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9ea393d8 | 1 | // SPDX-License-Identifier: GPL-2.0 |
7bd1d409 AS |
2 | /* |
3 | * System Trace Module (STM) infrastructure | |
4 | * Copyright (c) 2014, Intel Corporation. | |
5 | * | |
7bd1d409 AS |
6 | * STM class implements generic infrastructure for System Trace Module devices |
7 | * as defined in MIPI STPv2 specification. | |
8 | */ | |
9 | ||
8e0469a4 | 10 | #include <linux/pm_runtime.h> |
7bd1d409 AS |
11 | #include <linux/uaccess.h> |
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/device.h> | |
15 | #include <linux/compat.h> | |
16 | #include <linux/kdev_t.h> | |
17 | #include <linux/srcu.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/stm.h> | |
20 | #include <linux/fs.h> | |
21 | #include <linux/mm.h> | |
806e3087 | 22 | #include <linux/vmalloc.h> |
7bd1d409 AS |
23 | #include "stm.h" |
24 | ||
25 | #include <uapi/linux/stm.h> | |
26 | ||
27 | static unsigned int stm_core_up; | |
28 | ||
29 | /* | |
30 | * The SRCU here makes sure that STM device doesn't disappear from under a | |
31 | * stm_source_write() caller, which may want to have as little overhead as | |
32 | * possible. | |
33 | */ | |
34 | static struct srcu_struct stm_source_srcu; | |
35 | ||
36 | static ssize_t masters_show(struct device *dev, | |
37 | struct device_attribute *attr, | |
38 | char *buf) | |
39 | { | |
40 | struct stm_device *stm = to_stm_device(dev); | |
41 | int ret; | |
42 | ||
43 | ret = sprintf(buf, "%u %u\n", stm->data->sw_start, stm->data->sw_end); | |
44 | ||
45 | return ret; | |
46 | } | |
47 | ||
48 | static DEVICE_ATTR_RO(masters); | |
49 | ||
50 | static ssize_t channels_show(struct device *dev, | |
51 | struct device_attribute *attr, | |
52 | char *buf) | |
53 | { | |
54 | struct stm_device *stm = to_stm_device(dev); | |
55 | int ret; | |
56 | ||
57 | ret = sprintf(buf, "%u\n", stm->data->sw_nchannels); | |
58 | ||
59 | return ret; | |
60 | } | |
61 | ||
62 | static DEVICE_ATTR_RO(channels); | |
63 | ||
8e996a28 AS |
64 | static ssize_t hw_override_show(struct device *dev, |
65 | struct device_attribute *attr, | |
66 | char *buf) | |
67 | { | |
68 | struct stm_device *stm = to_stm_device(dev); | |
69 | int ret; | |
70 | ||
71 | ret = sprintf(buf, "%u\n", stm->data->hw_override); | |
72 | ||
73 | return ret; | |
74 | } | |
75 | ||
76 | static DEVICE_ATTR_RO(hw_override); | |
77 | ||
7bd1d409 AS |
78 | static struct attribute *stm_attrs[] = { |
79 | &dev_attr_masters.attr, | |
80 | &dev_attr_channels.attr, | |
8e996a28 | 81 | &dev_attr_hw_override.attr, |
7bd1d409 AS |
82 | NULL, |
83 | }; | |
84 | ||
85 | ATTRIBUTE_GROUPS(stm); | |
86 | ||
87 | static struct class stm_class = { | |
88 | .name = "stm", | |
89 | .dev_groups = stm_groups, | |
90 | }; | |
91 | ||
92 | static int stm_dev_match(struct device *dev, const void *data) | |
93 | { | |
94 | const char *name = data; | |
95 | ||
96 | return sysfs_streq(name, dev_name(dev)); | |
97 | } | |
98 | ||
99 | /** | |
100 | * stm_find_device() - find stm device by name | |
101 | * @buf: character buffer containing the name | |
102 | * | |
103 | * This is called when either policy gets assigned to an stm device or an | |
104 | * stm_source device gets linked to an stm device. | |
105 | * | |
106 | * This grabs device's reference (get_device()) and module reference, both | |
107 | * of which the calling path needs to make sure to drop with stm_put_device(). | |
108 | * | |
109 | * Return: stm device pointer or null if lookup failed. | |
110 | */ | |
111 | struct stm_device *stm_find_device(const char *buf) | |
112 | { | |
113 | struct stm_device *stm; | |
114 | struct device *dev; | |
115 | ||
116 | if (!stm_core_up) | |
117 | return NULL; | |
118 | ||
119 | dev = class_find_device(&stm_class, NULL, buf, stm_dev_match); | |
120 | if (!dev) | |
121 | return NULL; | |
122 | ||
123 | stm = to_stm_device(dev); | |
124 | if (!try_module_get(stm->owner)) { | |
f7c81c71 | 125 | /* matches class_find_device() above */ |
7bd1d409 AS |
126 | put_device(dev); |
127 | return NULL; | |
128 | } | |
129 | ||
130 | return stm; | |
131 | } | |
132 | ||
133 | /** | |
134 | * stm_put_device() - drop references on the stm device | |
135 | * @stm: stm device, previously acquired by stm_find_device() | |
136 | * | |
137 | * This drops the module reference and device reference taken by | |
f7c81c71 | 138 | * stm_find_device() or stm_char_open(). |
7bd1d409 AS |
139 | */ |
140 | void stm_put_device(struct stm_device *stm) | |
141 | { | |
142 | module_put(stm->owner); | |
143 | put_device(&stm->dev); | |
144 | } | |
145 | ||
146 | /* | |
147 | * Internally we only care about software-writable masters here, that is the | |
148 | * ones in the range [stm_data->sw_start..stm_data..sw_end], however we need | |
149 | * original master numbers to be visible externally, since they are the ones | |
150 | * that will appear in the STP stream. Thus, the internal bookkeeping uses | |
151 | * $master - stm_data->sw_start to reference master descriptors and such. | |
152 | */ | |
153 | ||
154 | #define __stm_master(_s, _m) \ | |
155 | ((_s)->masters[(_m) - (_s)->data->sw_start]) | |
156 | ||
157 | static inline struct stp_master * | |
158 | stm_master(struct stm_device *stm, unsigned int idx) | |
159 | { | |
160 | if (idx < stm->data->sw_start || idx > stm->data->sw_end) | |
161 | return NULL; | |
162 | ||
163 | return __stm_master(stm, idx); | |
164 | } | |
165 | ||
166 | static int stp_master_alloc(struct stm_device *stm, unsigned int idx) | |
167 | { | |
168 | struct stp_master *master; | |
169 | size_t size; | |
170 | ||
171 | size = ALIGN(stm->data->sw_nchannels, 8) / 8; | |
172 | size += sizeof(struct stp_master); | |
