2 * linux/arch/arm/kernel/etm.c
4 * Driver for ARM's Embedded Trace Macrocell and Embedded Trace Buffer.
6 * Copyright (C) 2009 Nokia Corporation.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/types.h>
18 #include <linux/sysrq.h>
19 #include <linux/device.h>
20 #include <linux/clk.h>
21 #include <linux/amba/bus.h>
23 #include <linux/uaccess.h>
24 #include <linux/miscdevice.h>
25 #include <linux/vmalloc.h>
26 #include <linux/mutex.h>
27 #include <asm/hardware/coresight.h>
28 #include <asm/sections.h>
30 MODULE_LICENSE("GPL");
31 MODULE_AUTHOR("Alexander Shishkin");
33 static struct tracectx tracer
;
35 static inline bool trace_isrunning(struct tracectx
*t
)
37 return !!(t
->flags
& TRACER_RUNNING
);
40 static int etm_setup_address_range(struct tracectx
*t
, int n
,
41 unsigned long start
, unsigned long end
, int exclude
, int data
)
43 u32 flags
= ETMAAT_ARM
| ETMAAT_IGNCONTEXTID
| ETMAAT_NSONLY
| \
46 if (n
< 1 || n
> t
->ncmppairs
)
49 /* comparators and ranges are numbered starting with 1 as opposed
50 * to bits in a word */
54 flags
|= ETMAAT_DLOADSTORE
;
56 flags
|= ETMAAT_IEXEC
;
58 /* first comparator for the range */
59 etm_writel(t
, flags
, ETMR_COMP_ACC_TYPE(n
* 2));
60 etm_writel(t
, start
, ETMR_COMP_VAL(n
* 2));
62 /* second comparator is right next to it */
63 etm_writel(t
, flags
, ETMR_COMP_ACC_TYPE(n
* 2 + 1));
64 etm_writel(t
, end
, ETMR_COMP_VAL(n
* 2 + 1));
66 flags
= exclude
? ETMTE_INCLEXCL
: 0;
67 etm_writel(t
, flags
| (1 << n
), ETMR_TRACEENCTRL
);
72 static int trace_start(struct tracectx
*t
)
75 unsigned long timeout
= TRACER_TIMEOUT
;
79 etb_writel(t
, 0, ETBR_FORMATTERCTRL
);
80 etb_writel(t
, 1, ETBR_CTRL
);
85 v
= ETMCTRL_OPTS
| ETMCTRL_PROGRAM
| ETMCTRL_PORTSIZE(t
->etm_portsz
);
87 if (t
->flags
& TRACER_CYCLE_ACC
)
88 v
|= ETMCTRL_CYCLEACCURATE
;
92 etm_writel(t
, v
, ETMR_CTRL
);
94 while (!(etm_readl(t
, ETMR_CTRL
) & ETMCTRL_PROGRAM
) && --timeout
)
97 dev_dbg(t
->dev
, "Waiting for progbit to assert timed out\n");
102 etm_setup_address_range(t
, 1, (unsigned long)_stext
,
103 (unsigned long)_etext
, 0, 0);
104 etm_writel(t
, 0, ETMR_TRACEENCTRL2
);
105 etm_writel(t
, 0, ETMR_TRACESSCTRL
);
106 etm_writel(t
, 0x6f, ETMR_TRACEENEVT
);
108 v
&= ~ETMCTRL_PROGRAM
;
109 v
|= ETMCTRL_PORTSEL
;
111 etm_writel(t
, v
, ETMR_CTRL
);
113 timeout
= TRACER_TIMEOUT
;
114 while (etm_readl(t
, ETMR_CTRL
) & ETMCTRL_PROGRAM
&& --timeout
)
117 dev_dbg(t
->dev
, "Waiting for progbit to deassert timed out\n");
124 t
->flags
|= TRACER_RUNNING
;
129 static int trace_stop(struct tracectx
*t
)
131 unsigned long timeout
= TRACER_TIMEOUT
;
135 etm_writel(t
, 0x440, ETMR_CTRL
);
136 while (!(etm_readl(t
, ETMR_CTRL
) & ETMCTRL_PROGRAM
) && --timeout
)
139 dev_dbg(t
->dev
, "Waiting for progbit to assert timed out\n");
147 etb_writel(t
, ETBFF_MANUAL_FLUSH
, ETBR_FORMATTERCTRL
);
149 timeout
