drivers/perf/fsl_imx8_ddr_perf.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright 2017 NXP
   4  * Copyright 2016 Freescale Semiconductor, Inc.
   5  */
   6
   7 #include <linux/bitfield.h>
   8 #include <linux/init.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/io.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <linux/of_address.h>
  14 #include <linux/of_device.h>
  15 #include <linux/of_irq.h>
  16 #include <linux/perf_event.h>
  17 #include <linux/slab.h>
  18
  19 #define COUNTER_CNTL            0x0
  20 #define COUNTER_READ            0x20
  21
  22 #define COUNTER_DPCR1           0x30
  23
  24 #define CNTL_OVER               0x1
  25 #define CNTL_CLEAR              0x2
  26 #define CNTL_EN                 0x4
  27 #define CNTL_EN_MASK            0xFFFFFFFB
  28 #define CNTL_CLEAR_MASK         0xFFFFFFFD
  29 #define CNTL_OVER_MASK          0xFFFFFFFE
  30
  31 #define CNTL_CSV_SHIFT          24
  32 #define CNTL_CSV_MASK           (0xFF << CNTL_CSV_SHIFT)
  33
  34 #define EVENT_CYCLES_ID         0
  35 #define EVENT_CYCLES_COUNTER    0
  36 #define NUM_COUNTERS            4
  37
  38 #define AXI_MASKING_REVERT      0xffff0000      /* AXI_MASKING(MSB 16bits) + AXI_ID(LSB 16bits) */
  39
  40 #define to_ddr_pmu(p)           container_of(p, struct ddr_pmu, pmu)
  41
  42 #define DDR_PERF_DEV_NAME       "imx8_ddr"
  43 #define DDR_CPUHP_CB_NAME       DDR_PERF_DEV_NAME "_perf_pmu"
  44
  45 static DEFINE_IDA(ddr_ida);
  46
  47 /* DDR Perf hardware feature */
  48 #define DDR_CAP_AXI_ID_FILTER                   0x1     /* support AXI ID filter */
  49 #define DDR_CAP_AXI_ID_FILTER_ENHANCED          0x3     /* support enhanced AXI ID filter */
  50
  51 struct fsl_ddr_devtype_data {
  52         unsigned int quirks;    /* quirks needed for different DDR Perf core */
  53 };
  54
  55 static const struct fsl_ddr_devtype_data imx8_devtype_data;
  56
  57 static const struct fsl_ddr_devtype_data imx8m_devtype_data = {
  58         .quirks = DDR_CAP_AXI_ID_FILTER,
  59 };
  60
  61 static const struct fsl_ddr_devtype_data imx8mp_devtype_data = {
  62         .quirks = DDR_CAP_AXI_ID_FILTER_ENHANCED,
  63 };
  64
  65 static const struct of_device_id imx_ddr_pmu_dt_ids[] = {
  66         { .compatible = "fsl,imx8-ddr-pmu", .data = &imx8_devtype_data},
  67         { .compatible = "fsl,imx8m-ddr-pmu", .data = &imx8m_devtype_data},
  68         { .compatible = "fsl,imx8mp-ddr-pmu", .data = &imx8mp_devtype_data},
  69         { /* sentinel */ }
  70 };
  71 MODULE_DEVICE_TABLE(of, imx_ddr_pmu_dt_ids);
  72
  73 struct ddr_pmu {
  74         struct pmu pmu;
  75         void __iomem *base;
  76         unsigned int cpu;
  77         struct  hlist_node node;
  78         struct  device *dev;
  79         struct perf_event *events[NUM_COUNTERS];
  80         int active_events;
  81         enum cpuhp_state cpuhp_state;
  82         const struct fsl_ddr_devtype_data *devtype_data;
  83         int irq;
  84         int id;
  85 };
  86
  87 enum ddr_perf_filter_capabilities {
  88         PERF_CAP_AXI_ID_FILTER = 0,
  89         PERF_CAP_AXI_ID_FILTER_ENHANCED,
  90         PERF_CAP_AXI_ID_FEAT_MAX,
  91 };
  92
  93 static u32 ddr_perf_filter_cap_get(struct ddr_pmu *pmu, int cap)
  94 {
  95         u32 quirks = pmu->devtype_data->quirks;
  96
  97         switch (cap) {
  98         case PERF_CAP_AXI_ID_FILTER:
  99                 return !!(quirks & DDR_CAP_AXI_ID_FILTER);
 100         case PERF_CAP_AXI_ID_FILTER_ENHANCED:
 101                 quirks &= DDR_CAP_AXI_ID_FILTER_ENHANCED;
 102                 return quirks == DDR_CAP_AXI_ID_FILTER_ENHANCED;
 103         default:
 104                 WARN(1, "unknown filter cap %d\n", cap);
 105         }
 106
 107         return 0;
 108 }
