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1/*
2 * Copyright © 2008 Intel Corporation
3 * Copyright © 2016 Collabora Ltd
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22 * IN THE SOFTWARE.
23 *
24 * Based on code from the i915 driver.
25 * Original author: Damien Lespiau <damien.lespiau@intel.com>
26 *
27 */
28
29#include <linux/circ_buf.h>
30#include <linux/ctype.h>
31#include <linux/debugfs.h>
32#include <linux/poll.h>
33#include <linux/uaccess.h>
34
35#include <drm/drm_crtc.h>
36#include <drm/drm_debugfs_crc.h>
37#include <drm/drm_drv.h>
38#include <drm/drm_print.h>
39
40#include "drm_internal.h"
41
42/**
43 * DOC: CRC ABI
44 *
45 * DRM device drivers can provide to userspace CRC information of each frame as
46 * it reached a given hardware component (a CRC sampling "source").
47 *
48 * Userspace can control generation of CRCs in a given CRTC by writing to the
49 * file dri/0/crtc-N/crc/control in debugfs, with N being the index of the CRTC.
50 * Accepted values are source names (which are driver-specific) and the "auto"
51 * keyword, which will let the driver select a default source of frame CRCs
52 * for this CRTC.
53 *
54 * Once frame CRC generation is enabled, userspace can capture them by reading
55 * the dri/0/crtc-N/crc/data file. Each line in that file contains the frame
56 * number in the first field and then a number of unsigned integer fields
57 * containing the CRC data. Fields are separated by a single space and the number
58 * of CRC fields is source-specific.
59 *
60 * Note that though in some cases the CRC is computed in a specified way and on
61 * the frame contents as supplied by userspace (eDP 1.3), in general the CRC
62 * computation is performed in an unspecified way and on frame contents that have
63 * been already processed in also an unspecified way and thus userspace cannot
64 * rely on being able to generate matching CRC values for the frame contents that
65 * it submits. In this general case, the maximum userspace can do is to compare
66 * the reported CRCs of frames that should have the same contents.
67 *
68 * On the driver side the implementation effort is minimal, drivers only need to
69 * implement &drm_crtc_funcs.set_crc_source and &drm_crtc_funcs.verify_crc_source.
70 * The debugfs files are automatically set up if those vfuncs are set. CRC samples
71 * need to be captured in the driver by calling drm_crtc_add_crc_entry().
72 * Depending on the driver and HW requirements, &drm_crtc_funcs.set_crc_source
73 * may result in a commit (even a full modeset).
74 *
75 * CRC results must be reliable across non-full-modeset atomic commits, so if a
76 * commit via DRM_IOCTL_MODE_ATOMIC would disable or otherwise interfere with
77 * CRC generation, then the driver must mark that commit as a full modeset
78 * (drm_atomic_crtc_needs_modeset() should return true). As a result, to ensure
79 * consistent results, generic userspace must re-setup CRC generation after a
80 * legacy SETCRTC or an atomic commit with DRM_MODE_ATOMIC_ALLOW_MODESET.