173 | master = kzalloc(size, GFP_ATOMIC); | |
174 | if (!master) | |
175 | return -ENOMEM; | |
176 | ||
177 | master->nr_free = stm->data->sw_nchannels; | |
178 | __stm_master(stm, idx) = master; | |
179 | ||
180 | return 0; | |
181 | } | |
182 | ||
183 | static void stp_master_free(struct stm_device *stm, unsigned int idx) | |
184 | { | |
185 | struct stp_master *master = stm_master(stm, idx); | |
186 | ||
187 | if (!master) | |
188 | return; | |
189 | ||
190 | __stm_master(stm, idx) = NULL; | |
191 | kfree(master); | |
192 | } | |
193 | ||
194 | static void stm_output_claim(struct stm_device *stm, struct stm_output *output) | |
195 | { | |
196 | struct stp_master *master = stm_master(stm, output->master); | |
197 | ||
cde4ad83 AS |
198 | lockdep_assert_held(&stm->mc_lock); |
199 | lockdep_assert_held(&output->lock); | |
200 | ||
7bd1d409 AS |
201 | if (WARN_ON_ONCE(master->nr_free < output->nr_chans)) |
202 | return; | |
203 | ||
204 | bitmap_allocate_region(&master->chan_map[0], output->channel, | |
205 | ilog2(output->nr_chans)); | |
206 | ||
207 | master->nr_free -= output->nr_chans; | |
208 | } | |
209 | ||
210 | static void | |
211 | stm_output_disclaim(struct stm_device *stm, struct stm_output *output) | |
212 | { | |
213 | struct stp_master *master = stm_master(stm, output->master); | |
214 | ||
cde4ad83 AS |
215 | lockdep_assert_held(&stm->mc_lock); |
216 | lockdep_assert_held(&output->lock); | |
217 | ||
7bd1d409 AS |
218 | bitmap_release_region(&master->chan_map[0], output->channel, |
219 | ilog2(output->nr_chans)); | |
220 | ||
221 | output->nr_chans = 0; | |
222 | master->nr_free += output->nr_chans; | |
223 | } | |
224 | ||
225 | /* | |
226 | * This is like bitmap_find_free_region(), except it can ignore @start bits | |
227 | * at the beginning. | |
228 | */ | |
229 | static int find_free_channels(unsigned long *bitmap, unsigned int start, | |
230 | unsigned int end, unsigned int width) | |
231 | { | |
232 | unsigned int pos; | |
233 | int i; | |
234 | ||
235 | for (pos = start; pos < end + 1; pos = ALIGN(pos, width)) { | |
236 | pos = find_next_zero_bit(bitmap, end + 1, pos); | |
237 | if (pos + width > end + 1) | |
238 | break; | |
239 | ||
240 | if (pos & (width - 1)) | |
241 | continue; | |
242 | ||
243 | for (i = 1; i < width && !test_bit(pos + i, bitmap); i++) | |
244 | ; | |
245 | if (i == width) | |
246 | return pos; | |
247 | } | |
248 | ||
249 | return -1; | |
250 | } | |
251 | ||
f45f40ad | 252 | static int |
7bd1d409 AS |
253 | stm_find_master_chan(struct stm_device *stm, unsigned int width, |
254 | unsigned int *mstart, unsigned int mend, | |
255 | unsigned int *cstart, unsigned int cend) | |
256 | { | |
257 | struct stp_master *master; | |
258 | unsigned int midx; | |
259 | int pos, err; | |
260 | ||
261 | for (midx = *mstart; midx <= mend; midx++) { | |
262 | if (!stm_master(stm, midx)) { | |
263 | err = stp_master_alloc(stm, midx); | |
264 | if (err) | |
265 | return err; | |
266 | } | |
267 | ||
268 | master = stm_master(stm, midx); | |
269 | ||
270 | if (!master->nr_free) | |
271 | continue; | |
272 | ||
273 | pos = find_free_channels(master->chan_map, *cstart, cend, | |
274 | width); | |
275 | if (pos < 0) | |
276 | continue; | |
277 | ||
278 | *mstart = midx; | |
279 | *cstart = pos; | |
280 | return 0; | |
281 | } | |
282 | ||
283 | return -ENOSPC; | |
284 | } | |
285 | ||
286 | static int stm_output_assign(struct stm_device *stm, unsigned int width, | |
287 | struct stp_policy_node *policy_node, | |
288 | struct stm_output *output) | |
289 | { | |
290 | unsigned int midx, cidx, mend, cend; | |
291 | int ret = -EINVAL; | |
292 | ||
293 | if (width > stm->data->sw_nchannels) | |
294 | return -EINVAL; | |
295 | ||
cb6102bd AS |
296 | /* We no longer accept policy_node==NULL here */ |
297 | if (WARN_ON_ONCE(!policy_node)) | |
298 | return -EINVAL; | |
299 | ||
300 | /* | |
301 | * Also, the caller holds reference to policy_node, so it won't | |
302 | * disappear on us. | |
303 | */ | |
304 | stp_policy_node_get_ranges(policy_node, &midx, &mend, &cidx, &cend); | |
7bd1d409 AS |
305 | |
306 | spin_lock(&stm->mc_lock); | |
cde4ad83 | 307 | spin_lock(&output->lock); |
7bd1d409 AS |
308 | /* output is already assigned -- shouldn't happen */ |
309 | if (WARN_ON_ONCE(output->nr_chans)) | |
310 | goto unlock; | |
311 | ||
312 | ret = stm_find_master_chan(stm, width, &midx, mend, &cidx, cend); | |
f45f40ad | 313 | if (ret < 0) |
7bd1d409 AS |
314 | goto unlock; |
315 | ||
316 | output->master = midx; | |
317 | output->channel = cidx; | |
318 | output->nr_chans = width; | |
c7fd62bc AS |
319 | if (stm->pdrv->output_open) { |
320 | void *priv = stp_policy_node_priv(policy_node); | |
321 | ||
322 | if (WARN_ON_ONCE(!priv)) | |
323 | goto unlock; | |
324 | ||
325 | /* configfs subsys mutex is held by the caller */ | |
326 | ret = stm->pdrv->output_open(priv, output); | |
327 | if (ret) | |
328 | goto unlock; | |
329 | } | |
330 | ||
7bd1d409 AS |
331 | stm_output_claim(stm, output); |
332 | dev_dbg(&stm->dev, "assigned %u:%u (+%u)\n", midx, cidx, width); | |
333 | ||
334 | ret = 0; | |
335 | unlock: | |
c7fd62bc AS |
336 | if (ret) |
337 | output->nr_chans = 0; | |
338 | ||
cde4ad83 | 339 | spin_unlock(&output->lock); |
7bd1d409 AS |
340 | spin_unlock(&stm->mc_lock); |
341 | ||
342 | return ret; | |
343 | } | |
344 | ||
345 | static void stm_output_free(struct stm_device *stm, struct stm_output *output) | |
346 | { | |
347 | spin_lock(&stm->mc_lock); | |
cde4ad83 | 348 | spin_lock(&output->lock); |
7bd1d409 AS |
349 | if (output->nr_chans) |
350 | stm_output_disclaim(stm, output); | |
c7fd62bc AS |
351 | if (stm->pdrv && stm->pdrv->output_close) |
352 | stm->pdrv->output_close(output); | |