 109
 110 static ssize_t ddr_perf_filter_cap_show(struct device *dev,
 111                                         struct device_attribute *attr,
 112                                         char *buf)
 113 {
 114         struct ddr_pmu *pmu = dev_get_drvdata(dev);
 115         struct dev_ext_attribute *ea =
 116                 container_of(attr, struct dev_ext_attribute, attr);
 117         int cap = (long)ea->var;
 118
 119         return snprintf(buf, PAGE_SIZE, "%u\n",
 120                         ddr_perf_filter_cap_get(pmu, cap));
 121 }
 122
 123 #define PERF_EXT_ATTR_ENTRY(_name, _func, _var)                         \
 124         (&((struct dev_ext_attribute) {                                 \
 125                 __ATTR(_name, 0444, _func, NULL), (void *)_var          \
 126         }).attr.attr)
 127
 128 #define PERF_FILTER_EXT_ATTR_ENTRY(_name, _var)                         \
 129         PERF_EXT_ATTR_ENTRY(_name, ddr_perf_filter_cap_show, _var)
 130
 131 static struct attribute *ddr_perf_filter_cap_attr[] = {
 132         PERF_FILTER_EXT_ATTR_ENTRY(filter, PERF_CAP_AXI_ID_FILTER),
 133         PERF_FILTER_EXT_ATTR_ENTRY(enhanced_filter, PERF_CAP_AXI_ID_FILTER_ENHANCED),
 134         NULL,
 135 };
 136
 137 static struct attribute_group ddr_perf_filter_cap_attr_group = {
 138         .name = "caps",
 139         .attrs = ddr_perf_filter_cap_attr,
 140 };
 141
 142 static ssize_t ddr_perf_cpumask_show(struct device *dev,
 143                                 struct device_attribute *attr, char *buf)
 144 {
 145         struct ddr_pmu *pmu = dev_get_drvdata(dev);
 146
 147         return cpumap_print_to_pagebuf(true, buf, cpumask_of(pmu->cpu));
 148 }
 149
 150 static struct device_attribute ddr_perf_cpumask_attr =
 151         __ATTR(cpumask, 0444, ddr_perf_cpumask_show, NULL);
 152
 153 static struct attribute *ddr_perf_cpumask_attrs[] = {
 154         &ddr_perf_cpumask_attr.attr,
 155         NULL,
 156 };
 157
 158 static struct attribute_group ddr_perf_cpumask_attr_group = {
 159         .attrs = ddr_perf_cpumask_attrs,
 160 };
 161
 162 static ssize_t
 163 ddr_pmu_event_show(struct device *dev, struct device_attribute *attr,
 164                    char *page)
 165 {
 166         struct perf_pmu_events_attr *pmu_attr;
 167
 168         pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
 169         return sprintf(page, "event=0x%02llx\n", pmu_attr->id);
 170 }
 171
 172 #define IMX8_DDR_PMU_EVENT_ATTR(_name, _id)                             \
 173         (&((struct perf_pmu_events_attr[]) {                            \
 174                 { .attr = __ATTR(_name, 0444, ddr_pmu_event_show, NULL),\
 175                   .id = _id, }                                          \
 176         })[0].attr.attr)
 177
 178 static struct attribute *ddr_perf_events_attrs[] = {
 179         IMX8_DDR_PMU_EVENT_ATTR(cycles, EVENT_CYCLES_ID),
 180         IMX8_DDR_PMU_EVENT_ATTR(selfresh, 0x01),
 181         IMX8_DDR_PMU_EVENT_ATTR(read-accesses, 0x04),
 182         IMX8_DDR_PMU_EVENT_ATTR(write-accesses, 0x05),
 183         IMX8_DDR_PMU_EVENT_ATTR(read-queue-depth, 0x08),
 184         IMX8_DDR_PMU_EVENT_ATTR(write-queue-depth, 0x09),
 185         IMX8_DDR_PMU_EVENT_ATTR(lp-read-credit-cnt, 0x10),
 186         IMX8_DDR_PMU_EVENT_ATTR(hp-read-credit-cnt, 0x11),
 187         IMX8_DDR_PMU_EVENT_ATTR(write-credit-cnt, 0x12),
 188         IMX8_DDR_PMU_EVENT_ATTR(read-command, 0x20),
 189         IMX8_DDR_PMU_EVENT_ATTR(write-command, 0x21),
 190         IMX8_DDR_PMU_EVENT_ATTR(read-modify-write-command, 0x22),
 191         IMX8_DDR_PMU_EVENT_ATTR(hp-read, 0x23),
 192         IMX8_DDR_PMU_EVENT_ATTR(hp-req-nocredit, 0x24),
 193         IMX8_DDR_PMU_EVENT_ATTR(hp-xact-credit, 0x25),
