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
  19 /*
  20  * User-space ABI bits:
  21  */
  22
  23 /*
  24  * Generalized performance counter event types, used by the hw_event.type
  25  * parameter of the sys_perf_counter_open() syscall:
  26  */
  27 enum hw_event_types {
  28         /*
  29          * Common hardware events, generalized by the kernel:
  30          */
  31         PERF_COUNT_CPU_CYCLES           =  0,
  32         PERF_COUNT_INSTRUCTIONS         =  1,
  33         PERF_COUNT_CACHE_REFERENCES     =  2,
  34         PERF_COUNT_CACHE_MISSES         =  3,
  35         PERF_COUNT_BRANCH_INSTRUCTIONS  =  4,
  36         PERF_COUNT_BRANCH_MISSES        =  5,
  37         PERF_COUNT_BUS_CYCLES           =  6,
  38
  39         PERF_HW_EVENTS_MAX              =  7,
  40
  41         /*
  42          * Special "software" counters provided by the kernel, even if
  43          * the hardware does not support performance counters. These
  44          * counters measure various physical and sw events of the
  45          * kernel (and allow the profiling of them as well):
  46          */
  47         PERF_COUNT_CPU_CLOCK            = -1,
  48         PERF_COUNT_TASK_CLOCK           = -2,
  49         PERF_COUNT_PAGE_FAULTS          = -3,
  50         PERF_COUNT_CONTEXT_SWITCHES     = -4,
  51         PERF_COUNT_CPU_MIGRATIONS       = -5,
  52         PERF_COUNT_PAGE_FAULTS_MIN      = -6,
  53         PERF_COUNT_PAGE_FAULTS_MAJ      = -7,
  54
  55         PERF_SW_EVENTS_MIN              = -8,
  56
  57         PERF_TP_EVENTS_MIN              = -65536
  58 };
  59
  60 /*
  61  * IRQ-notification data record type:
  62  */
  63 enum perf_counter_record_type {
  64         PERF_RECORD_SIMPLE              =  0,
  65         PERF_RECORD_IRQ                 =  1,
  66         PERF_RECORD_GROUP               =  2,
  67 };
  68
  69 /*
  70  * Hardware event to monitor via a performance monitoring counter:
  71  */
  72 struct perf_counter_hw_event {
  73         __s64                   type;
  74
  75         __u64                   irq_period;
  76         __u64                   record_type;
  77         __u64                   read_format;
  78
  79         __u64                   disabled       :  1, /* off by default        */
  80                                 nmi            :  1, /* NMI sampling          */
  81                                 raw            :  1, /* raw event type        */
  82                                 inherit        :  1, /* children inherit it   */
  83                                 pinned         :  1, /* must always be on PMU */
  84                                 exclusive      :  1, /* only group on PMU     */
  85                                 exclude_user   :  1, /* don't count user      */
  86                                 exclude_kernel :  1, /* ditto kernel          */
  87                                 exclude_hv     :  1, /* ditto hypervisor      */
  88                                 exclude_idle   :  1, /* don't count when idle */
  89
  90                                 __reserved_1   : 54;
  91
  92         __u32                   extra_config_len;
  93         __u32                   __reserved_4;
  94
  95         __u64                   __reserved_2;
  96         __u64                   __reserved_3;
  97 };
  98
  99 /*
 100  * Ioctls that can be done on a perf counter fd:
 101  */
 102 #define PERF_COUNTER_IOC_ENABLE         _IO('$', 0)
 103 #define PERF_COUNTER_IOC_DISABLE        _IO('$', 1)
 104
 105 #ifdef __KERNEL__
 106 /*
 107  * Kernel-internal data types and definitions:
 108  */
 109
 110 #ifdef CONFIG_PERF_COUNTERS
 111 # include <asm/perf_counter.h>
 112 #endif
 113
 114 #include <linux/list.h>
 115 #include <linux/mutex.h>
 116 #include <linux/rculist.h>
 117 #include <linux/rcupdate.h>
 118 #include <linux/spinlock.h>
 119 #include <linux/hrtimer.h>
 120 #include <asm/atomic.h>
 121
 122 struct task_struct;
 123
 124 /**
 125  * struct hw_perf_counter - performance counter hardware details:
 126  */
 127 struct hw_perf_counter {
 128 #ifdef CONFIG_PERF_COUNTERS
 129         union {
 130                 struct { /* hardware */
 131                         u64                             config;
 132                         unsigned long                   config_base;