cde4ad83 | 353 | spin_unlock(&output->lock); |
7bd1d409 AS |
354 | spin_unlock(&stm->mc_lock); |
355 | } | |
356 | ||
cde4ad83 AS |
357 | static void stm_output_init(struct stm_output *output) |
358 | { | |
359 | spin_lock_init(&output->lock); | |
360 | } | |
361 | ||
7bd1d409 AS |
362 | static int major_match(struct device *dev, const void *data) |
363 | { | |
364 | unsigned int major = *(unsigned int *)data; | |
365 | ||
366 | return MAJOR(dev->devt) == major; | |
367 | } | |
368 | ||
c7fd62bc AS |
369 | /* |
370 | * Framing protocol management | |
371 | * Modules can implement STM protocol drivers and (un-)register them | |
372 | * with the STM class framework. | |
373 | */ | |
374 | static struct list_head stm_pdrv_head; | |
375 | static struct mutex stm_pdrv_mutex; | |
376 | ||
377 | struct stm_pdrv_entry { | |
378 | struct list_head entry; | |
379 | const struct stm_protocol_driver *pdrv; | |
380 | const struct config_item_type *node_type; | |
381 | }; | |
382 | ||
383 | static const struct stm_pdrv_entry * | |
384 | __stm_lookup_protocol(const char *name) | |
385 | { | |
386 | struct stm_pdrv_entry *pe; | |
387 | ||
388 | /* | |
389 | * If no name is given (NULL or ""), fall back to "p_basic". | |
390 | */ | |
391 | if (!name || !*name) | |
392 | name = "p_basic"; | |
393 | ||
394 | list_for_each_entry(pe, &stm_pdrv_head, entry) { | |
395 | if (!strcmp(name, pe->pdrv->name)) | |
396 | return pe; | |
397 | } | |
398 | ||
399 | return NULL; | |
400 | } | |
401 | ||
402 | int stm_register_protocol(const struct stm_protocol_driver *pdrv) | |
403 | { | |
404 | struct stm_pdrv_entry *pe = NULL; | |
405 | int ret = -ENOMEM; | |
406 | ||
407 | mutex_lock(&stm_pdrv_mutex); | |
408 | ||
409 | if (__stm_lookup_protocol(pdrv->name)) { | |
410 | ret = -EEXIST; | |
411 | goto unlock; | |
412 | } | |
413 | ||
414 | pe = kzalloc(sizeof(*pe), GFP_KERNEL); | |
415 | if (!pe) | |
416 | goto unlock; | |
417 | ||
418 | if (pdrv->policy_attr) { | |
419 | pe->node_type = get_policy_node_type(pdrv->policy_attr); | |
420 | if (!pe->node_type) | |
421 | goto unlock; | |
422 | } | |
423 | ||
424 | list_add_tail(&pe->entry, &stm_pdrv_head); | |
425 | pe->pdrv = pdrv; | |
426 | ||
427 | ret = 0; | |
428 | unlock: | |
429 | mutex_unlock(&stm_pdrv_mutex); | |
430 | ||
431 | if (ret) | |
432 | kfree(pe); | |
433 | ||
434 | return ret; | |
435 | } | |
436 | EXPORT_SYMBOL_GPL(stm_register_protocol); | |
437 | ||
438 | void stm_unregister_protocol(const struct stm_protocol_driver *pdrv) | |
439 | { | |
440 | struct stm_pdrv_entry *pe, *iter; | |
441 | ||
442 | mutex_lock(&stm_pdrv_mutex); | |
443 | ||
444 | list_for_each_entry_safe(pe, iter, &stm_pdrv_head, entry) { | |
445 | if (pe->pdrv == pdrv) { | |
446 | list_del(&pe->entry); | |
447 | ||
448 | if (pe->node_type) { | |
449 | kfree(pe->node_type->ct_attrs); | |
450 | kfree(pe->node_type); | |
451 | } | |
452 | kfree(pe); | |
453 | break; | |
454 | } | |
455 | } | |
456 | ||
457 | mutex_unlock(&stm_pdrv_mutex); | |
458 | } | |
459 | EXPORT_SYMBOL_GPL(stm_unregister_protocol); | |
460 | ||
461 | static bool stm_get_protocol(const struct stm_protocol_driver *pdrv) | |
462 | { | |
463 | return try_module_get(pdrv->owner); | |
464 | } | |
465 | ||
466 | void stm_put_protocol(const struct stm_protocol_driver *pdrv) | |
467 | { | |
468 | module_put(pdrv->owner); | |
469 | } | |
470 | ||
471 | int stm_lookup_protocol(const char *name, | |
472 | const struct stm_protocol_driver **pdrv, | |
473 | const struct config_item_type **node_type) | |
474 | { | |
475 | const struct stm_pdrv_entry *pe; | |
476 | ||
477 | mutex_lock(&stm_pdrv_mutex); | |
478 | ||
479 | pe = __stm_lookup_protocol(name); | |
480 | if (pe && pe->pdrv && stm_get_protocol(pe->pdrv)) { | |
481 | *pdrv = pe->pdrv; | |
482 | *node_type = pe->node_type; | |
483 | } | |
484 | ||
485 | mutex_unlock(&stm_pdrv_mutex); | |
486 | ||
487 | return pe ? 0 : -ENOENT; | |
488 | } | |
489 | ||
7bd1d409 AS |
490 | static int stm_char_open(struct inode *inode, struct file *file) |
491 | { | |
492 | struct stm_file *stmf; | |
493 | struct device *dev; | |
494 | unsigned int major = imajor(inode); | |
a0ebf519 | 495 | int err = -ENOMEM; |
7bd1d409 AS |
496 | |
497 | dev = class_find_device(&stm_class, NULL, &major, major_match); | |
498 | if (!dev) | |
499 | return -ENODEV; | |
500 | ||
501 | stmf = kzalloc(sizeof(*stmf), GFP_KERNEL); | |
502 | if (!stmf) | |
a0ebf519 | 503 | goto err_put_device; |
7bd1d409 | 504 | |
a0ebf519 | 505 | err = -ENODEV; |
cde4ad83 | 506 | stm_output_init(&stmf->output); |
7bd1d409 AS |
507 | stmf->stm = to_stm_device(dev); |
508 | ||
509 | if (!try_module_get(stmf->stm->owner)) | |
510 | goto err_free; | |
511 | ||
512 | file->private_data = stmf; | |
513 | ||
514 | return nonseekable_open(inode, file); | |
515 | ||
516 | err_free: | |
a0ebf519 JH |
517 | kfree(stmf); |
518 | err_put_device: | |
f7c81c71 AS |
519 | /* matches class_find_device() above */ |
520 | put_device(dev); | |
7bd1d409 AS |
521 | |
522 | return err; | |
523 | } | |
524 | ||
525 | static int stm_char_release(struct inode *inode, struct file *file) | |
526 | { | |
527 | struct stm_file *stmf = file->private_data; | |
cc842407 AS |
528 | struct stm_device *stm = stmf->stm; |
529 | ||
530 | if (stm->data->unlink) | |
531 | stm->data->unlink(stm->data, stmf->output.master, | |
532 | stmf->output.channel); | |
7bd1d409 | 533 | |
cc842407 | 534 | stm_output_free(stm, &stmf->output); |
f7c81c71 AS |
535 | |
536 | /* | |
537 | * matches the stm_char_open()'s | |
538 | * class_find_device() + try_module_get() | |
539 | */ | |
cc842407 | 540 | stm_put_device(stm); |
7bd1d409 AS |
541 | kfree(stmf); |
542 | ||
543 | return 0; | |
544 | } | |
545 | ||
