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 <asm/atomic.h>
 118
 119 struct task_struct;
 120
 121 /**
 122  * struct hw_perf_counter - performance counter hardware details:
 123  */
 124 struct hw_perf_counter {
 125 #ifdef CONFIG_PERF_COUNTERS
 126         u64                             config;
 127         unsigned long                   config_base;
 128         unsigned long                   counter_base;
 129         int                             nmi;
 130         unsigned int                    idx;
 131         atomic64_t                      count; /* software */
 132         atomic64_t                      prev_count;
 133         u64                             irq_period;
 134         atomic64_t                      period_left;
 135 #endif
 136 };
 137
 138 /*
 139  * Hardcoded buffer length limit for now, for IRQ-fed events:
 140  */
 141 #define PERF_DATA_BUFLEN                2048
 142
 143 /**
 144  * struct perf_data - performance counter IRQ data sampling ...
 145  */
 146 struct perf_data {
 147         int                             len;
 148         int                             rd_idx;
 149         int                             overrun;
 150         u8                              data[PERF_DATA_BUFLEN];
 151 };
 152
 153 struct perf_counter;
 154
 155 /**
 156  * struct hw_perf_counter_ops - performance counter hw ops
 157  */
 158 struct hw_perf_counter_ops {
 159         int (*enable)                   (struct perf_counter *counter);
 160         void (*disable)                 (struct perf_counter *counter);
 161         void (*read)                    (struct perf_counter *counter);
 162 };
 163
 164 /**
 165  * enum perf_counter_active_state - the states of a counter
 166  */
 167 enum perf_counter_active_state {
 168         PERF_COUNTER_STATE_ERROR        = -2,
 169         PERF_COUNTER_STATE_OFF          = -1,
 170         PERF_COUNTER_STATE_INACTIVE     =  0,
 171         PERF_COUNTER_STATE_ACTIVE       =  1,
 172 };
 173
 174 struct file;
 175
 176 /**
 177  * struct perf_counter - performance counter kernel representation:
 178  */
 179 struct perf_counter {
 180 #ifdef CONFIG_PERF_COUNTERS
 181         struct list_head                list_entry;
 182         struct list_head                sibling_list;
 183         struct perf_counter             *group_leader;
 184         const struct hw_perf_counter_ops *hw_ops;
 185
 186         enum perf_counter_active_state  state;
 187         enum perf_counter_active_state  prev_state;
 188         atomic64_t                      count;
 189
 190         struct perf_counter_hw_event    hw_event;
 191         struct hw_perf_counter          hw;
 192
 193         struct perf_counter_context     *ctx;
 194         struct task_struct              *task;
 195         struct file                     *filp;
 196
 197         struct perf_counter             *parent;
 198         struct list_head                child_list;
 199
 200         /*
 201          * Protect attach/detach and child_list:
 202          */
 203         struct mutex                    mutex;
 204
 205         int                             oncpu;
 206         int                             cpu;
 207
 208         /* read() / irq related data */
 209         wait_queue_head_t               waitq;
 210         /* optional: for NMIs */
 211         int                             wakeup_pending;
 212         struct perf_data                *irqdata;
 213         struct perf_data                *usrdata;
 214         struct perf_data                data[2];
 215 #endif
 216 };
 217
 218 /**
 219  * struct perf_counter_context - counter context structure
 220  *
 221  * Used as a container for task counters and CPU counters as well:
 222  */
 223 struct perf_counter_context {
 224 #ifdef CONFIG_PERF_COUNTERS
 225         /*
 226          * Protect the states of the counters in the list,
 227          * nr_active, and the list:
 228          */
 229         spinlock_t              lock;
 230         /*
 231          * Protect the list of counters.  Locking either mutex or lock
 232          * is sufficient to ensure the list doesn't change; to change
 233          * the list you need to lock both the mutex and the spinlock.
 234          */
 235         struct mutex            mutex;
 236
 237         struct list_head        counter_list;
 238         int                     nr_counters;
 239         int                     nr_active;
 240         int                     is_active;
 241         struct task_struct      *task;
 242 #endif
 243 };
 244
 245 /**
 246  * struct perf_counter_cpu_context - per cpu counter context structure
 247  */
 248 struct perf_cpu_context {
 249         struct perf_counter_context     ctx;
 250         struct perf_counter_context     *task_ctx;
 251         int                             active_oncpu;
 252         int                             max_pertask;
 253         int                             exclusive;
 254 };
 255
 256 /*
 257  * Set by architecture code:
 258  */
 259 extern int perf_max_counters;
 260
 261 #ifdef CONFIG_PERF_COUNTERS
 262 extern const struct hw_perf_counter_ops *
 263 hw_perf_counter_init(struct perf_counter *counter);
 264
 265 extern void perf_counter_task_sched_in(struct task_struct *task, int cpu);
 266 extern void perf_counter_task_sched_out(struct task_struct *task, int cpu);
 267 extern void perf_counter_task_tick(struct task_struct *task, int cpu);
 268 extern void perf_counter_init_task(struct task_struct *child);
 269 extern void perf_counter_exit_task(struct task_struct *child);
 270 extern void perf_counter_notify(struct pt_regs *regs);
 271 extern void perf_counter_print_debug(void);
 272 extern void perf_counter_unthrottle(void);
 273 extern u64 hw_perf_save_disable(void);
 274 extern void hw_perf_restore(u64 ctrl);
 275 extern int perf_counter_task_disable(void);
 276 extern int perf_counter_task_enable(void);
 277 extern int hw_perf_group_sched_in(struct perf_counter *group_leader,
 278                struct perf_cpu_context *cpuctx,
 279                struct perf_counter_context *ctx, int cpu);
 280
 281 /*
 282  * Return 1 for a software counter, 0 for a hardware counter
 283  */
 284 static inline int is_software_counter(struct perf_counter *counter)
 285 {
 286         return !counter->hw_event.raw && counter->hw_event.type < 0;
 287 }
 288
 289 extern void perf_swcounter_event(enum hw_event_types, u64, int, struct pt_regs *);
 290
 291 #else
 292 static inline void
 293 perf_counter_task_sched_in(struct task_struct *task, int cpu)           { }
 294 static inline void
 295 perf_counter_task_sched_out(struct task_struct *task, int cpu)          { }
 296 static inline void
 297 perf_counter_task_tick(struct task_struct *task, int cpu)               { }
 298 static inline void perf_counter_init_task(struct task_struct *child)    { }
 299 static inline void perf_counter_exit_task(struct task_struct *child)    { }
 300 static inline void perf_counter_notify(struct pt_regs *regs)            { }
 301 static inline void perf_counter_print_debug(void)                       { }
 302 static inline void perf_counter_unthrottle(void)                        { }
 303 static inline void hw_perf_restore(u64 ctrl)                            { }
 304 static inline u64 hw_perf_save_disable(void)                  { return 0; }
 305 static inline int perf_counter_task_disable(void)       { return -EINVAL; }
 306 static inline int perf_counter_task_enable(void)        { return -EINVAL; }
 307
 308 static inline void perf_swcounter_event(enum hw_event_types event, u64 nr,
 309                                         int nmi, struct pt_regs *regs)  { }
 310 #endif
 311
 312 #endif /* __KERNEL__ */
 313 #endif /* _LINUX_PERF_COUNTER_H */