include/linux/perf_counter.h

   1 /*
   2  *  Performance counters:
   3  *
   4  *   Copyright(C) 2008, Thomas Gleixner <tglx@linutronix.de>
   5  *   Copyright(C) 2008, Red Hat, Inc., Ingo Molnar
   6  *
   7  *  Data type definitions, declarations, prototypes.
   8  *
   9  *  Started by: Thomas Gleixner and Ingo Molnar
  10  *
  11  *  For licencing details see kernel-base/COPYING
  12  */
  13 #ifndef _LINUX_PERF_COUNTER_H
  14 #define _LINUX_PERF_COUNTER_H
  15
  16 #include <linux/types.h>
  17 #include <linux/ioctl.h>
  18 #include <asm/byteorder.h>
  19
  20 /*
  21  * User-space ABI bits:
  22  */
  23
  24 /*
  25  * hw_event.type
  26  */
  27 enum perf_event_types {
  28         PERF_TYPE_HARDWARE              = 0,
  29         PERF_TYPE_SOFTWARE              = 1,
  30         PERF_TYPE_TRACEPOINT            = 2,
  31
  32         /*
  33          * available TYPE space, raw is the max value.
  34          */
  35
  36         PERF_TYPE_RAW                   = 128,
  37 };
  38
  39 /*
  40  * Generalized performance counter event types, used by the hw_event.event_id
  41  * parameter of the sys_perf_counter_open() syscall:
  42  */
  43 enum hw_event_ids {
  44         /*
  45          * Common hardware events, generalized by the kernel:
  46          */
  47         PERF_COUNT_CPU_CYCLES           = 0,
  48         PERF_COUNT_INSTRUCTIONS         = 1,
  49         PERF_COUNT_CACHE_REFERENCES     = 2,
  50         PERF_COUNT_CACHE_MISSES         = 3,
  51         PERF_COUNT_BRANCH_INSTRUCTIONS  = 4,
  52         PERF_COUNT_BRANCH_MISSES        = 5,
  53         PERF_COUNT_BUS_CYCLES           = 6,
  54
  55         PERF_HW_EVENTS_MAX              = 7,
  56 };
  57
  58 /*
  59  * Special "software" counters provided by the kernel, even if the hardware
  60  * does not support performance counters. These counters measure various
  61  * physical and sw events of the kernel (and allow the profiling of them as
  62  * well):
  63  */
  64 enum sw_event_ids {
  65         PERF_COUNT_CPU_CLOCK            = 0,
  66         PERF_COUNT_TASK_CLOCK           = 1,
  67         PERF_COUNT_PAGE_FAULTS          = 2,
  68         PERF_COUNT_CONTEXT_SWITCHES     = 3,
  69         PERF_COUNT_CPU_MIGRATIONS       = 4,
  70         PERF_COUNT_PAGE_FAULTS_MIN      = 5,
  71         PERF_COUNT_PAGE_FAULTS_MAJ      = 6,
  72
  73         PERF_SW_EVENTS_MAX              = 7,
  74 };
  75
  76 #define __PERF_COUNTER_MASK(name)                       \
  77         (((1ULL << PERF_COUNTER_##name##_BITS) - 1) <<  \
  78          PERF_COUNTER_##name##_SHIFT)
  79
  80 #define PERF_COUNTER_RAW_BITS           1
  81 #define PERF_COUNTER_RAW_SHIFT          63
  82 #define PERF_COUNTER_RAW_MASK           __PERF_COUNTER_MASK(RAW)
  83
  84 #define PERF_COUNTER_CONFIG_BITS        63
  85 #define PERF_COUNTER_CONFIG_SHIFT       0
  86 #define PERF_COUNTER_CONFIG_MASK        __PERF_COUNTER_MASK(CONFIG)
  87
  88 #define PERF_COUNTER_TYPE_BITS          7
  89 #define PERF_COUNTER_TYPE_SHIFT         56
  90 #define PERF_COUNTER_TYPE_MASK          __PERF_COUNTER_MASK(TYPE)
  91
  92 #define PERF_COUNTER_EVENT_BITS         56
  93 #define PERF_COUNTER_EVENT_SHIFT        0
  94 #define PERF_COUNTER_EVENT_MASK         __PERF_COUNTER_MASK(EVENT)
  95
  96 /*
  97  * Bits that can be set in hw_event.record_type to request information
  98  * in the overflow packets.
