1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
4 *
5 * Description: CoreSight Embedded Trace Buffer driver
6 */
7
8 #include <linux/atomic.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/types.h>
12 #include <linux/device.h>
13 #include <linux/io.h>
14 #include <linux/err.h>
15 #include <linux/fs.h>
16 #include <linux/miscdevice.h>
17 #include <linux/uaccess.h>
18 #include <linux/slab.h>
19 #include <linux/spinlock.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/seq_file.h>
22 #include <linux/coresight.h>
23 #include <linux/amba/bus.h>
24 #include <linux/clk.h>
25 #include <linux/circ_buf.h>
26 #include <linux/mm.h>
27 #include <linux/perf_event.h>
28
29
30 #include "coresight-priv.h"
31 #include "coresight-etm-perf.h"
32
33 #define ETB_RAM_DEPTH_REG 0x004
34 #define ETB_STATUS_REG 0x00c
35 #define ETB_RAM_READ_DATA_REG 0x010
36 #define ETB_RAM_READ_POINTER 0x014
37 #define ETB_RAM_WRITE_POINTER 0x018
38 #define ETB_TRG 0x01c
39 #define ETB_CTL_REG 0x020
40 #define ETB_RWD_REG 0x024
41 #define ETB_FFSR 0x300
42 #define ETB_FFCR 0x304
43 #define ETB_ITMISCOP0 0xee0
44 #define ETB_ITTRFLINACK 0xee4
45 #define ETB_ITTRFLIN 0xee8
46 #define ETB_ITATBDATA0 0xeeC
47 #define ETB_ITATBCTR2 0xef0
48 #define ETB_ITATBCTR1 0xef4
49 #define ETB_ITATBCTR0 0xef8
50
51 /* register description */
52 /* STS - 0x00C */
53 #define ETB_STATUS_RAM_FULL BIT(0)
54 /* CTL - 0x020 */
55 #define ETB_CTL_CAPT_EN BIT(0)
56 /* FFCR - 0x304 */
57 #define ETB_FFCR_EN_FTC BIT(0)
58 #define ETB_FFCR_FON_MAN BIT(6)
59 #define ETB_FFCR_STOP_FI BIT(12)
60 #define ETB_FFCR_STOP_TRIGGER BIT(13)
61
62 #define ETB_FFCR_BIT 6
63 #define ETB_FFSR_BIT 1
64 #define ETB_FRAME_SIZE_WORDS 4
65
66 DEFINE_CORESIGHT_DEVLIST(etb_devs, "etb");
67
68 /**
69 * struct etb_drvdata - specifics associated to an ETB component
70 * @base: memory mapped base address for this component.
71 * @atclk: optional clock for the core parts of the ETB.
72 * @csdev: component vitals needed by the framework.
73 * @miscdev: specifics to handle "/dev/xyz.etb" entry.
74 * @spinlock: only one at a time pls.
75 * @reading: synchronise user space access to etb buffer.
76 * @pid: Process ID of the process being monitored by the session
77 * that is using this component.
78 * @buf: area of memory where ETB buffer content gets sent.
79 * @mode: this ETB is being used.
80 * @buffer_depth: size of @buf.
81 * @trigger_cntr: amount of words to store after a trigger.
