1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
4 *
5 * Description: CoreSight Program Flow Trace driver
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/moduleparam.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/slab.h>
17 #include <linux/delay.h>
18 #include <linux/smp.h>
19 #include <linux/sysfs.h>
20 #include <linux/stat.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/cpu.h>
23 #include <linux/of.h>
24 #include <linux/coresight.h>
25 #include <linux/coresight-pmu.h>
26 #include <linux/amba/bus.h>
27 #include <linux/seq_file.h>
28 #include <linux/uaccess.h>
29 #include <linux/clk.h>
30 #include <linux/perf_event.h>
31 #include <asm/sections.h>
32
33 #include "coresight-etm.h"
34 #include "coresight-etm-perf.h"
35 #include "coresight-trace-id.h"
36
37 /*
38 * Not really modular but using module_param is the easiest way to
39 * remain consistent with existing use cases for now.
40 */
41 static int boot_enable;
42 module_param_named(boot_enable, boot_enable, int, S_IRUGO);
43
44 static struct etm_drvdata *etmdrvdata[NR_CPUS];
45
46 static enum cpuhp_state hp_online;
47
48 /*
49 * Memory mapped writes to clear os lock are not supported on some processors
50 * and OS lock must be unlocked before any memory mapped access on such
51 * processors, otherwise memory mapped reads/writes will be invalid.
52 */
etm_os_unlock(struct etm_drvdata * drvdata)53 static void etm_os_unlock(struct etm_drvdata *drvdata)
54 {
55 /* Writing any value to ETMOSLAR unlocks the trace registers */
56 etm_writel(drvdata, 0x0, ETMOSLAR);
57 drvdata->os_unlock = true;
58 isb();
59 }
60
etm_set_pwrdwn(struct etm_drvdata * drvdata)61 static void etm_set_pwrdwn(struct etm_drvdata *drvdata)
62 {
63 u32 etmcr;
64
65 /* Ensure pending cp14 accesses complete before setting pwrdwn */
66 mb();
67 isb();
68 etmcr = etm_readl(drvdata, ETMCR);
69 etmcr |= ETMCR_PWD_DWN;
70 etm_writel(drvdata, etmcr, ETMCR);
71 }
72
etm_clr_pwrdwn(struct etm_drvdata * drvdata)73 static void etm_clr_pwrdwn(struct etm_drvdata *drvdata)
74 {
75 u32 etmcr;
76
77 etmcr = etm_readl(drvdata, ETMCR);
78 etmcr &= ~ETMCR_PWD_DWN;
79 etm_writel(drvdata, etmcr, ETMCR);
80 /* Ensure pwrup completes before subsequent cp14 accesses */
81 mb();
82 isb();
83 }
84
etm_set_pwrup(struct etm_drvdata * drvdata)85 static void etm_set_pwrup(struct etm_drvdata *drvdata)
86 {
87 u32 etmpdcr;
88
89 etmpdcr = readl_relaxed(drvdata->base + ETMPDCR);
90 etmpdcr |= ETMPDCR_PWD_UP;
91 writel_relaxed(etmpdcr, drvdata->base + ETMPDCR);
92 /* Ensure pwrup completes before subsequent cp14 accesses */
93 mb();
94 isb();
95 }
96
etm_clr_pwrup(struct etm_drvdata * drvdata)97 static void etm_clr_pwrup(struct etm_drvdata *drvdata)
98 {
99 u32 etmpdcr;
100
101 /* Ensure pending cp14 accesses complete before clearing pwrup */
102 mb();
103 isb();
104 etmpdcr = readl_relaxed(drvdata->base + ETMPDCR);
105 etmpdcr &= ~ETMPDCR_PWD_UP;
106 writel_relaxed(etmpdcr, drvdata->base + ETMPDCR);
107 }
108
109 /**
110 * coresight_timeout_etm - loop until a bit has changed to a specific state.
111 * @drvdata: etm's private data structure.
112 * @offset: address of a register, starting from @addr.
113 * @position: the position of the bit of interest.
114 * @value: the value the bit should have.
115 *
116 * Basically the same as @coresight_timeout except for the register access
117 * method where we have to account for CP14 configurations.
118
119 * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
120 * TIMEOUT_US has elapsed, which ever happens first.
121 */
122
coresight_timeout_etm(struct etm_drvdata * drvdata,u32 offset,int position,int value)123 static int coresight_timeout_etm(struct etm_drvdata *drvdata, u32 offset,
124 int position, int value)
125 {
126 int i;
127 u32 val;
128
129 for (i = TIMEOUT_US; i > 0; i--) {
130 val = etm_readl(drvdata, offset);
131 /* Waiting on the bit to go from 0 to 1 */
132 if (value) {
133 if (val & BIT(position))
134 return 0;
135 /* Waiting on the bit to go from 1 to 0 */
136 } else {
137 if (!(val & BIT(position)))
138 return 0;
139 }
140
141 /*
142 * Delay is arbitrary - the specification doesn't say how long
143 * we are expected to wait. Extra check required to make sure
144 * we don't wait needlessly on the last iteration.
