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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 | ||
7bd1d409 AS |
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 | ||
6cda08a2 | 112 | dev = class_find_device_by_name(&stm_class, buf); |
7bd1d409 AS |
113 | if (!dev) |
114 | return NULL; | |
115 | ||
116 | stm = to_stm_device(dev); | |
117 | if (!try_module_get(stm->owner)) { | |
f7c81c71 | 118 | /* matches class_find_device() above */ |
7bd1d409 AS |
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 | |
f7c81c71 | 131 | * stm_find_device() or stm_char_open(). |
7bd1d409 AS |
132 | */ |
133 | void stm_put_device(struct stm_device *stm) | |
134 | { | |
135 | module_put(stm->owner); | |
136 | put_device(&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; | |
7bd1d409 | 162 | |
51e0f227 AS |
163 | master = kzalloc(struct_size(master, chan_map, |
164 | BITS_TO_LONGS(stm->data->sw_nchannels)), | |
165 | GFP_ATOMIC); | |
7bd1d409 AS |
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(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, output->master); | |
189 | ||
cde4ad83 AS |
190 | lockdep_assert_held(&stm->mc_lock); |
191 | lockdep_assert_held(&output->lock); | |
192 | ||
7bd1d409 AS |
193 | if (WARN_ON_ONCE(master->nr_free < output->nr_chans)) |
194 | return; | |
195 | ||
196 | bitmap_allocate_region(&master->chan_map[0], 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, output->master); | |
206 | ||
cde4ad83 AS |
207 | lockdep_assert_held(&stm->mc_lock); |
208 | lockdep_assert_held(&output->lock); | |
209 | ||
7bd1d409 AS |
210 | bitmap_release_region(&master->chan_map[0], output->channel, |
211 | ilog2(output->nr_chans)); | |
212 | ||
7bd1d409 | 213 | master->nr_free += output->nr_chans; |
ee496da4 | 214 | output->nr_chans = 0; |
7bd1d409 AS |
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(bitmap, end + 1, 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; | |
a1d75dad ZJ |
239 | |
240 | /* step over [pos..pos+i) to continue search */ | |
241 | pos += i; | |
7bd1d409 AS |
242 | } |
243 | ||
244 | return -1; | |
245 | } | |
246 | ||
f45f40ad | 247 | static int |
7bd1d409 AS |
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, midx)) { | |
258 | err = stp_master_alloc(stm, midx); | |
259 | if (err) | |
260 | return err; | |
261 | } | |
262 | ||
263 | master = stm_master(stm, midx); | |
264 | ||
265 | if (!master->nr_free) | |
266 | continue; | |
267 | ||
268 | pos = find_free_channels(master->chan_map, *cstart, 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 | ||
cb6102bd AS |
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, &midx, &mend, &cidx, &cend); | |
7bd1d409 AS |
300 | |
301 | spin_lock(&stm->mc_lock); | |
cde4ad83 | 302 | spin_lock(&output->lock); |
7bd1d409 AS |
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, &midx, mend, &cidx, cend); | |
f45f40ad | 308 | if (ret < 0) |
7bd1d409 AS |
309 | goto unlock; |
310 | ||
311 | output->master = midx; | |
312 | output->channel = cidx; | |
313 | output->nr_chans = width; | |
c7fd62bc AS |
314 | if (stm->pdrv->output_open) { |
315 | void *priv = stp_policy_node_priv(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 | ||
7bd1d409 AS |
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: | |
