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staging: speakup: Remove the explicit NULL comparison
[linux-2.6-block.git] / drivers / staging / greybus / loopback.c
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CommitLineData
1/*
2 * Loopback bridge driver for the Greybus loopback module.
3 *
4 * Copyright 2014 Google Inc.
5 * Copyright 2014 Linaro Ltd.
6 *
7 * Released under the GPLv2 only.
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/mutex.h>
15#include <linux/slab.h>
16#include <linux/kthread.h>
17#include <linux/delay.h>
18#include <linux/random.h>
19#include <linux/sizes.h>
20#include <linux/cdev.h>
21#include <linux/fs.h>
22#include <linux/kfifo.h>
23#include <linux/debugfs.h>
24#include <linux/list_sort.h>
25#include <linux/spinlock.h>
26#include <linux/workqueue.h>
27#include <linux/atomic.h>
28#include <linux/pm_runtime.h>
29
30#include <asm/div64.h>
31
32#include "greybus.h"
33#include "connection.h"
34
35#define NSEC_PER_DAY 86400000000000ULL
36
37struct gb_loopback_stats {
38 u32 min;
39 u32 max;
40 u64 sum;
41 u32 count;
42};
43
44struct gb_loopback_device {
45 struct dentry *root;
46 u32 count;
47 size_t size_max;
48
49 /* We need to take a lock in atomic context */
50 spinlock_t lock;
51 struct list_head list;
52 struct list_head list_op_async;
53 wait_queue_head_t wq;
54};
55
56static struct gb_loopback_device gb_dev;
57
58struct gb_loopback_async_operation {
59 struct gb_loopback *gb;
60 struct gb_operation *operation;
61 struct timeval ts;
62 struct timer_list timer;
63 struct list_head entry;
64 struct work_struct work;
65 struct kref kref;
66 bool pending;
67 int (*completion)(struct gb_loopback_async_operation *op_async);
68};
69
70struct gb_loopback {
71 struct gb_connection *connection;
72
73 struct dentry *file;
74 struct kfifo kfifo_lat;
75 struct kfifo kfifo_ts;
76 struct mutex mutex;
77 struct task_struct *task;
78 struct list_head entry;
79 struct device *dev;
80 wait_queue_head_t wq;
81 wait_queue_head_t wq_completion;
82 atomic_t outstanding_operations;
83
84 /* Per connection stats */
85 struct timeval ts;
86 struct gb_loopback_stats latency;
87 struct gb_loopback_stats throughput;
88 struct gb_loopback_stats requests_per_second;
89 struct gb_loopback_stats apbridge_unipro_latency;
90 struct gb_loopback_stats gbphy_firmware_latency;
91
92 int type;
93 int async;
94 int id;
95 u32 size;
96 u32 iteration_max;
97 u32 iteration_count;
98 int us_wait;
99 u32 error;
100 u32 requests_completed;
101 u32 requests_timedout;
102 u32 timeout;
103 u32 jiffy_timeout;
104 u32 timeout_min;
105 u32 timeout_max;
106 u32 outstanding_operations_max;
107 u32 lbid;
108 u64 elapsed_nsecs;
109 u32 apbridge_latency_ts;
110 u32 gbphy_latency_ts;
111
112 u32 send_count;
113};
114
115static struct class loopback_class = {
116 .name = "gb_loopback",
117 .owner = THIS_MODULE,
118};
119static DEFINE_IDA(loopback_ida);
120
121/* Min/max values in jiffies */
122#define GB_LOOPBACK_TIMEOUT_MIN 1
123#define GB_LOOPBACK_TIMEOUT_MAX 10000
124
125#define GB_LOOPBACK_FIFO_DEFAULT 8192
126
127static unsigned int kfifo_depth = GB_LOOPBACK_FIFO_DEFAULT;
128module_param(kfifo_depth, uint, 0444);
129
130/* Maximum size of any one send data buffer we support */
131#define MAX_PACKET_SIZE (PAGE_SIZE * 2)
132
133#define GB_LOOPBACK_US_WAIT_MAX 1000000
134
135/* interface sysfs attributes */
136#define gb_loopback_ro_attr(field) \
137static ssize_t field##_show(struct device *dev, \
138 struct device_attribute *attr, \
139 char *buf) \
140{ \
141 struct gb_loopback *gb = dev_get_drvdata(dev); \
142 return sprintf(buf, "%u\n", gb->field); \
143} \
144static DEVICE_ATTR_RO(field)
145
146#define gb_loopback_ro_stats_attr(name, field, type) \
147static ssize_t name##_##field##_show(struct device *dev, \
148 struct device_attribute *attr, \
149 char *buf) \
150{ \
151 struct gb_loopback *gb = dev_get_drvdata(dev); \
152 /* Report 0 for min and max if no transfer successed */ \
153 if (!gb->requests_completed) \
154 return sprintf(buf, "0\n"); \
155 return sprintf(buf, "%"#type"\n", gb->name.field); \
156} \
157static DEVICE_ATTR_RO(name##_##field)
158
159#define gb_loopback_ro_avg_attr(name) \
160static ssize_t name##_avg_show(struct device *dev, \
161 struct device_attribute *attr, \
162 char *buf) \
163{ \
164 struct gb_loopback_stats *stats; \
165 struct gb_loopback *gb; \
166 u64 avg, rem; \
167 u32 count; \
168 gb = dev_get_drvdata(dev); \
169 stats = &gb->name; \
170 count = stats->count ? stats->count : 1; \
171 avg = stats->sum + count / 2000000; /* round closest */ \
172 rem = do_div(avg, count); \
173 rem *= 1000000; \
174 do_div(rem, count); \
175 return sprintf(buf, "%llu.%06u\n", avg, (u32)rem); \
176} \
177static DEVICE_ATTR_RO(name##_avg)
178
179#define gb_loopback_stats_attrs(field) \
180 gb_loopback_ro_stats_attr(field, min, u); \
181 gb_loopback_ro_stats_attr(field, max, u); \
182 gb_loopback_ro_avg_attr(field)