cb6102bd AS |
546 | static int |
547 | stm_assign_first_policy(struct stm_device *stm, struct stm_output *output, | |
548 | char **ids, unsigned int width) | |
7bd1d409 | 549 | { |
cb6102bd AS |
550 | struct stp_policy_node *pn; |
551 | int err, n; | |
7bd1d409 | 552 | |
cb6102bd AS |
553 | /* |
554 | * On success, stp_policy_node_lookup() will return holding the | |
555 | * configfs subsystem mutex, which is then released in | |
556 | * stp_policy_node_put(). This allows the pdrv->output_open() in | |
557 | * stm_output_assign() to serialize against the attribute accessors. | |
558 | */ | |
559 | for (n = 0, pn = NULL; ids[n] && !pn; n++) | |
560 | pn = stp_policy_node_lookup(stm, ids[n]); | |
7bd1d409 | 561 | |
cb6102bd AS |
562 | if (!pn) |
563 | return -EINVAL; | |
7bd1d409 | 564 | |
cb6102bd | 565 | err = stm_output_assign(stm, width, pn, output); |
7bd1d409 | 566 | |
cb6102bd AS |
567 | stp_policy_node_put(pn); |
568 | ||
569 | return err; | |
7bd1d409 AS |
570 | } |
571 | ||
d279a380 AS |
572 | /** |
573 | * stm_data_write() - send the given payload as data packets | |
574 | * @data: stm driver's data | |
575 | * @m: STP master | |
576 | * @c: STP channel | |
577 | * @ts_first: timestamp the first packet | |
578 | * @buf: data payload buffer | |
579 | * @count: data payload size | |
580 | */ | |
581 | ssize_t notrace stm_data_write(struct stm_data *data, unsigned int m, | |
582 | unsigned int c, bool ts_first, const void *buf, | |
583 | size_t count) | |
7bd1d409 | 584 | { |
d279a380 | 585 | unsigned int flags = ts_first ? STP_PACKET_TIMESTAMPED : 0; |
7bd1d409 | 586 | ssize_t sz; |
d279a380 | 587 | size_t pos; |
7bd1d409 | 588 | |
d279a380 | 589 | for (pos = 0, sz = 0; pos < count; pos += sz) { |
7bd1d409 | 590 | sz = min_t(unsigned int, count - pos, 8); |
d279a380 AS |
591 | sz = data->packet(data, m, c, STP_PACKET_DATA, flags, sz, |
592 | &((u8 *)buf)[pos]); | |
593 | if (sz <= 0) | |
f8560a9b | 594 | break; |
d279a380 AS |
595 | |
596 | if (ts_first) { | |
597 | flags = 0; | |
598 | ts_first = false; | |
599 | } | |
7bd1d409 AS |
600 | } |
601 | ||
d279a380 AS |
602 | return sz < 0 ? sz : pos; |
603 | } | |
604 | EXPORT_SYMBOL_GPL(stm_data_write); | |
605 | ||
24c7bcb6 AS |
606 | static ssize_t notrace |
607 | stm_write(struct stm_device *stm, struct stm_output *output, | |
608 | unsigned int chan, const char *buf, size_t count) | |
d279a380 | 609 | { |
24c7bcb6 AS |
610 | int err; |
611 | ||
612 | /* stm->pdrv is serialized against policy_mutex */ | |
613 | if (!stm->pdrv) | |
614 | return -ENODEV; | |
d279a380 | 615 | |
24c7bcb6 AS |
616 | err = stm->pdrv->write(stm->data, output, chan, buf, count); |
617 | if (err < 0) | |
618 | return err; | |
f8560a9b | 619 | |
24c7bcb6 | 620 | return err; |
7bd1d409 AS |
621 | } |
622 | ||
623 | static ssize_t stm_char_write(struct file *file, const char __user *buf, | |
624 | size_t count, loff_t *ppos) | |
625 | { | |
626 | struct stm_file *stmf = file->private_data; | |
627 | struct stm_device *stm = stmf->stm; | |
628 | char *kbuf; | |
629 | int err; | |
630 | ||
f08b1826 AS |
631 | if (count + 1 > PAGE_SIZE) |
632 | count = PAGE_SIZE - 1; | |
633 | ||
7bd1d409 | 634 | /* |
cb6102bd AS |
635 | * If no m/c have been assigned to this writer up to this |
636 | * point, try to use the task name and "default" policy entries. | |
7bd1d409 AS |
637 | */ |
638 | if (!stmf->output.nr_chans) { | |
cb6102bd AS |
639 | char comm[sizeof(current->comm)]; |
640 | char *ids[] = { comm, "default", NULL }; | |
641 | ||
642 | get_task_comm(comm, current); | |
643 | ||
644 | err = stm_assign_first_policy(stmf->stm, &stmf->output, ids, 1); | |
7bd1d409 AS |
645 | /* |
646 | * EBUSY means that somebody else just assigned this | |
647 | * output, which is just fine for write() | |
648 | */ | |
cb6102bd | 649 | if (err) |
7bd1d409 AS |
650 | return err; |
651 | } | |
652 | ||
653 | kbuf = kmalloc(count + 1, GFP_KERNEL); | |
654 | if (!kbuf) | |
655 | return -ENOMEM; | |
656 | ||
657 | err = copy_from_user(kbuf, buf, count); | |
658 | if (err) { | |
659 | kfree(kbuf); | |
660 | return -EFAULT; | |
661 | } | |
662 | ||
8e0469a4 AS |
663 | pm_runtime_get_sync(&stm->dev); |
664 | ||
24c7bcb6 | 665 | count = stm_write(stm, &stmf->output, 0, kbuf, count); |
7bd1d409 | 666 | |
8e0469a4 AS |
667 | pm_runtime_mark_last_busy(&stm->dev); |
668 | pm_runtime_put_autosuspend(&stm->dev); | |
7bd1d409 AS |
669 | kfree(kbuf); |
670 | ||
671 | return count; | |
672 | } | |
673 | ||
8e0469a4 AS |
674 | static void stm_mmap_open(struct vm_area_struct *vma) |
675 | { | |
676 | struct stm_file *stmf = vma->vm_file->private_data; | |
677 | struct stm_device *stm = stmf->stm; | |
678 | ||
679 | pm_runtime_get(&stm->dev); | |
680 | } | |
681 | ||
682 | static void stm_mmap_close(struct vm_area_struct *vma) | |
683 | { | |
684 | struct stm_file *stmf = vma->vm_file->private_data; | |
685 | struct stm_device *stm = stmf->stm; | |
686 | ||
687 | pm_runtime_mark_last_busy(&stm->dev); | |
688 | pm_runtime_put_autosuspend(&stm->dev); | |
689 | } | |
690 | ||
691 | static const struct vm_operations_struct stm_mmap_vmops = { | |
692 | .open = stm_mmap_open, | |
693 | .close = stm_mmap_close, | |
694 | }; | |
695 | ||
7bd1d409 AS |
696 | static int stm_char_mmap(struct file *file, struct vm_area_struct *vma) |
697 | { | |
698 | struct stm_file *stmf = file->private_data; | |
699 | struct stm_device *stm = stmf->stm; | |
700 | unsigned long size, phys; | |
701 | ||
702 | if (!stm->data->mmio_addr) | |
703 | return -EOPNOTSUPP; | |
704 | ||
705 | if (vma->vm_pgoff) | |
706 | return -EINVAL; | |
707 | ||
708 | size = vma->vm_end - vma->vm_start; | |
709 | ||
710 | if (stmf->output.nr_chans * stm->data->sw_mmiosz != size) | |
