• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2014, The Linux Foundation. All rights reserved.
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/moduleparam.h>
8 #include <linux/init.h>
9 #include <linux/types.h>
10 #include <linux/device.h>
11 #include <linux/io.h>
12 #include <linux/err.h>
13 #include <linux/fs.h>
14 #include <linux/slab.h>
15 #include <linux/delay.h>
16 #include <linux/smp.h>
17 #include <linux/sysfs.h>
18 #include <linux/stat.h>
19 #include <linux/clk.h>
20 #include <linux/cpu.h>
21 #include <linux/cpu_pm.h>
22 #include <linux/coresight.h>
23 #include <linux/coresight-pmu.h>
24 #include <linux/pm_wakeup.h>
25 #include <linux/amba/bus.h>
26 #include <linux/seq_file.h>
27 #include <linux/uaccess.h>
28 #include <linux/perf_event.h>
29 #include <linux/pm_runtime.h>
30 #include <linux/property.h>
31 #include <asm/sections.h>
32 #include <asm/local.h>
33 #include <asm/virt.h>
34 
35 #include "coresight-etm4x.h"
36 #include "coresight-etm-perf.h"
37 
38 static int boot_enable;
39 module_param(boot_enable, int, 0444);
40 MODULE_PARM_DESC(boot_enable, "Enable tracing on boot");
41 
42 #define PARAM_PM_SAVE_FIRMWARE	  0 /* save self-hosted state as per firmware */
43 #define PARAM_PM_SAVE_NEVER	  1 /* never save any state */
44 #define PARAM_PM_SAVE_SELF_HOSTED 2 /* save self-hosted state only */
45 
46 static int pm_save_enable = PARAM_PM_SAVE_FIRMWARE;
47 module_param(pm_save_enable, int, 0444);
48 MODULE_PARM_DESC(pm_save_enable,
49 	"Save/restore state on power down: 1 = never, 2 = self-hosted");
50 
51 static struct etmv4_drvdata *etmdrvdata[NR_CPUS];
52 static void etm4_set_default_config(struct etmv4_config *config);
53 static int etm4_set_event_filters(struct etmv4_drvdata *drvdata,
54 				  struct perf_event *event);
55 static u64 etm4_get_access_type(struct etmv4_config *config);
56 
57 static enum cpuhp_state hp_online;
58 
etm4_os_unlock(struct etmv4_drvdata * drvdata)59 static void etm4_os_unlock(struct etmv4_drvdata *drvdata)
60 {
61 	/* Writing 0 to TRCOSLAR unlocks the trace registers */
62 	writel_relaxed(0x0, drvdata->base + TRCOSLAR);
63 	drvdata->os_unlock = true;
64 	isb();
65 }
66 
etm4_os_lock(struct etmv4_drvdata * drvdata)67 static void etm4_os_lock(struct etmv4_drvdata *drvdata)
68 {
69 	/* Writing 0x1 to TRCOSLAR locks the trace registers */
70 	writel_relaxed(0x1, drvdata->base + TRCOSLAR);
71 	drvdata->os_unlock = false;
72 	isb();
73 }
74 
etm4_arch_supported(u8 arch)75 static bool etm4_arch_supported(u8 arch)
76 {
77 	/* Mask out the minor version number */
78 	switch (arch & 0xf0) {
79 	case ETM_ARCH_V4:
80 		break;
81 	default:
82 		return false;
83 	}
84 	return true;
85 }
86 
etm4_cpu_id(struct coresight_device * csdev)87 static int etm4_cpu_id(struct coresight_device *csdev)
88 {
89 	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
90 
91 	return drvdata->cpu;
92 }
93 
etm4_trace_id(struct coresight_device * csdev)94 static int etm4_trace_id(struct coresight_device *csdev)
95 {
96 	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
97 
98 	return drvdata->trcid;
99 }
100 
101 struct etm4_enable_arg {
102 	struct etmv4_drvdata *drvdata;
103 	int rc;
104 };
105 
etm4_enable_hw(struct etmv4_drvdata * drvdata)106 static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
107 {
108 	int i, rc;
109 	struct etmv4_config *config = &drvdata->config;
110 	struct device *etm_dev = &drvdata->csdev->dev;
111 
112 	CS_UNLOCK(drvdata->base);
113 
114 	etm4_os_unlock(drvdata);
115 
116 	rc = coresight_claim_device_unlocked(drvdata->base);
117 	if (rc)
118 		goto done;
119 
120 	/* Disable the trace unit before programming trace registers */
121 	writel_relaxed(0, drvdata->base + TRCPRGCTLR);
122 
123 	/* wait for TRCSTATR.IDLE to go up */
124 	if (coresight_timeout(drvdata->base, TRCSTATR, TRCSTATR_IDLE_BIT, 1))
125 		dev_err(etm_dev,
126 			"timeout while waiting for Idle Trace Status\n");
127 	if (drvdata->nr_pe)
128 		writel_relaxed(config->pe_sel, drvdata->base + TRCPROCSELR);
129 	writel_relaxed(config->cfg, drvdata->base + TRCCONFIGR);
130 	/* nothing specific implemented */
131 	writel_relaxed(0x0, drvdata->base + TRCAUXCTLR);
132 	writel_relaxed(config->eventctrl0, drvdata->base + TRCEVENTCTL0R);
133 	writel_relaxed(config->eventctrl1, drvdata->base + TRCEVENTCTL1R);
134 	if (drvdata->stallctl)
135 		writel_relaxed(config->stall_ctrl, drvdata->base + TRCSTALLCTLR);
136 	writel_relaxed(config->ts_ctrl, drvdata->base + TRCTSCTLR);
137 	writel_relaxed(config->syncfreq, drvdata->base + TRCSYNCPR);
138 	writel_relaxed(config->ccctlr, drvdata->base + TRCCCCTLR);
139 	writel_relaxed(config->bb_ctrl, drvdata->base + TRCBBCTLR);
140 	writel_relaxed(drvdata->trcid, drvdata->base + TRCTRACEIDR);
141 	writel_relaxed(config->vinst_ctrl, drvdata->base + TRCVICTLR);
142 	writel_relaxed(config->viiectlr, drvdata->base + TRCVIIECTLR);
143 	writel_relaxed(config->vissctlr,
144 		       drvdata->base + TRCVISSCTLR);
145 	if (drvdata->nr_pe_cmp)
146 		writel_relaxed(config->vipcssctlr,
147 			       drvdata->base + TRCVIPCSSCTLR);
148 	for (i = 0; i < drvdata->nrseqstate - 1; i++)
149 		writel_relaxed(config->seq_ctrl[i],
150 			       drvdata->base + TRCSEQEVRn(i));
151 	writel_relaxed(config->seq_rst, drvdata->base + TRCSEQRSTEVR);
152 	writel_relaxed(config->seq_state, drvdata->base + TRCSEQSTR);
153 	writel_relaxed(config->ext_inp, drvdata->base + TRCEXTINSELR);
154 	for (i = 0; i < drvdata->nr_cntr; i++) {
155 		writel_relaxed(config->cntrldvr[i],
156 			       drvdata->base + TRCCNTRLDVRn(i));
157 		writel_relaxed(config->cntr_ctrl[i],
158 			       drvdata->base + TRCCNTCTLRn(i));
159 		writel_relaxed(config->cntr_val[i],
160 			       drvdata->base + TRCCNTVRn(i));
161 	}
162 
163 	/*
164 	 * Resource selector pair 0 is always implemented and reserved.  As
165 	 * such start at 2.