82 */
83 struct etb_drvdata {
84 void __iomem *base;
85 struct clk *atclk;
86 struct coresight_device *csdev;
87 struct miscdevice miscdev;
88 spinlock_t spinlock;
89 local_t reading;
90 pid_t pid;
91 u8 *buf;
92 u32 mode;
93 u32 buffer_depth;
94 u32 trigger_cntr;
95 };
96
97 static int etb_set_buffer(struct coresight_device *csdev,
98 struct perf_output_handle *handle);
99
etb_get_buffer_depth(struct etb_drvdata * drvdata)100 static inline unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata)
101 {
102 return readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
103 }
104
__etb_enable_hw(struct etb_drvdata * drvdata)105 static void __etb_enable_hw(struct etb_drvdata *drvdata)
106 {
107 int i;
108 u32 depth;
109
110 CS_UNLOCK(drvdata->base);
111
112 depth = drvdata->buffer_depth;
113 /* reset write RAM pointer address */
114 writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
115 /* clear entire RAM buffer */
116 for (i = 0; i < depth; i++)
117 writel_relaxed(0x0, drvdata->base + ETB_RWD_REG);
118
119 /* reset write RAM pointer address */
120 writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
121 /* reset read RAM pointer address */
122 writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
123
124 writel_relaxed(drvdata->trigger_cntr, drvdata->base + ETB_TRG);
125 writel_relaxed(ETB_FFCR_EN_FTC | ETB_FFCR_STOP_TRIGGER,
126 drvdata->base + ETB_FFCR);
127 /* ETB trace capture enable */
128 writel_relaxed(ETB_CTL_CAPT_EN, drvdata->base + ETB_CTL_REG);
129
130 CS_LOCK(drvdata->base);
131 }
132
etb_enable_hw(struct etb_drvdata * drvdata)133 static int etb_enable_hw(struct etb_drvdata *drvdata)
134 {
135 int rc = coresight_claim_device(drvdata->base);
136
137 if (rc)
138 return rc;
139
140 __etb_enable_hw(drvdata);
141 return 0;
142 }
143
etb_enable_sysfs(struct coresight_device * csdev)144 static int etb_enable_sysfs(struct coresight_device *csdev)
145 {
146 int ret = 0;
147 unsigned long flags;
148 struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
149
150 spin_lock_irqsave(&drvdata->spinlock, flags);
151
152 /* Don't messup with perf sessions. */
153 if (drvdata->mode == CS_MODE_PERF) {
154 ret = -EBUSY;
155 goto out;
156 }
157
158 if (drvdata->mode == CS_MODE_DISABLED) {
159 ret = etb_enable_hw(drvdata);
160 if (ret)
161 goto out;
162
163 drvdata->mode = CS_MODE_SYSFS;
164 }
165
166 atomic_inc(csdev->refcnt);
167 out:
168 spin_unlock_irqrestore(&drvdata->spinlock, flags);
169 return ret;
170 }
171
etb_enable_perf(struct coresight_device * csdev,void * data)172 static int etb_enable_perf(struct coresight_device *csdev, void *data)
173 {
174 int ret = 0;
175 pid_t pid;
176 unsigned long flags;
177 struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
178 struct perf_output_handle *handle = data;
179
180 spin_lock_irqsave(&drvdata->spinlock, flags);
181
182 /* No need to continue if the component is already in used by sysFS. */
183 if (drvdata->mode == CS_MODE_SYSFS) {
184 ret = -EBUSY;
185 goto out;
186 }
187
188 /* Get a handle on the pid of the process to monitor */
189 pid = task_pid_nr(handle->event->owner);
190
191 if (drvdata->pid != -1 && drvdata->pid != pid) {
192 ret = -EBUSY;
193 goto out;
194 }
195
196 /*
197 * No HW configuration is needed if the sink is already in
198 * use for this session.
199 */
200 if (drvdata->pid == pid) {
201 atomic_inc(csdev->refcnt);
202 goto out;
203 }
204
205 /*
206 * We don't have an internal state to clean up if we fail to setup
207 * the perf buffer. So we can perform the step before we turn the
208 * ETB on and leave without cleaning up.
