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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
27static unsigned int stm_core_up;
28
29
30
31
32
33
34static struct srcu_struct stm_source_srcu;
35
36static 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
48static DEVICE_ATTR_RO(masters);
49
50static 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
62static DEVICE_ATTR_RO(channels);
63
64static 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
76static DEVICE_ATTR_RO(hw_override);
77
78static struct attribute *stm_attrs[] = {
79 &dev_attr_masters.attr,
80 &dev_attr_channels.attr,
81 &dev_attr_hw_override.attr,
82 NULL,
83};
84
85ATTRIBUTE_GROUPS(stm);
86
87static struct class stm_class = {
88 .name = "stm",
89 .dev_groups = stm_groups,
90};
91
92static 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
101
102
103
104
105
106
107
108
109
110
111struct 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)) {
125
126 put_device(dev);
127 return NULL;
128 }
129
130 return stm;
131}
132
133
134
135
136
137
138
139
140void stm_put_device(struct stm_device *stm)
141{
142 module_put(stm->owner);
143 put_device(&stm->dev);
144}
145
146
147
148
149
150
151
152
153
154#define __stm_master(_s, _m) \
155 ((_s)->masters[(_m) - (_s)->data->sw_start])
156
157static inline struct stp_master *
158stm_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
166static int stp_master_alloc(struct stm_device *stm, unsigned int idx)
167{
168 struct stp_master *master;
169
170 master = kzalloc(struct_size(master, chan_map,
171 BITS_TO_LONGS(stm->data->sw_nchannels)),
172 GFP_ATOMIC);
173 if (!master)
174 return -ENOMEM;
175
176 master->nr_free = stm->data->sw_nchannels;
177 __stm_master(stm, idx) = master;
178
179 return 0;
180}
181
182static void stp_master_free(struct stm_device *stm, unsigned int idx)
183{
184 struct stp_master *master = stm_master(stm, idx);
185
186 if (!master)
187 return;
188
189 __stm_master(stm, idx) = NULL;
190 kfree(master);
191}
192
193static void stm_output_claim(struct stm_device *stm, struct stm_output *output)
194{
195 struct stp_master *master = stm_master(stm, output->master);
196
197 lockdep_assert_held(&stm->mc_lock);
198 lockdep_assert_held(&output->lock);
199
200 if (WARN_ON_ONCE(master->nr_free < output->nr_chans))
201 return;
202
203 bitmap_allocate_region(&master->chan_map[0], output->channel,
204 ilog2(output->nr_chans));
205
206 master->nr_free -= output->nr_chans;
207}
208
209static void
210stm_output_disclaim(struct stm_device *stm, struct stm_output *output)
211{
212 struct stp_master *master = stm_master(stm, output->master);
213
214 lockdep_assert_held(&stm->mc_lock);
215 lockdep_assert_held(&output->lock);
216
217 bitmap_release_region(&master->chan_map[0], output->channel,
218 ilog2(output->nr_chans));
219
220 master->nr_free += output->nr_chans;
221 output->nr_chans = 0;
222}
223
224
225
226
227
228static int find_free_channels(unsigned long *bitmap, unsigned int start,
229 unsigned int end, unsigned int width)
230{
231 unsigned int pos;
232 int i;
233
234 for (pos = start; pos < end + 1; pos = ALIGN(pos, width)) {
235 pos = find_next_zero_bit(bitmap, end + 1, pos);
236 if (pos + width > end + 1)
237 break;
238
239 if (pos & (width - 1))
240 continue;
241
242 for (i = 1; i < width && !test_bit(pos + i, bitmap); i++)
243 ;
244 if (i == width)
245 return pos;
246
247
248 pos += i;
249 }
250
251 return -1;
252}