= TRACER_TIMEOUT
;
150 while (etb_readl(t
, ETBR_FORMATTERCTRL
) &
151 ETBFF_MANUAL_FLUSH
&& --timeout
)
154 dev_dbg(t
->dev
, "Waiting for formatter flush to commence "
160 etb_writel(t
, 0, ETBR_CTRL
);
164 t
->flags
&= ~TRACER_RUNNING
;
169 static int etb_getdatalen(struct tracectx
*t
)
174 v
= etb_readl(t
, ETBR_STATUS
);
179 rp
= etb_readl(t
, ETBR_READADDR
);
180 wp
= etb_readl(t
, ETBR_WRITEADDR
);
183 etb_writel(t
, 0, ETBR_READADDR
);
184 etb_writel(t
, 0, ETBR_WRITEADDR
);
192 /* sysrq+v will always stop the running trace and leave it at that */
193 static void etm_dump(void)
195 struct tracectx
*t
= &tracer
;
200 printk(KERN_INFO
"No tracing hardware found\n");
204 if (trace_isrunning(t
))
209 length
= etb_getdatalen(t
);
211 if (length
== t
->etb_bufsz
)
212 first
= etb_readl(t
, ETBR_WRITEADDR
);
214 etb_writel(t
, first
, ETBR_READADDR
);
216 printk(KERN_INFO
"Trace buffer contents length: %d\n", length
);
217 printk(KERN_INFO
"--- ETB buffer begin ---\n");
218 for (; length
; length
--)
219 printk("%08x", cpu_to_be32(etb_readl(t
, ETBR_READMEM
)));
220 printk(KERN_INFO
"\n--- ETB buffer end ---\n");
222 /* deassert the overflow bit */
223 etb_writel(t
, 1, ETBR_CTRL
);
224 etb_writel(t
, 0, ETBR_CTRL
);
226 etb_writel(t
, 0, ETBR_TRIGGERCOUNT
);
227 etb_writel(t
, 0, ETBR_READADDR
);
228 etb_writel(t
, 0, ETBR_WRITEADDR
);
233 static void sysrq_etm_dump(int key
)
235 dev_dbg(tracer
.dev
, "Dumping ETB buffer\n");
239 static struct sysrq_key_op sysrq_etm_op
= {
240 .handler
= sysrq_etm_dump
,
241 .help_msg
= "ETM buffer dump",
245 static int etb_open(struct inode
*inode
, struct file
*file
)
247 if (!tracer
.etb_regs
)
250 file
->private_data
= &tracer
;
252 return nonseekable_open(inode
, file
);
255 static ssize_t
etb_read(struct file
*file
, char __user
*data
,
256 size_t len
, loff_t
*ppos
)
260 struct tracectx
*t
= file
->private_data
;
264 mutex_lock(&t
->mutex
);
266 if (trace_isrunning(t
)) {
273 total
= etb_getdatalen(t
);
274 if (total
== t
->etb_bufsz
)
275 first
= etb_readl(t
, ETBR_WRITEADDR
);
277 etb_writel(t
, first
, ETBR_READADDR
);
279 length
= min(total
* 4, (int)len
);
280 buf
= vmalloc(length
);
282 dev_dbg(t
->dev
, "ETB buffer length: %d\n", total
);
283 dev_dbg(t
->dev
, "ETB status reg: %x\n", etb_readl(t
, ETBR_STATUS
));
284 for (i
= 0; i
< length
/ 4; i
++)
285 buf
[i
] = etb_readl(t
, ETBR_READMEM
);
287 /* the only way to deassert overflow bit in ETB status is this */
288 etb_writel(t
, 1, ETBR_CTRL
);
289 etb_writel(t
, 0, ETBR_CTRL
);
291 etb_writel(t
, 0, ETBR_WRITEADDR
);
292 etb_writel(t
, 0, ETBR_READADDR
);
293 etb_writel(t
, 0, ETBR_TRIGGERCOUNT
);
297 length
-= copy_to_user(data
, buf
, length
);
301 mutex_unlock(&t
->mutex
);
306 static int etb_release(struct inode
*inode
, struct file
*file
)
308 /* there's nothing to do here, actually */
