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