include/linux/perf_event.h

   1 /*
   2  * Performance events:
   3  *
   4  *    Copyright (C) 2008-2009, Thomas Gleixner <[email protected]>
   5  *    Copyright (C) 2008-2011, Red Hat, Inc., Ingo Molnar
   6  *    Copyright (C) 2008-2011, Red Hat, Inc., Peter Zijlstra
   7  *
   8  * Data type definitions, declarations, prototypes.
   9  *
  10  *    Started by: Thomas Gleixner and Ingo Molnar
  11  *
  12  * For licencing details see kernel-base/COPYING
  13  */
  14 #ifndef _LINUX_PERF_EVENT_H
  15 #define _LINUX_PERF_EVENT_H
  16
  17 #include <uapi/linux/perf_event.h>
  18 #include <uapi/linux/bpf_perf_event.h>
  19
  20 /*
  21  * Kernel-internal data types and definitions:
  22  */
  23
  24 #ifdef CONFIG_PERF_EVENTS
  25 # include <asm/perf_event.h>
  26 # include <asm/local64.h>
  27 #endif
  28
  29 #define PERF_GUEST_ACTIVE       0x01
  30 #define PERF_GUEST_USER 0x02
  31
  32 struct perf_guest_info_callbacks {
  33         unsigned int                    (*state)(void);
  34         unsigned long                   (*get_ip)(void);
  35         unsigned int                    (*handle_intel_pt_intr)(void);
  36 };
  37
  38 #ifdef CONFIG_HAVE_HW_BREAKPOINT
  39 #include <linux/rhashtable-types.h>
  40 #include <asm/hw_breakpoint.h>
  41 #endif
  42
  43 #include <linux/list.h>
  44 #include <linux/mutex.h>
  45 #include <linux/rculist.h>
  46 #include <linux/rcupdate.h>
  47 #include <linux/spinlock.h>
  48 #include <linux/hrtimer.h>
  49 #include <linux/fs.h>
  50 #include <linux/pid_namespace.h>
  51 #include <linux/workqueue.h>
  52 #include <linux/ftrace.h>
  53 #include <linux/cpu.h>
  54 #include <linux/irq_work.h>
  55 #include <linux/static_key.h>
  56 #include <linux/jump_label_ratelimit.h>
  57 #include <linux/atomic.h>
  58 #include <linux/sysfs.h>
  59 #include <linux/perf_regs.h>
  60 #include <linux/cgroup.h>
  61 #include <linux/refcount.h>
  62 #include <linux/security.h>
  63 #include <linux/static_call.h>
  64 #include <linux/lockdep.h>
  65 #include <asm/local.h>
  66
  67 struct perf_callchain_entry {
  68         __u64                           nr;
  69         __u64                           ip[]; /* /proc/sys/kernel/perf_event_max_stack */
  70 };
  71
  72 struct perf_callchain_entry_ctx {
  73         struct perf_callchain_entry *entry;
  74         u32                         max_stack;
  75         u32                         nr;
  76         short                       contexts;
  77         bool                        contexts_maxed;
  78 };
  79
  80 typedef unsigned long (*perf_copy_f)(void *dst, const void *src,
  81                                      unsigned long off, unsigned long len);
  82
  83 struct perf_raw_frag {
  84         union {
  85                 struct perf_raw_frag    *next;
  86                 unsigned long           pad;
  87         };
  88         perf_copy_f                     copy;
  89         void                            *data;
  90         u32                             size;
  91 } __packed;
  92
  93 struct perf_raw_record {
  94         struct perf_raw_frag            frag;
  95         u32                             size;
  96 };
  97
  98 static __always_inline bool perf_raw_frag_last(const struct perf_raw_frag *frag)
  99 {
 100         return frag->pad < sizeof(u64);
 101 }
 102
 103 /*
 104  * branch stack layout:
 105  *  nr: number of taken branches stored in entries[]
 106  *  hw_idx: The low level index of raw branch records
 107  *          for the most recent branch.
 108  *          -1ULL means invalid/unknown.
 109  *
 110  * Note that nr can vary from sample to sample
 111  * branches (to, from) are stored from most recent
 112  * to least recent, i.e., entries[0] contains the most
 113  * recent branch.
 114  * The entries[] is an abstraction of raw branch records,
 115  * which may not be stored in age order in HW, e.g. Intel LBR.
 116  * The hw_idx is to expose the low level index of raw
 117  * branch record for the most recent branch aka entries[0].
 118  * The hw_idx index is between -1 (unknown) and max depth,
 119  * which can be retrieved in /sys/devices/cpu/caps/branches.
 120  * For the architectures whose raw branch records are
 121  * already stored in age order, the hw_idx should be 0.
 122  */
 123 struct perf_branch_stack {
 124         __u64                           nr;
 125         __u64                           hw_idx;
 126         struct perf_branch_entry        entries[];
 127 };
 128
 129 struct task_struct;
 130
 131 /*
 132  * extra PMU register associated with an event
 133  */
 134 struct hw_perf_event_extra {
 135         u64             config; /* register value */
 136         unsigned int    reg;    /* register address or index */
 137         int             alloc;  /* extra register already allocated */
 138         int             idx;    /* index in shared_regs->regs[] */
 139 };
 140
 141 /**
 142  * hw_perf_event::flag values
 143  *
 144  * PERF_EVENT_FLAG_ARCH bits are reserved for architecture-specific
 145  * usage.
 146  */
 147 #define PERF_EVENT_FLAG_ARCH                    0x000fffff
 148 #define PERF_EVENT_FLAG_USER_READ_CNT           0x80000000
 149
 150 static_assert((PERF_EVENT_FLAG_USER_READ_CNT & PERF_EVENT_FLAG_ARCH) == 0);
 151
 152 /**
 153  * struct hw_perf_event - performance event hardware details:
 154  */
 155 struct hw_perf_event {
 156 #ifdef CONFIG_PERF_EVENTS
 157         union {
 158                 struct { /* hardware */
 159                         u64             config;
 160                         u64             last_tag;
 161                         unsigned long   config_base;
 162                         unsigned long   event_base;
 163                         int             event_base_rdpmc;
 164                         int             idx;
 165                         int             last_cpu;
 166                         int             flags;
 167
 168                         struct hw_perf_event_extra extra_reg;
 169                         struct hw_perf_event_extra branch_reg;
 170                 };
 171                 struct { /* software */
 172                         struct hrtimer  hrtimer;
 173                 };
 174                 struct { /* tracepoint */
 175                         /* for tp_event->class */
 176                         struct list_head        tp_list;
 177                 };
 178                 struct { /* amd_power */
 179                         u64     pwr_acc;
 180                         u64     ptsc;
 181                 };
 182 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 183                 struct { /* breakpoint */
 184                         /*
 185                          * Crufty hack to avoid the chicken and egg
 186                          * problem hw_breakpoint has with context
 187                          * creation and event initalization.
 188                          */
 189                         struct arch_hw_breakpoint       info;
 190                         struct rhlist_head              bp_list;
 191                 };
 192 #endif
 193                 struct { /* amd_iommu */
 194                         u8      iommu_bank;
 195                         u8      iommu_cntr;
 196                         u16     padding;
 197                         u64     conf;
 198                         u64     conf1;
 199                 };
 200         };
 201         /*
 202          * If the event is a per task event, this will point to the task in
 203          * question. See the comment in perf_event_alloc().
 204          */
 205         struct task_struct              *target;
 206
 207         /*
 208          * PMU would store hardware filter configuration
 209          * here.
 210          */
 211         void                            *addr_filters;
 212
 213         /* Last sync'ed generation of filters */
 214         unsigned long                   addr_filters_gen;
 215
 216 /*
 217  * hw_perf_event::state flags; used to track the PERF_EF_* state.
 218  */
 219 #define PERF_HES_STOPPED        0x01 /* the counter is stopped */
 220 #define PERF_HES_UPTODATE       0x02 /* event->count up-to-date */
 221 #define PERF_HES_ARCH           0x04
 222
 223         int                             state;
 224
 225         /*
 226          * The last observed hardware counter value, updated with a
 227          * local64_cmpxchg() such that pmu::read() can be called nested.
 228          */
 229         local64_t                       prev_count;
 230
 231         /*
 232          * The period to start the next sample with.
 233          */
 234         u64                             sample_period;
 235
 236         union {
 237                 struct { /* Sampling */
 238                         /*
 239                          * The period we started this sample with.
 240                          */
 241                         u64                             last_period;
 242
 243                         /*
 244                          * However much is left of the current period;
 245                          * note that this is a full 64bit value and
 246                          * allows for generation of periods longer
 247                          * than hardware might allow.
 248                          */
 249                         local64_t                       period_left;
 250                 };
 251                 struct { /* Topdown events counting for context switch */
 252                         u64                             saved_metric;
 253                         u64                             saved_slots;
 254                 };
 255         };
 256
 257         /*
 258          * State for throttling the event, see __perf_event_overflow() and
 259          * perf_adjust_freq_unthr_context().
 260          */
 261         u64                             interrupts_seq;
 262         u64                             interrupts;
 263
 264         /*
 265          * State for freq target events, see __perf_event_overflow() and
 266          * perf_adjust_freq_unthr_context().