 194         IMX8_DDR_PMU_EVENT_ATTR(lp-req-nocredit, 0x26),
 195         IMX8_DDR_PMU_EVENT_ATTR(lp-xact-credit, 0x27),
 196         IMX8_DDR_PMU_EVENT_ATTR(wr-xact-credit, 0x29),
 197         IMX8_DDR_PMU_EVENT_ATTR(read-cycles, 0x2a),
 198         IMX8_DDR_PMU_EVENT_ATTR(write-cycles, 0x2b),
 199         IMX8_DDR_PMU_EVENT_ATTR(read-write-transition, 0x30),
 200         IMX8_DDR_PMU_EVENT_ATTR(precharge, 0x31),
 201         IMX8_DDR_PMU_EVENT_ATTR(activate, 0x32),
 202         IMX8_DDR_PMU_EVENT_ATTR(load-mode, 0x33),
 203         IMX8_DDR_PMU_EVENT_ATTR(perf-mwr, 0x34),
 204         IMX8_DDR_PMU_EVENT_ATTR(read, 0x35),
 205         IMX8_DDR_PMU_EVENT_ATTR(read-activate, 0x36),
 206         IMX8_DDR_PMU_EVENT_ATTR(refresh, 0x37),
 207         IMX8_DDR_PMU_EVENT_ATTR(write, 0x38),
 208         IMX8_DDR_PMU_EVENT_ATTR(raw-hazard, 0x39),
 209         IMX8_DDR_PMU_EVENT_ATTR(axid-read, 0x41),
 210         IMX8_DDR_PMU_EVENT_ATTR(axid-write, 0x42),
 211         NULL,
 212 };
 213
 214 static struct attribute_group ddr_perf_events_attr_group = {
 215         .name = "events",
 216         .attrs = ddr_perf_events_attrs,
 217 };
 218
 219 PMU_FORMAT_ATTR(event, "config:0-7");
 220 PMU_FORMAT_ATTR(axi_id, "config1:0-15");
 221 PMU_FORMAT_ATTR(axi_mask, "config1:16-31");
 222
 223 static struct attribute *ddr_perf_format_attrs[] = {
 224         &format_attr_event.attr,
 225         &format_attr_axi_id.attr,
 226         &format_attr_axi_mask.attr,
 227         NULL,
 228 };
 229
 230 static struct attribute_group ddr_perf_format_attr_group = {
 231         .name = "format",
 232         .attrs = ddr_perf_format_attrs,
 233 };
 234
 235 static const struct attribute_group *attr_groups[] = {
 236         &ddr_perf_events_attr_group,
 237         &ddr_perf_format_attr_group,
 238         &ddr_perf_cpumask_attr_group,
 239         &ddr_perf_filter_cap_attr_group,
 240         NULL,
 241 };
 242
 243 static bool ddr_perf_is_filtered(struct perf_event *event)
 244 {
 245         return event->attr.config == 0x41 || event->attr.config == 0x42;
 246 }
 247
 248 static u32 ddr_perf_filter_val(struct perf_event *event)
 249 {
 250         return event->attr.config1;
 251 }
 252
 253 static bool ddr_perf_filters_compatible(struct perf_event *a,
 254                                         struct perf_event *b)
 255 {
 256         if (!ddr_perf_is_filtered(a))
 257                 return true;
 258         if (!ddr_perf_is_filtered(b))
 259                 return true;
 260         return ddr_perf_filter_val(a) == ddr_perf_filter_val(b);
 261 }
 262
 263 static bool ddr_perf_is_enhanced_filtered(struct perf_event *event)
 264 {
 265         unsigned int filt;
 266         struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
 267
 268         filt = pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER_ENHANCED;
 269         return (filt == DDR_CAP_AXI_ID_FILTER_ENHANCED) &&
 270                 ddr_perf_is_filtered(event);
 271 }
 272
 273 static u32 ddr_perf_alloc_counter(struct ddr_pmu *pmu, int event)
 274 {
 275         int i;
 276
 277         /*
 278          * Always map cycle event to counter 0
 279          * Cycles counter is dedicated for cycle event
 280          * can't used for the other events
 281          */
 282         if (event == EVENT_CYCLES_ID) {
 283                 if (pmu->events[EVENT_CYCLES_COUNTER] == NULL)
 284                         return EVENT_CYCLES_COUNTER;
 285                 else
 286                         return -ENOENT;
 287         }
 288
 289         for (i = 1; i < NUM_COUNTERS; i++) {
 290                 if (pmu->events[i] == NULL)
 291                         return i;
 292         }
 293
 294         return -ENOENT;
 295 }
 296
 297 static void ddr_perf_free_counter(struct ddr_pmu *pmu, int counter)