c7fd62bc AS |
331 | if (ret) |
332 | output->nr_chans = 0; | |
333 | ||
cde4ad83 | 334 | spin_unlock(&output->lock); |
7bd1d409 AS |
335 | spin_unlock(&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(&stm->mc_lock); | |
cde4ad83 | 343 | spin_lock(&output->lock); |
7bd1d409 AS |
344 | if (output->nr_chans) |
345 | stm_output_disclaim(stm, output); | |
c7fd62bc AS |
346 | if (stm->pdrv && stm->pdrv->output_close) |
347 | stm->pdrv->output_close(output); | |
cde4ad83 | 348 | spin_unlock(&output->lock); |
7bd1d409 AS |
349 | spin_unlock(&stm->mc_lock); |
350 | } | |
351 | ||
cde4ad83 AS |
352 | static void stm_output_init(struct stm_output *output) |
353 | { | |
354 | spin_lock_init(&output->lock); | |
355 | } | |
356 | ||
7bd1d409 AS |
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 | ||
c7fd62bc AS |
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(pdrv->name)) { | |
405 | ret = -EEXIST; | |
406 | goto unlock; | |
407 | } | |
408 | ||
409 | pe = kzalloc(sizeof(*pe), GFP_KERNEL); | |
410 | if (!pe) | |
411 | goto unlock; | |
412 | ||
413 | if (pdrv->policy_attr) { | |
414 | pe->node_type = get_policy_node_type(pdrv->policy_attr); | |
415 | if (!pe->node_type) | |
416 | goto unlock; | |
417 | } | |
418 | ||
419 | list_add_tail(&pe->entry, &stm_pdrv_head); | |
420 | pe->pdrv = pdrv; | |
421 | ||
422 | ret = 0; | |
423 | unlock: | |
424 | mutex_unlock(&stm_pdrv_mutex); | |
425 | ||
426 | if (ret) | |
427 | kfree(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(&pe->entry); | |
442 | ||
443 | if (pe->node_type) { | |
444 | kfree(pe->node_type->ct_attrs); | |
445 | kfree(pe->node_type); | |
446 | } | |
447 | kfree(pe); | |
448 | break; | |
449 | } | |
450 | } | |
451 | ||
452 | mutex_unlock(&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(pdrv->owner); | |
459 | } | |
460 | ||
461 | void stm_put_protocol(const struct stm_protocol_driver *pdrv) | |
462 | { | |
463 | module_put(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(pe->pdrv)) { | |
476 | *pdrv = pe->pdrv; | |
477 | *node_type = pe->node_type; | |
478 | } | |
479 | ||
480 | mutex_unlock(&stm_pdrv_mutex); | |
481 | ||
482 | return pe ? 0 : -ENOENT; | |
483 | } | |
484 | ||
7bd1d409 AS |
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); | |
a0ebf519 | 490 | int err = -ENOMEM; |
7bd1d409 AS |
491 | |
492 | dev = class_find_device(&stm_class, NULL, &major, major_match); | |
493 | if (!dev) | |
494 | return -ENODEV; | |
495 | ||
496 | stmf = kzalloc(sizeof(*stmf), GFP_KERNEL); | |
497 | if (!stmf) | |
a0ebf519 | 498 | goto err_put_device; |
7bd1d409 | 499 | |
a0ebf519 | 500 | err = -ENODEV; |
cde4ad83 | 501 | stm_output_init(&stmf->output); |
7bd1d409 AS |
502 | stmf->stm = to_stm_device(dev); |
503 | ||
504 | if (!try_module_get(stmf->stm->owner)) | |
505 | goto err_free; | |
506 | ||
507 | file->private_data = stmf; | |
508 | ||
509 | return nonseekable_open(inode, file); | |
510 | ||
511 | err_free: | |
a0ebf519 JH |
512 | kfree(stmf); |
513 | err_put_device: | |
f7c81c71 AS |
514 | /* matches class_find_device() above */ |
515 | put_device(dev); | |
7bd1d409 AS |
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; | |
cc842407 AS |
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); | |