 267          */
 268         u64                             freq_time_stamp;
 269         u64                             freq_count_stamp;
 270 #endif
 271 };
 272
 273 struct perf_event;
 274 struct perf_event_pmu_context;
 275
 276 /*
 277  * Common implementation detail of pmu::{start,commit,cancel}_txn
 278  */
 279 #define PERF_PMU_TXN_ADD  0x1           /* txn to add/schedule event on PMU */
 280 #define PERF_PMU_TXN_READ 0x2           /* txn to read event group from PMU */
 281
 282 /**
 283  * pmu::capabilities flags
 284  */
 285 #define PERF_PMU_CAP_NO_INTERRUPT               0x0001
 286 #define PERF_PMU_CAP_NO_NMI                     0x0002
 287 #define PERF_PMU_CAP_AUX_NO_SG                  0x0004
 288 #define PERF_PMU_CAP_EXTENDED_REGS              0x0008
 289 #define PERF_PMU_CAP_EXCLUSIVE                  0x0010
 290 #define PERF_PMU_CAP_ITRACE                     0x0020
 291 #define PERF_PMU_CAP_NO_EXCLUDE                 0x0040
 292 #define PERF_PMU_CAP_AUX_OUTPUT                 0x0080
 293 #define PERF_PMU_CAP_EXTENDED_HW_TYPE           0x0100
 294
 295 struct perf_output_handle;
 296
 297 #define PMU_NULL_DEV    ((void *)(~0UL))
 298
 299 /**
 300  * struct pmu - generic performance monitoring unit
 301  */
 302 struct pmu {
 303         struct list_head                entry;
 304
 305         struct module                   *module;
 306         struct device                   *dev;
 307         struct device                   *parent;
 308         const struct attribute_group    **attr_groups;
 309         const struct attribute_group    **attr_update;
 310         const char                      *name;
 311         int                             type;
 312
 313         /*
 314          * various common per-pmu feature flags
 315          */
 316         int                             capabilities;
 317
 318         int __percpu                    *pmu_disable_count;
 319         struct perf_cpu_pmu_context __percpu *cpu_pmu_context;
 320         atomic_t                        exclusive_cnt; /* < 0: cpu; > 0: tsk */
 321         int                             task_ctx_nr;
 322         int                             hrtimer_interval_ms;
 323
 324         /* number of address filters this PMU can do */
 325         unsigned int                    nr_addr_filters;
 326
 327         /*
 328          * Fully disable/enable this PMU, can be used to protect from the PMI
 329          * as well as for lazy/batch writing of the MSRs.
 330          */
 331         void (*pmu_enable)              (struct pmu *pmu); /* optional */
 332         void (*pmu_disable)             (struct pmu *pmu); /* optional */
 333
 334         /*
 335          * Try and initialize the event for this PMU.
 336          *
 337          * Returns:
 338          *  -ENOENT     -- @event is not for this PMU
 339          *
 340          *  -ENODEV     -- @event is for this PMU but PMU not present
 341          *  -EBUSY      -- @event is for this PMU but PMU temporarily unavailable
 342          *  -EINVAL     -- @event is for this PMU but @event is not valid
 343          *  -EOPNOTSUPP -- @event is for this PMU, @event is valid, but not supported
 344          *  -EACCES     -- @event is for this PMU, @event is valid, but no privileges
 345          *
 346          *  0           -- @event is for this PMU and valid
 347          *
 348          * Other error return values are allowed.
 349          */
 350         int (*event_init)               (struct perf_event *event);
 351
 352         /*
 353          * Notification that the event was mapped or unmapped.  Called
 354          * in the context of the mapping task.
 355          */
 356         void (*event_mapped)            (struct perf_event *event, struct mm_struct *mm); /* optional */
 357         void (*event_unmapped)          (struct perf_event *event, struct mm_struct *mm); /* optional */
 358
 359         /*
 360          * Flags for ->add()/->del()/ ->start()/->stop(). There are
 361          * matching hw_perf_event::state flags.
 362          */
 363 #define PERF_EF_START   0x01            /* start the counter when adding    */
 364 #define PERF_EF_RELOAD  0x02            /* reload the counter when starting */
 365 #define PERF_EF_UPDATE  0x04            /* update the counter when stopping */
 366
 367         /*
 368          * Adds/Removes a counter to/from the PMU, can be done inside a
 369          * transaction, see the ->*_txn() methods.
 370          *
 371          * The add/del callbacks will reserve all hardware resources required
 372          * to service the event, this includes any counter constraint
 373          * scheduling etc.
 374          *
 375          * Called with IRQs disabled and the PMU disabled on the CPU the event
 376          * is on.
 377          *
 378          * ->add() called without PERF_EF_START should result in the same state
 379          *  as ->add() followed by ->stop().
 380          *
 381          * ->del() must always PERF_EF_UPDATE stop an event. If it calls
 382          *  ->stop() that must deal with already being stopped without
 383          *  PERF_EF_UPDATE.
 384          */
 385         int  (*add)                     (struct perf_event *event, int flags);
 386         void (*del)                     (struct perf_event *event, int flags);
 387
 388         /*
 389          * Starts/Stops a counter present on the PMU.
 390          *
 391          * The PMI handler should stop the counter when perf_event_overflow()
 392          * returns !0. ->start() will be used to continue.
 393          *
 394          * Also used to change the sample period.
 395          *
 396          * Called with IRQs disabled and the PMU disabled on the CPU the event
 397          * is on -- will be called from NMI context with the PMU generates
 398          * NMIs.
 399          *
 400          * ->stop() with PERF_EF_UPDATE will read the counter and update
 401          *  period/count values like ->read() would.
 402          *
 403          * ->start() with PERF_EF_RELOAD will reprogram the counter
 404          *  value, must be preceded by a ->stop() with PERF_EF_UPDATE.
 405          */
 406         void (*start)                   (struct perf_event *event, int flags);
 407         void (*stop)                    (struct perf_event *event, int flags);
 408
 409         /*
 410          * Updates the counter value of the event.
 411          *
 412          * For sampling capable PMUs this will also update the software period
 413          * hw_perf_event::period_left field.
 414          */
 415         void (*read)                    (struct perf_event *event);
 416
 417         /*
 418          * Group events scheduling is treated as a transaction, add
 419          * group events as a whole and perform one schedulability test.
 420          * If the test fails, roll back the whole group
 421          *
 422          * Start the transaction, after this ->add() doesn't need to
 423          * do schedulability tests.
 424          *
 425          * Optional.
 426          */
 427         void (*start_txn)               (struct pmu *pmu, unsigned int txn_flags);
 428         /*
 429          * If ->start_txn() disabled the ->add() schedulability test
 430          * then ->commit_txn() is required to perform one. On success
 431          * the transaction is closed. On error the transaction is kept
 432          * open until ->cancel_txn() is called.
 433          *
 434          * Optional.
 435          */
 436         int  (*commit_txn)              (struct pmu *pmu);
 437         /*
 438          * Will cancel the transaction, assumes ->del() is called
 439          * for each successful ->add() during the transaction.
 440          *
 441          * Optional.
 442          */
 443         void (*cancel_txn)              (struct pmu *pmu);
 444
 445         /*
 446          * Will return the value for perf_event_mmap_page::index for this event,
 447          * if no implementation is provided it will default to 0 (see
 448          * perf_event_idx_default).
 449          */
 450         int (*event_idx)                (struct perf_event *event); /*optional */
 451
 452         /*
 453          * context-switches callback
 454          */
 455         void (*sched_task)              (struct perf_event_pmu_context *pmu_ctx,
 456                                         bool sched_in);
 457
 458         /*
 459          * Kmem cache of PMU specific data
 460          */
 461         struct kmem_cache               *task_ctx_cache;
 462
 463         /*
 464          * PMU specific parts of task perf event context (i.e. ctx->task_ctx_data)
 465          * can be synchronized using this function. See Intel LBR callstack support
 466          * implementation and Perf core context switch handling callbacks for usage
 467          * examples.
 468          */
 469         void (*swap_task_ctx)           (struct perf_event_pmu_context *prev_epc,
 470                                          struct perf_event_pmu_context *next_epc);
 471                                         /* optional */
 472
 473         /*
 474          * Set up pmu-private data structures for an AUX area
 475          */
 476         void *(*setup_aux)              (struct perf_event *event, void **pages,
 477                                          int nr_pages, bool overwrite);
 478                                         /* optional */
 479
 480         /*
 481          * Free pmu-private AUX data structures
 482          */
 483         void (*free_aux)                (void *aux); /* optional */
 484
 485         /*
 486          * Take a snapshot of the AUX buffer without touching the event
 487          * state, so that preempting ->start()/->stop() callbacks does
 488          * not interfere with their logic. Called in PMI context.
 489          *
 490          * Returns the size of AUX data copied to the output handle.
 491          *
 492          * Optional.
 493          */
 494         long (*snapshot_aux)            (struct perf_event *event,
 495                                          struct perf_output_handle *handle,
 496                                          unsigned long size);
 497
 498         /*
 499          * Validate address range filters: make sure the HW supports the
 500          * requested configuration and number of filters; return 0 if the
 501          * supplied filters are valid, -errno otherwise.
 502          *
 503          * Runs in the context of the ioctl()ing process and is not serialized
 504          * with the rest of the PMU callbacks.
 505          */
 506         int (*addr_filters_validate)    (struct list_head *filters);
 507                                         /* optional */
 508
 509         /*
 510          * Synchronize address range filter configuration:
 511          * translate hw-agnostic filters into hardware configuration in
 512          * event::hw::addr_filters.
