1 /* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
3 * Description: CoreSight Embedded Trace Buffer driver
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.
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.
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>
21 #include <linux/err.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>
34 #include <linux/perf_event.h>
36 #include <asm/local.h>
38 #include "coresight-priv.h"
40 #define ETB_RAM_DEPTH_REG 0x004
41 #define ETB_STATUS_REG 0x00c
42 #define ETB_RAM_READ_DATA_REG 0x010
43 #define ETB_RAM_READ_POINTER 0x014
44 #define ETB_RAM_WRITE_POINTER 0x018
46 #define ETB_CTL_REG 0x020
47 #define ETB_RWD_REG 0x024
48 #define ETB_FFSR 0x300
49 #define ETB_FFCR 0x304
50 #define ETB_ITMISCOP0 0xee0
51 #define ETB_ITTRFLINACK 0xee4
52 #define ETB_ITTRFLIN 0xee8
53 #define ETB_ITATBDATA0 0xeeC
54 #define ETB_ITATBCTR2 0xef0
55 #define ETB_ITATBCTR1 0xef4
56 #define ETB_ITATBCTR0 0xef8
58 /* register description */
60 #define ETB_STATUS_RAM_FULL BIT(0)
62 #define ETB_CTL_CAPT_EN BIT(0)
64 #define ETB_FFCR_EN_FTC BIT(0)
65 #define ETB_FFCR_FON_MAN BIT(6)
66 #define ETB_FFCR_STOP_FI BIT(12)
67 #define ETB_FFCR_STOP_TRIGGER BIT(13)
69 #define ETB_FFCR_BIT 6
70 #define ETB_FFSR_BIT 1
71 #define ETB_FRAME_SIZE_WORDS 4
74 * struct etb_drvdata - specifics associated to an ETB component
75 * @base: memory mapped base address for this component.
76 * @dev: the device entity associated to this component.
77 * @atclk: optional clock for the core parts of the ETB.
78 * @csdev: component vitals needed by the framework.
79 * @miscdev: specifics to handle "/dev/xyz.etb" entry.
80 * @spinlock: only one at a time pls.
81 * @reading: synchronise user space access to etb buffer.
82 * @mode: this ETB is being used.
83 * @buf: area of memory where ETB buffer content gets sent.
84 * @buffer_depth: size of @buf.
85 * @trigger_cntr: amount of words to store after a trigger.
91 struct coresight_device
*csdev
;
92 struct miscdevice miscdev
;
101 static unsigned int etb_get_buffer_depth(struct etb_drvdata
*drvdata
)
105 pm_runtime_get_sync(drvdata
->dev
);
107 /* RO registers don't need locking */
108 depth
= readl_relaxed(drvdata
->base
+ ETB_RAM_DEPTH_REG
);
110 pm_runtime_put(drvdata
->dev
);
114 static void etb_enable_hw(struct etb_drvdata
*drvdata
)
119 CS_UNLOCK(drvdata
->base
);
121 depth
= drvdata
->buffer_depth
;
122 /* reset write RAM pointer address */
123 writel_relaxed(0x0, drvdata
->base
+ ETB_RAM_WRITE_POINTER
);
124 /* clear entire RAM buffer */
125 for (i
= 0; i
< depth
; i
++)
126 writel_relaxed(0x0, drvdata
->base
+ ETB_RWD_REG
);
128 /* reset write RAM pointer address */
129 writel_relaxed(0x0, drvdata
->base
+ ETB_RAM_WRITE_POINTER
);
130 /* reset read RAM pointer address */
131 writel_relaxed(0x0, drvdata
->base
+ ETB_RAM_READ_POINTER
);
133 writel_relaxed(drvdata
->trigger_cntr
, drvdata
->base
+ ETB_TRG
);
134 writel_relaxed(ETB_FFCR_EN_FTC
| ETB_FFCR_STOP_TRIGGER
,
135 drvdata
->base
+ ETB_FFCR
);
136 /* ETB trace capture enable */
137 writel_relaxed(ETB_CTL_CAPT_EN
, drvdata
->base
+ ETB_CTL_REG
);
139 CS_LOCK(drvdata
->base
);
142 static int etb_enable(struct coresight_device
*csdev
, u32 mode
)
146 struct etb_drvdata
*drvdata
= dev_get_drvdata(csdev
->dev
.parent
);
148 val
= local_cmpxchg(&drvdata
->mode
,
149 CS_MODE_DISABLED
, mode
);
151 * When accessing from Perf, a HW buffer can be handled
152 * by a single trace entity. In sysFS mode many tracers
153 * can be logging to the same HW buffer.