 133                         unsigned long                   counter_base;
 134                         int                             nmi;
 135                         unsigned int                    idx;
 136                 };
 137                 union { /* software */
 138                         atomic64_t                      count;
 139                         struct hrtimer                  hrtimer;
 140                 };
 141         };
 142         atomic64_t                      prev_count;
 143         u64                             irq_period;
 144         atomic64_t                      period_left;
 145 #endif
 146 };
 147
 148 /*
 149  * Hardcoded buffer length limit for now, for IRQ-fed events:
 150  */
 151 #define PERF_DATA_BUFLEN                2048
 152
 153 /**
 154  * struct perf_data - performance counter IRQ data sampling ...
 155  */
 156 struct perf_data {
 157         int                             len;
 158         int                             rd_idx;
 159         int                             overrun;
 160         u8                              data[PERF_DATA_BUFLEN];
 161 };
 162
 163 struct perf_counter;
 164
 165 /**
 166  * struct hw_perf_counter_ops - performance counter hw ops
 167  */
 168 struct hw_perf_counter_ops {
 169         int (*enable)                   (struct perf_counter *counter);
 170         void (*disable)                 (struct perf_counter *counter);
 171         void (*read)                    (struct perf_counter *counter);
 172 };
 173
 174 /**
 175  * enum perf_counter_active_state - the states of a counter
 176  */
 177 enum perf_counter_active_state {
 178         PERF_COUNTER_STATE_ERROR        = -2,
 179         PERF_COUNTER_STATE_OFF          = -1,
 180         PERF_COUNTER_STATE_INACTIVE     =  0,
 181         PERF_COUNTER_STATE_ACTIVE       =  1,
 182 };
 183
 184 struct file;
 185
 186 /**
 187  * struct perf_counter - performance counter kernel representation:
 188  */
 189 struct perf_counter {
 190 #ifdef CONFIG_PERF_COUNTERS
 191         struct list_head                list_entry;
 192         struct list_head                event_entry;
 193         struct list_head                sibling_list;
 194         struct perf_counter             *group_leader;
 195         const struct hw_perf_counter_ops *hw_ops;
 196
 197         enum perf_counter_active_state  state;
 198         enum perf_counter_active_state  prev_state;
 199         atomic64_t                      count;
 200
 201         struct perf_counter_hw_event    hw_event;
 202         struct hw_perf_counter          hw;
 203
 204         struct perf_counter_context     *ctx;
 205         struct task_struct              *task;
 206         struct file                     *filp;
 207
 208         struct perf_counter             *parent;
 209         struct list_head                child_list;
 210
 211         /*
 212          * Protect attach/detach and child_list:
 213          */
 214         struct mutex                    mutex;
 215
 216         int                             oncpu;
 217         int                             cpu;
 218
 219         /* read() / irq related data */
 220         wait_queue_head_t               waitq;
 221         /* optional: for NMIs */
 222         int                             wakeup_pending;
 223         struct perf_data                *irqdata;
 224         struct perf_data                *usrdata;
 225         struct perf_data                data[2];
 226
 227         void (*destroy)(struct perf_counter *);
 228         struct rcu_head                 rcu_head;
 229 #endif
 230 };
 231
 232 /**
 233  * struct perf_counter_context - counter context structure
 234  *
 235  * Used as a container for task counters and CPU counters as well:
 236  */
 237 struct perf_counter_context {
 238 #ifdef CONFIG_PERF_COUNTERS
 239         /*
 240          * Protect the states of the counters in the list,
 241          * nr_active, and the list:
 242          */
 243         spinlock_t              lock;
 244         /*
 245          * Protect the list of counters.  Locking either mutex or lock
 246          * is sufficient to ensure the list doesn't change; to change
 247          * the list you need to lock both the mutex and the spinlock.