 513          *
 514          * Runs as a part of filter sync sequence that is done in ->start()
 515          * callback by calling perf_event_addr_filters_sync().
 516          *
 517          * May (and should) traverse event::addr_filters::list, for which its
 518          * caller provides necessary serialization.
 519          */
 520         void (*addr_filters_sync)       (struct perf_event *event);
 521                                         /* optional */
 522
 523         /*
 524          * Check if event can be used for aux_output purposes for
 525          * events of this PMU.
 526          *
 527          * Runs from perf_event_open(). Should return 0 for "no match"
 528          * or non-zero for "match".
 529          */
 530         int (*aux_output_match)         (struct perf_event *event);
 531                                         /* optional */
 532
 533         /*
 534          * Skip programming this PMU on the given CPU. Typically needed for
 535          * big.LITTLE things.
 536          */
 537         bool (*filter)                  (struct pmu *pmu, int cpu); /* optional */
 538
 539         /*
 540          * Check period value for PERF_EVENT_IOC_PERIOD ioctl.
 541          */
 542         int (*check_period)             (struct perf_event *event, u64 value); /* optional */
 543 };
 544
 545 enum perf_addr_filter_action_t {
 546         PERF_ADDR_FILTER_ACTION_STOP = 0,
 547         PERF_ADDR_FILTER_ACTION_START,
 548         PERF_ADDR_FILTER_ACTION_FILTER,
 549 };
 550
 551 /**
 552  * struct perf_addr_filter - address range filter definition
 553  * @entry:      event's filter list linkage
 554  * @path:       object file's path for file-based filters
 555  * @offset:     filter range offset
 556  * @size:       filter range size (size==0 means single address trigger)
 557  * @action:     filter/start/stop
 558  *
 559  * This is a hardware-agnostic filter configuration as specified by the user.
 560  */
 561 struct perf_addr_filter {
 562         struct list_head        entry;
 563         struct path             path;
 564         unsigned long           offset;
 565         unsigned long           size;
 566         enum perf_addr_filter_action_t  action;
 567 };
 568
 569 /**
 570  * struct perf_addr_filters_head - container for address range filters
 571  * @list:       list of filters for this event
 572  * @lock:       spinlock that serializes accesses to the @list and event's
 573  *              (and its children's) filter generations.
 574  * @nr_file_filters:    number of file-based filters
 575  *
 576  * A child event will use parent's @list (and therefore @lock), so they are
 577  * bundled together; see perf_event_addr_filters().
 578  */
 579 struct perf_addr_filters_head {
 580         struct list_head        list;
 581         raw_spinlock_t          lock;
 582         unsigned int            nr_file_filters;
 583 };
 584
 585 struct perf_addr_filter_range {
 586         unsigned long           start;
 587         unsigned long           size;
 588 };
 589
 590 /**
 591  * enum perf_event_state - the states of an event:
 592  */
 593 enum perf_event_state {
 594         PERF_EVENT_STATE_DEAD           = -4,
 595         PERF_EVENT_STATE_EXIT           = -3,
 596         PERF_EVENT_STATE_ERROR          = -2,
 597         PERF_EVENT_STATE_OFF            = -1,
 598         PERF_EVENT_STATE_INACTIVE       =  0,
 599         PERF_EVENT_STATE_ACTIVE         =  1,
 600 };
 601
 602 struct file;
 603 struct perf_sample_data;
 604
 605 typedef void (*perf_overflow_handler_t)(struct perf_event *,
 606                                         struct perf_sample_data *,
 607                                         struct pt_regs *regs);
 608
 609 /*
 610  * Event capabilities. For event_caps and groups caps.
 611  *
 612  * PERF_EV_CAP_SOFTWARE: Is a software event.
 613  * PERF_EV_CAP_READ_ACTIVE_PKG: A CPU event (or cgroup event) that can be read
 614  * from any CPU in the package where it is active.
 615  * PERF_EV_CAP_SIBLING: An event with this flag must be a group sibling and
 616  * cannot be a group leader. If an event with this flag is detached from the
 617  * group it is scheduled out and moved into an unrecoverable ERROR state.
 618  */
 619 #define PERF_EV_CAP_SOFTWARE            BIT(0)
 620 #define PERF_EV_CAP_READ_ACTIVE_PKG     BIT(1)
 621 #define PERF_EV_CAP_SIBLING             BIT(2)
 622
 623 #define SWEVENT_HLIST_BITS              8
 624 #define SWEVENT_HLIST_SIZE              (1 << SWEVENT_HLIST_BITS)
 625
 626 struct swevent_hlist {
 627         struct hlist_head               heads[SWEVENT_HLIST_SIZE];
 628         struct rcu_head                 rcu_head;
 629 };
 630
 631 #define PERF_ATTACH_CONTEXT     0x01
 632 #define PERF_ATTACH_GROUP       0x02
 633 #define PERF_ATTACH_TASK        0x04
 634 #define PERF_ATTACH_TASK_DATA   0x08
 635 #define PERF_ATTACH_ITRACE      0x10
 636 #define PERF_ATTACH_SCHED_CB    0x20
 637 #define PERF_ATTACH_CHILD       0x40
 638
 639 struct bpf_prog;
 640 struct perf_cgroup;
 641 struct perf_buffer;
 642
 643 struct pmu_event_list {
 644         raw_spinlock_t          lock;
 645         struct list_head        list;
 646 };
 647
 648 /*
 649  * event->sibling_list is modified whole holding both ctx->lock and ctx->mutex
 650  * as such iteration must hold either lock. However, since ctx->lock is an IRQ
 651  * safe lock, and is only held by the CPU doing the modification, having IRQs
 652  * disabled is sufficient since it will hold-off the IPIs.
 653  */
 654 #ifdef CONFIG_PROVE_LOCKING
 655 #define lockdep_assert_event_ctx(event)                         \
 656         WARN_ON_ONCE(__lockdep_enabled &&                       \
 657                      (this_cpu_read(hardirqs_enabled) &&        \
 658                       lockdep_is_held(&(event)->ctx->mutex) != LOCK_STATE_HELD))
 659 #else
 660 #define lockdep_assert_event_ctx(event)
 661 #endif
 662
 663 #define for_each_sibling_event(sibling, event)                  \
 664         lockdep_assert_event_ctx(event);                        \
 665         if ((event)->group_leader == (event))                   \
 666                 list_for_each_entry((sibling), &(event)->sibling_list, sibling_list)
 667
 668 /**
 669  * struct perf_event - performance event kernel representation:
 670  */
 671 struct perf_event {
 672 #ifdef CONFIG_PERF_EVENTS
 673         /*
 674          * entry onto perf_event_context::event_list;
 675          *   modifications require ctx->lock
 676          *   RCU safe iterations.
 677          */
 678         struct list_head                event_entry;
 679
 680         /*
 681          * Locked for modification by both ctx->mutex and ctx->lock; holding
 682          * either sufficies for read.
 683          */
 684         struct list_head                sibling_list;
 685         struct list_head                active_list;
 686         /*
 687          * Node on the pinned or flexible tree located at the event context;
 688          */
 689         struct rb_node                  group_node;
 690         u64                             group_index;
 691         /*
 692          * We need storage to track the entries in perf_pmu_migrate_context; we
 693          * cannot use the event_entry because of RCU and we want to keep the
 694          * group in tact which avoids us using the other two entries.
 695          */
 696         struct list_head                migrate_entry;
 697
 698         struct hlist_node               hlist_entry;
 699         struct list_head                active_entry;
 700         int                             nr_siblings;
 701
 702         /* Not serialized. Only written during event initialization. */
 703         int                             event_caps;
 704         /* The cumulative AND of all event_caps for events in this group. */
 705         int                             group_caps;
 706
 707         unsigned int                    group_generation;
 708         struct perf_event               *group_leader;
 709         /*
 710          * event->pmu will always point to pmu in which this event belongs.
 711          * Whereas event->pmu_ctx->pmu may point to other pmu when group of
 712          * different pmu events is created.
 713          */
 714         struct pmu                      *pmu;
 715         void                            *pmu_private;
 716
 717         enum perf_event_state           state;
 718         unsigned int                    attach_state;
 719         local64_t                       count;
 720         atomic64_t                      child_count;
 721
 722         /*
 723          * These are the total time in nanoseconds that the event
 724          * has been enabled (i.e. eligible to run, and the task has
 725          * been scheduled in, if this is a per-task event)
 726          * and running (scheduled onto the CPU), respectively.
 727          */
 728         u64                             total_time_enabled;
 729         u64                             total_time_running;
 730         u64                             tstamp;
 731
 732         struct perf_event_attr          attr;
 733         u16                             header_size;
 734         u16                             id_header_size;
 735         u16                             read_size;
 736         struct hw_perf_event            hw;
 737
 738         struct perf_event_context       *ctx;
 739         /*
 740          * event->pmu_ctx points to perf_event_pmu_context in which the event
 741          * is added. This pmu_ctx can be of other pmu for sw event when that
 742          * sw event is part of a group which also contains non-sw events.
 743          */
 744         struct perf_event_pmu_context   *pmu_ctx;
 745         atomic_long_t                   refcount;
 746
 747         /*
 748          * These accumulate total time (in nanoseconds) that children
 749          * events have been enabled and running, respectively.