155 if (val
== CS_MODE_PERF
)
158 /* Nothing to do, the tracer is already enabled. */
159 if (val
== CS_MODE_SYSFS
)
162 spin_lock_irqsave(&drvdata
->spinlock
, flags
);
163 etb_enable_hw(drvdata
);
164 spin_unlock_irqrestore(&drvdata
->spinlock
, flags
);
167 dev_info(drvdata
->dev
, "ETB enabled\n");
171 static void etb_disable_hw(struct etb_drvdata
*drvdata
)
175 CS_UNLOCK(drvdata
->base
);
177 ffcr
= readl_relaxed(drvdata
->base
+ ETB_FFCR
);
178 /* stop formatter when a stop has completed */
179 ffcr
|= ETB_FFCR_STOP_FI
;
180 writel_relaxed(ffcr
, drvdata
->base
+ ETB_FFCR
);
181 /* manually generate a flush of the system */
182 ffcr
|= ETB_FFCR_FON_MAN
;
183 writel_relaxed(ffcr
, drvdata
->base
+ ETB_FFCR
);
185 if (coresight_timeout(drvdata
->base
, ETB_FFCR
, ETB_FFCR_BIT
, 0)) {
186 dev_err(drvdata
->dev
,
187 "timeout while waiting for completion of Manual Flush\n");
190 /* disable trace capture */
191 writel_relaxed(0x0, drvdata
->base
+ ETB_CTL_REG
);
193 if (coresight_timeout(drvdata
->base
, ETB_FFSR
, ETB_FFSR_BIT
, 1)) {
194 dev_err(drvdata
->dev
,
195 "timeout while waiting for Formatter to Stop\n");
198 CS_LOCK(drvdata
->base
);
201 static void etb_dump_hw(struct etb_drvdata
*drvdata
)
207 u32 read_data
, depth
;
208 u32 read_ptr
, write_ptr
;
209 u32 frame_off
, frame_endoff
;
211 CS_UNLOCK(drvdata
->base
);
213 read_ptr
= readl_relaxed(drvdata
->base
+ ETB_RAM_READ_POINTER
);
214 write_ptr
= readl_relaxed(drvdata
->base
+ ETB_RAM_WRITE_POINTER
);
216 frame_off
= write_ptr
% ETB_FRAME_SIZE_WORDS
;
217 frame_endoff
= ETB_FRAME_SIZE_WORDS
- frame_off
;
219 dev_err(drvdata
->dev
,
220 "write_ptr: %lu not aligned to formatter frame size\n",
221 (unsigned long)write_ptr
);
222 dev_err(drvdata
->dev
, "frameoff: %lu, frame_endoff: %lu\n",
223 (unsigned long)frame_off
, (unsigned long)frame_endoff
);
224 write_ptr
+= frame_endoff
;
227 if ((readl_relaxed(drvdata
->base
+ ETB_STATUS_REG
)
228 & ETB_STATUS_RAM_FULL
) == 0) {
229 writel_relaxed(0x0, drvdata
->base
+ ETB_RAM_READ_POINTER
);
231 writel_relaxed(write_ptr
, drvdata
->base
+ ETB_RAM_READ_POINTER
);
235 depth
= drvdata
->buffer_depth
;
236 buf_ptr
= drvdata
->buf
;
237 barrier
= barrier_pkt
;
238 for (i
= 0; i
< depth
; i
++) {
239 read_data
= readl_relaxed(drvdata
->base
+
240 ETB_RAM_READ_DATA_REG
);
241 if (lost
&& *barrier
) {
242 read_data
= *barrier
;
246 *(u32
*)buf_ptr
= read_data
;
251 buf_ptr
-= (frame_endoff
* 4);
252 for (i
= 0; i
< frame_endoff
; i
++) {
260 writel_relaxed(read_ptr
, drvdata
->base
+ ETB_RAM_READ_POINTER
);
262 CS_LOCK(drvdata
->base
);
265 static void etb_disable(struct coresight_device
*csdev
)
267 struct etb_drvdata
*drvdata
= dev_get_drvdata(csdev
->dev
.parent
);
270 spin_lock_irqsave(&drvdata
