drivers/perf/arm_dmc620_pmu.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * ARM DMC-620 memory controller PMU driver
   4  *
   5  * Copyright (C) 2020 Ampere Computing LLC.
   6  */
   7
   8 #define DMC620_PMUNAME          "arm_dmc620"
   9 #define DMC620_DRVNAME          DMC620_PMUNAME "_pmu"
  10 #define pr_fmt(fmt)             DMC620_DRVNAME ": " fmt
  11
  12 #include <linux/acpi.h>
  13 #include <linux/bitfield.h>
  14 #include <linux/bitops.h>
  15 #include <linux/cpuhotplug.h>
  16 #include <linux/cpumask.h>
  17 #include <linux/device.h>
  18 #include <linux/errno.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/irq.h>
  21 #include <linux/kernel.h>
  22 #include <linux/list.h>
  23 #include <linux/module.h>
  24 #include <linux/mutex.h>
  25 #include <linux/perf_event.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/printk.h>
  28 #include <linux/rculist.h>
  29 #include <linux/refcount.h>
  30
  31 #define DMC620_PA_SHIFT                                 12
  32 #define DMC620_CNT_INIT                                 0x80000000
  33 #define DMC620_CNT_MAX_PERIOD                           0xffffffff
  34 #define DMC620_PMU_CLKDIV2_MAX_COUNTERS                 8
  35 #define DMC620_PMU_CLK_MAX_COUNTERS                     2
  36 #define DMC620_PMU_MAX_COUNTERS                         \
  37         (DMC620_PMU_CLKDIV2_MAX_COUNTERS + DMC620_PMU_CLK_MAX_COUNTERS)
  38
  39 /*
  40  * The PMU registers start at 0xA00 in the DMC-620 memory map, and these
  41  * offsets are relative to that base.
  42  *
  43  * Each counter has a group of control/value registers, and the
  44  * DMC620_PMU_COUNTERn offsets are within a counter group.
  45  *
  46  * The counter registers groups start at 0xA10.
  47  */
  48 #define DMC620_PMU_OVERFLOW_STATUS_CLKDIV2              0x8
  49 #define  DMC620_PMU_OVERFLOW_STATUS_CLKDIV2_MASK        \
  50                 (DMC620_PMU_CLKDIV2_MAX_COUNTERS - 1)
  51 #define DMC620_PMU_OVERFLOW_STATUS_CLK                  0xC
  52 #define  DMC620_PMU_OVERFLOW_STATUS_CLK_MASK            \
  53                 (DMC620_PMU_CLK_MAX_COUNTERS - 1)
  54 #define DMC620_PMU_COUNTERS_BASE                        0x10
  55 #define DMC620_PMU_COUNTERn_MASK_31_00                  0x0
  56 #define DMC620_PMU_COUNTERn_MASK_63_32                  0x4
  57 #define DMC620_PMU_COUNTERn_MATCH_31_00                 0x8
  58 #define DMC620_PMU_COUNTERn_MATCH_63_32                 0xC
  59 #define DMC620_PMU_COUNTERn_CONTROL                     0x10
  60 #define  DMC620_PMU_COUNTERn_CONTROL_ENABLE             BIT(0)
  61 #define  DMC620_PMU_COUNTERn_CONTROL_INVERT             BIT(1)
  62 #define  DMC620_PMU_COUNTERn_CONTROL_EVENT_MUX          GENMASK(6, 2)
  63 #define  DMC620_PMU_COUNTERn_CONTROL_INCR_MUX           GENMASK(8, 7)
  64 #define DMC620_PMU_COUNTERn_VALUE                       0x20
  65 /* Offset of the registers for a given counter, relative to 0xA00 */
  66 #define DMC620_PMU_COUNTERn_OFFSET(n) \
  67         (DMC620_PMU_COUNTERS_BASE + 0x28 * (n))
  68
  69 /*
  70  * dmc620_pmu_irqs_lock: protects dmc620_pmu_irqs list
  71  * dmc620_pmu_node_lock: protects pmus_node lists in all dmc620_pmu instances
  72  */
  73 static DEFINE_MUTEX(dmc620_pmu_irqs_lock);
  74 static DEFINE_MUTEX(dmc620_pmu_node_lock);
  75 static LIST_HEAD(dmc620_pmu_irqs);
  76
  77 struct dmc620_pmu_irq {
  78         struct hlist_node node;
  79         struct list_head pmus_node;
  80         struct list_head irqs_node;
  81         refcount_t refcount;
  82         unsigned int irq_num;
  83         unsigned int cpu;
  84 };
  85
  86 struct dmc620_pmu {
  87         struct pmu pmu;
  88
  89         void __iomem *base;
  90         struct dmc620_pmu_irq *irq;
  91         struct list_head pmus_node;
  92
  93         /*
  94          * We put all clkdiv2 and clk counters to a same array.