 750          */
 751         atomic64_t                      child_total_time_enabled;
 752         atomic64_t                      child_total_time_running;
 753
 754         /*
 755          * Protect attach/detach and child_list:
 756          */
 757         struct mutex                    child_mutex;
 758         struct list_head                child_list;
 759         struct perf_event               *parent;
 760
 761         int                             oncpu;
 762         int                             cpu;
 763
 764         struct list_head                owner_entry;
 765         struct task_struct              *owner;
 766
 767         /* mmap bits */
 768         struct mutex                    mmap_mutex;
 769         atomic_t                        mmap_count;
 770
 771         struct perf_buffer              *rb;
 772         struct list_head                rb_entry;
 773         unsigned long                   rcu_batches;
 774         int                             rcu_pending;
 775
 776         /* poll related */
 777         wait_queue_head_t               waitq;
 778         struct fasync_struct            *fasync;
 779
 780         /* delayed work for NMIs and such */
 781         unsigned int                    pending_wakeup;
 782         unsigned int                    pending_kill;
 783         unsigned int                    pending_disable;
 784         unsigned int                    pending_sigtrap;
 785         unsigned long                   pending_addr;   /* SIGTRAP */
 786         struct irq_work                 pending_irq;
 787         struct callback_head            pending_task;
 788         unsigned int                    pending_work;
 789
 790         atomic_t                        event_limit;
 791
 792         /* address range filters */
 793         struct perf_addr_filters_head   addr_filters;
 794         /* vma address array for file-based filders */
 795         struct perf_addr_filter_range   *addr_filter_ranges;
 796         unsigned long                   addr_filters_gen;
 797
 798         /* for aux_output events */
 799         struct perf_event               *aux_event;
 800
 801         void (*destroy)(struct perf_event *);
 802         struct rcu_head                 rcu_head;
 803
 804         struct pid_namespace            *ns;
 805         u64                             id;
 806
 807         atomic64_t                      lost_samples;
 808
 809         u64                             (*clock)(void);
 810         perf_overflow_handler_t         overflow_handler;
 811         void                            *overflow_handler_context;
 812 #ifdef CONFIG_BPF_SYSCALL
 813         perf_overflow_handler_t         orig_overflow_handler;
 814         struct bpf_prog                 *prog;
 815         u64                             bpf_cookie;
 816 #endif
 817
 818 #ifdef CONFIG_EVENT_TRACING
 819         struct trace_event_call         *tp_event;
 820         struct event_filter             *filter;
 821 #ifdef CONFIG_FUNCTION_TRACER
 822         struct ftrace_ops               ftrace_ops;
 823 #endif
 824 #endif
 825
 826 #ifdef CONFIG_CGROUP_PERF
 827         struct perf_cgroup              *cgrp; /* cgroup event is attach to */
 828 #endif
 829
 830 #ifdef CONFIG_SECURITY
 831         void *security;
 832 #endif
 833         struct list_head                sb_list;
 834
 835         /*
 836          * Certain events gets forwarded to another pmu internally by over-
 837          * writing kernel copy of event->attr.type without user being aware
 838          * of it. event->orig_type contains original 'type' requested by
 839          * user.
 840          */
 841         __u32                           orig_type;
 842 #endif /* CONFIG_PERF_EVENTS */
 843 };
 844
 845 /*
 846  *           ,-----------------------[1:n]------------------------.
 847  *           V                                                    V
 848  * perf_event_context <-[1:n]-> perf_event_pmu_context <-[1:n]- perf_event
 849  *                                        |                       |
 850  *                                        `--[n:1]-> pmu <-[1:n]--'
 851  *
 852  *
 853  * struct perf_event_pmu_context  lifetime is refcount based and RCU freed
 854  * (similar to perf_event_context). Locking is as if it were a member of
 855  * perf_event_context; specifically:
 856  *
 857  *   modification, both: ctx->mutex && ctx->lock
 858  *   reading, either:    ctx->mutex || ctx->lock
 859  *
 860  * There is one exception to this; namely put_pmu_ctx() isn't always called
 861  * with ctx->mutex held; this means that as long as we can guarantee the epc
 862  * has events the above rules hold.
 863  *
 864  * Specificially, sys_perf_event_open()'s group_leader case depends on
 865  * ctx->mutex pinning the configuration. Since we hold a reference on
 866  * group_leader (through the filedesc) it can't go away, therefore it's
 867  * associated pmu_ctx must exist and cannot change due to ctx->mutex.
 868  *
 869  * perf_event holds a refcount on perf_event_context
 870  * perf_event holds a refcount on perf_event_pmu_context
 871  */
 872 struct perf_event_pmu_context {
 873         struct pmu                      *pmu;
 874         struct perf_event_context       *ctx;
 875
 876         struct list_head                pmu_ctx_entry;
 877
 878         struct list_head                pinned_active;
 879         struct list_head                flexible_active;
 880
 881         /* Used to avoid freeing per-cpu perf_event_pmu_context */
 882         unsigned int                    embedded : 1;
 883
 884         unsigned int                    nr_events;
 885         unsigned int                    nr_cgroups;
 886
 887         atomic_t                        refcount; /* event <-> epc */
 888         struct rcu_head                 rcu_head;
 889
 890         void                            *task_ctx_data; /* pmu specific data */
 891         /*
 892          * Set when one or more (plausibly active) event can't be scheduled
 893          * due to pmu overcommit or pmu constraints, except tolerant to
 894          * events not necessary to be active due to scheduling constraints,
 895          * such as cgroups.
 896          */
 897         int                             rotate_necessary;
 898 };
 899
 900 struct perf_event_groups {
 901         struct rb_root  tree;
 902         u64             index;
 903 };
 904
 905
 906 /**
 907  * struct perf_event_context - event context structure
 908  *
 909  * Used as a container for task events and CPU events as well:
 910  */
 911 struct perf_event_context {
 912         /*
 913          * Protect the states of the events in the list,
 914          * nr_active, and the list:
 915          */
 916         raw_spinlock_t                  lock;
 917         /*
 918          * Protect the list of events.  Locking either mutex or lock
 919          * is sufficient to ensure the list doesn't change; to change
 920          * the list you need to lock both the mutex and the spinlock.
 921          */
 922         struct mutex                    mutex;
 923
 924         struct list_head                pmu_ctx_list;
 925         struct perf_event_groups        pinned_groups;
 926         struct perf_event_groups        flexible_groups;
 927         struct list_head                event_list;
 928
 929         int                             nr_events;
 930         int                             nr_user;
 931         int                             is_active;
 932
 933         int                             nr_task_data;
 934         int                             nr_stat;
 935         int                             nr_freq;
 936         int                             rotate_disable;
 937
 938         refcount_t                      refcount; /* event <-> ctx */
 939         struct task_struct              *task;
 940
 941         /*
 942          * Context clock, runs when context enabled.
 943          */
 944         u64                             time;
 945         u64                             timestamp;
 946         u64                             timeoffset;
 947
 948         /*
 949          * These fields let us detect when two contexts have both
 950          * been cloned (inherited) from a common ancestor.
 951          */
 952         struct perf_event_context       *parent_ctx;
 953         u64                             parent_gen;
 954         u64                             generation;
 955         int                             pin_count;
 956 #ifdef CONFIG_CGROUP_PERF
 957         int                             nr_cgroups;      /* cgroup evts */
 958 #endif
 959         struct rcu_head                 rcu_head;
 960
 961         /*
 962          * Sum (event->pending_sigtrap + event->pending_work)
 963          *
 964          * The SIGTRAP is targeted at ctx->task, as such it won't do changing
 965          * that until the signal is delivered.
 966          */
 967         local_t                         nr_pending;
 968 };
 969
 970 /*
 971  * Number of contexts where an event can trigger:
 972  *      task, softirq, hardirq, nmi.
 973  */
 974 #define PERF_NR_CONTEXTS        4
 975
 976 struct perf_cpu_pmu_context {
 977         struct perf_event_pmu_context   epc;
 978         struct perf_event_pmu_context   *task_epc;
 979
 980         struct list_head                sched_cb_entry;
 981         int                             sched_cb_usage;
 982
 983         int                             active_oncpu;
 984         int                             exclusive;
 985
 986         raw_spinlock_t                  hrtimer_lock;
 987         struct hrtimer                  hrtimer;
 988         ktime_t                         hrtimer_interval;
 989         unsigned int                    hrtimer_active;
 990 };
 991
 992 /**
 993  * struct perf_event_cpu_context - per cpu event context structure
 994  */
 995 struct perf_cpu_context {
 996         struct perf_event_context       ctx;
 997         struct perf_event_context       *task_ctx;
 998         int                             online;
 999
1000 #ifdef CONFIG_CGROUP_PERF
1001         struct perf_cgroup              *cgrp;
1002 #endif
1003
1004         /*
1005          * Per-CPU storage for iterators used in visit_groups_merge. The default
1006          * storage is of size 2 to hold the CPU and any CPU event iterators.