209 */
210 ret = etb_set_buffer(csdev, handle);
211 if (ret)
212 goto out;
213
214 ret = etb_enable_hw(drvdata);
215 if (!ret) {
216 /* Associate with monitored process. */
217 drvdata->pid = pid;
218 drvdata->mode = CS_MODE_PERF;
219 atomic_inc(csdev->refcnt);
220 }
221
222 out:
223 spin_unlock_irqrestore(&drvdata->spinlock, flags);
224 return ret;
225 }
226
etb_enable(struct coresight_device * csdev,u32 mode,void * data)227 static int etb_enable(struct coresight_device *csdev, u32 mode, void *data)
228 {
229 int ret;
230
231 switch (mode) {
232 case CS_MODE_SYSFS:
233 ret = etb_enable_sysfs(csdev);
234 break;
235 case CS_MODE_PERF:
236 ret = etb_enable_perf(csdev, data);
237 break;
238 default:
239 ret = -EINVAL;
240 break;
241 }
242
243 if (ret)
244 return ret;
245
246 dev_dbg(&csdev->dev, "ETB enabled\n");
247 return 0;
248 }
249
__etb_disable_hw(struct etb_drvdata * drvdata)250 static void __etb_disable_hw(struct etb_drvdata *drvdata)
251 {
252 u32 ffcr;
253 struct device *dev = &drvdata->csdev->dev;
254
255 CS_UNLOCK(drvdata->base);
256
257 ffcr = readl_relaxed(drvdata->base + ETB_FFCR);
258 /* stop formatter when a stop has completed */
259 ffcr |= ETB_FFCR_STOP_FI;
260 writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
261 /* manually generate a flush of the system */
262 ffcr |= ETB_FFCR_FON_MAN;
263 writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
264
265 if (coresight_timeout(drvdata->base, ETB_FFCR, ETB_FFCR_BIT, 0)) {
266 dev_err(dev,
267 "timeout while waiting for completion of Manual Flush\n");
268 }
269
270 /* disable trace capture */
271 writel_relaxed(0x0, drvdata->base + ETB_CTL_REG);
272
273 if (coresight_timeout(drvdata->base, ETB_FFSR, ETB_FFSR_BIT, 1)) {
274 dev_err(dev,
275 "timeout while waiting for Formatter to Stop\n");
276 }
277
278 CS_LOCK(drvdata->base);
279 }
280
etb_dump_hw(struct etb_drvdata * drvdata)281 static void etb_dump_hw(struct etb_drvdata *drvdata)
282 {
283 bool lost = false;
284 int i;
285 u8 *buf_ptr;
286 u32 read_data, depth;
287 u32 read_ptr, write_ptr;
288 u32 frame_off, frame_endoff;
289 struct device *dev = &drvdata->csdev->dev;
290
291 CS_UNLOCK(drvdata->base);
292
293 read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
294 write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
295
296 frame_off = write_ptr % ETB_FRAME_SIZE_WORDS;
297 frame_endoff = ETB_FRAME_SIZE_WORDS - frame_off;
298 if (frame_off) {
299 dev_err(dev,
300 "write_ptr: %lu not aligned to formatter frame size\n",
301 (unsigned long)write_ptr);
302 dev_err(dev, "frameoff: %lu, frame_endoff: %lu\n",
303 (unsigned long)frame_off, (unsigned long)frame_endoff);
304 write_ptr += frame_endoff;
305 }
306
307 if ((readl_relaxed(drvdata->base + ETB_STATUS_REG)
308 & ETB_STATUS_RAM_FULL) == 0) {
309 writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
310 } else {
311 writel_relaxed(write_ptr, drvdata->base + ETB_RAM_READ_POINTER);
312 lost = true;
313 }
314
315 depth = drvdata->buffer_depth;
316 buf_ptr = drvdata->buf;
317 for (i = 0; i < depth; i++) {
318 read_data = readl_relaxed(drvdata->base +
319 ETB_RAM_READ_DATA_REG);
320 *(u32 *)buf_ptr = read_data;
321 buf_ptr += 4;
322 }
323
324 if (lost)
325 coresight_insert_barrier_packet(drvdata->buf);
326
327 if (frame_off) {
328 buf_ptr -= (frame_endoff * 4);
329 for (i = 0; i < frame_endoff; i++) {
330 *buf_ptr++ = 0x0;
331 *buf_ptr++ = 0x0;
332 *buf_ptr++ = 0x0;
333 *buf_ptr++ = 0x0;
334 }
335 }
336
337 writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
338
339 CS_LOCK(drvdata->base);
340 }
341
etb_disable_hw(struct etb_drvdata * drvdata)342 static void etb_disable_hw(struct etb_drvdata *drvdata)
343 {
344 __etb_disable_hw(drvdata);
345 etb_dump_hw(drvdata);
346 coresight_disclaim_device(drvdata->base);
347 }
348
etb_disable(struct coresight_device * csdev)349 static int etb_disable(struct coresight_device *csdev)
350 {
351 struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
352 unsigned long flags;
353
354 spin_lock_irqsave(&drvdata->spinlock, flags);
355
356 if (atomic_dec_return(csdev->refcnt)) {
357 spin_unlock_irqrestore(&drvdata->spinlock, flags);