  95          * The first DMC620_PMU_CLKDIV2_MAX_COUNTERS bits belong to
  96          * clkdiv2 counters, the last DMC620_PMU_CLK_MAX_COUNTERS
  97          * belong to clk counters.
  98          */
  99         DECLARE_BITMAP(used_mask, DMC620_PMU_MAX_COUNTERS);
 100         struct perf_event *events[DMC620_PMU_MAX_COUNTERS];
 101 };
 102
 103 #define to_dmc620_pmu(p) (container_of(p, struct dmc620_pmu, pmu))
 104
 105 static int cpuhp_state_num;
 106
 107 struct dmc620_pmu_event_attr {
 108         struct device_attribute attr;
 109         u8 clkdiv2;
 110         u8 eventid;
 111 };
 112
 113 static ssize_t
 114 dmc620_pmu_event_show(struct device *dev,
 115                            struct device_attribute *attr, char *page)
 116 {
 117         struct dmc620_pmu_event_attr *eattr;
 118
 119         eattr = container_of(attr, typeof(*eattr), attr);
 120
 121         return sysfs_emit(page, "event=0x%x,clkdiv2=0x%x\n", eattr->eventid, eattr->clkdiv2);
 122 }
 123
 124 #define DMC620_PMU_EVENT_ATTR(_name, _eventid, _clkdiv2)                \
 125         (&((struct dmc620_pmu_event_attr[]) {{                          \
 126                 .attr = __ATTR(_name, 0444, dmc620_pmu_event_show, NULL),       \
 127                 .clkdiv2 = _clkdiv2,                                            \
 128                 .eventid = _eventid,                                    \
 129         }})[0].attr.attr)
 130
 131 static struct attribute *dmc620_pmu_events_attrs[] = {
 132         /* clkdiv2 events list */
 133         DMC620_PMU_EVENT_ATTR(clkdiv2_cycle_count, 0x0, 1),
 134         DMC620_PMU_EVENT_ATTR(clkdiv2_allocate, 0x1, 1),
 135         DMC620_PMU_EVENT_ATTR(clkdiv2_queue_depth, 0x2, 1),
 136         DMC620_PMU_EVENT_ATTR(clkdiv2_waiting_for_wr_data, 0x3, 1),
 137         DMC620_PMU_EVENT_ATTR(clkdiv2_read_backlog, 0x4, 1),
 138         DMC620_PMU_EVENT_ATTR(clkdiv2_waiting_for_mi, 0x5, 1),
 139         DMC620_PMU_EVENT_ATTR(clkdiv2_hazard_resolution, 0x6, 1),
 140         DMC620_PMU_EVENT_ATTR(clkdiv2_enqueue, 0x7, 1),
 141         DMC620_PMU_EVENT_ATTR(clkdiv2_arbitrate, 0x8, 1),
 142         DMC620_PMU_EVENT_ATTR(clkdiv2_lrank_turnaround_activate, 0x9, 1),
 143         DMC620_PMU_EVENT_ATTR(clkdiv2_prank_turnaround_activate, 0xa, 1),
 144         DMC620_PMU_EVENT_ATTR(clkdiv2_read_depth, 0xb, 1),
 145         DMC620_PMU_EVENT_ATTR(clkdiv2_write_depth, 0xc, 1),
 146         DMC620_PMU_EVENT_ATTR(clkdiv2_highigh_qos_depth, 0xd, 1),
 147         DMC620_PMU_EVENT_ATTR(clkdiv2_high_qos_depth, 0xe, 1),
 148         DMC620_PMU_EVENT_ATTR(clkdiv2_medium_qos_depth, 0xf, 1),
 149         DMC620_PMU_EVENT_ATTR(clkdiv2_low_qos_depth, 0x10, 1),
 150         DMC620_PMU_EVENT_ATTR(clkdiv2_activate, 0x11, 1),
 151         DMC620_PMU_EVENT_ATTR(clkdiv2_rdwr, 0x12, 1),
 152         DMC620_PMU_EVENT_ATTR(clkdiv2_refresh, 0x13, 1),
 153         DMC620_PMU_EVENT_ATTR(clkdiv2_training_request, 0x14, 1),
 154         DMC620_PMU_EVENT_ATTR(clkdiv2_t_mac_tracker, 0x15, 1),
 155         DMC620_PMU_EVENT_ATTR(clkdiv2_bk_fsm_tracker, 0x16, 1),
 156         DMC620_PMU_EVENT_ATTR(clkdiv2_bk_open_tracker, 0x17, 1),
 157         DMC620_PMU_EVENT_ATTR(clkdiv2_ranks_in_pwr_down, 0x18, 1),
 158         DMC620_PMU_EVENT_ATTR(clkdiv2_ranks_in_sref, 0x19, 1),
 159
 160         /* clk events list */
 161         DMC620_PMU_EVENT_ATTR(clk_cycle_count, 0x0, 0),
 162         DMC620_PMU_EVENT_ATTR(clk_request, 0x1, 0),
 163         DMC620_PMU_EVENT_ATTR(clk_upload_stall, 0x2, 0),
 164         NULL,
 165 };
 166
 167 static const struct attribute_group dmc620_pmu_events_attr_group = {
 168         .name = "events",
 169         .attrs = dmc620_pmu_events_attrs,
 170 };
 171
 172 /* User ABI */
