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