7bd1d409 | 528 | |
cc842407 | 529 | stm_output_free(stm, &stmf->output); |
f7c81c71 AS |
530 | |
531 | /* | |
532 | * matches the stm_char_open()'s | |
533 | * class_find_device() + try_module_get() | |
534 | */ | |
cc842407 | 535 | stm_put_device(stm); |
7bd1d409 AS |
536 | kfree(stmf); |
537 | ||
538 | return 0; | |
539 | } | |
540 | ||
cb6102bd AS |
541 | static int |
542 | stm_assign_first_policy(struct stm_device *stm, struct stm_output *output, | |
543 | char **ids, unsigned int width) | |
7bd1d409 | 544 | { |
cb6102bd AS |
545 | struct stp_policy_node *pn; |
546 | int err, n; | |
7bd1d409 | 547 | |
cb6102bd AS |
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, ids[n]); | |
7bd1d409 | 556 | |
cb6102bd AS |
557 | if (!pn) |
558 | return -EINVAL; | |
7bd1d409 | 559 | |
cb6102bd | 560 | err = stm_output_assign(stm, width, pn, output); |
7bd1d409 | 561 | |
cb6102bd AS |
562 | stp_policy_node_put(pn); |
563 | ||
564 | return err; | |
7bd1d409 AS |
565 | } |
566 | ||
d279a380 AS |
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) | |
7bd1d409 | 579 | { |
d279a380 | 580 | unsigned int flags = ts_first ? STP_PACKET_TIMESTAMPED : 0; |
7bd1d409 | 581 | ssize_t sz; |
d279a380 | 582 | size_t pos; |
7bd1d409 | 583 | |
d279a380 | 584 | for (pos = 0, sz = 0; pos < count; pos += sz) { |
7bd1d409 | 585 | sz = min_t(unsigned int, count - pos, 8); |
d279a380 AS |
586 | sz = data->packet(data, m, c, STP_PACKET_DATA, flags, sz, |
587 | &((u8 *)buf)[pos]); | |
588 | if (sz <= 0) | |
f8560a9b | 589 | break; |
d279a380 AS |
590 | |
591 | if (ts_first) { | |
592 | flags = 0; | |
593 | ts_first = false; | |
594 | } | |
7bd1d409 AS |
595 | } |
596 | ||
d279a380 AS |
597 | return sz < 0 ? sz : pos; |
598 | } | |
599 | EXPORT_SYMBOL_GPL(stm_data_write); | |
600 | ||
24c7bcb6 AS |
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) | |
d279a380 | 604 | { |
24c7bcb6 AS |
605 | int err; |
606 | ||
607 | /* stm->pdrv is serialized against policy_mutex */ | |
608 | if (!stm->pdrv) | |
609 | return -ENODEV; | |
d279a380 | 610 | |
24c7bcb6 AS |
611 | err = stm->pdrv->write(stm->data, output, chan, buf, count); |
612 | if (err < 0) | |
613 | return err; | |
f8560a9b | 614 | |
24c7bcb6 | 615 | return err; |
7bd1d409 AS |
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 | ||
f08b1826 AS |
626 | if (count + 1 > PAGE_SIZE) |
627 | count = PAGE_SIZE - 1; | |
628 | ||
7bd1d409 | 629 | /* |
cb6102bd AS |
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. | |
7bd1d409 AS |
632 | */ |
633 | if (!stmf->output.nr_chans) { | |
cb6102bd AS |
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(stmf->stm, &stmf->output, ids, 1); | |
7bd1d409 AS |
640 | /* |
641 | * EBUSY means that somebody else just assigned this | |
642 | * output, which is just fine for write() | |
643 | */ | |
cb6102bd | 644 | if (err) |
7bd1d409 AS |
645 | return err; |
646 | } | |
647 | ||
648 | kbuf = kmalloc(count + 1, GFP_KERNEL); | |
649 | if (!kbuf) | |
650 | return -ENOMEM; | |
651 | ||
652 | err = copy_from_user(kbuf, buf, count); | |
653 | if (err) { | |
654 | kfree(kbuf); | |
655 | return -EFAULT; | |
656 | } | |
657 | ||
8e0469a4 AS |
658 | pm_runtime_get_sync(&stm->dev); |
659 | ||