1007          */
1008         int                             heap_size;
1009         struct perf_event               **heap;
1010         struct perf_event               *heap_default[2];
1011 };
1012
1013 struct perf_output_handle {
1014         struct perf_event               *event;
1015         struct perf_buffer              *rb;
1016         unsigned long                   wakeup;
1017         unsigned long                   size;
1018         u64                             aux_flags;
1019         union {
1020                 void                    *addr;
1021                 unsigned long           head;
1022         };
1023         int                             page;
1024 };
1025
1026 struct bpf_perf_event_data_kern {
1027         bpf_user_pt_regs_t *regs;
1028         struct perf_sample_data *data;
1029         struct perf_event *event;
1030 };
1031
1032 #ifdef CONFIG_CGROUP_PERF
1033
1034 /*
1035  * perf_cgroup_info keeps track of time_enabled for a cgroup.
1036  * This is a per-cpu dynamically allocated data structure.
1037  */
1038 struct perf_cgroup_info {
1039         u64                             time;
1040         u64                             timestamp;
1041         u64                             timeoffset;
1042         int                             active;
1043 };
1044
1045 struct perf_cgroup {
1046         struct cgroup_subsys_state      css;
1047         struct perf_cgroup_info __percpu *info;
1048 };
1049
1050 /*
1051  * Must ensure cgroup is pinned (css_get) before calling
1052  * this function. In other words, we cannot call this function
1053  * if there is no cgroup event for the current CPU context.
1054  */
1055 static inline struct perf_cgroup *
1056 perf_cgroup_from_task(struct task_struct *task, struct perf_event_context *ctx)
1057 {
1058         return container_of(task_css_check(task, perf_event_cgrp_id,
1059                                            ctx ? lockdep_is_held(&ctx->lock)
1060                                                : true),
1061                             struct perf_cgroup, css);
1062 }
1063 #endif /* CONFIG_CGROUP_PERF */
1064
1065 #ifdef CONFIG_PERF_EVENTS
1066
1067 extern struct perf_event_context *perf_cpu_task_ctx(void);
1068
1069 extern void *perf_aux_output_begin(struct perf_output_handle *handle,
1070                                    struct perf_event *event);
1071 extern void perf_aux_output_end(struct perf_output_handle *handle,
1072                                 unsigned long size);
1073 extern int perf_aux_output_skip(struct perf_output_handle *handle,
1074                                 unsigned long size);
1075 extern void *perf_get_aux(struct perf_output_handle *handle);
1076 extern void perf_aux_output_flag(struct perf_output_handle *handle, u64 flags);
1077 extern void perf_event_itrace_started(struct perf_event *event);
1078
1079 extern int perf_pmu_register(struct pmu *pmu, const char *name, int type);
1080 extern void perf_pmu_unregister(struct pmu *pmu);
1081
1082 extern void __perf_event_task_sched_in(struct task_struct *prev,
1083                                        struct task_struct *task);
1084 extern void __perf_event_task_sched_out(struct task_struct *prev,
1085                                         struct task_struct *next);
1086 extern int perf_event_init_task(struct task_struct *child, u64 clone_flags);
1087 extern void perf_event_exit_task(struct task_struct *child);
1088 extern void perf_event_free_task(struct task_struct *task);
1089 extern void perf_event_delayed_put(struct task_struct *task);
1090 extern struct file *perf_event_get(unsigned int fd);
1091 extern const struct perf_event *perf_get_event(struct file *file);
1092 extern const struct perf_event_attr *perf_event_attrs(struct perf_event *event);
1093 extern void perf_event_print_debug(void);
1094 extern void perf_pmu_disable(struct pmu *pmu);
1095 extern void perf_pmu_enable(struct pmu *pmu);
1096 extern void perf_sched_cb_dec(struct pmu *pmu);
1097 extern void perf_sched_cb_inc(struct pmu *pmu);
1098 extern int perf_event_task_disable(void);
1099 extern int perf_event_task_enable(void);
1100
1101 extern void perf_pmu_resched(struct pmu *pmu);
1102
1103 extern int perf_event_refresh(struct perf_event *event, int refresh);
1104 extern void perf_event_update_userpage(struct perf_event *event);
1105 extern int perf_event_release_kernel(struct perf_event *event);
1106 extern struct perf_event *
1107 perf_event_create_kernel_counter(struct perf_event_attr *attr,
1108                                 int cpu,
1109                                 struct task_struct *task,
1110                                 perf_overflow_handler_t callback,
1111                                 void *context);
1112 extern void perf_pmu_migrate_context(struct pmu *pmu,
1113                                 int src_cpu, int dst_cpu);
1114 int perf_event_read_local(struct perf_event *event, u64 *value,
1115                           u64 *enabled, u64 *running);
1116 extern u64 perf_event_read_value(struct perf_event *event,
1117                                  u64 *enabled, u64 *running);
1118
1119 extern struct perf_callchain_entry *perf_callchain(struct perf_event *event, struct pt_regs *regs);
1120
1121 static inline bool branch_sample_no_flags(const struct perf_event *event)
1122 {
1123         return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_NO_FLAGS;
1124 }
1125
1126 static inline bool branch_sample_no_cycles(const struct perf_event *event)
1127 {
1128         return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_NO_CYCLES;
1129 }
1130
1131 static inline bool branch_sample_type(const struct perf_event *event)
1132 {
1133         return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_TYPE_SAVE;
1134 }
1135
1136 static inline bool branch_sample_hw_index(const struct perf_event *event)
1137 {
1138         return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_HW_INDEX;
1139 }
1140
1141 static inline bool branch_sample_priv(const struct perf_event *event)
1142 {
1143         return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_PRIV_SAVE;
1144 }
1145
1146 static inline bool branch_sample_counters(const struct perf_event *event)
1147 {
1148         return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_COUNTERS;
1149 }
1150
1151 static inline bool branch_sample_call_stack(const struct perf_event *event)
1152 {
1153         return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK;
1154 }
1155
1156 struct perf_sample_data {
1157         /*
1158          * Fields set by perf_sample_data_init() unconditionally,
1159          * group so as to minimize the cachelines touched.
1160          */
1161         u64                             sample_flags;
1162         u64                             period;
1163         u64                             dyn_size;
1164
1165         /*
1166          * Fields commonly set by __perf_event_header__init_id(),
1167          * group so as to minimize the cachelines touched.
1168          */
1169         u64                             type;
1170         struct {
1171                 u32     pid;
1172                 u32     tid;
1173         }                               tid_entry;
1174         u64                             time;
1175         u64                             id;
1176         struct {
1177                 u32     cpu;
1178                 u32     reserved;
1179         }                               cpu_entry;
1180
1181         /*
1182          * The other fields, optionally {set,used} by
1183          * perf_{prepare,output}_sample().
1184          */
1185         u64                             ip;
1186         struct perf_callchain_entry     *callchain;
1187         struct perf_raw_record          *raw;
1188         struct perf_branch_stack        *br_stack;
1189         u64                             *br_stack_cntr;
1190         union perf_sample_weight        weight;
1191         union  perf_mem_data_src        data_src;
1192         u64                             txn;
1193
1194         struct perf_regs                regs_user;
1195         struct perf_regs                regs_intr;
1196         u64                             stack_user_size;
1197
1198         u64                             stream_id;
1199         u64                             cgroup;
1200         u64                             addr;
1201         u64                             phys_addr;
1202         u64                             data_page_size;
1203         u64                             code_page_size;
1204         u64                             aux_size;
1205 } ____cacheline_aligned;
1206
1207 /* default value for data source */
1208 #define PERF_MEM_NA (PERF_MEM_S(OP, NA)   |\
1209                     PERF_MEM_S(LVL, NA)   |\
1210                     PERF_MEM_S(SNOOP, NA) |\
1211                     PERF_MEM_S(LOCK, NA)  |\
1212                     PERF_MEM_S(TLB, NA)   |\
1213                     PERF_MEM_S(LVLNUM, NA))
1214
1215 static inline void perf_sample_data_init(struct perf_sample_data *data,
1216                                          u64 addr, u64 period)
1217 {
1218         /* remaining struct members initialized in perf_prepare_sample() */
1219         data->sample_flags = PERF_SAMPLE_PERIOD;
1220         data->period = period;
1221         data->dyn_size = 0;
1222
1223         if (addr) {
1224                 data->addr = addr;
1225                 data->sample_flags |= PERF_SAMPLE_ADDR;
1226         }
1227 }
1228
1229 static inline void perf_sample_save_callchain(struct perf_sample_data *data,
1230                                               struct perf_event *event,
1231                                               struct pt_regs *regs)
1232 {
1233         int size = 1;
1234
1235         data->callchain = perf_callchain(event, regs);
1236         size += data->callchain->nr;
1237
1238         data->dyn_size += size * sizeof(u64);
1239         data->sample_flags |= PERF_SAMPLE_CALLCHAIN;
1240 }
1241
1242 static inline void perf_sample_save_raw_data(struct perf_sample_data *data,
1243                                              struct perf_raw_record *raw)
1244 {
1245         struct perf_raw_frag *frag = &raw->frag;
1246         u32 sum = 0;
1247         int size;
1248
1249         do {
1250                 sum += frag->size;
1251                 if (perf_raw_frag_last(frag))
1252                         break;
1253                 frag = frag->next;
1254         } while (1);
1255
1256         size = round_up(sum + sizeof(u32), sizeof(u64));
1257         raw->size = size - sizeof(u32);
1258         frag->pad = raw->size - sum;
1259
1260         data->raw = raw;
1261         data->dyn_size += size;
1262         data->sample_flags |= PERF_SAMPLE_RAW;
1263 }
1264
1265 static inline void perf_sample_save_brstack(struct perf_sample_data *data,
1266                                             struct perf_event *event,
1267                                             struct perf_branch_stack *brs,
1268                                             u64 *brs_cntr)
1269 {
1270         int size = sizeof(u64); /* nr */
1271
1272         if (branch_sample_hw_index(event))
1273                 size += sizeof(u64);
1274         size += brs->nr * sizeof(struct perf_branch_entry);
1275
1276         /*
1277          * The extension space for counters is appended after the
1278          * struct perf_branch_stack. It is used to store the occurrences
1279          * of events of each branch.