183
184#define gb_loopback_attr(field, type) \
185static ssize_t field##_show(struct device *dev, \
186 struct device_attribute *attr, \
187 char *buf) \
188{ \
189 struct gb_loopback *gb = dev_get_drvdata(dev); \
190 return sprintf(buf, "%"#type"\n", gb->field); \
191} \
192static ssize_t field##_store(struct device *dev, \
193 struct device_attribute *attr, \
194 const char *buf, \
195 size_t len) \
196{ \
197 int ret; \
198 struct gb_loopback *gb = dev_get_drvdata(dev); \
199 mutex_lock(&gb->mutex); \
200 ret = sscanf(buf, "%"#type, &gb->field); \
201 if (ret != 1) \
202 len = -EINVAL; \
203 else \
204 gb_loopback_check_attr(gb, bundle); \
205 mutex_unlock(&gb->mutex); \
206 return len; \
207} \
208static DEVICE_ATTR_RW(field)
209
210#define gb_dev_loopback_ro_attr(field, conn) \
211static ssize_t field##_show(struct device *dev, \
212 struct device_attribute *attr, \
213 char *buf) \
214{ \
215 struct gb_loopback *gb = dev_get_drvdata(dev); \
216 return sprintf(buf, "%u\n", gb->field); \
217} \
218static DEVICE_ATTR_RO(field)
219
220#define gb_dev_loopback_rw_attr(field, type) \
221static ssize_t field##_show(struct device *dev, \
222 struct device_attribute *attr, \
223 char *buf) \
224{ \
225 struct gb_loopback *gb = dev_get_drvdata(dev); \
226 return sprintf(buf, "%"#type"\n", gb->field); \
227} \
228static ssize_t field##_store(struct device *dev, \
229 struct device_attribute *attr, \
230 const char *buf, \
231 size_t len) \
232{ \
233 int ret; \
234 struct gb_loopback *gb = dev_get_drvdata(dev); \
235 mutex_lock(&gb->mutex); \
236 ret = sscanf(buf, "%"#type, &gb->field); \
237 if (ret != 1) \
238 len = -EINVAL; \
239 else \
240 gb_loopback_check_attr(gb); \
241 mutex_unlock(&gb->mutex); \
242 return len; \
243} \
244static DEVICE_ATTR_RW(field)
245
246static void gb_loopback_reset_stats(struct gb_loopback *gb);
247static void gb_loopback_check_attr(struct gb_loopback *gb)
248{
249 if (gb->us_wait > GB_LOOPBACK_US_WAIT_MAX)
250 gb->us_wait = GB_LOOPBACK_US_WAIT_MAX;
251 if (gb->size > gb_dev.size_max)
252 gb->size = gb_dev.size_max;
253 gb->requests_timedout = 0;
254 gb->requests_completed = 0;
255 gb->iteration_count = 0;
256 gb->send_count = 0;
257 gb->error = 0;
258
259 if (kfifo_depth < gb->iteration_max) {
260 dev_warn(gb->dev,
261 "cannot log bytes %u kfifo_depth %u\n",
262 gb->iteration_max, kfifo_depth);
263 }
264 kfifo_reset_out(&gb->kfifo_lat);
265 kfifo_reset_out(&gb->kfifo_ts);
266
267 switch (gb->type) {
268 case GB_LOOPBACK_TYPE_PING:
269 case GB_LOOPBACK_TYPE_TRANSFER:
270 case GB_LOOPBACK_TYPE_SINK:
271 gb->jiffy_timeout = usecs_to_jiffies(gb->timeout);
272 if (!gb->jiffy_timeout)
273 gb->jiffy_timeout = GB_LOOPBACK_TIMEOUT_MIN;
274 else if (gb->jiffy_timeout > GB_LOOPBACK_TIMEOUT_MAX)
275 gb->jiffy_timeout = GB_LOOPBACK_TIMEOUT_MAX;
276 gb_loopback_reset_stats(gb);
277 wake_up(&gb->wq);
278 break;
279 default:
280 gb->type = 0;
281 break;
282 }
283}
284
285/* Time to send and receive one message */
286gb_loopback_stats_attrs(latency);
287/* Number of requests sent per second on this cport */
288gb_loopback_stats_attrs(requests_per_second);
289/* Quantity of data sent and received on this cport */
290gb_loopback_stats_attrs(throughput);
291/* Latency across the UniPro link from APBridge's perspective */
292gb_loopback_stats_attrs(apbridge_unipro_latency);
293/* Firmware induced overhead in the GPBridge */
294gb_loopback_stats_attrs(gbphy_firmware_latency);
295
296/* Number of errors encountered during loop */
297gb_loopback_ro_attr(error);
298/* Number of requests successfully completed async */
299gb_loopback_ro_attr(requests_completed);
300/* Number of requests timed out async */
301gb_loopback_ro_attr(requests_timedout);
302/* Timeout minimum in useconds */
303gb_loopback_ro_attr(timeout_min);
304/* Timeout minimum in useconds */
305gb_loopback_ro_attr(timeout_max);
306
307/*
308 * Type of loopback message to send based on protocol type definitions
309 * 0 => Don't send message
310 * 2 => Send ping message continuously (message without payload)
311 * 3 => Send transfer message continuously (message with payload,
312 * payload returned in response)
313 * 4 => Send a sink message (message with payload, no payload in response)
314 */
315gb_dev_loopback_rw_attr(type, d);
316/* Size of transfer message payload: 0-4096 bytes */
317gb_dev_loopback_rw_attr(size, u);
318/* Time to wait between two messages: 0-1000 ms */
319gb_dev_loopback_rw_attr(us_wait, d);
320/* Maximum iterations for a given operation: 1-(2^32-1), 0 implies infinite */
321gb_dev_loopback_rw_attr(iteration_max, u);
322/* The current index of the for (i = 0; i < iteration_max; i++) loop */
323gb_dev_loopback_ro_attr(iteration_count, false);
324/* A flag to indicate synchronous or asynchronous operations */
325gb_dev_loopback_rw_attr(async, u);
326/* Timeout of an individual asynchronous request */
327gb_dev_loopback_rw_attr(timeout, u);