358 return -EBUSY;
359 }
360
361 /* Complain if we (somehow) got out of sync */
362 WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
363 etb_disable_hw(drvdata);
364 /* Dissociate from monitored process. */
365 drvdata->pid = -1;
366 drvdata->mode = CS_MODE_DISABLED;
367 spin_unlock_irqrestore(&drvdata->spinlock, flags);
368
369 dev_dbg(&csdev->dev, "ETB disabled\n");
370 return 0;
371 }
372
etb_alloc_buffer(struct coresight_device * csdev,struct perf_event * event,void ** pages,int nr_pages,bool overwrite)373 static void *etb_alloc_buffer(struct coresight_device *csdev,
374 struct perf_event *event, void **pages,
375 int nr_pages, bool overwrite)
376 {
377 int node;
378 struct cs_buffers *buf;
379
380 node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);
381
382 buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
383 if (!buf)
384 return NULL;
385
386 buf->snapshot = overwrite;
387 buf->nr_pages = nr_pages;
388 buf->data_pages = pages;
389
390 return buf;
391 }
392
etb_free_buffer(void * config)393 static void etb_free_buffer(void *config)
394 {
395 struct cs_buffers *buf = config;
396
397 kfree(buf);
398 }
399
etb_set_buffer(struct coresight_device * csdev,struct perf_output_handle * handle)400 static int etb_set_buffer(struct coresight_device *csdev,
401 struct perf_output_handle *handle)
402 {
403 int ret = 0;
404 unsigned long head;
405 struct cs_buffers *buf = etm_perf_sink_config(handle);
406
407 if (!buf)
408 return -EINVAL;
409
410 /* wrap head around to the amount of space we have */
411 head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1);
412
413 /* find the page to write to */
414 buf->cur = head / PAGE_SIZE;
415
416 /* and offset within that page */
417 buf->offset = head % PAGE_SIZE;
418
419 local_set(&buf->data_size, 0);
420
421 return ret;
422 }
423
etb_update_buffer(struct coresight_device * csdev,struct perf_output_handle * handle,void * sink_config)424 static unsigned long etb_update_buffer(struct coresight_device *csdev,
425 struct perf_output_handle *handle,
426 void *sink_config)
427 {
428 bool lost = false;
429 int i, cur;
430 u8 *buf_ptr;
431 const u32 *barrier;
432 u32 read_ptr, write_ptr, capacity;
433 u32 status, read_data;
434 unsigned long offset, to_read = 0, flags;
435 struct cs_buffers *buf = sink_config;
436 struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
437
438 if (!buf)
439 return 0;
440
441 capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS;
442
443 spin_lock_irqsave(&drvdata->spinlock, flags);
444
445 /* Don't do anything if another tracer is using this sink */
446 if (atomic_read(csdev->refcnt) != 1)
447 goto out;
448
449 __etb_disable_hw(drvdata);
450 CS_UNLOCK(drvdata->base);
451
452 /* unit is in words, not bytes */
453 read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
454 write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
455
456 /*
457 * Entries should be aligned to the frame size. If they are not
458 * go back to the last alignment point to give decoding tools a
459 * chance to fix things.
460 */
461 if (write_ptr % ETB_FRAME_SIZE_WORDS) {
462 dev_err(&csdev->dev,
463 "write_ptr: %lu not aligned to formatter frame size\n",
464 (unsigned long)write_ptr);
465
466 write_ptr &= ~(ETB_FRAME_SIZE_WORDS - 1);
467 lost = true;
468 }
469
470 /*
471 * Get a hold of the status register and see if a wrap around
472 * has occurred. If so adjust things accordingly. Otherwise
473 * start at the beginning and go until the write pointer has
474 * been reached.
475 */
476 status = readl_relaxed(drvdata->base + ETB_STATUS_REG);
477 if (status & ETB_STATUS_RAM_FULL) {
478 lost = true;
479 to_read = capacity;
480 read_ptr = write_ptr;
481 } else {
482 to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->buffer_depth);
483 to_read *= ETB_FRAME_SIZE_WORDS;
484 }
485
486 /*
487 * Make sure we don't overwrite data that hasn't been consumed yet.
488 * It is entirely possible that the HW buffer has more data than the
489 * ring buffer can currently handle. If so adjust the start address
490 * to take only the last traces.