 173 #define ATTR_CFG_FLD_mask_CFG           config
 174 #define ATTR_CFG_FLD_mask_LO            0
 175 #define ATTR_CFG_FLD_mask_HI            44
 176 #define ATTR_CFG_FLD_match_CFG          config1
 177 #define ATTR_CFG_FLD_match_LO           0
 178 #define ATTR_CFG_FLD_match_HI           44
 179 #define ATTR_CFG_FLD_invert_CFG         config2
 180 #define ATTR_CFG_FLD_invert_LO          0
 181 #define ATTR_CFG_FLD_invert_HI          0
 182 #define ATTR_CFG_FLD_incr_CFG           config2
 183 #define ATTR_CFG_FLD_incr_LO            1
 184 #define ATTR_CFG_FLD_incr_HI            2
 185 #define ATTR_CFG_FLD_event_CFG          config2
 186 #define ATTR_CFG_FLD_event_LO           3
 187 #define ATTR_CFG_FLD_event_HI           8
 188 #define ATTR_CFG_FLD_clkdiv2_CFG        config2
 189 #define ATTR_CFG_FLD_clkdiv2_LO         9
 190 #define ATTR_CFG_FLD_clkdiv2_HI         9
 191
 192 #define __GEN_PMU_FORMAT_ATTR(cfg, lo, hi)                      \
 193         (lo) == (hi) ? #cfg ":" #lo "\n" : #cfg ":" #lo "-" #hi
 194
 195 #define _GEN_PMU_FORMAT_ATTR(cfg, lo, hi)                       \
 196         __GEN_PMU_FORMAT_ATTR(cfg, lo, hi)
 197
 198 #define GEN_PMU_FORMAT_ATTR(name)                               \
 199         PMU_FORMAT_ATTR(name,                                   \
 200         _GEN_PMU_FORMAT_ATTR(ATTR_CFG_FLD_##name##_CFG,         \
 201                              ATTR_CFG_FLD_##name##_LO,          \
 202                              ATTR_CFG_FLD_##name##_HI))
 203
 204 #define _ATTR_CFG_GET_FLD(attr, cfg, lo, hi)                    \
 205         ((((attr)->cfg) >> lo) & GENMASK_ULL(hi - lo, 0))
 206
 207 #define ATTR_CFG_GET_FLD(attr, name)                            \
 208         _ATTR_CFG_GET_FLD(attr,                                 \
 209                           ATTR_CFG_FLD_##name##_CFG,            \
 210                           ATTR_CFG_FLD_##name##_LO,             \
 211                           ATTR_CFG_FLD_##name##_HI)
 212
 213 GEN_PMU_FORMAT_ATTR(mask);
 214 GEN_PMU_FORMAT_ATTR(match);
 215 GEN_PMU_FORMAT_ATTR(invert);
 216 GEN_PMU_FORMAT_ATTR(incr);
 217 GEN_PMU_FORMAT_ATTR(event);
 218 GEN_PMU_FORMAT_ATTR(clkdiv2);
 219
 220 static struct attribute *dmc620_pmu_formats_attrs[] = {
 221         &format_attr_mask.attr,
 222         &format_attr_match.attr,
 223         &format_attr_invert.attr,
 224         &format_attr_incr.attr,
 225         &format_attr_event.attr,
 226         &format_attr_clkdiv2.attr,
 227         NULL,
 228 };
 229
 230 static const struct attribute_group dmc620_pmu_format_attr_group = {
 231         .name   = "format",
 232         .attrs  = dmc620_pmu_formats_attrs,
 233 };
 234
 235 static ssize_t dmc620_pmu_cpumask_show(struct device *dev,
 236                                        struct device_attribute *attr, char *buf)
 237 {
 238         struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(dev_get_drvdata(dev));
 239
 240         return cpumap_print_to_pagebuf(true, buf,
 241                                        cpumask_of(dmc620_pmu->irq->cpu));
 242 }
 243
 244 static struct device_attribute dmc620_pmu_cpumask_attr =
 245         __ATTR(cpumask, 0444, dmc620_pmu_cpumask_show, NULL);
 246
 247 static struct attribute *dmc620_pmu_cpumask_attrs[] = {
 248         &dmc620_pmu_cpumask_attr.attr,
 249         NULL,
 250 };
 251
 252 static const struct attribute_group dmc620_pmu_cpumask_attr_group = {
 253         .attrs = dmc620_pmu_cpumask_attrs,
 254 };
 255
 256 static const struct attribute_group *dmc620_pmu_attr_groups[] = {
 257         &dmc620_pmu_events_attr_group,
 258         &dmc620_pmu_format_attr_group,
 259         &dmc620_pmu_cpumask_attr_group,
 260         NULL,
 261 };
 262
 263 static inline