328/* Maximum number of in-flight operations before back-off */
329gb_dev_loopback_rw_attr(outstanding_operations_max, u);
330
331static struct attribute *loopback_attrs[] = {
332 &dev_attr_latency_min.attr,
333 &dev_attr_latency_max.attr,
334 &dev_attr_latency_avg.attr,
335 &dev_attr_requests_per_second_min.attr,
336 &dev_attr_requests_per_second_max.attr,
337 &dev_attr_requests_per_second_avg.attr,
338 &dev_attr_throughput_min.attr,
339 &dev_attr_throughput_max.attr,
340 &dev_attr_throughput_avg.attr,
341 &dev_attr_apbridge_unipro_latency_min.attr,
342 &dev_attr_apbridge_unipro_latency_max.attr,
343 &dev_attr_apbridge_unipro_latency_avg.attr,
344 &dev_attr_gbphy_firmware_latency_min.attr,
345 &dev_attr_gbphy_firmware_latency_max.attr,
346 &dev_attr_gbphy_firmware_latency_avg.attr,
347 &dev_attr_type.attr,
348 &dev_attr_size.attr,
349 &dev_attr_us_wait.attr,
350 &dev_attr_iteration_count.attr,
351 &dev_attr_iteration_max.attr,
352 &dev_attr_async.attr,
353 &dev_attr_error.attr,
354 &dev_attr_requests_completed.attr,
355 &dev_attr_requests_timedout.attr,
356 &dev_attr_timeout.attr,
357 &dev_attr_outstanding_operations_max.attr,
358 &dev_attr_timeout_min.attr,
359 &dev_attr_timeout_max.attr,
360 NULL,
361};
362ATTRIBUTE_GROUPS(loopback);
363
364static void gb_loopback_calculate_stats(struct gb_loopback *gb, bool error);
365
366static u32 gb_loopback_nsec_to_usec_latency(u64 elapsed_nsecs)
367{
368 u32 lat;
369
370 do_div(elapsed_nsecs, NSEC_PER_USEC);
371 lat = elapsed_nsecs;
372 return lat;
373}
374
375static u64 __gb_loopback_calc_latency(u64 t1, u64 t2)
376{
377 if (t2 > t1)
378 return t2 - t1;
379 else
380 return NSEC_PER_DAY - t2 + t1;
381}
382
383static u64 gb_loopback_calc_latency(struct timeval *ts, struct timeval *te)
384{
385 u64 t1, t2;
386
387 t1 = timeval_to_ns(ts);
388 t2 = timeval_to_ns(te);
389
390 return __gb_loopback_calc_latency(t1, t2);
391}
392
393static void gb_loopback_push_latency_ts(struct gb_loopback *gb,
394 struct timeval *ts, struct timeval *te)
395{
396 kfifo_in(&gb->kfifo_ts, (unsigned char *)ts, sizeof(*ts));
397 kfifo_in(&gb->kfifo_ts, (unsigned char *)te, sizeof(*te));
398}
399
400static int gb_loopback_operation_sync(struct gb_loopback *gb, int type,
401 void *request, int request_size,
402 void *response, int response_size)
403{
404 struct gb_operation *operation;
405 struct timeval ts, te;
406 int ret;
407
408 do_gettimeofday(&ts);
409 operation = gb_operation_create(gb->connection, type, request_size,
410 response_size, GFP_KERNEL);
411 if (!operation)
412 return -ENOMEM;
413
414 if (request_size)
415 memcpy(operation->request->payload, request, request_size);
416
417 ret = gb_operation_request_send_sync(operation);
418 if (ret) {
419 dev_err(&gb->connection->bundle->dev,
420 "synchronous operation failed: %d\n", ret);
421 goto out_put_operation;
422 } else {
423 if (response_size == operation->response->payload_size) {
424 memcpy(response, operation->response->payload,
425 response_size);
426 } else {
427 dev_err(&gb->connection->bundle->dev,
428 "response size %zu expected %d\n",
429 operation->response->payload_size,
430 response_size);
431 ret = -EINVAL;
432 goto out_put_operation;
433 }
434 }
435
436 do_gettimeofday(&te);
437
438 /* Calculate the total time the message took */
439 gb_loopback_push_latency_ts(gb, &ts, &te);
440 gb->elapsed_nsecs = gb_loopback_calc_latency(&ts, &te);
441
442out_put_operation:
443 gb_operation_put(operation);
444
445 return ret;
446}
447
448static void __gb_loopback_async_operation_destroy(struct kref *kref)
449{
450 struct gb_loopback_async_operation *op_async;
451
452 op_async = container_of(kref, struct gb_loopback_async_operation, kref);
453
454 list_del(&op_async->entry);
455 if (op_async->operation)
456 gb_operation_put(op_async->operation);
457 atomic_dec(&op_async->gb->outstanding_operations);
458 wake_up(&op_async->gb->wq_completion);
459 kfree(op_async);
460}
461
462static void gb_loopback_async_operation_get(struct gb_loopback_async_operation
463 *op_async)
464{
465 kref_get(&op_async->kref);
466}
467
468static void gb_loopback_async_operation_put(struct gb_loopback_async_operation
469 *op_async)
470{
471 unsigned long flags;
472
473 spin_lock_irqsave(&gb_dev.lock, flags);
474 kref_put(&op_async->kref, __gb_loopback_async_operation_destroy);
475 spin_unlock_irqrestore(&gb_dev.lock, flags);
476}
477
478static struct gb_loopback_async_operation *
479 gb_loopback_operation_find(u16 id)
480{
481 struct gb_loopback_async_operation *op_async;
482 bool found = false;
483 unsigned long flags;
484
485 spin_lock_irqsave(&gb_dev.lock, flags);
486 list_for_each_entry(op_async, &gb_dev.list_op_async, entry) {
487 if (op_async->operation->id == id) {
488 gb_loopback_async_operation_get(op_async);
489 found = true;
490 break;
491 }
492 }
493 spin_unlock_irqrestore(&gb_dev.lock, flags);
494
495 return found ? op_async : NULL;
496}
497
