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