arch/nds32/kernel/perf_event

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This source file includes following definitions.
nds32_pmu_map_cache_event
nds32_pmu_map_hw_event
nds32_pmu_map_raw_event
nds32_pmu_map_event
nds32_spav3_map_event
nds32_pfm_getreset_flags
nds32_pfm_has_overflowed
nds32_pfm_counter_has_overflowed
nds32_pmu_event_set_period
nds32_pmu_handle_irq
nds32_pfm_counter_valid
nds32_pfm_disable_counter
nds32_pmu_set_event_filter
nds32_pfm_write_evtsel
nds32_pfm_enable_counter
nds32_pfm_enable_intens
nds32_pfm_disable_intens
event_requires_mode_exclusion
nds32_pmu_enable_event
nds32_pmu_disable_event
nds32_pmu_read_counter
nds32_pmu_write_counter
nds32_pmu_get_event_idx
nds32_pmu_start
nds32_pmu_stop
nds32_pmu_reset
nds32_pmu_init
nds32_read_num_pfm_events
device_pmu_init
probe_current_pmu
nds32_pmu_enable
nds32_pmu_disable
nds32_pmu_release_hardware
nds32_pmu_dispatch_irq
nds32_pmu_reserve_hardware
validate_event
validate_group
__hw_perf_event_init
nds32_pmu_event_init
nds32_start
nds32_pmu_add
nds32_pmu_event_update
nds32_stop
nds32_pmu_del
nds32_pmu_read
nds32_pmu_cpumask_show
nds32_init
nds32_pmu_register
cpu_pmu_get_cpu_events
cpu_pmu_request_irq
cpu_pmu_free_irq
cpu_pmu_init
cpu_pmu_device_probe
register_pmu_driver
unwind_frame_kernel
walk_stackframe
callchain_trace
user_backtrace
user_backtrace_opt_size
perf_callchain_user
perf_callchain_kernel
perf_instruction_pointer
perf_misc_flags
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2008-2017 Andes Technology Corporation
   4  *
   5  * Reference ARMv7: Jean Pihet <jpihet@mvista.com>
   6  * 2010 (c) MontaVista Software, LLC.
   7  */
   8 
   9 #include <linux/perf_event.h>
  10 #include <linux/bitmap.h>
  11 #include <linux/export.h>
  12 #include <linux/kernel.h>
  13 #include <linux/of.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/slab.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/pm_runtime.h>
  18 #include <linux/ftrace.h>
  19 #include <linux/uaccess.h>
  20 #include <linux/sched/clock.h>
  21 #include <linux/percpu-defs.h>
  22 
  23 #include <asm/pmu.h>
  24 #include <asm/irq_regs.h>
  25 #include <asm/nds32.h>
  26 #include <asm/stacktrace.h>
  27 #include <asm/perf_event.h>
  28 #include <nds32_intrinsic.h>
  29 
  30 /* Set at runtime when we know what CPU type we are. */
  31 static struct nds32_pmu *cpu_pmu;
  32 
  33 static DEFINE_PER_CPU(struct pmu_hw_events, cpu_hw_events);
  34 static void nds32_pmu_start(struct nds32_pmu *cpu_pmu);
  35 static void nds32_pmu_stop(struct nds32_pmu *cpu_pmu);
  36 static struct platform_device_id cpu_pmu_plat_device_ids[] = {
  37         {.name = "nds32-pfm"},
  38         {},
  39 };
  40 
  41 static int nds32_pmu_map_cache_event(const unsigned int (*cache_map)
  42                                   [PERF_COUNT_HW_CACHE_MAX]
  43                                   [PERF_COUNT_HW_CACHE_OP_MAX]
  44                                   [PERF_COUNT_HW_CACHE_RESULT_MAX], u64 config)
  45 {
  46         unsigned int cache_type, cache_op, cache_result, ret;
  47 
  48         cache_type = (config >> 0) & 0xff;
  49         if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
  50                 return -EINVAL;
  51 
  52         cache_op = (config >> 8) & 0xff;
  53         if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
  54                 return -EINVAL;
  55 
  56         cache_result = (config >> 16) & 0xff;
  57         if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
  58                 return -EINVAL;
  59 
  60         ret = (int)(*cache_map)[cache_type][cache_op][cache_result];
  61 
  62         if (ret == CACHE_OP_UNSUPPORTED)
  63                 return -ENOENT;
  64 
  65         return ret;
  66 }
  67 
  68 static int
  69 nds32_pmu_map_hw_event(const unsigned int (*event_map)[PERF_COUNT_HW_MAX],
  70                        u64 config)
  71 {
  72         int mapping;
  73 
  74         if (config >= PERF_COUNT_HW_MAX)
  75                 return -ENOENT;
  76 
  77         mapping = (*event_map)[config];
  78         return mapping == HW_OP_UNSUPPORTED ? -ENOENT : mapping;
  79 }
  80 
  81 static int nds32_pmu_map_raw_event(u32 raw_event_mask, u64 config)
  82 {
  83         int ev_type = (int)(config & raw_event_mask);
  84         int idx = config >> 8;
  85 
  86         switch (idx) {
  87         case 0:
  88                 ev_type = PFM_OFFSET_MAGIC_0 + ev_type;
  89                 if (ev_type >= SPAV3_0_SEL_LAST || ev_type <= SPAV3_0_SEL_BASE)
  90                         return -ENOENT;
  91                 break;
  92         case 1:
  93                 ev_type = PFM_OFFSET_MAGIC_1 + ev_type;
  94                 if (ev_type >= SPAV3_1_SEL_LAST || ev_type <= SPAV3_1_SEL_BASE)
  95                         return -ENOENT;
  96                 break;
  97         case 2:
  98                 ev_type = PFM_OFFSET_MAGIC_2 + ev_type;
  99                 if (ev_type >= SPAV3_2_SEL_LAST || ev_type <= SPAV3_2_SEL_BASE)
 100                         return -ENOENT;
 101                 break;
 102         default:
 103                 return -ENOENT;
 104         }
 105 
 106         return ev_type;
 107 }
 108 
 109 int
 110 nds32_pmu_map_event(struct perf_event *event,
 111                     const unsigned int (*event_map)[PERF_COUNT_HW_MAX],
 112                     const unsigned int (*cache_map)
 113                     [PERF_COUNT_HW_CACHE_MAX]
 114                     [PERF_COUNT_HW_CACHE_OP_MAX]
 115                     [PERF_COUNT_HW_CACHE_RESULT_MAX], u32 raw_event_mask)
 116 {
 117         u64 config = event->attr.config;
 118 
 119         switch (event->attr.type) {
 120         case PERF_TYPE_HARDWARE:
 121                 return nds32_pmu_map_hw_event(event_map, config);
 122         case PERF_TYPE_HW_CACHE:
 123                 return nds32_pmu_map_cache_event(cache_map, config);
 124         case PERF_TYPE_RAW:
 125                 return nds32_pmu_map_raw_event(raw_event_mask, config);
 126         }
 127 
 128         return -ENOENT;
 129 }
 130 
 131 static int nds32_spav3_map_event(struct perf_event *event)
 132 {
 133         return nds32_pmu_map_event(event, &nds32_pfm_perf_map,
 134                                 &nds32_pfm_perf_cache_map, SOFTWARE_EVENT_MASK);
 135 }
 136 
 137 static inline u32 nds32_pfm_getreset_flags(void)
 138 {
 139         /* Read overflow status */
 140         u32 val = __nds32__mfsr(NDS32_SR_PFM_CTL);
 141         u32 old_val = val;
 142 
 143         /* Write overflow bit to clear status, and others keep it 0 */
 144         u32 ov_flag = PFM_CTL_OVF[0] | PFM_CTL_OVF[1] | PFM_CTL_OVF[2];
 145 
 146         __nds32__mtsr(val | ov_flag, NDS32_SR_PFM_CTL);
 147 
 148         return old_val;
 149 }
 150 
 151 static inline int nds32_pfm_has_overflowed(u32 pfm)
 152 {
 153         u32 ov_flag = PFM_CTL_OVF[0] | PFM_CTL_OVF[1] | PFM_CTL_OVF[2];
 154 
 155         return pfm & ov_flag;
 156 }
 157 
 158 static inline int nds32_pfm_counter_has_overflowed(u32 pfm, int idx)
 159 {
 160         u32 mask = 0;
 161 
 162         switch (idx) {
 163         case 0:
 164                 mask = PFM_CTL_OVF[0];
 165                 break;
 166         case 1:
 167                 mask = PFM_CTL_OVF[1];
 168                 break;
 169         case 2:
 170                 mask = PFM_CTL_OVF[2];
 171                 break;
 172         default:
 173                 pr_err("%s index wrong\n", __func__);
 174                 break;
 175         }
 176         return pfm & mask;
 177 }
 178 
 179 /*
 180  * Set the next IRQ period, based on the hwc->period_left value.
