Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux-3.10.git] / arch / arm / kernel / etm.c
1 /*
2  * linux/arch/arm/kernel/etm.c
3  *
4  * Driver for ARM's Embedded Trace Macrocell and Embedded Trace Buffer.
5  *
6  * Copyright (C) 2009 Nokia Corporation.
7  * Alexander Shishkin
8  *
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.
12  */
13
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/types.h>
17 #include <linux/io.h>
18 #include <linux/sysrq.h>
19 #include <linux/device.h>
20 #include <linux/clk.h>
21 #include <linux/amba/bus.h>
22 #include <linux/fs.h>
23 #include <linux/uaccess.h>
24 #include <linux/miscdevice.h>
25 #include <linux/vmalloc.h>
26 #include <linux/mutex.h>
27 #include <linux/module.h>
28 #include <asm/hardware/coresight.h>
29 #include <asm/sections.h>
30
31 MODULE_LICENSE("GPL");
32 MODULE_AUTHOR("Alexander Shishkin");
33
34 /*
35  * ETM tracer state
36  */
37 struct tracectx {
38         unsigned int    etb_bufsz;
39         void __iomem    *etb_regs;
40         void __iomem    *etm_regs;
41         unsigned long   flags;
42         int             ncmppairs;
43         int             etm_portsz;
44         struct device   *dev;
45         struct clk      *emu_clk;
46         struct mutex    mutex;
47 };
48
49 static struct tracectx tracer;
50
51 static inline bool trace_isrunning(struct tracectx *t)
52 {
53         return !!(t->flags & TRACER_RUNNING);
54 }
55
56 static int etm_setup_address_range(struct tracectx *t, int n,
57                 unsigned long start, unsigned long end, int exclude, int data)
58 {
59         u32 flags = ETMAAT_ARM | ETMAAT_IGNCONTEXTID | ETMAAT_NSONLY | \
60                     ETMAAT_NOVALCMP;
61
62         if (n < 1 || n > t->ncmppairs)
63                 return -EINVAL;
64
65         /* comparators and ranges are numbered starting with 1 as opposed
66          * to bits in a word */
67         n--;
68
69         if (data)
70                 flags |= ETMAAT_DLOADSTORE;
71         else
72                 flags |= ETMAAT_IEXEC;
73
74         /* first comparator for the range */
75         etm_writel(t, flags, ETMR_COMP_ACC_TYPE(n * 2));
76         etm_writel(t, start, ETMR_COMP_VAL(n * 2));
77
78         /* second comparator is right next to it */
79         etm_writel(t, flags, ETMR_COMP_ACC_TYPE(n * 2 + 1));
80         etm_writel(t, end, ETMR_COMP_VAL(n * 2 + 1));
81
82         flags = exclude ? ETMTE_INCLEXCL : 0;
83         etm_writel(t, flags | (1 << n), ETMR_TRACEENCTRL);
84
85         return 0;
86 }
87
88 static int trace_start(struct tracectx *t)
89 {
90         u32 v;
91         unsigned long timeout = TRACER_TIMEOUT;
92
93         etb_unlock(t);
94
95         etb_writel(t, 0, ETBR_FORMATTERCTRL);
96         etb_writel(t, 1, ETBR_CTRL);
97
98         etb_lock(t);
99
100         /* configure etm */
101         v = ETMCTRL_OPTS | ETMCTRL_PROGRAM | ETMCTRL_PORTSIZE(t->etm_portsz);
102
103         if (t->flags & TRACER_CYCLE_ACC)
104                 v |= ETMCTRL_CYCLEACCURATE;
105
106         etm_unlock(t);
107
108         etm_writel(t, v, ETMR_CTRL);
109
110         while (!(etm_readl(t, ETMR_CTRL) & ETMCTRL_PROGRAM) && --timeout)
111                 ;
112         if (!timeout) {
113                 dev_dbg(t->dev, "Waiting for progbit to assert timed out\n");
114                 etm_lock(t);
115                 return -EFAULT;
116         }
117
118         etm_setup_address_range(t, 1, (unsigned long)_stext,
119                         (unsigned long)_etext, 0, 0);
120         etm_writel(t, 0, ETMR_TRACEENCTRL2);
121         etm_writel(t, 0, ETMR_TRACESSCTRL);
122         etm_writel(t, 0x6f, ETMR_TRACEENEVT);
123
124         v &= ~ETMCTRL_PROGRAM;
125         v |= ETMCTRL_PORTSEL;
126
127         etm_writel(t, v, ETMR_CTRL);
128
129         timeout = TRACER_TIMEOUT;
130         while (etm_readl(t, ETMR_CTRL) & ETMCTRL_PROGRAM && --timeout)
131                 ;
132         if (!timeout) {