253
254static int
255stm_find_master_chan(struct stm_device *stm, unsigned int width,
256 unsigned int *mstart, unsigned int mend,
257 unsigned int *cstart, unsigned int cend)
258{
259 struct stp_master *master;
260 unsigned int midx;
261 int pos, err;
262
263 for (midx = *mstart; midx <= mend; midx++) {
264 if (!stm_master(stm, midx)) {
265 err = stp_master_alloc(stm, midx);
266 if (err)
267 return err;
268 }
269
270 master = stm_master(stm, midx);
271
272 if (!master->nr_free)
273 continue;
274
275 pos = find_free_channels(master->chan_map, *cstart, cend,
276 width);
277 if (pos < 0)
278 continue;
279
280 *mstart = midx;
281 *cstart = pos;
282 return 0;
283 }
284
285 return -ENOSPC;
286}
287
288static int stm_output_assign(struct stm_device *stm, unsigned int width,
289 struct stp_policy_node *policy_node,
290 struct stm_output *output)
291{
292 unsigned int midx, cidx, mend, cend;
293 int ret = -EINVAL;
294
295 if (width > stm->data->sw_nchannels)
296 return -EINVAL;
297
298
299 if (WARN_ON_ONCE(!policy_node))
300 return -EINVAL;
301
302
303
304
305
306 stp_policy_node_get_ranges(policy_node, &midx, &mend, &cidx, &cend);
307
308 spin_lock(&stm->mc_lock);
309 spin_lock(&output->lock);
310
311 if (WARN_ON_ONCE(output->nr_chans))
312 goto unlock;
313
314 ret = stm_find_master_chan(stm, width, &midx, mend, &cidx, cend);
315 if (ret < 0)
316 goto unlock;
317
318 output->master = midx;
319 output->channel = cidx;
320 output->nr_chans = width;
321 if (stm->pdrv->output_open) {
322 void *priv = stp_policy_node_priv(policy_node);
323
324 if (WARN_ON_ONCE(!priv))
325 goto unlock;
326
327
328 ret = stm->pdrv->output_open(priv, output);
329 if (ret)
330 goto unlock;
331 }
332
333 stm_output_claim(stm, output);
334 dev_dbg(&stm->dev, "assigned %u:%u (+%u)\n", midx, cidx, width);
335
336 ret = 0;
337unlock:
338 if (ret)
339 output->nr_chans = 0;
340
341 spin_unlock(&output->lock);
342 spin_unlock(&stm->mc_lock);
343
344 return ret;
345}
346
347static void stm_output_free(struct stm_device *stm, struct stm_output *output)
348{
349 spin_lock(&stm->mc_lock);
350 spin_lock(&output->lock);
351 if (output->nr_chans)
352 stm_output_disclaim(stm, output);
353 if (stm->pdrv && stm->pdrv->output_close)
354 stm->pdrv->output_close(output);
355 spin_unlock(&output->lock);
356 spin_unlock(&stm->mc_lock);
357}
358
359static void stm_output_init(struct stm_output *output)
360{
361 spin_lock_init(&output->lock);
362}
363
364static int major_match(struct device *dev, const void *data)
365{
366 unsigned int major = *(unsigned int *)data;
367
368 return MAJOR(dev->devt) == major;
369}
370
371
372
373
374
375
376static struct list_head stm_pdrv_head;
377static struct mutex stm_pdrv_mutex;
378
379struct stm_pdrv_entry {
380 struct list_head entry;
381 const struct stm_protocol_driver *pdrv;
382 const struct config_item_type *node_type;
383};
384
385static const struct stm_pdrv_entry *
386__stm_lookup_protocol(const char *name)
387{
388 struct stm_pdrv_entry *pe;
389
390
391
392
393 if (!name || !*name)
394 name = "p_basic";
395
396 list_for_each_entry(pe, &stm_pdrv_head, entry) {
397 if (!strcmp(name, pe->pdrv->name))
398 return pe;
399 }
400
401 return NULL;
402}
403
404int stm_register_protocol(const struct stm_protocol_driver *pdrv)
405{
406 struct stm_pdrv_entry *pe = NULL;
407 int ret = -ENOMEM;
408
409 mutex_lock(&stm_pdrv_mutex);
410
411 if (__stm_lookup_protocol(pdrv->name)) {
412 ret = -EEXIST;