81 */
82
83static int crc_control_show(struct seq_file *m, void *data)
84{
85 struct drm_crtc *crtc = m->private;
86
87 if (crtc->funcs->get_crc_sources) {
88 size_t count;
89 const char *const *sources = crtc->funcs->get_crc_sources(crtc,
90 &count);
91 size_t values_cnt;
92 int i;
93
94 if (count == 0 || !sources)
95 goto out;
96
97 for (i = 0; i < count; i++)
98 if (!crtc->funcs->verify_crc_source(crtc, sources[i],
99 &values_cnt)) {
100 if (strcmp(sources[i], crtc->crc.source))
101 seq_printf(m, "%s\n", sources[i]);
102 else
103 seq_printf(m, "%s*\n", sources[i]);
104 }
105 }
106 return 0;
107
108out:
109 seq_printf(m, "%s*\n", crtc->crc.source);
110 return 0;
111}
112
113static int crc_control_open(struct inode *inode, struct file *file)
114{
115 struct drm_crtc *crtc = inode->i_private;
116
117 return single_open(file, crc_control_show, crtc);
118}
119
120static ssize_t crc_control_write(struct file *file, const char __user *ubuf,
121 size_t len, loff_t *offp)
122{
123 struct seq_file *m = file->private_data;
124 struct drm_crtc *crtc = m->private;
125 struct drm_crtc_crc *crc = &crtc->crc;
126 char *source;
127 size_t values_cnt;
128 int ret;
129
130 if (len == 0)
131 return 0;
132
133 if (len > PAGE_SIZE - 1) {
134 DRM_DEBUG_KMS("Expected < %lu bytes into crtc crc control\n",
135 PAGE_SIZE);
136 return -E2BIG;
137 }
138
139 source = memdup_user_nul(ubuf, len);
140 if (IS_ERR(source))
141 return PTR_ERR(source);
142
143 if (source[len - 1] == '\n')
144 source[len - 1] = '\0';
145
146 ret = crtc->funcs->verify_crc_source(crtc, source, &values_cnt);
147 if (ret)
148 return ret;
149
150 spin_lock_irq(&crc->lock);
151
152 if (crc->opened) {
153 spin_unlock_irq(&crc->lock);
154 kfree(source);
155 return -EBUSY;
156 }
157
158 kfree(crc->source);
159 crc->source = source;
160
161 spin_unlock_irq(&crc->lock);
162
163 *offp += len;
164 return len;
165}
166
167static const struct file_operations drm_crtc_crc_control_fops = {
168 .owner = THIS_MODULE,
169 .open = crc_control_open,
170 .read = seq_read,
171 .llseek = seq_lseek,
172 .release = single_release,
173 .write = crc_control_write
174};
175
176static int crtc_crc_data_count(struct drm_crtc_crc *crc)
177{
178 assert_spin_locked(&crc->lock);
179 return CIRC_CNT(crc->head, crc->tail, DRM_CRC_ENTRIES_NR);
180}
181
182static void crtc_crc_cleanup(struct drm_crtc_crc *crc)
183{
184 kfree(crc->entries);
185 crc->overflow = false;
186 crc->entries = NULL;
187 crc->head = 0;
188 crc->tail = 0;
189 crc->values_cnt = 0;
190 crc->opened = false;
191}
192
193static int crtc_crc_open(struct inode *inode, struct file *filep)
194{
195 struct drm_crtc *crtc = inode->i_private;
196 struct drm_crtc_crc *crc = &crtc->crc;
197 struct drm_crtc_crc_entry *entries = NULL;
198 size_t values_cnt;
199 int ret = 0;
200
201 if (drm_drv_uses_atomic_modeset(crtc->dev)) {
202 ret = drm_modeset_lock_single_interruptible(&crtc->mutex);
203 if (ret)
204 return ret;
205
206 if (!crtc->state->active)
207 ret = -EIO;
208 drm_modeset_unlock(&crtc->mutex);
209
210 if (ret)
211 return ret;
212 }
213
214 ret = crtc->funcs->verify_crc_source(crtc, crc->source, &values_cnt);
215 if (ret)
216 return ret;
217
218 if (WARN_ON(values_cnt > DRM_MAX_CRC_NR))
219 return -EINVAL;
220
221 if (WARN_ON(values_cnt == 0))
222 return -EINVAL;
223
224 entries = kcalloc(DRM_CRC_ENTRIES_NR, sizeof(*entries), GFP_KERNEL);
225 if (!entries)
226 return -ENOMEM;
227
228 spin_lock_irq(&crc->lock);
229 if (!crc->opened) {
230 crc->opened = true;
231 crc->entries = entries;
232 crc->values_cnt = values_cnt;
233 } else {
234 ret = -EBUSY;
235 }
236 spin_unlock_irq(&crc->lock);
237
238 if (ret) {
239 kfree(entries);
240 return ret;
241 }
242
243 ret = crtc->funcs->set_crc_source(crtc, crc->source);
244 if (ret)
245 goto err;
246
247 return 0;
248
249err:
250 spin_lock_irq(&crc->lock);
251 crtc_crc_cleanup(crc);
252 spin_unlock_irq(&crc->lock);
253 return ret;
254}
255
256static int crtc_crc_release(struct inode *inode, struct file *filep)
257{
258 struct drm_crtc *crtc = filep->f_inode->i_private;
259 struct drm_crtc_crc *crc = &crtc->crc;
260
261 /* terminate the infinite while loop if 'drm_dp_aux_crc_work' running */
262 spin_lock_irq(&crc->lock);
263 crc->opened = false;
264 spin_unlock_irq(&crc->lock);
265
266 crtc->funcs->set_crc_source(crtc, NULL);
267
268 spin_lock_irq(&crc->lock);
269 crtc_crc_cleanup(crc);
270 spin_unlock_irq(&crc->lock);
271
272 return 0;
273}
274
275/*
276 * 1 frame field of 10 chars plus a number of CRC fields of 10 chars each, space
277 * separated, with a newline at the end and null-terminated.