145 */
146 if (i - 1)
147 udelay(1);
148 }
149
150 return -EAGAIN;
151 }
152
153
etm_set_prog(struct etm_drvdata * drvdata)154 static void etm_set_prog(struct etm_drvdata *drvdata)
155 {
156 u32 etmcr;
157
158 etmcr = etm_readl(drvdata, ETMCR);
159 etmcr |= ETMCR_ETM_PRG;
160 etm_writel(drvdata, etmcr, ETMCR);
161 /*
162 * Recommended by spec for cp14 accesses to ensure etmcr write is
163 * complete before polling etmsr
164 */
165 isb();
166 if (coresight_timeout_etm(drvdata, ETMSR, ETMSR_PROG_BIT, 1)) {
167 dev_err(&drvdata->csdev->dev,
168 "%s: timeout observed when probing at offset %#x\n",
169 __func__, ETMSR);
170 }
171 }
172
etm_clr_prog(struct etm_drvdata * drvdata)173 static void etm_clr_prog(struct etm_drvdata *drvdata)
174 {
175 u32 etmcr;
176
177 etmcr = etm_readl(drvdata, ETMCR);
178 etmcr &= ~ETMCR_ETM_PRG;
179 etm_writel(drvdata, etmcr, ETMCR);
180 /*
181 * Recommended by spec for cp14 accesses to ensure etmcr write is
182 * complete before polling etmsr
183 */
184 isb();
185 if (coresight_timeout_etm(drvdata, ETMSR, ETMSR_PROG_BIT, 0)) {
186 dev_err(&drvdata->csdev->dev,
187 "%s: timeout observed when probing at offset %#x\n",
188 __func__, ETMSR);
189 }
190 }
191
etm_set_default(struct etm_config * config)192 void etm_set_default(struct etm_config *config)
193 {
194 int i;
195
196 if (WARN_ON_ONCE(!config))
197 return;
198
199 /*
200 * Taken verbatim from the TRM:
201 *
202 * To trace all memory:
203 * set bit [24] in register 0x009, the ETMTECR1, to 1
204 * set all other bits in register 0x009, the ETMTECR1, to 0
205 * set all bits in register 0x007, the ETMTECR2, to 0
206 * set register 0x008, the ETMTEEVR, to 0x6F (TRUE).
207 */
208 config->enable_ctrl1 = ETMTECR1_INC_EXC;
209 config->enable_ctrl2 = 0x0;
210 config->enable_event = ETM_HARD_WIRE_RES_A;
211
212 config->trigger_event = ETM_DEFAULT_EVENT_VAL;
213 config->enable_event = ETM_HARD_WIRE_RES_A;
214
215 config->seq_12_event = ETM_DEFAULT_EVENT_VAL;
216 config->seq_21_event = ETM_DEFAULT_EVENT_VAL;
217 config->seq_23_event = ETM_DEFAULT_EVENT_VAL;
218 config->seq_31_event = ETM_DEFAULT_EVENT_VAL;
219 config->seq_32_event = ETM_DEFAULT_EVENT_VAL;
220 config->seq_13_event = ETM_DEFAULT_EVENT_VAL;
221 config->timestamp_event = ETM_DEFAULT_EVENT_VAL;
222
223 for (i = 0; i < ETM_MAX_CNTR; i++) {
224 config->cntr_rld_val[i] = 0x0;
225 config->cntr_event[i] = ETM_DEFAULT_EVENT_VAL;
226 config->cntr_rld_event[i] = ETM_DEFAULT_EVENT_VAL;
227 config->cntr_val[i] = 0x0;
228 }
229
230 config->seq_curr_state = 0x0;
231 config->ctxid_idx = 0x0;
232 for (i = 0; i < ETM_MAX_CTXID_CMP; i++)
233 config->ctxid_pid[i] = 0x0;
234
235 config->ctxid_mask = 0x0;
236 /* Setting default to 1024 as per TRM recommendation */
237 config->sync_freq = 0x400;
238 }
239
etm_config_trace_mode(struct etm_config * config)240 void etm_config_trace_mode(struct etm_config *config)
241 {
242 u32 flags, mode;
243
244 mode = config->mode;
245
246 mode &= (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER);
247
248 /* excluding kernel AND user space doesn't make sense */
249 if (mode == (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER))
250 return;
251
252 /* nothing to do if neither flags are set */
253 if (!(mode & ETM_MODE_EXCL_KERN) && !(mode & ETM_MODE_EXCL_USER))
254 return;
255
256 flags = (1 << 0 | /* instruction execute */
257 3 << 3 | /* ARM instruction */
258 0 << 5 | /* No data value comparison */
259 0 << 7 | /* No exact mach */
260 0 << 8); /* Ignore context ID */
261
262 /* No need to worry about single address comparators. */
263 config->enable_ctrl2 = 0x0;
264
265 /* Bit 0 is address range comparator 1 */
266 config->enable_ctrl1 = ETMTECR1_ADDR_COMP_1;
267
268 /*
269 * On ETMv3.5:
270 * ETMACTRn[13,11] == Non-secure state comparison control
271 * ETMACTRn[12,10] == Secure state comparison control
272 *
273 * b00 == Match in all modes in this state
274 * b01 == Do not match in any more in this state
275 * b10 == Match in all modes excepts user mode in this state
276 * b11 == Match only in user mode in this state
277 */
278
279 /* Tracing in secure mode is not supported at this time */
280 flags |= (0 << 12 | 1 << 10);
281
282 if (mode & ETM_MODE_EXCL_USER) {
283 /* exclude user, match all modes except user mode */
284 flags |= (1 << 13 | 0 << 11);
285 } else {
286 /* exclude kernel, match only in user mode */
287 flags |= (1 << 13 | 1 << 11);
288 }
289
290 /*
291 * The ETMEEVR register is already set to "hard wire A". As such
292 * all there is to do is setup an address comparator that spans
293 * the entire address range and configure the state and mode bits.