491 *
492 * In snapshot mode we are looking to get the latest traces only and as
493 * such, we don't care about not overwriting data that hasn't been
494 * processed by user space.
495 */
496 if (!buf->snapshot && to_read > handle->size) {
497 u32 mask = ~(ETB_FRAME_SIZE_WORDS - 1);
498
499 /* The new read pointer must be frame size aligned */
500 to_read = handle->size & mask;
501 /*
502 * Move the RAM read pointer up, keeping in mind that
503 * everything is in frame size units.
504 */
505 read_ptr = (write_ptr + drvdata->buffer_depth) -
506 to_read / ETB_FRAME_SIZE_WORDS;
507 /* Wrap around if need be*/
508 if (read_ptr > (drvdata->buffer_depth - 1))
509 read_ptr -= drvdata->buffer_depth;
510 /* let the decoder know we've skipped ahead */
511 lost = true;
512 }
513
514 /*
515 * Don't set the TRUNCATED flag in snapshot mode because 1) the
516 * captured buffer is expected to be truncated and 2) a full buffer
517 * prevents the event from being re-enabled by the perf core,
518 * resulting in stale data being send to user space.
519 */
520 if (!buf->snapshot && lost)
521 perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
522
523 /* finally tell HW where we want to start reading from */
524 writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
525
526 cur = buf->cur;
527 offset = buf->offset;
528 barrier = barrier_pkt;
529
530 for (i = 0; i < to_read; i += 4) {
531 buf_ptr = buf->data_pages[cur] + offset;
532 read_data = readl_relaxed(drvdata->base +
533 ETB_RAM_READ_DATA_REG);
534 if (lost && i < CORESIGHT_BARRIER_PKT_SIZE) {
535 read_data = *barrier;
536 barrier++;
537 }
538
539 *(u32 *)buf_ptr = read_data;
540 buf_ptr += 4;
541
542 offset += 4;
543 if (offset >= PAGE_SIZE) {
544 offset = 0;
545 cur++;
546 /* wrap around at the end of the buffer */
547 cur &= buf->nr_pages - 1;
548 }
549 }
550
551 /* reset ETB buffer for next run */
552 writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
553 writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
554
555 /*
556 * In snapshot mode we simply increment the head by the number of byte
557 * that were written. User space function cs_etm_find_snapshot() will
558 * figure out how many bytes to get from the AUX buffer based on the
559 * position of the head.
560 */
561 if (buf->snapshot)
562 handle->head += to_read;
563
564 __etb_enable_hw(drvdata);
565 CS_LOCK(drvdata->base);
566 out:
567 spin_unlock_irqrestore(&drvdata->spinlock, flags);
568
569 return to_read;
570 }
571
572 static const struct coresight_ops_sink etb_sink_ops = {
573 .enable = etb_enable,
574 .disable = etb_disable,
575 .alloc_buffer = etb_alloc_buffer,
576 .free_buffer = etb_free_buffer,
577 .update_buffer = etb_update_buffer,
578 };
579
580 static const struct coresight_ops etb_cs_ops = {
581 .sink_ops = &etb_sink_ops,
582 };
583
etb_dump(struct etb_drvdata * drvdata)584 static void etb_dump(struct etb_drvdata *drvdata)
585 {
586 unsigned long flags;
587
588 spin_lock_irqsave(&drvdata->spinlock, flags);
589 if (drvdata->mode == CS_MODE_SYSFS) {
590 __etb_disable_hw(drvdata);
591 etb_dump_hw(drvdata);
592 __etb_enable_hw(drvdata);
593 }
594 spin_unlock_irqrestore(&drvdata->spinlock, flags);
595
596 dev_dbg(&drvdata->csdev->dev, "ETB dumped\n");
597 }
598
etb_open(struct inode * inode,struct file * file)599 static int etb_open(struct inode *inode, struct file *file)
600 {
601 struct etb_drvdata *drvdata = container_of(file->private_data,
602 struct etb_drvdata, miscdev);
