_property = prop;
119 }
120
121 if (!dev->mode_config.writeback_pixel_formats_property) {
122 prop = drm_property_create(dev, DRM_MODE_PROP_BLOB |
123 DRM_MODE_PROP_ATOMIC |
124 DRM_MODE_PROP_IMMUTABLE,
125 "WRITEBACK_PIXEL_FORMATS", 0);
126 if (!prop)
127 return -ENOMEM;
128 dev->mode_config.writeback_pixel_formats_property = prop;
129 }
130
131 if (!dev->mode_config.writeback_out_fence_ptr_property) {
132 prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
133 "WRITEBACK_OUT_FENCE_PTR", 0,
134 U64_MAX);
135 if (!prop)
136 return -ENOMEM;
137 dev->mode_config.writeback_out_fence_ptr_property = prop;
138 }
139
140 return 0;
141}
142
143static const struct drm_encoder_funcs drm_writeback_encoder_funcs = {
144 .destroy = drm_encoder_cleanup,
145};
146
147/**
148 * drm_writeback_connector_init - Initialize a writeback connector and its properties
149 * @dev: DRM device
150 * @wb_connector: Writeback connector to initialize
151 * @con_funcs: Connector funcs vtable
152 * @enc_helper_funcs: Encoder helper funcs vtable to be used by the internal encoder
153 * @formats: Array of supported pixel formats for the writeback engine
154 * @n_formats: Length of the formats array
155 * @possible_crtcs: possible crtcs for the internal writeback encoder
156 *
157 * This function creates the writeback-connector-specific properties if they
158 * have not been already created, initializes the connector as
159 * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property
160 * values. It will also create an internal encoder associated with the
161 * drm_writeback_connector and set it to use the @enc_helper_funcs vtable for
162 * the encoder helper.
163 *
164 * Drivers should always use this function instead of drm_connector_init() to
165 * set up writeback connectors.
166 *
167 * Returns: 0 on success, or a negative error code
168 */
169int drm_writeback_connector_init(struct drm_device *dev,
170 struct drm_writeback_connector *wb_connector,
171 const struct drm_connector_funcs *con_funcs,
172 const struct drm_encoder_helper_funcs *enc_helper_funcs,
173 const u32 *formats, int n_formats,
174 u32 possible_crtcs)
175{
176 int ret = 0;
177
178 drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs);
179
180 wb_connector->encoder.possible_crtcs = possible_crtcs;
181
182 ret = drm_encoder_init(dev, &wb_connector->encoder,
183 &drm_writeback_encoder_funcs,
184 DRM_MODE_ENCODER_VIRTUAL, NULL);
185 if (ret)
186 return ret;
187
188 ret = drm_writeback_connector_init_with_encoder(dev, wb_connector, &wb_connector->encoder,
189 con_funcs, formats, n_formats);
190
191 if (ret)
192 drm_encoder_cleanup(&wb_connector->encoder);
193
194 return ret;
195}
196EXPORT_SYMBOL(drm_writeback_connector_init);
197
198/**
199 * drm_writeback_connector_init_with_encoder - Initialize a writeback connector with
200 * a custom encoder
201 *
202 * @dev: DRM device
203 * @wb_connector: Writeback connector to initialize
204 * @enc: handle to the already initialized drm encoder
205 * @con_funcs: Connector funcs vtable
206 * @formats: Array of supported pixel formats for the writeback engine
207 * @n_formats: Length of the formats array
208 *
209 * This function creates the writeback-connector-specific properties if they
210 * have not been already created, initializes the connector as
211 * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property
212 * values.
213 *
214 * This function assumes that the drm_writeback_connector's encoder has already been
215 * created and initialized before invoking this function.
216 *
217 * In addition, this function also assumes that callers of this API will manage
218 * assigning the encoder helper functions, possible_crtcs and any other encoder
219 * specific operation.
220 *
221 * Drivers should always use this function instead of drm_connector_init() to
222 * set up writeback connectors if they want to manage themselves the lifetime of the
223 * associated encoder.