166 	 */
167 	for (i = 2; i < drvdata->nr_resource * 2; i++)
168 		writel_relaxed(config->res_ctrl[i],
169 			       drvdata->base + TRCRSCTLRn(i));
170 
171 	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
172 		/* always clear status bit on restart if using single-shot */
173 		if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
174 			config->ss_status[i] &= ~BIT(31);
175 		writel_relaxed(config->ss_ctrl[i],
176 			       drvdata->base + TRCSSCCRn(i));
177 		writel_relaxed(config->ss_status[i],
178 			       drvdata->base + TRCSSCSRn(i));
179 		writel_relaxed(config->ss_pe_cmp[i],
180 			       drvdata->base + TRCSSPCICRn(i));
181 	}
182 	for (i = 0; i < drvdata->nr_addr_cmp; i++) {
183 		writeq_relaxed(config->addr_val[i],
184 			       drvdata->base + TRCACVRn(i));
185 		writeq_relaxed(config->addr_acc[i],
186 			       drvdata->base + TRCACATRn(i));
187 	}
188 	for (i = 0; i < drvdata->numcidc; i++)
189 		writeq_relaxed(config->ctxid_pid[i],
190 			       drvdata->base + TRCCIDCVRn(i));
191 	writel_relaxed(config->ctxid_mask0, drvdata->base + TRCCIDCCTLR0);
192 	if (drvdata->numcidc > 4)
193 		writel_relaxed(config->ctxid_mask1, drvdata->base + TRCCIDCCTLR1);
194 
195 	for (i = 0; i < drvdata->numvmidc; i++)
196 		writeq_relaxed(config->vmid_val[i],
197 			       drvdata->base + TRCVMIDCVRn(i));
198 	writel_relaxed(config->vmid_mask0, drvdata->base + TRCVMIDCCTLR0);
199 	if (drvdata->numvmidc > 4)
200 		writel_relaxed(config->vmid_mask1, drvdata->base + TRCVMIDCCTLR1);
201 
202 	if (!drvdata->skip_power_up) {
203 		/*
204 		 * Request to keep the trace unit powered and also
205 		 * emulation of powerdown
206 		 */
207 		writel_relaxed(readl_relaxed(drvdata->base + TRCPDCR) |
208 			       TRCPDCR_PU, drvdata->base + TRCPDCR);
209 	}
210 
211 	/* Enable the trace unit */
212 	writel_relaxed(1, drvdata->base + TRCPRGCTLR);
213 
214 	/* wait for TRCSTATR.IDLE to go back down to '0' */
215 	if (coresight_timeout(drvdata->base, TRCSTATR, TRCSTATR_IDLE_BIT, 0))
216 		dev_err(etm_dev,
217 			"timeout while waiting for Idle Trace Status\n");
218 
219 	/*
220 	 * As recommended by section 4.3.7 ("Synchronization when using the
221 	 * memory-mapped interface") of ARM IHI 0064D
222 	 */
223 	dsb(sy);
224 	isb();
225 
226 done:
227 	CS_LOCK(drvdata->base);
228 
229 	dev_dbg(etm_dev, "cpu: %d enable smp call done: %d\n",
230 		drvdata->cpu, rc);
231 	return rc;
232 }
233 
etm4_enable_hw_smp_call(void * info)234 static void etm4_enable_hw_smp_call(void *info)
235 {
236 	struct etm4_enable_arg *arg = info;
237 
238 	if (WARN_ON(!arg))
239 		return;
240 	arg->rc = etm4_enable_hw(arg->drvdata);
241 }
242 
243 /*
244  * The goal of function etm4_config_timestamp_event() is to configure a
245  * counter that will tell the tracer to emit a timestamp packet when it
246  * reaches zero.  This is done in order to get a more fine grained idea
247  * of when instructions are executed so that they can be correlated
248  * with execution on other CPUs.
249  *
250  * To do this the counter itself is configured to self reload and
251  * TRCRSCTLR1 (always true) used to get the counter to decrement.  From
252  * there a resource selector is configured with the counter and the
253  * timestamp control register to use the resource selector to trigger the
254  * event that will insert a timestamp packet in the stream.
255  */
etm4_config_timestamp_event(struct etmv4_drvdata * drvdata)256 static int etm4_config_timestamp_event(struct etmv4_drvdata *drvdata)
257 {
258 	int ctridx, ret = -EINVAL;
259 	int counter, rselector;
260 	u32 val = 0;
261 	struct etmv4_config *config = &drvdata->config;
262 
263 	/* No point in trying if we don't have at least one counter */
264 	if (!drvdata->nr_cntr)
265 		goto out;
266 
267 	/* Find a counter that hasn't been initialised */
268 	for (ctridx = 0; ctridx < drvdata->nr_cntr; ctridx++)
269 		if (config->cntr_val[ctridx] == 0)
270 			break;
271 
272 	/* All the counters have been configured already, bail out */
273 	if (ctridx == drvdata->nr_cntr) {
274 		pr_debug("%s: no available counter found\n", __func__);
275 		ret = -ENOSPC;
276 		goto out;
277 	}
278 
279 	/*
280 	 * Searching for an available resource selector to use, starting at
281 	 * '2' since every implementation has at least 2 resource selector.
282 	 * ETMIDR4 gives the number of resource selector _pairs_,
283 	 * hence multiply by 2.
284 	 */
285 	for (rselector = 2; rselector < drvdata->nr_resource * 2; rselector++)
286 		if (!config->res_ctrl[rselector])
287 			break;
288 
289 	if (rselector == drvdata->nr_resource * 2) {
290 		pr_debug("%s: no available resource selector found\n",
291 			 __func__);
292 		ret = -ENOSPC;
293 		goto out;
294 	}
295 
296 	/* Remember what counter we used */
297 	counter = 1 << ctridx;
298 
299 	/*
300 	 * Initialise original and reload counter value to the smallest
301 	 * possible value in order to get as much precision as we can.
302 	 */
303 	config->cntr_val[ctridx] = 1;
304 	config->cntrldvr[ctridx] = 1;
305 
306 	/* Set the trace counter control register */
307 	val =  0x1 << 16	|  /* Bit 16, reload counter automatically */
308 	       0x0 << 7		|  /* Select single resource selector */
309 	       0x1;		   /* Resource selector 1, i.e always true */
310 
311 	config->cntr_ctrl[ctridx] = val;
312 
313 	val = 0x2 << 16		| /* Group 0b0010 - Counter and sequencers */
314 	      counter << 0;	  /* Counter to use */
315 
316 	config->res_ctrl[rselector] = val;
317 
318 	val = 0x0 << 7		| /* Select single resource selector */
319 	      rselector;	  /* Resource selector */
320 
321 	config->ts_ctrl = val;
322 
323 	ret = 0;
324 out:
325 	return ret;
326 }
327 
etm4_parse_event_config(struct etmv4_drvdata * drvdata,struct perf_event * event)328 static int etm4_parse_event_config(struct etmv4_drvdata *drvdata,
329 				   struct perf_event *event)
330 {
331 	int ret = 0;
332 	struct etmv4_config *config = &drvdata->config;
333 	struct perf_event_attr *attr = &event->attr;
334 
335 	if (!attr) {
336 		ret = -EINVAL;
337 		goto out;
338 	}
339 
340 	/* Clear configuration from previous run */
341 	memset(config, 0, sizeof(struct etmv4_config));
342 
343 	if (attr->exclude_kernel)
344 		config->mode = ETM_MODE_EXCL_KERN;
345 
346 	if (attr->exclude_user)
347 		config->mode = ETM_MODE_EXCL_USER;
348 
349 	/* Always start from the default config */
350 	etm4_set_default_config(config);
351 
352 	/* Configure filters specified on the perf cmd line, if any. */
353 	ret = etm4_set_event_filters(drvdata, event);
354 	if (ret)
355 		goto out;
356 
357 	/* Go from generic option to ETMv4 specifics */
358 	if (attr->config & BIT(ETM_OPT_CYCACC)) {
359 		config->cfg |= BIT(4);
360 		/* TRM: Must program this for cycacc to work */
361 		config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT;
362 	}
363 	if (attr->config & BIT(ETM_OPT_TS)) {
364 		/*
365 		 * Configure timestamps to be emitted at regular intervals in
366 		 * order to correlate instructions executed on different CPUs
367 		 * (CPU-wide trace scenarios).
368 		 */
369 		ret = etm4_config_timestamp_event(drvdata);
370 
371 		/*
372 		 * No need to go further if timestamp intervals can't
373 		 * be configured.
374 		 */
375 		if (ret)
376 			goto out;
377 
378 		/* bit[11], Global timestamp tracing bit */
379 		config->cfg |= BIT(11);
380 	}
381 
382 	if (attr->config & BIT(ETM_OPT_CTXTID))
383 		/* bit[6], Context ID tracing bit */
384 		config->cfg |= BIT(ETM4_CFG_BIT_CTXTID);
385 
386 	/* return stack - enable if selected and supported */
387 	if ((attr->config & BIT(ETM_OPT_RETSTK)) && drvdata->retstack)
388 		/* bit[12], Return stack enable bit */
389 		config->cfg |= BIT(12);
390 
391 out:
392 	return ret;
393 }
394 
etm4_enable_perf(struct coresight_device * csdev,struct perf_event * event)395 static int etm4_enable_perf(struct coresight_device *csdev,
396 			    struct perf_event *event)
397 {
398 	int ret = 0;
399 	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
400 
401 	if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id())) {
402 		ret = -EINVAL;
403 		goto out;
404 	}
405 
406 	/* Configure the tracer based on the session's specifics */
407 	ret = etm4_parse_event_config(drvdata, event);
408 	if (ret)
409 		goto out;
410 	/* And enable it */
411 	ret = etm4_enable_hw(drvdata);
412 
413 out:
414 	return ret;
415 }
416 
etm4_enable_sysfs(struct coresight_device * csdev)417 static int etm4_enable_sysfs(struct coresight_device *csdev)
418 {
419 	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
420 	struct etm4_enable_arg arg = { };
421 	int ret;
422 
423 	spin_lock(&drvdata->spinlock);
424 
425 	/*
426 	 * Executing etm4_enable_hw on the cpu whose ETM is being enabled
427 	 * ensures that register writes occur when cpu is powered.