24c7bcb6 | 660 | count = stm_write(stm, &stmf->output, 0, kbuf, count); |
7bd1d409 | 661 | |
8e0469a4 AS |
662 | pm_runtime_mark_last_busy(&stm->dev); |
663 | pm_runtime_put_autosuspend(&stm->dev); | |
7bd1d409 AS |
664 | kfree(kbuf); |
665 | ||
666 | return count; | |
667 | } | |
668 | ||
8e0469a4 AS |
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(&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(&stm->dev); | |
683 | pm_runtime_put_autosuspend(&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 | ||
7bd1d409 AS |
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 | ||
8e0469a4 AS |
715 | pm_runtime_get_sync(&stm->dev); |
716 | ||
7bd1d409 | 717 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
1c71222e | 718 | vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP); |
8e0469a4 | 719 | vma->vm_ops = &stm_mmap_vmops; |
7bd1d409 AS |
720 | vm_iomap_memory(vma, phys, 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; | |
cb6102bd | 729 | char *ids[] = { NULL, NULL }; |
bf7cbaae | 730 | int ret = -EINVAL, wlimit = 1; |
7bd1d409 AS |
731 | u32 size; |
732 | ||
733 | if (stmf->output.nr_chans) | |
734 | return -EBUSY; | |
735 | ||
736 | if (copy_from_user(&size, arg, sizeof(size))) | |
737 | return -EFAULT; | |
738 | ||
71c488f3 | 739 | if (size < sizeof(*id) || size >= PATH_MAX + sizeof(*id)) |
7bd1d409 AS |
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 + 1, GFP_KERNEL); | |
747 | if (!id) | |
748 | return -ENOMEM; | |
749 | ||
750 | if (copy_from_user(id, arg, size)) { | |
751 | ret = -EFAULT; | |
752 | goto err_free; | |
753 | } | |
754 | ||
755 | if (id->__reserved_0 || id->__reserved_1) | |
756 | goto err_free; | |
757 | ||
bf7cbaae AS |
758 | if (stm->data->sw_mmiosz) |
759 | wlimit = PAGE_SIZE / stm->data->sw_mmiosz; | |
760 | ||
761 | if (id->width < 1 || id->width > wlimit) | |
7bd1d409 AS |
762 | goto err_free; |
763 | ||
cb6102bd AS |
764 | ids[0] = id->id; |
765 | ret = stm_assign_first_policy(stmf->stm, &stmf->output, ids, | |
766 | id->width); | |
7bd1d409 AS |
767 | if (ret) |
768 | goto err_free; | |
769 | ||
7bd1d409 AS |
770 | if (stm->data->link) |
771 | ret = stm->data->link(stm->data, stmf->output.master, | |
772 | stmf->output.channel); | |
773 | ||
f7c81c71 | 774 | if (ret) |
7bd1d409 | 775 | stm_output_free(stmf->stm, &stmf->output); |
7bd1d409 AS |
776 | |
777 | err_free: | |
778 | kfree(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(arg, &id, 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, (void __user *)arg); | |
808 | if (err) | |
809 | return err; | |
810 | ||
811 | return stm_char_policy_get_ioctl(stmf, (void __user *)arg); | |
812 | ||
813 | case STP_POLICY_ID_GET: | |
814 | return stm_char_policy_get_ioctl(stmf, (void __user *)arg); | |
815 | ||
816 | case STP_SET_OPTIONS: | |
817 | if (copy_from_user(&options, (u64 __user *)arg, 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 | ||
7bd1d409 AS |
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, | |
407e9ef7 | 841 | .compat_ioctl = compat_ptr_ioctl, |
7bd1d409 AS |
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 | ||
b5e2ced9 | 849 | vfree(stm); |
7bd1d409 AS |
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 | ||
7b3bb0e7 | 865 | nmasters = stm_data->sw_end - stm_data->sw_start + 1; |
