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1/* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
2 *
3 * Description: CoreSight Embedded Trace Buffer driver
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 and
7 * only version 2 as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14
15#include <asm/local.h>
16#include <linux/kernel.h>
17#include <linux/init.h>
18#include <linux/types.h>
19#include <linux/device.h>
20#include <linux/io.h>
21#include <linux/err.h>
22#include <linux/fs.h>
23#include <linux/miscdevice.h>
24#include <linux/uaccess.h>
25#include <linux/slab.h>
26#include <linux/spinlock.h>
27#include <linux/pm_runtime.h>
28#include <linux/seq_file.h>
29#include <linux/coresight.h>
30#include <linux/amba/bus.h>
31#include <linux/clk.h>
32#include <linux/circ_buf.h>
33#include <linux/mm.h>
34#include <linux/perf_event.h>
35
36
37#include "coresight-priv.h"
38
39#define ETB_RAM_DEPTH_REG 0x004
40#define ETB_STATUS_REG 0x00c
41#define ETB_RAM_READ_DATA_REG 0x010
42#define ETB_RAM_READ_POINTER 0x014
43#define ETB_RAM_WRITE_POINTER 0x018
44#define ETB_TRG 0x01c
45#define ETB_CTL_REG 0x020
46#define ETB_RWD_REG 0x024
47#define ETB_FFSR 0x300
48#define ETB_FFCR 0x304
49#define ETB_ITMISCOP0 0xee0
50#define ETB_ITTRFLINACK 0xee4
51#define ETB_ITTRFLIN 0xee8
52#define ETB_ITATBDATA0 0xeeC
53#define ETB_ITATBCTR2 0xef0
54#define ETB_ITATBCTR1 0xef4
55#define ETB_ITATBCTR0 0xef8
56
57/* register description */
58/* STS - 0x00C */
59#define ETB_STATUS_RAM_FULL BIT(0)
60/* CTL - 0x020 */
61#define ETB_CTL_CAPT_EN BIT(0)
62/* FFCR - 0x304 */
63#define ETB_FFCR_EN_FTC BIT(0)
64#define ETB_FFCR_FON_MAN BIT(6)
65#define ETB_FFCR_STOP_FI BIT(12)
66#define ETB_FFCR_STOP_TRIGGER BIT(13)
67
68#define ETB_FFCR_BIT 6
69#define ETB_FFSR_BIT 1
70#define ETB_FRAME_SIZE_WORDS 4
71
72/**
73 * struct etb_drvdata - specifics associated to an ETB component
74 * @base: memory mapped base address for this component.
75 * @dev: the device entity associated to this component.
76 * @atclk: optional clock for the core parts of the ETB.
77 * @csdev: component vitals needed by the framework.
78 * @miscdev: specifics to handle "/dev/xyz.etb" entry.
79 * @spinlock: only one at a time pls.
80 * @reading: synchronise user space access to etb buffer.
81 * @mode: this ETB is being used.
82 * @buf: area of memory where ETB buffer content gets sent.
83 * @buffer_depth: size of @buf.
84 * @trigger_cntr: amount of words to store after a trigger.
85 */
86struct etb_drvdata {
87 void __iomem *base;
88 struct device *dev;
89 struct clk *atclk;
90 struct coresight_device *csdev;
91 struct miscdevice miscdev;
92 spinlock_t spinlock;
93 local_t reading;
94 local_t mode;
95 u8 *buf;
96 u32 buffer_depth;
97 u32 trigger_cntr;
98};
99
100static unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata)
101{
102 u32 depth = 0;
103
104 pm_runtime_get_sync(drvdata->dev);
105
106 /* RO registers don't need locking */
107 depth = readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
108
109 pm_runtime_put(drvdata->dev);
110 return depth;
111}
112
113static void etb_enable_hw(struct etb_drvdata *drvdata)
114{
115 int i;
116 u32 depth;
117
118 CS_UNLOCK(drvdata->base);
119
120 depth = drvdata->buffer_depth;
121 /* reset write RAM pointer address */
122 writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
123 /* clear entire RAM buffer */
124 for (i = 0; i < depth; i++)
125 writel_relaxed(0x0, drvdata->base + ETB_RWD_REG);
126
127 /* reset write RAM pointer address */
128 writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
129 /* reset read RAM pointer address */
130 writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
131
132 writel_relaxed(drvdata->trigger_cntr, drvdata->base + ETB_TRG);
133 writel_relaxed(ETB_FFCR_EN_FTC | ETB_FFCR_STOP_TRIGGER,
134 drvdata->base + ETB_FFCR);
135 /* ETB trace capture enable */
136 writel_relaxed(ETB_CTL_CAPT_EN, drvdata->base + ETB_CTL_REG);
137
138 CS_LOCK(drvdata->base);
139}
140
141static int etb_enable(struct coresight_device *csdev, u32 mode)
142{
143 u32 val;
144 unsigned long flags;
145 struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
146
147 val = local_cmpxchg(&drvdata->mode,
148 CS_MODE_DISABLED, mode);
149 /*
150 * When accessing from Perf, a HW buffer can be handled
151 * by a single trace entity. In sysFS mode many tracers
152 * can be logging to the same HW buffer.