 181  * To be called with the event disabled in hw:
 182  */
 183 int nds32_pmu_event_set_period(struct perf_event *event)
 184 {
 185         struct nds32_pmu *nds32_pmu = to_nds32_pmu(event->pmu);
 186         struct hw_perf_event *hwc = &event->hw;
 187         s64 left = local64_read(&hwc->period_left);
 188         s64 period = hwc->sample_period;
 189         int ret = 0;
 190 
 191         /* The period may have been changed by PERF_EVENT_IOC_PERIOD */
 192         if (unlikely(period != hwc->last_period))
 193                 left = period - (hwc->last_period - left);
 194 
 195         if (unlikely(left <= -period)) {
 196                 left = period;
 197                 local64_set(&hwc->period_left, left);
 198                 hwc->last_period = period;
 199                 ret = 1;
 200         }
 201 
 202         if (unlikely(left <= 0)) {
 203                 left += period;
 204                 local64_set(&hwc->period_left, left);
 205                 hwc->last_period = period;
 206                 ret = 1;
 207         }
 208 
 209         if (left > (s64)nds32_pmu->max_period)
 210                 left = nds32_pmu->max_period;
 211 
 212         /*
 213          * The hw event starts counting from this event offset,
 214          * mark it to be able to extract future "deltas":
 215          */
 216         local64_set(&hwc->prev_count, (u64)(-left));
 217 
 218         nds32_pmu->write_counter(event, (u64)(-left) & nds32_pmu->max_period);
 219 
 220         perf_event_update_userpage(event);
 221 
 222         return ret;
 223 }
 224 
 225 static irqreturn_t nds32_pmu_handle_irq(int irq_num, void *dev)
 226 {
 227         u32 pfm;
 228         struct perf_sample_data data;
 229         struct nds32_pmu *cpu_pmu = (struct nds32_pmu *)dev;
 230         struct pmu_hw_events *cpuc = cpu_pmu->get_hw_events();
 231         struct pt_regs *regs;
 232         int idx;
 233         /*
 234          * Get and reset the IRQ flags
 235          */
 236         pfm = nds32_pfm_getreset_flags();
 237 
 238         /*
 239          * Did an overflow occur?
 240          */
 241         if (!nds32_pfm_has_overflowed(pfm))
 242                 return IRQ_NONE;
 243 
 244         /*
 245          * Handle the counter(s) overflow(s)
 246          */
 247         regs = get_irq_regs();
 248 
 249         nds32_pmu_stop(cpu_pmu);
 250         for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
 251                 struct perf_event *event = cpuc->events[idx];
 252                 struct hw_perf_event *hwc;
 253 
 254                 /* Ignore if we don't have an event. */
 255                 if (!event)
 256                         continue;
 257 
 258                 /*
 259                  * We have a single interrupt for all counters. Check that
 260                  * each counter has overflowed before we process it.
 261                  */
 262                 if (!nds32_pfm_counter_has_overflowed(pfm, idx))
 263                         continue;
 264 
 265                 hwc = &event->hw;
 266                 nds32_pmu_event_update(event);
 267                 perf_sample_data_init(&data, 0, hwc->last_period);
 268                 if (!nds32_pmu_event_set_period(event))
 269                         continue;
 270 
 271                 if (perf_event_overflow(event, &data, regs))
 272                         cpu_pmu->disable(event);
 273         }
 274         nds32_pmu_start(cpu_pmu);
 275         /*
 276          * Handle the pending perf events.
 277          *
 278          * Note: this call *must* be run with interrupts disabled. For
 279          * platforms that can have the PMU interrupts raised as an NMI, this
 280          * will not work.
 281          */
 282         irq_work_run();
 283 
 284         return IRQ_HANDLED;
 285 }
 286 
 287 static inline int nds32_pfm_counter_valid(struct nds32_pmu *cpu_pmu, int idx)
 288 {
 289         return ((idx >= 0) && (idx < cpu_pmu->num_events));
 290 }
 291 
 292 static inline int nds32_pfm_disable_counter(int idx)
 293 {
 294         unsigned int val = __nds32__mfsr(NDS32_SR_PFM_CTL);
 295         u32 mask = 0;
 296 
 297         mask = PFM_CTL_EN[idx];
 298         val &= ~mask;
 299         val &= ~(PFM_CTL_OVF[0] | PFM_CTL_OVF[1] | PFM_CTL_OVF[2]);
 300         __nds32__mtsr_isb(val, NDS32_SR_PFM_CTL);
 301         return idx;
 302 }
 303 
 304 /*
 305  * Add an event filter to a given event.
 306  */
 307 static int nds32_pmu_set_event_filter(struct hw_perf_event *event,
 308                                       struct perf_event_attr *attr)
 309 {
 310         unsigned long config_base = 0;
 311         int idx = event->idx;
 312         unsigned long no_kernel_tracing = 0;
 313         unsigned long no_user_tracing = 0;
 314         /* If index is -1, do not do anything */
 315         if (idx == -1)
 316                 return 0;
 317 
 318         no_kernel_tracing = PFM_CTL_KS[idx];
 319         no_user_tracing = PFM_CTL_KU[idx];
 320         /*
 321          * Default: enable both kernel and user mode tracing.
 322          */
 323         if (attr->exclude_user)
 324                 config_base |= no_user_tracing;
 325 
 326         if (attr->exclude_kernel)
 327                 config_base |= no_kernel_tracing;
 328 
 329         /*
 330          * Install the filter into config_base as this is used to
 331          * construct the event type.