1280          */
1281         if (brs_cntr)
1282                 size += brs->nr * sizeof(u64);
1283
1284         data->br_stack = brs;
1285         data->br_stack_cntr = brs_cntr;
1286         data->dyn_size += size;
1287         data->sample_flags |= PERF_SAMPLE_BRANCH_STACK;
1288 }
1289
1290 static inline u32 perf_sample_data_size(struct perf_sample_data *data,
1291                                         struct perf_event *event)
1292 {
1293         u32 size = sizeof(struct perf_event_header);
1294
1295         size += event->header_size + event->id_header_size;
1296         size += data->dyn_size;
1297
1298         return size;
1299 }
1300
1301 /*
1302  * Clear all bitfields in the perf_branch_entry.
1303  * The to and from fields are not cleared because they are
1304  * systematically modified by caller.
1305  */
1306 static inline void perf_clear_branch_entry_bitfields(struct perf_branch_entry *br)
1307 {
1308         br->mispred = 0;
1309         br->predicted = 0;
1310         br->in_tx = 0;
1311         br->abort = 0;
1312         br->cycles = 0;
1313         br->type = 0;
1314         br->spec = PERF_BR_SPEC_NA;
1315         br->reserved = 0;
1316 }
1317
1318 extern void perf_output_sample(struct perf_output_handle *handle,
1319                                struct perf_event_header *header,
1320                                struct perf_sample_data *data,
1321                                struct perf_event *event);
1322 extern void perf_prepare_sample(struct perf_sample_data *data,
1323                                 struct perf_event *event,
1324                                 struct pt_regs *regs);
1325 extern void perf_prepare_header(struct perf_event_header *header,
1326                                 struct perf_sample_data *data,
1327                                 struct perf_event *event,
1328                                 struct pt_regs *regs);
1329
1330 extern int perf_event_overflow(struct perf_event *event,
1331                                  struct perf_sample_data *data,
1332                                  struct pt_regs *regs);
1333
1334 extern void perf_event_output_forward(struct perf_event *event,
1335                                      struct perf_sample_data *data,
1336                                      struct pt_regs *regs);
1337 extern void perf_event_output_backward(struct perf_event *event,
1338                                        struct perf_sample_data *data,
1339                                        struct pt_regs *regs);
1340 extern int perf_event_output(struct perf_event *event,
1341                              struct perf_sample_data *data,
1342                              struct pt_regs *regs);
1343
1344 static inline bool
1345 __is_default_overflow_handler(perf_overflow_handler_t overflow_handler)
1346 {
1347         if (likely(overflow_handler == perf_event_output_forward))
1348                 return true;
1349         if (unlikely(overflow_handler == perf_event_output_backward))
1350                 return true;
1351         return false;
1352 }
1353
1354 #define is_default_overflow_handler(event) \
1355         __is_default_overflow_handler((event)->overflow_handler)
1356
1357 #ifdef CONFIG_BPF_SYSCALL
1358 static inline bool uses_default_overflow_handler(struct perf_event *event)
1359 {
1360         if (likely(is_default_overflow_handler(event)))
1361                 return true;
1362
1363         return __is_default_overflow_handler(event->orig_overflow_handler);
1364 }
1365 #else
1366 #define uses_default_overflow_handler(event) \
1367         is_default_overflow_handler(event)
1368 #endif
1369
1370 extern void
1371 perf_event_header__init_id(struct perf_event_header *header,
1372                            struct perf_sample_data *data,
1373                            struct perf_event *event);
1374 extern void
1375 perf_event__output_id_sample(struct perf_event *event,
1376                              struct perf_output_handle *handle,
1377                              struct perf_sample_data *sample);
1378
1379 extern void
1380 perf_log_lost_samples(struct perf_event *event, u64 lost);
1381
1382 static inline bool event_has_any_exclude_flag(struct perf_event *event)
1383 {
1384         struct perf_event_attr *attr = &event->attr;
1385
1386         return attr->exclude_idle || attr->exclude_user ||
1387                attr->exclude_kernel || attr->exclude_hv ||
1388                attr->exclude_guest || attr->exclude_host;
1389 }
1390
1391 static inline bool is_sampling_event(struct perf_event *event)
1392 {
1393         return event->attr.sample_period != 0;
1394 }
1395
1396 /*
1397  * Return 1 for a software event, 0 for a hardware event
1398  */
1399 static inline int is_software_event(struct perf_event *event)
1400 {
1401         return event->event_caps & PERF_EV_CAP_SOFTWARE;
1402 }
1403
1404 /*
1405  * Return 1 for event in sw context, 0 for event in hw context
1406  */
1407 static inline int in_software_context(struct perf_event *event)
1408 {
1409         return event->pmu_ctx->pmu->task_ctx_nr == perf_sw_context;
1410 }
1411
1412 static inline int is_exclusive_pmu(struct pmu *pmu)
1413 {
1414         return pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE;
1415 }
1416
1417 extern struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
1418
1419 extern void ___perf_sw_event(u32, u64, struct pt_regs *, u64);
1420 extern void __perf_sw_event(u32, u64, struct pt_regs *, u64);
1421
1422 #ifndef perf_arch_fetch_caller_regs
1423 static inline void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip) { }
1424 #endif
1425
1426 /*
1427  * When generating a perf sample in-line, instead of from an interrupt /
1428  * exception, we lack a pt_regs. This is typically used from software events
1429  * like: SW_CONTEXT_SWITCHES, SW_MIGRATIONS and the tie-in with tracepoints.
1430  *
1431  * We typically don't need a full set, but (for x86) do require:
1432  * - ip for PERF_SAMPLE_IP
1433  * - cs for user_mode() tests
1434  * - sp for PERF_SAMPLE_CALLCHAIN
1435  * - eflags for MISC bits and CALLCHAIN (see: perf_hw_regs())
1436  *
1437  * NOTE: assumes @regs is otherwise already 0 filled; this is important for
1438  * things like PERF_SAMPLE_REGS_INTR.
1439  */
1440 static inline void perf_fetch_caller_regs(struct pt_regs *regs)
1441 {
1442         perf_arch_fetch_caller_regs(regs, CALLER_ADDR0);
1443 }
1444
1445 static __always_inline void
1446 perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
1447 {
1448         if (static_key_false(&perf_swevent_enabled[event_id]))
1449                 __perf_sw_event(event_id, nr, regs, addr);
1450 }
1451
1452 DECLARE_PER_CPU(struct pt_regs, __perf_regs[4]);
1453
1454 /*
1455  * 'Special' version for the scheduler, it hard assumes no recursion,
1456  * which is guaranteed by us not actually scheduling inside other swevents
1457  * because those disable preemption.