294 */
295 config->addr_val[0] = (u32) 0x0;
296 config->addr_val[1] = (u32) ~0x0;
297 config->addr_acctype[0] = flags;
298 config->addr_acctype[1] = flags;
299 config->addr_type[0] = ETM_ADDR_TYPE_RANGE;
300 config->addr_type[1] = ETM_ADDR_TYPE_RANGE;
301 }
302
303 #define ETM3X_SUPPORTED_OPTIONS (ETMCR_CYC_ACC | \
304 ETMCR_TIMESTAMP_EN | \
305 ETMCR_RETURN_STACK)
306
etm_parse_event_config(struct etm_drvdata * drvdata,struct perf_event * event)307 static int etm_parse_event_config(struct etm_drvdata *drvdata,
308 struct perf_event *event)
309 {
310 struct etm_config *config = &drvdata->config;
311 struct perf_event_attr *attr = &event->attr;
312
313 if (!attr)
314 return -EINVAL;
315
316 /* Clear configuration from previous run */
317 memset(config, 0, sizeof(struct etm_config));
318
319 if (attr->exclude_kernel)
320 config->mode = ETM_MODE_EXCL_KERN;
321
322 if (attr->exclude_user)
323 config->mode = ETM_MODE_EXCL_USER;
324
325 /* Always start from the default config */
326 etm_set_default(config);
327
328 /*
329 * By default the tracers are configured to trace the whole address
330 * range. Narrow the field only if requested by user space.
331 */
332 if (config->mode)
333 etm_config_trace_mode(config);
334
335 /*
336 * At this time only cycle accurate, return stack and timestamp
337 * options are available.
338 */
339 if (attr->config & ~ETM3X_SUPPORTED_OPTIONS)
340 return -EINVAL;
341
342 config->ctrl = attr->config;
343
344 /* Don't trace contextID when runs in non-root PID namespace */
345 if (!task_is_in_init_pid_ns(current))
346 config->ctrl &= ~ETMCR_CTXID_SIZE;
347
348 /*
349 * Possible to have cores with PTM (supports ret stack) and ETM
350 * (never has ret stack) on the same SoC. So if we have a request
351 * for return stack that can't be honoured on this core then
352 * clear the bit - trace will still continue normally
353 */
354 if ((config->ctrl & ETMCR_RETURN_STACK) &&
355 !(drvdata->etmccer & ETMCCER_RETSTACK))
356 config->ctrl &= ~ETMCR_RETURN_STACK;
357
358 return 0;
359 }
360
etm_enable_hw(struct etm_drvdata * drvdata)361 static int etm_enable_hw(struct etm_drvdata *drvdata)
362 {
363 int i, rc;
364 u32 etmcr;
365 struct etm_config *config = &drvdata->config;
366 struct coresight_device *csdev = drvdata->csdev;
367
368 CS_UNLOCK(drvdata->base);
369
370 rc = coresight_claim_device_unlocked(csdev);
371 if (rc)
372 goto done;
373
374 /* Turn engine on */
375 etm_clr_pwrdwn(drvdata);
376 /* Apply power to trace registers */
377 etm_set_pwrup(drvdata);
378 /* Make sure all registers are accessible */
379 etm_os_unlock(drvdata);
380
381 etm_set_prog(drvdata);
382
383 etmcr = etm_readl(drvdata, ETMCR);
384 /* Clear setting from a previous run if need be */
385 etmcr &= ~ETM3X_SUPPORTED_OPTIONS;
386 etmcr |= drvdata->port_size;
387 etmcr |= ETMCR_ETM_EN;
388 etm_writel(drvdata, config->ctrl | etmcr, ETMCR);
389 etm_writel(drvdata, config->trigger_event, ETMTRIGGER);
390 etm_writel(drvdata, config->startstop_ctrl, ETMTSSCR);
391 etm_writel(drvdata, config->enable_event, ETMTEEVR);
392 etm_writel(drvdata, config->enable_ctrl1, ETMTECR1);
393 etm_writel(drvdata, config->fifofull_level, ETMFFLR);
394 for (i = 0; i < drvdata->nr_addr_cmp; i++) {
395 etm_writel(drvdata, config->addr_val[i], ETMACVRn(i));
396 etm_writel(drvdata, config->addr_acctype[i], ETMACTRn(i));
397 }
398 for (i = 0; i < drvdata->nr_cntr; i++) {
399 etm_writel(drvdata, config->cntr_rld_val[i], ETMCNTRLDVRn(i));
