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 hwc->idx = -1; 546 547 if (event->group_leader == event) 548 return 0; 549 550 /* 551 * We can't atomically disable all HW counters so only one event allowed, 552 * although software events are acceptable. 553 */ 554 if (!is_software_event(event->group_leader)) 555 return -EINVAL; 556 557 for_each_sibling_event(sibling, event->group_leader) { 558 if (sibling != event && 559 !is_software_event(sibling)) 560 return -EINVAL; 561 } 562 563 return 0; 564 } 565 566 static void dmc620_pmu_read(struct perf_event *event) 567 { 568 dmc620_pmu_event_update(event); 569 } 570 571 static void dmc620_pmu_start(struct perf_event *event, int flags) 572 { 573 event->hw.state = 0; 574 dmc620_pmu_event_set_period(event); 575 dmc620_pmu_enable_counter(event); 576 } 577 578 static void dmc620_pmu_stop(struct perf_event *event, int flags) 579 { 580 if (event->hw.state & PERF_HES_STOPPED) 581 return; 582 583 dmc620_pmu_disable_counter(event); 584 dmc620_pmu_event_update(event); 585 event->hw.state |= PERF_HES_STOPPED | PERF_HES_UPTODATE; 586 } 587 588 static int dmc620_pmu_add(struct perf_event *event, int flags) 589 { 590 struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu); 591 struct perf_event_attr *attr = &event->attr; 592 struct hw_perf_event *hwc = &event->hw; 593 int idx; 594 u64 reg; 595 596 idx = dmc620_get_event_idx(event); 597 if (idx < 0) 598 return idx; 599 600 hwc->idx = idx; 601 dmc620_pmu->events[idx] = event; 602 hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE; 603 604 reg = ATTR_CFG_GET_FLD(attr, mask); 605 dmc620_pmu_creg_write(dmc620_pmu, 606 idx, DMC620_PMU_COUNTERn_MASK_31_00, lower_32_bits(reg)); 607 dmc620_pmu_creg_write(dmc620_pmu, 608 idx, DMC620_PMU_COUNTERn_MASK_63_32, upper_32_bits(reg)); 609 610 reg = ATTR_CFG_GET_FLD(attr, match); 611 dmc620_pmu_creg_write(dmc620_pmu, 612 idx, DMC620_PMU_COUNTERn_MATCH_31_00, lower_32_bits(reg)); 613 dmc620_pmu_creg_write(dmc620_pmu, 614 idx, DMC620_PMU_COUNTERn_MATCH_63_32, upper_32_bits(reg)); 615 616 if (flags & PERF_EF_START) 617 dmc620_pmu_start(event, PERF_EF_RELOAD); 618 619 perf_event_update_userpage(event); 620 return 0; 621 } 622 623 static void dmc620_pmu_del(struct perf_event *event, int flags) 624 { 625 struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu); 626 struct hw_perf_event *hwc = &event->hw; 627 int idx = hwc->idx; 628 629 dmc620_pmu_stop(event, PERF_EF_UPDATE); 630 dmc620_pmu->events[idx] = NULL; 631 clear_bit(idx, dmc620_pmu->used_mask); 632 perf_event_update_userpage(event); 633 } 634 635 static int dmc620_pmu_cpu_teardown(unsigned int cpu, 636 struct hlist_node *node) 637 { 638 struct dmc620_pmu_irq *irq; 639 struct dmc620_pmu *dmc620_pmu; 640 unsigned int target; 641 642 irq = hlist_entry_safe(node, struct dmc620_pmu_irq, node); 643 if (cpu != irq->cpu) 644 return 0; 645 646 target = cpumask_any_but(cpu_online_mask, cpu); 647 if (target >= nr_cpu_ids) 648 return 0; 649 650 /* We're only reading, but this isn't the place to be involving RCU */ 651 mutex_lock(&dmc620_pmu_node_lock); 652 list_for_each_entry(dmc620_pmu, &irq->pmus_node, pmus_node) 653 perf_pmu_migrate_context(&dmc620_pmu->pmu, irq->cpu, target); 654 mutex_unlock(&dmc620_pmu_node_lock); 655 656 WARN_ON(irq_set_affinity(irq->irq_num, cpumask_of(target))); 657 irq->cpu = target; 658 659 return 0; 660 } 661 662 static int dmc620_pmu_device_probe(struct