413 goto unlock;
414 }
415
416 pe = kzalloc(sizeof(*pe), GFP_KERNEL);
417 if (!pe)
418 goto unlock;
419
420 if (pdrv->policy_attr) {
421 pe->node_type = get_policy_node_type(pdrv->policy_attr);
422 if (!pe->node_type)
423 goto unlock;
424 }
425
426 list_add_tail(&pe->entry, &stm_pdrv_head);
427 pe->pdrv = pdrv;
428
429 ret = 0;
430unlock:
431 mutex_unlock(&stm_pdrv_mutex);
432
433 if (ret)
434 kfree(pe);
435
436 return ret;
437}
438EXPORT_SYMBOL_GPL(stm_register_protocol);
439
440void stm_unregister_protocol(const struct stm_protocol_driver *pdrv)
441{
442 struct stm_pdrv_entry *pe, *iter;
443
444 mutex_lock(&stm_pdrv_mutex);
445
446 list_for_each_entry_safe(pe, iter, &stm_pdrv_head, entry) {
447 if (pe->pdrv == pdrv) {
448 list_del(&pe->entry);
449
450 if (pe->node_type) {
451 kfree(pe->node_type->ct_attrs);
452 kfree(pe->node_type);
453 }
454 kfree(pe);
455 break;
456 }
457 }
458
459 mutex_unlock(&stm_pdrv_mutex);
460}
461EXPORT_SYMBOL_GPL(stm_unregister_protocol);
462
463static bool stm_get_protocol(const struct stm_protocol_driver *pdrv)
464{
465 return try_module_get(pdrv->owner);
466}
467
468void stm_put_protocol(const struct stm_protocol_driver *pdrv)
469{
470 module_put(pdrv->owner);
471}
472
473int stm_lookup_protocol(const char *name,
474 const struct stm_protocol_driver **pdrv,
475 const struct config_item_type **node_type)
476{
477 const struct stm_pdrv_entry *pe;
478
479 mutex_lock(&stm_pdrv_mutex);
480
481 pe = __stm_lookup_protocol(name);
482 if (pe && pe->pdrv && stm_get_protocol(pe->pdrv)) {
483 *pdrv = pe->pdrv;
484 *node_type = pe->node_type;
485 }
486
487 mutex_unlock(&stm_pdrv_mutex);
488
489 return pe ? 0 : -ENOENT;
490}
491
492static int stm_char_open(struct inode *inode, struct file *file)
493{
494 struct stm_file *stmf;
495 struct device *dev;
496 unsigned int major = imajor(inode);
497 int err = -ENOMEM;
498
499 dev = class_find_device(&stm_class, NULL, &major, major_match);
500 if (!dev)
501 return -ENODEV;
502
503 stmf = kzalloc(sizeof(*stmf), GFP_KERNEL);
504 if (!stmf)
505 goto err_put_device;
506
507 err = -ENODEV;
508 stm_output_init(&stmf->output);
509 stmf->stm = to_stm_device(dev);
510
511 if (!try_module_get(stmf->stm->owner))
512 goto err_free;
513
514 file->private_data = stmf;
515
516 return nonseekable_open(inode, file);
517
518err_free:
519 kfree(stmf);
520err_put_device:
521
522 put_device(dev);
523
524 return err;
525}
526
527static int stm_char_release(struct inode *inode, struct file *file)
528{
529 struct stm_file *stmf = file->private_data;
530 struct stm_device *stm = stmf->stm;
531
532 if (stm->data->unlink)
533 stm->data->unlink(stm->data, stmf->output.master,
534 stmf->output.channel);
535
536 stm_output_free(stm, &stmf->output);
537
538
539
540
541
542 stm_put_device(stm);
543 kfree(stmf);
544
545 return 0;
546}
547
548static int
549stm_assign_first_policy(struct stm_device *stm, struct stm_output *output,
550 char **ids, unsigned int width)
551{
552 struct stp_policy_node *pn;
553 int err, n;
554
555
556
557
558
559
560
561 for (n = 0, pn = NULL; ids[n] && !pn; n++)
562 pn = stp_policy_node_lookup(stm, ids[n]);
563
564 if (!pn)
565 return -EINVAL;
566
567 err = stm_output_assign(stm, width, pn, output);
568
569 stp_policy_node_put(pn);
570
571 return err;
572}
573
574
575
576
577
578
579
580
581
582
583ssize_t notrace stm_data_write(struct stm_data *data, unsigned int m,
584 unsigned int c, bool ts_first, const void *buf,