 332          */
 333         event->config_base |= config_base;
 334         return 0;
 335 }
 336 
 337 static inline void nds32_pfm_write_evtsel(int idx, u32 evnum)
 338 {
 339         u32 offset = 0;
 340         u32 ori_val = __nds32__mfsr(NDS32_SR_PFM_CTL);
 341         u32 ev_mask = 0;
 342         u32 no_kernel_mask = 0;
 343         u32 no_user_mask = 0;
 344         u32 val;
 345 
 346         offset = PFM_CTL_OFFSEL[idx];
 347         /* Clear previous mode selection, and write new one */
 348         no_kernel_mask = PFM_CTL_KS[idx];
 349         no_user_mask = PFM_CTL_KU[idx];
 350         ori_val &= ~no_kernel_mask;
 351         ori_val &= ~no_user_mask;
 352         if (evnum & no_kernel_mask)
 353                 ori_val |= no_kernel_mask;
 354 
 355         if (evnum & no_user_mask)
 356                 ori_val |= no_user_mask;
 357 
 358         /* Clear previous event selection */
 359         ev_mask = PFM_CTL_SEL[idx];
 360         ori_val &= ~ev_mask;
 361         evnum &= SOFTWARE_EVENT_MASK;
 362 
 363         /* undo the linear mapping */
 364         evnum = get_converted_evet_hw_num(evnum);
 365         val = ori_val | (evnum << offset);
 366         val &= ~(PFM_CTL_OVF[0] | PFM_CTL_OVF[1] | PFM_CTL_OVF[2]);
 367         __nds32__mtsr_isb(val, NDS32_SR_PFM_CTL);
 368 }
 369 
 370 static inline int nds32_pfm_enable_counter(int idx)
 371 {
 372         unsigned int val = __nds32__mfsr(NDS32_SR_PFM_CTL);
 373         u32 mask = 0;
 374 
 375         mask = PFM_CTL_EN[idx];
 376         val |= mask;
 377         val &= ~(PFM_CTL_OVF[0] | PFM_CTL_OVF[1] | PFM_CTL_OVF[2]);
 378         __nds32__mtsr_isb(val, NDS32_SR_PFM_CTL);
 379         return idx;
 380 }
 381 
 382 static inline int nds32_pfm_enable_intens(int idx)
 383 {
 384         unsigned int val = __nds32__mfsr(NDS32_SR_PFM_CTL);
 385         u32 mask = 0;
 386 
 387         mask = PFM_CTL_IE[idx];
 388         val |= mask;
 389         val &= ~(PFM_CTL_OVF[0] | PFM_CTL_OVF[1] | PFM_CTL_OVF[2]);
 390         __nds32__mtsr_isb(val, NDS32_SR_PFM_CTL);
 391         return idx;
 392 }
 393 
 394 static inline int nds32_pfm_disable_intens(int idx)
 395 {
 396         unsigned int val = __nds32__mfsr(NDS32_SR_PFM_CTL);
 397         u32 mask = 0;
 398 
 399         mask = PFM_CTL_IE[idx];
 400         val &= ~mask;
 401         val &= ~(PFM_CTL_OVF[0] | PFM_CTL_OVF[1] | PFM_CTL_OVF[2]);
 402         __nds32__mtsr_isb(val, NDS32_SR_PFM_CTL);
 403         return idx;
 404 }
 405 
 406 static int event_requires_mode_exclusion(struct perf_event_attr *attr)
 407 {
 408         /* Other modes NDS32 does not support */
 409         return attr->exclude_user || attr->exclude_kernel;
 410 }
 411 
 412 static void nds32_pmu_enable_event(struct perf_event *event)
 413 {
 414         unsigned long flags;
 415         unsigned int evnum = 0;
 416         struct hw_perf_event *hwc = &event->hw;
 417         struct nds32_pmu *cpu_pmu = to_nds32_pmu(event->pmu);
 418         struct pmu_hw_events *events = cpu_pmu->get_hw_events();
 419         int idx = hwc->idx;
 420 
 421         if (!nds32_pfm_counter_valid(cpu_pmu, idx)) {
 422                 pr_err("CPU enabling wrong pfm counter IRQ enable\n");
 423                 return;
 424         }
 425 
 426         /*
 427          * Enable counter and interrupt, and set the counter to count
 428          * the event that we're interested in.
 429          */
 430         raw_spin_lock_irqsave(&events->pmu_lock, flags);
 431 
 432         /*
 433          * Disable counter
 434          */
 435         nds32_pfm_disable_counter(idx);
 436 
 437         /*
 438          * Check whether we need to exclude the counter from certain modes.
 439          */
 440         if ((!cpu_pmu->set_event_filter ||
 441              cpu_pmu->set_event_filter(hwc, &event->attr)) &&
 442              event_requires_mode_exclusion(&event->attr)) {
 443                 pr_notice
 444                 ("NDS32 performance counters do not support mode exclusion\n");
 445                 hwc->config_base = 0;
 446         }
 447         /* Write event */
 448         evnum = hwc->config_base;
 449         nds32_pfm_write_evtsel(idx, evnum);
 450 
 451         /*
 452          * Enable interrupt for this counter
 453          */
 454         nds32_pfm_enable_intens(idx);
 455 
 456         /*
 457          * Enable counter
 458          */
 459         nds32_pfm_enable_counter(idx);
 460 
 461         raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
 462 }
 463 
 464 static void nds32_pmu_disable_event(struct perf_event *event)
 465 {
 466         unsigned long flags;
 467         struct hw_perf_event *hwc = &event->hw;
 468         struct nds32_pmu *cpu_pmu = to_nds32_pmu(event->pmu);
 469         struct pmu_hw_events *events = cpu_pmu->get_hw_events();
 470         int idx = hwc->idx;
 471 
 472         if (!nds32_pfm_counter_valid(cpu_pmu, idx)) {
 473                 pr_err("CPU disabling wrong pfm counter IRQ enable %d\n", idx);
 474                 return;
 475         }
 476 
 477         /*
 478          * Disable counter and interrupt
 479          */
 480         raw_spin_lock_irqsave(&events->pmu_lock, flags);
 481 
 482         /*
 483          * Disable counter
 484          */
 485         nds32_pfm_disable_counter(idx);
 486 
 487         /*
 488          * Disable interrupt for this counter
 489          */
 490         nds32_pfm_disable_intens(idx);
 491 
 492         raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
 493 }
 494 
 495 static inline u32 nds32_pmu_read_counter(struct perf_event *event)
 496 {
 497         struct nds32_pmu *cpu_pmu = to_nds32_pmu(event->pmu);
 498         struct hw_perf_event *hwc = &event->hw;
 499         int idx = hwc->idx;
 500         u32 count = 0;
 501 
 502         if (!nds32_pfm_counter_valid(cpu_pmu, idx)) {
 503                 pr_err("CPU reading wrong counter %d\n", idx);
 504         } else {
 505                 switch (idx) {
 506                 case PFMC0:
 507                         count = __nds32__mfsr(NDS32_SR_PFMC0);
 508                         break;
 509                 case PFMC1:
 510                         count = __nds32__mfsr(NDS32_SR_PFMC1);
 511                         break;
 512                 case PFMC2:
 513                         count = __nds32__mfsr(NDS32_SR_PFMC2);
 514                         break;
 515                 default:
 516                         pr_err
 517                             ("%s: CPU has no performance counters %d\n",
 518                              __func__, idx);
 519                 }
 520         }
 521         return count;
 522 }
 523 
 524 static inline void nds32_pmu_write_counter(struct perf_event *event, u32 value)
 525 {
 526         struct nds32_pmu *cpu_pmu = to_nds32_pmu(event->pmu);
 527         struct hw_perf_event *hwc = &event->hw;
 528         int idx = hwc->idx;
 529 
 530         if (!nds32_pfm_counter_valid(cpu_pmu, idx)) {
 531                 pr_err("CPU writing wrong counter %d\n", idx);
 532         } else {
 533                 switch (idx) {
 534                 case PFMC0:
 535                         __nds32__mtsr_isb(value, NDS32_SR_PFMC0);
 536                         break;
 537                 case PFMC1:
 538                         __nds32__mtsr_isb(value, NDS32_SR_PFMC1);
 539                         break;
 540                 case PFMC2:
 541                         __nds32__mtsr_isb(value, NDS32_SR_PFMC2);
 542                         break;
 543                 default:
 544                         pr_err
 545                             ("%s: CPU has no performance counters %d\n",
 546                              __func__, idx);
 547                 }
 548         }
 549 }
 550 
 551 static int nds32_pmu_get_event_idx(struct pmu_hw_events *cpuc,
 552                                    struct perf_event *event)
 553 {
 554         int idx;
 555         struct hw_perf_event *hwc = &event->hw;
 556         /*
 557          * Current implementation maps cycles, instruction count and cache-miss
 558          * to specific counter.