400 etm_writel(drvdata, config->cntr_event[i], ETMCNTENRn(i));
401 etm_writel(drvdata, config->cntr_rld_event[i],
402 ETMCNTRLDEVRn(i));
403 etm_writel(drvdata, config->cntr_val[i], ETMCNTVRn(i));
404 }
405 etm_writel(drvdata, config->seq_12_event, ETMSQ12EVR);
406 etm_writel(drvdata, config->seq_21_event, ETMSQ21EVR);
407 etm_writel(drvdata, config->seq_23_event, ETMSQ23EVR);
408 etm_writel(drvdata, config->seq_31_event, ETMSQ31EVR);
409 etm_writel(drvdata, config->seq_32_event, ETMSQ32EVR);
410 etm_writel(drvdata, config->seq_13_event, ETMSQ13EVR);
411 etm_writel(drvdata, config->seq_curr_state, ETMSQR);
412 for (i = 0; i < drvdata->nr_ext_out; i++)
413 etm_writel(drvdata, ETM_DEFAULT_EVENT_VAL, ETMEXTOUTEVRn(i));
414 for (i = 0; i < drvdata->nr_ctxid_cmp; i++)
415 etm_writel(drvdata, config->ctxid_pid[i], ETMCIDCVRn(i));
416 etm_writel(drvdata, config->ctxid_mask, ETMCIDCMR);
417 etm_writel(drvdata, config->sync_freq, ETMSYNCFR);
418 /* No external input selected */
419 etm_writel(drvdata, 0x0, ETMEXTINSELR);
420 etm_writel(drvdata, config->timestamp_event, ETMTSEVR);
421 /* No auxiliary control selected */
422 etm_writel(drvdata, 0x0, ETMAUXCR);
423 etm_writel(drvdata, drvdata->traceid, ETMTRACEIDR);
424 /* No VMID comparator value selected */
425 etm_writel(drvdata, 0x0, ETMVMIDCVR);
426
427 etm_clr_prog(drvdata);
428
429 done:
430 CS_LOCK(drvdata->base);
431
432 dev_dbg(&drvdata->csdev->dev, "cpu: %d enable smp call done: %d\n",
433 drvdata->cpu, rc);
434 return rc;
435 }
436
437 struct etm_enable_arg {
438 struct etm_drvdata *drvdata;
439 int rc;
440 };
441
etm_enable_hw_smp_call(void * info)442 static void etm_enable_hw_smp_call(void *info)
443 {
444 struct etm_enable_arg *arg = info;
445
446 if (WARN_ON(!arg))
447 return;
448 arg->rc = etm_enable_hw(arg->drvdata);
449 }
450
etm_cpu_id(struct coresight_device * csdev)451 static int etm_cpu_id(struct coresight_device *csdev)
452 {
453 struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
454
455 return drvdata->cpu;
456 }
457
etm_read_alloc_trace_id(struct etm_drvdata * drvdata)458 int etm_read_alloc_trace_id(struct etm_drvdata *drvdata)
459 {
460 int trace_id;
461
462 /*
463 * This will allocate a trace ID to the cpu,
464 * or return the one currently allocated.
465 *
466 * trace id function has its own lock
467 */
468 trace_id = coresight_trace_id_get_cpu_id(drvdata->cpu);
469 if (IS_VALID_CS_TRACE_ID(trace_id))
470 drvdata->traceid = (u8)trace_id;
471 else
472 dev_err(&drvdata->csdev->dev,
473 "Failed to allocate trace ID for %s on CPU%d\n",
474 dev_name(&drvdata->csdev->dev), drvdata->cpu);
475 return trace_id;
476 }
477
etm_release_trace_id(struct etm_drvdata * drvdata)478 void etm_release_trace_id(struct etm_drvdata *drvdata)
479 {
480 coresight_trace_id_put_cpu_id(drvdata->cpu);
481 }
482
etm_enable_perf(struct coresight_device * csdev,struct perf_event * event)483 static int etm_enable_perf(struct coresight_device *csdev,
484 struct perf_event *event)
485 {
486 struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
487 int trace_id;
488
489 if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id()))
490 return -EINVAL;
491
492 /* Configure the tracer based on the session's specifics */
493 etm_parse_event_config(drvdata, event);
494
495 /*
496 * perf allocates cpu ids as part of _setup_aux() - device needs to use
497 * the allocated ID. This reads the current version without allocation.