224 *
225 * Returns: 0 on success, or a negative error code
226 */
227int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
228 struct drm_writeback_connector *wb_connector, struct drm_encoder *enc,
229 const struct drm_connector_funcs *con_funcs, const u32 *formats,
230 int n_formats)
231{
232 struct drm_property_blob *blob;
233 struct drm_connector *connector = &wb_connector->base;
234 struct drm_mode_config *config = &dev->mode_config;
235 int ret = create_writeback_properties(dev);
236
237 if (ret != 0)
238 return ret;
239
240 blob = drm_property_create_blob(dev, n_formats * sizeof(*formats),
241 formats);
242 if (IS_ERR(blob))
243 return PTR_ERR(blob);
244
245
246 connector->interlace_allowed = 0;
247
248 ret = drm_connector_init(dev, connector, con_funcs,
249 DRM_MODE_CONNECTOR_WRITEBACK);
250 if (ret)
251 goto connector_fail;
252
253 ret = drm_connector_attach_encoder(connector, enc);
254 if (ret)
255 goto attach_fail;
256
257 INIT_LIST_HEAD(&wb_connector->job_queue);
258 spin_lock_init(&wb_connector->job_lock);
259
260 wb_connector->fence_context = dma_fence_context_alloc(1);
261 spin_lock_init(&wb_connector->fence_lock);
262 snprintf(wb_connector->timeline_name,
263 sizeof(wb_connector->timeline_name),
264 "CONNECTOR:%d-%s", connector->base.id, connector->name);
265
266 drm_object_attach_property(&connector->base,
267 config->writeback_out_fence_ptr_property, 0);
268
269 drm_object_attach_property(&connector->base,
270 config->writeback_fb_id_property, 0);
271
272 drm_object_attach_property(&connector->base,
273 config->writeback_pixel_formats_property,
274 blob->base.id);
275 wb_connector->pixel_formats_blob_ptr = blob;
276
277 return 0;
278
279attach_fail:
280 drm_connector_cleanup(connector);
281connector_fail:
282 drm_property_blob_put(blob);
283 return ret;
284}
285EXPORT_SYMBOL(drm_writeback_connector_init_with_encoder);
286
287int drm_writeback_set_fb(struct drm_connector_state *conn_state,
288 struct drm_framebuffer *fb)
289{
290 WARN_ON(conn_state->connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK);
291
292 if (!conn_state->writeback_job) {
293 conn_state->writeback_job =
294 kzalloc(sizeof(*conn_state->writeback_job), GFP_KERNEL);
295 if (!conn_state->writeback_job)
296 return -ENOMEM;
297
298 conn_state->writeback_job->connector =
299 drm_connector_to_writeback(conn_state->connector);
300 }
301
302 drm_framebuffer_assign(&conn_state->writeback_job->fb, fb);
303 return 0;
304}
305
306int drm_writeback_prepare_job(struct drm_writeback_job *job)
307{
308 struct drm_writeback_connector *connector = job->connector;
309 const struct drm_connector_helper_funcs *funcs =
310 connector->base.helper_private;
311 int ret;
312
313 if (funcs->prepare_writeback_job) {
314 ret = funcs->prepare_writeback_job(connector, job);
315 if (ret < 0)
316 return ret;
317 }
318
319 job->prepared = true;
320 return 0;
321}
322EXPORT_SYMBOL(drm_writeback_prepare_job);
323
324/**
325 * drm_writeback_queue_job - Queue a writeback job for later signalling
326 * @wb_connector: The writeback connector to queue a job on
327 * @conn_state: The connector state containing the job to queue
328 *
329 * This function adds the job contained in @conn_state to the job_queue for a
330 * writeback connector. It takes ownership of the writeback job and sets the
331 * @conn_state->writeback_job to NULL, and so no access to the job may be
332 * performed by the caller after this function returns.
333 *
334 * Drivers must ensure that for a given writeback connector, jobs are queued in
335 * exactly the same order as they will be completed by the hardware (and
336 * signaled via drm_writeback_signal_completion).