  99  */
 100 enum perf_counter_record_format {
 101         PERF_RECORD_IP          = 1U << 0,
 102         PERF_RECORD_TID         = 1U << 1,
 103         PERF_RECORD_TIME        = 1U << 2,
 104         PERF_RECORD_ADDR        = 1U << 3,
 105         PERF_RECORD_GROUP       = 1U << 4,
 106         PERF_RECORD_CALLCHAIN   = 1U << 5,
 107 };
 108
 109 /*
 110  * Bits that can be set in hw_event.read_format to request that
 111  * reads on the counter should return the indicated quantities,
 112  * in increasing order of bit value, after the counter value.
 113  */
 114 enum perf_counter_read_format {
 115         PERF_FORMAT_TOTAL_TIME_ENABLED  =  1,
 116         PERF_FORMAT_TOTAL_TIME_RUNNING  =  2,
 117 };
 118
 119 /*
 120  * Hardware event to monitor via a performance monitoring counter:
 121  */
 122 struct perf_counter_hw_event {
 123         /*
 124          * The MSB of the config word signifies if the rest contains cpu
 125          * specific (raw) counter configuration data, if unset, the next
 126          * 7 bits are an event type and the rest of the bits are the event
 127          * identifier.
 128          */
 129         __u64                   config;
 130
 131         __u64                   irq_period;
 132         __u32                   record_type;
 133         __u32                   read_format;
 134
 135         __u64                   disabled       :  1, /* off by default        */
 136                                 nmi            :  1, /* NMI sampling          */
 137                                 inherit        :  1, /* children inherit it   */
 138                                 pinned         :  1, /* must always be on PMU */
 139                                 exclusive      :  1, /* only group on PMU     */
 140                                 exclude_user   :  1, /* don't count user      */
 141                                 exclude_kernel :  1, /* ditto kernel          */
 142                                 exclude_hv     :  1, /* ditto hypervisor      */
 143                                 exclude_idle   :  1, /* don't count when idle */
 144                                 mmap           :  1, /* include mmap data     */
 145                                 munmap         :  1, /* include munmap data   */
 146                                 comm           :  1, /* include comm data     */
 147
 148                                 __reserved_1   : 52;
 149
 150         __u32                   extra_config_len;
 151         __u32                   wakeup_events;  /* wakeup every n events */
 152
 153         __u64                   __reserved_2;
 154         __u64                   __reserved_3;
 155 };
 156
 157 /*
 158  * Ioctls that can be done on a perf counter fd:
 159  */
 160 #define PERF_COUNTER_IOC_ENABLE         _IO ('$', 0)
 161 #define PERF_COUNTER_IOC_DISABLE        _IO ('$', 1)
 162 #define PERF_COUNTER_IOC_REFRESH        _IOW('$', 2, u32)
 163 #define PERF_COUNTER_IOC_RESET          _IO ('$', 3)
 164
 165 /*
 166  * Structure of the page that can be mapped via mmap
 167  */
 168 struct perf_counter_mmap_page {
 169         __u32   version;                /* version number of this structure */
 170         __u32   compat_version;         /* lowest version this is compat with */
 171
 172         /*
 173          * Bits needed to read the hw counters in user-space.
 174          *
 175          *   u32 seq;
 176          *   s64 count;
 177          *
 178          *   do {
 179          *     seq = pc->lock;
 180          *
 181          *     barrier()
 182          *     if (pc->index) {
 183          *       count = pmc_read(pc->index - 1);
 184          *       count += pc->offset;
 185          *     } else
 186          *       goto regular_read;
 187          *
 188          *     barrier();
 189          *   } while (pc->lock != seq);
 190          *
 191          * NOTE: for obvious reason this only works on self-monitoring
 192          *       processes.