711 | return -EINVAL; | |
712 | ||
713 | phys = stm->data->mmio_addr(stm->data, stmf->output.master, | |
714 | stmf->output.channel, | |
715 | stmf->output.nr_chans); | |
716 | ||
717 | if (!phys) | |
718 | return -EINVAL; | |
719 | ||
8e0469a4 AS |
720 | pm_runtime_get_sync(&stm->dev); |
721 | ||
7bd1d409 AS |
722 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
723 | vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP; | |
8e0469a4 | 724 | vma->vm_ops = &stm_mmap_vmops; |
7bd1d409 AS |
725 | vm_iomap_memory(vma, phys, size); |
726 | ||
727 | return 0; | |
728 | } | |
729 | ||
730 | static int stm_char_policy_set_ioctl(struct stm_file *stmf, void __user *arg) | |
731 | { | |
732 | struct stm_device *stm = stmf->stm; | |
733 | struct stp_policy_id *id; | |
cb6102bd | 734 | char *ids[] = { NULL, NULL }; |
7bd1d409 AS |
735 | int ret = -EINVAL; |
736 | u32 size; | |
737 | ||
738 | if (stmf->output.nr_chans) | |
739 | return -EBUSY; | |
740 | ||
741 | if (copy_from_user(&size, arg, sizeof(size))) | |
742 | return -EFAULT; | |
743 | ||
71c488f3 | 744 | if (size < sizeof(*id) || size >= PATH_MAX + sizeof(*id)) |
7bd1d409 AS |
745 | return -EINVAL; |
746 | ||
747 | /* | |
748 | * size + 1 to make sure the .id string at the bottom is terminated, | |
749 | * which is also why memdup_user() is not useful here | |
750 | */ | |
751 | id = kzalloc(size + 1, GFP_KERNEL); | |
752 | if (!id) | |
753 | return -ENOMEM; | |
754 | ||
755 | if (copy_from_user(id, arg, size)) { | |
756 | ret = -EFAULT; | |
757 | goto err_free; | |
758 | } | |
759 | ||
760 | if (id->__reserved_0 || id->__reserved_1) | |
761 | goto err_free; | |
762 | ||
763 | if (id->width < 1 || | |
764 | id->width > PAGE_SIZE / stm->data->sw_mmiosz) | |
765 | goto err_free; | |
766 | ||
cb6102bd AS |
767 | ids[0] = id->id; |
768 | ret = stm_assign_first_policy(stmf->stm, &stmf->output, ids, | |
769 | id->width); | |
7bd1d409 AS |
770 | if (ret) |
771 | goto err_free; | |
772 | ||
7bd1d409 AS |
773 | if (stm->data->link) |
774 | ret = stm->data->link(stm->data, stmf->output.master, | |
775 | stmf->output.channel); | |
776 | ||
f7c81c71 | 777 | if (ret) |
7bd1d409 | 778 | stm_output_free(stmf->stm, &stmf->output); |
7bd1d409 AS |
779 | |
780 | err_free: | |
781 | kfree(id); | |
782 | ||
783 | return ret; | |
784 | } | |
785 | ||
786 | static int stm_char_policy_get_ioctl(struct stm_file *stmf, void __user *arg) | |
787 | { | |
788 | struct stp_policy_id id = { | |
789 | .size = sizeof(id), | |
790 | .master = stmf->output.master, | |
791 | .channel = stmf->output.channel, | |
792 | .width = stmf->output.nr_chans, | |
793 | .__reserved_0 = 0, | |
794 | .__reserved_1 = 0, | |
795 | }; | |
796 | ||
797 | return copy_to_user(arg, &id, id.size) ? -EFAULT : 0; | |
798 | } | |
799 | ||
800 | static long | |
801 | stm_char_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
802 | { | |
803 | struct stm_file *stmf = file->private_data; | |
804 | struct stm_data *stm_data = stmf->stm->data; | |
805 | int err = -ENOTTY; | |
806 | u64 options; | |
807 | ||
808 | switch (cmd) { | |
809 | case STP_POLICY_ID_SET: | |
810 | err = stm_char_policy_set_ioctl(stmf, (void __user *)arg); | |
811 | if (err) | |
812 | return err; | |
813 | ||
814 | return stm_char_policy_get_ioctl(stmf, (void __user *)arg); | |
815 | ||
816 | case STP_POLICY_ID_GET: | |
817 | return stm_char_policy_get_ioctl(stmf, (void __user *)arg); | |
818 | ||
819 | case STP_SET_OPTIONS: | |
820 | if (copy_from_user(&options, (u64 __user *)arg, sizeof(u64))) | |
821 | return -EFAULT; | |
822 | ||
823 | if (stm_data->set_options) | |
824 | err = stm_data->set_options(stm_data, | |
825 | stmf->output.master, | |
826 | stmf->output.channel, | |
827 | stmf->output.nr_chans, | |
828 | options); | |
829 | ||
830 | break; | |
831 | default: | |
832 | break; | |
833 | } | |
834 | ||
835 | return err; | |
836 | } | |
837 | ||
838 | #ifdef CONFIG_COMPAT | |
839 | static long | |
840 | stm_char_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
841 | { | |
842 | return stm_char_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); | |
843 | } | |
844 | #else | |
845 | #define stm_char_compat_ioctl NULL | |
846 | #endif | |
847 | ||
848 | static const struct file_operations stm_fops = { | |
849 | .open = stm_char_open, | |
850 | .release = stm_char_release, | |
851 | .write = stm_char_write, | |
852 | .mmap = stm_char_mmap, | |
853 | .unlocked_ioctl = stm_char_ioctl, | |
854 | .compat_ioctl = stm_char_compat_ioctl, | |
855 | .llseek = no_llseek, | |
856 | }; | |
857 | ||
858 | static void stm_device_release(struct device *dev) | |
859 | { | |
860 | struct stm_device *stm = to_stm_device(dev); | |
861 | ||
b5e2ced9 | 862 | vfree(stm); |
7bd1d409 AS |
863 | } |
864 | ||
865 | int stm_register_device(struct device *parent, struct stm_data *stm_data, | |
866 | struct module *owner) | |
867 | { | |
868 | struct stm_device *stm; | |
869 | unsigned int nmasters; | |
870 | int err = -ENOMEM; | |
871 | ||
872 | if (!stm_core_up) | |
873 | return -EPROBE_DEFER; | |
874 | ||
875 | if (!stm_data->packet || !stm_data->sw_nchannels) | |
876 | return -EINVAL; | |
877 | ||
7b3bb0e7 | 878 | nmasters = stm_data->sw_end - stm_data->sw_start + 1; |
b5e2ced9 | 879 | stm = vzalloc(sizeof(*stm) + nmasters * sizeof(void *)); |
7bd1d409 AS |
880 | if (!stm) |
881 | return -ENOMEM; | |
882 | ||
883 | stm->major = register_chrdev(0, stm_data->name, &stm_fops); | |
884 | if (stm->major < 0) | |
885 | goto err_free; | |
886 | ||
887 | device_initialize(&stm->dev); | |
888 | stm->dev.devt = MKDEV(stm->major, 0); | |
889 | stm->dev.class = &stm_class; | |
890 | stm->dev.parent = parent; | |
891 | stm->dev.release = stm_device_release; | |