337 *
338 * For every call to drm_writeback_queue_job() there must be exactly one call to
339 * drm_writeback_signal_completion()
340 *
341 * See also: drm_writeback_signal_completion()
342 */
343void drm_writeback_queue_job(struct drm_writeback_connector *wb_connector,
344 struct drm_connector_state *conn_state)
345{
346 struct drm_writeback_job *job;
347 unsigned long flags;
348
349 job = conn_state->writeback_job;
350 conn_state->writeback_job = NULL;
351
352 spin_lock_irqsave(&wb_connector->job_lock, flags);
353 list_add_tail(&job->list_entry, &wb_connector->job_queue);
354 spin_unlock_irqrestore(&wb_connector->job_lock, flags);
355}
356EXPORT_SYMBOL(drm_writeback_queue_job);
357
358void drm_writeback_cleanup_job(struct drm_writeback_job *job)
359{
360 struct drm_writeback_connector *connector = job->connector;
361 const struct drm_connector_helper_funcs *funcs =
362 connector->base.helper_private;
363
364 if (job->prepared && funcs->cleanup_writeback_job)
365 funcs->cleanup_writeback_job(connector, job);
366
367 if (job->fb)
368 drm_framebuffer_put(job->fb);
369
370 if (job->out_fence)
371 dma_fence_put(job->out_fence);
372
373 kfree(job);
374}
375EXPORT_SYMBOL(drm_writeback_cleanup_job);
376
377/*
378 * @cleanup_work: deferred cleanup of a writeback job
379 *
380 * The job cannot be cleaned up directly in drm_writeback_signal_completion,
381 * because it may be called in interrupt context. Dropping the framebuffer
382 * reference can sleep, and so the cleanup is deferred to a workqueue.
383 */
384static void cleanup_work(struct work_struct *work)
385{
386 struct drm_writeback_job *job = container_of(work,
387 struct drm_writeback_job,
388 cleanup_work);
389
390 drm_writeback_cleanup_job(job);
391}
392
393/**
394 * drm_writeback_signal_completion - Signal the completion of a writeback job
395 * @wb_connector: The writeback connector whose job is complete
396 * @status: Status code to set in the writeback out_fence (0 for success)
397 *
398 * Drivers should call this to signal the completion of a previously queued
399 * writeback job. It should be called as soon as possible after the hardware
400 * has finished writing, and may be called from interrupt context.
401 * It is the driver's responsibility to ensure that for a given connector, the
402 * hardware completes writeback jobs in the same order as they are queued.
403 *
404 * Unless the driver is holding its own reference to the framebuffer, it must
405 * not be accessed after calling this function.
406 *
407 * See also: drm_writeback_queue_job()
408 */
409void
410drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector,
411 int status)
412{
413 unsigned long flags;
414 struct drm_writeback_job *job;
415 struct dma_fence *out_fence;
416
417 spin_lock_irqsave(&wb_connector->job_lock, flags);
418 job = list_first_entry_or_null(&wb_connector->job_queue,
419 struct drm_writeback_job,
420 list_entry);
421 if (job)
422 list_del(&job->list_entry);
423
424 spin_unlock_irqrestore(&wb_connector->job_lock, flags);
425
426 if (WARN_ON(!job))
427 return;
428
429 out_fence = job->out_fence;
430 if (out_fence) {
431 if (status)
432 dma_fence_set_error(out_fence, status);
433 dma_fence_signal(out_fence);
434 dma_fence_put(out_fence);
435 job->out_fence = NULL;
436 }
437
438 INIT_WORK(&job->cleanup_work, cleanup_work);
439 queue_work(system_long_wq, &job->cleanup_work);
440}
441EXPORT_SYMBOL(drm_writeback_signal_completion);
442
443struct dma_fence *
444drm_writeback_get_out_fence(struct drm_writeback_connector *wb_connector)
445{
446 struct dma_fence *fence;
447
448 if (WARN_ON(wb_connector->base.connector_type !=
449 DRM_MODE_CONNECTOR_WRITEBACK))
450 return NULL;
451
452 fence = kzalloc(sizeof(*fence), GFP_KERNEL);
453 if (!fence)
454 return NULL;
455
456 dma_fence_init(fence, &drm_writeback_fence_ops,
457 &wb_connector->fence_lock, wb_connector->fence_context,
458 ++wb_connector->fence_seqno);
459
460 return fence;
461}
462EXPORT_SYMBOL(drm_writeback_get_out_fence);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * (C) COPYRIGHT 2016 ARM Limited. All rights reserved.