153 */
154 if (val == CS_MODE_PERF)
155 return -EBUSY;
156
157 /* Nothing to do, the tracer is already enabled. */
158 if (val == CS_MODE_SYSFS)
159 goto out;
160
161 spin_lock_irqsave(&drvdata->spinlock, flags);
162 etb_enable_hw(drvdata);
163 spin_unlock_irqrestore(&drvdata->spinlock, flags);
164
165out:
166 dev_info(drvdata->dev, "ETB enabled\n");
167 return 0;
168}
169
170static void etb_disable_hw(struct etb_drvdata *drvdata)
171{
172 u32 ffcr;
173
174 CS_UNLOCK(drvdata->base);
175
176 ffcr = readl_relaxed(drvdata->base + ETB_FFCR);
177 /* stop formatter when a stop has completed */
178 ffcr |= ETB_FFCR_STOP_FI;
179 writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
180 /* manually generate a flush of the system */
181 ffcr |= ETB_FFCR_FON_MAN;
182 writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
183
184 if (coresight_timeout(drvdata->base, ETB_FFCR, ETB_FFCR_BIT, 0)) {
185 dev_err(drvdata->dev,
186 "timeout while waiting for completion of Manual Flush\n");
187 }
188
189 /* disable trace capture */
190 writel_relaxed(0x0, drvdata->base + ETB_CTL_REG);
191
192 if (coresight_timeout(drvdata->base, ETB_FFSR, ETB_FFSR_BIT, 1)) {
193 dev_err(drvdata->dev,
194 "timeout while waiting for Formatter to Stop\n");
195 }
196
197 CS_LOCK(drvdata->base);
198}
199
200static void etb_dump_hw(struct etb_drvdata *drvdata)
201{
202 bool lost = false;
203 int i;
204 u8 *buf_ptr;
205 const u32 *barrier;
206 u32 read_data, depth;
207 u32 read_ptr, write_ptr;
208 u32 frame_off, frame_endoff;
209
210 CS_UNLOCK(drvdata->base);
211
212 read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
213 write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
214
215 frame_off = write_ptr % ETB_FRAME_SIZE_WORDS;
216 frame_endoff = ETB_FRAME_SIZE_WORDS - frame_off;
217 if (frame_off) {
218 dev_err(drvdata->dev,
219 "write_ptr: %lu not aligned to formatter frame size\n",
220 (unsigned long)write_ptr);
221 dev_err(drvdata->dev, "frameoff: %lu, frame_endoff: %lu\n",
222 (unsigned long)frame_off, (unsigned long)frame_endoff);
223 write_ptr += frame_endoff;
224 }
225
226 if ((readl_relaxed(drvdata->base + ETB_STATUS_REG)
227 & ETB_STATUS_RAM_FULL) == 0) {
228 writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
229 } else {
230 writel_relaxed(write_ptr, drvdata->base + ETB_RAM_READ_POINTER);
231 lost = true;
232 }
233
234 depth = drvdata->buffer_depth;
235 buf_ptr = drvdata->buf;
236 barrier = barrier_pkt;
237 for (i = 0; i < depth; i++) {
238 read_data = readl_relaxed(drvdata->base +
239 ETB_RAM_READ_DATA_REG);
240 if (lost && *barrier) {
241 read_data = *barrier;
242 barrier++;
243 }
244
245 *(u32 *)buf_ptr = read_data;
246 buf_ptr += 4;
247 }
248
249 if (frame_off) {
250 buf_ptr -= (frame_endoff * 4);
251 for (i = 0; i < frame_endoff; i++) {
252 *buf_ptr++ = 0x0;
253 *buf_ptr++ = 0x0;
254 *buf_ptr++ = 0x0;
255 *buf_ptr++ = 0x0;
256 }
257 }
258
259 writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
260
261 CS_LOCK(drvdata->base);
262}
263
264static void etb_disable(struct coresight_device *csdev)
265{
266 struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
267 unsigned long flags;
268
269 spin_lock_irqsave(&drvdata->spinlock, flags);
270 etb_disable_hw(drvdata);
271 etb_dump_hw(drvdata);
272 spin_unlock_irqrestore(&drvdata->spinlock, flags);
273
274 local_set(&drvdata->mode, CS_MODE_DISABLED);
275
276 dev_info(drvdata->dev, "ETB disabled\n");
277}
278
279static void *etb_alloc_buffer(struct coresight_device *csdev, int cpu,
280 void **pages, int nr_pages, bool overwrite)
281{
282 int node;
283 struct cs_buffers *buf;
284
285 if (cpu == -1)
286 cpu = smp_processor_id();
287 node = cpu_to_node(cpu);
288
289 buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
290 if (!buf)
291 return NULL;
292
293 buf->snapshot = overwrite;
294 buf->nr_pages = nr_pages;
295 buf->data_pages = pages;
296
297 return buf;
298}
299
300static void etb_free_buffer(void *config)
301{
302 struct cs_buffers *buf = config;
303
304 kfree(buf);
305}
306
307static int etb_set_buffer(struct coresight_device *csdev,
308 struct perf_output_handle *handle,
309 void *sink_config)
310{
311 int ret = 0;
312 unsigned long head;
313 struct cs_buffers *buf = sink_config;
314
315 /* wrap head around to the amount of space we have */
316 head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1);
317
318 /* find the page to write to */
319 buf->cur = head / PAGE_SIZE;
320
321 /* and offset within that page */
322 buf->offset = head % PAGE_SIZE;
323
324 local_set(&buf->data_size, 0);
325
326 return ret;
327}
328
329static unsigned long etb_reset_buffer(struct coresight_device *csdev,
330 struct perf_output_handle *handle,
331 void *sink_config)
332{
333 unsigned long size = 0;
334 struct cs_buffers *buf = sink_config;
335
336 if (buf) {
337 /*
338 * In snapshot mode ->data_size holds the new address of the
339 * ring buffer's head. The size itself is the whole address
340 * range since we want the latest information.
341 */
342 if (buf->snapshot)
343 handle->head = local_xchg(&buf->data_size,
344 buf->nr_pages << PAGE_SHIFT);
345
346 /*
347 * Tell the tracer PMU how much we got in this run and if
348 * something went wrong along the way. Nobody else can use
349 * this cs_buffers instance until we are done. As such
350 * resetting parameters here and squaring off with the ring
351 * buffer API in the tracer PMU is fine.