 559          * However, multiple of the 3 counters are able to count these events.
 560          *
 561          *
 562          * SOFTWARE_EVENT_MASK mask for getting event num ,
 563          * This is defined by Jia-Rung, you can change the polocies.
 564          * However, do not exceed 8 bits. This is hardware specific.
 565          * The last number is SPAv3_2_SEL_LAST.
 566          */
 567         unsigned long evtype = hwc->config_base & SOFTWARE_EVENT_MASK;
 568 
 569         idx = get_converted_event_idx(evtype);
 570         /*
 571          * Try to get the counter for correpsonding event
 572          */
 573         if (evtype == SPAV3_0_SEL_TOTAL_CYCLES) {
 574                 if (!test_and_set_bit(idx, cpuc->used_mask))
 575                         return idx;
 576                 if (!test_and_set_bit(NDS32_IDX_COUNTER0, cpuc->used_mask))
 577                         return NDS32_IDX_COUNTER0;
 578                 if (!test_and_set_bit(NDS32_IDX_COUNTER1, cpuc->used_mask))
 579                         return NDS32_IDX_COUNTER1;
 580         } else if (evtype == SPAV3_1_SEL_COMPLETED_INSTRUCTION) {
 581                 if (!test_and_set_bit(idx, cpuc->used_mask))
 582                         return idx;
 583                 else if (!test_and_set_bit(NDS32_IDX_COUNTER1, cpuc->used_mask))
 584                         return NDS32_IDX_COUNTER1;
 585                 else if (!test_and_set_bit
 586                          (NDS32_IDX_CYCLE_COUNTER, cpuc->used_mask))
 587                         return NDS32_IDX_CYCLE_COUNTER;
 588         } else {
 589                 if (!test_and_set_bit(idx, cpuc->used_mask))
 590                         return idx;
 591         }
 592         return -EAGAIN;
 593 }
 594 
 595 static void nds32_pmu_start(struct nds32_pmu *cpu_pmu)
 596 {
 597         unsigned long flags;
 598         unsigned int val;
 599         struct pmu_hw_events *events = cpu_pmu->get_hw_events();
 600 
 601         raw_spin_lock_irqsave(&events->pmu_lock, flags);
 602 
 603         /* Enable all counters , NDS PFM has 3 counters */
 604         val = __nds32__mfsr(NDS32_SR_PFM_CTL);
 605         val |= (PFM_CTL_EN[0] | PFM_CTL_EN[1] | PFM_CTL_EN[2]);
 606         val &= ~(PFM_CTL_OVF[0] | PFM_CTL_OVF[1] | PFM_CTL_OVF[2]);
 607         __nds32__mtsr_isb(val, NDS32_SR_PFM_CTL);
 608 
 609         raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
 610 }
 611 
 612 static void nds32_pmu_stop(struct nds32_pmu *cpu_pmu)
 613 {
 614         unsigned long flags;
 615         unsigned int val;
 616         struct pmu_hw_events *events = cpu_pmu->get_hw_events();
 617 
 618         raw_spin_lock_irqsave(&events->pmu_lock, flags);
 619 
 620         /* Disable all counters , NDS PFM has 3 counters */
 621         val = __nds32__mfsr(NDS32_SR_PFM_CTL);
 622         val &= ~(PFM_CTL_EN[0] | PFM_CTL_EN[1] | PFM_CTL_EN[2]);
 623         val &= ~(PFM_CTL_OVF[0] | PFM_CTL_OVF[1] | PFM_CTL_OVF[2]);
 624         __nds32__mtsr_isb(val, NDS32_SR_PFM_CTL);
 625 
 626         raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
 627 }
 628 
 629 static void nds32_pmu_reset(void *info)
 630 {
 631         u32 val = 0;
 632 
 633         val |= (PFM_CTL_OVF[0] | PFM_CTL_OVF[1] | PFM_CTL_OVF[2]);
 634         __nds32__mtsr(val, NDS32_SR_PFM_CTL);
 635         __nds32__mtsr(0, NDS32_SR_PFM_CTL);
 636         __nds32__mtsr(0, NDS32_SR_PFMC0);
 637         __nds32__mtsr(0, NDS32_SR_PFMC1);
 638         __nds32__mtsr(0, NDS32_SR_PFMC2);
 639 }
 640 
 641 static void nds32_pmu_init(struct nds32_pmu *cpu_pmu)
 642 {
 643         cpu_pmu->handle_irq = nds32_pmu_handle_irq;
 644         cpu_pmu->enable = nds32_pmu_enable_event;
 645         cpu_pmu->disable = nds32_pmu_disable_event;
 646         cpu_pmu->read_counter = nds32_pmu_read_counter;
 647         cpu_pmu->write_counter = nds32_pmu_write_counter;
 648         cpu_pmu->get_event_idx = nds32_pmu_get_event_idx;
 649         cpu_pmu->start = nds32_pmu_start;
 650         cpu_pmu->stop = nds32_pmu_stop;
 651         cpu_pmu->reset = nds32_pmu_reset;
 652         cpu_pmu->max_period = 0xFFFFFFFF;       /* Maximum counts */
 653 };
 654 
 655 static u32 nds32_read_num_pfm_events(void)
 656 {
 657         /* NDS32 SPAv3 PMU support 3 counter */
 658         return 3;
 659 }
 660 
 661 static int device_pmu_init(struct nds32_pmu *cpu_pmu)
 662 {
 663         nds32_pmu_init(cpu_pmu);
 664         /*
 665          * This name should be devive-specific name, whatever you like :)
 666          * I think "PMU" will be a good generic name.
 667          */
 668         cpu_pmu->name = "nds32v3-pmu";
 669         cpu_pmu->map_event = nds32_spav3_map_event;
 670         cpu_pmu->num_events = nds32_read_num_pfm_events();
 671         cpu_pmu->set_event_filter = nds32_pmu_set_event_filter;
 672         return 0;
 673 }
 674 
 675 /*
 676  * CPU PMU identification and probing.