4 * Author: Brian Starkey <brian.starkey@arm.com>
5 *
6 * This program is free software and is provided to you under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation, and any use by you of this program is subject to the terms
9 * of such GNU licence.
10 */
11
12#include <linux/dma-fence.h>
13
14#include <drm/drm_crtc.h>
15#include <drm/drm_device.h>
16#include <drm/drm_drv.h>
17#include <drm/drm_modeset_helper_vtables.h>
18#include <drm/drm_property.h>
19#include <drm/drm_writeback.h>
20
21/**
22 * DOC: overview
23 *
24 * Writeback connectors are used to expose hardware which can write the output
25 * from a CRTC to a memory buffer. They are used and act similarly to other
26 * types of connectors, with some important differences:
27 *
28 * * Writeback connectors don't provide a way to output visually to the user.
29 *
30 * * Writeback connectors are visible to userspace only when the client sets
31 * DRM_CLIENT_CAP_WRITEBACK_CONNECTORS.
32 *
33 * * Writeback connectors don't have EDID.
34 *
35 * A framebuffer may only be attached to a writeback connector when the
36 * connector is attached to a CRTC. The WRITEBACK_FB_ID property which sets the
37 * framebuffer applies only to a single commit (see below). A framebuffer may
38 * not be attached while the CRTC is off.
39 *
40 * Unlike with planes, when a writeback framebuffer is removed by userspace DRM
41 * makes no attempt to remove it from active use by the connector. This is
42 * because no method is provided to abort a writeback operation, and in any
43 * case making a new commit whilst a writeback is ongoing is undefined (see
44 * WRITEBACK_OUT_FENCE_PTR below). As soon as the current writeback is finished,
45 * the framebuffer will automatically no longer be in active use. As it will
46 * also have already been removed from the framebuffer list, there will be no
47 * way for any userspace application to retrieve a reference to it in the
48 * intervening period.
49 *
50 * Writeback connectors have some additional properties, which userspace
51 * can use to query and control them:
52 *
53 * "WRITEBACK_FB_ID":
54 * Write-only object property storing a DRM_MODE_OBJECT_FB: it stores the
55 * framebuffer to be written by the writeback connector. This property is
56 * similar to the FB_ID property on planes, but will always read as zero
57 * and is not preserved across commits.
58 * Userspace must set this property to an output buffer every time it
59 * wishes the buffer to get filled.
60 *
61 * "WRITEBACK_PIXEL_FORMATS":
62 * Immutable blob property to store the supported pixel formats table. The
63 * data is an array of u32 DRM_FORMAT_* fourcc values.
64 * Userspace can use this blob to find out what pixel formats are supported
65 * by the connector's writeback engine.
66 *
67 * "WRITEBACK_OUT_FENCE_PTR":
68 * Userspace can use this property to provide a pointer for the kernel to
69 * fill with a sync_file file descriptor, which will signal once the
70 * writeback is finished. The value should be the address of a 32-bit
71 * signed integer, cast to a u64.
72 * Userspace should wait for this fence to signal before making another
73 * commit affecting any of the same CRTCs, Planes or Connectors.
74 * **Failure to do so will result in undefined behaviour.**
75 * For this reason it is strongly recommended that all userspace
76 * applications making use of writeback connectors *always* retrieve an
77 * out-fence for the commit and use it appropriately.
78 * From userspace, this property will always read as zero.