278 */
279#define LINE_LEN(values_cnt) (10 + 11 * values_cnt + 1 + 1)
280#define MAX_LINE_LEN (LINE_LEN(DRM_MAX_CRC_NR))
281
282static ssize_t crtc_crc_read(struct file *filep, char __user *user_buf,
283 size_t count, loff_t *pos)
284{
285 struct drm_crtc *crtc = filep->f_inode->i_private;
286 struct drm_crtc_crc *crc = &crtc->crc;
287 struct drm_crtc_crc_entry *entry;
288 char buf[MAX_LINE_LEN];
289 int ret, i;
290
291 spin_lock_irq(&crc->lock);
292
293 if (!crc->source) {
294 spin_unlock_irq(&crc->lock);
295 return 0;
296 }
297
298 /* Nothing to read? */
299 while (crtc_crc_data_count(crc) == 0) {
300 if (filep->f_flags & O_NONBLOCK) {
301 spin_unlock_irq(&crc->lock);
302 return -EAGAIN;
303 }
304
305 ret = wait_event_interruptible_lock_irq(crc->wq,
306 crtc_crc_data_count(crc),
307 crc->lock);
308 if (ret) {
309 spin_unlock_irq(&crc->lock);
310 return ret;
311 }
312 }
313
314 /* We know we have an entry to be read */
315 entry = &crc->entries[crc->tail];
316
317 if (count < LINE_LEN(crc->values_cnt)) {
318 spin_unlock_irq(&crc->lock);
319 return -EINVAL;
320 }
321
322 BUILD_BUG_ON_NOT_POWER_OF_2(DRM_CRC_ENTRIES_NR);
323 crc->tail = (crc->tail + 1) & (DRM_CRC_ENTRIES_NR - 1);
324
325 spin_unlock_irq(&crc->lock);
326
327 if (entry->has_frame_counter)
328 sprintf(buf, "0x%08x", entry->frame);
329 else
330 sprintf(buf, "XXXXXXXXXX");
331
332 for (i = 0; i < crc->values_cnt; i++)
333 sprintf(buf + 10 + i * 11, " 0x%08x", entry->crcs[i]);
334 sprintf(buf + 10 + crc->values_cnt * 11, "\n");
335
336 if (copy_to_user(user_buf, buf, LINE_LEN(crc->values_cnt)))
337 return -EFAULT;
338
339 return LINE_LEN(crc->values_cnt);
340}
341
342static __poll_t crtc_crc_poll(struct file *file, poll_table *wait)
343{
344 struct drm_crtc *crtc = file->f_inode->i_private;
345 struct drm_crtc_crc *crc = &crtc->crc;
346 __poll_t ret = 0;
347
348 poll_wait(file, &crc->wq, wait);
349
350 spin_lock_irq(&crc->lock);
351 if (crc->source && crtc_crc_data_count(crc))
352 ret |= EPOLLIN | EPOLLRDNORM;
353 spin_unlock_irq(&crc->lock);
354
355 return ret;
356}
357
358static const struct file_operations drm_crtc_crc_data_fops = {
359 .owner = THIS_MODULE,
360 .open = crtc_crc_open,
361 .read = crtc_crc_read,
362 .poll = crtc_crc_poll,
363 .release = crtc_crc_release,
364};
365
366void drm_debugfs_crtc_crc_add(struct drm_crtc *crtc)
367{
368 struct dentry *crc_ent;
369
370 if (!crtc->funcs->set_crc_source || !crtc->funcs->verify_crc_source)
371 return;
372
373 crc_ent = debugfs_create_dir("crc", crtc->debugfs_entry);
374
375 debugfs_create_file("control", S_IRUGO | S_IWUSR, crc_ent, crtc,
376 &drm_crtc_crc_control_fops);
377 debugfs_create_file("data", S_IRUGO, crc_ent, crtc,
378 &drm_crtc_crc_data_fops);
379}
380
381/**
382 * drm_crtc_add_crc_entry - Add entry with CRC information for a frame
383 * @crtc: CRTC to which the frame belongs
384 * @has_frame: whether this entry has a frame number to go with
385 * @frame: number of the frame these CRCs are about
386 * @crcs: array of CRC values, with length matching #drm_crtc_crc.values_cnt
387 *
388 * For each frame, the driver polls the source of CRCs for new data and calls
389 * this function to add them to the buffer from where userspace reads.