603
604 if (local_cmpxchg(&drvdata->reading, 0, 1))
605 return -EBUSY;
606
607 dev_dbg(&drvdata->csdev->dev, "%s: successfully opened\n", __func__);
608 return 0;
609 }
610
etb_read(struct file * file,char __user * data,size_t len,loff_t * ppos)611 static ssize_t etb_read(struct file *file, char __user *data,
612 size_t len, loff_t *ppos)
613 {
614 u32 depth;
615 struct etb_drvdata *drvdata = container_of(file->private_data,
616 struct etb_drvdata, miscdev);
617 struct device *dev = &drvdata->csdev->dev;
618
619 etb_dump(drvdata);
620
621 depth = drvdata->buffer_depth;
622 if (*ppos + len > depth * 4)
623 len = depth * 4 - *ppos;
624
625 if (copy_to_user(data, drvdata->buf + *ppos, len)) {
626 dev_dbg(dev,
627 "%s: copy_to_user failed\n", __func__);
628 return -EFAULT;
629 }
630
631 *ppos += len;
632
633 dev_dbg(dev, "%s: %zu bytes copied, %d bytes left\n",
634 __func__, len, (int)(depth * 4 - *ppos));
635 return len;
636 }
637
etb_release(struct inode * inode,struct file * file)638 static int etb_release(struct inode *inode, struct file *file)
639 {
640 struct etb_drvdata *drvdata = container_of(file->private_data,
641 struct etb_drvdata, miscdev);
642 local_set(&drvdata->reading, 0);
643
644 dev_dbg(&drvdata->csdev->dev, "%s: released\n", __func__);
645 return 0;
646 }
647
648 static const struct file_operations etb_fops = {
649 .owner = THIS_MODULE,
650 .open = etb_open,
651 .read = etb_read,
652 .release = etb_release,
653 .llseek = no_llseek,
654 };
655
656 #define coresight_etb10_reg(name, offset) \
657 coresight_simple_reg32(struct etb_drvdata, name, offset)
658
659 coresight_etb10_reg(rdp, ETB_RAM_DEPTH_REG);
660 coresight_etb10_reg(sts, ETB_STATUS_REG);
661 coresight_etb10_reg(rrp, ETB_RAM_READ_POINTER);
662 coresight_etb10_reg(rwp, ETB_RAM_WRITE_POINTER);
663 coresight_etb10_reg(trg, ETB_TRG);
664 coresight_etb10_reg(ctl, ETB_CTL_REG);
665 coresight_etb10_reg(ffsr, ETB_FFSR);
666 coresight_etb10_reg(ffcr, ETB_FFCR);
667
668 static struct attribute *coresight_etb_mgmt_attrs[] = {
669 &dev_attr_rdp.attr,
670 &dev_attr_sts.attr,
671 &dev_attr_rrp.attr,
672 &dev_attr_rwp.attr,
673 &dev_attr_trg.attr,
674 &dev_attr_ctl.attr,
675 &dev_attr_ffsr.attr,
676 &dev_attr_ffcr.attr,
677 NULL,
678 };
679
trigger_cntr_show(struct device * dev,struct device_attribute * attr,char * buf)680 static ssize_t trigger_cntr_show(struct device *dev,
681 struct device_attribute *attr, char *buf)
682 {
683 struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
684 unsigned long val = drvdata->trigger_cntr;
685
686 return sprintf(buf, "%#lx\n", val);
687 }
688
trigger_cntr_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)689 static ssize_t trigger_cntr_store(struct device *dev,
690 struct device_attribute *attr,
691 const char *buf, size_t size)
692 {
693 int ret;
694 unsigned long val;
695 struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
696
697 ret = kstrtoul(buf, 16, &val);
698 if (ret)
699 return ret;
700
701 drvdata->trigger_cntr = val;
702 return size;
703 }
704 static DEVICE_ATTR_RW(trigger_cntr);
705
706 static struct attribute *coresight_etb_attrs[] = {
707 &dev_attr_trigger_cntr.attr,
708 NULL,
709 };
710
711 static const struct attribute_group coresight_etb_group = {
712 .attrs = coresight_etb_attrs,
713 };
714
715 static const struct attribute_group coresight_etb_mgmt_group = {
716 .attrs = coresight_etb_mgmt_attrs,
717 .name = "mgmt",
718 };
719
720 const struct attribute_group *coresight_etb_groups[] = {