498static void gb_loopback_async_wait_all(struct gb_loopback *gb)
499{
500 wait_event(gb->wq_completion,
501 !atomic_read(&gb->outstanding_operations));
502}
503
504static void gb_loopback_async_operation_callback(struct gb_operation *operation)
505{
506 struct gb_loopback_async_operation *op_async;
507 struct gb_loopback *gb;
508 struct timeval te;
509 bool err = false;
510
511 do_gettimeofday(&te);
512 op_async = gb_loopback_operation_find(operation->id);
513 if (!op_async)
514 return;
515
516 gb = op_async->gb;
517 mutex_lock(&gb->mutex);
518
519 if (!op_async->pending || gb_operation_result(operation)) {
520 err = true;
521 } else {
522 if (op_async->completion)
523 if (op_async->completion(op_async))
524 err = true;
525 }
526
527 if (!err) {
528 gb_loopback_push_latency_ts(gb, &op_async->ts, &te);
529 gb->elapsed_nsecs = gb_loopback_calc_latency(&op_async->ts,
530 &te);
531 }
532
533 if (op_async->pending) {
534 if (err)
535 gb->error++;
536 gb->iteration_count++;
537 op_async->pending = false;
538 del_timer_sync(&op_async->timer);
539 gb_loopback_async_operation_put(op_async);
540 gb_loopback_calculate_stats(gb, err);
541 }
542 mutex_unlock(&gb->mutex);
543
544 dev_dbg(&gb->connection->bundle->dev, "complete operation %d\n",
545 operation->id);
546
547 gb_loopback_async_operation_put(op_async);
548}
549
550static void gb_loopback_async_operation_work(struct work_struct *work)
551{
552 struct gb_loopback *gb;
553 struct gb_operation *operation;
554 struct gb_loopback_async_operation *op_async;
555
556 op_async = container_of(work, struct gb_loopback_async_operation, work);
557 gb = op_async->gb;
558 operation = op_async->operation;
559
560 mutex_lock(&gb->mutex);
561 if (op_async->pending) {
562 gb->requests_timedout++;
563 gb->error++;
564 gb->iteration_count++;
565 op_async->pending = false;
566 gb_loopback_async_operation_put(op_async);
567 gb_loopback_calculate_stats(gb, true);
568 }
569 mutex_unlock(&gb->mutex);
570
571 dev_dbg(&gb->connection->bundle->dev, "timeout operation %d\n",
572 operation->id);
573
574 gb_operation_cancel(operation, -ETIMEDOUT);
575 gb_loopback_async_operation_put(op_async);
576}
577
578static void gb_loopback_async_operation_timeout(unsigned long data)
579{
580 struct gb_loopback_async_operation *op_async;
581 u16 id = data;
582
583 op_async = gb_loopback_operation_find(id);
584 if (!op_async) {
585 pr_err("operation %d not found - time out ?\n", id);
586 return;
587 }
588 schedule_work(&op_async->work);
589}
590
591static int gb_loopback_async_operation(struct gb_loopback *gb, int type,
592 void *request, int request_size,
593 int response_size,
594 void *completion)
595{
596 struct gb_loopback_async_operation *op_async;
597 struct gb_operation *operation;
598 int ret;
599 unsigned long flags;
600
601 op_async = kzalloc(sizeof(*op_async), GFP_KERNEL);
602 if (!op_async)
603 return -ENOMEM;
604
605 INIT_WORK(&op_async->work, gb_loopback_async_operation_work);
606 kref_init(&op_async->kref);
607
608 operation = gb_operation_create(gb->connection, type, request_size,
609 response_size, GFP_KERNEL);
610 if (!operation) {
611 kfree(op_async);
612 return -ENOMEM;
613 }
614
615 if (request_size)
616 memcpy(operation->request->payload, request, request_size);
617
618 op_async->gb = gb;
619 op_async->operation = operation;
620 op_async->completion = completion;
621
622 spin_lock_irqsave(&gb_dev.lock, flags);
623 list_add_tail(&op_async->entry, &gb_dev.list_op_async);
624 spin_unlock_irqrestore(&gb_dev.lock, flags);
625
626 do_gettimeofday(&op_async->ts);
627 op_async->pending = true;
628 atomic_inc(&gb->outstanding_operations);
629 mutex_lock(&gb->mutex);
630 ret = gb_operation_request_send(operation,
631 gb_loopback_async_operation_callback,
632 0,
633 GFP_KERNEL);
634 if (ret)
635 goto error;
636
637 setup_timer(&op_async->timer, gb_loopback_async_operation_timeout,
638 (unsigned long)operation->id);
639 op_async->timer.expires = jiffies + gb->jiffy_timeout;
640 add_timer(&op_async->timer);
641
642 goto done;
643error:
644 gb_loopback_async_operation_put(op_async);
645done:
646 mutex_unlock(&gb->mutex);
647 return ret;
648}
649
650static int gb_loopback_sync_sink(struct gb_loopback *gb, u32 len)
651{
652 struct gb_loopback_transfer_request *request;
653 int retval;
654
655 request = kmalloc(len + sizeof(*request), GFP_KERNEL);
656 if (!request)
657 return -ENOMEM;
658
659 request->len = cpu_to_le32(len);
660 retval = gb_loopback_operation_sync(gb, GB_LOOPBACK_TYPE_SINK,
661 request, len + sizeof(*request),
662 NULL, 0);
663 kfree(request);
664 return retval;
665}
666
667static int gb_loopback_sync_transfer(struct gb_loopback *gb, u32 len)
668{
669 struct gb_loopback_transfer_request *request;
670 struct gb_loopback_transfer_response *response;
671 int retval;
672
673 gb->apbridge_latency_ts = 0;
674 gb->gbphy_latency_ts = 0;
675
676 request = kmalloc(len + sizeof(*request), GFP_KERNEL);
677 if (!request)
678 return -ENOMEM;