585 size_t count)
586{
587 unsigned int flags = ts_first ? STP_PACKET_TIMESTAMPED : 0;
588 ssize_t sz;
589 size_t pos;
590
591 for (pos = 0, sz = 0; pos < count; pos += sz) {
592 sz = min_t(unsigned int, count - pos, 8);
593 sz = data->packet(data, m, c, STP_PACKET_DATA, flags, sz,
594 &((u8 *)buf)[pos]);
595 if (sz <= 0)
596 break;
597
598 if (ts_first) {
599 flags = 0;
600 ts_first = false;
601 }
602 }
603
604 return sz < 0 ? sz : pos;
605}
606EXPORT_SYMBOL_GPL(stm_data_write);
607
608static ssize_t notrace
609stm_write(struct stm_device *stm, struct stm_output *output,
610 unsigned int chan, const char *buf, size_t count)
611{
612 int err;
613
614
615 if (!stm->pdrv)
616 return -ENODEV;
617
618 err = stm->pdrv->write(stm->data, output, chan, buf, count);
619 if (err < 0)
620 return err;
621
622 return err;
623}
624
625static ssize_t stm_char_write(struct file *file, const char __user *buf,
626 size_t count, loff_t *ppos)
627{
628 struct stm_file *stmf = file->private_data;
629 struct stm_device *stm = stmf->stm;
630 char *kbuf;
631 int err;
632
633 if (count + 1 > PAGE_SIZE)
634 count = PAGE_SIZE - 1;
635
636
637
638
639
640 if (!stmf->output.nr_chans) {
641 char comm[sizeof(current->comm)];
642 char *ids[] = { comm, "default", NULL };
643
644 get_task_comm(comm, current);
645
646 err = stm_assign_first_policy(stmf->stm, &stmf->output, ids, 1);
647
648
649
650
651 if (err)
652 return err;
653 }
654
655 kbuf = kmalloc(count + 1, GFP_KERNEL);
656 if (!kbuf)
657 return -ENOMEM;
658
659 err = copy_from_user(kbuf, buf, count);
660 if (err) {
661 kfree(kbuf);
662 return -EFAULT;
663 }
664
665 pm_runtime_get_sync(&stm->dev);
666
667 count = stm_write(stm, &stmf->output, 0, kbuf, count);
668
669 pm_runtime_mark_last_busy(&stm->dev);
670 pm_runtime_put_autosuspend(&stm->dev);
671 kfree(kbuf);
672
673 return count;
674}
675
676static void stm_mmap_open(struct vm_area_struct *vma)
677{
678 struct stm_file *stmf = vma->vm_file->private_data;
679 struct stm_device *stm = stmf->stm;
680
681 pm_runtime_get(&stm->dev);
682}
683
684static void stm_mmap_close(struct vm_area_struct *vma)
685{
686 struct stm_file *stmf = vma->vm_file->private_data;
687 struct stm_device *stm = stmf->stm;
688
689 pm_runtime_mark_last_busy(&stm->dev);
690 pm_runtime_put_autosuspend(&stm->dev);
691}
692
693static const struct vm_operations_struct stm_mmap_vmops = {
694 .open = stm_mmap_open,
695 .close = stm_mmap_close,
696};
697
698static int stm_char_mmap(struct file *file, struct vm_area_struct *vma)
699{
700 struct stm_file *stmf = file->private_data;
701 struct stm_device *stm = stmf->stm;
702 unsigned long size, phys;
703
704 if (!stm->data->mmio_addr)
705 return -EOPNOTSUPP;
706
707 if (vma->vm_pgoff)
708 return -EINVAL;
709
710 size = vma->vm_end - vma->vm_start;
711
712 if (stmf->output.nr_chans * stm->data->sw_mmiosz != size)
713 return -EINVAL;
714
715 phys = stm->data->mmio_addr(stm->data, stmf->output.master,
716 stmf->output.channel,
717 stmf->output.nr_chans);
718
719 if (!phys)
720 return -EINVAL;
721
722 pm_runtime_get_sync(&stm->dev);
723
724 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
725 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
726 vma->vm_ops = &stm_mmap_vmops;
727 vm_iomap_memory(vma, phys, size);
728
729 return 0;
730}
731
732static int stm_char_policy_set_ioctl(struct stm_file *stmf, void __user *arg)
733{
734 struct stm_device *stm = stmf->stm;