133                 dev_dbg(t->dev, "Waiting for progbit to deassert timed out\n");
134                 etm_lock(t);
135                 return -EFAULT;
136         }
137
138         etm_lock(t);
139
140         t->flags |= TRACER_RUNNING;
141
142         return 0;
143 }
144
145 static int trace_stop(struct tracectx *t)
146 {
147         unsigned long timeout = TRACER_TIMEOUT;
148
149         etm_unlock(t);
150
151         etm_writel(t, 0x440, ETMR_CTRL);
152         while (!(etm_readl(t, ETMR_CTRL) & ETMCTRL_PROGRAM) && --timeout)
153                 ;
154         if (!timeout) {
155                 dev_dbg(t->dev, "Waiting for progbit to assert timed out\n");
156                 etm_lock(t);
157                 return -EFAULT;
158         }
159
160         etm_lock(t);
161
162         etb_unlock(t);
163         etb_writel(t, ETBFF_MANUAL_FLUSH, ETBR_FORMATTERCTRL);
164
165         timeout = TRACER_TIMEOUT;
166         while (etb_readl(t, ETBR_FORMATTERCTRL) &
167                         ETBFF_MANUAL_FLUSH && --timeout)
168                 ;
169         if (!timeout) {
170                 dev_dbg(t->dev, "Waiting for formatter flush to commence "
171                                 "timed out\n");
172                 etb_lock(t);
173                 return -EFAULT;
174         }
175
176         etb_writel(t, 0, ETBR_CTRL);
177
178         etb_lock(t);
179
180         t->flags &= ~TRACER_RUNNING;
181
182         return 0;
183 }
184
185 static int etb_getdatalen(struct tracectx *t)
186 {
187         u32 v;
188         int rp, wp;
189
190         v = etb_readl(t, ETBR_STATUS);
191
192         if (v & 1)
193                 return t->etb_bufsz;
194
195         rp = etb_readl(t, ETBR_READADDR);
196         wp = etb_readl(t, ETBR_WRITEADDR);
197
198         if (rp > wp) {
199                 etb_writel(t, 0, ETBR_READADDR);
200                 etb_writel(t, 0, ETBR_WRITEADDR);
201
202                 return 0;
203         }
204
205         return wp - rp;
206 }
207
208 /* sysrq+v will always stop the running trace and leave it at that */
209 static void etm_dump(void)
210 {
211         struct tracectx *t = &tracer;
212         u32 first = 0;
213         int length;
214
215         if (!t->etb_regs) {
216                 printk(KERN_INFO "No tracing hardware found\n");
217                 return;
218         }
219
220         if (trace_isrunning(t))
221                 trace_stop(t);
222
223         etb_unlock(t);
224
225         length = etb_getdatalen(t);
226
227         if (length == t->etb_bufsz)
228                 first = etb_readl(t, ETBR_WRITEADDR);
229
230         etb_writel(t, first, ETBR_READADDR);
231
232         printk(KERN_INFO "Trace buffer contents length: %d\n", length);
233         printk(KERN_INFO "--- ETB buffer begin ---\n");
234         for (; length; length--)
235                 printk("%08x", cpu_to_be32(etb_readl(t, ETBR_READMEM)));
236         printk(KERN_INFO "\n--- ETB buffer end ---\n");
237
238         /* deassert the overflow bit */
239         etb_writel(t, 1, ETBR_CTRL);
240         etb_writel(t, 0, ETBR_CTRL);
241
242         etb_writel(t, 0, ETBR_TRIGGERCOUNT);
243         etb_writel(t, 0, ETBR_READADDR);
244         etb_writel(t, 0, ETBR_WRITEADDR);
245
246         etb_lock(t);
247 }
248
249 static void sysrq_etm_dump(int key)
250 {
251         dev_dbg(tracer.dev, "Dumping ETB buffer\n");
252         etm_dump();
253 }
254
255 static struct sysrq_key_op sysrq_etm_op = {
256         .handler = sysrq_etm_dump,
257         .help_msg = "etm-buffer-dump(v)",
258         .action_msg = "etm",
259 };
260
261 static int etb_open(struct inode *inode, struct file *file)
262 {
263         if (!tracer.etb_regs)
264                 return -ENODEV;
265
266         file->private_data = &tracer;
267
268         return nonseekable_open(inode, file);
269 }
270
271 static ssize_t etb_read(struct file *file, char __user *data,
272                 size_t len, loff_t *ppos)
273 {