 193          */
 194         __u32   lock;                   /* seqlock for synchronization */
 195         __u32   index;                  /* hardware counter identifier */
 196         __s64   offset;                 /* add to hardware counter value */
 197
 198         /*
 199          * Control data for the mmap() data buffer.
 200          *
 201          * User-space reading this value should issue an rmb(), on SMP capable
 202          * platforms, after reading this value -- see perf_counter_wakeup().
 203          */
 204         __u32   data_head;              /* head in the data section */
 205 };
 206
 207 #define PERF_EVENT_MISC_KERNEL          (1 << 0)
 208 #define PERF_EVENT_MISC_USER            (1 << 1)
 209 #define PERF_EVENT_MISC_OVERFLOW        (1 << 2)
 210
 211 struct perf_event_header {
 212         __u32   type;
 213         __u16   misc;
 214         __u16   size;
 215 };
 216
 217 enum perf_event_type {
 218
 219         /*
 220          * The MMAP events record the PROT_EXEC mappings so that we can
 221          * correlate userspace IPs to code. They have the following structure:
 222          *
 223          * struct {
 224          *      struct perf_event_header        header;
 225          *
 226          *      u32                             pid, tid;
 227          *      u64                             addr;
 228          *      u64                             len;
 229          *      u64                             pgoff;
 230          *      char                            filename[];
 231          * };
 232          */
 233         PERF_EVENT_MMAP                 = 1,
 234         PERF_EVENT_MUNMAP               = 2,
 235
 236         /*
 237          * struct {
 238          *      struct perf_event_header        header;
 239          *
 240          *      u32                             pid, tid;
 241          *      char                            comm[];
 242          * };
 243          */
 244         PERF_EVENT_COMM                 = 3,
 245
 246         /*
 247          * When header.misc & PERF_EVENT_MISC_OVERFLOW the event_type field
 248          * will be PERF_RECORD_*
 249          *
 250          * struct {
 251          *      struct perf_event_header        header;
 252          *
 253          *      { u64                   ip;       } && PERF_RECORD_IP
 254          *      { u32                   pid, tid; } && PERF_RECORD_TID
 255          *      { u64                   time;     } && PERF_RECORD_TIME
 256          *      { u64                   addr;     } && PERF_RECORD_ADDR
 257          *
 258          *      { u64                   nr;
 259          *        { u64 event, val; }   cnt[nr];  } && PERF_RECORD_GROUP
 260          *
 261          *      { u16                   nr,
 262          *                              hv,
 263          *                              kernel,
 264          *                              user;
 265          *        u64                   ips[nr];  } && PERF_RECORD_CALLCHAIN
 266          * };
 267          */
 268 };
 269
 270 #ifdef __KERNEL__
 271 /*
 272  * Kernel-internal data types and definitions:
 273  */
 274
 275 #ifdef CONFIG_PERF_COUNTERS
 276 # include <asm/perf_counter.h>
 277 #endif
 278
 279 #include <linux/list.h>
 280 #include <linux/mutex.h>
 281 #include <linux/rculist.h>
 282 #include <linux/rcupdate.h>
 283 #include <linux/spinlock.h>
 284 #include <linux/hrtimer.h>
 285 #include <linux/fs.h>
 286 #include <asm/atomic.h>
 287
 288 struct task_struct;
 289
 290 static inline u64 perf_event_raw(struct perf_counter_hw_event *hw_event)
 291 {
 292         return hw_event->config & PERF_COUNTER_RAW_MASK;
 293 }
 294
 295 static inline u64 perf_event_config(struct perf_counter_hw_event *hw_event)
 296 {
 297         return hw_event->config & PERF_COUNTER_CONFIG_MASK;
 298 }
 299
 300 static inline u64 perf_event_type(struct perf_counter_hw_event *hw_event)
 301 {
 302         return (hw_event->config & PERF_COUNTER_TYPE_MASK) >>
 303                 PERF_COUNTER_TYPE_SHIFT;
 304 }
 305
 306 static inline u64 perf_event_id(struct perf_counter_hw_event *hw_event)
 307 {
 308         return hw_event->config & PERF_COUNTER_EVENT_MASK;
 309 }
 310
 311 /**
 312  * struct hw_perf_counter - performance counter hardware details:
