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         __u32                   record_type;
  73
  74         __u32                   disabled       :  1, /* off by default        */
  75                                 nmi            :  1, /* NMI sampling          */
  76                                 raw            :  1, /* raw event type        */
  77                                 inherit        :  1, /* children inherit it   */
  78                                 pinned         :  1, /* must always be on PMU */
  79                                 exclusive      :  1, /* only group on PMU     */
  80                                 exclude_user   :  1, /* don't count user      */
  81                                 exclude_kernel :  1, /* ditto kernel          */
  82                                 exclude_hv     :  1, /* ditto hypervisor      */
  83
  84                                 __reserved_1 : 23;
  85
  86         __u64                   __reserved_2;
  87 };
  88
  89 /*
  90  * Ioctls that can be done on a perf counter fd:
  91  */
  92 #define PERF_COUNTER_IOC_ENABLE         _IO('$', 0)
  93 #define PERF_COUNTER_IOC_DISABLE        _IO('$', 1)
  94
  95 #ifdef __KERNEL__
  96 /*
  97  * Kernel-internal data types and definitions:
  98  */
  99
 100 #ifdef CONFIG_PERF_COUNTERS
 101 # include <asm/perf_counter.h>
 102 #endif
 103
 104 #include <linux/list.h>
 105 #include <linux/mutex.h>
 106 #include <linux/rculist.h>
 107 #include <linux/rcupdate.h>
 108 #include <linux/spinlock.h>
 109 #include <asm/atomic.h>
 110
 111 struct task_struct;
 112
 113 /**
 114  * struct hw_perf_counter - performance counter hardware details:
 115  */
 116 struct hw_perf_counter {
 117 #ifdef CONFIG_PERF_COUNTERS
 118         u64                             config;
 119         unsigned long                   config_base;
 120         unsigned long                   counter_base;
 121         int                             nmi;
 122         unsigned int                    idx;
 123         atomic64_t                      prev_count;
 124         u64                             irq_period;
 125         atomic64_t                      period_left;
 126 #endif
 127 };
 128
 129 /*
 130  * Hardcoded buffer length limit for now, for IRQ-fed events:
 131  */
 132 #define PERF_DATA_BUFLEN                2048
 133
 134 /**
 135  * struct perf_data - performance counter IRQ data sampling ...
 136  */
 137 struct perf_data {
 138         int                             len;
 139         int                             rd_idx;
 140         int                             overrun;
 141         u8                              data[PERF_DATA_BUFLEN];
 142 };
 143
 144 struct perf_counter;
 145
 146 /**
 147  * struct hw_perf_counter_ops - performance counter hw ops
 148  */
 149 struct hw_perf_counter_ops {
 150         int (*enable)                   (struct perf_counter *counter);
 151         void (*disable)                 (struct perf_counter *counter);
 152         void (*read)                    (struct perf_counter *counter);
 153 };
 154
 155 /**
 156  * enum perf_counter_active_state - the states of a counter
 157  */
 158 enum perf_counter_active_state {
 159         PERF_COUNTER_STATE_ERROR        = -2,
 160         PERF_COUNTER_STATE_OFF          = -1,
 161         PERF_COUNTER_STATE_INACTIVE     =  0,
 162         PERF_COUNTER_STATE_ACTIVE       =  1,
 163 };
 164
 165 struct file;
 166
 167 /**
 168  * struct perf_counter - performance counter kernel representation:
 169  */
 170 struct perf_counter {
 171 #ifdef CONFIG_PERF_COUNTERS
 172         struct list_head                list_entry;
 173         struct list_head                sibling_list;
 174         struct perf_counter             *group_leader;
 175         const struct hw_perf_counter_ops *hw_ops;
 176
 177         enum perf_counter_active_state  state;
 178         enum perf_counter_active_state  prev_state;
 179         atomic64_t                      count;
 180
 181         struct perf_counter_hw_event    hw_event;
 182         struct hw_perf_counter          hw;
 183
 184         struct perf_counter_context     *ctx;
 185         struct task_struct              *task;
 186         struct file                     *filp;
 187
 188         struct perf_counter             *parent;
 189         struct list_head                child_list;
 190
 191         /*
 192          * Protect attach/detach and child_list:
 193          */
 194         struct mutex                    mutex;
 195
 196         int                             oncpu;
 197         int                             cpu;
 198
 199         /* read() / irq related data */
 200         wait_queue_head_t               waitq;
 201         /* optional: for NMIs */
 202         int                             wakeup_pending;
 203         struct perf_data                *irqdata;
 204         struct perf_data                *usrdata;
 205         struct perf_data                data[2];
 206 #endif
 207 };
 208
 209 /**
 210  * struct perf_counter_context - counter context structure
 211  *
 212  * Used as a container for task counters and CPU counters as well:
 213  */
 214 struct perf_counter_context {
 215 #ifdef CONFIG_PERF_COUNTERS
 216         /*
 217          * Protect the states of the counters in the list,
 218          * nr_active, and the list:
 219          */
 220         spinlock_t              lock;
 221         /*
 222          * Protect the list of counters.  Locking either mutex or lock
 223          * is sufficient to ensure the list doesn't change; to change
 224          * the list you need to lock both the mutex and the spinlock.