498 *
499 * This does not use the trace id lock to prevent lock_dep issues
500 * with perf locks - we know the ID cannot change until perf shuts down
501 * the session
502 */
503 trace_id = coresight_trace_id_read_cpu_id(drvdata->cpu);
504 if (!IS_VALID_CS_TRACE_ID(trace_id)) {
505 dev_err(&drvdata->csdev->dev, "Failed to set trace ID for %s on CPU%d\n",
506 dev_name(&drvdata->csdev->dev), drvdata->cpu);
507 return -EINVAL;
508 }
509 drvdata->traceid = (u8)trace_id;
510
511 /* And enable it */
512 return etm_enable_hw(drvdata);
513 }
514
etm_enable_sysfs(struct coresight_device * csdev)515 static int etm_enable_sysfs(struct coresight_device *csdev)
516 {
517 struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
518 struct etm_enable_arg arg = { };
519 int ret;
520
521 spin_lock(&drvdata->spinlock);
522
523 /* sysfs needs to allocate and set a trace ID */
524 ret = etm_read_alloc_trace_id(drvdata);
525 if (ret < 0)
526 goto unlock_enable_sysfs;
527
528 /*
529 * Configure the ETM only if the CPU is online. If it isn't online
530 * hw configuration will take place on the local CPU during bring up.
531 */
532 if (cpu_online(drvdata->cpu)) {
533 arg.drvdata = drvdata;
534 ret = smp_call_function_single(drvdata->cpu,
535 etm_enable_hw_smp_call, &arg, 1);
536 if (!ret)
537 ret = arg.rc;
538 if (!ret)
539 drvdata->sticky_enable = true;
540 } else {
541 ret = -ENODEV;
542 }
543
544 if (ret)
545 etm_release_trace_id(drvdata);
546
547 unlock_enable_sysfs:
548 spin_unlock(&drvdata->spinlock);
549
550 if (!ret)
551 dev_dbg(&csdev->dev, "ETM tracing enabled\n");
552 return ret;
553 }
554
etm_enable(struct coresight_device * csdev,struct perf_event * event,enum cs_mode mode)555 static int etm_enable(struct coresight_device *csdev, struct perf_event *event,
556 enum cs_mode mode)
557 {
558 int ret;
559 u32 val;
560 struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
561
562 val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, mode);
563
564 /* Someone is already using the tracer */
565 if (val)
566 return -EBUSY;
567
568 switch (mode) {
569 case CS_MODE_SYSFS:
570 ret = etm_enable_sysfs(csdev);
571 break;
572 case CS_MODE_PERF:
573 ret = etm_enable_perf(csdev, event);
574 break;
575 default:
576 ret = -EINVAL;
577 }
578
579 /* The tracer didn't start */
580 if (ret)
581 local_set(&drvdata->mode, CS_MODE_DISABLED);
582
583 return ret;
584 }
585
etm_disable_hw(void * info)586 static void etm_disable_hw(void *info)
587 {
588 int i;
589 struct etm_drvdata *drvdata = info;
590 struct etm_config *config = &drvdata->config;
591 struct coresight_device *csdev = drvdata->csdev;
592
593 CS_UNLOCK(drvdata->base);
594 etm_set_prog(drvdata);
595
596 /* Read back sequencer and counters for post trace analysis */
597 config->seq_curr_state = (etm_readl(drvdata, ETMSQR) & ETM_SQR_MASK);
598
599 for (i = 0; i < drvdata->nr_cntr; i++)
600 config->cntr_val[i] = etm_readl(drvdata, ETMCNTVRn(i));
601
602 etm_set_pwrdwn(drvdata);
603 coresight_disclaim_device_unlocked(csdev);
604
605 CS_LOCK(drvdata->base);
606
607 dev_dbg(&drvdata->csdev->dev,
608 "cpu: %d disable smp call done\n", drvdata->cpu);
609 }
610
etm_disable_perf(struct coresight_device * csdev)611 static void etm_disable_perf(struct coresight_device *csdev)
612 {
613 struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
614
615 if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id()))
616 return;
617
618 CS_UNLOCK(drvdata->base);
619
620 /* Setting the prog bit disables tracing immediately */
621 etm_set_prog(drvdata);
622
623 /*
624 * There is no way to know when the tracer will be used again so
625 * power down the tracer.