735 struct stp_policy_id *id;
736 char *ids[] = { NULL, NULL };
737 int ret = -EINVAL, wlimit = 1;
738 u32 size;
739
740 if (stmf->output.nr_chans)
741 return -EBUSY;
742
743 if (copy_from_user(&size, arg, sizeof(size)))
744 return -EFAULT;
745
746 if (size < sizeof(*id) || size >= PATH_MAX + sizeof(*id))
747 return -EINVAL;
748
749
750
751
752
753 id = kzalloc(size + 1, GFP_KERNEL);
754 if (!id)
755 return -ENOMEM;
756
757 if (copy_from_user(id, arg, size)) {
758 ret = -EFAULT;
759 goto err_free;
760 }
761
762 if (id->__reserved_0 || id->__reserved_1)
763 goto err_free;
764
765 if (stm->data->sw_mmiosz)
766 wlimit = PAGE_SIZE / stm->data->sw_mmiosz;
767
768 if (id->width < 1 || id->width > wlimit)
769 goto err_free;
770
771 ids[0] = id->id;
772 ret = stm_assign_first_policy(stmf->stm, &stmf->output, ids,
773 id->width);
774 if (ret)
775 goto err_free;
776
777 if (stm->data->link)
778 ret = stm->data->link(stm->data, stmf->output.master,
779 stmf->output.channel);
780
781 if (ret)
782 stm_output_free(stmf->stm, &stmf->output);
783
784err_free:
785 kfree(id);
786
787 return ret;
788}
789
790static int stm_char_policy_get_ioctl(struct stm_file *stmf, void __user *arg)
791{
792 struct stp_policy_id id = {
793 .size = sizeof(id),
794 .master = stmf->output.master,
795 .channel = stmf->output.channel,
796 .width = stmf->output.nr_chans,
797 .__reserved_0 = 0,
798 .__reserved_1 = 0,
799 };
800
801 return copy_to_user(arg, &id, id.size) ? -EFAULT : 0;
802}
803
804static long
805stm_char_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
806{
807 struct stm_file *stmf = file->private_data;
808 struct stm_data *stm_data = stmf->stm->data;
809 int err = -ENOTTY;
810 u64 options;
811
812 switch (cmd) {
813 case STP_POLICY_ID_SET:
814 err = stm_char_policy_set_ioctl(stmf, (void __user *)arg);
815 if (err)
816 return err;
817
818 return stm_char_policy_get_ioctl(stmf, (void __user *)arg);
819
820 case STP_POLICY_ID_GET:
821 return stm_char_policy_get_ioctl(stmf, (void __user *)arg);
822
823 case STP_SET_OPTIONS:
824 if (copy_from_user(&options, (u64 __user *)arg, sizeof(u64)))
825 return -EFAULT;
826
827 if (stm_data->set_options)
828 err = stm_data->set_options(stm_data,
829 stmf->output.master,
830 stmf->output.channel,
831 stmf->output.nr_chans,
832 options);
833
834 break;
835 default:
836 break;
837 }
838
839 return err;
840}
841
842#ifdef CONFIG_COMPAT
843static long
844stm_char_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
845{
846 return stm_char_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
847}
848#else
849#define stm_char_compat_ioctl NULL
850#endif
851
852static const struct file_operations stm_fops = {
853 .open = stm_char_open,
854 .release = stm_char_release,
855 .write = stm_char_write,
856 .mmap = stm_char_mmap,
857 .unlocked_ioctl = stm_char_ioctl,
858 .compat_ioctl = stm_char_compat_ioctl,
859 .llseek = no_llseek,
860};
861
862static void stm_device_release(struct device *dev)
863{
864 struct stm_device *stm = to_stm_device(dev);
865
866 vfree(stm);
867}
868
869int stm_register_device(struct device *parent, struct stm_data *stm_data,
870 struct module *owner)
871{
872 struct stm_device *stm;
873 unsigned int nmasters;
874 int err = -ENOMEM;
875
876 if (!stm_core_up)
877 return -EPROBE_DEFER;
878
879 if (!stm_data->packet || !stm_data->sw_nchannels)
880 return -EINVAL;
881
882 nmasters = stm_data->sw_end - stm_data->sw_start + 1;