352 */
353 size = local_xchg(&buf->data_size, 0);
354 }
355
356 return size;
357}
358
359static void etb_update_buffer(struct coresight_device *csdev,
360 struct perf_output_handle *handle,
361 void *sink_config)
362{
363 bool lost = false;
364 int i, cur;
365 u8 *buf_ptr;
366 const u32 *barrier;
367 u32 read_ptr, write_ptr, capacity;
368 u32 status, read_data, to_read;
369 unsigned long offset;
370 struct cs_buffers *buf = sink_config;
371 struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
372
373 if (!buf)
374 return;
375
376 capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS;
377
378 etb_disable_hw(drvdata);
379 CS_UNLOCK(drvdata->base);
380
381 /* unit is in words, not bytes */
382 read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
383 write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
384
385 /*
386 * Entries should be aligned to the frame size. If they are not
387 * go back to the last alignment point to give decoding tools a
388 * chance to fix things.
389 */
390 if (write_ptr % ETB_FRAME_SIZE_WORDS) {
391 dev_err(drvdata->dev,
392 "write_ptr: %lu not aligned to formatter frame size\n",
393 (unsigned long)write_ptr);
394
395 write_ptr &= ~(ETB_FRAME_SIZE_WORDS - 1);
396 lost = true;
397 }
398
399 /*
400 * Get a hold of the status register and see if a wrap around
401 * has occurred. If so adjust things accordingly. Otherwise
402 * start at the beginning and go until the write pointer has
403 * been reached.
404 */
405 status = readl_relaxed(drvdata->base + ETB_STATUS_REG);
406 if (status & ETB_STATUS_RAM_FULL) {
407 lost = true;
408 to_read = capacity;
409 read_ptr = write_ptr;
410 } else {
411 to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->buffer_depth);
412 to_read *= ETB_FRAME_SIZE_WORDS;
413 }
414
415 /*
416 * Make sure we don't overwrite data that hasn't been consumed yet.
417 * It is entirely possible that the HW buffer has more data than the
418 * ring buffer can currently handle. If so adjust the start address
419 * to take only the last traces.
420 *
421 * In snapshot mode we are looking to get the latest traces only and as
422 * such, we don't care about not overwriting data that hasn't been
423 * processed by user space.
424 */
425 if (!buf->snapshot && to_read > handle->size) {
426 u32 mask = ~(ETB_FRAME_SIZE_WORDS - 1);
427
428 /* The new read pointer must be frame size aligned */
429 to_read = handle->size & mask;
430 /*
431 * Move the RAM read pointer up, keeping in mind that
432 * everything is in frame size units.
433 */
434 read_ptr = (write_ptr + drvdata->buffer_depth) -
435 to_read / ETB_FRAME_SIZE_WORDS;
436 /* Wrap around if need be*/
437 if (read_ptr > (drvdata->buffer_depth - 1))
438 read_ptr -= drvdata->buffer_depth;
439 /* let the decoder know we've skipped ahead */
440 lost = true;
441 }
442
443 if (lost)
444 perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
445
446 /* finally tell HW where we want to start reading from */
447 writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
448
449 cur = buf->cur;
450 offset = buf->offset;
451 barrier = barrier_pkt;
452
453 for (i = 0; i < to_read; i += 4) {
454 buf_ptr = buf->data_pages[cur] + offset;
455 read_data = readl_relaxed(drvdata->base +
456 ETB_RAM_READ_DATA_REG);
457 if (lost && *barrier) {
458 read_data = *barrier;
459 barrier++;
460 }
461
462 *(u32 *)buf_ptr = read_data;
463 buf_ptr += 4;
464
465 offset += 4;
466 if (offset >= PAGE_SIZE) {
467 offset = 0;
468 cur++;
469 /* wrap around at the end of the buffer */
470 cur &= buf->nr_pages - 1;
471 }
472 }
473
474 /* reset ETB buffer for next run */
475 writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
476 writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
477
478 /*
479 * In snapshot mode all we have to do is communicate to
480 * perf_aux_output_end() the address of the current head. In full
481 * trace mode the same function expects a size to move rb->aux_head
482 * forward.
483 */
484 if (buf->snapshot)
485 local_set(&buf->data_size, (cur * PAGE_SIZE) + offset);
486 else
487 local_add(to_read, &buf->data_size);
488
489 etb_enable_hw(drvdata);
490 CS_LOCK(drvdata->base);
491}
492
493static const struct coresight_ops_sink etb_sink_ops = {
494 .enable = etb_enable,
495 .disable = etb_disable,
496 .alloc_buffer = etb_alloc_buffer,
497 .free_buffer = etb_free_buffer,
498 .set_buffer = etb_set_buffer,
499 .reset_buffer = etb_reset_buffer,
500 .update_buffer = etb_update_buffer,
501};
502
503static const struct coresight_ops etb_cs_ops = {
504 .sink_ops = &etb_sink_ops,
505};
506
507static void etb_dump(struct etb_drvdata *drvdata)
508{
509 unsigned long flags;
510
511 spin_lock_irqsave(&drvdata->spinlock, flags);
512 if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
513 etb_disable_hw(drvdata);
514 etb_dump_hw(drvdata);
515 etb_enable_hw(drvdata);
516 }
517 spin_unlock_irqrestore(&drvdata->spinlock, flags);
518
519 dev_info(drvdata->dev, "ETB dumped\n");
520}
521
522static int etb_open(struct inode *inode, struct file *file)
523{
524 struct etb_drvdata *drvdata = container_of(file->private_data,
525 struct etb_drvdata, miscdev);
526
527 if (local_cmpxchg(&drvdata->reading, 0, 1))
528 return -EBUSY;
529
530 dev_dbg(drvdata->dev, "%s: successfully opened\n", __func__);