428 	 */
429 	arg.drvdata = drvdata;
430 	ret = smp_call_function_single(drvdata->cpu,
431 				       etm4_enable_hw_smp_call, &arg, 1);
432 	if (!ret)
433 		ret = arg.rc;
434 	if (!ret)
435 		drvdata->sticky_enable = true;
436 	spin_unlock(&drvdata->spinlock);
437 
438 	if (!ret)
439 		dev_dbg(&csdev->dev, "ETM tracing enabled\n");
440 	return ret;
441 }
442 
etm4_enable(struct coresight_device * csdev,struct perf_event * event,u32 mode)443 static int etm4_enable(struct coresight_device *csdev,
444 		       struct perf_event *event, u32 mode)
445 {
446 	int ret;
447 	u32 val;
448 	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
449 
450 	val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, mode);
451 
452 	/* Someone is already using the tracer */
453 	if (val)
454 		return -EBUSY;
455 
456 	switch (mode) {
457 	case CS_MODE_SYSFS:
458 		ret = etm4_enable_sysfs(csdev);
459 		break;
460 	case CS_MODE_PERF:
461 		ret = etm4_enable_perf(csdev, event);
462 		break;
463 	default:
464 		ret = -EINVAL;
465 	}
466 
467 	/* The tracer didn't start */
468 	if (ret)
469 		local_set(&drvdata->mode, CS_MODE_DISABLED);
470 
471 	return ret;
472 }
473 
etm4_disable_hw(void * info)474 static void etm4_disable_hw(void *info)
475 {
476 	u32 control;
477 	struct etmv4_drvdata *drvdata = info;
478 	struct etmv4_config *config = &drvdata->config;
479 	struct device *etm_dev = &drvdata->csdev->dev;
480 	int i;
481 
482 	CS_UNLOCK(drvdata->base);
483 
484 	if (!drvdata->skip_power_up) {
485 		/* power can be removed from the trace unit now */
486 		control = readl_relaxed(drvdata->base + TRCPDCR);
487 		control &= ~TRCPDCR_PU;
488 		writel_relaxed(control, drvdata->base + TRCPDCR);
489 	}
490 
491 	control = readl_relaxed(drvdata->base + TRCPRGCTLR);
492 
493 	/* EN, bit[0] Trace unit enable bit */
494 	control &= ~0x1;
495 
496 	/*
497 	 * Make sure everything completes before disabling, as recommended
498 	 * by section 7.3.77 ("TRCVICTLR, ViewInst Main Control Register,
499 	 * SSTATUS") of ARM IHI 0064D
500 	 */
501 	dsb(sy);
502 	isb();
503 	writel_relaxed(control, drvdata->base + TRCPRGCTLR);
504 
505 	/* wait for TRCSTATR.PMSTABLE to go to '1' */
506 	if (coresight_timeout(drvdata->base, TRCSTATR,
507 			      TRCSTATR_PMSTABLE_BIT, 1))
508 		dev_err(etm_dev,
509 			"timeout while waiting for PM stable Trace Status\n");
510 
511 	/* read the status of the single shot comparators */
512 	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
513 		config->ss_status[i] =
514 			readl_relaxed(drvdata->base + TRCSSCSRn(i));
515 	}
516 
517 	/* read back the current counter values */
518 	for (i = 0; i < drvdata->nr_cntr; i++) {
519 		config->cntr_val[i] =
520 			readl_relaxed(drvdata->base + TRCCNTVRn(i));
521 	}
522 
523 	coresight_disclaim_device_unlocked(drvdata->base);
524 
525 	CS_LOCK(drvdata->base);
526 
527 	dev_dbg(&drvdata->csdev->dev,
528 		"cpu: %d disable smp call done\n", drvdata->cpu);
529 }
530 
etm4_disable_perf(struct coresight_device * csdev,struct perf_event * event)531 static int etm4_disable_perf(struct coresight_device *csdev,
532 			     struct perf_event *event)
533 {
534 	u32 control;
535 	struct etm_filters *filters = event->hw.addr_filters;
536 	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
537 
538 	if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id()))
539 		return -EINVAL;
540 
541 	etm4_disable_hw(drvdata);
542 
543 	/*
544 	 * Check if the start/stop logic was active when the unit was stopped.
545 	 * That way we can re-enable the start/stop logic when the process is
546 	 * scheduled again.  Configuration of the start/stop logic happens in
547 	 * function etm4_set_event_filters().
548 	 */
549 	control = readl_relaxed(drvdata->base + TRCVICTLR);
550 	/* TRCVICTLR::SSSTATUS, bit[9] */
551 	filters->ssstatus = (control & BIT(9));
552 
553 	return 0;
554 }
555 
etm4_disable_sysfs(struct coresight_device * csdev)556 static void etm4_disable_sysfs(struct coresight_device *csdev)
557 {
558 	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
559 
560 	/*
561 	 * Taking hotplug lock here protects from clocks getting disabled
562 	 * with tracing being left on (crash scenario) if user disable occurs
563 	 * after cpu online mask indicates the cpu is offline but before the
564 	 * DYING hotplug callback is serviced by the ETM driver.
565 	 */
566 	cpus_read_lock();
567 	spin_lock(&drvdata->spinlock);
568 
569 	/*
570 	 * Executing etm4_disable_hw on the cpu whose ETM is being disabled
571 	 * ensures that register writes occur when cpu is powered.
572 	 */
573 	smp_call_function_single(drvdata->cpu, etm4_disable_hw, drvdata, 1);
574 
575 	spin_unlock(&drvdata->spinlock);
576 	cpus_read_unlock();
577 
578 	dev_dbg(&csdev->dev, "ETM tracing disabled\n");
579 }
580 
etm4_disable(struct coresight_device * csdev,struct perf_event * event)581 static void etm4_disable(struct coresight_device *csdev,
582 			 struct perf_event *event)
583 {
584 	u32 mode;
585 	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
586 
587 	/*
588 	 * For as long as the tracer isn't disabled another entity can't
589 	 * change its status.  As such we can read the status here without
590 	 * fearing it will change under us.
591 	 */
592 	mode = local_read(&drvdata->mode);
593 
594 	switch (mode) {
595 	case CS_MODE_DISABLED:
596 		break;
597 	case CS_MODE_SYSFS:
598 		etm4_disable_sysfs(csdev);
599 		break;
600 	case CS_MODE_PERF:
601 		etm4_disable_perf(csdev, event);
602 		break;
603 	}
604 
605 	if (mode)
606 		local_set(&drvdata->mode, CS_MODE_DISABLED);
607 }
608 
609 static const struct coresight_ops_source etm4_source_ops = {
610 	.cpu_id		= etm4_cpu_id,
611 	.trace_id	= etm4_trace_id,
612 	.enable		= etm4_enable,
613 	.disable	= etm4_disable,
614 };
615 
616 static const struct coresight_ops etm4_cs_ops = {
617 	.source_ops	= &etm4_source_ops,
618 };
619 
etm4_init_arch_data(void * info)620 static void etm4_init_arch_data(void *info)
621 {
622 	u32 etmidr0;
623 	u32 etmidr1;
624 	u32 etmidr2;
625 	u32 etmidr3;
626 	u32 etmidr4;
627 	u32 etmidr5;
628 	struct etmv4_drvdata *drvdata = info;
629 	int i;
630 
631 	/* Make sure all registers are accessible */
632 	etm4_os_unlock(drvdata);
633 
634 	CS_UNLOCK(drvdata->base);
635 
636 	/* find all capabilities of the tracing unit */
637 	etmidr0 = readl_relaxed(drvdata->base + TRCIDR0);
638 
639 	/* INSTP0, bits[2:1] P0 tracing support field */
640 	if (BMVAL(etmidr0, 1, 1) && BMVAL(etmidr0, 2, 2))
641 		drvdata->instrp0 = true;
642 	else
643 		drvdata->instrp0 = false;
644 
645 	/* TRCBB, bit[5] Branch broadcast tracing support bit */
646 	if (BMVAL(etmidr0, 5, 5))
647 		drvdata->trcbb = true;
648 	else
649 		drvdata->trcbb = false;
650 
651 	/* TRCCOND, bit[6] Conditional instruction tracing support bit */
652 	if (BMVAL(etmidr0, 6, 6))
653 		drvdata->trccond = true;
654 	else
655 		drvdata->trccond = false;
656 
657 	/* TRCCCI, bit[7] Cycle counting instruction bit */
658 	if (BMVAL(etmidr0, 7, 7))
659 		drvdata->trccci = true;
660 	else
661 		drvdata->trccci = false;
662 
663 	/* RETSTACK, bit[9] Return stack bit */
664 	if (BMVAL(etmidr0, 9, 9))
665 		drvdata->retstack = true;
666 	else
667 		drvdata->retstack = false;
668 
669 	/* NUMEVENT, bits[11:10] Number of events field */
670 	drvdata->nr_event = BMVAL(etmidr0, 10, 11);
671 	/* QSUPP, bits[16:15] Q element support field */
672 	drvdata->q_support = BMVAL(etmidr0, 15, 16);
673 	/* TSSIZE, bits[28:24] Global timestamp size field */
674 	drvdata->ts_size = BMVAL(etmidr0, 24, 28);
675 
676 	/* base architecture of trace unit */
677 	etmidr1 = readl_relaxed(drvdata->base + TRCIDR1);
678 	/*
679 	 * TRCARCHMIN, bits[7:4] architecture the minor version number
680 	 * TRCARCHMAJ, bits[11:8] architecture major versin number
681 	 */
682 	drvdata->arch = BMVAL(etmidr1, 4, 11);
683 	drvdata->config.arch = drvdata->arch;
684 
685 	/* maximum size of resources */
686 	etmidr2 = readl_relaxed(drvdata->base + TRCIDR2);
687 	/* CIDSIZE, bits[9:5] Indicates the Context ID size */
688 	drvdata->ctxid_size = BMVAL(etmidr2, 5, 9);
689 	/* VMIDSIZE, bits[14:10] Indicates the VMID size */
690 	drvdata->vmid_size = BMVAL(etmidr2, 10, 14);
691 	/* CCSIZE, bits[28:25] size of the cycle counter in bits minus 12 */
692 	drvdata->ccsize = BMVAL(etmidr2, 25, 28);
693 
694 	etmidr3 = readl_relaxed(drvdata->base + TRCIDR3);
695 	/* CCITMIN, bits[11:0] minimum threshold value that can be programmed */
696 	drvdata->ccitmin = BMVAL(etmidr3, 0, 11);
697 	/* EXLEVEL_S, bits[19:16] Secure state instruction tracing */
698 	drvdata->s_ex_level = BMVAL(etmidr3, 16, 19);
699 	/* EXLEVEL_NS, bits[23:20] Non-secure state instruction tracing */
700 	drvdata->ns_ex_level = BMVAL(etmidr3, 20, 23);
701 
702 	/*
703 	 * TRCERR, bit[24] whether a trace unit can trace a
704 	 * system error exception.