892 | ||
c74f7e82 | 893 | mutex_init(&stm->link_mutex); |
7bd1d409 AS |
894 | spin_lock_init(&stm->link_lock); |
895 | INIT_LIST_HEAD(&stm->link_list); | |
896 | ||
389b6699 | 897 | /* initialize the object before it is accessible via sysfs */ |
7bd1d409 AS |
898 | spin_lock_init(&stm->mc_lock); |
899 | mutex_init(&stm->policy_mutex); | |
900 | stm->sw_nmasters = nmasters; | |
901 | stm->owner = owner; | |
902 | stm->data = stm_data; | |
903 | stm_data->stm = stm; | |
904 | ||
389b6699 AS |
905 | err = kobject_set_name(&stm->dev.kobj, "%s", stm_data->name); |
906 | if (err) | |
907 | goto err_device; | |
908 | ||
909 | err = device_add(&stm->dev); | |
910 | if (err) | |
911 | goto err_device; | |
912 | ||
8e0469a4 AS |
913 | /* |
914 | * Use delayed autosuspend to avoid bouncing back and forth | |
915 | * on recurring character device writes, with the initial | |
916 | * delay time of 2 seconds. | |
917 | */ | |
918 | pm_runtime_no_callbacks(&stm->dev); | |
919 | pm_runtime_use_autosuspend(&stm->dev); | |
920 | pm_runtime_set_autosuspend_delay(&stm->dev, 2000); | |
921 | pm_runtime_set_suspended(&stm->dev); | |
922 | pm_runtime_enable(&stm->dev); | |
923 | ||
7bd1d409 AS |
924 | return 0; |
925 | ||
926 | err_device: | |
cbe4a61d AS |
927 | unregister_chrdev(stm->major, stm_data->name); |
928 | ||
f7c81c71 | 929 | /* matches device_initialize() above */ |
7bd1d409 AS |
930 | put_device(&stm->dev); |
931 | err_free: | |
b5e2ced9 | 932 | vfree(stm); |
7bd1d409 AS |
933 | |
934 | return err; | |
935 | } | |
936 | EXPORT_SYMBOL_GPL(stm_register_device); | |
937 | ||
b4ca34aa AS |
938 | static int __stm_source_link_drop(struct stm_source_device *src, |
939 | struct stm_device *stm); | |
7bd1d409 AS |
940 | |
941 | void stm_unregister_device(struct stm_data *stm_data) | |
942 | { | |
943 | struct stm_device *stm = stm_data->stm; | |
944 | struct stm_source_device *src, *iter; | |
b4ca34aa | 945 | int i, ret; |
7bd1d409 | 946 | |
8e0469a4 AS |
947 | pm_runtime_dont_use_autosuspend(&stm->dev); |
948 | pm_runtime_disable(&stm->dev); | |
949 | ||
c74f7e82 | 950 | mutex_lock(&stm->link_mutex); |
7bd1d409 | 951 | list_for_each_entry_safe(src, iter, &stm->link_list, link_entry) { |
b4ca34aa AS |
952 | ret = __stm_source_link_drop(src, stm); |
953 | /* | |
954 | * src <-> stm link must not change under the same | |
955 | * stm::link_mutex, so complain loudly if it has; | |
956 | * also in this situation ret!=0 means this src is | |
957 | * not connected to this stm and it should be otherwise | |
958 | * safe to proceed with the tear-down of stm. | |
959 | */ | |
960 | WARN_ON_ONCE(ret); | |
7bd1d409 | 961 | } |
c74f7e82 | 962 | mutex_unlock(&stm->link_mutex); |
7bd1d409 AS |
963 | |
964 | synchronize_srcu(&stm_source_srcu); | |
965 | ||
966 | unregister_chrdev(stm->major, stm_data->name); | |
967 | ||
968 | mutex_lock(&stm->policy_mutex); | |
969 | if (stm->policy) | |
970 | stp_policy_unbind(stm->policy); | |
971 | mutex_unlock(&stm->policy_mutex); | |
972 | ||
73a3ed19 | 973 | for (i = stm->data->sw_start; i <= stm->data->sw_end; i++) |
7bd1d409 AS |
974 | stp_master_free(stm, i); |
975 | ||
976 | device_unregister(&stm->dev); | |
977 | stm_data->stm = NULL; | |
978 | } | |
979 | EXPORT_SYMBOL_GPL(stm_unregister_device); | |
980 | ||
c74f7e82 AS |
981 | /* |
982 | * stm::link_list access serialization uses a spinlock and a mutex; holding | |
983 | * either of them guarantees that the list is stable; modification requires | |
984 | * holding both of them. | |
985 | * | |
986 | * Lock ordering is as follows: | |
987 | * stm::link_mutex | |
988 | * stm::link_lock | |
989 | * src::link_lock | |
990 | */ | |
991 | ||
7bd1d409 AS |
992 | /** |
993 | * stm_source_link_add() - connect an stm_source device to an stm device | |
994 | * @src: stm_source device | |
995 | * @stm: stm device | |
996 | * | |
997 | * This function establishes a link from stm_source to an stm device so that | |
998 | * the former can send out trace data to the latter. | |
999 | * | |
1000 | * Return: 0 on success, -errno otherwise. | |
1001 | */ | |
1002 | static int stm_source_link_add(struct stm_source_device *src, | |
1003 | struct stm_device *stm) | |
1004 | { | |
cb6102bd AS |
1005 | char *ids[] = { NULL, "default", NULL }; |
1006 | int err = -ENOMEM; | |
7bd1d409 | 1007 | |
c74f7e82 | 1008 | mutex_lock(&stm->link_mutex); |
7bd1d409 AS |
1009 | spin_lock(&stm->link_lock); |
1010 | spin_lock(&src->link_lock); | |
1011 | ||
1012 | /* src->link is dereferenced under stm_source_srcu but not the list */ | |
1013 | rcu_assign_pointer(src->link, stm); | |
1014 | list_add_tail(&src->link_entry, &stm->link_list); | |
1015 | ||
1016 | spin_unlock(&src->link_lock); | |
1017 | spin_unlock(&stm->link_lock); | |
c74f7e82 | 1018 | mutex_unlock(&stm->link_mutex); |
7bd1d409 | 1019 | |
cb6102bd AS |
1020 | ids[0] = kstrdup(src->data->name, GFP_KERNEL); |
1021 | if (!ids[0]) | |
1022 | goto fail_detach; | |
7bd1d409 | 1023 | |
cb6102bd AS |
1024 | err = stm_assign_first_policy(stm, &src->output, ids, |
1025 | src->data->nr_chans); | |
1026 | kfree(ids[0]); | |
7bd1d409 AS |
1027 | |
1028 | if (err) | |
1029 | goto fail_detach; | |
1030 | ||
1031 | /* this is to notify the STM device that a new link has been made */ | |
1032 | if (stm->data->link) | |
1033 | err = stm->data->link(stm->data, src->output.master, | |
1034 | src->output.channel); | |
1035 | ||
1036 | if (err) | |
1037 | goto fail_free_output; | |
1038 | ||
1039 | /* this is to let the source carry out all necessary preparations */ | |
1040 | if (src->data->link) | |
1041 | src->data->link(src->data); | |
1042 | ||
1043 | return 0; | |
1044 | ||
1045 | fail_free_output: | |
