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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 :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);
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 <drm/drmP.h>
33#include "drm_internal.h"
34
35/**
36 * DOC: CRC ABI
37 *
38 * DRM device drivers can provide to userspace CRC information of each frame as
39 * it reached a given hardware component (a CRC sampling "source").
40 *
41 * Userspace can control generation of CRCs in a given CRTC by writing to the
42 * file dri/0/crtc-N/crc/control in debugfs, with N being the index of the CRTC.
43 * Accepted values are source names (which are driver-specific) and the "auto"
44 * keyword, which will let the driver select a default source of frame CRCs
45 * for this CRTC.
46 *
47 * Once frame CRC generation is enabled, userspace can capture them by reading
48 * the dri/0/crtc-N/crc/data file. Each line in that file contains the frame
49 * number in the first field and then a number of unsigned integer fields
50 * containing the CRC data. Fields are separated by a single space and the number
51 * of CRC fields is source-specific.
52 *
53 * Note that though in some cases the CRC is computed in a specified way and on
54 * the frame contents as supplied by userspace (eDP 1.3), in general the CRC
55 * computation is performed in an unspecified way and on frame contents that have
56 * been already processed in also an unspecified way and thus userspace cannot
57 * rely on being able to generate matching CRC values for the frame contents that
58 * it submits. In this general case, the maximum userspace can do is to compare
59 * the reported CRCs of frames that should have the same contents.
60 *
61 * On the driver side the implementation effort is minimal, drivers only need to
62 * implement &drm_crtc_funcs.set_crc_source. The debugfs files are automatically
63 * set up if that vfunc is set. CRC samples need to be captured in the driver by
64 * calling drm_crtc_add_crc_entry().
65 */
66
67static int crc_control_show(struct seq_file *m, void *data)
68{
69 struct drm_crtc *crtc = m->private;
70
71 seq_printf(m, "%s\n", crtc->crc.source);
72
73 return 0;
74}
75
76static int crc_control_open(struct inode *inode, struct file *file)
77{
78 struct drm_crtc *crtc = inode->i_private;
79
80 return single_open(file, crc_control_show, crtc);
81}
82
83static ssize_t crc_control_write(struct file *file, const char __user *ubuf,
84 size_t len, loff_t *offp)
85{
86 struct seq_file *m = file->private_data;
87 struct drm_crtc *crtc = m->private;
88 struct drm_crtc_crc *crc = &crtc->crc;
89 char *source;
90
91 if (len == 0)
92 return 0;
93
94 if (len > PAGE_SIZE - 1) {
95 DRM_DEBUG_KMS("Expected < %lu bytes into crtc crc control\n",
96 PAGE_SIZE);
97 return -E2BIG;
98 }
99
100 source = memdup_user_nul(ubuf, len);
101 if (IS_ERR(source))
102 return PTR_ERR(source);
103
104 if (source[len] == '\n')
105 source[len] = '\0';
106
107 spin_lock_irq(&crc->lock);
108
109 if (crc->opened) {
110 spin_unlock_irq(&crc->lock);
111 kfree(source);
112 return -EBUSY;
113 }
114
115 kfree(crc->source);
116 crc->source = source;
117
118 spin_unlock_irq(&crc->lock);
119
120 *offp += len;
121 return len;
122}
123
124static const struct file_operations drm_crtc_crc_control_fops = {
125 .owner = THIS_MODULE,
126 .open = crc_control_open,
127 .read = seq_read,
128 .llseek = seq_lseek,
129 .release = single_release,
130 .write = crc_control_write
131};
132
133static int crtc_crc_data_count(struct drm_crtc_crc *crc)
134{