705 	 */
706 	if (BMVAL(etmidr3, 24, 24))
707 		drvdata->trc_error = true;
708 	else
709 		drvdata->trc_error = false;
710 
711 	/* SYNCPR, bit[25] implementation has a fixed synchronization period? */
712 	if (BMVAL(etmidr3, 25, 25))
713 		drvdata->syncpr = true;
714 	else
715 		drvdata->syncpr = false;
716 
717 	/* STALLCTL, bit[26] is stall control implemented? */
718 	if (BMVAL(etmidr3, 26, 26))
719 		drvdata->stallctl = true;
720 	else
721 		drvdata->stallctl = false;
722 
723 	/* SYSSTALL, bit[27] implementation can support stall control? */
724 	if (BMVAL(etmidr3, 27, 27))
725 		drvdata->sysstall = true;
726 	else
727 		drvdata->sysstall = false;
728 
729 	/* NUMPROC, bits[30:28] the number of PEs available for tracing */
730 	drvdata->nr_pe = BMVAL(etmidr3, 28, 30);
731 
732 	/* NOOVERFLOW, bit[31] is trace overflow prevention supported */
733 	if (BMVAL(etmidr3, 31, 31))
734 		drvdata->nooverflow = true;
735 	else
736 		drvdata->nooverflow = false;
737 
738 	/* number of resources trace unit supports */
739 	etmidr4 = readl_relaxed(drvdata->base + TRCIDR4);
740 	/* NUMACPAIRS, bits[0:3] number of addr comparator pairs for tracing */
741 	drvdata->nr_addr_cmp = BMVAL(etmidr4, 0, 3);
742 	/* NUMPC, bits[15:12] number of PE comparator inputs for tracing */
743 	drvdata->nr_pe_cmp = BMVAL(etmidr4, 12, 15);
744 	/*
745 	 * NUMRSPAIR, bits[19:16]
746 	 * The number of resource pairs conveyed by the HW starts at 0, i.e a
747 	 * value of 0x0 indicate 1 resource pair, 0x1 indicate two and so on.
748 	 * As such add 1 to the value of NUMRSPAIR for a better representation.
749 	 *
750 	 * For ETM v4.3 and later, 0x0 means 0, and no pairs are available -
751 	 * the default TRUE and FALSE resource selectors are omitted.
752 	 * Otherwise for values 0x1 and above the number is N + 1 as per v4.2.
753 	 */
754 	drvdata->nr_resource = BMVAL(etmidr4, 16, 19);
755 	if ((drvdata->arch < ETM4X_ARCH_4V3) || (drvdata->nr_resource > 0))
756 		drvdata->nr_resource += 1;
757 	/*
758 	 * NUMSSCC, bits[23:20] the number of single-shot
759 	 * comparator control for tracing. Read any status regs as these
760 	 * also contain RO capability data.
761 	 */
762 	drvdata->nr_ss_cmp = BMVAL(etmidr4, 20, 23);
763 	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
764 		drvdata->config.ss_status[i] =
765 			readl_relaxed(drvdata->base + TRCSSCSRn(i));
766 	}
767 	/* NUMCIDC, bits[27:24] number of Context ID comparators for tracing */
768 	drvdata->numcidc = BMVAL(etmidr4, 24, 27);
769 	/* NUMVMIDC, bits[31:28] number of VMID comparators for tracing */
770 	drvdata->numvmidc = BMVAL(etmidr4, 28, 31);
771 
772 	etmidr5 = readl_relaxed(drvdata->base + TRCIDR5);
773 	/* NUMEXTIN, bits[8:0] number of external inputs implemented */
774 	drvdata->nr_ext_inp = BMVAL(etmidr5, 0, 8);
775 	/* TRACEIDSIZE, bits[21:16] indicates the trace ID width */
776 	drvdata->trcid_size = BMVAL(etmidr5, 16, 21);
777 	/* ATBTRIG, bit[22] implementation can support ATB triggers? */
778 	if (BMVAL(etmidr5, 22, 22))
779 		drvdata->atbtrig = true;
780 	else
781 		drvdata->atbtrig = false;
782 	/*
783 	 * LPOVERRIDE, bit[23] implementation supports
784 	 * low-power state override
785 	 */
786 	if (BMVAL(etmidr5, 23, 23) && (!drvdata->skip_power_up))
787 		drvdata->lpoverride = true;
788 	else
789 		drvdata->lpoverride = false;
790 	/* NUMSEQSTATE, bits[27:25] number of sequencer states implemented */
791 	drvdata->nrseqstate = BMVAL(etmidr5, 25, 27);
792 	/* NUMCNTR, bits[30:28] number of counters available for tracing */
793 	drvdata->nr_cntr = BMVAL(etmidr5, 28, 30);
794 	CS_LOCK(drvdata->base);
795 }
796 
797 /* Set ELx trace filter access in the TRCVICTLR register */
etm4_set_victlr_access(struct etmv4_config * config)798 static void etm4_set_victlr_access(struct etmv4_config *config)
799 {
800 	u64 access_type;
801 
802 	config->vinst_ctrl &= ~(ETM_EXLEVEL_S_VICTLR_MASK | ETM_EXLEVEL_NS_VICTLR_MASK);
803 
804 	/*
805 	 * TRCVICTLR::EXLEVEL_NS:EXLEVELS: Set kernel / user filtering
806 	 * bits in vinst_ctrl, same bit pattern as TRCACATRn values returned by
807 	 * etm4_get_access_type() but with a relative shift in this register.
808 	 */
809 	access_type = etm4_get_access_type(config) << ETM_EXLEVEL_LSHIFT_TRCVICTLR;
810 	config->vinst_ctrl |= (u32)access_type;
811 }
812 
etm4_set_default_config(struct etmv4_config * config)813 static void etm4_set_default_config(struct etmv4_config *config)
814 {
815 	/* disable all events tracing */
816 	config->eventctrl0 = 0x0;
817 	config->eventctrl1 = 0x0;
818 
819 	/* disable stalling */
820 	config->stall_ctrl = 0x0;
821 
822 	/* enable trace synchronization every 4096 bytes, if available */
823 	config->syncfreq = 0xC;
824 
825 	/* disable timestamp event */
826 	config->ts_ctrl = 0x0;
827 
828 	/* TRCVICTLR::EVENT = 0x01, select the always on logic */
829 	config->vinst_ctrl = BIT(0);
830 
831 	/* TRCVICTLR::EXLEVEL_NS:EXLEVELS: Set kernel / user filtering */
832 	etm4_set_victlr_access(config);
833 }
834 
etm4_get_ns_access_type(struct etmv4_config * config)835 static u64 etm4_get_ns_access_type(struct etmv4_config *config)
836 {
837 	u64 access_type = 0;
838 
839 	/*
840 	 * EXLEVEL_NS, bits[15:12]
841 	 * The Exception levels are:
842 	 *   Bit[12] Exception level 0 - Application
843 	 *   Bit[13] Exception level 1 - OS
844 	 *   Bit[14] Exception level 2 - Hypervisor
845 	 *   Bit[15] Never implemented
846 	 */
847 	if (!is_kernel_in_hyp_mode()) {
848 		/* Stay away from hypervisor mode for non-VHE */
849 		access_type =  ETM_EXLEVEL_NS_HYP;
850 		if (config->mode & ETM_MODE_EXCL_KERN)
851 			access_type |= ETM_EXLEVEL_NS_OS;
852 	} else if (config->mode & ETM_MODE_EXCL_KERN) {
853 		access_type = ETM_EXLEVEL_NS_HYP;
854 	}
855 
856 	if (config->mode & ETM_MODE_EXCL_USER)
857 		access_type |= ETM_EXLEVEL_NS_APP;
858 
859 	return access_type;
860 }
861 
etm4_get_access_type(struct etmv4_config * config)862 static u64 etm4_get_access_type(struct etmv4_config *config)
863 {
864 	u64 access_type = etm4_get_ns_access_type(config);
865 	u64 s_hyp = (config->arch & 0x0f) >= 0x4 ? ETM_EXLEVEL_S_HYP : 0;
866 
867 	/*
868 	 * EXLEVEL_S, bits[11:8], don't trace anything happening
869 	 * in secure state.