->spinlock
, flags
);
271 etb_disable_hw(drvdata
);
272 etb_dump_hw(drvdata
);
273 spin_unlock_irqrestore(&drvdata
->spinlock
, flags
);
275 local_set(&drvdata
->mode
, CS_MODE_DISABLED
);
277 dev_info(drvdata
->dev
, "ETB disabled\n");
280 static void *etb_alloc_buffer(struct coresight_device
*csdev
, int cpu
,
281 void **pages
, int nr_pages
, bool overwrite
)
284 struct cs_buffers
*buf
;
287 cpu
= smp_processor_id();
288 node
= cpu_to_node(cpu
);
290 buf
= kzalloc_node(sizeof(struct cs_buffers
), GFP_KERNEL
, node
);
294 buf
->snapshot
= overwrite
;
295 buf
->nr_pages
= nr_pages
;
296 buf
->data_pages
= pages
;
301 static void etb_free_buffer(void *config
)
303 struct cs_buffers
*buf
= config
;
308 static int etb_set_buffer(struct coresight_device
*csdev
,
309 struct perf_output_handle
*handle
,
314 struct cs_buffers
*buf
= sink_config
;
316 /* wrap head around to the amount of space we have */
317 head
= handle
->head
& ((buf
->nr_pages
<< PAGE_SHIFT
) - 1);
319 /* find the page to write to */
320 buf
->cur
= head
/ PAGE_SIZE
;
322 /* and offset within that page */
323 buf
->offset
= head
% PAGE_SIZE
;
325 local_set(&buf
->data_size
, 0);
330 static unsigned long etb_reset_buffer(struct coresight_device
*csdev
,
331 struct perf_output_handle
*handle
,
334 unsigned long size
= 0;
335 struct cs_buffers
*buf
= sink_config
;
339 * In snapshot mode ->data_size holds the new address of the
340 * ring buffer's head. The size itself is the whole address
341 * range since we want the latest information.
344 handle
->head
= local_xchg(&buf
->data_size
,
345 buf
->nr_pages
<< PAGE_SHIFT
);
348 * Tell the tracer PMU how much we got in this run and if
349 * something went wrong along the way. Nobody else can use
350 * this cs_buffers instance until we are done. As such
351 * resetting parameters here and squaring off with the ring
352 * buffer API in the tracer PMU is fine.
354 size
= local_xchg(&buf
->data_size
, 0);
360 static void etb_update_buffer(struct coresight_device
*csdev
,
361 struct perf_output_handle
*handle
,
368 u32 read_ptr
, write_ptr
, capacity
;
369 u32 status
, read_data
, to_read
;
370 unsigned long offset
;
371 struct cs_buffers
*buf
= sink_config
;
372 struct etb_drvdata
*drvdata
= dev_get_drvdata(csdev
->dev
.parent
);
377 capacity
= drvdata
->buffer_depth
* ETB_FRAME_SIZE_WORDS
;
379 etb_disable_hw(drvdata
);
380 CS_UNLOCK(drvdata
->base
);
382 /* unit is in words, not bytes */
383 read_ptr
= readl_relaxed(drvdata
->base
+ ETB_RAM_READ_POINTER
);
384 write_ptr
= readl_relaxed(drvdata
->base
+ ETB_RAM_WRITE_POINTER
);
387 * Entries should be aligned to the frame size. If they are not
388 * go back to the last alignment point to give decoding tools a
389 * chance to fix things.