 298 {
 299         pmu->events[counter] = NULL;
 300 }
 301
 302 static u32 ddr_perf_read_counter(struct ddr_pmu *pmu, int counter)
 303 {
 304         struct perf_event *event = pmu->events[counter];
 305         void __iomem *base = pmu->base;
 306
 307         /*
 308          * return bytes instead of bursts from ddr transaction for
 309          * axid-read and axid-write event if PMU core supports enhanced
 310          * filter.
 311          */
 312         base += ddr_perf_is_enhanced_filtered(event) ? COUNTER_DPCR1 :
 313                                                        COUNTER_READ;
 314         return readl_relaxed(base + counter * 4);
 315 }
 316
 317 static int ddr_perf_event_init(struct perf_event *event)
 318 {
 319         struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
 320         struct hw_perf_event *hwc = &event->hw;
 321         struct perf_event *sibling;
 322
 323         if (event->attr.type != event->pmu->type)
 324                 return -ENOENT;
 325
 326         if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
 327                 return -EOPNOTSUPP;
 328
 329         if (event->cpu < 0) {
 330                 dev_warn(pmu->dev, "Can't provide per-task data!\n");
 331                 return -EOPNOTSUPP;
 332         }
 333
 334         /*
 335          * We must NOT create groups containing mixed PMUs, although software
 336          * events are acceptable (for example to create a CCN group
 337          * periodically read when a hrtimer aka cpu-clock leader triggers).
 338          */
 339         if (event->group_leader->pmu != event->pmu &&
 340                         !is_software_event(event->group_leader))
 341                 return -EINVAL;
 342
 343         if (pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER) {
 344                 if (!ddr_perf_filters_compatible(event, event->group_leader))
 345                         return -EINVAL;
 346                 for_each_sibling_event(sibling, event->group_leader) {
 347                         if (!ddr_perf_filters_compatible(event, sibling))
 348                                 return -EINVAL;
 349                 }
 350         }
 351
 352         for_each_sibling_event(sibling, event->group_leader) {
 353                 if (sibling->pmu != event->pmu &&
 354                                 !is_software_event(sibling))
 355                         return -EINVAL;
 356         }
 357
 358         event->cpu = pmu->cpu;
 359         hwc->idx = -1;
 360
 361         return 0;
 362 }
 363
 364
 365 static void ddr_perf_event_update(struct perf_event *event)
 366 {
 367         struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
 368         struct hw_perf_event *hwc = &event->hw;
 369         u64 delta, prev_raw_count, new_raw_count;
 370         int counter = hwc->idx;
 371
 372         do {
 373                 prev_raw_count = local64_read(&hwc->prev_count);
 374                 new_raw_count = ddr_perf_read_counter(pmu, counter);
 375         } while (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
 376                         new_raw_count) != prev_raw_count);
 377
 378         delta = (new_raw_count - prev_raw_count) & 0xFFFFFFFF;
 379
 380         local64_add(delta, &event->count);
 381 }
 382
 383 static void ddr_perf_counter_enable(struct ddr_pmu *pmu, int config,
 384                                   int counter, bool enable)
 385 {
 386         u8 reg = counter * 4 + COUNTER_CNTL;
 387         int val;
 388
 389         if (enable) {
 390                 /*
 391                  * must disable first, then enable again
 392                  * otherwise, cycle counter will not work
 393                  * if previous state is enabled.