390 */
391int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
392 uint32_t frame, uint32_t *crcs)
393{
394 struct drm_crtc_crc *crc = &crtc->crc;
395 struct drm_crtc_crc_entry *entry;
396 int head, tail;
397 unsigned long flags;
398
399 spin_lock_irqsave(&crc->lock, flags);
400
401 /* Caller may not have noticed yet that userspace has stopped reading */
402 if (!crc->entries) {
403 spin_unlock_irqrestore(&crc->lock, flags);
404 return -EINVAL;
405 }
406
407 head = crc->head;
408 tail = crc->tail;
409
410 if (CIRC_SPACE(head, tail, DRM_CRC_ENTRIES_NR) < 1) {
411 bool was_overflow = crc->overflow;
412
413 crc->overflow = true;
414 spin_unlock_irqrestore(&crc->lock, flags);
415
416 if (!was_overflow)
417 DRM_ERROR("Overflow of CRC buffer, userspace reads too slow.\n");
418
419 return -ENOBUFS;
420 }
421
422 entry = &crc->entries[head];
423 entry->frame = frame;
424 entry->has_frame_counter = has_frame;
425 memcpy(&entry->crcs, crcs, sizeof(*crcs) * crc->values_cnt);
426
427 head = (head + 1) & (DRM_CRC_ENTRIES_NR - 1);
428 crc->head = head;
429
430 spin_unlock_irqrestore(&crc->lock, flags);
431
432 wake_up_interruptible(&crc->wq);
433
434 return 0;
435}
436EXPORT_SYMBOL_GPL(drm_crtc_add_crc_entry);
1/*
2 * Copyright © 2008 Intel Corporation
3 * Copyright © 2016 Collabora Ltd
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22 * IN THE SOFTWARE.
23 *
24 * Based on code from the i915 driver.
25 * Original author: Damien Lespiau <damien.lespiau@intel.com>
26 *
27 */
28
29#include <linux/circ_buf.h>
30#include <linux/ctype.h>
31#include <linux/debugfs.h>
32#include <linux/poll.h>
33#include <linux/uaccess.h>
34
35#include <drm/drm_crtc.h>
36#include <drm/drm_debugfs_crc.h>
37#include <drm/drm_drv.h>
38#include <drm/drm_print.h>
39
40#include "drm_internal.h"
41
42/**
43 * DOC: CRC ABI
44 *
45 * DRM device drivers can provide to userspace CRC information of each frame as
46 * it reached a given hardware component (a CRC sampling "source").
47 *
48 * Userspace can control generation of CRCs in a given CRTC by writing to the
49 * file dri/0/crtc-N/crc/control in debugfs, with N being the :ref:`index of
50 * the CRTC<crtc_index>`. Accepted values are source names (which are
51 * driver-specific) and the "auto" keyword, which will let the driver select a
52 * default source of frame CRCs for this CRTC.
53 *
54 * Once frame CRC generation is enabled, userspace can capture them by reading
55 * the dri/0/crtc-N/crc/data file. Each line in that file contains the frame
56 * number in the first field and then a number of unsigned integer fields
57 * containing the CRC data. Fields are separated by a single space and the number
58 * of CRC fields is source-specific.
59 *
60 * Note that though in some cases the CRC is computed in a specified way and on
61 * the frame contents as supplied by userspace (eDP 1.3), in general the CRC
62 * computation is performed in an unspecified way and on frame contents that have
63 * been already processed in also an unspecified way and thus userspace cannot
64 * rely on being able to generate matching CRC values for the frame contents that
65 * it submits. In this general case, the maximum userspace can do is to compare
66 * the reported CRCs of frames that should have the same contents.
67 *
68 * On the driver side the implementation effort is minimal, drivers only need to
69 * implement &drm_crtc_funcs.set_crc_source and &drm_crtc_funcs.verify_crc_source.