391 if (write_ptr
% ETB_FRAME_SIZE_WORDS
) {
392 dev_err(drvdata
->dev
,
393 "write_ptr: %lu not aligned to formatter frame size\n",
394 (unsigned long)write_ptr
);
396 write_ptr
&= ~(ETB_FRAME_SIZE_WORDS
- 1);
401 * Get a hold of the status register and see if a wrap around
402 * has occurred. If so adjust things accordingly. Otherwise
403 * start at the beginning and go until the write pointer has
406 status
= readl_relaxed(drvdata
->base
+ ETB_STATUS_REG
);
407 if (status
& ETB_STATUS_RAM_FULL
) {
410 read_ptr
= write_ptr
;
412 to_read
= CIRC_CNT(write_ptr
, read_ptr
, drvdata
->buffer_depth
);
413 to_read
*= ETB_FRAME_SIZE_WORDS
;
417 * Make sure we don't overwrite data that hasn't been consumed yet.
418 * It is entirely possible that the HW buffer has more data than the
419 * ring buffer can currently handle. If so adjust the start address
420 * to take only the last traces.
422 * In snapshot mode we are looking to get the latest traces only and as
423 * such, we don't care about not overwriting data that hasn't been
424 * processed by user space.
426 if (!buf
->snapshot
&& to_read
> handle
->size
) {
427 u32 mask
= ~(ETB_FRAME_SIZE_WORDS
- 1);
429 /* The new read pointer must be frame size aligned */
430 to_read
= handle
->size
& mask
;
432 * Move the RAM read pointer up, keeping in mind that
433 * everything is in frame size units.
435 read_ptr
= (write_ptr
+ drvdata
->buffer_depth
) -
436 to_read
/ ETB_FRAME_SIZE_WORDS
;
437 /* Wrap around if need be*/
438 if (read_ptr
> (drvdata
->buffer_depth
- 1))
439 read_ptr
-= drvdata
->buffer_depth
;
440 /* let the decoder know we've skipped ahead */
445 perf_aux_output_flag(handle
, PERF_AUX_FLAG_TRUNCATED
);
447 /* finally tell HW where we want to start reading from */
448 writel_relaxed(read_ptr
, drvdata
->base
+ ETB_RAM_READ_POINTER
);
451 offset
= buf
->offset
;
452 barrier
= barrier_pkt
;
454 for (i
= 0; i
< to_read
; i
+= 4) {
455 buf_ptr
= buf
->data_pages
[cur
] + offset
;
456 read_data
= readl_relaxed(drvdata
->base
+
457 ETB_RAM_READ_DATA_REG
);
458 if (lost
&& *barrier
) {
459 read_data
= *barrier
;
463 *(u32
*)buf_ptr
= read_data
;
467 if (offset
>= PAGE_SIZE
) {
470 /* wrap around at the end of the buffer */
471 cur
&= buf
->nr_pages
- 1;
475 /* reset ETB buffer for next run */
476 writel_relaxed(0x0, drvdata
->base
+ ETB_RAM_READ_POINTER
);
477 writel_relaxed(0x0, drvdata
->base
+ ETB_RAM_WRITE_POINTER
);
480 * In snapshot mode all we have to do is communicate to
481 * perf_aux_output_end() the address of the current head. In full
482 * trace mode the same function expects a size to move rb->aux_head
486 local_set(&buf
->data_size
, (cur
* PAGE_SIZE
) + offset
);
488 local_add(to_read
, &buf
->data_size
);
490 etb_enable_hw(drvdata
);
491 CS_LOCK(drvdata
->base
);
494 static const struct coresight_ops_sink etb_sink_ops
= {
495 .enable
= etb_enable
,
496 .disable
= etb_disable
,
497 .alloc_buffer
= etb_alloc_buffer
,
498 .free_buffer