 677  */
 678 static int probe_current_pmu(struct nds32_pmu *pmu)
 679 {
 680         int ret;
 681 
 682         get_cpu();
 683         ret = -ENODEV;
 684         /*
 685          * If ther are various CPU types with its own PMU, initialize with
 686          *
 687          * the corresponding one
 688          */
 689         device_pmu_init(pmu);
 690         put_cpu();
 691         return ret;
 692 }
 693 
 694 static void nds32_pmu_enable(struct pmu *pmu)
 695 {
 696         struct nds32_pmu *nds32_pmu = to_nds32_pmu(pmu);
 697         struct pmu_hw_events *hw_events = nds32_pmu->get_hw_events();
 698         int enabled = bitmap_weight(hw_events->used_mask,
 699                                     nds32_pmu->num_events);
 700 
 701         if (enabled)
 702                 nds32_pmu->start(nds32_pmu);
 703 }
 704 
 705 static void nds32_pmu_disable(struct pmu *pmu)
 706 {
 707         struct nds32_pmu *nds32_pmu = to_nds32_pmu(pmu);
 708 
 709         nds32_pmu->stop(nds32_pmu);
 710 }
 711 
 712 static void nds32_pmu_release_hardware(struct nds32_pmu *nds32_pmu)
 713 {
 714         nds32_pmu->free_irq(nds32_pmu);
 715         pm_runtime_put_sync(&nds32_pmu->plat_device->dev);
 716 }
 717 
 718 static irqreturn_t nds32_pmu_dispatch_irq(int irq, void *dev)
 719 {
 720         struct nds32_pmu *nds32_pmu = (struct nds32_pmu *)dev;
 721         int ret;
 722         u64 start_clock, finish_clock;
 723 
 724         start_clock = local_clock();
 725         ret = nds32_pmu->handle_irq(irq, dev);
 726         finish_clock = local_clock();
 727 
 728         perf_sample_event_took(finish_clock - start_clock);
 729         return ret;
 730 }
 731 
 732 static int nds32_pmu_reserve_hardware(struct nds32_pmu *nds32_pmu)
 733 {
 734         int err;
 735         struct platform_device *pmu_device = nds32_pmu->plat_device;
 736 
 737         if (!pmu_device)
 738                 return -ENODEV;
 739 
 740         pm_runtime_get_sync(&pmu_device->dev);
 741         err = nds32_pmu->request_irq(nds32_pmu, nds32_pmu_dispatch_irq);
 742         if (err) {
 743                 nds32_pmu_release_hardware(nds32_pmu);
 744                 return err;
 745         }
 746 
 747         return 0;
 748 }
 749 
 750 static int
 751 validate_event(struct pmu *pmu, struct pmu_hw_events *hw_events,
 752                struct perf_event *event)
 753 {
 754         struct nds32_pmu *nds32_pmu = to_nds32_pmu(event->pmu);
 755 
 756         if (is_software_event(event))
 757                 return 1;
 758 
 759         if (event->pmu != pmu)
 760                 return 0;
 761 
 762         if (event->state < PERF_EVENT_STATE_OFF)
 763                 return 1;
 764 
 765         if (event->state == PERF_EVENT_STATE_OFF && !event->attr.enable_on_exec)
 766                 return 1;
 767 
 768         return nds32_pmu->get_event_idx(hw_events, event) >= 0;
 769 }
 770 
 771 static int validate_group(struct perf_event *event)
 772 {
 773         struct perf_event *sibling, *leader = event->group_leader;
 774         struct pmu_hw_events fake_pmu;
 775         DECLARE_BITMAP(fake_used_mask, MAX_COUNTERS);
 776         /*
 777          * Initialize the fake PMU. We only need to populate the
 778          * used_mask for the purposes of validation.
 779          */
 780         memset(fake_used_mask, 0, sizeof(fake_used_mask));
 781 
 782         if (!validate_event(event->pmu, &fake_pmu, leader))
 783                 return -EINVAL;
 784 
 785         for_each_sibling_event(sibling, leader) {
 786                 if (!validate_event(event->pmu, &fake_pmu, sibling))
 787                         return -EINVAL;
 788         }
 789 
 790         if (!validate_event(event->pmu, &fake_pmu, event))
 791                 return -EINVAL;
 792 
 793         return 0;
 794 }
 795 
 796 static int __hw_perf_event_init(struct perf_event *event)
 797 {
 798         struct nds32_pmu *nds32_pmu = to_nds32_pmu(event->pmu);
 799         struct hw_perf_event *hwc = &event->hw;
 800         int mapping;
 801 
 802         mapping = nds32_pmu->map_event(event);
 803 
 804         if (mapping < 0) {
 805                 pr_debug("event %x:%llx not supported\n", event->attr.type,
 806                          event->attr.config);
 807                 return mapping;
 808         }
 809 
 810         /*
 811          * We don't assign an index until we actually place the event onto
 812          * hardware. Use -1 to signify that we haven't decided where to put it
 813          * yet. For SMP systems, each core has it's own PMU so we can't do any
 814          * clever allocation or constraints checking at this point.
 815          */
 816         hwc->idx = -1;
 817         hwc->config_base = 0;
 818         hwc->config = 0;
 819         hwc->event_base = 0;
 820 
 821         /*
 822          * Check whether we need to exclude the counter from certain modes.
 823          */
 824         if ((!nds32_pmu->set_event_filter ||
 825              nds32_pmu->set_event_filter(hwc, &event->attr)) &&
 826             event_requires_mode_exclusion(&event->attr)) {
 827                 pr_debug
 828                         ("NDS performance counters do not support mode exclusion\n");
 829                 return -EOPNOTSUPP;
 830         }
 831 
 832         /*
 833          * Store the event encoding into the config_base field.
 834          */
 835         hwc->config_base |= (unsigned long)mapping;
 836 
 837         if (!hwc->sample_period) {
 838                 /*
 839                  * For non-sampling runs, limit the sample_period to half
 840                  * of the counter width. That way, the new counter value
 841                  * is far less likely to overtake the previous one unless
 842                  * you have some serious IRQ latency issues.
 843                  */
 844                 hwc->sample_period = nds32_pmu->max_period >> 1;
 845                 hwc->last_period = hwc->sample_period;
 846                 local64_set(&hwc->period_left, hwc->sample_period);
 847         }
 848 
 849         if (event->group_leader != event) {
 850                 if (validate_group(event) != 0)
 851                         return -EINVAL;
 852         }
 853 
 854         return 0;
 855 }
 856 
 857 static int nds32_pmu_event_init(struct perf_event *event)
 858 {
 859         struct nds32_pmu *nds32_pmu = to_nds32_pmu(event->pmu);
 860         int err = 0;
 861         atomic_t *active_events = &nds32_pmu->active_events;
 862 
 863         /* does not support taken branch sampling */
 864         if (has_branch_stack(event))
 865                 return -EOPNOTSUPP;
 866 
 867         if (nds32_pmu->map_event(event) == -ENOENT)
 868                 return -ENOENT;
 869 
 870         if (!atomic_inc_not_zero(active_events)) {
 871                 if (atomic_read(active_events) == 0) {
 872                         /* Register irq handler */
 873                         err = nds32_pmu_reserve_hardware(nds32_pmu);
 874                 }
 875 
 876                 if (!err)
 877                         atomic_inc(active_events);
 878         }
 879 
 880         if (err)
 881                 return err;
 882 
 883         err = __hw_perf_event_init(event);
 884 
 885         return err;
 886 }
 887 
 888 static void nds32_start(struct perf_event *event, int flags)
 889 {
 890         struct nds32_pmu *nds32_pmu = to_nds32_pmu(event->pmu);
 891         struct hw_perf_event *hwc = &event->hw;
 892         /*
 893          * NDS pmu always has to reprogram the period, so ignore
 894          * PERF_EF_RELOAD, see the comment below.
 895          */
 896         if (flags & PERF_EF_RELOAD)
 897                 WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
 898 
 899         hwc->state = 0;
 900         /* Set the period for the event. */
 901         nds32_pmu_event_set_period(event);
 902 
 903         nds32_pmu->enable(event);
 904 }
 905 
 906 static int nds32_pmu_add(struct perf_event *event, int flags)
 907 {
 908         struct nds32_pmu *nds32_pmu = to_nds32_pmu(event->pmu);
 909         struct pmu_hw_events *hw_events = nds32_pmu->get_hw_events();
 910         struct hw_perf_event *hwc = &event->hw;
 911         int idx;
 912         int err = 0;
 913 
 914         perf_pmu_disable(event->pmu);
 915 
 916         /* If we don't have a space for the counter then finish early. */
 917         idx = nds32_pmu->get_event_idx(hw_events, event);
 918         if (idx < 0) {
 919                 err = idx;
 920                 goto out;
 921         }
 922 
 923         /*
 924          * If there is an event in the counter we are going to use then make
 925          * sure it is disabled.