 394                  */
 395                 writel(0, pmu->base + reg);
 396                 val = CNTL_EN | CNTL_CLEAR;
 397                 val |= FIELD_PREP(CNTL_CSV_MASK, config);
 398                 writel(val, pmu->base + reg);
 399         } else {
 400                 /* Disable counter */
 401                 writel(0, pmu->base + reg);
 402         }
 403 }
 404
 405 static void ddr_perf_event_start(struct perf_event *event, int flags)
 406 {
 407         struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
 408         struct hw_perf_event *hwc = &event->hw;
 409         int counter = hwc->idx;
 410
 411         local64_set(&hwc->prev_count, 0);
 412
 413         ddr_perf_counter_enable(pmu, event->attr.config, counter, true);
 414
 415         hwc->state = 0;
 416 }
 417
 418 static int ddr_perf_event_add(struct perf_event *event, int flags)
 419 {
 420         struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
 421         struct hw_perf_event *hwc = &event->hw;
 422         int counter;
 423         int cfg = event->attr.config;
 424         int cfg1 = event->attr.config1;
 425
 426         if (pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER) {
 427                 int i;
 428
 429                 for (i = 1; i < NUM_COUNTERS; i++) {
 430                         if (pmu->events[i] &&
 431                             !ddr_perf_filters_compatible(event, pmu->events[i]))
 432                                 return -EINVAL;
 433                 }
 434
 435                 if (ddr_perf_is_filtered(event)) {
 436                         /* revert axi id masking(axi_mask) value */
 437                         cfg1 ^= AXI_MASKING_REVERT;
 438                         writel(cfg1, pmu->base + COUNTER_DPCR1);
 439                 }
 440         }
 441
 442         counter = ddr_perf_alloc_counter(pmu, cfg);
 443         if (counter < 0) {
 444                 dev_dbg(pmu->dev, "There are not enough counters\n");
 445                 return -EOPNOTSUPP;
 446         }
 447
 448         pmu->events[counter] = event;
 449         pmu->active_events++;
 450         hwc->idx = counter;
 451
 452         hwc->state |= PERF_HES_STOPPED;
 453
 454         if (flags & PERF_EF_START)
 455                 ddr_perf_event_start(event, flags);
 456
 457         return 0;
 458 }
 459
 460 static void ddr_perf_event_stop(struct perf_event *event, int flags)
 461 {
 462         struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
 463         struct hw_perf_event *hwc = &event->hw;
 464         int counter = hwc->idx;
 465
 466         ddr_perf_counter_enable(pmu, event->attr.config, counter, false);
 467         ddr_perf_event_update(event);
 468
 469         hwc->state |= PERF_HES_STOPPED;
 470 }
 471
 472 static void ddr_perf_event_del(struct perf_event *event, int flags)
 473 {
 474         struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
 475         struct hw_perf_event *hwc = &event->hw;
 476         int counter = hwc->idx;
 477
 478         ddr_perf_event_stop(event, PERF_EF_UPDATE);
 479
 480         ddr_perf_free_counter(pmu, counter);
 481         pmu->active_events--;
 482         hwc->idx = -1;
 483 }
 484
 485 static void ddr_perf_pmu_enable(struct pmu *pmu)
 486 {
 487         struct ddr_pmu *ddr_pmu = to_ddr_pmu(pmu);
 488
 489         /* enable cycle counter if cycle is not active event list */
 490         if (ddr_pmu->events[EVENT_CYCLES_COUNTER] == NULL)
 491                 ddr_perf_counter_enable(ddr_pmu,
 492                                       EVENT_CYCLES_ID,
 493                                       EVENT_CYCLES_COUNTER,
 494                                       true);
 495 }
 496
 497 static void ddr_perf_pmu_disable(struct pmu *pmu)
 498 {
 499         struct ddr_pmu *ddr_pmu = to_ddr_pmu(pmu);
 500
 501         if (ddr_pmu->events[EVENT_CYCLES_COUNTER] == NULL)