= etb_free_buffer
,
499 .set_buffer
= etb_set_buffer
,
500 .reset_buffer
= etb_reset_buffer
,
501 .update_buffer
= etb_update_buffer
,
504 static const struct coresight_ops etb_cs_ops
= {
505 .sink_ops
= &etb_sink_ops
,
508 static void etb_dump(struct etb_drvdata
*drvdata
)
512 spin_lock_irqsave(&drvdata
->spinlock
, flags
);
513 if (local_read(&drvdata
->mode
) == CS_MODE_SYSFS
) {
514 etb_disable_hw(drvdata
);
515 etb_dump_hw(drvdata
);
516 etb_enable_hw(drvdata
);
518 spin_unlock_irqrestore(&drvdata
->spinlock
, flags
);
520 dev_info(drvdata
->dev
, "ETB dumped\n");
523 static int etb_open(struct inode
*inode
, struct file
*file
)
525 struct etb_drvdata
*drvdata
= container_of(file
->private_data
,
526 struct etb_drvdata
, miscdev
);
528 if (local_cmpxchg(&drvdata
->reading
, 0, 1))
531 dev_dbg(drvdata
->dev
, "%s: successfully opened\n", __func__
);
535 static ssize_t
etb_read(struct file
*file
, char __user
*data
,
536 size_t len
, loff_t
*ppos
)
539 struct etb_drvdata
*drvdata
= container_of(file
->private_data
,
540 struct etb_drvdata
, miscdev
);
544 depth
= drvdata
->buffer_depth
;
545 if (*ppos
+ len
> depth
* 4)
546 len
= depth
* 4 - *ppos
;
548 if (copy_to_user(data
, drvdata
->buf
+ *ppos
, len
)) {
549 dev_dbg(drvdata
->dev
, "%s: copy_to_user failed\n", __func__
);
555 dev_dbg(drvdata
->dev
, "%s: %zu bytes copied, %d bytes left\n",
556 __func__
, len
, (int)(depth
* 4 - *ppos
));
560 static int etb_release(struct inode
*inode
, struct file
*file
)
562 struct etb_drvdata
*drvdata
= container_of(file
->private_data
,
563 struct etb_drvdata
, miscdev
);
564 local_set(&drvdata
->reading
, 0);
566 dev_dbg(drvdata
->dev
, "%s: released\n", __func__
);
570 static const struct file_operations etb_fops
= {
571 .owner
= THIS_MODULE
,
574 .release
= etb_release
,
578 #define coresight_etb10_reg(name, offset) \
579 coresight_simple_reg32(struct etb_drvdata, name, offset)
581 coresight_etb10_reg(rdp
, ETB_RAM_DEPTH_REG
);
582 coresight_etb10_reg(sts
, ETB_STATUS_REG
);
583 coresight_etb10_reg(rrp
, ETB_RAM_READ_POINTER
);
584 coresight_etb10_reg(rwp
, ETB_RAM_WRITE_POINTER
);
585 coresight_etb10_reg(trg
, ETB_TRG
);
586 coresight_etb10_reg(ctl
, ETB_CTL_REG
);
587 coresight_etb10_reg(ffsr
, ETB_FFSR
);
588 coresight_etb10_reg(ffcr
, ETB_FFCR
);
590 static struct attribute
*coresight_etb_mgmt_attrs
[] = {
602 static ssize_t
trigger_cntr_show(struct device
*dev
,
603 struct device_attribute
*attr
, char *buf
)
605 struct etb_drvdata
*drvdata
= dev_get_drvdata(dev
->parent
);
606 unsigned long val
= drvdata
->trigger_cntr
;
608 return sprintf(buf
, "%#lx\n", val
);
611 static ssize_t
trigger_cntr_store(struct device
*dev
,
612 struct device_attribute
*attr
,
613 const char *buf
, size_t size
)
617 struct etb_drvdata
*drvdata
= dev_get_drvdata(dev
->parent
);
619 ret
= kstrtoul(buf
, 16, &val
);
623 drvdata
->trigger_cntr
= val
;
626 static DEVICE_ATTR_RW(trigger_cntr
);
628 static struct attribute