b5e2ced9 | 866 | stm = vzalloc(sizeof(*stm) + nmasters * sizeof(void *)); |
7bd1d409 AS |
867 | if (!stm) |
868 | return -ENOMEM; | |
869 | ||
870 | stm->major = register_chrdev(0, stm_data->name, &stm_fops); | |
871 | if (stm->major < 0) | |
872 | goto err_free; | |
873 | ||
874 | device_initialize(&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 | ||
c74f7e82 | 880 | mutex_init(&stm->link_mutex); |
7bd1d409 AS |
881 | spin_lock_init(&stm->link_lock); |
882 | INIT_LIST_HEAD(&stm->link_list); | |
883 | ||
389b6699 | 884 | /* initialize the object before it is accessible via sysfs */ |
7bd1d409 AS |
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 | ||
389b6699 AS |
892 | err = kobject_set_name(&stm->dev.kobj, "%s", stm_data->name); |
893 | if (err) | |
894 | goto err_device; | |
895 | ||
896 | err = device_add(&stm->dev); | |
897 | if (err) | |
898 | goto err_device; | |
899 | ||
8e0469a4 AS |
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(&stm->dev); | |
906 | pm_runtime_use_autosuspend(&stm->dev); | |
907 | pm_runtime_set_autosuspend_delay(&stm->dev, 2000); | |
908 | pm_runtime_set_suspended(&stm->dev); | |
909 | pm_runtime_enable(&stm->dev); | |
910 | ||
7bd1d409 AS |
911 | return 0; |
912 | ||
913 | err_device: | |
cbe4a61d AS |
914 | unregister_chrdev(stm->major, stm_data->name); |
915 | ||
f7c81c71 | 916 | /* matches device_initialize() above */ |
7bd1d409 AS |
917 | put_device(&stm->dev); |
918 | err_free: | |
b5e2ced9 | 919 | vfree(stm); |
7bd1d409 AS |
920 | |
921 | return err; | |
922 | } | |
923 | EXPORT_SYMBOL_GPL(stm_register_device); | |
924 | ||
b4ca34aa AS |
925 | static int __stm_source_link_drop(struct stm_source_device *src, |
926 | struct stm_device *stm); | |
7bd1d409 AS |
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; | |
b4ca34aa | 932 | int i, ret; |
7bd1d409 | 933 | |
8e0469a4 AS |
934 | pm_runtime_dont_use_autosuspend(&stm->dev); |
935 | pm_runtime_disable(&stm->dev); | |
936 | ||
c74f7e82 | 937 | mutex_lock(&stm->link_mutex); |
7bd1d409 | 938 | list_for_each_entry_safe(src, iter, &stm->link_list, link_entry) { |
b4ca34aa AS |
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); | |
7bd1d409 | 948 | } |
c74f7e82 | 949 | mutex_unlock(&stm->link_mutex); |
7bd1d409 AS |
950 | |
951 | synchronize_srcu(&stm_source_srcu); | |
952 | ||
953 | unregister_chrdev(stm->major, stm_data->name); | |
954 | ||
955 | mutex_lock(&stm->policy_mutex); | |
956 | if (stm->policy) | |
957 | stp_policy_unbind(stm->policy); | |
958 | mutex_unlock(&stm->policy_mutex); | |
959 | ||
73a3ed19 | 960 | for (i = stm->data->sw_start; i <= stm->data->sw_end; i++) |
7bd1d409 AS |
961 | stp_master_free(stm, i); |
962 | ||
963 | device_unregister(&stm->dev); | |
964 | stm_data->stm = NULL; | |
965 | } | |
966 | EXPORT_SYMBOL_GPL(stm_unregister_device); | |
967 | ||
c74f7e82 AS |
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 | ||
7bd1d409 AS |
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 | { | |
cb6102bd AS |
992 | char *ids[] = { NULL, "default", NULL }; |
993 | int err = -ENOMEM; | |
7bd1d409 | 994 | |
c74f7e82 | 995 | mutex_lock(&stm->link_mutex); |
7bd1d409 AS |
996 | spin_lock(&stm->link_lock); |