626 */
627 etm_set_pwrdwn(drvdata);
628 coresight_disclaim_device_unlocked(csdev);
629
630 CS_LOCK(drvdata->base);
631
632 /*
633 * perf will release trace ids when _free_aux()
634 * is called at the end of the session
635 */
636
637 }
638
etm_disable_sysfs(struct coresight_device * csdev)639 static void etm_disable_sysfs(struct coresight_device *csdev)
640 {
641 struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
642
643 /*
644 * Taking hotplug lock here protects from clocks getting disabled
645 * with tracing being left on (crash scenario) if user disable occurs
646 * after cpu online mask indicates the cpu is offline but before the
647 * DYING hotplug callback is serviced by the ETM driver.
648 */
649 cpus_read_lock();
650 spin_lock(&drvdata->spinlock);
651
652 /*
653 * Executing etm_disable_hw on the cpu whose ETM is being disabled
654 * ensures that register writes occur when cpu is powered.
655 */
656 smp_call_function_single(drvdata->cpu, etm_disable_hw, drvdata, 1);
657
658 spin_unlock(&drvdata->spinlock);
659 cpus_read_unlock();
660
661 /*
662 * we only release trace IDs when resetting sysfs.
663 * This permits sysfs users to read the trace ID after the trace
664 * session has completed. This maintains operational behaviour with
665 * prior trace id allocation method
666 */
667
668 dev_dbg(&csdev->dev, "ETM tracing disabled\n");
669 }
670
etm_disable(struct coresight_device * csdev,struct perf_event * event)671 static void etm_disable(struct coresight_device *csdev,
672 struct perf_event *event)
673 {
674 enum cs_mode mode;
675 struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
676
677 /*
678 * For as long as the tracer isn't disabled another entity can't
679 * change its status. As such we can read the status here without
680 * fearing it will change under us.
681 */
682 mode = local_read(&drvdata->mode);
683
684 switch (mode) {
685 case CS_MODE_DISABLED:
686 break;
687 case CS_MODE_SYSFS:
688 etm_disable_sysfs(csdev);
689 break;
690 case CS_MODE_PERF:
691 etm_disable_perf(csdev);
692 break;
693 default:
694 WARN_ON_ONCE(mode);
695 return;
696 }
697
698 if (mode)
699 local_set(&drvdata->mode, CS_MODE_DISABLED);
700 }
701
702 static const struct coresight_ops_source etm_source_ops = {
703 .cpu_id = etm_cpu_id,
704 .enable = etm_enable,
705 .disable = etm_disable,
706 };
707
708 static const struct coresight_ops etm_cs_ops = {
709 .source_ops = &etm_source_ops,
710 };
711
etm_online_cpu(unsigned int cpu)712 static int etm_online_cpu(unsigned int cpu)
713 {
714 if (!etmdrvdata[cpu])
715 return 0;
716
717 if (etmdrvdata[cpu]->boot_enable && !etmdrvdata[cpu]->sticky_enable)
718 coresight_enable(etmdrvdata[cpu]->csdev);
719 return 0;
720 }
721
etm_starting_cpu(unsigned int cpu)722 static int etm_starting_cpu(unsigned int cpu)
723 {
724 if (!etmdrvdata[cpu])
725 return 0;
726
727 spin_lock(&etmdrvdata[cpu]->spinlock);
728 if (!etmdrvdata[cpu]->os_unlock) {
729 etm_os_unlock(etmdrvdata[cpu]);
730 etmdrvdata[cpu]->os_unlock = true;
731 }
732
733 if (local_read(&etmdrvdata[cpu]->mode))
734 etm_enable_hw(etmdrvdata[cpu]);
735 spin_unlock(&etmdrvdata[cpu]->spinlock);
736 return 0;
737 }
738
etm_dying_cpu(unsigned int cpu)739 static int etm_dying_cpu(unsigned int cpu)
740 {
741 if (!etmdrvdata[cpu])
742 return 0;
743
744 spin_lock(&etmdrvdata[cpu]->spinlock);
745 if (local_read(&etmdrvdata[cpu]->mode))
746 etm_disable_hw(etmdrvdata[cpu]);
747 spin_unlock(&etmdrvdata[cpu]->spinlock);
748 return 0;
749 }
750
etm_arch_supported(u8 arch)751 static bool etm_arch_supported(u8 arch)
752 {
753 switch (arch) {
754 case ETM_ARCH_V3_3:
755 break;
756 case ETM_ARCH_V3_5:
757 break;
758 case PFT_ARCH_V1_0:
759 break;
760 case PFT_ARCH_V1_1:
761 break;
762 default:
763 return false;
764 }
765 return true;
766 }
767
etm_init_arch_data(void * info)768 static void etm_init_arch_data(void *info)
769 {
770 u32 etmidr;
771 u32 etmccr;
772 struct etm_drvdata *drvdata = info;
773
774 /* Make sure all registers are accessible */
775 etm_os_unlock(drvdata);
776
777 CS_UNLOCK(drvdata->base);
778
779 /* First dummy read */
780 (void)etm_readl(drvdata, ETMPDSR);
781 /* Provide power to ETM: ETMPDCR[3] == 1 */
782 etm_set_pwrup(drvdata);
783 /*
784 * Clear power down bit since when this bit is set writes to
785 * certain registers might be ignored.