531 return 0;
532}
533
534static ssize_t etb_read(struct file *file, char __user *data,
535 size_t len, loff_t *ppos)
536{
537 u32 depth;
538 struct etb_drvdata *drvdata = container_of(file->private_data,
539 struct etb_drvdata, miscdev);
540
541 etb_dump(drvdata);
542
543 depth = drvdata->buffer_depth;
544 if (*ppos + len > depth * 4)
545 len = depth * 4 - *ppos;
546
547 if (copy_to_user(data, drvdata->buf + *ppos, len)) {
548 dev_dbg(drvdata->dev, "%s: copy_to_user failed\n", __func__);
549 return -EFAULT;
550 }
551
552 *ppos += len;
553
554 dev_dbg(drvdata->dev, "%s: %zu bytes copied, %d bytes left\n",
555 __func__, len, (int)(depth * 4 - *ppos));
556 return len;
557}
558
559static int etb_release(struct inode *inode, struct file *file)
560{
561 struct etb_drvdata *drvdata = container_of(file->private_data,
562 struct etb_drvdata, miscdev);
563 local_set(&drvdata->reading, 0);
564
565 dev_dbg(drvdata->dev, "%s: released\n", __func__);
566 return 0;
567}
568
569static const struct file_operations etb_fops = {
570 .owner = THIS_MODULE,
571 .open = etb_open,
572 .read = etb_read,
573 .release = etb_release,
574 .llseek = no_llseek,
575};
576
577#define coresight_etb10_reg(name, offset) \
578 coresight_simple_reg32(struct etb_drvdata, name, offset)
579
580coresight_etb10_reg(rdp, ETB_RAM_DEPTH_REG);
581coresight_etb10_reg(sts, ETB_STATUS_REG);
582coresight_etb10_reg(rrp, ETB_RAM_READ_POINTER);
583coresight_etb10_reg(rwp, ETB_RAM_WRITE_POINTER);
584coresight_etb10_reg(trg, ETB_TRG);
585coresight_etb10_reg(ctl, ETB_CTL_REG);
586coresight_etb10_reg(ffsr, ETB_FFSR);
587coresight_etb10_reg(ffcr, ETB_FFCR);
588
589static struct attribute *coresight_etb_mgmt_attrs[] = {
590 &dev_attr_rdp.attr,
591 &dev_attr_sts.attr,
592 &dev_attr_rrp.attr,
593 &dev_attr_rwp.attr,
594 &dev_attr_trg.attr,
595 &dev_attr_ctl.attr,
596 &dev_attr_ffsr.attr,
597 &dev_attr_ffcr.attr,
598 NULL,
599};
600
601static ssize_t trigger_cntr_show(struct device *dev,
602 struct device_attribute *attr, char *buf)
603{
604 struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
605 unsigned long val = drvdata->trigger_cntr;
606
607 return sprintf(buf, "%#lx\n", val);
608}
609
610static ssize_t trigger_cntr_store(struct device *dev,
611 struct device_attribute *attr,
612 const char *buf, size_t size)
613{
614 int ret;
615 unsigned long val;
616 struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
617
618 ret = kstrtoul(buf, 16, &val);
619 if (ret)
620 return ret;
621
622 drvdata->trigger_cntr = val;
623 return size;
624}
625static DEVICE_ATTR_RW(trigger_cntr);
626
627static struct attribute *coresight_etb_attrs[] = {
628 &dev_attr_trigger_cntr.attr,
629 NULL,
630};
631
632static const struct attribute_group coresight_etb_group = {
633 .attrs = coresight_etb_attrs,
634};
635
636static const struct attribute_group coresight_etb_mgmt_group = {
637 .attrs = coresight_etb_mgmt_attrs,
638 .name = "mgmt",
639};
640
641const struct attribute_group *coresight_etb_groups[] = {
642 &coresight_etb_group,
643 &coresight_etb_mgmt_group,
644 NULL,
645};
646
647static int etb_probe(struct amba_device *adev, const struct amba_id *id)
648{
649 int ret;
650 void __iomem *base;
651 struct device *dev = &adev->dev;
652 struct coresight_platform_data *pdata = NULL;
653 struct etb_drvdata *drvdata;
654 struct resource *res = &adev->res;
655 struct coresight_desc desc = { 0 };
656 struct device_node *np = adev->dev.of_node;
657
658 if (np) {
659 pdata = of_get_coresight_platform_data(dev, np);
660 if (IS_ERR(pdata))
661 return PTR_ERR(pdata);
662 adev->dev.platform_data = pdata;
663 }
664
665 drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
666 if (!drvdata)
667 return -ENOMEM;
668
669 drvdata->dev = &adev->dev;
670 drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
671 if (!IS_ERR(drvdata->atclk)) {
672 ret = clk_prepare_enable(drvdata->atclk);
673 if (ret)
674 return ret;
675 }
676 dev_set_drvdata(dev, drvdata);
677
678 /* validity for the resource is already checked by the AMBA core */
679 base = devm_ioremap_resource(dev, res);
680 if (IS_ERR(base))
681 return PTR_ERR(base);
682
683 drvdata->base = base;
684
685 spin_lock_init(&drvdata->spinlock);
686
687 drvdata->buffer_depth = etb_get_buffer_depth(drvdata);
688 pm_runtime_put(&adev->dev);
689
690 if (drvdata->buffer_depth & 0x80000000)
691 return -EINVAL;
692
693 drvdata->buf = devm_kzalloc(dev,
694 drvdata->buffer_depth * 4, GFP_KERNEL);
695 if (!drvdata->buf)
696 return -ENOMEM;
697
698 desc.type = CORESIGHT_DEV_TYPE_SINK;
699 desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
700 desc.ops = &etb_cs_ops;
701 desc.pdata = pdata;
702 desc.dev = dev;
703 desc.groups = coresight_etb_groups;
704 drvdata->csdev = coresight_register(&desc);
705 if (IS_ERR(drvdata->csdev))
706 return PTR_ERR(drvdata->csdev);
707
708 drvdata->miscdev.name = pdata->name;
709 drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
710 drvdata->miscdev.fops = &etb_fops;
711 ret = misc_register(&drvdata->miscdev);
712 if (ret)
713 goto err_misc_register;
714
715 return 0;
716
717err_misc_register:
718 coresight_unregister(drvdata->csdev);
719 return ret;
720}
721
722#ifdef CONFIG_PM
723static int etb_runtime_suspend(struct device *dev)
724{
725 struct etb_drvdata *drvdata = dev_get_drvdata(dev);