 313  */
 314 struct hw_perf_counter {
 315 #ifdef CONFIG_PERF_COUNTERS
 316         union {
 317                 struct { /* hardware */
 318                         u64                             config;
 319                         unsigned long                   config_base;
 320                         unsigned long                   counter_base;
 321                         int                             nmi;
 322                         int                             idx;
 323                 };
 324                 union { /* software */
 325                         atomic64_t                      count;
 326                         struct hrtimer                  hrtimer;
 327                 };
 328         };
 329         atomic64_t                      prev_count;
 330         u64                             irq_period;
 331         atomic64_t                      period_left;
 332 #endif
 333 };
 334
 335 struct perf_counter;
 336
 337 /**
 338  * struct pmu - generic performance monitoring unit
 339  */
 340 struct pmu {
 341         int (*enable)                   (struct perf_counter *counter);
 342         void (*disable)                 (struct perf_counter *counter);
 343         void (*read)                    (struct perf_counter *counter);
 344 };
 345
 346 /**
 347  * enum perf_counter_active_state - the states of a counter
 348  */
 349 enum perf_counter_active_state {
 350         PERF_COUNTER_STATE_ERROR        = -2,
 351         PERF_COUNTER_STATE_OFF          = -1,
 352         PERF_COUNTER_STATE_INACTIVE     =  0,
 353         PERF_COUNTER_STATE_ACTIVE       =  1,
 354 };
 355
 356 struct file;
 357
 358 struct perf_mmap_data {
 359         struct rcu_head                 rcu_head;
 360         int                             nr_pages;       /* nr of data pages  */
 361         int                             nr_locked;      /* nr pages mlocked  */
 362
 363         atomic_t                        poll;           /* POLL_ for wakeups */
 364         atomic_t                        head;           /* write position    */
 365         atomic_t                        events;         /* event limit       */
 366
 367         atomic_t                        done_head;      /* completed head    */
 368         atomic_t                        lock;           /* concurrent writes */
 369
 370         atomic_t                        wakeup;         /* needs a wakeup    */
 371
 372         struct perf_counter_mmap_page   *user_page;
 373         void                            *data_pages[0];
 374 };
 375
 376 struct perf_pending_entry {
 377         struct perf_pending_entry *next;
 378         void (*func)(struct perf_pending_entry *);
 379 };
 380
 381 /**
 382  * struct perf_counter - performance counter kernel representation:
 383  */
 384 struct perf_counter {
 385 #ifdef CONFIG_PERF_COUNTERS
 386         struct list_head                list_entry;
 387         struct list_head                event_entry;
 388         struct list_head                sibling_list;
 389         int                             nr_siblings;
 390         struct perf_counter             *group_leader;
 391         const struct pmu                *pmu;
 392
 393         enum perf_counter_active_state  state;
 394         enum perf_counter_active_state  prev_state;
 395         atomic64_t                      count;
 396
 397         /*
 398          * These are the total time in nanoseconds that the counter
 399          * has been enabled (i.e. eligible to run, and the task has
 400          * been scheduled in, if this is a per-task counter)
 401          * and running (scheduled onto the CPU), respectively.
 402          *
 403          * They are computed from tstamp_enabled, tstamp_running and
 404          * tstamp_stopped when the counter is in INACTIVE or ACTIVE state.
 405          */
 406         u64                             total_time_enabled;
 407         u64                             total_time_running;
 408
 409         /*
 410          * These are timestamps used for computing total_time_enabled
 411          * and total_time_running when the counter is in INACTIVE or
 412          * ACTIVE state, measured in nanoseconds from an arbitrary point
 413          * in time.