*coresight_etb_attrs
[] = {
629 &dev_attr_trigger_cntr
.attr
,
633 static const struct attribute_group coresight_etb_group
= {
634 .attrs
= coresight_etb_attrs
,
637 static const struct attribute_group coresight_etb_mgmt_group
= {
638 .attrs
= coresight_etb_mgmt_attrs
,
642 const struct attribute_group
*coresight_etb_groups
[] = {
643 &coresight_etb_group
,
644 &coresight_etb_mgmt_group
,
648 static int etb_probe(struct amba_device
*adev
, const struct amba_id
*id
)
652 struct device
*dev
= &adev
->dev
;
653 struct coresight_platform_data
*pdata
= NULL
;
654 struct etb_drvdata
*drvdata
;
655 struct resource
*res
= &adev
->res
;
656 struct coresight_desc desc
= { 0 };
657 struct device_node
*np
= adev
->dev
.of_node
;
660 pdata
= of_get_coresight_platform_data(dev
, np
);
662 return PTR_ERR(pdata
);
663 adev
->dev
.platform_data
= pdata
;
666 drvdata
= devm_kzalloc(dev
, sizeof(*drvdata
), GFP_KERNEL
);
670 drvdata
->dev
= &adev
->dev
;
671 drvdata
->atclk
= devm_clk_get(&adev
->dev
, "atclk"); /* optional */
672 if (!IS_ERR(drvdata
->atclk
)) {
673 ret
= clk_prepare_enable(drvdata
->atclk
);
677 dev_set_drvdata(dev
, drvdata
);
679 /* validity for the resource is already checked by the AMBA core */
680 base
= devm_ioremap_resource(dev
, res
);
682 return PTR_ERR(base
);
684 drvdata
->base
= base
;
686 spin_lock_init(&drvdata
->spinlock
);
688 drvdata
->buffer_depth
= etb_get_buffer_depth(drvdata
);
689 pm_runtime_put(&adev
->dev
);
691 if (drvdata
->buffer_depth
& 0x80000000)
694 drvdata
->buf
= devm_kzalloc(dev
,
695 drvdata
->buffer_depth
* 4, GFP_KERNEL
);
699 desc
.type
= CORESIGHT_DEV_TYPE_SINK
;
700 desc
.subtype
.sink_subtype
= CORESIGHT_DEV_SUBTYPE_SINK_BUFFER
;
701 desc
.ops
= &etb_cs_ops
;
704 desc
.groups
= coresight_etb_groups
;
705 drvdata
->csdev
= coresight_register(&desc
);
706 if (IS_ERR(drvdata
->csdev
))
707 return PTR_ERR(drvdata
->csdev
);
709 drvdata
->miscdev
.name
= pdata
->name
;
710 drvdata
->miscdev
.minor
= MISC_DYNAMIC_MINOR
;
711 drvdata
->miscdev
.fops
= &etb_fops
;
712 ret
= misc_register(&drvdata
->miscdev
);
714 goto err_misc_register
;
719 coresight_unregister(drvdata
->csdev
);
724 static int etb_runtime_suspend(struct device
*dev
)
726 struct etb_drvdata
*drvdata
= dev_get_drvdata(dev
);
728 if (drvdata
&& !IS_ERR(drvdata
->atclk
))
729 clk_disable_unprepare(drvdata
->atclk
);
734 static int etb_runtime_resume(struct device
*dev
)
736 struct etb_drvdata
*drvdata
= dev_get_drvdata(dev
);
738 if (drvdata
&& !IS_ERR(drvdata
->atclk
))
739 clk_prepare_enable(drvdata
->atclk
);
745 static const struct dev_pm_ops etb_dev_pm_ops
= {
746 SET_RUNTIME_PM_OPS(etb_runtime_suspend
, etb_runtime_resume
, NULL
)
749 static const struct amba_id etb_ids
[] = {
757 static struct amba_driver etb_driver
= {
759 .name
= "coresight-etb10",
760 .owner
= THIS_MODULE
,
761 .pm
= &etb_dev_pm_ops
,
762 .suppress_bind_attrs
= true,
768 builtin_amba_driver(etb_driver
);