870 	 */
871 	access_type |= (ETM_EXLEVEL_S_APP	|
872 			ETM_EXLEVEL_S_OS	|
873 			s_hyp			|
874 			ETM_EXLEVEL_S_MON);
875 
876 	return access_type;
877 }
878 
etm4_set_comparator_filter(struct etmv4_config * config,u64 start,u64 stop,int comparator)879 static void etm4_set_comparator_filter(struct etmv4_config *config,
880 				       u64 start, u64 stop, int comparator)
881 {
882 	u64 access_type = etm4_get_access_type(config);
883 
884 	/* First half of default address comparator */
885 	config->addr_val[comparator] = start;
886 	config->addr_acc[comparator] = access_type;
887 	config->addr_type[comparator] = ETM_ADDR_TYPE_RANGE;
888 
889 	/* Second half of default address comparator */
890 	config->addr_val[comparator + 1] = stop;
891 	config->addr_acc[comparator + 1] = access_type;
892 	config->addr_type[comparator + 1] = ETM_ADDR_TYPE_RANGE;
893 
894 	/*
895 	 * Configure the ViewInst function to include this address range
896 	 * comparator.
897 	 *
898 	 * @comparator is divided by two since it is the index in the
899 	 * etmv4_config::addr_val array but register TRCVIIECTLR deals with
900 	 * address range comparator _pairs_.
901 	 *
902 	 * Therefore:
903 	 *	index 0 -> compatator pair 0
904 	 *	index 2 -> comparator pair 1
905 	 *	index 4 -> comparator pair 2
906 	 *	...
907 	 *	index 14 -> comparator pair 7
908 	 */
909 	config->viiectlr |= BIT(comparator / 2);
910 }
911 
etm4_set_start_stop_filter(struct etmv4_config * config,u64 address,int comparator,enum etm_addr_type type)912 static void etm4_set_start_stop_filter(struct etmv4_config *config,
913 				       u64 address, int comparator,
914 				       enum etm_addr_type type)
915 {
916 	int shift;
917 	u64 access_type = etm4_get_access_type(config);
918 
919 	/* Configure the comparator */
920 	config->addr_val[comparator] = address;
921 	config->addr_acc[comparator] = access_type;
922 	config->addr_type[comparator] = type;
923 
924 	/*
925 	 * Configure ViewInst Start-Stop control register.
926 	 * Addresses configured to start tracing go from bit 0 to n-1,
927 	 * while those configured to stop tracing from 16 to 16 + n-1.
928 	 */
929 	shift = (type == ETM_ADDR_TYPE_START ? 0 : 16);
930 	config->vissctlr |= BIT(shift + comparator);
931 }
932 
etm4_set_default_filter(struct etmv4_config * config)933 static void etm4_set_default_filter(struct etmv4_config *config)
934 {
935 	/* Trace everything 'default' filter achieved by no filtering */
936 	config->viiectlr = 0x0;
937 
938 	/*
939 	 * TRCVICTLR::SSSTATUS == 1, the start-stop logic is
940 	 * in the started state
941 	 */
942 	config->vinst_ctrl |= BIT(9);
943 	config->mode |= ETM_MODE_VIEWINST_STARTSTOP;
944 
945 	/* No start-stop filtering for ViewInst */
946 	config->vissctlr = 0x0;
947 }
948 
etm4_set_default(struct etmv4_config * config)949 static void etm4_set_default(struct etmv4_config *config)
950 {
951 	if (WARN_ON_ONCE(!config))
952 		return;
953 
954 	/*
955 	 * Make default initialisation trace everything
956 	 *
957 	 * This is done by a minimum default config sufficient to enable
958 	 * full instruction trace - with a default filter for trace all
959 	 * achieved by having no filtering.
960 	 */
961 	etm4_set_default_config(config);
962 	etm4_set_default_filter(config);
963 }
964 
etm4_get_next_comparator(struct etmv4_drvdata * drvdata,u32 type)965 static int etm4_get_next_comparator(struct etmv4_drvdata *drvdata, u32 type)
966 {
967 	int nr_comparator, index = 0;
968 	struct etmv4_config *config = &drvdata->config;
969 
970 	/*
971 	 * nr_addr_cmp holds the number of comparator _pair_, so time 2
972 	 * for the total number of comparators.
973 	 */
974 	nr_comparator = drvdata->nr_addr_cmp * 2;
975 
976 	/* Go through the tally of comparators looking for a free one. */
977 	while (index < nr_comparator) {
978 		switch (type) {
979 		case ETM_ADDR_TYPE_RANGE:
980 			if (config->addr_type[index] == ETM_ADDR_TYPE_NONE &&
981 			    config->addr_type[index + 1] == ETM_ADDR_TYPE_NONE)
982 				return index;
983 
984 			/* Address range comparators go in pairs */
985 			index += 2;
986 			break;
987 		case ETM_ADDR_TYPE_START:
988 		case ETM_ADDR_TYPE_STOP:
989 			if (config->addr_type[index] == ETM_ADDR_TYPE_NONE)
990 				return index;
991 
992 			/* Start/stop address can have odd indexes */
993 			index += 1;
994 			break;
995 		default:
996 			return -EINVAL;
997 		}
998 	}
999 
1000 	/* If we are here all the comparators have been used. */
1001 	return -ENOSPC;
1002 }
1003 
etm4_set_event_filters(struct etmv4_drvdata * drvdata,struct perf_event * event)1004 static int etm4_set_event_filters(struct etmv4_drvdata *drvdata,
1005 				  struct perf_event *event)
1006 {
1007 	int i, comparator, ret = 0;
1008 	u64 address;
1009 	struct etmv4_config *config = &drvdata->config;
1010 	struct etm_filters *filters = event->hw.addr_filters;
1011 
1012 	if (!filters)
1013 		goto default_filter;
1014 
1015 	/* Sync events with what Perf got */
1016 	perf_event_addr_filters_sync(event);
1017 
1018 	/*
1019 	 * If there are no filters to deal with simply go ahead with
1020 	 * the default filter, i.e the entire address range.
1021 	 */
1022 	if (!filters->nr_filters)
1023 		goto default_filter;
1024 
1025 	for (i = 0; i < filters->nr_filters; i++) {
1026 		struct etm_filter *filter = &filters->etm_filter[i];
1027 		enum etm_addr_type type = filter->type;
1028 
1029 		/* See if a comparator is free. */
1030 		comparator = etm4_get_next_comparator(drvdata, type);
1031 		if (comparator < 0) {
1032 			ret = comparator;
1033 			goto out;
1034 		}
1035 
1036 		switch (type) {
1037 		case ETM_ADDR_TYPE_RANGE:
1038 			etm4_set_comparator_filter(config,
1039 						   filter->start_addr,
1040 						   filter->stop_addr,
1041 						   comparator);
1042 			/*
1043 			 * TRCVICTLR::SSSTATUS == 1, the start-stop logic is
1044 			 * in the started state
1045 			 */
1046 			config->vinst_ctrl |= BIT(9);
1047 
1048 			/* No start-stop filtering for ViewInst */
1049 			config->vissctlr = 0x0;
1050 			break;
1051 		case ETM_ADDR_TYPE_START:
1052 		case ETM_ADDR_TYPE_STOP:
1053 			/* Get the right start or stop address */
1054 			address = (type == ETM_ADDR_TYPE_START ?
1055 				   filter->start_addr :
1056 				   filter->stop_addr);
1057 
1058 			/* Configure comparator */
1059 			etm4_set_start_stop_filter(config, address,
1060 						   comparator, type);
1061 
1062 			/*
1063 			 * If filters::ssstatus == 1, trace acquisition was
1064 			 * started but the process was yanked away before the
1065 			 * the stop address was hit.  As such the start/stop
1066 			 * logic needs to be re-started so that tracing can
1067 			 * resume where it left.
1068 			 *
1069 			 * The start/stop logic status when a process is
1070 			 * scheduled out is checked in function
1071 			 * etm4_disable_perf().