 414          * tstamp_enabled: the notional time when the counter was enabled
 415          * tstamp_running: the notional time when the counter was scheduled on
 416          * tstamp_stopped: in INACTIVE state, the notional time when the
 417          *      counter was scheduled off.
 418          */
 419         u64                             tstamp_enabled;
 420         u64                             tstamp_running;
 421         u64                             tstamp_stopped;
 422
 423         struct perf_counter_hw_event    hw_event;
 424         struct hw_perf_counter          hw;
 425
 426         struct perf_counter_context     *ctx;
 427         struct task_struct              *task;
 428         struct file                     *filp;
 429
 430         struct perf_counter             *parent;
 431         struct list_head                child_list;
 432
 433         /*
 434          * These accumulate total time (in nanoseconds) that children
 435          * counters have been enabled and running, respectively.
 436          */
 437         atomic64_t                      child_total_time_enabled;
 438         atomic64_t                      child_total_time_running;
 439
 440         /*
 441          * Protect attach/detach and child_list:
 442          */
 443         struct mutex                    mutex;
 444
 445         int                             oncpu;
 446         int                             cpu;
 447
 448         /* mmap bits */
 449         struct mutex                    mmap_mutex;
 450         atomic_t                        mmap_count;
 451         struct perf_mmap_data           *data;
 452
 453         /* poll related */
 454         wait_queue_head_t               waitq;
 455         struct fasync_struct            *fasync;
 456
 457         /* delayed work for NMIs and such */
 458         int                             pending_wakeup;
 459         int                             pending_kill;
 460         int                             pending_disable;
 461         struct perf_pending_entry       pending;
 462
 463         atomic_t                        event_limit;
 464
 465         void (*destroy)(struct perf_counter *);
 466         struct rcu_head                 rcu_head;
 467 #endif
 468 };
 469
 470 /**
 471  * struct perf_counter_context - counter context structure
 472  *
 473  * Used as a container for task counters and CPU counters as well:
 474  */
 475 struct perf_counter_context {
 476 #ifdef CONFIG_PERF_COUNTERS
 477         /*
 478          * Protect the states of the counters in the list,
 479          * nr_active, and the list:
 480          */
 481         spinlock_t              lock;
 482         /*
 483          * Protect the list of counters.  Locking either mutex or lock
 484          * is sufficient to ensure the list doesn't change; to change
 485          * the list you need to lock both the mutex and the spinlock.
 486          */
 487         struct mutex            mutex;
 488
 489         struct list_head        counter_list;
 490         struct list_head        event_list;
 491         int                     nr_counters;
 492         int                     nr_active;
 493         int                     is_active;
 494         struct task_struct      *task;
 495
 496         /*
 497          * Context clock, runs when context enabled.