883 stm = vzalloc(sizeof(*stm) + nmasters * sizeof(void *));
884 if (!stm)
885 return -ENOMEM;
886
887 stm->major = register_chrdev(0, stm_data->name, &stm_fops);
888 if (stm->major < 0)
889 goto err_free;
890
891 device_initialize(&stm->dev);
892 stm->dev.devt = MKDEV(stm->major, 0);
893 stm->dev.class = &stm_class;
894 stm->dev.parent = parent;
895 stm->dev.release = stm_device_release;
896
897 mutex_init(&stm->link_mutex);
898 spin_lock_init(&stm->link_lock);
899 INIT_LIST_HEAD(&stm->link_list);
900
901
902 spin_lock_init(&stm->mc_lock);
903 mutex_init(&stm->policy_mutex);
904 stm->sw_nmasters = nmasters;
905 stm->owner = owner;
906 stm->data = stm_data;
907 stm_data->stm = stm;
908
909 err = kobject_set_name(&stm->dev.kobj, "%s", stm_data->name);
910 if (err)
911 goto err_device;
912
913 err = device_add(&stm->dev);
914 if (err)
915 goto err_device;
916
917
918
919
920
921
922 pm_runtime_no_callbacks(&stm->dev);
923 pm_runtime_use_autosuspend(&stm->dev);
924 pm_runtime_set_autosuspend_delay(&stm->dev, 2000);
925 pm_runtime_set_suspended(&stm->dev);
926 pm_runtime_enable(&stm->dev);
927
928 return 0;
929
930err_device:
931 unregister_chrdev(stm->major, stm_data->name);
932
933
934 put_device(&stm->dev);
935err_free:
936 vfree(stm);
937
938 return err;
939}
940EXPORT_SYMBOL_GPL(stm_register_device);
941
942static int __stm_source_link_drop(struct stm_source_device *src,
943 struct stm_device *stm);
944
945void stm_unregister_device(struct stm_data *stm_data)
946{
947 struct stm_device *stm = stm_data->stm;
948 struct stm_source_device *src, *iter;
949 int i, ret;
950
951 pm_runtime_dont_use_autosuspend(&stm->dev);
952 pm_runtime_disable(&stm->dev);
953
954 mutex_lock(&stm->link_mutex);
955 list_for_each_entry_safe(src, iter, &stm->link_list, link_entry) {
956 ret = __stm_source_link_drop(src, stm);
957
958
959
960
961
962
963
964 WARN_ON_ONCE(ret);
965 }
966 mutex_unlock(&stm->link_mutex);
967
968 synchronize_srcu(&stm_source_srcu);
969
970 unregister_chrdev(stm->major, stm_data->name);
971
972 mutex_lock(&stm->policy_mutex);
973 if (stm->policy)
974 stp_policy_unbind(stm->policy);
975 mutex_unlock(&stm->policy_mutex);
976
977 for (i = stm->data->sw_start; i <= stm->data->sw_end; i++)
978 stp_master_free(stm, i);
979
980 device_unregister(&stm->dev);
981 stm_data->stm = NULL;
982}
983EXPORT_SYMBOL_GPL(stm_unregister_device);
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006static int stm_source_link_add(struct stm_source_device *src,
1007 struct stm_device *stm)
1008{
1009 char *ids[] = { NULL, "default", NULL };
1010 int err = -ENOMEM;
1011
1012 mutex_lock(&stm->link_mutex);
1013 spin_lock(&stm->link_lock);
1014 spin_lock(&src->link_lock);
1015
1016
1017 rcu_assign_pointer(src->link, stm);
1018 list_add_tail(&src->link_entry, &stm->link_list);
1019
1020 spin_unlock(&src->link_lock);
1021 spin_unlock(&stm->link_lock);
1022 mutex_unlock(&stm->link_mutex);
1023
1024 ids[0] = kstrdup(src->data->name, GFP_KERNEL);
1025 if (!ids[0])
1026 goto fail_detach;
1027
1028 err = stm_assign_first_policy(stm, &src->output, ids,
1029 src->data->nr_chans);
1030 kfree(ids[0]);
1031
1032 if (err)
1033 goto fail_detach;
1034
1035
1036 if (stm->data->link)
1037 err = stm->data->link(stm->data, src->output.master,
1038 src->output.channel);
1039
1040 if (err)
1041 goto fail_free_output;
1042
1043
1044 if (src->data->link)
1045 src->data->link(src->data);
1046
1047 return 0;