1046 | stm_output_free(stm, &src->output); | |
7bd1d409 AS |
1047 | |
1048 | fail_detach: | |
c74f7e82 | 1049 | mutex_lock(&stm->link_mutex); |
7bd1d409 AS |
1050 | spin_lock(&stm->link_lock); |
1051 | spin_lock(&src->link_lock); | |
1052 | ||
1053 | rcu_assign_pointer(src->link, NULL); | |
1054 | list_del_init(&src->link_entry); | |
1055 | ||
1056 | spin_unlock(&src->link_lock); | |
1057 | spin_unlock(&stm->link_lock); | |
c74f7e82 | 1058 | mutex_unlock(&stm->link_mutex); |
7bd1d409 AS |
1059 | |
1060 | return err; | |
1061 | } | |
1062 | ||
1063 | /** | |
1064 | * __stm_source_link_drop() - detach stm_source from an stm device | |
1065 | * @src: stm_source device | |
1066 | * @stm: stm device | |
1067 | * | |
1068 | * If @stm is @src::link, disconnect them from one another and put the | |
1069 | * reference on the @stm device. | |
1070 | * | |
c74f7e82 | 1071 | * Caller must hold stm::link_mutex. |
7bd1d409 | 1072 | */ |
b4ca34aa AS |
1073 | static int __stm_source_link_drop(struct stm_source_device *src, |
1074 | struct stm_device *stm) | |
7bd1d409 | 1075 | { |
0df771de | 1076 | struct stm_device *link; |
b4ca34aa | 1077 | int ret = 0; |
0df771de | 1078 | |
c74f7e82 AS |
1079 | lockdep_assert_held(&stm->link_mutex); |
1080 | ||
c74f7e82 AS |
1081 | /* for stm::link_list modification, we hold both mutex and spinlock */ |
1082 | spin_lock(&stm->link_lock); | |
7bd1d409 | 1083 | spin_lock(&src->link_lock); |
0df771de | 1084 | link = srcu_dereference_check(src->link, &stm_source_srcu, 1); |
b4ca34aa AS |
1085 | |
1086 | /* | |
1087 | * The linked device may have changed since we last looked, because | |
1088 | * we weren't holding the src::link_lock back then; if this is the | |
1089 | * case, tell the caller to retry. | |
1090 | */ | |
1091 | if (link != stm) { | |
1092 | ret = -EAGAIN; | |
1810f2c4 | 1093 | goto unlock; |
b4ca34aa | 1094 | } |
7bd1d409 | 1095 | |
0df771de | 1096 | stm_output_free(link, &src->output); |
7bd1d409 | 1097 | list_del_init(&src->link_entry); |
8e0469a4 AS |
1098 | pm_runtime_mark_last_busy(&link->dev); |
1099 | pm_runtime_put_autosuspend(&link->dev); | |
7bd1d409 | 1100 | /* matches stm_find_device() from stm_source_link_store() */ |
0df771de | 1101 | stm_put_device(link); |
7bd1d409 AS |
1102 | rcu_assign_pointer(src->link, NULL); |
1103 | ||
1810f2c4 | 1104 | unlock: |
7bd1d409 | 1105 | spin_unlock(&src->link_lock); |
c74f7e82 | 1106 | spin_unlock(&stm->link_lock); |
b4ca34aa | 1107 | |
cc842407 AS |
1108 | /* |
1109 | * Call the unlink callbacks for both source and stm, when we know | |
1110 | * that we have actually performed the unlinking. | |
1111 | */ | |
1112 | if (!ret) { | |
1113 | if (src->data->unlink) | |
1114 | src->data->unlink(src->data); | |
1115 | ||
1116 | if (stm->data->unlink) | |
1117 | stm->data->unlink(stm->data, src->output.master, | |
1118 | src->output.channel); | |
1119 | } | |
b4ca34aa AS |
1120 | |
1121 | return ret; | |
7bd1d409 AS |
1122 | } |
1123 | ||
1124 | /** | |
1125 | * stm_source_link_drop() - detach stm_source from its stm device | |
1126 | * @src: stm_source device | |
1127 | * | |
1128 | * Unlinking means disconnecting from source's STM device; after this | |
1129 | * writes will be unsuccessful until it is linked to a new STM device. | |
1130 | * | |
1131 | * This will happen on "stm_source_link" sysfs attribute write to undo | |
1132 | * the existing link (if any), or on linked STM device's de-registration. | |
1133 | */ | |
1134 | static void stm_source_link_drop(struct stm_source_device *src) | |
1135 | { | |
1136 | struct stm_device *stm; | |
b4ca34aa | 1137 | int idx, ret; |
7bd1d409 | 1138 | |
b4ca34aa | 1139 | retry: |
7bd1d409 | 1140 | idx = srcu_read_lock(&stm_source_srcu); |
b4ca34aa AS |
1141 | /* |
1142 | * The stm device will be valid for the duration of this | |
1143 | * read section, but the link may change before we grab | |
1144 | * the src::link_lock in __stm_source_link_drop(). | |
1145 | */ | |
7bd1d409 AS |
1146 | stm = srcu_dereference(src->link, &stm_source_srcu); |
1147 | ||
b4ca34aa | 1148 | ret = 0; |
7bd1d409 | 1149 | if (stm) { |
c74f7e82 | 1150 | mutex_lock(&stm->link_mutex); |
b4ca34aa | 1151 | ret = __stm_source_link_drop(src, stm); |
c74f7e82 | 1152 | mutex_unlock(&stm->link_mutex); |
7bd1d409 AS |
1153 | } |
1154 | ||
1155 | srcu_read_unlock(&stm_source_srcu, idx); | |
b4ca34aa AS |
1156 | |
1157 | /* if it did change, retry */ | |
1158 | if (ret == -EAGAIN) | |
1159 | goto retry; | |
7bd1d409 AS |
1160 | } |
1161 | ||
1162 | static ssize_t stm_source_link_show(struct device *dev, | |
1163 | struct device_attribute *attr, | |
1164 | char *buf) | |
1165 | { | |
1166 | struct stm_source_device *src = to_stm_source_device(dev); | |
1167 | struct stm_device *stm; | |
1168 | int idx, ret; | |
1169 | ||
1170 | idx = srcu_read_lock(&stm_source_srcu); | |
1171 | stm = srcu_dereference(src->link, &stm_source_srcu); | |
1172 | ret = sprintf(buf, "%s\n", | |
1173 | stm ? dev_name(&stm->dev) : "<none>"); | |
1174 | srcu_read_unlock(&stm_source_srcu, idx); | |
1175 | ||
1176 | return ret; | |
1177 | } | |
1178 | ||
1179 | static ssize_t stm_source_link_store(struct device *dev, | |
1180 | struct device_attribute *attr, | |
1181 | const char *buf, size_t count) | |
1182 | { | |
1183 | struct stm_source_device *src = to_stm_source_device(dev); | |
1184 | struct stm_device *link; | |
1185 | int err; | |
1186 | ||
1187 | stm_source_link_drop(src); | |
1188 | ||
1189 | link = stm_find_device(buf); | |
1190 | if (!link) | |
1191 | return -EINVAL; | |
1192 | ||
8e0469a4 AS |
1193 | pm_runtime_get(&link->dev); |
1194 | ||
7bd1d409 | 1195 | err = stm_source_link_add(src, link); |
f7c81c71 | 1196 | if (err) { |