679 response = kmalloc(len + sizeof(*response), GFP_KERNEL);
680 if (!response) {
681 kfree(request);
682 return -ENOMEM;
683 }
684
685 memset(request->data, 0x5A, len);
686
687 request->len = cpu_to_le32(len);
688 retval = gb_loopback_operation_sync(gb, GB_LOOPBACK_TYPE_TRANSFER,
689 request, len + sizeof(*request),
690 response, len + sizeof(*response));
691 if (retval)
692 goto gb_error;
693
694 if (memcmp(request->data, response->data, len)) {
695 dev_err(&gb->connection->bundle->dev,
696 "Loopback Data doesn't match\n");
697 retval = -EREMOTEIO;
698 }
699 gb->apbridge_latency_ts = (u32)__le32_to_cpu(response->reserved0);
700 gb->gbphy_latency_ts = (u32)__le32_to_cpu(response->reserved1);
701
702gb_error:
703 kfree(request);
704 kfree(response);
705
706 return retval;
707}
708
709static int gb_loopback_sync_ping(struct gb_loopback *gb)
710{
711 return gb_loopback_operation_sync(gb, GB_LOOPBACK_TYPE_PING,
712 NULL, 0, NULL, 0);
713}
714
715static int gb_loopback_async_sink(struct gb_loopback *gb, u32 len)
716{
717 struct gb_loopback_transfer_request *request;
718 int retval;
719
720 request = kmalloc(len + sizeof(*request), GFP_KERNEL);
721 if (!request)
722 return -ENOMEM;
723
724 request->len = cpu_to_le32(len);
725 retval = gb_loopback_async_operation(gb, GB_LOOPBACK_TYPE_SINK,
726 request, len + sizeof(*request),
727 0, NULL);
728 kfree(request);
729 return retval;
730}
731
732static int gb_loopback_async_transfer_complete(
733 struct gb_loopback_async_operation *op_async)
734{
735 struct gb_loopback *gb;
736 struct gb_operation *operation;
737 struct gb_loopback_transfer_request *request;
738 struct gb_loopback_transfer_response *response;
739 size_t len;
740 int retval = 0;
741
742 gb = op_async->gb;
743 operation = op_async->operation;
744 request = operation->request->payload;
745 response = operation->response->payload;
746 len = le32_to_cpu(request->len);
747
748 if (memcmp(request->data, response->data, len)) {
749 dev_err(&gb->connection->bundle->dev,
750 "Loopback Data doesn't match operation id %d\n",
751 operation->id);
752 retval = -EREMOTEIO;
753 } else {
754 gb->apbridge_latency_ts =
755 (u32)__le32_to_cpu(response->reserved0);
756 gb->gbphy_latency_ts =
757 (u32)__le32_to_cpu(response->reserved1);
758 }
759
760 return retval;
761}
762
763static int gb_loopback_async_transfer(struct gb_loopback *gb, u32 len)
764{
765 struct gb_loopback_transfer_request *request;
766 int retval, response_len;
767
768 request = kmalloc(len + sizeof(*request), GFP_KERNEL);
769 if (!request)
770 return -ENOMEM;
771
772 memset(request->data, 0x5A, len);
773
774 request->len = cpu_to_le32(len);
775 response_len = sizeof(struct gb_loopback_transfer_response);
776 retval = gb_loopback_async_operation(gb, GB_LOOPBACK_TYPE_TRANSFER,
777 request, len + sizeof(*request),
778 len + response_len,
779 gb_loopback_async_transfer_complete);
780 if (retval)
781 goto gb_error;
782
783gb_error:
784 kfree(request);
785 return retval;
786}
787
788static int gb_loopback_async_ping(struct gb_loopback *gb)
789{
790 return gb_loopback_async_operation(gb, GB_LOOPBACK_TYPE_PING,
791 NULL, 0, 0, NULL);
792}
793
794static int gb_loopback_request_handler(struct gb_operation *operation)
795{
796 struct gb_connection *connection = operation->connection;
797 struct gb_loopback_transfer_request *request;
798 struct gb_loopback_transfer_response *response;
799 struct device *dev = &connection->bundle->dev;
800 size_t len;
801
802 /* By convention, the AP initiates the version operation */
803 switch (operation->type) {
804 case GB_LOOPBACK_TYPE_PING:
805 case GB_LOOPBACK_TYPE_SINK:
806 return 0;
807 case GB_LOOPBACK_TYPE_TRANSFER:
808 if (operation->request->payload_size < sizeof(*request)) {
809 dev_err(dev, "transfer request too small (%zu < %zu)\n",
810 operation->request->payload_size,
811 sizeof(*request));
812 return -EINVAL; /* -EMSGSIZE */
813 }
814 request = operation->request->payload;
815 len = le32_to_cpu(request->len);
816 if (len > gb_dev.size_max) {
817 dev_err(dev, "transfer request too large (%zu > %zu)\n",
818 len, gb_dev.size_max);
819 return -EINVAL;
820 }
821
822 if (!gb_operation_response_alloc(operation,
823 len + sizeof(*response), GFP_KERNEL)) {
824 dev_err(dev, "error allocating response\n");
825 return -ENOMEM;
826 }
827 response = operation->response->payload;
828 response->len = cpu_to_le32(len);
829 if (len)
830 memcpy(response->data, request->data, len);
831
832 return 0;
833 default:
834 dev_err(dev, "unsupported request: %u\n", operation->type);
835 return -EINVAL;
836 }
837}
838
839static void gb_loopback_reset_stats(struct gb_loopback *gb)
840{
841 struct gb_loopback_stats reset = {
842 .min = U32_MAX,
843 };
844
845 /* Reset per-connection stats */
846 memcpy(&gb->latency, &reset,
847 sizeof(struct gb_loopback_stats));
848 memcpy(&gb->throughput, &reset,
849 sizeof(struct gb_loopback_stats));
850 memcpy(&gb->requests_per_second, &reset,