 264 u32 dmc620_pmu_creg_read(struct dmc620_pmu *dmc620_pmu,
 265                         unsigned int idx, unsigned int reg)
 266 {
 267         return readl(dmc620_pmu->base + DMC620_PMU_COUNTERn_OFFSET(idx) + reg);
 268 }
 269
 270 static inline
 271 void dmc620_pmu_creg_write(struct dmc620_pmu *dmc620_pmu,
 272                         unsigned int idx, unsigned int reg, u32 val)
 273 {
 274         writel(val, dmc620_pmu->base + DMC620_PMU_COUNTERn_OFFSET(idx) + reg);
 275 }
 276
 277 static
 278 unsigned int dmc620_event_to_counter_control(struct perf_event *event)
 279 {
 280         struct perf_event_attr *attr = &event->attr;
 281         unsigned int reg = 0;
 282
 283         reg |= FIELD_PREP(DMC620_PMU_COUNTERn_CONTROL_INVERT,
 284                         ATTR_CFG_GET_FLD(attr, invert));
 285         reg |= FIELD_PREP(DMC620_PMU_COUNTERn_CONTROL_EVENT_MUX,
 286                         ATTR_CFG_GET_FLD(attr, event));
 287         reg |= FIELD_PREP(DMC620_PMU_COUNTERn_CONTROL_INCR_MUX,
 288                         ATTR_CFG_GET_FLD(attr, incr));
 289
 290         return reg;
 291 }
 292
 293 static int dmc620_get_event_idx(struct perf_event *event)
 294 {
 295         struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
 296         int idx, start_idx, end_idx;
 297
 298         if (ATTR_CFG_GET_FLD(&event->attr, clkdiv2)) {
 299                 start_idx = 0;
 300                 end_idx = DMC620_PMU_CLKDIV2_MAX_COUNTERS;
 301         } else {
 302                 start_idx = DMC620_PMU_CLKDIV2_MAX_COUNTERS;
 303                 end_idx = DMC620_PMU_MAX_COUNTERS;
 304         }
 305
 306         for (idx = start_idx; idx < end_idx; ++idx) {
 307                 if (!test_and_set_bit(idx, dmc620_pmu->used_mask))
 308                         return idx;
 309         }
 310
 311         /* The counters are all in use. */
 312         return -EAGAIN;
 313 }
 314
 315 static inline
 316 u64 dmc620_pmu_read_counter(struct perf_event *event)
 317 {
 318         struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
 319
 320         return dmc620_pmu_creg_read(dmc620_pmu,
 321                                     event->hw.idx, DMC620_PMU_COUNTERn_VALUE);
 322 }
 323
 324 static void dmc620_pmu_event_update(struct perf_event *event)
 325 {
 326         struct hw_perf_event *hwc = &event->hw;
 327         u64 delta, prev_count, new_count;
 328
 329         do {
 330                 /* We may also be called from the irq handler */
 331                 prev_count = local64_read(&hwc->prev_count);
 332                 new_count = dmc620_pmu_read_counter(event);
 333         } while (local64_cmpxchg(&hwc->prev_count,
 334                         prev_count, new_count) != prev_count);
 335         delta = (new_count - prev_count) & DMC620_CNT_MAX_PERIOD;
 336         local64_add(delta, &event->count);
 337 }
 338
 339 static void dmc620_pmu_event_set_period(struct perf_event *event)
 340 {
 341         struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
 342
 343         local64_set(&event->hw.prev_count, DMC620_CNT_INIT);
 344         dmc620_pmu_creg_write(dmc620_pmu,
 345                               event->hw.idx, DMC620_PMU_COUNTERn_VALUE, DMC620_CNT_INIT);
 346 }
 347
 348 static void dmc620_pmu_enable_counter(struct perf_event *event)
 349 {
 350         struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
 351         u32 reg;
 352
 353         reg = dmc620_event_to_counter_control(event) | DMC620_PMU_COUNTERn_CONTROL_ENABLE;
 354         dmc620_pmu_creg_write(dmc620_pmu,
 355                               event->hw.idx, DMC620_PMU_COUNTERn_CONTROL, reg);
 356 }
 357
 358 static void dmc620_pmu_disable_counter(struct perf_event *event)
 359 {