8e0469a4 | 1197 | pm_runtime_put_autosuspend(&link->dev); |
f7c81c71 | 1198 | /* matches the stm_find_device() above */ |
7bd1d409 | 1199 | stm_put_device(link); |
f7c81c71 | 1200 | } |
7bd1d409 AS |
1201 | |
1202 | return err ? : count; | |
1203 | } | |
1204 | ||
1205 | static DEVICE_ATTR_RW(stm_source_link); | |
1206 | ||
1207 | static struct attribute *stm_source_attrs[] = { | |
1208 | &dev_attr_stm_source_link.attr, | |
1209 | NULL, | |
1210 | }; | |
1211 | ||
1212 | ATTRIBUTE_GROUPS(stm_source); | |
1213 | ||
1214 | static struct class stm_source_class = { | |
1215 | .name = "stm_source", | |
1216 | .dev_groups = stm_source_groups, | |
1217 | }; | |
1218 | ||
1219 | static void stm_source_device_release(struct device *dev) | |
1220 | { | |
1221 | struct stm_source_device *src = to_stm_source_device(dev); | |
1222 | ||
1223 | kfree(src); | |
1224 | } | |
1225 | ||
1226 | /** | |
1227 | * stm_source_register_device() - register an stm_source device | |
1228 | * @parent: parent device | |
1229 | * @data: device description structure | |
1230 | * | |
1231 | * This will create a device of stm_source class that can write | |
1232 | * data to an stm device once linked. | |
1233 | * | |
1234 | * Return: 0 on success, -errno otherwise. | |
1235 | */ | |
1236 | int stm_source_register_device(struct device *parent, | |
1237 | struct stm_source_data *data) | |
1238 | { | |
1239 | struct stm_source_device *src; | |
1240 | int err; | |
1241 | ||
1242 | if (!stm_core_up) | |
1243 | return -EPROBE_DEFER; | |
1244 | ||
1245 | src = kzalloc(sizeof(*src), GFP_KERNEL); | |
1246 | if (!src) | |
1247 | return -ENOMEM; | |
1248 | ||
1249 | device_initialize(&src->dev); | |
1250 | src->dev.class = &stm_source_class; | |
1251 | src->dev.parent = parent; | |
1252 | src->dev.release = stm_source_device_release; | |
1253 | ||
1254 | err = kobject_set_name(&src->dev.kobj, "%s", data->name); | |
1255 | if (err) | |
1256 | goto err; | |
1257 | ||
8e0469a4 AS |
1258 | pm_runtime_no_callbacks(&src->dev); |
1259 | pm_runtime_forbid(&src->dev); | |
1260 | ||
7bd1d409 AS |
1261 | err = device_add(&src->dev); |
1262 | if (err) | |
1263 | goto err; | |
1264 | ||
cde4ad83 | 1265 | stm_output_init(&src->output); |
7bd1d409 AS |
1266 | spin_lock_init(&src->link_lock); |
1267 | INIT_LIST_HEAD(&src->link_entry); | |
1268 | src->data = data; | |
1269 | data->src = src; | |
1270 | ||
1271 | return 0; | |
1272 | ||
1273 | err: | |
1274 | put_device(&src->dev); | |
1275 | kfree(src); | |
1276 | ||
1277 | return err; | |
1278 | } | |
1279 | EXPORT_SYMBOL_GPL(stm_source_register_device); | |
1280 | ||
1281 | /** | |
1282 | * stm_source_unregister_device() - unregister an stm_source device | |
1283 | * @data: device description that was used to register the device | |
1284 | * | |
1285 | * This will remove a previously created stm_source device from the system. | |
1286 | */ | |
1287 | void stm_source_unregister_device(struct stm_source_data *data) | |
1288 | { | |
1289 | struct stm_source_device *src = data->src; | |
1290 | ||
1291 | stm_source_link_drop(src); | |
1292 | ||
fd085bb1 | 1293 | device_unregister(&src->dev); |
7bd1d409 AS |
1294 | } |
1295 | EXPORT_SYMBOL_GPL(stm_source_unregister_device); | |
1296 | ||
9dfed80d CZ |
1297 | int notrace stm_source_write(struct stm_source_data *data, |
1298 | unsigned int chan, | |
1299 | const char *buf, size_t count) | |
7bd1d409 AS |
1300 | { |
1301 | struct stm_source_device *src = data->src; | |
1302 | struct stm_device *stm; | |
1303 | int idx; | |
1304 | ||
1305 | if (!src->output.nr_chans) | |
1306 | return -ENODEV; | |
1307 | ||
1308 | if (chan >= src->output.nr_chans) | |
1309 | return -EINVAL; | |
1310 | ||
1311 | idx = srcu_read_lock(&stm_source_srcu); | |
1312 | ||
1313 | stm = srcu_dereference(src->link, &stm_source_srcu); | |
1314 | if (stm) | |
24c7bcb6 | 1315 | count = stm_write(stm, &src->output, chan, buf, count); |
7bd1d409 AS |
1316 | else |
1317 | count = -ENODEV; | |
1318 | ||
1319 | srcu_read_unlock(&stm_source_srcu, idx); | |
1320 | ||
1321 | return count; | |
1322 | } | |
1323 | EXPORT_SYMBOL_GPL(stm_source_write); | |
1324 | ||
1325 | static int __init stm_core_init(void) | |
1326 | { | |
1327 | int err; | |
1328 | ||
1329 | err = class_register(&stm_class); | |
1330 | if (err) | |
1331 | return err; | |
1332 | ||
1333 | err = class_register(&stm_source_class); | |
1334 | if (err) | |
1335 | goto err_stm; | |
1336 | ||
1337 | err = stp_configfs_init(); | |
1338 | if (err) | |
1339 | goto err_src; | |
1340 | ||
1341 | init_srcu_struct(&stm_source_srcu); | |
c7fd62bc AS |
1342 | INIT_LIST_HEAD(&stm_pdrv_head); |
1343 | mutex_init(&stm_pdrv_mutex); | |
7bd1d409 | 1344 | |
24c7bcb6 AS |
1345 | /* |
1346 | * So as to not confuse existing users with a requirement | |
1347 | * to load yet another module, do it here. | |
1348 | */ | |
1349 | if (IS_ENABLED(CONFIG_STM_PROTO_BASIC)) | |
1350 | (void)request_module_nowait("stm_p_basic"); | |
7bd1d409 AS |
1351 | stm_core_up++; |
1352 | ||
1353 | return 0; | |
1354 | ||
1355 | err_src: | |
1356 | class_unregister(&stm_source_class); | |
1357 | err_stm: | |
1358 | class_unregister(&stm_class); | |
1359 | ||
1360 | return err; | |
1361 | } | |
1362 | ||
1363 | module_init(stm_core_init); | |
1364 | ||
1365 | static void __exit stm_core_exit(void) | |
1366 | { | |
1367 | cleanup_srcu_struct(&stm_source_srcu); | |
1368 | class_unregister(&stm_source_class); | |
1369 | class_unregister(&stm_class); | |
1370 | stp_configfs_exit(); | |
1371 | } | |
1372 | ||
1373 | module_exit(stm_core_exit); | |
1374 | ||
1375 | MODULE_LICENSE("GPL v2"); | |
1376 | MODULE_DESCRIPTION("System Trace Module device class"); | |
1377 | MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>"); |