1072 			 */
1073 			if (filters->ssstatus)
1074 				config->vinst_ctrl |= BIT(9);
1075 
1076 			/* No include/exclude filtering for ViewInst */
1077 			config->viiectlr = 0x0;
1078 			break;
1079 		default:
1080 			ret = -EINVAL;
1081 			goto out;
1082 		}
1083 	}
1084 
1085 	goto out;
1086 
1087 
1088 default_filter:
1089 	etm4_set_default_filter(config);
1090 
1091 out:
1092 	return ret;
1093 }
1094 
etm4_config_trace_mode(struct etmv4_config * config)1095 void etm4_config_trace_mode(struct etmv4_config *config)
1096 {
1097 	u32 mode;
1098 
1099 	mode = config->mode;
1100 	mode &= (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER);
1101 
1102 	/* excluding kernel AND user space doesn't make sense */
1103 	WARN_ON_ONCE(mode == (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER));
1104 
1105 	/* nothing to do if neither flags are set */
1106 	if (!(mode & ETM_MODE_EXCL_KERN) && !(mode & ETM_MODE_EXCL_USER))
1107 		return;
1108 
1109 	etm4_set_victlr_access(config);
1110 }
1111 
etm4_online_cpu(unsigned int cpu)1112 static int etm4_online_cpu(unsigned int cpu)
1113 {
1114 	if (!etmdrvdata[cpu])
1115 		return 0;
1116 
1117 	if (etmdrvdata[cpu]->boot_enable && !etmdrvdata[cpu]->sticky_enable)
1118 		coresight_enable(etmdrvdata[cpu]->csdev);
1119 	return 0;
1120 }
1121 
etm4_starting_cpu(unsigned int cpu)1122 static int etm4_starting_cpu(unsigned int cpu)
1123 {
1124 	if (!etmdrvdata[cpu])
1125 		return 0;
1126 
1127 	spin_lock(&etmdrvdata[cpu]->spinlock);
1128 	if (!etmdrvdata[cpu]->os_unlock)
1129 		etm4_os_unlock(etmdrvdata[cpu]);
1130 
1131 	if (local_read(&etmdrvdata[cpu]->mode))
1132 		etm4_enable_hw(etmdrvdata[cpu]);
1133 	spin_unlock(&etmdrvdata[cpu]->spinlock);
1134 	return 0;
1135 }
1136 
etm4_dying_cpu(unsigned int cpu)1137 static int etm4_dying_cpu(unsigned int cpu)
1138 {
1139 	if (!etmdrvdata[cpu])
1140 		return 0;
1141 
1142 	spin_lock(&etmdrvdata[cpu]->spinlock);
1143 	if (local_read(&etmdrvdata[cpu]->mode))
1144 		etm4_disable_hw(etmdrvdata[cpu]);
1145 	spin_unlock(&etmdrvdata[cpu]->spinlock);
1146 	return 0;
1147 }
1148 
etm4_init_trace_id(struct etmv4_drvdata * drvdata)1149 static void etm4_init_trace_id(struct etmv4_drvdata *drvdata)
1150 {
1151 	drvdata->trcid = coresight_get_trace_id(drvdata->cpu);
1152 }
1153 
etm4_cpu_save(struct etmv4_drvdata * drvdata)1154 static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
1155 {
1156 	int i, ret = 0;
1157 	struct etmv4_save_state *state;
1158 	struct device *etm_dev = &drvdata->csdev->dev;
1159 
1160 	/*
1161 	 * As recommended by 3.4.1 ("The procedure when powering down the PE")
1162 	 * of ARM IHI 0064D
1163 	 */
1164 	dsb(sy);
1165 	isb();
1166 
1167 	CS_UNLOCK(drvdata->base);
1168 
1169 	/* Lock the OS lock to disable trace and external debugger access */
1170 	etm4_os_lock(drvdata);
1171 
1172 	/* wait for TRCSTATR.PMSTABLE to go up */
1173 	if (coresight_timeout(drvdata->base, TRCSTATR,
1174 			      TRCSTATR_PMSTABLE_BIT, 1)) {
1175 		dev_err(etm_dev,
1176 			"timeout while waiting for PM Stable Status\n");
1177 		etm4_os_unlock(drvdata);
1178 		ret = -EBUSY;
1179 		goto out;
1180 	}
1181 
1182 	state = drvdata->save_state;
1183 
1184 	state->trcprgctlr = readl(drvdata->base + TRCPRGCTLR);
1185 	if (drvdata->nr_pe)
1186 		state->trcprocselr = readl(drvdata->base + TRCPROCSELR);
1187 	state->trcconfigr = readl(drvdata->base + TRCCONFIGR);
1188 	state->trcauxctlr = readl(drvdata->base + TRCAUXCTLR);
1189 	state->trceventctl0r = readl(drvdata->base + TRCEVENTCTL0R);
1190 	state->trceventctl1r = readl(drvdata->base + TRCEVENTCTL1R);
1191 	if (drvdata->stallctl)
1192 		state->trcstallctlr = readl(drvdata->base + TRCSTALLCTLR);
1193 	state->trctsctlr = readl(drvdata->base + TRCTSCTLR);
1194 	state->trcsyncpr = readl(drvdata->base + TRCSYNCPR);
1195 	state->trcccctlr = readl(drvdata->base + TRCCCCTLR);
1196 	state->trcbbctlr = readl(drvdata->base + TRCBBCTLR);
1197 	state->trctraceidr = readl(drvdata->base + TRCTRACEIDR);
1198 	state->trcqctlr = readl(drvdata->base + TRCQCTLR);
1199 
1200 	state->trcvictlr = readl(drvdata->base + TRCVICTLR);
1201 	state->trcviiectlr = readl(drvdata->base + TRCVIIECTLR);
1202 	state->trcvissctlr = readl(drvdata->base + TRCVISSCTLR);
1203 	if (drvdata->nr_pe_cmp)
1204 		state->trcvipcssctlr = readl(drvdata->base + TRCVIPCSSCTLR);
1205 	state->trcvdctlr = readl(drvdata->base + TRCVDCTLR);
1206 	state->trcvdsacctlr = readl(drvdata->base + TRCVDSACCTLR);
1207 	state->trcvdarcctlr = readl(drvdata->base + TRCVDARCCTLR);
1208 
1209 	for (i = 0; i < drvdata->nrseqstate - 1; i++)
1210 		state->trcseqevr[i] = readl(drvdata->base + TRCSEQEVRn(i));
1211 
1212 	state->trcseqrstevr = readl(drvdata->base + TRCSEQRSTEVR);
1213 	state->trcseqstr = readl(drvdata->base + TRCSEQSTR);
1214 	state->trcextinselr = readl(drvdata->base + TRCEXTINSELR);
1215 
1216 	for (i = 0; i < drvdata->nr_cntr; i++) {
1217 		state->trccntrldvr[i] = readl(drvdata->base + TRCCNTRLDVRn(i));
1218 		state->trccntctlr[i] = readl(drvdata->base + TRCCNTCTLRn(i));
1219 		state->trccntvr[i] = readl(drvdata->base + TRCCNTVRn(i));
1220 	}
1221 
1222 	for (i = 0; i < drvdata->nr_resource * 2; i++)
1223 		state->trcrsctlr[i] = readl(drvdata->base + TRCRSCTLRn(i));
1224 
1225 	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
1226 		state->trcssccr[i] = readl(drvdata->base + TRCSSCCRn(i));
1227 		state->trcsscsr[i] = readl(drvdata->base + TRCSSCSRn(i));
1228 		state->trcsspcicr[i] = readl(drvdata->base + TRCSSPCICRn(i));
1229 	}
1230 
1231 	for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) {
1232 		state->trcacvr[i] = readq(drvdata->base + TRCACVRn(i));
1233 		state->trcacatr[i] = readq(drvdata->base + TRCACATRn(i));
1234 	}
1235 
1236 	/*
1237 	 * Data trace stream is architecturally prohibited for A profile cores
1238 	 * so we don't save (or later restore) trcdvcvr and trcdvcmr - As per
1239 	 * section 1.3.4 ("Possible functional configurations of an ETMv4 trace
1240 	 * unit") of ARM IHI 0064D.
1241 	 */
1242 
1243 	for (i = 0; i < drvdata->numcidc; i++)
1244 		state->trccidcvr[i] = readq(drvdata->base + TRCCIDCVRn(i));
1245 
1246 	for (i = 0; i < drvdata->numvmidc; i++)
1247 		state->trcvmidcvr[i] = readq(drvdata->base + TRCVMIDCVRn(i));
1248 
1249 	state->trccidcctlr0 = readl(drvdata->base + TRCCIDCCTLR0);
1250 	if (drvdata->numcidc > 4)
1251 		state->trccidcctlr1 = readl(drvdata->base + TRCCIDCCTLR1);
1252 
1253 	state->trcvmidcctlr0 = readl(drvdata->base + TRCVMIDCCTLR0);
1254 	if (drvdata->numvmidc > 4)
1255 		state->trcvmidcctlr1 = readl(drvdata->base + TRCVMIDCCTLR1);
1256 
1257 	state->trcclaimset = readl(drvdata->base + TRCCLAIMCLR);
1258 
1259 	if (!drvdata->skip_power_up)
1260 		state->trcpdcr = readl(drvdata->base + TRCPDCR);
1261 
1262 	/* wait for TRCSTATR.IDLE to go up */
1263 	if (coresight_timeout(drvdata->base, TRCSTATR, TRCSTATR_IDLE_BIT, 1)) {
1264 		dev_err(etm_dev,
1265 			"timeout while waiting for Idle Trace Status\n");
1266 		etm4_os_unlock(drvdata);
1267 		ret = -EBUSY;
1268 		goto out;
1269 	}
1270 
1271 	drvdata->state_needs_restore = true;
1272 
1273 	/*
1274 	 * Power can be removed from the trace unit now. We do this to
1275 	 * potentially save power on systems that respect the TRCPDCR_PU
1276 	 * despite requesting software to save/restore state.