 926          */
 927         event->hw.idx = idx;
 928         nds32_pmu->disable(event);
 929         hw_events->events[idx] = event;
 930 
 931         hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
 932         if (flags & PERF_EF_START)
 933                 nds32_start(event, PERF_EF_RELOAD);
 934 
 935         /* Propagate our changes to the userspace mapping. */
 936         perf_event_update_userpage(event);
 937 
 938 out:
 939         perf_pmu_enable(event->pmu);
 940         return err;
 941 }
 942 
 943 u64 nds32_pmu_event_update(struct perf_event *event)
 944 {
 945         struct nds32_pmu *nds32_pmu = to_nds32_pmu(event->pmu);
 946         struct hw_perf_event *hwc = &event->hw;
 947         u64 delta, prev_raw_count, new_raw_count;
 948 
 949 again:
 950         prev_raw_count = local64_read(&hwc->prev_count);
 951         new_raw_count = nds32_pmu->read_counter(event);
 952 
 953         if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
 954                             new_raw_count) != prev_raw_count) {
 955                 goto again;
 956         }
 957         /*
 958          * Whether overflow or not, "unsigned substraction"
 959          * will always get their delta
 960          */
 961         delta = (new_raw_count - prev_raw_count) & nds32_pmu->max_period;
 962 
 963         local64_add(delta, &event->count);
 964         local64_sub(delta, &hwc->period_left);
 965 
 966         return new_raw_count;
 967 }
 968 
 969 static void nds32_stop(struct perf_event *event, int flags)
 970 {
 971         struct nds32_pmu *nds32_pmu = to_nds32_pmu(event->pmu);
 972         struct hw_perf_event *hwc = &event->hw;
 973         /*
 974          * NDS pmu always has to update the counter, so ignore
 975          * PERF_EF_UPDATE, see comments in nds32_start().
 976          */
 977         if (!(hwc->state & PERF_HES_STOPPED)) {
 978                 nds32_pmu->disable(event);
 979                 nds32_pmu_event_update(event);
 980                 hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
 981         }
 982 }
 983 
 984 static void nds32_pmu_del(struct perf_event *event, int flags)
 985 {
 986         struct nds32_pmu *nds32_pmu = to_nds32_pmu(event->pmu);
 987         struct pmu_hw_events *hw_events = nds32_pmu->get_hw_events();
 988         struct hw_perf_event *hwc = &event->hw;
 989         int idx = hwc->idx;
 990 
 991         nds32_stop(event, PERF_EF_UPDATE);
 992         hw_events->events[idx] = NULL;
 993         clear_bit(idx, hw_events->used_mask);
 994 
 995         perf_event_update_userpage(event);
 996 }
 997 
 998 static void nds32_pmu_read(struct perf_event *event)
 999 {
1000         nds32_pmu_event_update(event);
1001 }
1002 
1003 /* Please refer to SPAv3 for more hardware specific details */
1004 PMU_FORMAT_ATTR(event, "config:0-63");
1005 
1006 static struct attribute *nds32_arch_formats_attr[] = {
1007         &format_attr_event.attr,
1008         NULL,
1009 };
1010 
1011 static struct attribute_group nds32_pmu_format_group = {
1012         .name = "format",
1013         .attrs = nds32_arch_formats_attr,
1014 };
1015 
1016 static ssize_t nds32_pmu_cpumask_show(struct device *dev,
1017                                       struct device_attribute *attr,
1018                                       char *buf)
1019 {
1020         return 0;
1021 }
1022 
1023 static DEVICE_ATTR(cpus, 0444, nds32_pmu_cpumask_show, NULL);
1024 
1025 static struct attribute *nds32_pmu_common_attrs[] = {
1026         &dev_attr_cpus.attr,
1027         NULL,
1028 };
1029 
1030 static struct attribute_group nds32_pmu_common_group = {
1031         .attrs = nds32_pmu_common_attrs,
1032 };
1033 
1034 static const struct attribute_group *nds32_pmu_attr_groups[] = {
1035         &nds32_pmu_format_group,
1036         &nds32_pmu_common_group,
1037         NULL,
1038 };
1039 
1040 static void nds32_init(struct nds32_pmu *nds32_pmu)
1041 {
1042         atomic_set(&nds32_pmu->active_events, 0);
1043 
1044         nds32_pmu->pmu = (struct pmu) {
1045                 .pmu_enable = nds32_pmu_enable,
1046                 .pmu_disable = nds32_pmu_disable,
1047                 .attr_groups = nds32_pmu_attr_groups,
1048                 .event_init = nds32_pmu_event_init,
1049                 .add = nds32_pmu_add,
1050                 .del = nds32_pmu_del,
1051                 .start = nds32_start,
1052                 .stop = nds32_stop,
1053                 .read = nds32_pmu_read,
1054         };
1055 }
1056 
1057 int nds32_pmu_register(struct nds32_pmu *nds32_pmu, int type)
1058 {
1059         nds32_init(nds32_pmu);
1060         pm_runtime_enable(&nds32_pmu->plat_device->dev);
1061         pr_info("enabled with %s PMU driver, %d counters available\n",
1062                 nds32_pmu->name, nds32_pmu->num_events);
1063         return perf_pmu_register(&nds32_pmu->pmu, nds32_pmu->name, type);
1064 }
1065 
1066 static struct pmu_hw_events *cpu_pmu_get_cpu_events(void)
1067 {
1068         return this_cpu_ptr(&cpu_hw_events);
1069 }
1070 
1071 static int cpu_pmu_request_irq(struct nds32_pmu *cpu_pmu, irq_handler_t handler)
1072 {
1073         int err, irq, irqs;
1074         struct platform_device *pmu_device = cpu_pmu->plat_device;
1075 
1076         if (!pmu_device)
1077                 return -ENODEV;
1078 
1079         irqs = min(pmu_device->num_resources, num_possible_cpus());
1080         if (irqs < 1) {
1081                 pr_err("no irqs for PMUs defined\n");
1082                 return -ENODEV;
1083         }
1084 
1085         irq = platform_get_irq(pmu_device, 0);
1086         err = request_irq(irq, handler, IRQF_NOBALANCING, "nds32-pfm",
1087                           cpu_pmu);
1088         if (err) {
1089                 pr_err("unable to request IRQ%d for NDS PMU counters\n",
1090                        irq);
1091                 return err;
1092         }
1093         return 0;
1094 }
1095 
1096 static void cpu_pmu_free_irq(struct nds32_pmu *cpu_pmu)
1097 {
1098         int irq;
1099         struct platform_device *pmu_device = cpu_pmu->plat_device;
1100 
1101         irq = platform_get_irq(pmu_device, 0);
1102         if (irq >= 0)
1103                 free_irq(irq, cpu_pmu);
1104 }
1105 
1106 static void cpu_pmu_init(struct nds32_pmu *cpu_pmu)
1107 {
1108         int cpu;
1109         struct pmu_hw_events *events = &per_cpu(cpu_hw_events, cpu);
1110 
1111         raw_spin_lock_init(&events->pmu_lock);
1112 
1113         cpu_pmu->get_hw_events = cpu_pmu_get_cpu_events;
1114         cpu_pmu->request_irq = cpu_pmu_request_irq;
1115         cpu_pmu->free_irq = cpu_pmu_free_irq;
1116 