1048
1049fail_free_output:
1050 stm_output_free(stm, &src->output);
1051
1052fail_detach:
1053 mutex_lock(&stm->link_mutex);
1054 spin_lock(&stm->link_lock);
1055 spin_lock(&src->link_lock);
1056
1057 rcu_assign_pointer(src->link, NULL);
1058 list_del_init(&src->link_entry);
1059
1060 spin_unlock(&src->link_lock);
1061 spin_unlock(&stm->link_lock);
1062 mutex_unlock(&stm->link_mutex);
1063
1064 return err;
1065}
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077static int __stm_source_link_drop(struct stm_source_device *src,
1078 struct stm_device *stm)
1079{
1080 struct stm_device *link;
1081 int ret = 0;
1082
1083 lockdep_assert_held(&stm->link_mutex);
1084
1085
1086 spin_lock(&stm->link_lock);
1087 spin_lock(&src->link_lock);
1088 link = srcu_dereference_check(src->link, &stm_source_srcu, 1);
1089
1090
1091
1092
1093
1094
1095 if (link != stm) {
1096 ret = -EAGAIN;
1097 goto unlock;
1098 }
1099
1100 stm_output_free(link, &src->output);
1101 list_del_init(&src->link_entry);
1102 pm_runtime_mark_last_busy(&link->dev);
1103 pm_runtime_put_autosuspend(&link->dev);
1104
1105 stm_put_device(link);
1106 rcu_assign_pointer(src->link, NULL);
1107
1108unlock:
1109 spin_unlock(&src->link_lock);
1110 spin_unlock(&stm->link_lock);
1111
1112
1113
1114
1115
1116 if (!ret) {
1117 if (src->data->unlink)
1118 src->data->unlink(src->data);
1119
1120 if (stm->data->unlink)
1121 stm->data->unlink(stm->data, src->output.master,
1122 src->output.channel);
1123 }
1124
1125 return ret;
1126}
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138static void stm_source_link_drop(struct stm_source_device *src)
1139{
1140 struct stm_device *stm;
1141 int idx, ret;
1142
1143retry:
1144 idx = srcu_read_lock(&stm_source_srcu);
1145
1146
1147
1148
1149
1150 stm = srcu_dereference(src->link, &stm_source_srcu);
1151
1152 ret = 0;
1153 if (stm) {
1154 mutex_lock(&stm->link_mutex);
1155 ret = __stm_source_link_drop(src, stm);
1156 mutex_unlock(&stm->link_mutex);
1157 }
1158
1159 srcu_read_unlock(&stm_source_srcu, idx);
1160
1161
1162 if (ret == -EAGAIN)
1163 goto retry;
1164}
1165
1166static ssize_t stm_source_link_show(struct device *dev,
1167 struct device_attribute *attr,
1168 char *buf)
1169{
1170 struct stm_source_device *src = to_stm_source_device(dev);
1171 struct stm_device *stm;
1172 int idx, ret;
1173
1174 idx = srcu_read_lock(&stm_source_srcu);
1175 stm = srcu_dereference(src->link, &stm_source_srcu);
1176 ret = sprintf(buf, "%s\n",
1177 stm ? dev_name(&stm->dev) : "<none>");
1178 srcu_read_unlock(&stm_source_srcu, idx);
1179
1180 return ret;
1181}
1182
1183static ssize_t stm_source_link_store(struct device *dev,
1184 struct device_attribute *attr,
1185 const char *buf, size_t count)
1186{
1187 struct stm_source_device *src = to_stm_source_device(dev);
1188 struct stm_device *link;
1189 int err;
1190
1191 stm_source_link_drop(src);
1192
1193 link = stm_find_device(buf);
1194 if (!link)
1195 return -EINVAL;
1196
1197 pm_runtime_get(&link->dev);
1198
1199 err = stm_source_link_add(src, link);
1200 if (err) {
1201 pm_runtime_put_autosuspend(&link->dev);
1202
1203 stm_put_device(link);
1204 }
1205
1206 return err ? : count;
1207}
1208
1209static DEVICE_ATTR_RW(stm_source_link);
1210
1211static struct attribute *stm_source_attrs[] = {
1212 &dev_attr_stm_source_link.attr,
1213 NULL,
1214};
1215
1216ATTRIBUTE_GROUPS(stm_source);
1217
1218static struct class stm_source_class = {
