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 <asm/atomic.h>
  17 #include <asm/ioctl.h>
  18
  19 #ifdef CONFIG_PERF_COUNTERS
  20 # include <asm/perf_counter.h>
  21 #endif
  22
  23 #include <linux/list.h>
  24 #include <linux/mutex.h>
  25 #include <linux/rculist.h>
  26 #include <linux/rcupdate.h>
  27 #include <linux/spinlock.h>
  28
  29 struct task_struct;
  30
  31 /*
  32  * User-space ABI bits:
  33  */
  34
  35 /*
  36  * Generalized performance counter event types, used by the hw_event.type
  37  * parameter of the sys_perf_counter_open() syscall:
  38  */
  39 enum hw_event_types {
  40         /*
  41          * Common hardware events, generalized by the kernel:
  42          */
  43         PERF_COUNT_CPU_CYCLES           =  0,
  44         PERF_COUNT_INSTRUCTIONS         =  1,
  45         PERF_COUNT_CACHE_REFERENCES     =  2,
  46         PERF_COUNT_CACHE_MISSES         =  3,
  47         PERF_COUNT_BRANCH_INSTRUCTIONS  =  4,
  48         PERF_COUNT_BRANCH_MISSES        =  5,
  49         PERF_COUNT_BUS_CYCLES           =  6,
  50
  51         PERF_HW_EVENTS_MAX              =  7,
  52
  53         /*
  54          * Special "software" counters provided by the kernel, even if
  55          * the hardware does not support performance counters. These
  56          * counters measure various physical and sw events of the
  57          * kernel (and allow the profiling of them as well):
  58          */
  59         PERF_COUNT_CPU_CLOCK            = -1,
  60         PERF_COUNT_TASK_CLOCK           = -2,
  61         PERF_COUNT_PAGE_FAULTS          = -3,
  62         PERF_COUNT_CONTEXT_SWITCHES     = -4,
  63         PERF_COUNT_CPU_MIGRATIONS       = -5,
  64
  65         PERF_SW_EVENTS_MIN              = -6,
  66 };
  67
  68 /*
  69  * IRQ-notification data record type:
  70  */
  71 enum perf_counter_record_type {
  72         PERF_RECORD_SIMPLE              =  0,
  73         PERF_RECORD_IRQ                 =  1,
  74         PERF_RECORD_GROUP               =  2,
  75 };
  76
  77 /*
  78  * Hardware event to monitor via a performance monitoring counter:
  79  */
  80 struct perf_counter_hw_event {
  81         s64                     type;
  82
  83         u64                     irq_period;
  84         u32                     record_type;
  85
  86         u32                     disabled     :  1, /* off by default      */
  87                                 nmi          :  1, /* NMI sampling        */
  88                                 raw          :  1, /* raw event type      */
  89                                 inherit      :  1, /* children inherit it */
  90                                 pinned       :  1, /* must always be on PMU */
  91                                 exclusive    :  1, /* only counter on PMU */
  92
  93                                 __reserved_1 : 26;
  94
  95         u64                     __reserved_2;
  96 };
  97
  98 /*
  99  * Ioctls that can be done on a perf counter fd:
 100  */
 101 #define PERF_COUNTER_IOC_ENABLE         _IO('$', 0)
 102 #define PERF_COUNTER_IOC_DISABLE        _IO('$', 1)
 103
 104 /*
 105  * Kernel-internal data types:
 106  */
 107
 108 /**
 109  * struct hw_perf_counter - performance counter hardware details:
 110  */
 111 struct hw_perf_counter {
 112 #ifdef CONFIG_PERF_COUNTERS
 113         u64                             config;
 114         unsigned long                   config_base;
 115         unsigned long                   counter_base;
 116         int                             nmi;
 117         unsigned int                    idx;
 118         atomic64_t                      prev_count;
 119         u64                             irq_period;
 120         atomic64_t                      period_left;
 121 #endif
 122 };
 123
 124 /*
 125  * Hardcoded buffer length limit for now, for IRQ-fed events:
 126  */
 127 #define PERF_DATA_BUFLEN                2048
 128
 129 /**
 130  * struct perf_data - performance counter IRQ data sampling ...