1117         /* Ensure the PMU has sane values out of reset. */
1118         if (cpu_pmu->reset)
1119                 on_each_cpu(cpu_pmu->reset, cpu_pmu, 1);
1120 }
1121 
1122 const static struct of_device_id cpu_pmu_of_device_ids[] = {
1123         {.compatible = "andestech,nds32v3-pmu",
1124          .data = device_pmu_init},
1125         {},
1126 };
1127 
1128 static int cpu_pmu_device_probe(struct platform_device *pdev)
1129 {
1130         const struct of_device_id *of_id;
1131         int (*init_fn)(struct nds32_pmu *nds32_pmu);
1132         struct device_node *node = pdev->dev.of_node;
1133         struct nds32_pmu *pmu;
1134         int ret = -ENODEV;
1135 
1136         if (cpu_pmu) {
1137                 pr_notice("[perf] attempt to register multiple PMU devices!\n");
1138                 return -ENOSPC;
1139         }
1140 
1141         pmu = kzalloc(sizeof(*pmu), GFP_KERNEL);
1142         if (!pmu)
1143                 return -ENOMEM;
1144 
1145         of_id = of_match_node(cpu_pmu_of_device_ids, pdev->dev.of_node);
1146         if (node && of_id) {
1147                 init_fn = of_id->data;
1148                 ret = init_fn(pmu);
1149         } else {
1150                 ret = probe_current_pmu(pmu);
1151         }
1152 
1153         if (ret) {
1154                 pr_notice("[perf] failed to probe PMU!\n");
1155                 goto out_free;
1156         }
1157 
1158         cpu_pmu = pmu;
1159         cpu_pmu->plat_device = pdev;
1160         cpu_pmu_init(cpu_pmu);
1161         ret = nds32_pmu_register(cpu_pmu, PERF_TYPE_RAW);
1162 
1163         if (!ret)
1164                 return 0;
1165 
1166 out_free:
1167         pr_notice("[perf] failed to register PMU devices!\n");
1168         kfree(pmu);
1169         return ret;
1170 }
1171 
1172 static struct platform_driver cpu_pmu_driver = {
1173         .driver = {
1174                    .name = "nds32-pfm",
1175                    .of_match_table = cpu_pmu_of_device_ids,
1176                    },
1177         .probe = cpu_pmu_device_probe,
1178         .id_table = cpu_pmu_plat_device_ids,
1179 };
1180 
1181 static int __init register_pmu_driver(void)
1182 {
1183         int err = 0;
1184 
1185         err = platform_driver_register(&cpu_pmu_driver);
1186         if (err)
1187                 pr_notice("[perf] PMU initialization failed\n");
1188         else
1189                 pr_notice("[perf] PMU initialization done\n");
1190 
1191         return err;
1192 }
1193 
1194 device_initcall(register_pmu_driver);
1195 
1196 /*
1197  * References: arch/nds32/kernel/traps.c:__dump()
1198  * You will need to know the NDS ABI first.
1199  */
1200 static int unwind_frame_kernel(struct stackframe *frame)
1201 {
1202         int graph = 0;
1203 #ifdef CONFIG_FRAME_POINTER
1204         /* 0x3 means misalignment */
1205         if (!kstack_end((void *)frame->fp) &&
1206             !((unsigned long)frame->fp & 0x3) &&
1207             ((unsigned long)frame->fp >= TASK_SIZE)) {
1208                 /*
1209                  *      The array index is based on the ABI, the below graph
1210                  *      illustrate the reasons.
1211                  *      Function call procedure: "smw" and "lmw" will always
1212                  *      update SP and FP for you automatically.
1213                  *
1214                  *      Stack                                 Relative Address
1215                  *      |  |                                          0
1216                  *      ----
1217                  *      |LP| <-- SP(before smw)  <-- FP(after smw)   -1
1218                  *      ----
1219                  *      |FP|                                         -2
1220                  *      ----
1221                  *      |  | <-- SP(after smw)                       -3
1222                  */
1223                 frame->lp = ((unsigned long *)frame->fp)[-1];
1224                 frame->fp = ((unsigned long *)frame->fp)[FP_OFFSET];
1225                 /* make sure CONFIG_FUNCTION_GRAPH_TRACER is turned on */
1226                 if (__kernel_text_address(frame->lp))
1227                         frame->lp = ftrace_graph_ret_addr
1228                                                 (NULL, &graph, frame->lp, NULL);
1229 
1230                 return 0;
1231         } else {
1232                 return -EPERM;
1233         }
1234 #else
1235         /*
1236          * You can refer to arch/nds32/kernel/traps.c:__dump()
1237          * Treat "sp" as "fp", but the "sp" is one frame ahead of "fp".
1238          * And, the "sp" is not always correct.
1239          *
1240          *   Stack                                 Relative Address
1241          *   |  |                                          0
1242          *   ----
1243          *   |LP| <-- SP(before smw)                      -1
1244          *   ----
1245          *   |  | <-- SP(after smw)                       -2
1246          *   ----
1247          */
1248         if (!kstack_end((void *)frame->sp)) {
1249                 frame->lp = ((unsigned long *)frame->sp)[1];
1250                 /* TODO: How to deal with the value in first
1251                  * "sp" is not correct?
1252                  */
1253                 if (__kernel_text_address(frame->lp))
1254                         frame->lp = ftrace_graph_ret_addr
1255                                                 (tsk, &graph, frame->lp, NULL);
1256 
1257                 frame->sp = ((unsigned long *)frame->sp) + 1;
1258 
1259                 return 0;
1260         } else {
1261                 return -EPERM;
1262         }
1263 #endif
1264 }
1265 
1266 static void notrace
1267 walk_stackframe(struct stackframe *frame,
1268                 int (*fn_record)(struct stackframe *, void *),
1269                 void *data)
1270 {
1271         while (1) {
1272                 int ret;
1273 
1274                 if (fn_record(frame, data))
1275                         break;
1276 
1277                 ret = unwind_frame_kernel(frame);
1278                 if (ret < 0)
1279                         break;
1280         }
1281 }
1282 
1283 /*
1284  * Gets called by walk_stackframe() for every stackframe. This will be called
1285  * whist unwinding the stackframe and is like a subroutine return so we use
1286  * the PC.
1287  */
1288 static int callchain_trace(struct stackframe *fr, void *data)
1289 {
1290         struct perf_callchain_entry_ctx *entry = data;
1291 
1292         perf_callchain_store(entry, fr->lp);
1293         return 0;
1294 }
1295 
1296 /*
1297  * Get the return address for a single stackframe and return a pointer to the
1298  * next frame tail.