997 | spin_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(&src->link_entry, &stm->link_list); | |
1002 | ||
1003 | spin_unlock(&src->link_lock); | |
1004 | spin_unlock(&stm->link_lock); | |
c74f7e82 | 1005 | mutex_unlock(&stm->link_mutex); |
7bd1d409 | 1006 | |
cb6102bd AS |
1007 | ids[0] = kstrdup(src->data->name, GFP_KERNEL); |
1008 | if (!ids[0]) | |
1009 | goto fail_detach; | |
7bd1d409 | 1010 | |
cb6102bd AS |
1011 | err = stm_assign_first_policy(stm, &src->output, ids, |
1012 | src->data->nr_chans); | |
1013 | kfree(ids[0]); | |
7bd1d409 AS |
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, &src->output); | |
7bd1d409 AS |
1034 | |
1035 | fail_detach: | |
c74f7e82 | 1036 | mutex_lock(&stm->link_mutex); |
7bd1d409 AS |
1037 | spin_lock(&stm->link_lock); |
1038 | spin_lock(&src->link_lock); | |
1039 | ||
1040 | rcu_assign_pointer(src->link, NULL); | |
1041 | list_del_init(&src->link_entry); | |
1042 | ||
1043 | spin_unlock(&src->link_lock); | |
1044 | spin_unlock(&stm->link_lock); | |
c74f7e82 | 1045 | mutex_unlock(&stm->link_mutex); |
7bd1d409 AS |
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 | * | |
c74f7e82 | 1058 | * Caller must hold stm::link_mutex. |
7bd1d409 | 1059 | */ |
b4ca34aa AS |
1060 | static int __stm_source_link_drop(struct stm_source_device *src, |
1061 | struct stm_device *stm) | |
7bd1d409 | 1062 | { |
0df771de | 1063 | struct stm_device *link; |
b4ca34aa | 1064 | int ret = 0; |
0df771de | 1065 | |
c74f7e82 AS |
1066 | lockdep_assert_held(&stm->link_mutex); |
1067 | ||
c74f7e82 AS |
1068 | /* for stm::link_list modification, we hold both mutex and spinlock */ |
1069 | spin_lock(&stm->link_lock); | |
7bd1d409 | 1070 | spin_lock(&src->link_lock); |
0df771de | 1071 | link = srcu_dereference_check(src->link, &stm_source_srcu, 1); |
b4ca34aa AS |
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; | |
1810f2c4 | 1080 | goto unlock; |
b4ca34aa | 1081 | } |
7bd1d409 | 1082 | |
0df771de | 1083 | stm_output_free(link, &src->output); |
7bd1d409 | 1084 | list_del_init(&src->link_entry); |
8e0469a4 AS |
1085 | pm_runtime_mark_last_busy(&link->dev); |
1086 | pm_runtime_put_autosuspend(&link->dev); | |
7bd1d409 | 1087 | /* matches stm_find_device() from stm_source_link_store() */ |
0df771de | 1088 | stm_put_device(link); |
7bd1d409 AS |
1089 | rcu_assign_pointer(src->link, NULL); |
1090 | ||
1810f2c4 | 1091 | unlock: |
7bd1d409 | 1092 | spin_unlock(&src->link_lock); |
c74f7e82 | 1093 | spin_unlock(&stm->link_lock); |
b4ca34aa | 1094 | |
cc842407 AS |
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 | } | |
b4ca34aa AS |
1107 | |
1108 | return ret; | |
7bd1d409 AS |
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; | |
b4ca34aa | 1124 | int idx, ret; |
7bd1d409 | 1125 | |
b4ca34aa | 1126 | retry: |
7bd1d409 | 1127 | idx = srcu_read_lock(&stm_source_srcu); |
b4ca34aa AS |
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 | */ | |
7bd1d409 AS |
1133 | stm = srcu_dereference(src->link, &stm_source_srcu); |
1134 | ||
b4ca34aa | 1135 | ret = 0; |
7bd1d409 | 1136 | if (stm) { |
c74f7e82 | 1137 | mutex_lock(&stm->link_mutex); |
b4ca34aa | 1138 | ret = __stm_source_link_drop(src, stm); |
c74f7e82 | 1139 | mutex_unlock(&stm->link_mutex); |
7bd1d409 AS |
1140 | } |
1141 | ||