 360         struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
 361
 362         dmc620_pmu_creg_write(dmc620_pmu,
 363                               event->hw.idx, DMC620_PMU_COUNTERn_CONTROL, 0);
 364 }
 365
 366 static irqreturn_t dmc620_pmu_handle_irq(int irq_num, void *data)
 367 {
 368         struct dmc620_pmu_irq *irq = data;
 369         struct dmc620_pmu *dmc620_pmu;
 370         irqreturn_t ret = IRQ_NONE;
 371
 372         rcu_read_lock();
 373         list_for_each_entry_rcu(dmc620_pmu, &irq->pmus_node, pmus_node) {
 374                 unsigned long status;
 375                 struct perf_event *event;
 376                 unsigned int idx;
 377
 378                 /*
 379                  * HW doesn't provide a control to atomically disable all counters.
 380                  * To prevent race condition (overflow happens while clearing status register),
 381                  * disable all events before continuing
 382                  */
 383                 for (idx = 0; idx < DMC620_PMU_MAX_COUNTERS; idx++) {
 384                         event = dmc620_pmu->events[idx];
 385                         if (!event)
 386                                 continue;
 387                         dmc620_pmu_disable_counter(event);
 388                 }
 389
 390                 status = readl(dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLKDIV2);
 391                 status |= (readl(dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLK) <<
 392                                 DMC620_PMU_CLKDIV2_MAX_COUNTERS);
 393                 if (status) {
 394                         for_each_set_bit(idx, &status,
 395                                         DMC620_PMU_MAX_COUNTERS) {
 396                                 event = dmc620_pmu->events[idx];
 397                                 if (WARN_ON_ONCE(!event))
 398                                         continue;
 399                                 dmc620_pmu_event_update(event);
 400                                 dmc620_pmu_event_set_period(event);
 401                         }
 402
 403                         if (status & DMC620_PMU_OVERFLOW_STATUS_CLKDIV2_MASK)
 404                                 writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLKDIV2);
 405
 406                         if ((status >> DMC620_PMU_CLKDIV2_MAX_COUNTERS) &
 407                                 DMC620_PMU_OVERFLOW_STATUS_CLK_MASK)
 408                                 writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLK);
 409                 }
 410
 411                 for (idx = 0; idx < DMC620_PMU_MAX_COUNTERS; idx++) {
 412                         event = dmc620_pmu->events[idx];
 413                         if (!event)
 414                                 continue;
 415                         if (!(event->hw.state & PERF_HES_STOPPED))
 416                                 dmc620_pmu_enable_counter(event);
 417                 }
 418
 419                 ret = IRQ_HANDLED;
 420         }
 421         rcu_read_unlock();
 422
 423         return ret;
 424 }
 425
 426 static struct dmc620_pmu_irq *__dmc620_pmu_get_irq(int irq_num)
 427 {
 428         struct dmc620_pmu_irq *irq;
 429         int ret;
 430
 431         list_for_each_entry(irq, &dmc620_pmu_irqs, irqs_node)
 432                 if (irq->irq_num == irq_num && refcount_inc_not_zero(&irq->refcount))
 433                         return irq;
 434
 435         irq = kzalloc(sizeof(*irq), GFP_KERNEL);
 436         if (!irq)
 437                 return ERR_PTR(-ENOMEM);
 438
 439         INIT_LIST_HEAD(&irq->pmus_node);
 440
 441         /* Pick one CPU to be the preferred one to use */
 442         irq->cpu = raw_smp_processor_id();
 443         refcount_set(&irq->refcount, 1);