 225          */
 226         struct mutex            mutex;
 227
 228         struct list_head        counter_list;
 229         int                     nr_counters;
 230         int                     nr_active;
 231         int                     is_active;
 232         struct task_struct      *task;
 233 #endif
 234 };
 235
 236 /**
 237  * struct perf_counter_cpu_context - per cpu counter context structure
 238  */
 239 struct perf_cpu_context {
 240         struct perf_counter_context     ctx;
 241         struct perf_counter_context     *task_ctx;
 242         int                             active_oncpu;
 243         int                             max_pertask;
 244         int                             exclusive;
 245 };
 246
 247 /*
 248  * Set by architecture code:
 249  */
 250 extern int perf_max_counters;
 251
 252 #ifdef CONFIG_PERF_COUNTERS
 253 extern const struct hw_perf_counter_ops *
 254 hw_perf_counter_init(struct perf_counter *counter);
 255
 256 extern void perf_counter_task_sched_in(struct task_struct *task, int cpu);
 257 extern void perf_counter_task_sched_out(struct task_struct *task, int cpu);
 258 extern void perf_counter_task_tick(struct task_struct *task, int cpu);
 259 extern void perf_counter_init_task(struct task_struct *child);
 260 extern void perf_counter_exit_task(struct task_struct *child);
 261 extern void perf_counter_notify(struct pt_regs *regs);
 262 extern void perf_counter_print_debug(void);
 263 extern void perf_counter_unthrottle(void);
 264 extern u64 hw_perf_save_disable(void);
 265 extern void hw_perf_restore(u64 ctrl);
 266 extern int perf_counter_task_disable(void);
 267 extern int perf_counter_task_enable(void);
 268 extern int hw_perf_group_sched_in(struct perf_counter *group_leader,
 269                struct perf_cpu_context *cpuctx,
 270                struct perf_counter_context *ctx, int cpu);
 271
 272 /*
 273  * Return 1 for a software counter, 0 for a hardware counter
 274  */
 275 static inline int is_software_counter(struct perf_counter *counter)
 276 {
 277         return !counter->hw_event.raw && counter->hw_event.type < 0;
 278 }
 279
 280 #else
 281 static inline void
 282 perf_counter_task_sched_in(struct task_struct *task, int cpu)           { }
 283 static inline void
 284 perf_counter_task_sched_out(struct task_struct *task, int cpu)          { }
 285 static inline void
 286 perf_counter_task_tick(struct task_struct *task, int cpu)               { }
 287 static inline void perf_counter_init_task(struct task_struct *child)    { }
 288 static inline void perf_counter_exit_task(struct task_struct *child)    { }
 289 static inline void perf_counter_notify(struct pt_regs *regs)            { }
 290 static inline void perf_counter_print_debug(void)                       { }
 291 static inline void perf_counter_unthrottle(void)                        { }
 292 static inline void hw_perf_restore(u64 ctrl)                    { }
 293 static inline u64 hw_perf_save_disable(void)                  { return 0; }
 294 static inline int perf_counter_task_disable(void)       { return -EINVAL; }
 295 static inline int perf_counter_task_enable(void)        { return -EINVAL; }
 296 #endif
 297
 298 #endif /* __KERNEL__ */
 299 #endif /* _LINUX_PERF_COUNTER_H */