79 */
80
81#define fence_to_wb_connector(x) container_of(x->lock, \
82 struct drm_writeback_connector, \
83 fence_lock)
84
85static const char *drm_writeback_fence_get_driver_name(struct dma_fence *fence)
86{
87 struct drm_writeback_connector *wb_connector =
88 fence_to_wb_connector(fence);
89
90 return wb_connector->base.dev->driver->name;
91}
92
93static const char *
94drm_writeback_fence_get_timeline_name(struct dma_fence *fence)
95{
96 struct drm_writeback_connector *wb_connector =
97 fence_to_wb_connector(fence);
98
99 return wb_connector->timeline_name;
100}
101
102static bool drm_writeback_fence_enable_signaling(struct dma_fence *fence)
103{
104 return true;
105}
106
107static const struct dma_fence_ops drm_writeback_fence_ops = {
108 .get_driver_name = drm_writeback_fence_get_driver_name,
109 .get_timeline_name = drm_writeback_fence_get_timeline_name,
110 .enable_signaling = drm_writeback_fence_enable_signaling,
111};
112
113static int create_writeback_properties(struct drm_device *dev)
114{
115 struct drm_property *prop;
116
117 if (!dev->mode_config.writeback_fb_id_property) {
118 prop = drm_property_create_object(dev, DRM_MODE_PROP_ATOMIC,
119 "WRITEBACK_FB_ID",
120 DRM_MODE_OBJECT_FB);
121 if (!prop)
122 return -ENOMEM;
123 dev->mode_config.writeback_fb_id_property = prop;
124 }
125
126 if (!dev->mode_config.writeback_pixel_formats_property) {
127 prop = drm_property_create(dev, DRM_MODE_PROP_BLOB |
128 DRM_MODE_PROP_ATOMIC |
129 DRM_MODE_PROP_IMMUTABLE,
130 "WRITEBACK_PIXEL_FORMATS", 0);
131 if (!prop)
132 return -ENOMEM;
133 dev->mode_config.writeback_pixel_formats_property = prop;
134 }
135
136 if (!dev->mode_config.writeback_out_fence_ptr_property) {
137 prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
138 "WRITEBACK_OUT_FENCE_PTR", 0,
139 U64_MAX);
140 if (!prop)
141 return -ENOMEM;
142 dev->mode_config.writeback_out_fence_ptr_property = prop;
143 }
144
145 return 0;
146}
147
148static const struct drm_encoder_funcs drm_writeback_encoder_funcs = {
149 .destroy = drm_encoder_cleanup,
150};
151
152/**
153 * drm_writeback_connector_init - Initialize a writeback connector and its properties
154 * @dev: DRM device
155 * @wb_connector: Writeback connector to initialize
156 * @con_funcs: Connector funcs vtable
157 * @enc_helper_funcs: Encoder helper funcs vtable to be used by the internal encoder
158 * @formats: Array of supported pixel formats for the writeback engine
159 * @n_formats: Length of the formats array
160 *
161 * This function creates the writeback-connector-specific properties if they
162 * have not been already created, initializes the connector as
163 * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property
164 * values. It will also create an internal encoder associated with the
165 * drm_writeback_connector and set it to use the @enc_helper_funcs vtable for
166 * the encoder helper.
167 *
168 * Drivers should always use this function instead of drm_connector_init() to
169 * set up writeback connectors.