1277 	 */
1278 	if (!drvdata->skip_power_up)
1279 		writel_relaxed((state->trcpdcr & ~TRCPDCR_PU),
1280 				drvdata->base + TRCPDCR);
1281 out:
1282 	CS_LOCK(drvdata->base);
1283 	return ret;
1284 }
1285 
etm4_cpu_restore(struct etmv4_drvdata * drvdata)1286 static void etm4_cpu_restore(struct etmv4_drvdata *drvdata)
1287 {
1288 	int i;
1289 	struct etmv4_save_state *state = drvdata->save_state;
1290 
1291 	CS_UNLOCK(drvdata->base);
1292 
1293 	writel_relaxed(state->trcclaimset, drvdata->base + TRCCLAIMSET);
1294 
1295 	writel_relaxed(state->trcprgctlr, drvdata->base + TRCPRGCTLR);
1296 	if (drvdata->nr_pe)
1297 		writel_relaxed(state->trcprocselr, drvdata->base + TRCPROCSELR);
1298 	writel_relaxed(state->trcconfigr, drvdata->base + TRCCONFIGR);
1299 	writel_relaxed(state->trcauxctlr, drvdata->base + TRCAUXCTLR);
1300 	writel_relaxed(state->trceventctl0r, drvdata->base + TRCEVENTCTL0R);
1301 	writel_relaxed(state->trceventctl1r, drvdata->base + TRCEVENTCTL1R);
1302 	if (drvdata->stallctl)
1303 		writel_relaxed(state->trcstallctlr, drvdata->base + TRCSTALLCTLR);
1304 	writel_relaxed(state->trctsctlr, drvdata->base + TRCTSCTLR);
1305 	writel_relaxed(state->trcsyncpr, drvdata->base + TRCSYNCPR);
1306 	writel_relaxed(state->trcccctlr, drvdata->base + TRCCCCTLR);
1307 	writel_relaxed(state->trcbbctlr, drvdata->base + TRCBBCTLR);
1308 	writel_relaxed(state->trctraceidr, drvdata->base + TRCTRACEIDR);
1309 	writel_relaxed(state->trcqctlr, drvdata->base + TRCQCTLR);
1310 
1311 	writel_relaxed(state->trcvictlr, drvdata->base + TRCVICTLR);
1312 	writel_relaxed(state->trcviiectlr, drvdata->base + TRCVIIECTLR);
1313 	writel_relaxed(state->trcvissctlr, drvdata->base + TRCVISSCTLR);
1314 	if (drvdata->nr_pe_cmp)
1315 		writel_relaxed(state->trcvipcssctlr, drvdata->base + TRCVIPCSSCTLR);
1316 	writel_relaxed(state->trcvdctlr, drvdata->base + TRCVDCTLR);
1317 	writel_relaxed(state->trcvdsacctlr, drvdata->base + TRCVDSACCTLR);
1318 	writel_relaxed(state->trcvdarcctlr, drvdata->base + TRCVDARCCTLR);
1319 
1320 	for (i = 0; i < drvdata->nrseqstate - 1; i++)
1321 		writel_relaxed(state->trcseqevr[i],
1322 			       drvdata->base + TRCSEQEVRn(i));
1323 
1324 	writel_relaxed(state->trcseqrstevr, drvdata->base + TRCSEQRSTEVR);
1325 	writel_relaxed(state->trcseqstr, drvdata->base + TRCSEQSTR);
1326 	writel_relaxed(state->trcextinselr, drvdata->base + TRCEXTINSELR);
1327 
1328 	for (i = 0; i < drvdata->nr_cntr; i++) {
1329 		writel_relaxed(state->trccntrldvr[i],
1330 			       drvdata->base + TRCCNTRLDVRn(i));
1331 		writel_relaxed(state->trccntctlr[i],
1332 			       drvdata->base + TRCCNTCTLRn(i));
1333 		writel_relaxed(state->trccntvr[i],
1334 			       drvdata->base + TRCCNTVRn(i));
1335 	}
1336 
1337 	for (i = 0; i < drvdata->nr_resource * 2; i++)
1338 		writel_relaxed(state->trcrsctlr[i],
1339 			       drvdata->base + TRCRSCTLRn(i));
1340 
1341 	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
1342 		writel_relaxed(state->trcssccr[i],
1343 			       drvdata->base + TRCSSCCRn(i));
1344 		writel_relaxed(state->trcsscsr[i],
1345 			       drvdata->base + TRCSSCSRn(i));
1346 		writel_relaxed(state->trcsspcicr[i],
1347 			       drvdata->base + TRCSSPCICRn(i));
1348 	}
1349 
1350 	for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) {
1351 		writeq_relaxed(state->trcacvr[i],
1352 			       drvdata->base + TRCACVRn(i));
1353 		writeq_relaxed(state->trcacatr[i],
1354 			       drvdata->base + TRCACATRn(i));
1355 	}
1356 
1357 	for (i = 0; i < drvdata->numcidc; i++)
1358 		writeq_relaxed(state->trccidcvr[i],
1359 			       drvdata->base + TRCCIDCVRn(i));
1360 
1361 	for (i = 0; i < drvdata->numvmidc; i++)
1362 		writeq_relaxed(state->trcvmidcvr[i],
1363 			       drvdata->base + TRCVMIDCVRn(i));
1364 
1365 	writel_relaxed(state->trccidcctlr0, drvdata->base + TRCCIDCCTLR0);
1366 	if (drvdata->numcidc > 4)
1367 		writel_relaxed(state->trccidcctlr1, drvdata->base + TRCCIDCCTLR1);
1368 
1369 	writel_relaxed(state->trcvmidcctlr0, drvdata->base + TRCVMIDCCTLR0);
1370 	if (drvdata->numvmidc > 4)
1371 		writel_relaxed(state->trcvmidcctlr1, drvdata->base + TRCVMIDCCTLR1);
1372 
1373 	writel_relaxed(state->trcclaimset, drvdata->base + TRCCLAIMSET);
1374 
1375 	if (!drvdata->skip_power_up)
1376 		writel_relaxed(state->trcpdcr, drvdata->base + TRCPDCR);
1377 
1378 	drvdata->state_needs_restore = false;
1379 
1380 	/*
1381 	 * As recommended by section 4.3.7 ("Synchronization when using the
1382 	 * memory-mapped interface") of ARM IHI 0064D
1383 	 */
1384 	dsb(sy);
1385 	isb();
1386 
1387 	/* Unlock the OS lock to re-enable trace and external debug access */
1388 	etm4_os_unlock(drvdata);
1389 	CS_LOCK(drvdata->base);
1390 }
1391 
etm4_cpu_pm_notify(struct notifier_block * nb,unsigned long cmd,void * v)1392 static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd,
1393 			      void *v)
1394 {
1395 	struct etmv4_drvdata *drvdata;
1396 	unsigned int cpu = smp_processor_id();
1397 
1398 	if (!etmdrvdata[cpu])
1399 		return NOTIFY_OK;
1400 
1401 	drvdata = etmdrvdata[cpu];
1402 
1403 	if (!drvdata->save_state)
1404 		return NOTIFY_OK;
1405 
1406 	if (WARN_ON_ONCE(drvdata->cpu != cpu))
1407 		return NOTIFY_BAD;
1408 
1409 	switch (cmd) {
1410 	case CPU_PM_ENTER:
1411 		/* save the state if self-hosted coresight is in use */
1412 		if (local_read(&drvdata->mode))
1413 			if (etm4_cpu_save(drvdata))
1414 				return NOTIFY_BAD;
1415 		break;
1416 	case CPU_PM_EXIT:
1417 	case CPU_PM_ENTER_FAILED:
1418 		if (drvdata->state_needs_restore)
1419 			etm4_cpu_restore(drvdata);
1420 		break;
1421 	default:
1422 		return NOTIFY_DONE;
1423 	}
1424 
1425 	return NOTIFY_OK;
1426 }
1427 
1428 static struct notifier_block etm4_cpu_pm_nb = {
1429 	.notifier_call = etm4_cpu_pm_notify,
1430 };
1431 
1432 /* Setup PM. Deals with error conditions and counts */
etm4_pm_setup(void)1433 static int __init etm4_pm_setup(void)
1434 {
1435 	int ret;
1436 
1437 	ret = cpu_pm_register_notifier(&etm4_cpu_pm_nb);
1438 	if (ret)
1439 		return ret;
1440 
1441 	ret = cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING,
1442 					"arm/coresight4:starting",
1443 					etm4_starting_cpu, etm4_dying_cpu);
1444 
1445 	if (ret)
1446 		goto unregister_notifier;
1447 
1448 	ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
1449 					"arm/coresight4:online",
1450 					etm4_online_cpu, NULL);
1451 
1452 	/* HP dyn state ID returned in ret on success */
1453 	if (ret > 0) {
1454 		hp_online = ret;
1455 		return 0;
1456 	}
1457 
1458 	/* failed dyn state - remove others */
1459 	cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
1460 
1461 unregister_notifier:
1462 	cpu_pm_unregister_notifier(&etm4_cpu_pm_nb);
1463 	return ret;
1464 }
1465 
etm4_pm_clear(void)1466 static void etm4_pm_clear(void)
1467 {
1468 	cpu_pm_unregister_notifier(&etm4_cpu_pm_nb);
1469 	cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
1470 	if (hp_online) {
1471 		cpuhp_remove_state_nocalls(hp_online);
1472 		hp_online = 0;
1473 	}
1474 }
1475 
etm4_probe(struct amba_device * adev,const struct amba_id * id)1476 static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
1477 {
1478 	int ret;
1479 	void __iomem *base;
1480 	struct device *dev = &adev->dev;
1481 	struct coresight_platform_data *pdata = NULL;
1482 	struct etmv4_drvdata *drvdata;
1483 	struct resource *res = &adev->res;
1484 	struct coresight_desc desc = { 0 };
1485 
1486 	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
1487 	if (!drvdata)
1488 		return -ENOMEM;
1489 
1490 	dev_set_drvdata(dev, drvdata);
1491 
1492 	if (pm_save_enable == PARAM_PM_SAVE_FIRMWARE)
1493 		pm_save_enable = coresight_loses_context_with_cpu(dev) ?