 444
 445         ret = request_irq(irq_num, dmc620_pmu_handle_irq,
 446                           IRQF_NOBALANCING | IRQF_NO_THREAD,
 447                           "dmc620-pmu", irq);
 448         if (ret)
 449                 goto out_free_aff;
 450
 451         ret = irq_set_affinity(irq_num, cpumask_of(irq->cpu));
 452         if (ret)
 453                 goto out_free_irq;
 454
 455         ret = cpuhp_state_add_instance_nocalls(cpuhp_state_num, &irq->node);
 456         if (ret)
 457                 goto out_free_irq;
 458
 459         irq->irq_num = irq_num;
 460         list_add(&irq->irqs_node, &dmc620_pmu_irqs);
 461
 462         return irq;
 463
 464 out_free_irq:
 465         free_irq(irq_num, irq);
 466 out_free_aff:
 467         kfree(irq);
 468         return ERR_PTR(ret);
 469 }
 470
 471 static int dmc620_pmu_get_irq(struct dmc620_pmu *dmc620_pmu, int irq_num)
 472 {
 473         struct dmc620_pmu_irq *irq;
 474
 475         mutex_lock(&dmc620_pmu_irqs_lock);
 476         irq = __dmc620_pmu_get_irq(irq_num);
 477         mutex_unlock(&dmc620_pmu_irqs_lock);
 478
 479         if (IS_ERR(irq))
 480                 return PTR_ERR(irq);
 481
 482         dmc620_pmu->irq = irq;
 483         mutex_lock(&dmc620_pmu_node_lock);
 484         list_add_rcu(&dmc620_pmu->pmus_node, &irq->pmus_node);
 485         mutex_unlock(&dmc620_pmu_node_lock);
 486
 487         return 0;
 488 }
 489
 490 static void dmc620_pmu_put_irq(struct dmc620_pmu *dmc620_pmu)
 491 {
 492         struct dmc620_pmu_irq *irq = dmc620_pmu->irq;
 493
 494         mutex_lock(&dmc620_pmu_node_lock);
 495         list_del_rcu(&dmc620_pmu->pmus_node);
 496         mutex_unlock(&dmc620_pmu_node_lock);
 497
 498         mutex_lock(&dmc620_pmu_irqs_lock);
 499         if (!refcount_dec_and_test(&irq->refcount)) {
 500                 mutex_unlock(&dmc620_pmu_irqs_lock);
 501                 return;
 502         }
 503
 504         list_del(&irq->irqs_node);
 505         mutex_unlock(&dmc620_pmu_irqs_lock);
 506
 507         free_irq(irq->irq_num, irq);
 508         cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &irq->node);
 509         kfree(irq);
 510 }
 511
 512 static int dmc620_pmu_event_init(struct perf_event *event)
 513 {
 514         struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
 515         struct hw_perf_event *hwc = &event->hw;
 516         struct perf_event *sibling;
 517
 518         if (event->attr.type != event->pmu->type)
 519                 return -ENOENT;
 520
 521         /*
 522          * DMC 620 PMUs are shared across all cpus and cannot
 523          * support task bound and sampling events.
 524          */
 525         if (is_sampling_event(event) ||
 526                 event->attach_state & PERF_ATTACH_TASK) {
 527                 dev_dbg(dmc620_pmu->pmu.dev,
 528                         "Can't support per-task counters\n");
 529                 return -EOPNOTSUPP;
 530         }
 531
 532         /*
 533          * Many perf core operations (eg. events rotation) operate on a
 534          * single CPU context. This is obvious for CPU PMUs, where one
 535          * expects the same sets of events being observed on all CPUs,
 536          * but can lead to issues for off-core PMUs, where each
 537          * event could be theoretically assigned to a different CPU. To
 538          * mitigate this, we enforce CPU assignment to one, selected
 539          * processor.
 540          */
 541         event->cpu = dmc620_pmu->irq->cpu;
 542         if (event->cpu < 0)
 543                 return -EINVAL;
 544
 545         /*
 546          * We can't atomically disable all HW counters so only one event allowed,
 547          * although software events are acceptable.
