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