726
727 if (drvdata && !IS_ERR(drvdata->atclk))
728 clk_disable_unprepare(drvdata->atclk);
729
730 return 0;
731}
732
733static int etb_runtime_resume(struct device *dev)
734{
735 struct etb_drvdata *drvdata = dev_get_drvdata(dev);
736
737 if (drvdata && !IS_ERR(drvdata->atclk))
738 clk_prepare_enable(drvdata->atclk);
739
740 return 0;
741}
742#endif
743
744static const struct dev_pm_ops etb_dev_pm_ops = {
745 SET_RUNTIME_PM_OPS(etb_runtime_suspend, etb_runtime_resume, NULL)
746};
747
748static const struct amba_id etb_ids[] = {
749 {
750 .id = 0x000bb907,
751 .mask = 0x000fffff,
752 },
753 { 0, 0},
754};
755
756static struct amba_driver etb_driver = {
757 .drv = {
758 .name = "coresight-etb10",
759 .owner = THIS_MODULE,
760 .pm = &etb_dev_pm_ops,
761 .suppress_bind_attrs = true,
762
763 },
764 .probe = etb_probe,
765 .id_table = etb_ids,
766};
767builtin_amba_driver(etb_driver);
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
66DEFINE_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 */
83struct 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
97static int etb_set_buffer(struct coresight_device *csdev,
98 struct perf_output_handle *handle);
99
100static inline unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata)
101{
102 return readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
103}
104
105static 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
133static int etb_enable_hw(struct etb_drvdata *drvdata)
134{
135 int rc = coresight_claim_device(drvdata->csdev);
136
137 if (rc)
138 return rc;
139
140 __etb_enable_hw(drvdata);
141 return 0;
142}
143
144static 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);
167out:
168 spin_unlock_irqrestore(&drvdata->spinlock, flags);
169 return ret;
170}
171
172static 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 struct cs_buffers *buf = etm_perf_sink_config(handle);
180
181 spin_lock_irqsave(&drvdata->spinlock, flags);
182
183 /* No need to continue if the component is already in used by sysFS. */
184 if (drvdata->mode == CS_MODE_SYSFS) {
185 ret = -EBUSY;
186 goto out;
187 }
188
189 /* Get a handle on the pid of the process to monitor */
190 pid = buf->pid;
191
192 if (drvdata->pid != -1 && drvdata->pid != pid) {
193 ret = -EBUSY;
194 goto out;
195 }
196
197 /*
198 * No HW configuration is needed if the sink is already in
199 * use for this session.
200 */
201 if (drvdata->pid == pid) {
202 atomic_inc(&csdev->refcnt);
203 goto out;
204 }
205
206 /*
207 * We don't have an internal state to clean up if we fail to setup
208 * the perf buffer. So we can perform the step before we turn the
209 * ETB on and leave without cleaning up.
210 */
211 ret = etb_set_buffer(csdev, handle);
212 if (ret)
213 goto out;
214
215 ret = etb_enable_hw(drvdata);
216 if (!ret) {
217 /* Associate with monitored process. */
218 drvdata->pid = pid;
219 drvdata->mode = CS_MODE_PERF;
220 atomic_inc(&csdev->refcnt);
221 }
222
223out:
224 spin_unlock_irqrestore(&drvdata->spinlock, flags);
225 return ret;
226}
227
228static int etb_enable(struct coresight_device *csdev, enum cs_mode mode,
229 void *data)
230{
231 int ret;
232
233 switch (mode) {
234 case CS_MODE_SYSFS:
235 ret = etb_enable_sysfs(csdev);
236 break;
237 case CS_MODE_PERF:
238 ret = etb_enable_perf(csdev, data);
239 break;
240 default:
241 ret = -EINVAL;
242 break;
243 }
244
245 if (ret)
246 return ret;
247
248 dev_dbg(&csdev->dev, "ETB enabled\n");
249 return 0;
250}
251
252static void __etb_disable_hw(struct etb_drvdata *drvdata)
253{
254 u32 ffcr;
255 struct device *dev = &drvdata->csdev->dev;
256 struct csdev_access *csa = &drvdata->csdev->access;
257
258 CS_UNLOCK(drvdata->base);
259
260 ffcr = readl_relaxed(drvdata->base + ETB_FFCR);
261 /* stop formatter when a stop has completed */
262 ffcr |= ETB_FFCR_STOP_FI;
263 writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
264 /* manually generate a flush of the system */
265 ffcr |= ETB_FFCR_FON_MAN;
266 writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
267
268 if (coresight_timeout(csa, ETB_FFCR, ETB_FFCR_BIT, 0)) {
269 dev_err(dev,
270 "timeout while waiting for completion of Manual Flush\n");
271 }
272
273 /* disable trace capture */
274 writel_relaxed(0x0, drvdata->base + ETB_CTL_REG);
275
276 if (coresight_timeout(csa, ETB_FFSR, ETB_FFSR_BIT, 1)) {
277 dev_err(dev,
278 "timeout while waiting for Formatter to Stop\n");
279 }
280
281 CS_LOCK(drvdata->base);
282}
283
284static void etb_dump_hw(struct etb_drvdata *drvdata)
285{
286 bool lost = false;
287 int i;
288 u8 *buf_ptr;
289 u32 read_data, depth;
290 u32 read_ptr, write_ptr;
291 u32 frame_off, frame_endoff;
292 struct device *dev = &drvdata->csdev->dev;
293
294 CS_UNLOCK(drvdata->base);
295
296 read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
297 write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
298
299 frame_off = write_ptr % ETB_FRAME_SIZE_WORDS;
300 frame_endoff = ETB_FRAME_SIZE_WORDS - frame_off;
301 if (frame_off) {
302 dev_err(dev,
303 "write_ptr: %lu not aligned to formatter frame size\n",
304 (unsigned long)write_ptr);
305 dev_err(dev, "frameoff: %lu, frame_endoff: %lu\n",
306 (unsigned long)frame_off, (unsigned long)frame_endoff);
307 write_ptr += frame_endoff;
308 }
309
310 if ((readl_relaxed(drvdata->base + ETB_STATUS_REG)