274         int total, i;
275         long length;
276         struct tracectx *t = file->private_data;
277         u32 first = 0;
278         u32 *buf;
279
280         mutex_lock(&t->mutex);
281
282         if (trace_isrunning(t)) {
283                 length = 0;
284                 goto out;
285         }
286
287         etb_unlock(t);
288
289         total = etb_getdatalen(t);
290         if (total == t->etb_bufsz)
291                 first = etb_readl(t, ETBR_WRITEADDR);
292
293         etb_writel(t, first, ETBR_READADDR);
294
295         length = min(total * 4, (int)len);
296         buf = vmalloc(length);
297
298         dev_dbg(t->dev, "ETB buffer length: %d\n", total);
299         dev_dbg(t->dev, "ETB status reg: %x\n", etb_readl(t, ETBR_STATUS));
300         for (i = 0; i < length / 4; i++)
301                 buf[i] = etb_readl(t, ETBR_READMEM);
302
303         /* the only way to deassert overflow bit in ETB status is this */
304         etb_writel(t, 1, ETBR_CTRL);
305         etb_writel(t, 0, ETBR_CTRL);
306
307         etb_writel(t, 0, ETBR_WRITEADDR);
308         etb_writel(t, 0, ETBR_READADDR);
309         etb_writel(t, 0, ETBR_TRIGGERCOUNT);
310
311         etb_lock(t);
312
313         length -= copy_to_user(data, buf, length);
314         vfree(buf);
315
316 out:
317         mutex_unlock(&t->mutex);
318
319         return length;
320 }
321
322 static int etb_release(struct inode *inode, struct file *file)
323 {
324         /* there's nothing to do here, actually */
325         return 0;
326 }
327
328 static const struct file_operations etb_fops = {
329         .owner = THIS_MODULE,
330         .read = etb_read,
331         .open = etb_open,
332         .release = etb_release,
333         .llseek = no_llseek,
334 };
335
336 static struct miscdevice etb_miscdev = {
337         .name = "tracebuf",
338         .minor = 0,
339         .fops = &etb_fops,
340 };
341
342 static int etb_probe(struct amba_device *dev, const struct amba_id *id)
343 {
344         struct tracectx *t = &tracer;
345         int ret = 0;
346
347         ret = amba_request_regions(dev, NULL);
348         if (ret)
349                 goto out;
350
351         t->etb_regs = ioremap_nocache(dev->res.start, resource_size(&dev->res));
352         if (!t->etb_regs) {
353                 ret = -ENOMEM;
354                 goto out_release;
355         }
356
357         amba_set_drvdata(dev, t);
358
359         etb_miscdev.parent = &dev->dev;
360
361         ret = misc_register(&etb_miscdev);
362         if (ret)
363                 goto out_unmap;
364
365         t->emu_clk = clk_get(&dev->dev, "emu_src_ck");
366         if (IS_ERR(t->emu_clk)) {
367                 dev_dbg(&dev->dev, "Failed to obtain emu_src_ck.\n");
368                 return -EFAULT;
369         }
370
371         clk_enable(t->emu_clk);
372
373         etb_unlock(t);
374         t->etb_bufsz = etb_readl(t, ETBR_DEPTH);
375         dev_dbg(&dev->dev, "Size: %x\n", t->etb_bufsz);
376
377         /* make sure trace capture is disabled */
378         etb_writel(t, 0, ETBR_CTRL);
379         etb_writel(t, 0x1000, ETBR_FORMATTERCTRL);
380         etb_lock(t);
381
382         dev_dbg(&dev->dev, "ETB AMBA driver initialized.\n");
383
384 out:
385         return ret;
386
387 out_unmap:
388         amba_set_drvdata(dev, NULL);
389         iounmap(t->etb_regs);
390
391 out_release:
392         amba_release_regions(dev);
393
394         return ret;
395 }
396
397 static int etb_remove(struct amba_device *dev)
398 {
399         struct tracectx *t = amba_get_drvdata(dev);
400
401         amba_set_drvdata(dev, NULL);
402
403         iounmap(t->etb_regs);
404         t->etb_regs = NULL;
405
406         clk_disable(t->emu_clk);
407         clk_put(t->emu_clk);
408
409         amba_release_regions(dev);
410
411         return 0;
412 }
413
414 static struct amba_id etb_ids[] = {
415         {
416                 .id     = 0x0003b907,
417                 .mask   = 0x0007ffff,