312 static const struct file_operations etb_fops
= {
313 .owner
= THIS_MODULE
,
316 .release
= etb_release
,
320 static struct miscdevice etb_miscdev
= {
326 static int __init
etb_probe(struct amba_device
*dev
, struct amba_id
*id
)
328 struct tracectx
*t
= &tracer
;
331 ret
= amba_request_regions(dev
, NULL
);
335 t
->etb_regs
= ioremap_nocache(dev
->res
.start
, resource_size(&dev
->res
));
341 amba_set_drvdata(dev
, t
);
343 etb_miscdev
.parent
= &dev
->dev
;
345 ret
= misc_register(&etb_miscdev
);
349 t
->emu_clk
= clk_get(&dev
->dev
, "emu_src_ck");
350 if (IS_ERR(t
->emu_clk
)) {
351 dev_dbg(&dev
->dev
, "Failed to obtain emu_src_ck.\n");
355 clk_enable(t
->emu_clk
);
358 t
->etb_bufsz
= etb_readl(t
, ETBR_DEPTH
);
359 dev_dbg(&dev
->dev
, "Size: %x\n", t
->etb_bufsz
);
361 /* make sure trace capture is disabled */
362 etb_writel(t
, 0, ETBR_CTRL
);
363 etb_writel(t
, 0x1000, ETBR_FORMATTERCTRL
);
366 dev_dbg(&dev
->dev
, "ETB AMBA driver initialized.\n");
372 amba_set_drvdata(dev
, NULL
);
373 iounmap(t
->etb_regs
);
376 amba_release_regions(dev
);
381 static int etb_remove(struct amba_device
*dev
)
383 struct tracectx
*t
= amba_get_drvdata(dev
);
385 amba_set_drvdata(dev
, NULL
);
387 iounmap(t
->etb_regs
);
390 clk_disable(t
->emu_clk
);
393 amba_release_regions(dev
);
398 static struct amba_id etb_ids
[] = {
406 static struct amba_driver etb_driver
= {
409 .owner
= THIS_MODULE
,
412 .remove
= etb_remove
,
416 /* use a sysfs file "trace_running" to start/stop tracing */
417 static ssize_t
trace_running_show(struct kobject
*kobj
,
418 struct kobj_attribute
*attr
,
421 return sprintf(buf
, "%x\n", trace_isrunning(&tracer
));
424 static ssize_t
trace_running_store(struct kobject
*kobj
,
425 struct kobj_attribute
*attr
,
426 const char *buf
, size_t n
)
431 if (sscanf(buf
, "%u", &value
) != 1)
434 mutex_lock(&tracer
.mutex
);
435 ret
= value
? trace_start(&tracer
) : trace_stop(&tracer
);
436 mutex_unlock(&tracer
.mutex
);
441 static struct kobj_attribute trace_running_attr
=
442 __ATTR(trace_running
, 0644, trace_running_show
, trace_running_store
);
444 static ssize_t
trace_info_show(struct kobject
*kobj
,
445 struct kobj_attribute
*attr
,
448 u32 etb_wa
, etb_ra
, etb_st
, etb_fc
, etm_ctrl
, etm_st
;
452 datalen
= etb_getdatalen(&tracer
);
453 etb_wa
= etb_readl(&tracer
, ETBR_WRITEADDR
);
454 etb_ra
= etb_readl(&tracer
, ETBR_READADDR
);
455 etb_st
= etb_readl(&tracer
, ETBR_STATUS
);
456 etb_fc
= etb_readl(&tracer
, ETBR_FORMATTERCTRL
);
460 etm_ctrl
= etm_readl(&tracer
, ETMR_CTRL
);
461 etm_st
= etm_readl(&tracer
, ETMR_STATUS
);
464 return sprintf(buf
, "Trace buffer len: %d\nComparator pairs: %d\n"
465 "ETBR_WRITEADDR:\t%08x\n"
466 "ETBR_READADDR:\t%08x\n"
467 "ETBR_STATUS:\t%08x\n"
468 "ETBR_FORMATTERCTRL:\t%08x\n"
470 "ETMR_STATUS:\t%08x\n",
482 static struct kobj_attribute trace_info_attr
=
483 __ATTR(trace_info