 548          */
 549         if (event->group_leader != event &&
 550                         !is_software_event(event->group_leader))
 551                 return -EINVAL;
 552
 553         for_each_sibling_event(sibling, event->group_leader) {
 554                 if (sibling != event &&
 555                                 !is_software_event(sibling))
 556                         return -EINVAL;
 557         }
 558
 559         hwc->idx = -1;
 560         return 0;
 561 }
 562
 563 static void dmc620_pmu_read(struct perf_event *event)
 564 {
 565         dmc620_pmu_event_update(event);
 566 }
 567
 568 static void dmc620_pmu_start(struct perf_event *event, int flags)
 569 {
 570         event->hw.state = 0;
 571         dmc620_pmu_event_set_period(event);
 572         dmc620_pmu_enable_counter(event);
 573 }
 574
 575 static void dmc620_pmu_stop(struct perf_event *event, int flags)
 576 {
 577         if (event->hw.state & PERF_HES_STOPPED)
 578                 return;
 579
 580         dmc620_pmu_disable_counter(event);
 581         dmc620_pmu_event_update(event);
 582         event->hw.state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
 583 }
 584
 585 static int dmc620_pmu_add(struct perf_event *event, int flags)
 586 {
 587         struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
 588         struct perf_event_attr *attr = &event->attr;
 589         struct hw_perf_event *hwc = &event->hw;
 590         int idx;
 591         u64 reg;
 592
 593         idx = dmc620_get_event_idx(event);
 594         if (idx < 0)
 595                 return idx;
 596
 597         hwc->idx = idx;
 598         dmc620_pmu->events[idx] = event;
 599         hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
 600
 601         reg = ATTR_CFG_GET_FLD(attr, mask);
 602         dmc620_pmu_creg_write(dmc620_pmu,
 603                               idx, DMC620_PMU_COUNTERn_MASK_31_00, lower_32_bits(reg));
 604         dmc620_pmu_creg_write(dmc620_pmu,
 605                               idx, DMC620_PMU_COUNTERn_MASK_63_32, upper_32_bits(reg));
 606
 607         reg = ATTR_CFG_GET_FLD(attr, match);
 608         dmc620_pmu_creg_write(dmc620_pmu,
 609                               idx, DMC620_PMU_COUNTERn_MATCH_31_00, lower_32_bits(reg));
 610         dmc620_pmu_creg_write(dmc620_pmu,
 611                               idx, DMC620_PMU_COUNTERn_MATCH_63_32, upper_32_bits(reg));
 612
 613         if (flags & PERF_EF_START)
 614                 dmc620_pmu_start(event, PERF_EF_RELOAD);
 615
 616         perf_event_update_userpage(event);
 617         return 0;
 618 }
 619
 620 static void dmc620_pmu_del(struct perf_event *event, int flags)
 621 {
 622         struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
 623         struct hw_perf_event *hwc = &event->hw;
 624         int idx = hwc->idx;
 625
 626         dmc620_pmu_stop(event, PERF_EF_UPDATE);
 627         dmc620_pmu->events[idx] = NULL;
 628         clear_bit(idx, dmc620_pmu->used_mask);
 629         perf_event_update_userpage(event);
 630 }
 631
 632 static int dmc620_pmu_cpu_teardown(unsigned int cpu,
 633                                    struct hlist_node *node)
 634 {
 635         struct dmc620_pmu_irq *irq;
 636         struct dmc620_pmu *dmc620_pmu;
 637         unsigned int target;
 638
 639         irq = hlist_entry_safe(node, struct dmc620_pmu_irq, node);
 640         if (cpu != irq->cpu)
 641                 return 0;
 642
 643         target = cpumask_any_but(cpu_online_mask, cpu);
 644         if (target >= nr_cpu_ids)
 645                 return 0;
 646
 647         /* We're only reading, but this isn't the place to be involving RCU */
 648         mutex_lock(&dmc620_pmu_node_lock);
 649         list_for_each_entry(dmc620_pmu, &irq->pmus_node, pmus_node)
 650                 perf_pmu_migrate_context(&dmc620_pmu->pmu, irq->cpu, target);
 651         mutex_unlock(&dmc620_pmu_node_lock);
 652
 653         WARN_ON(irq_set_affinity(irq->irq_num, cpumask_of(target)));
 654         irq->cpu = target;
 655
 656         return 0;
 657 }
 658
 659 static int dmc620_pmu_device_probe(struct platform_device *pdev)
 660 {
 661         struct dmc620_pmu *dmc620_pmu;
 662         struct resource *res;
 663         char *name;
 664         int irq_num;
 665         int i, ret;
 666
 667         dmc620_pmu = devm_kzalloc(&pdev->dev,