418         },
419         { 0, 0 },
420 };
421
422 static struct amba_driver etb_driver = {
423         .drv            = {
424                 .name   = "etb",
425                 .owner  = THIS_MODULE,
426         },
427         .probe          = etb_probe,
428         .remove         = etb_remove,
429         .id_table       = etb_ids,
430 };
431
432 /* use a sysfs file "trace_running" to start/stop tracing */
433 static ssize_t trace_running_show(struct kobject *kobj,
434                                   struct kobj_attribute *attr,
435                                   char *buf)
436 {
437         return sprintf(buf, "%x\n", trace_isrunning(&tracer));
438 }
439
440 static ssize_t trace_running_store(struct kobject *kobj,
441                                    struct kobj_attribute *attr,
442                                    const char *buf, size_t n)
443 {
444         unsigned int value;
445         int ret;
446
447         if (sscanf(buf, "%u", &value) != 1)
448                 return -EINVAL;
449
450         mutex_lock(&tracer.mutex);
451         ret = value ? trace_start(&tracer) : trace_stop(&tracer);
452         mutex_unlock(&tracer.mutex);
453
454         return ret ? : n;
455 }
456
457 static struct kobj_attribute trace_running_attr =
458         __ATTR(trace_running, 0644, trace_running_show, trace_running_store);
459
460 static ssize_t trace_info_show(struct kobject *kobj,
461                                   struct kobj_attribute *attr,
462                                   char *buf)
463 {
464         u32 etb_wa, etb_ra, etb_st, etb_fc, etm_ctrl, etm_st;
465         int datalen;
466
467         etb_unlock(&tracer);
468         datalen = etb_getdatalen(&tracer);
469         etb_wa = etb_readl(&tracer, ETBR_WRITEADDR);
470         etb_ra = etb_readl(&tracer, ETBR_READADDR);
471         etb_st = etb_readl(&tracer, ETBR_STATUS);
472         etb_fc = etb_readl(&tracer, ETBR_FORMATTERCTRL);
473         etb_lock(&tracer);
474
475         etm_unlock(&tracer);
476         etm_ctrl = etm_readl(&tracer, ETMR_CTRL);
477         etm_st = etm_readl(&tracer, ETMR_STATUS);
478         etm_lock(&tracer);
479
480         return sprintf(buf, "Trace buffer len: %d\nComparator pairs: %d\n"
481                         "ETBR_WRITEADDR:\t%08x\n"
482                         "ETBR_READADDR:\t%08x\n"
483                         "ETBR_STATUS:\t%08x\n"
484                         "ETBR_FORMATTERCTRL:\t%08x\n"
485                         "ETMR_CTRL:\t%08x\n"
486                         "ETMR_STATUS:\t%08x\n",
487                         datalen,
488                         tracer.ncmppairs,
489                         etb_wa,
490                         etb_ra,
491                         etb_st,
492                         etb_fc,
493                         etm_ctrl,
494                         etm_st
495                         );
496 }
497
498 static struct kobj_attribute trace_info_attr =
499         __ATTR(trace_info, 0444, trace_info_show, NULL);
500
501 static ssize_t trace_mode_show(struct kobject *kobj,
502                                   struct kobj_attribute *attr,
503                                   char *buf)
504 {
505         return sprintf(buf, "%d %d\n",
506                         !!(tracer.flags & TRACER_CYCLE_ACC),
507                         tracer.etm_portsz);
508 }
509
510 static ssize_t trace_mode_store(struct kobject *kobj,
511                                    struct kobj_attribute *attr,
512                                    const char *buf, size_t n)
513 {
514         unsigned int cycacc, portsz;
515
516         if (sscanf(buf, "%u %u", &cycacc, &portsz) != 2)
517                 return -EINVAL;
518
519         mutex_lock(&tracer.mutex);
520         if (cycacc)
521                 tracer.flags |= TRACER_CYCLE_ACC;
522         else
523                 tracer.flags &= ~TRACER_CYCLE_ACC;
524
525         tracer.etm_portsz = portsz & 0x0f;