, 0444, trace_info_show
, NULL
);
485 static ssize_t
trace_mode_show(struct kobject
*kobj
,
486 struct kobj_attribute
*attr
,
489 return sprintf(buf
, "%d %d\n",
490 !!(tracer
.flags
& TRACER_CYCLE_ACC
),
494 static ssize_t
trace_mode_store(struct kobject
*kobj
,
495 struct kobj_attribute
*attr
,
496 const char *buf
, size_t n
)
498 unsigned int cycacc
, portsz
;
500 if (sscanf(buf
, "%u %u", &cycacc
, &portsz
) != 2)
503 mutex_lock(&tracer
.mutex
);
505 tracer
.flags
|= TRACER_CYCLE_ACC
;
507 tracer
.flags
&= ~TRACER_CYCLE_ACC
;
509 tracer
.etm_portsz
= portsz
& 0x0f;
510 mutex_unlock(&tracer
.mutex
);
515 static struct kobj_attribute trace_mode_attr
=
516 __ATTR(trace_mode
, 0644, trace_mode_show
, trace_mode_store
);
518 static int __init
etm_probe(struct amba_device
*dev
, struct amba_id
*id
)
520 struct tracectx
*t
= &tracer
;
524 dev_dbg(&dev
->dev
, "ETM already initialized\n");
529 ret
= amba_request_regions(dev
, NULL
);
533 t
->etm_regs
= ioremap_nocache(dev
->res
.start
, resource_size(&dev
->res
));
539 amba_set_drvdata(dev
, t
);
541 mutex_init(&t
->mutex
);
543 t
->flags
= TRACER_CYCLE_ACC
;
547 (void)etm_readl(t
, ETMMR_PDSR
);
548 /* dummy first read */
549 (void)etm_readl(&tracer
, ETMMR_OSSRR
);
551 t
->ncmppairs
= etm_readl(t
, ETMR_CONFCODE
) & 0xf;
552 etm_writel(t
, 0x440, ETMR_CTRL
);
555 ret
= sysfs_create_file(&dev
->dev
.kobj
,
556 &trace_running_attr
.attr
);
560 /* failing to create any of these two is not fatal */
561 ret
= sysfs_create_file(&dev
->dev
.kobj
, &trace_info_attr
.attr
);
563 dev_dbg(&dev
->dev
, "Failed to create trace_info in sysfs\n");
565 ret
= sysfs_create_file(&dev
->dev
.kobj
, &trace_mode_attr
.attr
);
567 dev_dbg(&dev
->dev
, "Failed to create trace_mode in sysfs\n");
569 dev_dbg(t
->dev
, "ETM AMBA driver initialized.\n");
575 amba_set_drvdata(dev
, NULL
);
576 iounmap(t
->etm_regs
);
579 amba_release_regions(dev
);
584 static int etm_remove(struct amba_device
*dev
)
586 struct tracectx
*t
= amba_get_drvdata(dev
);
588 amba_set_drvdata(dev
, NULL
);
590 iounmap(t
->etm_regs
);
593 amba_release_regions(dev
);
595 sysfs_remove_file(&dev
->dev
.kobj
, &trace_running_attr
.attr
);
596 sysfs_remove_file(&dev
->dev
.kobj
, &trace_info_attr
.attr
);
597 sysfs_remove_file(&dev
->dev
.kobj
, &trace_mode_attr
.attr
);
602 static struct amba_id etm_ids
[] = {
610 static struct amba_driver etm_driver
= {
613 .owner
= THIS_MODULE
,
616 .remove
= etm_remove
,
620 static int __init
etm_init(void)
624 retval
= amba_driver_register(&etb_driver
);
626 printk(KERN_ERR
"Failed to register etb\n");
630 retval
= amba_driver_register(&etm_driver
);
632 amba_driver_unregister(&etb_driver
);
633 printk(KERN_ERR
"Failed to probe etm\n");
637 /* not being able to install this handler is not fatal */
638 (void)register_sysrq_key('v', &sysrq_etm_op
);
643 device_initcall(etm_init
);