70 * The debugfs files are automatically set up if those vfuncs are set. CRC samples
71 * need to be captured in the driver by calling drm_crtc_add_crc_entry().
72 * Depending on the driver and HW requirements, &drm_crtc_funcs.set_crc_source
73 * may result in a commit (even a full modeset).
74 *
75 * CRC results must be reliable across non-full-modeset atomic commits, so if a
76 * commit via DRM_IOCTL_MODE_ATOMIC would disable or otherwise interfere with
77 * CRC generation, then the driver must mark that commit as a full modeset
78 * (drm_atomic_crtc_needs_modeset() should return true). As a result, to ensure
79 * consistent results, generic userspace must re-setup CRC generation after a
80 * legacy SETCRTC or an atomic commit with DRM_MODE_ATOMIC_ALLOW_MODESET.
81 */
82
83static int crc_control_show(struct seq_file *m, void *data)
84{
85 struct drm_crtc *crtc = m->private;
86
87 if (crtc->funcs->get_crc_sources) {
88 size_t count;
89 const char *const *sources = crtc->funcs->get_crc_sources(crtc,
90 &count);
91 size_t values_cnt;
92 int i;
93
94 if (count == 0 || !sources)
95 goto out;
96
97 for (i = 0; i < count; i++)
98 if (!crtc->funcs->verify_crc_source(crtc, sources[i],
99 &values_cnt)) {
100 if (strcmp(sources[i], crtc->crc.source))
101 seq_printf(m, "%s\n", sources[i]);
102 else
103 seq_printf(m, "%s*\n", sources[i]);
104 }
105 }
106 return 0;
107
108out:
109 seq_printf(m, "%s*\n", crtc->crc.source);
110 return 0;
111}
112
113static int crc_control_open(struct inode *inode, struct file *file)
114{
115 struct drm_crtc *crtc = inode->i_private;
116
117 return single_open(file, crc_control_show, crtc);
118}
119
120static ssize_t crc_control_write(struct file *file, const char __user *ubuf,
121 size_t len, loff_t *offp)
122{
123 struct seq_file *m = file->private_data;
124 struct drm_crtc *crtc = m->private;
125 struct drm_crtc_crc *crc = &crtc->crc;
126 char *source;
127 size_t values_cnt;
128 int ret;
129
130 if (len == 0)
131 return 0;
132
133 if (len > PAGE_SIZE - 1) {
134 DRM_DEBUG_KMS("Expected < %lu bytes into crtc crc control\n",
135 PAGE_SIZE);
136 return -E2BIG;
137 }
138
139 source = memdup_user_nul(ubuf, len);
140 if (IS_ERR(source))
141 return PTR_ERR(source);
142
143 if (source[len - 1] == '\n')
144 source[len - 1] = '\0';
145
146 ret = crtc->funcs->verify_crc_source(crtc, source, &values_cnt);
147 if (ret) {
148 kfree(source);
149 return ret;
150 }
151
152 spin_lock_irq(&crc->lock);
153
154 if (crc->opened) {
155 spin_unlock_irq(&crc->lock);
156 kfree(source);
157 return -EBUSY;
158 }
159
160 kfree(crc->source);
161 crc->source = source;
162
163 spin_unlock_irq(&crc->lock);
164
165 *offp += len;
166 return len;
167}
168
169static const struct file_operations drm_crtc_crc_control_fops = {
170 .owner = THIS_MODULE,
171 .open = crc_control_open,
172 .read = seq_read,
173 .llseek = seq_lseek,
174 .release = single_release,
175 .write = crc_control_write
176};
177
178static int crtc_crc_data_count(struct drm_crtc_crc *crc)
179{
180 assert_spin_locked(&crc->lock);
181 return CIRC_CNT(crc->head, crc->tail, DRM_CRC_ENTRIES_NR);
182}
183
184static void crtc_crc_cleanup(struct drm_crtc_crc *crc)
185{
186 kfree(crc->entries);
187 crc->overflow = false;
188 crc->entries = NULL;
189 crc->head = 0;
190 crc->tail = 0;