135 assert_spin_locked(&crc->lock);
136 return CIRC_CNT(crc->head, crc->tail, DRM_CRC_ENTRIES_NR);
137}
138
139static void crtc_crc_cleanup(struct drm_crtc_crc *crc)
140{
141 kfree(crc->entries);
142 crc->entries = NULL;
143 crc->head = 0;
144 crc->tail = 0;
145 crc->values_cnt = 0;
146 crc->opened = false;
147}
148
149static int crtc_crc_open(struct inode *inode, struct file *filep)
150{
151 struct drm_crtc *crtc = inode->i_private;
152 struct drm_crtc_crc *crc = &crtc->crc;
153 struct drm_crtc_crc_entry *entries = NULL;
154 size_t values_cnt;
155 int ret = 0;
156
157 if (drm_drv_uses_atomic_modeset(crtc->dev)) {
158 ret = drm_modeset_lock_single_interruptible(&crtc->mutex);
159 if (ret)
160 return ret;
161
162 if (!crtc->state->active)
163 ret = -EIO;
164 drm_modeset_unlock(&crtc->mutex);
165
166 if (ret)
167 return ret;
168 }
169
170 spin_lock_irq(&crc->lock);
171 if (!crc->opened)
172 crc->opened = true;
173 else
174 ret = -EBUSY;
175 spin_unlock_irq(&crc->lock);
176
177 if (ret)
178 return ret;
179
180 ret = crtc->funcs->set_crc_source(crtc, crc->source, &values_cnt);
181 if (ret)
182 goto err;
183
184 if (WARN_ON(values_cnt > DRM_MAX_CRC_NR)) {
185 ret = -EINVAL;
186 goto err_disable;
187 }
188
189 if (WARN_ON(values_cnt == 0)) {
190 ret = -EINVAL;
191 goto err_disable;
192 }
193
194 entries = kcalloc(DRM_CRC_ENTRIES_NR, sizeof(*entries), GFP_KERNEL);
195 if (!entries) {
196 ret = -ENOMEM;
197 goto err_disable;
198 }
199
200 spin_lock_irq(&crc->lock);
201 crc->entries = entries;
202 crc->values_cnt = values_cnt;
203
204 /*
205 * Only return once we got a first frame, so userspace doesn't have to
206 * guess when this particular piece of HW will be ready to start
207 * generating CRCs.
208 */
209 ret = wait_event_interruptible_lock_irq(crc->wq,
210 crtc_crc_data_count(crc),
211 crc->lock);
212 spin_unlock_irq(&crc->lock);
213
214 if (ret)
215 goto err_disable;
216
217 return 0;
218
219err_disable:
220 crtc->funcs->set_crc_source(crtc, NULL, &values_cnt);
221err:
222 spin_lock_irq(&crc->lock);
223 crtc_crc_cleanup(crc);
224 spin_unlock_irq(&crc->lock);
225 return ret;
226}
227
228static int crtc_crc_release(struct inode *inode, struct file *filep)
229{
230 struct drm_crtc *crtc = filep->f_inode->i_private;
231 struct drm_crtc_crc *crc = &crtc->crc;
232 size_t values_cnt;
233
234 crtc->funcs->set_crc_source(crtc, NULL, &values_cnt);
235
236 spin_lock_irq(&crc->lock);
237 crtc_crc_cleanup(crc);
238 spin_unlock_irq(&crc->lock);
239
240 return 0;
241}
242
243/*
244 * 1 frame field of 10 chars plus a number of CRC fields of 10 chars each, space
245 * separated, with a newline at the end and null-terminated.
246 */
247#define LINE_LEN(values_cnt) (10 + 11 * values_cnt + 1 + 1)
248#define MAX_LINE_LEN (LINE_LEN(DRM_MAX_CRC_NR))
249
250static ssize_t crtc_crc_read(struct file *filep, char __user *user_buf,
251 size_t count, loff_t *pos)
252{
253 struct drm_crtc *crtc = filep->f_inode->i_private;
254 struct drm_crtc_crc *crc = &crtc->crc;
255 struct drm_crtc_crc_entry *entry;
256 char buf[MAX_LINE_LEN];
257 int ret, i;
258
259 spin_lock_irq(&crc->lock);
260
261 if (!crc->source) {
262 spin_unlock_irq(&crc->lock);
263 return 0;
264 }
265
266 /* Nothing to read? */
267 while (crtc_crc_data_count(crc) == 0) {
268 if (filep->f_flags & O_NONBLOCK) {
269 spin_unlock_irq(&crc->lock);
270 return -EAGAIN;
271 }
272
273 ret = wait_event_interruptible_lock_irq(crc->wq,
274 crtc_crc_data_count(crc),
275 crc->lock);
276 if (ret) {
277 spin_unlock_irq(&crc->lock);
278 return ret;
279 }
280 }
281