 498          */
 499         u64                     time;
 500         u64                     timestamp;
 501 #endif
 502 };
 503
 504 /**
 505  * struct perf_counter_cpu_context - per cpu counter context structure
 506  */
 507 struct perf_cpu_context {
 508         struct perf_counter_context     ctx;
 509         struct perf_counter_context     *task_ctx;
 510         int                             active_oncpu;
 511         int                             max_pertask;
 512         int                             exclusive;
 513
 514         /*
 515          * Recursion avoidance:
 516          *
 517          * task, softirq, irq, nmi context
 518          */
 519         int                     recursion[4];
 520 };
 521
 522 #ifdef CONFIG_PERF_COUNTERS
 523
 524 /*
 525  * Set by architecture code:
 526  */
 527 extern int perf_max_counters;
 528
 529 extern const struct pmu *hw_perf_counter_init(struct perf_counter *counter);
 530
 531 extern void perf_counter_task_sched_in(struct task_struct *task, int cpu);
 532 extern void perf_counter_task_sched_out(struct task_struct *task, int cpu);
 533 extern void perf_counter_task_tick(struct task_struct *task, int cpu);
 534 extern void perf_counter_init_task(struct task_struct *child);
 535 extern void perf_counter_exit_task(struct task_struct *child);
 536 extern void perf_counter_do_pending(void);
 537 extern void perf_counter_print_debug(void);
 538 extern void perf_counter_unthrottle(void);
 539 extern u64 hw_perf_save_disable(void);
 540 extern void hw_perf_restore(u64 ctrl);
 541 extern int perf_counter_task_disable(void);
 542 extern int perf_counter_task_enable(void);
 543 extern int hw_perf_group_sched_in(struct perf_counter *group_leader,
 544                struct perf_cpu_context *cpuctx,
 545                struct perf_counter_context *ctx, int cpu);
 546 extern void perf_counter_update_userpage(struct perf_counter *counter);
 547
 548 extern int perf_counter_overflow(struct perf_counter *counter,
 549                                  int nmi, struct pt_regs *regs, u64 addr);
 550 /*
 551  * Return 1 for a software counter, 0 for a hardware counter
 552  */
 553 static inline int is_software_counter(struct perf_counter *counter)
 554 {
 555         return !perf_event_raw(&counter->hw_event) &&
 556                 perf_event_type(&counter->hw_event) != PERF_TYPE_HARDWARE;
 557 }
 558
 559 extern void perf_swcounter_event(u32, u64, int, struct pt_regs *, u64);
 560
 561 extern void perf_counter_mmap(unsigned long addr, unsigned long len,
 562                               unsigned long pgoff, struct file *file);
 563
 564 extern void perf_counter_munmap(unsigned long addr, unsigned long len,
 565                                 unsigned long pgoff, struct file *file);
 566
 567 extern void perf_counter_comm(struct task_struct *tsk);
 568
 569 #define MAX_STACK_DEPTH         255
 570
 571 struct perf_callchain_entry {
 572         u16     nr, hv, kernel, user;
 573         u64     ip[MAX_STACK_DEPTH];
 574 };
 575
 576 extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs);
 577
 578 extern int sysctl_perf_counter_priv;
 579 extern int sysctl_perf_counter_mlock;
 580
 581 extern void perf_counter_init(void);
 582
 583 #else
 584 static inline void
 585 perf_counter_task_sched_in(struct task_struct *task, int cpu)           { }
 586 static inline void
 587 perf_counter_task_sched_out(struct task_struct *task, int cpu)          { }
 588 static inline void
 589 perf_counter_task_tick(struct task_struct *task, int cpu)               { }
 590 static inline void perf_counter_init_task(struct task_struct *child)    { }
 591 static inline void perf_counter_exit_task(struct task_struct *child)    { }
 592 static inline void perf_counter_do_pending(void)                        { }
 593 static inline void perf_counter_print_debug(void)                       { }
 594 static inline void perf_counter_unthrottle(void)                        { }
 595 static inline void hw_perf_restore(u64 ctrl)                            { }
 596 static inline u64 hw_perf_save_disable(void)                  { return 0; }
 597 static inline int perf_counter_task_disable(void)       { return -EINVAL; }
 598 static inline int perf_counter_task_enable(void)        { return -EINVAL; }
 599
 600 static inline void
 601 perf_swcounter_event(u32 event, u64 nr, int nmi,
 602                      struct pt_regs *regs, u64 addr)                    { }
 603
 604 static inline void
 605 perf_counter_mmap(unsigned long addr, unsigned long len,
 606                   unsigned long pgoff, struct file *file)               { }
 607
 608 static inline void
 609 perf_counter_munmap(unsigned long addr, unsigned long len,
 610                     unsigned long pgoff, struct file *file)             { }
 611
 612 static inline void perf_counter_comm(struct task_struct *tsk)           { }
 613 static inline void perf_counter_init(void)                              { }
 614 #endif
 615
 616 #endif /* __KERNEL__ */
 617 #endif /* _LINUX_PERF_COUNTER_H */