191 crc->values_cnt = 0;
192 crc->opened = false;
193}
194
195static int crtc_crc_open(struct inode *inode, struct file *filep)
196{
197 struct drm_crtc *crtc = inode->i_private;
198 struct drm_crtc_crc *crc = &crtc->crc;
199 struct drm_crtc_crc_entry *entries = NULL;
200 size_t values_cnt;
201 int ret = 0;
202
203 if (drm_drv_uses_atomic_modeset(crtc->dev)) {
204 ret = drm_modeset_lock_single_interruptible(&crtc->mutex);
205 if (ret)
206 return ret;
207
208 if (!crtc->state->active)
209 ret = -EIO;
210 drm_modeset_unlock(&crtc->mutex);
211
212 if (ret)
213 return ret;
214 }
215
216 ret = crtc->funcs->verify_crc_source(crtc, crc->source, &values_cnt);
217 if (ret)
218 return ret;
219
220 if (WARN_ON(values_cnt > DRM_MAX_CRC_NR))
221 return -EINVAL;
222
223 if (WARN_ON(values_cnt == 0))
224 return -EINVAL;
225
226 entries = kcalloc(DRM_CRC_ENTRIES_NR, sizeof(*entries), GFP_KERNEL);
227 if (!entries)
228 return -ENOMEM;
229
230 spin_lock_irq(&crc->lock);
231 if (!crc->opened) {
232 crc->opened = true;
233 crc->entries = entries;
234 crc->values_cnt = values_cnt;
235 } else {
236 ret = -EBUSY;
237 }
238 spin_unlock_irq(&crc->lock);
239
240 if (ret) {
241 kfree(entries);
242 return ret;
243 }
244
245 ret = crtc->funcs->set_crc_source(crtc, crc->source);
246 if (ret)
247 goto err;
248
249 return 0;
250
251err:
252 spin_lock_irq(&crc->lock);
253 crtc_crc_cleanup(crc);
254 spin_unlock_irq(&crc->lock);
255 return ret;
256}
257
258static int crtc_crc_release(struct inode *inode, struct file *filep)
259{
260 struct drm_crtc *crtc = filep->f_inode->i_private;
261 struct drm_crtc_crc *crc = &crtc->crc;
262
263 /* terminate the infinite while loop if 'drm_dp_aux_crc_work' running */
264 spin_lock_irq(&crc->lock);
265 crc->opened = false;
266 spin_unlock_irq(&crc->lock);
267
268 crtc->funcs->set_crc_source(crtc, NULL);
269
270 spin_lock_irq(&crc->lock);
271 crtc_crc_cleanup(crc);
272 spin_unlock_irq(&crc->lock);
273
274 return 0;
275}
276
277/*
278 * 1 frame field of 10 chars plus a number of CRC fields of 10 chars each, space
279 * separated, with a newline at the end and null-terminated.
280 */
281#define LINE_LEN(values_cnt) (10 + 11 * values_cnt + 1 + 1)
282#define MAX_LINE_LEN (LINE_LEN(DRM_MAX_CRC_NR))
283
284static ssize_t crtc_crc_read(struct file *filep, char __user *user_buf,
285 size_t count, loff_t *pos)
286{
287 struct drm_crtc *crtc = filep->f_inode->i_private;
288 struct drm_crtc_crc *crc = &crtc->crc;
289 struct drm_crtc_crc_entry *entry;
290 char buf[MAX_LINE_LEN];
291 int ret, i;
292
293 spin_lock_irq(&crc->lock);
294
295 if (!crc->source) {
296 spin_unlock_irq(&crc->lock);
297 return 0;
298 }
299
300 /* Nothing to read? */
301 while (crtc_crc_data_count(crc) == 0) {
302 if (filep->f_flags & O_NONBLOCK) {
303 spin_unlock_irq(&crc->lock);
304 return -EAGAIN;
305 }
306
307 ret = wait_event_interruptible_lock_irq(crc->wq,
308 crtc_crc_data_count(crc),
309 crc->lock);
310 if (ret) {
311 spin_unlock_irq(&crc->lock);
312 return ret;
313 }
314 }
315
316 /* We know we have an entry to be read */
317 entry = &crc->entries[crc->tail];
318
319 if (count < LINE_LEN(crc->values_cnt)) {
320 spin_unlock_irq(&crc->lock);
321 return -EINVAL;
322 }
323
324 BUILD_BUG_ON_NOT_POWER_OF_2(DRM_CRC_ENTRIES_NR);