786 */
787 etm_clr_pwrdwn(drvdata);
788 /*
789 * Set prog bit. It will be set from reset but this is included to
790 * ensure it is set
791 */
792 etm_set_prog(drvdata);
793
794 /* Find all capabilities */
795 etmidr = etm_readl(drvdata, ETMIDR);
796 drvdata->arch = BMVAL(etmidr, 4, 11);
797 drvdata->port_size = etm_readl(drvdata, ETMCR) & PORT_SIZE_MASK;
798
799 drvdata->etmccer = etm_readl(drvdata, ETMCCER);
800 etmccr = etm_readl(drvdata, ETMCCR);
801 drvdata->etmccr = etmccr;
802 drvdata->nr_addr_cmp = BMVAL(etmccr, 0, 3) * 2;
803 drvdata->nr_cntr = BMVAL(etmccr, 13, 15);
804 drvdata->nr_ext_inp = BMVAL(etmccr, 17, 19);
805 drvdata->nr_ext_out = BMVAL(etmccr, 20, 22);
806 drvdata->nr_ctxid_cmp = BMVAL(etmccr, 24, 25);
807
808 etm_set_pwrdwn(drvdata);
809 etm_clr_pwrup(drvdata);
810 CS_LOCK(drvdata->base);
811 }
812
etm_hp_setup(void)813 static int __init etm_hp_setup(void)
814 {
815 int ret;
816
817 ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING,
818 "arm/coresight:starting",
819 etm_starting_cpu, etm_dying_cpu);
820
821 if (ret)
822 return ret;
823
824 ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
825 "arm/coresight:online",
826 etm_online_cpu, NULL);
827
828 /* HP dyn state ID returned in ret on success */
829 if (ret > 0) {
830 hp_online = ret;
831 return 0;
832 }
833
834 /* failed dyn state - remove others */
835 cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
836
837 return ret;
838 }
839
etm_hp_clear(void)840 static void etm_hp_clear(void)
841 {
842 cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
843 if (hp_online) {
844 cpuhp_remove_state_nocalls(hp_online);
845 hp_online = 0;
846 }
847 }
848
etm_probe(struct amba_device * adev,const struct amba_id * id)849 static int etm_probe(struct amba_device *adev, const struct amba_id *id)
850 {
851 int ret;
852 void __iomem *base;
853 struct device *dev = &adev->dev;
854 struct coresight_platform_data *pdata = NULL;
855 struct etm_drvdata *drvdata;
856 struct resource *res = &adev->res;
857 struct coresight_desc desc = { 0 };
858
859 drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
860 if (!drvdata)
861 return -ENOMEM;
862
863 drvdata->use_cp14 = fwnode_property_read_bool(dev->fwnode, "arm,cp14");
864 dev_set_drvdata(dev, drvdata);
865
866 /* Validity for the resource is already checked by the AMBA core */
867 base = devm_ioremap_resource(dev, res);
868 if (IS_ERR(base))
869 return PTR_ERR(base);
870
871 drvdata->base = base;
872 desc.access = CSDEV_ACCESS_IOMEM(base);
873
874 spin_lock_init(&drvdata->spinlock);
875
876 drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
877 if (!IS_ERR(drvdata->atclk)) {
878 ret = clk_prepare_enable(drvdata->atclk);
879 if (ret)
880 return ret;
881 }
882
883 drvdata->cpu = coresight_get_cpu(dev);
884 if (drvdata->cpu < 0)
885 return drvdata->cpu;
886
887 desc.name = devm_kasprintf(dev, GFP_KERNEL, "etm%d", drvdata->cpu);
888 if (!desc.name)
889 return -ENOMEM;
890
891 if (smp_call_function_single(drvdata->cpu,
892 etm_init_arch_data, drvdata, 1))
893 dev_err(dev, "ETM arch init failed\n");
894
895 if (etm_arch_supported(drvdata->arch) == false)
896 return -EINVAL;
897
898 etm_set_default(&drvdata->config);
899
900 pdata = coresight_get_platform_data(dev);
901 if (IS_ERR(pdata))
902 return PTR_ERR(pdata);
903
904 adev->dev.platform_data = pdata;
905
906 desc.type = CORESIGHT_DEV_TYPE_SOURCE;
907 desc.subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_PROC;
908 desc.ops = &etm_cs_ops;
909 desc.pdata = pdata;
910 desc.dev = dev;
911 desc.groups = coresight_etm_groups;
912 drvdata->csdev = coresight_register(&desc);
913 if (IS_ERR(drvdata->csdev))
914 return PTR_ERR(drvdata->csdev);
915
916 ret = etm_perf_symlink(drvdata->csdev, true);
917 if (ret) {
918 coresight_unregister(drvdata->csdev);
919 return ret;
920 }
921
922 etmdrvdata[drvdata->cpu] = drvdata;
923
924 pm_runtime_put(&adev->dev);
925 dev_info(&drvdata->csdev->dev,
926 "%s initialized\n", (char *)coresight_get_uci_data(id));
927 if (boot_enable) {
928 coresight_enable(drvdata->csdev);
929 drvdata->boot_enable = true;
930 }
931
932 return 0;
933 }
934
clear_etmdrvdata(void * info)935 static void clear_etmdrvdata(void *info)
936 {
937 int cpu = *(int *)info;
938
939 etmdrvdata[cpu] = NULL;
940 }
941
etm_remove(struct amba_device * adev)942 static void etm_remove(struct amba_device *adev)
943 {
944 struct etm_drvdata *drvdata = dev_get_drvdata(&adev->dev);
945
946 etm_perf_symlink(drvdata->csdev, false);
947
948 /*
949 * Taking hotplug lock here to avoid racing between etm_remove and
950 * CPU hotplug call backs.