526         mutex_unlock(&tracer.mutex);
527
528         return n;
529 }
530
531 static struct kobj_attribute trace_mode_attr =
532         __ATTR(trace_mode, 0644, trace_mode_show, trace_mode_store);
533
534 static int etm_probe(struct amba_device *dev, const struct amba_id *id)
535 {
536         struct tracectx *t = &tracer;
537         int ret = 0;
538
539         if (t->etm_regs) {
540                 dev_dbg(&dev->dev, "ETM already initialized\n");
541                 ret = -EBUSY;
542                 goto out;
543         }
544
545         ret = amba_request_regions(dev, NULL);
546         if (ret)
547                 goto out;
548
549         t->etm_regs = ioremap_nocache(dev->res.start, resource_size(&dev->res));
550         if (!t->etm_regs) {
551                 ret = -ENOMEM;
552                 goto out_release;
553         }
554
555         amba_set_drvdata(dev, t);
556
557         mutex_init(&t->mutex);
558         t->dev = &dev->dev;
559         t->flags = TRACER_CYCLE_ACC;
560         t->etm_portsz = 1;
561
562         etm_unlock(t);
563         (void)etm_readl(t, ETMMR_PDSR);
564         /* dummy first read */
565         (void)etm_readl(&tracer, ETMMR_OSSRR);
566
567         t->ncmppairs = etm_readl(t, ETMR_CONFCODE) & 0xf;
568         etm_writel(t, 0x440, ETMR_CTRL);
569         etm_lock(t);
570
571         ret = sysfs_create_file(&dev->dev.kobj,
572                         &trace_running_attr.attr);
573         if (ret)
574                 goto out_unmap;
575
576         /* failing to create any of these two is not fatal */
577         ret = sysfs_create_file(&dev->dev.kobj, &trace_info_attr.attr);
578         if (ret)
579                 dev_dbg(&dev->dev, "Failed to create trace_info in sysfs\n");
580
581         ret = sysfs_create_file(&dev->dev.kobj, &trace_mode_attr.attr);
582         if (ret)
583                 dev_dbg(&dev->dev, "Failed to create trace_mode in sysfs\n");
584
585         dev_dbg(t->dev, "ETM AMBA driver initialized.\n");
586
587 out:
588         return ret;
589
590 out_unmap:
591         amba_set_drvdata(dev, NULL);
592         iounmap(t->etm_regs);
593
594 out_release:
595         amba_release_regions(dev);
596
597         return ret;
598 }
599
600 static int etm_remove(struct amba_device *dev)
601 {
602         struct tracectx *t = amba_get_drvdata(dev);
603
604         amba_set_drvdata(dev, NULL);
605
606         iounmap(t->etm_regs);
607         t->etm_regs = NULL;
608
609         amba_release_regions(dev);
610
611         sysfs_remove_file(&dev->dev.kobj, &trace_running_attr.attr);
612         sysfs_remove_file(&dev->dev.kobj, &trace_info_attr.attr);
613         sysfs_remove_file(&dev->dev.kobj, &trace_mode_attr.attr);
614
615         return 0;
616 }
617
618 static struct amba_id etm_ids[] = {
619         {
620                 .id     = 0x0003b921,
621                 .mask   = 0x0007ffff,
622         },
623         { 0, 0 },
624 };
625
626 static struct amba_driver etm_driver = {
627         .drv            = {
628                 .name   = "etm",
629                 .owner  = THIS_MODULE,
630         },
631         .probe          = etm_probe,
632         .remove         = etm_remove,
633         .id_table       = etm_ids,
634 };
635
636 static int __init etm_init(void)
637 {
638         int retval;
639
640         retval = amba_driver_register(&etb_driver);
641         if (retval) {
642                 printk(KERN_ERR "Failed to register etb\n");
643                 return retval;
644         }
645
646         retval = amba_driver_register(&etm_driver);
647         if (retval) {
648                 amba_driver_unregister(&etb_driver);
649                 printk(KERN_ERR "Failed to probe etm\n");
650                 return retval;
651         }
652
653         /* not being able to install this handler is not fatal */
654         (void)register_sysrq_key('v', &sysrq_etm_op);
655
656         return 0;
657 }
658
659 device_initcall(etm_init);
660