311 & ETB_STATUS_RAM_FULL) == 0) {
312 writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
313 } else {
314 writel_relaxed(write_ptr, drvdata->base + ETB_RAM_READ_POINTER);
315 lost = true;
316 }
317
318 depth = drvdata->buffer_depth;
319 buf_ptr = drvdata->buf;
320 for (i = 0; i < depth; i++) {
321 read_data = readl_relaxed(drvdata->base +
322 ETB_RAM_READ_DATA_REG);
323 *(u32 *)buf_ptr = read_data;
324 buf_ptr += 4;
325 }
326
327 if (lost)
328 coresight_insert_barrier_packet(drvdata->buf);
329
330 if (frame_off) {
331 buf_ptr -= (frame_endoff * 4);
332 for (i = 0; i < frame_endoff; i++) {
333 *buf_ptr++ = 0x0;
334 *buf_ptr++ = 0x0;
335 *buf_ptr++ = 0x0;
336 *buf_ptr++ = 0x0;
337 }
338 }
339
340 writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
341
342 CS_LOCK(drvdata->base);
343}
344
345static void etb_disable_hw(struct etb_drvdata *drvdata)
346{
347 __etb_disable_hw(drvdata);
348 etb_dump_hw(drvdata);
349 coresight_disclaim_device(drvdata->csdev);
350}
351
352static int etb_disable(struct coresight_device *csdev)
353{
354 struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
355 unsigned long flags;
356
357 spin_lock_irqsave(&drvdata->spinlock, flags);
358
359 if (atomic_dec_return(&csdev->refcnt)) {
360 spin_unlock_irqrestore(&drvdata->spinlock, flags);
361 return -EBUSY;
362 }
363
364 /* Complain if we (somehow) got out of sync */
365 WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
366 etb_disable_hw(drvdata);
367 /* Dissociate from monitored process. */
368 drvdata->pid = -1;
369 drvdata->mode = CS_MODE_DISABLED;
370 spin_unlock_irqrestore(&drvdata->spinlock, flags);
371
372 dev_dbg(&csdev->dev, "ETB disabled\n");
373 return 0;
374}
375
376static void *etb_alloc_buffer(struct coresight_device *csdev,
377 struct perf_event *event, void **pages,
378 int nr_pages, bool overwrite)
379{
380 int node;
381 struct cs_buffers *buf;
382
383 node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);
384
385 buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
386 if (!buf)
387 return NULL;
388
389 buf->pid = task_pid_nr(event->owner);
390 buf->snapshot = overwrite;
391 buf->nr_pages = nr_pages;
392 buf->data_pages = pages;
393
394 return buf;
395}
396
397static void etb_free_buffer(void *config)
398{
399 struct cs_buffers *buf = config;
400
401 kfree(buf);
402}
403
404static int etb_set_buffer(struct coresight_device *csdev,
405 struct perf_output_handle *handle)
406{
407 int ret = 0;
408 unsigned long head;
409 struct cs_buffers *buf = etm_perf_sink_config(handle);
410
411 if (!buf)
412 return -EINVAL;
413
414 /* wrap head around to the amount of space we have */
415 head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1);
416
417 /* find the page to write to */
418 buf->cur = head / PAGE_SIZE;
419
420 /* and offset within that page */
421 buf->offset = head % PAGE_SIZE;
422
423 local_set(&buf->data_size, 0);
424
425 return ret;
426}
427
428static unsigned long etb_update_buffer(struct coresight_device *csdev,
429 struct perf_output_handle *handle,
430 void *sink_config)
431{
432 bool lost = false;
433 int i, cur;
434 u8 *buf_ptr;
435 const u32 *barrier;
436 u32 read_ptr, write_ptr, capacity;
437 u32 status, read_data;
438 unsigned long offset, to_read = 0, flags;
439 struct cs_buffers *buf = sink_config;
440 struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
441
442 if (!buf)
443 return 0;
444
445 capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS;
446
447 spin_lock_irqsave(&drvdata->spinlock, flags);
448
449 /* Don't do anything if another tracer is using this sink */
450 if (atomic_read(&csdev->refcnt) != 1)
451 goto out;
452
453 __etb_disable_hw(drvdata);
454 CS_UNLOCK(drvdata->base);
455
456 /* unit is in words, not bytes */
457 read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
458 write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
459
460 /*
461 * Entries should be aligned to the frame size. If they are not
462 * go back to the last alignment point to give decoding tools a
463 * chance to fix things.
464 */
465 if (write_ptr % ETB_FRAME_SIZE_WORDS) {
466 dev_err(&csdev->dev,
467 "write_ptr: %lu not aligned to formatter frame size\n",
468 (unsigned long)write_ptr);
469
470 write_ptr &= ~(ETB_FRAME_SIZE_WORDS - 1);
471 lost = true;
472 }
473
474 /*
475 * Get a hold of the status register and see if a wrap around
476 * has occurred. If so adjust things accordingly. Otherwise
477 * start at the beginning and go until the write pointer has
478 * been reached.
479 */
480 status = readl_relaxed(drvdata->base + ETB_STATUS_REG);
481 if (status & ETB_STATUS_RAM_FULL) {
482 lost = true;
483 to_read = capacity;
484 read_ptr = write_ptr;
485 } else {
486 to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->buffer_depth);
487 to_read *= ETB_FRAME_SIZE_WORDS;
488 }
489
490 /*
491 * Make sure we don't overwrite data that hasn't been consumed yet.
492 * It is entirely possible that the HW buffer has more data than the
493 * ring buffer can currently handle. If so adjust the start address
494 * to take only the last traces.
495 *
496 * In snapshot mode we are looking to get the latest traces only and as
497 * such, we don't care about not overwriting data that hasn't been
498 * processed by user space.