851 sizeof(struct gb_loopback_stats));
852 memcpy(&gb->apbridge_unipro_latency, &reset,
853 sizeof(struct gb_loopback_stats));
854 memcpy(&gb->gbphy_firmware_latency, &reset,
855 sizeof(struct gb_loopback_stats));
856
857 /* Should be initialized at least once per transaction set */
858 gb->apbridge_latency_ts = 0;
859 gb->gbphy_latency_ts = 0;
860 memset(&gb->ts, 0, sizeof(struct timeval));
861}
862
863static void gb_loopback_update_stats(struct gb_loopback_stats *stats, u32 val)
864{
865 if (stats->min > val)
866 stats->min = val;
867 if (stats->max < val)
868 stats->max = val;
869 stats->sum += val;
870 stats->count++;
871}
872
873static void gb_loopback_update_stats_window(struct gb_loopback_stats *stats,
874 u64 val, u32 count)
875{
876 stats->sum += val;
877 stats->count += count;
878
879 do_div(val, count);
880 if (stats->min > val)
881 stats->min = val;
882 if (stats->max < val)
883 stats->max = val;
884}
885
886static void gb_loopback_requests_update(struct gb_loopback *gb, u32 latency)
887{
888 u64 req = gb->requests_completed * USEC_PER_SEC;
889
890 gb_loopback_update_stats_window(&gb->requests_per_second, req, latency);
891}
892
893static void gb_loopback_throughput_update(struct gb_loopback *gb, u32 latency)
894{
895 u64 aggregate_size = sizeof(struct gb_operation_msg_hdr) * 2;
896
897 switch (gb->type) {
898 case GB_LOOPBACK_TYPE_PING:
899 break;
900 case GB_LOOPBACK_TYPE_SINK:
901 aggregate_size += sizeof(struct gb_loopback_transfer_request) +
902 gb->size;
903 break;
904 case GB_LOOPBACK_TYPE_TRANSFER:
905 aggregate_size += sizeof(struct gb_loopback_transfer_request) +
906 sizeof(struct gb_loopback_transfer_response) +
907 gb->size * 2;
908 break;
909 default:
910 return;
911 }
912
913 aggregate_size *= gb->requests_completed;
914 aggregate_size *= USEC_PER_SEC;
915 gb_loopback_update_stats_window(&gb->throughput, aggregate_size,
916 latency);
917}
918
919static void gb_loopback_calculate_latency_stats(struct gb_loopback *gb)
920{
921 u32 lat;
922
923 /* Express latency in terms of microseconds */
924 lat = gb_loopback_nsec_to_usec_latency(gb->elapsed_nsecs);
925
926 /* Log latency stastic */
927 gb_loopback_update_stats(&gb->latency, lat);
928
929 /* Raw latency log on a per thread basis */
930 kfifo_in(&gb->kfifo_lat, (unsigned char *)&lat, sizeof(lat));
931
932 /* Log the firmware supplied latency values */
933 gb_loopback_update_stats(&gb->apbridge_unipro_latency,
934 gb->apbridge_latency_ts);
935 gb_loopback_update_stats(&gb->gbphy_firmware_latency,
936 gb->gbphy_latency_ts);
937}
938
939static void gb_loopback_calculate_stats(struct gb_loopback *gb, bool error)
940{
941 u64 nlat;
942 u32 lat;
943 struct timeval te;
944
945 if (!error) {
946 gb->requests_completed++;
947 gb_loopback_calculate_latency_stats(gb);
948 }
949
950 do_gettimeofday(&te);
951 nlat = gb_loopback_calc_latency(&gb->ts, &te);
952 if (nlat >= NSEC_PER_SEC || gb->iteration_count == gb->iteration_max) {
953 lat = gb_loopback_nsec_to_usec_latency(nlat);
954
955 gb_loopback_throughput_update(gb, lat);
956 gb_loopback_requests_update(gb, lat);
957
958 if (gb->iteration_count != gb->iteration_max) {
959 gb->ts = te;
960 gb->requests_completed = 0;
961 }
962 }
963}
964
965static void gb_loopback_async_wait_to_send(struct gb_loopback *gb)
966{
967 if (!(gb->async && gb->outstanding_operations_max))
968 return;
969 wait_event_interruptible(gb->wq_completion,
970 (atomic_read(&gb->outstanding_operations) <
971 gb->outstanding_operations_max) ||
972 kthread_should_stop());
973}
974
975static int gb_loopback_fn(void *data)
976{
977 int error = 0;
978 int us_wait = 0;
979 int type;
980 int ret;
981 u32 size;
982
983 struct gb_loopback *gb = data;
984 struct gb_bundle *bundle = gb->connection->bundle;
985
986 ret = gb_pm_runtime_get_sync(bundle);
987 if (ret)
988 return ret;
989
990 while (1) {
991 if (!gb->type) {
992 gb_pm_runtime_put_autosuspend(bundle);
993 wait_event_interruptible(gb->wq, gb->type ||
994 kthread_should_stop());
995 ret = gb_pm_runtime_get_sync(bundle);
996 if (ret)
997 return ret;
998 }
999
1000 if (kthread_should_stop())
1001 break;
1002
1003 /* Limit the maximum number of in-flight async operations */
1004 gb_loopback_async_wait_to_send(gb);
1005 if (kthread_should_stop())
1006 break;
1007
1008 mutex_lock(&gb->mutex);
1009
1010 /* Optionally terminate */
1011 if (gb->send_count == gb->iteration_max) {
1012 mutex_unlock(&gb->mutex);
1013
1014 /* Wait for synchronous and asynchronus completion */
1015 gb_loopback_async_wait_all(gb);
1016
1017 /* Mark complete unless user-space has poked us */
1018 mutex_lock(&gb->mutex);
1019 if (gb->iteration_count == gb->iteration_max) {
1020 gb->type = 0;
1021 gb->send_count = 0;
1022 sysfs_notify(&gb->dev->kobj, NULL,
1023 "iteration_count");
1024 dev_dbg(&bundle->dev, "load test complete\n");
1025 } else {
1026 dev_dbg(&bundle->dev,
1027 "continuing on with new test set\n");
1028 }