1458  */
1459 static __always_inline void __perf_sw_event_sched(u32 event_id, u64 nr, u64 addr)
1460 {
1461         struct pt_regs *regs = this_cpu_ptr(&__perf_regs[0]);
1462
1463         perf_fetch_caller_regs(regs);
1464         ___perf_sw_event(event_id, nr, regs, addr);
1465 }
1466
1467 extern struct static_key_false perf_sched_events;
1468
1469 static __always_inline bool __perf_sw_enabled(int swevt)
1470 {
1471         return static_key_false(&perf_swevent_enabled[swevt]);
1472 }
1473
1474 static inline void perf_event_task_migrate(struct task_struct *task)
1475 {
1476         if (__perf_sw_enabled(PERF_COUNT_SW_CPU_MIGRATIONS))
1477                 task->sched_migrated = 1;
1478 }
1479
1480 static inline void perf_event_task_sched_in(struct task_struct *prev,
1481                                             struct task_struct *task)
1482 {
1483         if (static_branch_unlikely(&perf_sched_events))
1484                 __perf_event_task_sched_in(prev, task);
1485
1486         if (__perf_sw_enabled(PERF_COUNT_SW_CPU_MIGRATIONS) &&
1487             task->sched_migrated) {
1488                 __perf_sw_event_sched(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 0);
1489                 task->sched_migrated = 0;
1490         }
1491 }
1492
1493 static inline void perf_event_task_sched_out(struct task_struct *prev,
1494                                              struct task_struct *next)
1495 {
1496         if (__perf_sw_enabled(PERF_COUNT_SW_CONTEXT_SWITCHES))
1497                 __perf_sw_event_sched(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 0);
1498
1499 #ifdef CONFIG_CGROUP_PERF
1500         if (__perf_sw_enabled(PERF_COUNT_SW_CGROUP_SWITCHES) &&
1501             perf_cgroup_from_task(prev, NULL) !=
1502             perf_cgroup_from_task(next, NULL))
1503                 __perf_sw_event_sched(PERF_COUNT_SW_CGROUP_SWITCHES, 1, 0);
1504 #endif
1505
1506         if (static_branch_unlikely(&perf_sched_events))
1507                 __perf_event_task_sched_out(prev, next);
1508 }
1509
1510 extern void perf_event_mmap(struct vm_area_struct *vma);
1511
1512 extern void perf_event_ksymbol(u16 ksym_type, u64 addr, u32 len,
1513                                bool unregister, const char *sym);
1514 extern void perf_event_bpf_event(struct bpf_prog *prog,
1515                                  enum perf_bpf_event_type type,
1516                                  u16 flags);
1517
1518 #ifdef CONFIG_GUEST_PERF_EVENTS
1519 extern struct perf_guest_info_callbacks __rcu *perf_guest_cbs;
1520
1521 DECLARE_STATIC_CALL(__perf_guest_state, *perf_guest_cbs->state);
1522 DECLARE_STATIC_CALL(__perf_guest_get_ip, *perf_guest_cbs->get_ip);
1523 DECLARE_STATIC_CALL(__perf_guest_handle_intel_pt_intr, *perf_guest_cbs->handle_intel_pt_intr);
1524
1525 static inline unsigned int perf_guest_state(void)
1526 {
1527         return static_call(__perf_guest_state)();
1528 }
1529 static inline unsigned long perf_guest_get_ip(void)
1530 {
1531         return static_call(__perf_guest_get_ip)();
1532 }
1533 static inline unsigned int perf_guest_handle_intel_pt_intr(void)
1534 {
1535         return static_call(__perf_guest_handle_intel_pt_intr)();
1536 }
1537 extern void perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs);
1538 extern void perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs);
1539 #else
1540 static inline unsigned int perf_guest_state(void)                { return 0; }
1541 static inline unsigned long perf_guest_get_ip(void)              { return 0; }
1542 static inline unsigned int perf_guest_handle_intel_pt_intr(void) { return 0; }
1543 #endif /* CONFIG_GUEST_PERF_EVENTS */
1544
1545 extern void perf_event_exec(void);
1546 extern void perf_event_comm(struct task_struct *tsk, bool exec);
1547 extern void perf_event_namespaces(struct task_struct *tsk);
1548 extern void perf_event_fork(struct task_struct *tsk);
1549 extern void perf_event_text_poke(const void *addr,
1550                                  const void *old_bytes, size_t old_len,
1551                                  const void *new_bytes, size_t new_len);
1552
1553 /* Callchains */
1554 DECLARE_PER_CPU(struct perf_callchain_entry, perf_callchain_entry);
1555
1556 extern void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs);
1557 extern void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs);
1558 extern struct perf_callchain_entry *
1559 get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
1560                    u32 max_stack, bool crosstask, bool add_mark);
1561 extern int get_callchain_buffers(int max_stack);
1562 extern void put_callchain_buffers(void);
1563 extern struct perf_callchain_entry *get_callchain_entry(int *rctx);
1564 extern void put_callchain_entry(int rctx);
1565
1566 extern int sysctl_perf_event_max_stack;
1567 extern int sysctl_perf_event_max_contexts_per_stack;
1568
1569 static inline int perf_callchain_store_context(struct perf_callchain_entry_ctx *ctx, u64 ip)
1570 {
1571         if (ctx->contexts < sysctl_perf_event_max_contexts_per_stack) {
1572                 struct perf_callchain_entry *entry = ctx->entry;
1573                 entry->ip[entry->nr++] = ip;
1574                 ++ctx->contexts;
1575                 return 0;
1576         } else {
1577                 ctx->contexts_maxed = true;
1578                 return -1; /* no more room, stop walking the stack */
1579         }
1580 }
1581
1582 static inline int perf_callchain_store(struct perf_callchain_entry_ctx *ctx, u64 ip)
1583 {
1584         if (ctx->nr < ctx->max_stack && !ctx->contexts_maxed) {
1585                 struct perf_callchain_entry *entry = ctx->entry;
1586                 entry->ip[entry->nr++] = ip;
1587                 ++ctx->nr;
1588                 return 0;
1589         } else {
1590                 return -1; /* no more room, stop walking the stack */
1591         }
1592 }
1593
1594 extern int sysctl_perf_event_paranoid;
1595 extern int sysctl_perf_event_mlock;
1596 extern int sysctl_perf_event_sample_rate;
1597 extern int sysctl_perf_cpu_time_max_percent;
1598
1599 extern void perf_sample_event_took(u64 sample_len_ns);
1600
1601 int perf_event_max_sample_rate_handler(struct ctl_table *table, int write,
1602                 void *buffer, size_t *lenp, loff_t *ppos);
1603 int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
1604                 void *buffer, size_t *lenp, loff_t *ppos);
1605 int perf_event_max_stack_handler(struct ctl_table *table, int write,
1606                 void *buffer, size_t *lenp, loff_t *ppos);
1607
1608 /* Access to perf_event_open(2) syscall. */
1609 #define PERF_SECURITY_OPEN              0
1610
1611 /* Finer grained perf_event_open(2) access control. */
1612 #define PERF_SECURITY_CPU               1
1613 #define PERF_SECURITY_KERNEL            2
1614 #define PERF_SECURITY_TRACEPOINT        3
1615
1616 static inline int perf_is_paranoid(void)
1617 {
1618         return sysctl_perf_event_paranoid > -1;
1619 }
1620
1621 static inline int perf_allow_kernel(struct perf_event_attr *attr)
1622 {
1623         if (sysctl_perf_event_paranoid > 1 && !perfmon_capable())
1624                 return -EACCES;
1625
1626         return security_perf_event_open(attr, PERF_SECURITY_KERNEL);
1627 }
1628
1629 static inline int perf_allow_cpu(struct perf_event_attr *attr)
1630 {
1631         if (sysctl_perf_event_paranoid > 0 && !perfmon_capable())
1632                 return -EACCES;
1633
1634         return security_perf_event_open(attr, PERF_SECURITY_CPU);
1635 }
1636
1637 static inline int perf_allow_tracepoint(struct perf_event_attr *attr)
1638 {
1639         if (sysctl_perf_event_paranoid > -1 && !perfmon_capable())
1640                 return -EPERM;
1641
1642         return security_perf_event_open(attr, PERF_SECURITY_TRACEPOINT);
1643 }
1644
1645 extern void perf_event_init(void);
1646 extern void perf_tp_event(u16 event_type, u64 count, void *record,
1647                           int entry_size, struct pt_regs *regs,
1648                           struct hlist_head *head, int rctx,
1649                           struct task_struct *task);
1650 extern void perf_bp_event(struct perf_event *event, void *data);
1651
1652 #ifndef perf_misc_flags
1653 # define perf_misc_flags(regs) \
1654                 (user_mode(regs) ? PERF_RECORD_MISC_USER : PERF_RECORD_MISC_KERNEL)
1655 # define perf_instruction_pointer(regs) instruction_pointer(regs)
1656 #endif
1657 #ifndef perf_arch_bpf_user_pt_regs
1658 # define perf_arch_bpf_user_pt_regs(regs) regs
1659 #endif
1660
1661 static inline bool has_branch_stack(struct perf_event *event)
1662 {
1663         return event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK;
1664 }
1665
1666 static inline bool needs_branch_stack(struct perf_event *event)
1667 {
1668         return event->attr.branch_sample_type != 0;
1669 }
1670
1671 static inline bool has_aux(struct perf_event *event)
1672 {
1673         return event->pmu->setup_aux;
1674 }
1675
1676 static inline bool is_write_backward(struct perf_event *event)
1677 {
1678         return !!event->attr.write_backward;
1679 }
1680
1681 static inline bool has_addr_filter(struct perf_event *event)
1682 {
1683         return event->pmu->nr_addr_filters;
1684 }
1685
1686 /*
1687  * An inherited event uses parent's filters
1688  */
1689 static inline struct perf_addr_filters_head *
1690 perf_event_addr_filters(struct perf_event *event)
1691 {
1692         struct perf_addr_filters_head *ifh = &event->addr_filters;
1693
1694         if (event->parent)
1695                 ifh = &event->parent->addr_filters;
1696
1697         return ifh;
1698 }
1699
1700 extern void perf_event_addr_filters_sync(struct perf_event *event);
1701 extern void perf_report_aux_output_id(struct perf_event *event, u64 hw_id);
1702
1703 extern int perf_output_begin(struct perf_output_handle *handle,
1704                              struct perf_sample_data *data,
1705                              struct perf_event *event, unsigned int size);
1706 extern int perf_output_begin_forward(struct perf_output_handle *handle,
1707                                      struct perf_sample_data *data,
1708                                      struct perf_event *event,
1709                                      unsigned int size);
1710 extern int perf_output_begin_backward(struct perf_output_handle *handle,
1711                                       struct perf_sample_data *data,
1712                                       struct perf_event *event,
1713                                       unsigned int size);
1714
1715 extern void perf_output_end(struct perf_output_handle *handle);
1716 extern unsigned int perf_output_copy(struct perf_output_handle *handle,
1717                              const void *buf, unsigned int len);
1718 extern unsigned int perf_output_skip(struct perf_output_handle *handle,
1719                                      unsigned int len);
1720 extern long perf_output_copy_aux(struct perf_output_handle *aux_handle,