 502                 ddr_perf_counter_enable(ddr_pmu,
 503                                       EVENT_CYCLES_ID,
 504                                       EVENT_CYCLES_COUNTER,
 505                                       false);
 506 }
 507
 508 static int ddr_perf_init(struct ddr_pmu *pmu, void __iomem *base,
 509                          struct device *dev)
 510 {
 511         *pmu = (struct ddr_pmu) {
 512                 .pmu = (struct pmu) {
 513                         .capabilities = PERF_PMU_CAP_NO_EXCLUDE,
 514                         .task_ctx_nr = perf_invalid_context,
 515                         .attr_groups = attr_groups,
 516                         .event_init  = ddr_perf_event_init,
 517                         .add         = ddr_perf_event_add,
 518                         .del         = ddr_perf_event_del,
 519                         .start       = ddr_perf_event_start,
 520                         .stop        = ddr_perf_event_stop,
 521                         .read        = ddr_perf_event_update,
 522                         .pmu_enable  = ddr_perf_pmu_enable,
 523                         .pmu_disable = ddr_perf_pmu_disable,
 524                 },
 525                 .base = base,
 526                 .dev = dev,
 527         };
 528
 529         pmu->id = ida_simple_get(&ddr_ida, 0, 0, GFP_KERNEL);
 530         return pmu->id;
 531 }
 532
 533 static irqreturn_t ddr_perf_irq_handler(int irq, void *p)
 534 {
 535         int i;
 536         struct ddr_pmu *pmu = (struct ddr_pmu *) p;
 537         struct perf_event *event, *cycle_event = NULL;
 538
 539         /* all counter will stop if cycle counter disabled */
 540         ddr_perf_counter_enable(pmu,
 541                               EVENT_CYCLES_ID,
 542                               EVENT_CYCLES_COUNTER,
 543                               false);
 544         /*
 545          * When the cycle counter overflows, all counters are stopped,
 546          * and an IRQ is raised. If any other counter overflows, it
 547          * continues counting, and no IRQ is raised.
 548          *
 549          * Cycles occur at least 4 times as often as other events, so we
 550          * can update all events on a cycle counter overflow and not
 551          * lose events.
 552          *
 553          */
 554         for (i = 0; i < NUM_COUNTERS; i++) {
 555
 556                 if (!pmu->events[i])
 557                         continue;
 558
 559                 event = pmu->events[i];
 560
 561                 ddr_perf_event_update(event);
 562
 563                 if (event->hw.idx == EVENT_CYCLES_COUNTER)
 564                         cycle_event = event;
 565         }
 566
 567         ddr_perf_counter_enable(pmu,
 568                               EVENT_CYCLES_ID,
 569                               EVENT_CYCLES_COUNTER,
 570                               true);
 571         if (cycle_event)
 572                 ddr_perf_event_update(cycle_event);
 573
 574         return IRQ_HANDLED;
 575 }
 576
 577 static int ddr_perf_offline_cpu(unsigned int cpu, struct hlist_node *node)
 578 {
 579         struct ddr_pmu *pmu = hlist_entry_safe(node, struct ddr_pmu, node);
 580         int target;
 581
 582         if (cpu != pmu->cpu)
 583                 return 0;
 584
 585         target = cpumask_any_but(cpu_online_mask, cpu);
 586         if (target >= nr_cpu_ids)
 587                 return 0;
 588
 589         perf_pmu_migrate_context(&pmu->pmu, cpu, target);
 590         pmu->cpu = target;
 591
 592         WARN_ON(irq_set_affinity_hint(pmu->irq, cpumask_of(pmu->cpu)));
 593
 594         return 0;
 595 }
 596
 597 static int ddr_perf_probe(struct platform_device *pdev)
 598 {
 599         struct ddr_pmu *pmu;
 600         struct device_node *np;
 601         void __iomem *base;
 602         char *name;
 603         int num;
 604         int ret;
 605         int irq;