platform_device *pdev) 663 { 664 struct dmc620_pmu *dmc620_pmu; 665 struct resource *res; 666 char *name; 667 int irq_num; 668 int i, ret; 669 670 dmc620_pmu = devm_kzalloc(&pdev->dev, 671 sizeof(struct dmc620_pmu), GFP_KERNEL); 672 if (!dmc620_pmu) 673 return -ENOMEM; 674 675 platform_set_drvdata(pdev, dmc620_pmu); 676 677 dmc620_pmu->pmu = (struct pmu) { 678 .module = THIS_MODULE, 679 .parent = &pdev->dev, 680 .capabilities = PERF_PMU_CAP_NO_EXCLUDE, 681 .task_ctx_nr = perf_invalid_context, 682 .event_init = dmc620_pmu_event_init, 683 .add = dmc620_pmu_add, 684 .del = dmc620_pmu_del, 685 .start = dmc620_pmu_start, 686 .stop = dmc620_pmu_stop, 687 .read = dmc620_pmu_read, 688 .attr_groups = dmc620_pmu_attr_groups, 689 }; 690 691 dmc620_pmu->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 692 if (IS_ERR(dmc620_pmu->base)) 693 return PTR_ERR(dmc620_pmu->base); 694 695 /* Make sure device is reset before enabling interrupt */ 696 for (i = 0; i < DMC620_PMU_MAX_COUNTERS; i++) 697 dmc620_pmu_creg_write(dmc620_pmu, i, DMC620_PMU_COUNTERn_CONTROL, 0); 698 writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLKDIV2); 699 writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLK); 700 701 irq_num = platform_get_irq(pdev, 0); 702 if (irq_num < 0) 703 return irq_num; 704 705 ret = dmc620_pmu_get_irq(dmc620_pmu, irq_num); 706 if (ret) 707 return ret; 708 709 name = devm_kasprintf(&pdev->dev, GFP_KERNEL, 710 "%s_%llx", DMC620_PMUNAME, 711 (u64)(res->start >> DMC620_PA_SHIFT)); 712 if (!name) { 713 dev_err(&pdev->dev, 714 "Create name failed, PMU @%pa\n", &res->start); 715 ret = -ENOMEM; 716 goto out_teardown_dev; 717 } 718 719 ret = perf_pmu_register(&dmc620_pmu->pmu, name, -1); 720 if (ret) 721 goto out_teardown_dev; 722 723 return 0; 724 725 out_teardown_dev: 726 dmc620_pmu_put_irq(dmc620_pmu); 727 synchronize_rcu(); 728 return ret; 729 } 730 731 static void dmc620_pmu_device_remove(struct platform_device *pdev) 732 { 733 struct dmc620_pmu *dmc620_pmu = platform_get_drvdata(pdev); 734 735 dmc620_pmu_put_irq(dmc620_pmu); 736 737 /* perf will synchronise RCU before devres can free dmc620_pmu */ 738 perf_pmu_unregister(&dmc620_pmu->pmu); 739 } 740 741 static const struct acpi_device_id dmc620_acpi_match[] = { 742 { "ARMHD620", 0}, 743 {}, 744 }; 745 MODULE_DEVICE_TABLE(acpi, dmc620_acpi_match); 746 static struct platform_driver dmc620_pmu_driver = { 747 .driver = { 748 .name = DMC620_DRVNAME, 749 .acpi_match_table = dmc620_acpi_match, 750 .suppress_bind_attrs = true, 751 }, 752 .probe = dmc620_pmu_device_probe, 753 .remove_new = dmc620_pmu_device_remove, 754 }; 755 756 static int __init dmc620_pmu_init(void) 757 { 758 int ret; 759 760 cpuhp_state_num = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, 761 DMC620_DRVNAME, 762 NULL, 763 dmc620_pmu_cpu_teardown); 764 if (cpuhp_state_num < 0) 765 return cpuhp_state_num; 766 767 ret = platform_driver_register(&dmc620_pmu_driver); 768 if (ret) 769 cpuhp_remove_multi_state(cpuhp_state_num); 770 771 return ret; 772 } 773 774 static void __exit dmc620_pmu_exit(void) 775 { 776 platform_driver_unregister(&dmc620_pmu_driver); 777 cpuhp_remove_multi_state(cpuhp_state_num); 778 } 779 780 module_init(dmc620_pmu_init); 781 module_exit(dmc620_pmu_exit); 782 783 MODULE_DESCRIPTION("Perf driver for the ARM DMC-620 memory controller"); 784 MODULE_AUTHOR("Tuan Phan <tuanphan@os.amperecomputing.com"); 785 MODULE_LICENSE("GPL v2"); 786