499 */
500 if (!buf->snapshot && to_read > handle->size) {
501 u32 mask = ~(ETB_FRAME_SIZE_WORDS - 1);
502
503 /* The new read pointer must be frame size aligned */
504 to_read = handle->size & mask;
505 /*
506 * Move the RAM read pointer up, keeping in mind that
507 * everything is in frame size units.
508 */
509 read_ptr = (write_ptr + drvdata->buffer_depth) -
510 to_read / ETB_FRAME_SIZE_WORDS;
511 /* Wrap around if need be*/
512 if (read_ptr > (drvdata->buffer_depth - 1))
513 read_ptr -= drvdata->buffer_depth;
514 /* let the decoder know we've skipped ahead */
515 lost = true;
516 }
517
518 /*
519 * Don't set the TRUNCATED flag in snapshot mode because 1) the
520 * captured buffer is expected to be truncated and 2) a full buffer
521 * prevents the event from being re-enabled by the perf core,
522 * resulting in stale data being send to user space.
523 */
524 if (!buf->snapshot && lost)
525 perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
526
527 /* finally tell HW where we want to start reading from */
528 writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
529
530 cur = buf->cur;
531 offset = buf->offset;
532 barrier = coresight_barrier_pkt;
533
534 for (i = 0; i < to_read; i += 4) {
535 buf_ptr = buf->data_pages[cur] + offset;
536 read_data = readl_relaxed(drvdata->base +
537 ETB_RAM_READ_DATA_REG);
538 if (lost && i < CORESIGHT_BARRIER_PKT_SIZE) {
539 read_data = *barrier;
540 barrier++;
541 }
542
543 *(u32 *)buf_ptr = read_data;
544 buf_ptr += 4;
545
546 offset += 4;
547 if (offset >= PAGE_SIZE) {
548 offset = 0;
549 cur++;
550 /* wrap around at the end of the buffer */
551 cur &= buf->nr_pages - 1;
552 }
553 }
554
555 /* reset ETB buffer for next run */
556 writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
557 writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
558
559 /*
560 * In snapshot mode we simply increment the head by the number of byte
561 * that were written. User space will figure out how many bytes to get
562 * from the AUX buffer based on the position of the head.
563 */
564 if (buf->snapshot)
565 handle->head += to_read;
566
567 __etb_enable_hw(drvdata);
568 CS_LOCK(drvdata->base);
569out:
570 spin_unlock_irqrestore(&drvdata->spinlock, flags);
571
572 return to_read;
573}
574
575static const struct coresight_ops_sink etb_sink_ops = {
576 .enable = etb_enable,
577 .disable = etb_disable,
578 .alloc_buffer = etb_alloc_buffer,
579 .free_buffer = etb_free_buffer,
580 .update_buffer = etb_update_buffer,
581};
582
583static const struct coresight_ops etb_cs_ops = {
584 .sink_ops = &etb_sink_ops,
585};
586
587static void etb_dump(struct etb_drvdata *drvdata)
588{
589 unsigned long flags;
590
591 spin_lock_irqsave(&drvdata->spinlock, flags);
592 if (drvdata->mode == CS_MODE_SYSFS) {
593 __etb_disable_hw(drvdata);
594 etb_dump_hw(drvdata);
595 __etb_enable_hw(drvdata);
596 }
597 spin_unlock_irqrestore(&drvdata->spinlock, flags);
598
599 dev_dbg(&drvdata->csdev->dev, "ETB dumped\n");
600}
601
602static int etb_open(struct inode *inode, struct file *file)
603{
604 struct etb_drvdata *drvdata = container_of(file->private_data,
605 struct etb_drvdata, miscdev);
606
607 if (local_cmpxchg(&drvdata->reading, 0, 1))
608 return -EBUSY;
609
610 dev_dbg(&drvdata->csdev->dev, "%s: successfully opened\n", __func__);
611 return 0;
612}
613
614static ssize_t etb_read(struct file *file, char __user *data,
615 size_t len, loff_t *ppos)
616{
617 u32 depth;
618 struct etb_drvdata *drvdata = container_of(file->private_data,
619 struct etb_drvdata, miscdev);
620 struct device *dev = &drvdata->csdev->dev;
621
622 etb_dump(drvdata);
623
624 depth = drvdata->buffer_depth;
625 if (*ppos + len > depth * 4)
626 len = depth * 4 - *ppos;
627
628 if (copy_to_user(data, drvdata->buf + *ppos, len)) {
629 dev_dbg(dev,
630 "%s: copy_to_user failed\n", __func__);
631 return -EFAULT;
632 }
633
634 *ppos += len;
635
636 dev_dbg(dev, "%s: %zu bytes copied, %d bytes left\n",
637 __func__, len, (int)(depth * 4 - *ppos));
638 return len;
639}
640
641static int etb_release(struct inode *inode, struct file *file)
642{
643 struct etb_drvdata *drvdata = container_of(file->private_data,
644 struct etb_drvdata, miscdev);
645 local_set(&drvdata->reading, 0);
646
647 dev_dbg(&drvdata->csdev->dev, "%s: released\n", __func__);
648 return 0;
649}
650
651static const struct file_operations etb_fops = {
652 .owner = THIS_MODULE,
653 .open = etb_open,
654 .read = etb_read,
655 .release = etb_release,
656 .llseek = no_llseek,
657};
658
659static struct attribute *coresight_etb_mgmt_attrs[] = {
660 coresight_simple_reg32(rdp, ETB_RAM_DEPTH_REG),
661 coresight_simple_reg32(sts, ETB_STATUS_REG),
662 coresight_simple_reg32(rrp, ETB_RAM_READ_POINTER),
663 coresight_simple_reg32(rwp, ETB_RAM_WRITE_POINTER),
664 coresight_simple_reg32(trg, ETB_TRG),
665 coresight_simple_reg32(ctl, ETB_CTL_REG),
666 coresight_simple_reg32(ffsr, ETB_FFSR),
667 coresight_simple_reg32(ffcr, ETB_FFCR),
668 NULL,
669};
670
671static ssize_t trigger_cntr_show(struct device *dev,