1721                                  struct perf_output_handle *handle,
1722                                  unsigned long from, unsigned long to);
1723 extern int perf_swevent_get_recursion_context(void);
1724 extern void perf_swevent_put_recursion_context(int rctx);
1725 extern u64 perf_swevent_set_period(struct perf_event *event);
1726 extern void perf_event_enable(struct perf_event *event);
1727 extern void perf_event_disable(struct perf_event *event);
1728 extern void perf_event_disable_local(struct perf_event *event);
1729 extern void perf_event_disable_inatomic(struct perf_event *event);
1730 extern void perf_event_task_tick(void);
1731 extern int perf_event_account_interrupt(struct perf_event *event);
1732 extern int perf_event_period(struct perf_event *event, u64 value);
1733 extern u64 perf_event_pause(struct perf_event *event, bool reset);
1734 #else /* !CONFIG_PERF_EVENTS: */
1735 static inline void *
1736 perf_aux_output_begin(struct perf_output_handle *handle,
1737                       struct perf_event *event)                         { return NULL; }
1738 static inline void
1739 perf_aux_output_end(struct perf_output_handle *handle, unsigned long size)
1740                                                                         { }
1741 static inline int
1742 perf_aux_output_skip(struct perf_output_handle *handle,
1743                      unsigned long size)                                { return -EINVAL; }
1744 static inline void *
1745 perf_get_aux(struct perf_output_handle *handle)                         { return NULL; }
1746 static inline void
1747 perf_event_task_migrate(struct task_struct *task)                       { }
1748 static inline void
1749 perf_event_task_sched_in(struct task_struct *prev,
1750                          struct task_struct *task)                      { }
1751 static inline void
1752 perf_event_task_sched_out(struct task_struct *prev,
1753                           struct task_struct *next)                     { }
1754 static inline int perf_event_init_task(struct task_struct *child,
1755                                        u64 clone_flags)                 { return 0; }
1756 static inline void perf_event_exit_task(struct task_struct *child)      { }
1757 static inline void perf_event_free_task(struct task_struct *task)       { }
1758 static inline void perf_event_delayed_put(struct task_struct *task)     { }
1759 static inline struct file *perf_event_get(unsigned int fd)      { return ERR_PTR(-EINVAL); }
1760 static inline const struct perf_event *perf_get_event(struct file *file)
1761 {
1762         return ERR_PTR(-EINVAL);
1763 }
1764 static inline const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
1765 {
1766         return ERR_PTR(-EINVAL);
1767 }
1768 static inline int perf_event_read_local(struct perf_event *event, u64 *value,
1769                                         u64 *enabled, u64 *running)
1770 {
1771         return -EINVAL;
1772 }
1773 static inline void perf_event_print_debug(void)                         { }
1774 static inline int perf_event_task_disable(void)                         { return -EINVAL; }
1775 static inline int perf_event_task_enable(void)                          { return -EINVAL; }
1776 static inline int perf_event_refresh(struct perf_event *event, int refresh)
1777 {
1778         return -EINVAL;
1779 }
1780
1781 static inline void
1782 perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)     { }
1783 static inline void
1784 perf_bp_event(struct perf_event *event, void *data)                     { }
1785
1786 static inline void perf_event_mmap(struct vm_area_struct *vma)          { }
1787
1788 typedef int (perf_ksymbol_get_name_f)(char *name, int name_len, void *data);
1789 static inline void perf_event_ksymbol(u16 ksym_type, u64 addr, u32 len,
1790                                       bool unregister, const char *sym) { }
1791 static inline void perf_event_bpf_event(struct bpf_prog *prog,
1792                                         enum perf_bpf_event_type type,
1793                                         u16 flags)                      { }
1794 static inline void perf_event_exec(void)                                { }
1795 static inline void perf_event_comm(struct task_struct *tsk, bool exec)  { }
1796 static inline void perf_event_namespaces(struct task_struct *tsk)       { }
1797 static inline void perf_event_fork(struct task_struct *tsk)             { }
1798 static inline void perf_event_text_poke(const void *addr,
1799                                         const void *old_bytes,
1800                                         size_t old_len,
1801                                         const void *new_bytes,
1802                                         size_t new_len)                 { }
1803 static inline void perf_event_init(void)                                { }
1804 static inline int  perf_swevent_get_recursion_context(void)             { return -1; }
1805 static inline void perf_swevent_put_recursion_context(int rctx)         { }
1806 static inline u64 perf_swevent_set_period(struct perf_event *event)     { return 0; }
1807 static inline void perf_event_enable(struct perf_event *event)          { }
1808 static inline void perf_event_disable(struct perf_event *event)         { }
1809 static inline int __perf_event_disable(void *info)                      { return -1; }
1810 static inline void perf_event_task_tick(void)                           { }
1811 static inline int perf_event_release_kernel(struct perf_event *event)   { return 0; }
1812 static inline int perf_event_period(struct perf_event *event, u64 value)
1813 {
1814         return -EINVAL;
1815 }
1816 static inline u64 perf_event_pause(struct perf_event *event, bool reset)
1817 {
1818         return 0;
1819 }
1820 #endif
1821
1822 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL)
1823 extern void perf_restore_debug_store(void);
1824 #else
1825 static inline void perf_restore_debug_store(void)                       { }
1826 #endif
1827
1828 #define perf_output_put(handle, x) perf_output_copy((handle), &(x), sizeof(x))
1829
1830 struct perf_pmu_events_attr {
1831         struct device_attribute attr;
1832         u64 id;
1833         const char *event_str;
1834 };
1835
1836 struct perf_pmu_events_ht_attr {
1837         struct device_attribute                 attr;
1838         u64                                     id;
1839         const char                              *event_str_ht;
1840         const char                              *event_str_noht;
1841 };
1842
1843 struct perf_pmu_events_hybrid_attr {
1844         struct device_attribute                 attr;
1845         u64                                     id;
1846         const char                              *event_str;
1847         u64                                     pmu_type;
1848 };
1849
1850 struct perf_pmu_format_hybrid_attr {
1851         struct device_attribute                 attr;
1852         u64                                     pmu_type;
1853 };
1854
1855 ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr,
1856                               char *page);
1857
1858 #define PMU_EVENT_ATTR(_name, _var, _id, _show)                         \
1859 static struct perf_pmu_events_attr _var = {                             \
1860         .attr = __ATTR(_name, 0444, _show, NULL),                       \
1861         .id   =  _id,                                                   \
1862 };
1863
1864 #define PMU_EVENT_ATTR_STRING(_name, _var, _str)                            \
1865 static struct perf_pmu_events_attr _var = {                                 \
1866         .attr           = __ATTR(_name, 0444, perf_event_sysfs_show, NULL), \
1867         .id             = 0,                                                \
1868         .event_str      = _str,                                             \
1869 };
1870
1871 #define PMU_EVENT_ATTR_ID(_name, _show, _id)                            \
1872         (&((struct perf_pmu_events_attr[]) {                            \
1873                 { .attr = __ATTR(_name, 0444, _show, NULL),             \
1874                   .id = _id, }                                          \
1875         })[0].attr.attr)
1876
1877 #define PMU_FORMAT_ATTR_SHOW(_name, _format)                            \
1878 static ssize_t                                                          \
1879 _name##_show(struct device *dev,                                        \
1880                                struct device_attribute *attr,           \
1881                                char *page)                              \
1882 {                                                                       \
1883         BUILD_BUG_ON(sizeof(_format) >= PAGE_SIZE);                     \
1884         return sprintf(page, _format "\n");                             \
1885 }                                                                       \
1886
1887 #define PMU_FORMAT_ATTR(_name, _format)                                 \
1888         PMU_FORMAT_ATTR_SHOW(_name, _format)                            \
1889                                                                         \
1890 static struct device_attribute format_attr_##_name = __ATTR_RO(_name)
1891
1892 /* Performance counter hotplug functions */
1893 #ifdef CONFIG_PERF_EVENTS
1894 int perf_event_init_cpu(unsigned int cpu);
1895 int perf_event_exit_cpu(unsigned int cpu);
1896 #else
1897 #define perf_event_init_cpu     NULL
1898 #define perf_event_exit_cpu     NULL
1899 #endif
1900
1901 extern void arch_perf_update_userpage(struct perf_event *event,
1902                                       struct perf_event_mmap_page *userpg,
1903                                       u64 now);
1904
1905 /*
1906  * Snapshot branch stack on software events.
1907  *
1908  * Branch stack can be very useful in understanding software events. For
1909  * example, when a long function, e.g. sys_perf_event_open, returns an
1910  * errno, it is not obvious why the function failed. Branch stack could
1911  * provide very helpful information in this type of scenarios.
1912  *
1913  * On software event, it is necessary to stop the hardware branch recorder
1914  * fast. Otherwise, the hardware register/buffer will be flushed with
1915  * entries of the triggering event. Therefore, static call is used to
1916  * stop the hardware recorder.
1917  */
1918
1919 /*
1920  * cnt is the number of entries allocated for entries.
1921  * Return number of entries copied to .
1922  */
1923 typedef int (perf_snapshot_branch_stack_t)(struct perf_branch_entry *entries,
1924                                            unsigned int cnt);
1925 DECLARE_STATIC_CALL(perf_snapshot_branch_stack, perf_snapshot_branch_stack_t);
1926
1927 #ifndef PERF_NEEDS_LOPWR_CB
1928 static inline void perf_lopwr_cb(bool mode)
1929 {
1930 }
1931 #endif
1932
1933 #endif /* _LINUX_PERF_EVENT_H */