1494 			       PARAM_PM_SAVE_SELF_HOSTED : PARAM_PM_SAVE_NEVER;
1495 
1496 	if (pm_save_enable != PARAM_PM_SAVE_NEVER) {
1497 		drvdata->save_state = devm_kmalloc(dev,
1498 				sizeof(struct etmv4_save_state), GFP_KERNEL);
1499 		if (!drvdata->save_state)
1500 			return -ENOMEM;
1501 	}
1502 
1503 	if (fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up"))
1504 		drvdata->skip_power_up = true;
1505 
1506 	/* Validity for the resource is already checked by the AMBA core */
1507 	base = devm_ioremap_resource(dev, res);
1508 	if (IS_ERR(base))
1509 		return PTR_ERR(base);
1510 
1511 	drvdata->base = base;
1512 
1513 	spin_lock_init(&drvdata->spinlock);
1514 
1515 	drvdata->cpu = coresight_get_cpu(dev);
1516 	if (drvdata->cpu < 0)
1517 		return drvdata->cpu;
1518 
1519 	desc.name = devm_kasprintf(dev, GFP_KERNEL, "etm%d", drvdata->cpu);
1520 	if (!desc.name)
1521 		return -ENOMEM;
1522 
1523 	if (smp_call_function_single(drvdata->cpu,
1524 				etm4_init_arch_data,  drvdata, 1))
1525 		dev_err(dev, "ETM arch init failed\n");
1526 
1527 	if (etm4_arch_supported(drvdata->arch) == false)
1528 		return -EINVAL;
1529 
1530 	etm4_init_trace_id(drvdata);
1531 	etm4_set_default(&drvdata->config);
1532 
1533 	pdata = coresight_get_platform_data(dev);
1534 	if (IS_ERR(pdata))
1535 		return PTR_ERR(pdata);
1536 
1537 	adev->dev.platform_data = pdata;
1538 
1539 	desc.type = CORESIGHT_DEV_TYPE_SOURCE;
1540 	desc.subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_PROC;
1541 	desc.ops = &etm4_cs_ops;
1542 	desc.pdata = pdata;
1543 	desc.dev = dev;
1544 	desc.groups = coresight_etmv4_groups;
1545 	drvdata->csdev = coresight_register(&desc);
1546 	if (IS_ERR(drvdata->csdev))
1547 		return PTR_ERR(drvdata->csdev);
1548 
1549 	ret = etm_perf_symlink(drvdata->csdev, true);
1550 	if (ret) {
1551 		coresight_unregister(drvdata->csdev);
1552 		return ret;
1553 	}
1554 
1555 	etmdrvdata[drvdata->cpu] = drvdata;
1556 
1557 	pm_runtime_put(&adev->dev);
1558 	dev_info(&drvdata->csdev->dev, "CPU%d: ETM v%d.%d initialized\n",
1559 		 drvdata->cpu, drvdata->arch >> 4, drvdata->arch & 0xf);
1560 
1561 	if (boot_enable) {
1562 		coresight_enable(drvdata->csdev);
1563 		drvdata->boot_enable = true;
1564 	}
1565 
1566 	return 0;
1567 }
1568 
1569 static struct amba_cs_uci_id uci_id_etm4[] = {
1570 	{
1571 		/*  ETMv4 UCI data */
1572 		.devarch	= 0x47704a13,
1573 		.devarch_mask	= 0xfff0ffff,
1574 		.devtype	= 0x00000013,
1575 	}
1576 };
1577 
clear_etmdrvdata(void * info)1578 static void clear_etmdrvdata(void *info)
1579 {
1580 	int cpu = *(int *)info;
1581 
1582 	etmdrvdata[cpu] = NULL;
1583 }
1584 
etm4_remove(struct amba_device * adev)1585 static int etm4_remove(struct amba_device *adev)
1586 {
1587 	struct etmv4_drvdata *drvdata = dev_get_drvdata(&adev->dev);
1588 
1589 	etm_perf_symlink(drvdata->csdev, false);
1590 
1591 	/*
1592 	 * Taking hotplug lock here to avoid racing between etm4_remove and
1593 	 * CPU hotplug call backs.
1594 	 */
1595 	cpus_read_lock();
1596 	/*
1597 	 * The readers for etmdrvdata[] are CPU hotplug call backs
1598 	 * and PM notification call backs. Change etmdrvdata[i] on
1599 	 * CPU i ensures these call backs has consistent view
1600 	 * inside one call back function.
1601 	 */
1602 	if (smp_call_function_single(drvdata->cpu, clear_etmdrvdata, &drvdata->cpu, 1))
1603 		etmdrvdata[drvdata->cpu] = NULL;
1604 
1605 	cpus_read_unlock();
1606 
1607 	coresight_unregister(drvdata->csdev);
1608 
1609 	return 0;
1610 }
1611 
1612 static const struct amba_id etm4_ids[] = {
1613 	CS_AMBA_ID(0x000bb95d),			/* Cortex-A53 */
1614 	CS_AMBA_ID(0x000bb95e),			/* Cortex-A57 */
1615 	CS_AMBA_ID(0x000bb95a),			/* Cortex-A72 */
1616 	CS_AMBA_ID(0x000bb959),			/* Cortex-A73 */
1617 	CS_AMBA_UCI_ID(0x000bb9da, uci_id_etm4),/* Cortex-A35 */
1618 	CS_AMBA_UCI_ID(0x000bbd0c, uci_id_etm4),/* Neoverse N1 */
1619 	CS_AMBA_UCI_ID(0x000f0205, uci_id_etm4),/* Qualcomm Kryo */
1620 	CS_AMBA_UCI_ID(0x000f0211, uci_id_etm4),/* Qualcomm Kryo */
1621 	CS_AMBA_UCI_ID(0x000bb802, uci_id_etm4),/* Qualcomm Kryo 385 Cortex-A55 */
1622 	CS_AMBA_UCI_ID(0x000bb803, uci_id_etm4),/* Qualcomm Kryo 385 Cortex-A75 */
1623 	CS_AMBA_UCI_ID(0x000bb805, uci_id_etm4),/* Qualcomm Kryo 4XX Cortex-A55 */
1624 	CS_AMBA_UCI_ID(0x000bb804, uci_id_etm4),/* Qualcomm Kryo 4XX Cortex-A76 */
1625 	CS_AMBA_UCI_ID(0x000cc0af, uci_id_etm4),/* Marvell ThunderX2 */
1626 	CS_AMBA_UCI_ID(0x000b6d01, uci_id_etm4),/* HiSilicon-Hip08 */
1627 	CS_AMBA_UCI_ID(0x000b6d02, uci_id_etm4),/* HiSilicon-Hip09 */
1628 	{},
1629 };
1630 
1631 MODULE_DEVICE_TABLE(amba, etm4_ids);
1632 
1633 static struct amba_driver etm4x_driver = {
1634 	.drv = {
1635 		.name   = "coresight-etm4x",
1636 		.owner  = THIS_MODULE,
1637 		.suppress_bind_attrs = true,
1638 	},
1639 	.probe		= etm4_probe,
1640 	.remove         = etm4_remove,
1641 	.id_table	= etm4_ids,
1642 };
1643 
etm4x_init(void)1644 static int __init etm4x_init(void)
1645 {
1646 	int ret;
1647 
1648 	ret = etm4_pm_setup();
1649 
1650 	/* etm4_pm_setup() does its own cleanup - exit on error */
1651 	if (ret)
1652 		return ret;
1653 
1654 	ret = amba_driver_register(&etm4x_driver);
1655 	if (ret) {
1656 		pr_err("Error registering etm4x driver\n");
1657 		etm4_pm_clear();
1658 	}
1659 
1660 	return ret;
1661 }
1662 
etm4x_exit(void)1663 static void __exit etm4x_exit(void)
1664 {
1665 	amba_driver_unregister(&etm4x_driver);
1666 	etm4_pm_clear();
1667 }
1668 
1669 module_init(etm4x_init);
1670 module_exit(etm4x_exit);
1671 
1672 MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
1673 MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
1674 MODULE_DESCRIPTION("Arm CoreSight Program Flow Trace v4.x driver");
1675 MODULE_LICENSE("GPL v2");
1676