 668                         sizeof(struct dmc620_pmu), GFP_KERNEL);
 669         if (!dmc620_pmu)
 670                 return -ENOMEM;
 671
 672         platform_set_drvdata(pdev, dmc620_pmu);
 673
 674         dmc620_pmu->pmu = (struct pmu) {
 675                 .module = THIS_MODULE,
 676                 .capabilities   = PERF_PMU_CAP_NO_EXCLUDE,
 677                 .task_ctx_nr    = perf_invalid_context,
 678                 .event_init     = dmc620_pmu_event_init,
 679                 .add            = dmc620_pmu_add,
 680                 .del            = dmc620_pmu_del,
 681                 .start          = dmc620_pmu_start,
 682                 .stop           = dmc620_pmu_stop,
 683                 .read           = dmc620_pmu_read,
 684                 .attr_groups    = dmc620_pmu_attr_groups,
 685         };
 686
 687         dmc620_pmu->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
 688         if (IS_ERR(dmc620_pmu->base))
 689                 return PTR_ERR(dmc620_pmu->base);
 690
 691         /* Make sure device is reset before enabling interrupt */
 692         for (i = 0; i < DMC620_PMU_MAX_COUNTERS; i++)
 693                 dmc620_pmu_creg_write(dmc620_pmu, i, DMC620_PMU_COUNTERn_CONTROL, 0);
 694         writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLKDIV2);
 695         writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLK);
 696
 697         irq_num = platform_get_irq(pdev, 0);
 698         if (irq_num < 0)
 699                 return irq_num;
 700
 701         ret = dmc620_pmu_get_irq(dmc620_pmu, irq_num);
 702         if (ret)
 703                 return ret;
 704
 705         name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
 706                                   "%s_%llx", DMC620_PMUNAME,
 707                                   (u64)(res->start >> DMC620_PA_SHIFT));
 708         if (!name) {
 709                 dev_err(&pdev->dev,
 710                           "Create name failed, PMU @%pa\n", &res->start);
 711                 ret = -ENOMEM;
 712                 goto out_teardown_dev;
 713         }
 714
 715         ret = perf_pmu_register(&dmc620_pmu->pmu, name, -1);
 716         if (ret)
 717                 goto out_teardown_dev;
 718
 719         return 0;
 720
 721 out_teardown_dev:
 722         dmc620_pmu_put_irq(dmc620_pmu);
 723         synchronize_rcu();
 724         return ret;
 725 }
 726
 727 static int dmc620_pmu_device_remove(struct platform_device *pdev)
 728 {
 729         struct dmc620_pmu *dmc620_pmu = platform_get_drvdata(pdev);
 730
 731         dmc620_pmu_put_irq(dmc620_pmu);
 732
 733         /* perf will synchronise RCU before devres can free dmc620_pmu */
 734         perf_pmu_unregister(&dmc620_pmu->pmu);
 735
 736         return 0;
 737 }
 738
 739 static const struct acpi_device_id dmc620_acpi_match[] = {
 740         { "ARMHD620", 0},
 741         {},
 742 };
 743 MODULE_DEVICE_TABLE(acpi, dmc620_acpi_match);
 744 static struct platform_driver dmc620_pmu_driver = {
 745         .driver = {
 746                 .name           = DMC620_DRVNAME,
 747                 .acpi_match_table = dmc620_acpi_match,
 748                 .suppress_bind_attrs = true,
 749         },
 750         .probe  = dmc620_pmu_device_probe,
 751         .remove = dmc620_pmu_device_remove,
 752 };
 753
 754 static int __init dmc620_pmu_init(void)
 755 {
 756         int ret;
 757
 758         cpuhp_state_num = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
 759                                       DMC620_DRVNAME,
 760                                       NULL,
 761                                       dmc620_pmu_cpu_teardown);
 762         if (cpuhp_state_num < 0)
 763                 return cpuhp_state_num;
 764
 765         ret = platform_driver_register(&dmc620_pmu_driver);
 766         if (ret)
 767                 cpuhp_remove_multi_state(cpuhp_state_num);
 768
 769         return ret;
 770 }
 771
 772 static void __exit dmc620_pmu_exit(void)
 773 {
 774         platform_driver_unregister(&dmc620_pmu_driver);
 775         cpuhp_remove_multi_state(cpuhp_state_num);
 776 }
 777
 778 module_init(dmc620_pmu_init);
 779 module_exit(dmc620_pmu_exit);
 780
 781 MODULE_DESCRIPTION("Perf driver for the ARM DMC-620 memory controller");
 782 MODULE_AUTHOR("Tuan Phan <tuanphan@os.amperecomputing.com");
 783 MODULE_LICENSE("GPL v2");