1299  */
1300 static unsigned long
1301 user_backtrace(struct perf_callchain_entry_ctx *entry, unsigned long fp)
1302 {
1303         struct frame_tail buftail;
1304         unsigned long lp = 0;
1305         unsigned long *user_frame_tail =
1306                 (unsigned long *)(fp - (unsigned long)sizeof(buftail));
1307 
1308         /* Check accessibility of one struct frame_tail beyond */
1309         if (!access_ok(user_frame_tail, sizeof(buftail)))
1310                 return 0;
1311         if (__copy_from_user_inatomic
1312                 (&buftail, user_frame_tail, sizeof(buftail)))
1313                 return 0;
1314 
1315         /*
1316          * Refer to unwind_frame_kernel() for more illurstration
1317          */
1318         lp = buftail.stack_lp;  /* ((unsigned long *)fp)[-1] */
1319         fp = buftail.stack_fp;  /* ((unsigned long *)fp)[FP_OFFSET] */
1320         perf_callchain_store(entry, lp);
1321         return fp;
1322 }
1323 
1324 static unsigned long
1325 user_backtrace_opt_size(struct perf_callchain_entry_ctx *entry,
1326                         unsigned long fp)
1327 {
1328         struct frame_tail_opt_size buftail;
1329         unsigned long lp = 0;
1330 
1331         unsigned long *user_frame_tail =
1332                 (unsigned long *)(fp - (unsigned long)sizeof(buftail));
1333 
1334         /* Check accessibility of one struct frame_tail beyond */
1335         if (!access_ok(user_frame_tail, sizeof(buftail)))
1336                 return 0;
1337         if (__copy_from_user_inatomic
1338                 (&buftail, user_frame_tail, sizeof(buftail)))
1339                 return 0;
1340 
1341         /*
1342          * Refer to unwind_frame_kernel() for more illurstration
1343          */
1344         lp = buftail.stack_lp;  /* ((unsigned long *)fp)[-1] */
1345         fp = buftail.stack_fp;  /* ((unsigned long *)fp)[FP_OFFSET] */
1346 
1347         perf_callchain_store(entry, lp);
1348         return fp;
1349 }
1350 
1351 /*
1352  * This will be called when the target is in user mode
1353  * This function will only be called when we use
1354  * "PERF_SAMPLE_CALLCHAIN" in
1355  * kernel/events/core.c:perf_prepare_sample()
1356  *
1357  * How to trigger perf_callchain_[user/kernel] :
1358  * $ perf record -e cpu-clock --call-graph fp ./program
1359  * $ perf report --call-graph
1360  */
1361 unsigned long leaf_fp;
1362 void
1363 perf_callchain_user(struct perf_callchain_entry_ctx *entry,
1364                     struct pt_regs *regs)
1365 {
1366         unsigned long fp = 0;
1367         unsigned long gp = 0;
1368         unsigned long lp = 0;
1369         unsigned long sp = 0;
1370         unsigned long *user_frame_tail;
1371 
1372         leaf_fp = 0;
1373 
1374         if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
1375                 /* We don't support guest os callchain now */
1376                 return;
1377         }
1378 
1379         perf_callchain_store(entry, regs->ipc);
1380         fp = regs->fp;
1381         gp = regs->gp;
1382         lp = regs->lp;
1383         sp = regs->sp;
1384         if (entry->nr < PERF_MAX_STACK_DEPTH &&
1385             (unsigned long)fp && !((unsigned long)fp & 0x7) && fp > sp) {
1386                 user_frame_tail =
1387                         (unsigned long *)(fp - (unsigned long)sizeof(fp));
1388 
1389                 if (!access_ok(user_frame_tail, sizeof(fp)))
1390                         return;
1391 
1392                 if (__copy_from_user_inatomic
1393                         (&leaf_fp, user_frame_tail, sizeof(fp)))
1394                         return;
1395 
1396                 if (leaf_fp == lp) {
1397                         /*
1398                          * Maybe this is non leaf function
1399                          * with optimize for size,
1400                          * or maybe this is the function
1401                          * with optimize for size
1402                          */
1403                         struct frame_tail buftail;
1404 
1405                         user_frame_tail =
1406                                 (unsigned long *)(fp -
1407                                         (unsigned long)sizeof(buftail));
1408 
1409                         if (!access_ok(user_frame_tail, sizeof(buftail)))
1410                                 return;
1411 
1412                         if (__copy_from_user_inatomic
1413                                 (&buftail, user_frame_tail, sizeof(buftail)))
1414                                 return;
1415 
1416                         if (buftail.stack_fp == gp) {
1417                                 /* non leaf function with optimize
1418                                  * for size condition
1419                                  */
1420                                 struct frame_tail_opt_size buftail_opt_size;
1421 
1422                                 user_frame_tail =
1423                                         (unsigned long *)(fp - (unsigned long)
1424                                                 sizeof(buftail_opt_size));
1425 
1426                                 if (!access_ok(user_frame_tail,
1427                                                sizeof(buftail_opt_size)))
1428                                         return;
1429 
1430                                 if (__copy_from_user_inatomic
1431                                    (&buftail_opt_size, user_frame_tail,
1432                                    sizeof(buftail_opt_size)))
1433                                         return;
1434 
1435                                 perf_callchain_store(entry, lp);
1436                                 fp = buftail_opt_size.stack_fp;
1437 
1438                                 while ((entry->nr < PERF_MAX_STACK_DEPTH) &&
1439                                        (unsigned long)fp &&
1440                                                 !((unsigned long)fp & 0x7) &&
1441                                                 fp > sp) {
1442                                         sp = fp;
1443                                         fp = user_backtrace_opt_size(entry, fp);
1444                                 }
1445 
1446                         } else {
1447                                 /* this is the function
1448                                  * without optimize for size
1449                                  */
1450                                 fp = buftail.stack_fp;
1451                                 perf_callchain_store(entry, lp);
1452                                 while ((entry->nr < PERF_MAX_STACK_DEPTH) &&
1453                                        (unsigned long)fp &&
1454                                                 !((unsigned long)fp & 0x7) &&
1455                                                 fp > sp) {
1456                                         sp = fp;
1457                                         fp = user_backtrace(entry, fp);
1458                                 }
1459                         }
1460                 } else {
1461                         /* this is leaf function */
1462                         fp = leaf_fp;
1463                         perf_callchain_store(entry, lp);
1464 
1465                         /* previous function callcahin  */
1466                         while ((entry->nr < PERF_MAX_STACK_DEPTH) &&
1467                                (unsigned long)fp &&
1468                                    !((unsigned long)fp & 0x7) && fp > sp) {
1469                                 sp = fp;
1470                                 fp = user_backtrace(entry, fp);
1471                         }
1472                 }
1473                 return;
1474         }
1475 }
1476 
1477 /* This will be called when the target is in kernel mode */
1478 void
1479 perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
1480                       struct pt_regs *regs)
1481 {
1482         struct stackframe fr;
1483 
1484         if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
1485                 /* We don't support guest os callchain now */
1486                 return;
1487         }
1488         fr.fp = regs->fp;
1489         fr.lp = regs->lp;
1490         fr.sp = regs->sp;
1491         walk_stackframe(&fr, callchain_trace, entry);
1492 }
1493 
1494 unsigned long perf_instruction_pointer(struct pt_regs *regs)
1495 {
1496         /* However, NDS32 does not support virtualization */
1497         if (perf_guest_cbs && perf_guest_cbs->is_in_guest())
1498                 return perf_guest_cbs->get_guest_ip();
1499 
1500         return instruction_pointer(regs);
1501 }
1502 
1503 unsigned long perf_misc_flags(struct pt_regs *regs)
1504 {
1505         int misc = 0;
1506 
1507         /* However, NDS32 does not support virtualization */
1508         if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
1509                 if (perf_guest_cbs->is_user_mode())
1510                         misc |= PERF_RECORD_MISC_GUEST_USER;
1511                 else
1512                         misc |= PERF_RECORD_MISC_GUEST_KERNEL;
1513         } else {
1514                 if (user_mode(regs))
1515                         misc |= PERF_RECORD_MISC_USER;
1516                 else
1517                         misc |= PERF_RECORD_MISC_KERNEL;
1518         }
1519 
1520         return misc;
1521 }
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root/arch/nds32/kernel/perf_event_cpu.c

DEFINITIONS