170 *
171 * Returns: 0 on success, or a negative error code
172 */
173int drm_writeback_connector_init(struct drm_device *dev,
174 struct drm_writeback_connector *wb_connector,
175 const struct drm_connector_funcs *con_funcs,
176 const struct drm_encoder_helper_funcs *enc_helper_funcs,
177 const u32 *formats, int n_formats)
178{
179 struct drm_property_blob *blob;
180 struct drm_connector *connector = &wb_connector->base;
181 struct drm_mode_config *config = &dev->mode_config;
182 int ret = create_writeback_properties(dev);
183
184 if (ret != 0)
185 return ret;
186
187 blob = drm_property_create_blob(dev, n_formats * sizeof(*formats),
188 formats);
189 if (IS_ERR(blob))
190 return PTR_ERR(blob);
191
192 drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs);
193 ret = drm_encoder_init(dev, &wb_connector->encoder,
194 &drm_writeback_encoder_funcs,
195 DRM_MODE_ENCODER_VIRTUAL, NULL);
196 if (ret)
197 goto fail;
198
199 connector->interlace_allowed = 0;
200
201 ret = drm_connector_init(dev, connector, con_funcs,
202 DRM_MODE_CONNECTOR_WRITEBACK);
203 if (ret)
204 goto connector_fail;
205
206 ret = drm_connector_attach_encoder(connector,
207 &wb_connector->encoder);
208 if (ret)
209 goto attach_fail;
210
211 INIT_LIST_HEAD(&wb_connector->job_queue);
212 spin_lock_init(&wb_connector->job_lock);
213
214 wb_connector->fence_context = dma_fence_context_alloc(1);
215 spin_lock_init(&wb_connector->fence_lock);
216 snprintf(wb_connector->timeline_name,
217 sizeof(wb_connector->timeline_name),
218 "CONNECTOR:%d-%s", connector->base.id, connector->name);
219
220 drm_object_attach_property(&connector->base,
221 config->writeback_out_fence_ptr_property, 0);
222
223 drm_object_attach_property(&connector->base,
224 config->writeback_fb_id_property, 0);
225
226 drm_object_attach_property(&connector->base,
227 config->writeback_pixel_formats_property,
228 blob->base.id);
229 wb_connector->pixel_formats_blob_ptr = blob;
230
231 return 0;
232
233attach_fail:
234 drm_connector_cleanup(connector);
235connector_fail:
236 drm_encoder_cleanup(&wb_connector->encoder);
237fail:
238 drm_property_blob_put(blob);
239 return ret;
240}
241EXPORT_SYMBOL(drm_writeback_connector_init);
242
243int drm_writeback_set_fb(struct drm_connector_state *conn_state,
244 struct drm_framebuffer *fb)
245{
246 WARN_ON(conn_state->connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK);
247
248 if (!conn_state->writeback_job) {
249 conn_state->writeback_job =
250 kzalloc(sizeof(*conn_state->writeback_job), GFP_KERNEL);
251 if (!conn_state->writeback_job)
252 return -ENOMEM;
253
254 conn_state->writeback_job->connector =
255 drm_connector_to_writeback(conn_state->connector);
256 }
257
258 drm_framebuffer_assign(&conn_state->writeback_job->fb, fb);
259 return 0;
260}
261
262int drm_writeback_prepare_job(struct drm_writeback_job *job)
263{
264 struct drm_writeback_connector *connector = job->connector;
265 const struct drm_connector_helper_funcs *funcs =
266 connector->base.helper_private;
267 int ret;
268
269 if (funcs->prepare_writeback_job) {
270 ret = funcs->prepare_writeback_job(connector, job);
271 if (ret < 0)
272 return ret;
273 }
274
275 job->prepared = true;
276 return 0;
277}
278EXPORT_SYMBOL(drm_writeback_prepare_job);
279
280/**
281 * drm_writeback_queue_job - Queue a writeback job for later signalling
282 * @wb_connector: The writeback connector to queue a job on
283 * @conn_state: The connector state containing the job to queue
284 *
285 * This function adds the job contained in @conn_state to the job_queue for a
286 * writeback connector. It takes ownership of the writeback job and sets the
287 * @conn_state->writeback_job to NULL, and so no access to the job may be
288 * performed by the caller after this function returns.
289 *
290 * Drivers must ensure that for a given writeback connector, jobs are queued in
291 * exactly the same order as they will be completed by the hardware (and
292 * signaled via drm_writeback_signal_completion).