1029 mutex_unlock(&gb->mutex);
1030 continue;
1031 }
1032 size = gb->size;
1033 us_wait = gb->us_wait;
1034 type = gb->type;
1035 if (gb->ts.tv_usec == 0 && gb->ts.tv_sec == 0)
1036 do_gettimeofday(&gb->ts);
1037 mutex_unlock(&gb->mutex);
1038
1039 /* Else operations to perform */
1040 if (gb->async) {
1041 if (type == GB_LOOPBACK_TYPE_PING)
1042 error = gb_loopback_async_ping(gb);
1043 else if (type == GB_LOOPBACK_TYPE_TRANSFER)
1044 error = gb_loopback_async_transfer(gb, size);
1045 else if (type == GB_LOOPBACK_TYPE_SINK)
1046 error = gb_loopback_async_sink(gb, size);
1047
1048 if (error)
1049 gb->error++;
1050 } else {
1051 /* We are effectively single threaded here */
1052 if (type == GB_LOOPBACK_TYPE_PING)
1053 error = gb_loopback_sync_ping(gb);
1054 else if (type == GB_LOOPBACK_TYPE_TRANSFER)
1055 error = gb_loopback_sync_transfer(gb, size);
1056 else if (type == GB_LOOPBACK_TYPE_SINK)
1057 error = gb_loopback_sync_sink(gb, size);
1058
1059 if (error)
1060 gb->error++;
1061 gb->iteration_count++;
1062 gb_loopback_calculate_stats(gb, !!error);
1063 }
1064 gb->send_count++;
1065
1066 if (us_wait) {
1067 if (us_wait < 20000)
1068 usleep_range(us_wait, us_wait + 100);
1069 else
1070 msleep(us_wait / 1000);
1071 }
1072 }
1073
1074 gb_pm_runtime_put_autosuspend(bundle);
1075
1076 return 0;
1077}
1078
1079static int gb_loopback_dbgfs_latency_show_common(struct seq_file *s,
1080 struct kfifo *kfifo,
1081 struct mutex *mutex)
1082{
1083 u32 latency;
1084 int retval;
1085
1086 if (kfifo_len(kfifo) == 0) {
1087 retval = -EAGAIN;
1088 goto done;
1089 }
1090
1091 mutex_lock(mutex);
1092 retval = kfifo_out(kfifo, &latency, sizeof(latency));
1093 if (retval > 0) {
1094 seq_printf(s, "%u", latency);
1095 retval = 0;
1096 }
1097 mutex_unlock(mutex);
1098done:
1099 return retval;
1100}
1101
1102static int gb_loopback_dbgfs_latency_show(struct seq_file *s, void *unused)
1103{
1104 struct gb_loopback *gb = s->private;
1105
1106 return gb_loopback_dbgfs_latency_show_common(s, &gb->kfifo_lat,
1107 &gb->mutex);
1108}
1109
1110static int gb_loopback_latency_open(struct inode *inode, struct file *file)
1111{
1112 return single_open(file, gb_loopback_dbgfs_latency_show,
1113 inode->i_private);
1114}
1115
1116static const struct file_operations gb_loopback_debugfs_latency_ops = {
1117 .open = gb_loopback_latency_open,
1118 .read = seq_read,
1119 .llseek = seq_lseek,
1120 .release = single_release,
1121};
1122
1123static int gb_loopback_bus_id_compare(void *priv, struct list_head *lha,
1124 struct list_head *lhb)
1125{
1126 struct gb_loopback *a = list_entry(lha, struct gb_loopback, entry);
1127 struct gb_loopback *b = list_entry(lhb, struct gb_loopback, entry);
1128 struct gb_connection *ca = a->connection;
1129 struct gb_connection *cb = b->connection;
1130
1131 if (ca->bundle->intf->interface_id < cb->bundle->intf->interface_id)
1132 return -1;
1133 if (cb->bundle->intf->interface_id < ca->bundle->intf->interface_id)
1134 return 1;
1135 if (ca->bundle->id < cb->bundle->id)
1136 return -1;
1137 if (cb->bundle->id < ca->bundle->id)
1138 return 1;
1139 if (ca->intf_cport_id < cb->intf_cport_id)
1140 return -1;
1141 else if (cb->intf_cport_id < ca->intf_cport_id)
1142 return 1;
1143
1144 return 0;
1145}
1146
1147static void gb_loopback_insert_id(struct gb_loopback *gb)
1148{
1149 struct gb_loopback *gb_list;
1150 u32 new_lbid = 0;
1151
1152 /* perform an insertion sort */
1153 list_add_tail(&gb->entry, &gb_dev.list);
1154 list_sort(NULL, &gb_dev.list, gb_loopback_bus_id_compare);
1155 list_for_each_entry(gb_list, &gb_dev.list, entry) {
1156 gb_list->lbid = 1 << new_lbid;
1157 new_lbid++;
1158 }
1159}
1160
1161#define DEBUGFS_NAMELEN 32
1162
1163static int gb_loopback_probe(struct gb_bundle *bundle,
1164 const struct greybus_bundle_id *id)
1165{
1166 struct greybus_descriptor_cport *cport_desc;
1167 struct gb_connection *connection;
1168 struct gb_loopback *gb;
1169 struct device *dev;
1170 int retval;
1171 char name[DEBUGFS_NAMELEN];
1172 unsigned long flags;
1173
1174 if (bundle->num_cports != 1)
1175 return -ENODEV;
1176
1177 cport_desc = &bundle->cport_desc[0];
1178 if (cport_desc->protocol_id != GREYBUS_PROTOCOL_LOOPBACK)
1179 return -ENODEV;
1180
1181 gb = kzalloc(sizeof(*gb), GFP_KERNEL);
1182 if (!gb)
1183 return -ENOMEM;
1184
1185 connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id),
1186 gb_loopback_request_handler);
1187 if (IS_ERR(connection)) {
1188 retval = PTR_ERR(connection);
1189 goto out_kzalloc;
1190 }
1191
1192 gb->connection = connection;
1193 greybus_set_drvdata(bundle, gb);
1194
1195 init_waitqueue_head(&gb->wq);
1196 init_waitqueue_head(&gb->wq_completion);
1197 atomic_set(&gb->outstanding_operations, 0);
1198 gb_loopback_reset_stats(gb);
1199
1200 /* Reported values to user-space for min/max timeouts */
1201 gb->timeout_min = jiffies_to_usecs(GB_LOOPBACK_TIMEOUT_MIN);
1202 gb->timeout_max = jiffies_to_usecs(GB_LOOPBACK_TIMEOUT_MAX);