 248          */
 249         struct mutex            mutex;
 250
 251         struct list_head        counter_list;
 252         struct list_head        event_list;
 253         int                     nr_counters;
 254         int                     nr_active;
 255         int                     is_active;
 256         struct task_struct      *task;
 257 #endif
 258 };
 259
 260 /**
 261  * struct perf_counter_cpu_context - per cpu counter context structure
 262  */
 263 struct perf_cpu_context {
 264         struct perf_counter_context     ctx;
 265         struct perf_counter_context     *task_ctx;
 266         int                             active_oncpu;
 267         int                             max_pertask;
 268         int                             exclusive;
 269 };
 270
 271 /*
 272  * Set by architecture code:
 273  */
 274 extern int perf_max_counters;
 275
 276 #ifdef CONFIG_PERF_COUNTERS
 277 extern const struct hw_perf_counter_ops *
 278 hw_perf_counter_init(struct perf_counter *counter);
 279
 280 extern void perf_counter_task_sched_in(struct task_struct *task, int cpu);
 281 extern void perf_counter_task_sched_out(struct task_struct *task, int cpu);
 282 extern void perf_counter_task_tick(struct task_struct *task, int cpu);
 283 extern void perf_counter_init_task(struct task_struct *child);
 284 extern void perf_counter_exit_task(struct task_struct *child);
 285 extern void perf_counter_notify(struct pt_regs *regs);
 286 extern void perf_counter_print_debug(void);
 287 extern void perf_counter_unthrottle(void);
 288 extern u64 hw_perf_save_disable(void);
 289 extern void hw_perf_restore(u64 ctrl);
 290 extern int perf_counter_task_disable(void);
 291 extern int perf_counter_task_enable(void);
 292 extern int hw_perf_group_sched_in(struct perf_counter *group_leader,
 293                struct perf_cpu_context *cpuctx,
 294                struct perf_counter_context *ctx, int cpu);
 295
 296 /*
 297  * Return 1 for a software counter, 0 for a hardware counter
 298  */
 299 static inline int is_software_counter(struct perf_counter *counter)
 300 {
 301         return !counter->hw_event.raw && counter->hw_event.type < 0;
 302 }
 303
 304 extern void perf_swcounter_event(enum hw_event_types, u64, int, struct pt_regs *);
 305
 306 #else
 307 static inline void
 308 perf_counter_task_sched_in(struct task_struct *task, int cpu)           { }
 309 static inline void
 310 perf_counter_task_sched_out(struct task_struct *task, int cpu)          { }
 311 static inline void
 312 perf_counter_task_tick(struct task_struct *task, int cpu)               { }
 313 static inline void perf_counter_init_task(struct task_struct *child)    { }
 314 static inline void perf_counter_exit_task(struct task_struct *child)    { }
 315 static inline void perf_counter_notify(struct pt_regs *regs)            { }
 316 static inline void perf_counter_print_debug(void)                       { }
 317 static inline void perf_counter_unthrottle(void)                        { }
 318 static inline void hw_perf_restore(u64 ctrl)                            { }
 319 static inline u64 hw_perf_save_disable(void)                  { return 0; }
 320 static inline int perf_counter_task_disable(void)       { return -EINVAL; }
 321 static inline int perf_counter_task_enable(void)        { return -EINVAL; }
 322
 323 static inline void perf_swcounter_event(enum hw_event_types event, u64 nr,
 324                                         int nmi, struct pt_regs *regs)  { }
 325 #endif
 326
 327 #endif /* __KERNEL__ */
 328 #endif /* _LINUX_PERF_COUNTER_H */