325 crc->tail = (crc->tail + 1) & (DRM_CRC_ENTRIES_NR - 1);
326
327 spin_unlock_irq(&crc->lock);
328
329 if (entry->has_frame_counter)
330 sprintf(buf, "0x%08x", entry->frame);
331 else
332 sprintf(buf, "XXXXXXXXXX");
333
334 for (i = 0; i < crc->values_cnt; i++)
335 sprintf(buf + 10 + i * 11, " 0x%08x", entry->crcs[i]);
336 sprintf(buf + 10 + crc->values_cnt * 11, "\n");
337
338 if (copy_to_user(user_buf, buf, LINE_LEN(crc->values_cnt)))
339 return -EFAULT;
340
341 return LINE_LEN(crc->values_cnt);
342}
343
344static __poll_t crtc_crc_poll(struct file *file, poll_table *wait)
345{
346 struct drm_crtc *crtc = file->f_inode->i_private;
347 struct drm_crtc_crc *crc = &crtc->crc;
348 __poll_t ret = 0;
349
350 poll_wait(file, &crc->wq, wait);
351
352 spin_lock_irq(&crc->lock);
353 if (crc->source && crtc_crc_data_count(crc))
354 ret |= EPOLLIN | EPOLLRDNORM;
355 spin_unlock_irq(&crc->lock);
356
357 return ret;
358}
359
360static const struct file_operations drm_crtc_crc_data_fops = {
361 .owner = THIS_MODULE,
362 .open = crtc_crc_open,
363 .read = crtc_crc_read,
364 .poll = crtc_crc_poll,
365 .release = crtc_crc_release,
366};
367
368void drm_debugfs_crtc_crc_add(struct drm_crtc *crtc)
369{
370 struct dentry *crc_ent;
371
372 if (!crtc->funcs->set_crc_source || !crtc->funcs->verify_crc_source)
373 return;
374
375 crc_ent = debugfs_create_dir("crc", crtc->debugfs_entry);
376
377 debugfs_create_file("control", S_IRUGO | S_IWUSR, crc_ent, crtc,
378 &drm_crtc_crc_control_fops);
379 debugfs_create_file("data", S_IRUGO, crc_ent, crtc,
380 &drm_crtc_crc_data_fops);
381}
382
383/**
384 * drm_crtc_add_crc_entry - Add entry with CRC information for a frame
385 * @crtc: CRTC to which the frame belongs
386 * @has_frame: whether this entry has a frame number to go with
387 * @frame: number of the frame these CRCs are about
388 * @crcs: array of CRC values, with length matching #drm_crtc_crc.values_cnt
389 *
390 * For each frame, the driver polls the source of CRCs for new data and calls
391 * this function to add them to the buffer from where userspace reads.
392 */
393int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
394 uint32_t frame, uint32_t *crcs)
395{
396 struct drm_crtc_crc *crc = &crtc->crc;
397 struct drm_crtc_crc_entry *entry;
398 int head, tail;
399 unsigned long flags;
400
401 spin_lock_irqsave(&crc->lock, flags);
402
403 /* Caller may not have noticed yet that userspace has stopped reading */
404 if (!crc->entries) {
405 spin_unlock_irqrestore(&crc->lock, flags);
406 return -EINVAL;
407 }
408
409 head = crc->head;
410 tail = crc->tail;
411
412 if (CIRC_SPACE(head, tail, DRM_CRC_ENTRIES_NR) < 1) {
413 bool was_overflow = crc->overflow;
414
415 crc->overflow = true;
416 spin_unlock_irqrestore(&crc->lock, flags);
417
418 if (!was_overflow)
419 DRM_ERROR("Overflow of CRC buffer, userspace reads too slow.\n");
420
421 return -ENOBUFS;
422 }
423
424 entry = &crc->entries[head];
425 entry->frame = frame;
426 entry->has_frame_counter = has_frame;
427 memcpy(&entry->crcs, crcs, sizeof(*crcs) * crc->values_cnt);
428
429 head = (head + 1) & (DRM_CRC_ENTRIES_NR - 1);
430 crc->head = head;
431
432 spin_unlock_irqrestore(&crc->lock, flags);
433
434 wake_up_interruptible(&crc->wq);
435
436 return 0;
437}
438EXPORT_SYMBOL_GPL(drm_crtc_add_crc_entry);