1142 | srcu_read_unlock(&stm_source_srcu, idx); | |
b4ca34aa AS |
1143 | |
1144 | /* if it did change, retry */ | |
1145 | if (ret == -EAGAIN) | |
1146 | goto retry; | |
7bd1d409 AS |
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(&stm_source_srcu); | |
1158 | stm = srcu_dereference(src->link, &stm_source_srcu); | |
1159 | ret = sprintf(buf, "%s\n", | |
1160 | stm ? dev_name(&stm->dev) : "<none>"); | |
1161 | srcu_read_unlock(&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 | ||
8e0469a4 AS |
1180 | pm_runtime_get(&link->dev); |
1181 | ||
7bd1d409 | 1182 | err = stm_source_link_add(src, link); |
f7c81c71 | 1183 | if (err) { |
8e0469a4 | 1184 | pm_runtime_put_autosuspend(&link->dev); |
f7c81c71 | 1185 | /* matches the stm_find_device() above */ |
7bd1d409 | 1186 | stm_put_device(link); |
f7c81c71 | 1187 | } |
7bd1d409 AS |
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(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(sizeof(*src), GFP_KERNEL); | |
1233 | if (!src) | |
1234 | return -ENOMEM; | |
1235 | ||
1236 | device_initialize(&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(&src->dev.kobj, "%s", data->name); | |
1242 | if (err) | |
1243 | goto err; | |
1244 | ||
8e0469a4 AS |
1245 | pm_runtime_no_callbacks(&src->dev); |
1246 | pm_runtime_forbid(&src->dev); | |
1247 | ||
7bd1d409 AS |
1248 | err = device_add(&src->dev); |
1249 | if (err) | |
1250 | goto err; | |
1251 | ||
cde4ad83 | 1252 | stm_output_init(&src->output); |
7bd1d409 AS |
1253 | spin_lock_init(&src->link_lock); |
1254 | INIT_LIST_HEAD(&src->link_entry); | |
1255 | src->data = data; | |
1256 | data->src = src; | |
1257 | ||
1258 | return 0; | |
1259 | ||
1260 | err: | |
1261 | put_device(&src->dev); | |
7bd1d409 AS |
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 | ||
fd085bb1 | 1279 | device_unregister(&src->dev); |
7bd1d409 AS |
1280 | } |
1281 | EXPORT_SYMBOL_GPL(stm_source_unregister_device); | |
1282 | ||
9dfed80d CZ |
1283 | int notrace stm_source_write(struct stm_source_data *data, |
1284 | unsigned int chan, | |
1285 | const char *buf, size_t count) | |
7bd1d409 AS |
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(&stm_source_srcu); | |
1298 | ||
1299 | stm = srcu_dereference(src->link, &stm_source_srcu); | |
1300 | if (stm) | |
24c7bcb6 | 1301 | count = stm_write(stm, &src->output, chan, buf, count); |
7bd1d409 AS |
1302 | else |
1303 | count = -ENODEV; | |
1304 | ||
1305 | srcu_read_unlock(&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(&stm_class); | |
1316 | if (err) | |
1317 | return err; | |
1318 | ||
1319 | err = class_register(&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); | |
c7fd62bc AS |
1328 | INIT_LIST_HEAD(&stm_pdrv_head); |
1329 | mutex_init(&stm_pdrv_mutex); | |
7bd1d409 | 1330 | |
24c7bcb6 AS |
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"); | |
7bd1d409 AS |
1337 | stm_core_up++; |
1338 | ||
1339 | return 0; | |
1340 | ||
1341 | err_src: | |
1342 | class_unregister(&stm_source_class); | |
1343 | err_stm: | |
1344 | class_unregister(&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(&stm_source_srcu); | |
1354 | class_unregister(&stm_source_class); | |
1355 | class_unregister(&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>"); |