293 *
294 * For every call to drm_writeback_queue_job() there must be exactly one call to
295 * drm_writeback_signal_completion()
296 *
297 * See also: drm_writeback_signal_completion()
298 */
299void drm_writeback_queue_job(struct drm_writeback_connector *wb_connector,
300 struct drm_connector_state *conn_state)
301{
302 struct drm_writeback_job *job;
303 unsigned long flags;
304
305 job = conn_state->writeback_job;
306 conn_state->writeback_job = NULL;
307
308 spin_lock_irqsave(&wb_connector->job_lock, flags);
309 list_add_tail(&job->list_entry, &wb_connector->job_queue);
310 spin_unlock_irqrestore(&wb_connector->job_lock, flags);
311}
312EXPORT_SYMBOL(drm_writeback_queue_job);
313
314void drm_writeback_cleanup_job(struct drm_writeback_job *job)
315{
316 struct drm_writeback_connector *connector = job->connector;
317 const struct drm_connector_helper_funcs *funcs =
318 connector->base.helper_private;
319
320 if (job->prepared && funcs->cleanup_writeback_job)
321 funcs->cleanup_writeback_job(connector, job);
322
323 if (job->fb)
324 drm_framebuffer_put(job->fb);
325
326 if (job->out_fence)
327 dma_fence_put(job->out_fence);
328
329 kfree(job);
330}
331EXPORT_SYMBOL(drm_writeback_cleanup_job);
332
333/*
334 * @cleanup_work: deferred cleanup of a writeback job
335 *
336 * The job cannot be cleaned up directly in drm_writeback_signal_completion,
337 * because it may be called in interrupt context. Dropping the framebuffer
338 * reference can sleep, and so the cleanup is deferred to a workqueue.
339 */
340static void cleanup_work(struct work_struct *work)
341{
342 struct drm_writeback_job *job = container_of(work,
343 struct drm_writeback_job,
344 cleanup_work);
345
346 drm_writeback_cleanup_job(job);
347}
348
349/**
350 * drm_writeback_signal_completion - Signal the completion of a writeback job
351 * @wb_connector: The writeback connector whose job is complete
352 * @status: Status code to set in the writeback out_fence (0 for success)
353 *
354 * Drivers should call this to signal the completion of a previously queued
355 * writeback job. It should be called as soon as possible after the hardware
356 * has finished writing, and may be called from interrupt context.
357 * It is the driver's responsibility to ensure that for a given connector, the
358 * hardware completes writeback jobs in the same order as they are queued.
359 *
360 * Unless the driver is holding its own reference to the framebuffer, it must
361 * not be accessed after calling this function.
362 *
363 * See also: drm_writeback_queue_job()
364 */
365void
366drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector,
367 int status)
368{
369 unsigned long flags;
370 struct drm_writeback_job *job;
371 struct dma_fence *out_fence;
372
373 spin_lock_irqsave(&wb_connector->job_lock, flags);
374 job = list_first_entry_or_null(&wb_connector->job_queue,
375 struct drm_writeback_job,
376 list_entry);
377 if (job)
378 list_del(&job->list_entry);
379
380 spin_unlock_irqrestore(&wb_connector->job_lock, flags);
381
382 if (WARN_ON(!job))
383 return;
384
385 out_fence = job->out_fence;
386 if (out_fence) {
387 if (status)
388 dma_fence_set_error(out_fence, status);
389 dma_fence_signal(out_fence);
390 dma_fence_put(out_fence);
391 job->out_fence = NULL;
392 }
393
394 INIT_WORK(&job->cleanup_work, cleanup_work);
395 queue_work(system_long_wq, &job->cleanup_work);
396}
397EXPORT_SYMBOL(drm_writeback_signal_completion);
398
399struct dma_fence *
400drm_writeback_get_out_fence(struct drm_writeback_connector *wb_connector)
401{
402 struct dma_fence *fence;
403
404 if (WARN_ON(wb_connector->base.connector_type !=
405 DRM_MODE_CONNECTOR_WRITEBACK))
406 return NULL;
407
408 fence = kzalloc(sizeof(*fence), GFP_KERNEL);
409 if (!fence)
410 return NULL;
411
412 dma_fence_init(fence, &drm_writeback_fence_ops,
413 &wb_connector->fence_lock, wb_connector->fence_context,
414 ++wb_connector->fence_seqno);
415
416 return fence;
417}
418EXPORT_SYMBOL(drm_writeback_get_out_fence);