1219 .name = "stm_source",
1220 .dev_groups = stm_source_groups,
1221};
1222
1223static void stm_source_device_release(struct device *dev)
1224{
1225 struct stm_source_device *src = to_stm_source_device(dev);
1226
1227 kfree(src);
1228}
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240int stm_source_register_device(struct device *parent,
1241 struct stm_source_data *data)
1242{
1243 struct stm_source_device *src;
1244 int err;
1245
1246 if (!stm_core_up)
1247 return -EPROBE_DEFER;
1248
1249 src = kzalloc(sizeof(*src), GFP_KERNEL);
1250 if (!src)
1251 return -ENOMEM;
1252
1253 device_initialize(&src->dev);
1254 src->dev.class = &stm_source_class;
1255 src->dev.parent = parent;
1256 src->dev.release = stm_source_device_release;
1257
1258 err = kobject_set_name(&src->dev.kobj, "%s", data->name);
1259 if (err)
1260 goto err;
1261
1262 pm_runtime_no_callbacks(&src->dev);
1263 pm_runtime_forbid(&src->dev);
1264
1265 err = device_add(&src->dev);
1266 if (err)
1267 goto err;
1268
1269 stm_output_init(&src->output);
1270 spin_lock_init(&src->link_lock);
1271 INIT_LIST_HEAD(&src->link_entry);
1272 src->data = data;
1273 data->src = src;
1274
1275 return 0;
1276
1277err:
1278 put_device(&src->dev);
1279
1280 return err;
1281}
1282EXPORT_SYMBOL_GPL(stm_source_register_device);
1283
1284
1285
1286
1287
1288
1289
1290void stm_source_unregister_device(struct stm_source_data *data)
1291{
1292 struct stm_source_device *src = data->src;
1293
1294 stm_source_link_drop(src);
1295
1296 device_unregister(&src->dev);
1297}
1298EXPORT_SYMBOL_GPL(stm_source_unregister_device);
1299
1300int notrace stm_source_write(struct stm_source_data *data,
1301 unsigned int chan,
1302 const char *buf, size_t count)
1303{
1304 struct stm_source_device *src = data->src;
1305 struct stm_device *stm;
1306 int idx;
1307
1308 if (!src->output.nr_chans)
1309 return -ENODEV;
1310
1311 if (chan >= src->output.nr_chans)
1312 return -EINVAL;
1313
1314 idx = srcu_read_lock(&stm_source_srcu);
1315
1316 stm = srcu_dereference(src->link, &stm_source_srcu);
1317 if (stm)
1318 count = stm_write(stm, &src->output, chan, buf, count);
1319 else
1320 count = -ENODEV;
1321
1322 srcu_read_unlock(&stm_source_srcu, idx);
1323
1324 return count;
1325}
1326EXPORT_SYMBOL_GPL(stm_source_write);
1327
1328static int __init stm_core_init(void)
1329{
1330 int err;
1331
1332 err = class_register(&stm_class);
1333 if (err)
1334 return err;
1335
1336 err = class_register(&stm_source_class);
1337 if (err)
1338 goto err_stm;
1339
1340 err = stp_configfs_init();
1341 if (err)
1342 goto err_src;
1343
1344 init_srcu_struct(&stm_source_srcu);
1345 INIT_LIST_HEAD(&stm_pdrv_head);
1346 mutex_init(&stm_pdrv_mutex);
1347
1348
1349
1350
1351
1352 if (IS_ENABLED(CONFIG_STM_PROTO_BASIC))
1353 (void)request_module_nowait("stm_p_basic");
1354 stm_core_up++;
1355
1356 return 0;
1357
1358err_src:
1359 class_unregister(&stm_source_class);
1360err_stm:
1361 class_unregister(&stm_class);
1362
1363 return err;
1364}
1365
1366module_init(stm_core_init);
1367
1368static void __exit stm_core_exit(void)
1369{
1370 cleanup_srcu_struct(&stm_source_srcu);
1371 class_unregister(&stm_source_class);
1372 class_unregister(&stm_class);
1373 stp_configfs_exit();
1374}
1375
1376module_exit(stm_core_exit);
1377
1378MODULE_LICENSE("GPL v2");
1379MODULE_DESCRIPTION("System Trace Module device class");
1380MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");
1381