282 /* We know we have an entry to be read */
283 entry = &crc->entries[crc->tail];
284
285 if (count < LINE_LEN(crc->values_cnt)) {
286 spin_unlock_irq(&crc->lock);
287 return -EINVAL;
288 }
289
290 BUILD_BUG_ON_NOT_POWER_OF_2(DRM_CRC_ENTRIES_NR);
291 crc->tail = (crc->tail + 1) & (DRM_CRC_ENTRIES_NR - 1);
292
293 spin_unlock_irq(&crc->lock);
294
295 if (entry->has_frame_counter)
296 sprintf(buf, "0x%08x", entry->frame);
297 else
298 sprintf(buf, "XXXXXXXXXX");
299
300 for (i = 0; i < crc->values_cnt; i++)
301 sprintf(buf + 10 + i * 11, " 0x%08x", entry->crcs[i]);
302 sprintf(buf + 10 + crc->values_cnt * 11, "\n");
303
304 if (copy_to_user(user_buf, buf, LINE_LEN(crc->values_cnt)))
305 return -EFAULT;
306
307 return LINE_LEN(crc->values_cnt);
308}
309
310static unsigned int crtc_crc_poll(struct file *file, poll_table *wait)
311{
312 struct drm_crtc *crtc = file->f_inode->i_private;
313 struct drm_crtc_crc *crc = &crtc->crc;
314 unsigned ret;
315
316 poll_wait(file, &crc->wq, wait);
317
318 spin_lock_irq(&crc->lock);
319 if (crc->source && crtc_crc_data_count(crc))
320 ret = POLLIN | POLLRDNORM;
321 else
322 ret = 0;
323 spin_unlock_irq(&crc->lock);
324
325 return ret;
326}
327
328static const struct file_operations drm_crtc_crc_data_fops = {
329 .owner = THIS_MODULE,
330 .open = crtc_crc_open,
331 .read = crtc_crc_read,
332 .poll = crtc_crc_poll,
333 .release = crtc_crc_release,
334};
335
336int drm_debugfs_crtc_crc_add(struct drm_crtc *crtc)
337{
338 struct dentry *crc_ent, *ent;
339
340 if (!crtc->funcs->set_crc_source)
341 return 0;
342
343 crc_ent = debugfs_create_dir("crc", crtc->debugfs_entry);
344 if (!crc_ent)
345 return -ENOMEM;
346
347 ent = debugfs_create_file("control", S_IRUGO, crc_ent, crtc,
348 &drm_crtc_crc_control_fops);
349 if (!ent)
350 goto error;
351
352 ent = debugfs_create_file("data", S_IRUGO, crc_ent, crtc,
353 &drm_crtc_crc_data_fops);
354 if (!ent)
355 goto error;
356
357 return 0;
358
359error:
360 debugfs_remove_recursive(crc_ent);
361
362 return -ENOMEM;
363}
364
365/**
366 * drm_crtc_add_crc_entry - Add entry with CRC information for a frame
367 * @crtc: CRTC to which the frame belongs
368 * @has_frame: whether this entry has a frame number to go with
369 * @frame: number of the frame these CRCs are about
370 * @crcs: array of CRC values, with length matching #drm_crtc_crc.values_cnt
371 *
372 * For each frame, the driver polls the source of CRCs for new data and calls
373 * this function to add them to the buffer from where userspace reads.
374 */
375int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
376 uint32_t frame, uint32_t *crcs)
377{
378 struct drm_crtc_crc *crc = &crtc->crc;
379 struct drm_crtc_crc_entry *entry;
380 int head, tail;
381
382 spin_lock(&crc->lock);
383
384 /* Caller may not have noticed yet that userspace has stopped reading */
385 if (!crc->entries) {
386 spin_unlock(&crc->lock);
387 return -EINVAL;
388 }
389
390 head = crc->head;
391 tail = crc->tail;
392
393 if (CIRC_SPACE(head, tail, DRM_CRC_ENTRIES_NR) < 1) {
394 spin_unlock(&crc->lock);
395 DRM_ERROR("Overflow of CRC buffer, userspace reads too slow.\n");
396 return -ENOBUFS;
397 }
398
399 entry = &crc->entries[head];
400 entry->frame = frame;
401 entry->has_frame_counter = has_frame;
402 memcpy(&entry->crcs, crcs, sizeof(*crcs) * crc->values_cnt);
403
404 head = (head + 1) & (DRM_CRC_ENTRIES_NR - 1);
405 crc->head = head;
406
407 spin_unlock(&crc->lock);
408
409 wake_up_interruptible(&crc->wq);
410
411 return 0;
412}
413EXPORT_SYMBOL_GPL(drm_crtc_add_crc_entry);