 606
 607         base = devm_platform_ioremap_resource(pdev, 0);
 608         if (IS_ERR(base))
 609                 return PTR_ERR(base);
 610
 611         np = pdev->dev.of_node;
 612
 613         pmu = devm_kzalloc(&pdev->dev, sizeof(*pmu), GFP_KERNEL);
 614         if (!pmu)
 615                 return -ENOMEM;
 616
 617         num = ddr_perf_init(pmu, base, &pdev->dev);
 618
 619         platform_set_drvdata(pdev, pmu);
 620
 621         name = devm_kasprintf(&pdev->dev, GFP_KERNEL, DDR_PERF_DEV_NAME "%d",
 622                               num);
 623         if (!name)
 624                 return -ENOMEM;
 625
 626         pmu->devtype_data = of_device_get_match_data(&pdev->dev);
 627
 628         pmu->cpu = raw_smp_processor_id();
 629         ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
 630                                       DDR_CPUHP_CB_NAME,
 631                                       NULL,
 632                                       ddr_perf_offline_cpu);
 633
 634         if (ret < 0) {
 635                 dev_err(&pdev->dev, "cpuhp_setup_state_multi failed\n");
 636                 goto cpuhp_state_err;
 637         }
 638
 639         pmu->cpuhp_state = ret;
 640
 641         /* Register the pmu instance for cpu hotplug */
 642         ret = cpuhp_state_add_instance_nocalls(pmu->cpuhp_state, &pmu->node);
 643         if (ret) {
 644                 dev_err(&pdev->dev, "Error %d registering hotplug\n", ret);
 645                 goto cpuhp_instance_err;
 646         }
 647
 648         /* Request irq */
 649         irq = of_irq_get(np, 0);
 650         if (irq < 0) {
 651                 dev_err(&pdev->dev, "Failed to get irq: %d", irq);
 652                 ret = irq;
 653                 goto ddr_perf_err;
 654         }
 655
 656         ret = devm_request_irq(&pdev->dev, irq,
 657                                         ddr_perf_irq_handler,
 658                                         IRQF_NOBALANCING | IRQF_NO_THREAD,
 659                                         DDR_CPUHP_CB_NAME,
 660                                         pmu);
 661         if (ret < 0) {
 662                 dev_err(&pdev->dev, "Request irq failed: %d", ret);
 663                 goto ddr_perf_err;
 664         }
 665
 666         pmu->irq = irq;
 667         ret = irq_set_affinity_hint(pmu->irq, cpumask_of(pmu->cpu));
 668         if (ret) {
 669                 dev_err(pmu->dev, "Failed to set interrupt affinity!\n");
 670                 goto ddr_perf_err;
 671         }
 672
 673         ret = perf_pmu_register(&pmu->pmu, name, -1);
 674         if (ret)
 675                 goto ddr_perf_err;
 676
 677         return 0;
 678
 679 ddr_perf_err:
 680         cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
 681 cpuhp_instance_err:
 682         cpuhp_remove_multi_state(pmu->cpuhp_state);
 683 cpuhp_state_err:
 684         ida_simple_remove(&ddr_ida, pmu->id);
 685         dev_warn(&pdev->dev, "i.MX8 DDR Perf PMU failed (%d), disabled\n", ret);
 686         return ret;
 687 }
 688
 689 static int ddr_perf_remove(struct platform_device *pdev)
 690 {
 691         struct ddr_pmu *pmu = platform_get_drvdata(pdev);
 692
 693         cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
 694         cpuhp_remove_multi_state(pmu->cpuhp_state);
 695         irq_set_affinity_hint(pmu->irq, NULL);
 696
 697         perf_pmu_unregister(&pmu->pmu);
 698
 699         ida_simple_remove(&ddr_ida, pmu->id);
 700         return 0;
 701 }
 702
 703 static struct platform_driver imx_ddr_pmu_driver = {
 704         .driver         = {
 705                 .name   = "imx-ddr-pmu",
 706                 .of_match_table = imx_ddr_pmu_dt_ids,
 707         },
 708         .probe          = ddr_perf_probe,
 709         .remove         = ddr_perf_remove,
 710 };
 711
 712 module_platform_driver(imx_ddr_pmu_driver);
 713 MODULE_LICENSE("GPL v2");