672 struct device_attribute *attr, char *buf)
673{
674 struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
675 unsigned long val = drvdata->trigger_cntr;
676
677 return sprintf(buf, "%#lx\n", val);
678}
679
680static ssize_t trigger_cntr_store(struct device *dev,
681 struct device_attribute *attr,
682 const char *buf, size_t size)
683{
684 int ret;
685 unsigned long val;
686 struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
687
688 ret = kstrtoul(buf, 16, &val);
689 if (ret)
690 return ret;
691
692 drvdata->trigger_cntr = val;
693 return size;
694}
695static DEVICE_ATTR_RW(trigger_cntr);
696
697static struct attribute *coresight_etb_attrs[] = {
698 &dev_attr_trigger_cntr.attr,
699 NULL,
700};
701
702static const struct attribute_group coresight_etb_group = {
703 .attrs = coresight_etb_attrs,
704};
705
706static const struct attribute_group coresight_etb_mgmt_group = {
707 .attrs = coresight_etb_mgmt_attrs,
708 .name = "mgmt",
709};
710
711static const struct attribute_group *coresight_etb_groups[] = {
712 &coresight_etb_group,
713 &coresight_etb_mgmt_group,
714 NULL,
715};
716
717static int etb_probe(struct amba_device *adev, const struct amba_id *id)
718{
719 int ret;
720 void __iomem *base;
721 struct device *dev = &adev->dev;
722 struct coresight_platform_data *pdata = NULL;
723 struct etb_drvdata *drvdata;
724 struct resource *res = &adev->res;
725 struct coresight_desc desc = { 0 };
726
727 desc.name = coresight_alloc_device_name(&etb_devs, dev);
728 if (!desc.name)
729 return -ENOMEM;
730
731 drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
732 if (!drvdata)
733 return -ENOMEM;
734
735 drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
736 if (!IS_ERR(drvdata->atclk)) {
737 ret = clk_prepare_enable(drvdata->atclk);
738 if (ret)
739 return ret;
740 }
741 dev_set_drvdata(dev, drvdata);
742
743 /* validity for the resource is already checked by the AMBA core */
744 base = devm_ioremap_resource(dev, res);
745 if (IS_ERR(base))
746 return PTR_ERR(base);
747
748 drvdata->base = base;
749 desc.access = CSDEV_ACCESS_IOMEM(base);
750
751 spin_lock_init(&drvdata->spinlock);
752
753 drvdata->buffer_depth = etb_get_buffer_depth(drvdata);
754
755 if (drvdata->buffer_depth & 0x80000000)
756 return -EINVAL;
757
758 drvdata->buf = devm_kcalloc(dev,
759 drvdata->buffer_depth, 4, GFP_KERNEL);
760 if (!drvdata->buf)
761 return -ENOMEM;
762
763 /* This device is not associated with a session */
764 drvdata->pid = -1;
765
766 pdata = coresight_get_platform_data(dev);
767 if (IS_ERR(pdata))
768 return PTR_ERR(pdata);
769 adev->dev.platform_data = pdata;
770
771 desc.type = CORESIGHT_DEV_TYPE_SINK;
772 desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
773 desc.ops = &etb_cs_ops;
774 desc.pdata = pdata;
775 desc.dev = dev;
776 desc.groups = coresight_etb_groups;
777 drvdata->csdev = coresight_register(&desc);
778 if (IS_ERR(drvdata->csdev))
779 return PTR_ERR(drvdata->csdev);
780
781 drvdata->miscdev.name = desc.name;
782 drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
783 drvdata->miscdev.fops = &etb_fops;
784 ret = misc_register(&drvdata->miscdev);
785 if (ret)
786 goto err_misc_register;
787
788 pm_runtime_put(&adev->dev);
789 return 0;
790
791err_misc_register:
792 coresight_unregister(drvdata->csdev);
793 return ret;
794}
795
796static void etb_remove(struct amba_device *adev)
797{
798 struct etb_drvdata *drvdata = dev_get_drvdata(&adev->dev);
799
800 /*
801 * Since misc_open() holds a refcount on the f_ops, which is
802 * etb fops in this case, device is there until last file
803 * handler to this device is closed.
804 */
805 misc_deregister(&drvdata->miscdev);
806 coresight_unregister(drvdata->csdev);
807}
808
809#ifdef CONFIG_PM
810static int etb_runtime_suspend(struct device *dev)
811{
812 struct etb_drvdata *drvdata = dev_get_drvdata(dev);
813
814 if (drvdata && !IS_ERR(drvdata->atclk))
815 clk_disable_unprepare(drvdata->atclk);
816
817 return 0;
818}
819
820static int etb_runtime_resume(struct device *dev)
821{
822 struct etb_drvdata *drvdata = dev_get_drvdata(dev);
823
824 if (drvdata && !IS_ERR(drvdata->atclk))
825 clk_prepare_enable(drvdata->atclk);
826
827 return 0;
828}
829#endif
830
831static const struct dev_pm_ops etb_dev_pm_ops = {
832 SET_RUNTIME_PM_OPS(etb_runtime_suspend, etb_runtime_resume, NULL)
833};
834
835static const struct amba_id etb_ids[] = {
836 {
837 .id = 0x000bb907,
838 .mask = 0x000fffff,
839 },
840 { 0, 0},
841};
842
843MODULE_DEVICE_TABLE(amba, etb_ids);
844
845static struct amba_driver etb_driver = {
846 .drv = {
847 .name = "coresight-etb10",
848 .owner = THIS_MODULE,
849 .pm = &etb_dev_pm_ops,
850 .suppress_bind_attrs = true,
851
852 },
853 .probe = etb_probe,
854 .remove = etb_remove,
855 .id_table = etb_ids,
856};
857
858module_amba_driver(etb_driver);
859
860MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
861MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
862MODULE_DESCRIPTION("Arm CoreSight Embedded Trace Buffer driver");
863MODULE_LICENSE("GPL v2");