951 */
952 cpus_read_lock();
953 /*
954 * The readers for etmdrvdata[] are CPU hotplug call backs
955 * and PM notification call backs. Change etmdrvdata[i] on
956 * CPU i ensures these call backs has consistent view
957 * inside one call back function.
958 */
959 if (smp_call_function_single(drvdata->cpu, clear_etmdrvdata, &drvdata->cpu, 1))
960 etmdrvdata[drvdata->cpu] = NULL;
961
962 cpus_read_unlock();
963
964 coresight_unregister(drvdata->csdev);
965 }
966
967 #ifdef CONFIG_PM
etm_runtime_suspend(struct device * dev)968 static int etm_runtime_suspend(struct device *dev)
969 {
970 struct etm_drvdata *drvdata = dev_get_drvdata(dev);
971
972 if (drvdata && !IS_ERR(drvdata->atclk))
973 clk_disable_unprepare(drvdata->atclk);
974
975 return 0;
976 }
977
etm_runtime_resume(struct device * dev)978 static int etm_runtime_resume(struct device *dev)
979 {
980 struct etm_drvdata *drvdata = dev_get_drvdata(dev);
981
982 if (drvdata && !IS_ERR(drvdata->atclk))
983 clk_prepare_enable(drvdata->atclk);
984
985 return 0;
986 }
987 #endif
988
989 static const struct dev_pm_ops etm_dev_pm_ops = {
990 SET_RUNTIME_PM_OPS(etm_runtime_suspend, etm_runtime_resume, NULL)
991 };
992
993 static const struct amba_id etm_ids[] = {
994 /* ETM 3.3 */
995 CS_AMBA_ID_DATA(0x000bb921, "ETM 3.3"),
996 /* ETM 3.5 - Cortex-A5 */
997 CS_AMBA_ID_DATA(0x000bb955, "ETM 3.5"),
998 /* ETM 3.5 */
999 CS_AMBA_ID_DATA(0x000bb956, "ETM 3.5"),
1000 /* PTM 1.0 */
1001 CS_AMBA_ID_DATA(0x000bb950, "PTM 1.0"),
1002 /* PTM 1.1 */
1003 CS_AMBA_ID_DATA(0x000bb95f, "PTM 1.1"),
1004 /* PTM 1.1 Qualcomm */
1005 CS_AMBA_ID_DATA(0x000b006f, "PTM 1.1"),
1006 { 0, 0},
1007 };
1008
1009 MODULE_DEVICE_TABLE(amba, etm_ids);
1010
1011 static struct amba_driver etm_driver = {
1012 .drv = {
1013 .name = "coresight-etm3x",
1014 .owner = THIS_MODULE,
1015 .pm = &etm_dev_pm_ops,
1016 .suppress_bind_attrs = true,
1017 },
1018 .probe = etm_probe,
1019 .remove = etm_remove,
1020 .id_table = etm_ids,
1021 };
1022
etm_init(void)1023 static int __init etm_init(void)
1024 {
1025 int ret;
1026
1027 ret = etm_hp_setup();
1028
1029 /* etm_hp_setup() does its own cleanup - exit on error */
1030 if (ret)
1031 return ret;
1032
1033 ret = amba_driver_register(&etm_driver);
1034 if (ret) {
1035 pr_err("Error registering etm3x driver\n");
1036 etm_hp_clear();
1037 }
1038
1039 return ret;
1040 }
1041
etm_exit(void)1042 static void __exit etm_exit(void)
1043 {
1044 amba_driver_unregister(&etm_driver);
1045 etm_hp_clear();
1046 }
1047
1048 module_init(etm_init);
1049 module_exit(etm_exit);
1050
1051 MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
1052 MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
1053 MODULE_DESCRIPTION("Arm CoreSight Program Flow Trace driver");
1054 MODULE_LICENSE("GPL v2");
1055