1203
1204 if (!gb_dev.count) {
1205 /* Calculate maximum payload */
1206 gb_dev.size_max = gb_operation_get_payload_size_max(connection);
1207 if (gb_dev.size_max <=
1208 sizeof(struct gb_loopback_transfer_request)) {
1209 retval = -EINVAL;
1210 goto out_connection_destroy;
1211 }
1212 gb_dev.size_max -= sizeof(struct gb_loopback_transfer_request);
1213 }
1214
1215 /* Create per-connection sysfs and debugfs data-points */
1216 snprintf(name, sizeof(name), "raw_latency_%s",
1217 dev_name(&connection->bundle->dev));
1218 gb->file = debugfs_create_file(name, S_IFREG | 0444, gb_dev.root, gb,
1219 &gb_loopback_debugfs_latency_ops);
1220
1221 gb->id = ida_simple_get(&loopback_ida, 0, 0, GFP_KERNEL);
1222 if (gb->id < 0) {
1223 retval = gb->id;
1224 goto out_debugfs_remove;
1225 }
1226
1227 retval = gb_connection_enable(connection);
1228 if (retval)
1229 goto out_ida_remove;
1230
1231 dev = device_create_with_groups(&loopback_class,
1232 &connection->bundle->dev,
1233 MKDEV(0, 0), gb, loopback_groups,
1234 "gb_loopback%d", gb->id);
1235 if (IS_ERR(dev)) {
1236 retval = PTR_ERR(dev);
1237 goto out_connection_disable;
1238 }
1239 gb->dev = dev;
1240
1241 /* Allocate kfifo */
1242 if (kfifo_alloc(&gb->kfifo_lat, kfifo_depth * sizeof(u32),
1243 GFP_KERNEL)) {
1244 retval = -ENOMEM;
1245 goto out_conn;
1246 }
1247 if (kfifo_alloc(&gb->kfifo_ts, kfifo_depth * sizeof(struct timeval) * 2,
1248 GFP_KERNEL)) {
1249 retval = -ENOMEM;
1250 goto out_kfifo0;
1251 }
1252
1253 /* Fork worker thread */
1254 mutex_init(&gb->mutex);
1255 gb->task = kthread_run(gb_loopback_fn, gb, "gb_loopback");
1256 if (IS_ERR(gb->task)) {
1257 retval = PTR_ERR(gb->task);
1258 goto out_kfifo1;
1259 }
1260
1261 spin_lock_irqsave(&gb_dev.lock, flags);
1262 gb_loopback_insert_id(gb);
1263 gb_dev.count++;
1264 spin_unlock_irqrestore(&gb_dev.lock, flags);
1265
1266 gb_connection_latency_tag_enable(connection);
1267
1268 gb_pm_runtime_put_autosuspend(bundle);
1269
1270 return 0;
1271
1272out_kfifo1:
1273 kfifo_free(&gb->kfifo_ts);
1274out_kfifo0:
1275 kfifo_free(&gb->kfifo_lat);
1276out_conn:
1277 device_unregister(dev);
1278out_connection_disable:
1279 gb_connection_disable(connection);
1280out_ida_remove:
1281 ida_simple_remove(&loopback_ida, gb->id);
1282out_debugfs_remove:
1283 debugfs_remove(gb->file);
1284out_connection_destroy:
1285 gb_connection_destroy(connection);
1286out_kzalloc:
1287 kfree(gb);
1288
1289 return retval;
1290}
1291
1292static void gb_loopback_disconnect(struct gb_bundle *bundle)
1293{
1294 struct gb_loopback *gb = greybus_get_drvdata(bundle);
1295 unsigned long flags;
1296 int ret;
1297
1298 ret = gb_pm_runtime_get_sync(bundle);
1299 if (ret)
1300 gb_pm_runtime_get_noresume(bundle);
1301
1302 gb_connection_disable(gb->connection);
1303
1304 if (!IS_ERR_OR_NULL(gb->task))
1305 kthread_stop(gb->task);
1306
1307 kfifo_free(&gb->kfifo_lat);
1308 kfifo_free(&gb->kfifo_ts);
1309 gb_connection_latency_tag_disable(gb->connection);
1310 debugfs_remove(gb->file);
1311
1312 /*
1313 * FIXME: gb_loopback_async_wait_all() is redundant now, as connection
1314 * is disabled at the beginning and so we can't have any more
1315 * incoming/outgoing requests.
1316 */
1317 gb_loopback_async_wait_all(gb);
1318
1319 spin_lock_irqsave(&gb_dev.lock, flags);
1320 gb_dev.count--;
1321 list_del(&gb->entry);
1322 spin_unlock_irqrestore(&gb_dev.lock, flags);
1323
1324 device_unregister(gb->dev);
1325 ida_simple_remove(&loopback_ida, gb->id);
1326
1327 gb_connection_destroy(gb->connection);
1328 kfree(gb);
1329}
1330
1331static const struct greybus_bundle_id gb_loopback_id_table[] = {
1332 { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_LOOPBACK) },
1333 { }
1334};
1335MODULE_DEVICE_TABLE(greybus, gb_loopback_id_table);
1336
1337static struct greybus_driver gb_loopback_driver = {
1338 .name = "loopback",
1339 .probe = gb_loopback_probe,
1340 .disconnect = gb_loopback_disconnect,
1341 .id_table = gb_loopback_id_table,
1342};
1343
1344static int loopback_init(void)
1345{
1346 int retval;
1347
1348 INIT_LIST_HEAD(&gb_dev.list);
1349 INIT_LIST_HEAD(&gb_dev.list_op_async);
1350 spin_lock_init(&gb_dev.lock);
1351 gb_dev.root = debugfs_create_dir("gb_loopback", NULL);
1352
1353 retval = class_register(&loopback_class);
1354 if (retval)
1355 goto err;
1356
1357 retval = greybus_register(&gb_loopback_driver);
1358 if (retval)
1359 goto err_unregister;
1360
1361 return 0;
1362
1363err_unregister:
1364 class_unregister(&loopback_class);
1365err:
1366 debugfs_remove_recursive(gb_dev.root);
1367 return retval;
1368}
1369module_init(loopback_init);
1370
1371static void __exit loopback_exit(void)
1372{
1373 debugfs_remove_recursive(gb_dev.root);
1374 greybus_deregister(&gb_loopback_driver);
1375 class_unregister(&loopback_class);
1376 ida_destroy(&loopback_ida);
1377}
1378module_exit(loopback_exit);
1379
1380MODULE_LICENSE("GPL v2");
Linux 6.x block layer and io_uring tree(s)