721 &coresight_etb_group,
722 &coresight_etb_mgmt_group,
723 NULL,
724 };
725
etb_probe(struct amba_device * adev,const struct amba_id * id)726 static int etb_probe(struct amba_device *adev, const struct amba_id *id)
727 {
728 int ret;
729 void __iomem *base;
730 struct device *dev = &adev->dev;
731 struct coresight_platform_data *pdata = NULL;
732 struct etb_drvdata *drvdata;
733 struct resource *res = &adev->res;
734 struct coresight_desc desc = { 0 };
735
736 desc.name = coresight_alloc_device_name(&etb_devs, dev);
737 if (!desc.name)
738 return -ENOMEM;
739
740 drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
741 if (!drvdata)
742 return -ENOMEM;
743
744 drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
745 if (!IS_ERR(drvdata->atclk)) {
746 ret = clk_prepare_enable(drvdata->atclk);
747 if (ret)
748 return ret;
749 }
750 dev_set_drvdata(dev, drvdata);
751
752 /* validity for the resource is already checked by the AMBA core */
753 base = devm_ioremap_resource(dev, res);
754 if (IS_ERR(base))
755 return PTR_ERR(base);
756
757 drvdata->base = base;
758
759 spin_lock_init(&drvdata->spinlock);
760
761 drvdata->buffer_depth = etb_get_buffer_depth(drvdata);
762
763 if (drvdata->buffer_depth & 0x80000000)
764 return -EINVAL;
765
766 drvdata->buf = devm_kcalloc(dev,
767 drvdata->buffer_depth, 4, GFP_KERNEL);
768 if (!drvdata->buf)
769 return -ENOMEM;
770
771 /* This device is not associated with a session */
772 drvdata->pid = -1;
773
774 pdata = coresight_get_platform_data(dev);
775 if (IS_ERR(pdata))
776 return PTR_ERR(pdata);
777 adev->dev.platform_data = pdata;
778
779 desc.type = CORESIGHT_DEV_TYPE_SINK;
780 desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
781 desc.ops = &etb_cs_ops;
782 desc.pdata = pdata;
783 desc.dev = dev;
784 desc.groups = coresight_etb_groups;
785 drvdata->csdev = coresight_register(&desc);
786 if (IS_ERR(drvdata->csdev))
787 return PTR_ERR(drvdata->csdev);
788
789 drvdata->miscdev.name = desc.name;
790 drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
791 drvdata->miscdev.fops = &etb_fops;
792 ret = misc_register(&drvdata->miscdev);
793 if (ret)
794 goto err_misc_register;
795
796 pm_runtime_put(&adev->dev);
797 return 0;
798
799 err_misc_register:
800 coresight_unregister(drvdata->csdev);
801 return ret;
802 }
803
804 #ifdef CONFIG_PM
etb_runtime_suspend(struct device * dev)805 static int etb_runtime_suspend(struct device *dev)
806 {
807 struct etb_drvdata *drvdata = dev_get_drvdata(dev);
808
809 if (drvdata && !IS_ERR(drvdata->atclk))
810 clk_disable_unprepare(drvdata->atclk);
811
812 return 0;
813 }
814
etb_runtime_resume(struct device * dev)815 static int etb_runtime_resume(struct device *dev)
816 {
817 struct etb_drvdata *drvdata = dev_get_drvdata(dev);
818
819 if (drvdata && !IS_ERR(drvdata->atclk))
820 clk_prepare_enable(drvdata->atclk);
821
822 return 0;
823 }
824 #endif
825
826 static const struct dev_pm_ops etb_dev_pm_ops = {
827 SET_RUNTIME_PM_OPS(etb_runtime_suspend, etb_runtime_resume, NULL)
828 };
829
830 static const struct amba_id etb_ids[] = {
831 {
832 .id = 0x000bb907,
833 .mask = 0x000fffff,
834 },
835 { 0, 0},
836 };
837
838 static struct amba_driver etb_driver = {
839 .drv = {
840 .name = "coresight-etb10",
841 .owner = THIS_MODULE,
842 .pm = &etb_dev_pm_ops,
843 .suppress_bind_attrs = true,
844
845 },
846 .probe = etb_probe,
847 .id_table = etb_ids,
848 };
849 builtin_amba_driver(etb_driver);
850