 131  */
 132 struct perf_data {
 133         int                             len;
 134         int                             rd_idx;
 135         int                             overrun;
 136         u8                              data[PERF_DATA_BUFLEN];
 137 };
 138
 139 struct perf_counter;
 140
 141 /**
 142  * struct hw_perf_counter_ops - performance counter hw ops
 143  */
 144 struct hw_perf_counter_ops {
 145         int (*enable)                   (struct perf_counter *counter);
 146         void (*disable)                 (struct perf_counter *counter);
 147         void (*read)                    (struct perf_counter *counter);
 148 };
 149
 150 /**
 151  * enum perf_counter_active_state - the states of a counter
 152  */
 153 enum perf_counter_active_state {
 154         PERF_COUNTER_STATE_ERROR        = -2,
 155         PERF_COUNTER_STATE_OFF          = -1,
 156         PERF_COUNTER_STATE_INACTIVE     =  0,
 157         PERF_COUNTER_STATE_ACTIVE       =  1,
 158 };
 159
 160 struct file;
 161
 162 /**
 163  * struct perf_counter - performance counter kernel representation:
 164  */
 165 struct perf_counter {
 166 #ifdef CONFIG_PERF_COUNTERS
 167         struct list_head                list_entry;
 168         struct list_head                sibling_list;
 169         struct perf_counter             *group_leader;
 170         const struct hw_perf_counter_ops *hw_ops;
 171
 172         enum perf_counter_active_state  state;
 173         atomic64_t                      count;
 174
 175         struct perf_counter_hw_event    hw_event;
 176         struct hw_perf_counter          hw;
 177
 178         struct perf_counter_context     *ctx;
 179         struct task_struct              *task;
 180         struct file                     *filp;
 181
 182         struct perf_counter             *parent;
 183         struct list_head                child_list;
 184
 185         /*
 186          * Protect attach/detach and child_list:
 187          */
 188         struct mutex                    mutex;
 189
 190         int                             oncpu;
 191         int                             cpu;
 192
 193         /* read() / irq related data */
 194         wait_queue_head_t               waitq;
 195         /* optional: for NMIs */
 196         int                             wakeup_pending;
 197         struct perf_data                *irqdata;
 198         struct perf_data                *usrdata;
 199         struct perf_data                data[2];
 200 #endif
 201 };
 202
 203 /**
 204  * struct perf_counter_context - counter context structure
 205  *
 206  * Used as a container for task counters and CPU counters as well:
 207  */
 208 struct perf_counter_context {
 209 #ifdef CONFIG_PERF_COUNTERS
 210         /*
 211          * Protect the states of the counters in the list,
 212          * nr_active, and the list:
 213          */
 214         spinlock_t              lock;
 215         /*
 216          * Protect the list of counters.  Locking either mutex or lock
 217          * is sufficient to ensure the list doesn't change; to change
 218          * the list you need to lock both the mutex and the spinlock.
 219          */
 220         struct mutex            mutex;
 221
 222         struct list_head        counter_list;
 223         int                     nr_counters;
 224         int                     nr_active;
 225         int                     is_active;
 226         struct task_struct      *task;
 227 #endif
 228 };
 229
 230 /**
 231  * struct perf_counter_cpu_context - per cpu counter context structure
 232  */
 233 struct perf_cpu_context {
 234         struct perf_counter_context     ctx;
 235         struct perf_counter_context     *task_ctx;
 236         int                             active_oncpu;
 237         int                             max_pertask;
 238         int                             exclusive;
 239 };
 240
 241 /*
 242  * Set by architecture code:
 243  */
 244 extern int perf_max_counters;
 245
 246 #ifdef CONFIG_PERF_COUNTERS
 247 extern const struct hw_perf_counter_ops *
 248 hw_perf_counter_init(struct perf_counter *counter);
 249
 250 extern void perf_counter_task_sched_in(struct task_struct *task, int cpu);
 251 extern void perf_counter_task_sched_out(struct task_struct *task, int cpu);
 252 extern void perf_counter_task_tick(struct task_struct *task, int cpu);
 253 extern void perf_counter_init_task(struct task_struct *child);
 254 extern void perf_counter_exit_task(struct task_struct *child);
 255 extern void perf_counter_notify(struct pt_regs *regs);
 256 extern void perf_counter_print_debug(void);
 257 extern void perf_counter_unthrottle(void);
 258 extern u64 hw_perf_save_disable(void);
 259 extern void hw_perf_restore(u64 ctrl);
 260 extern int perf_counter_task_disable(void);
 261 extern int perf_counter_task_enable(void);
 262 extern int hw_perf_group_sched_in(struct perf_counter *group_leader,
 263                struct perf_cpu_context *cpuctx,
 264                struct perf_counter_context *ctx, int cpu);
 265
 266 /*
 267  * Return 1 for a software counter, 0 for a hardware counter
 268  */
 269 static inline int is_software_counter(struct perf_counter *counter)
 270 {
 271         return !counter->hw_event.raw && counter->hw_event.type < 0;
 272 }
 273
 274 #else
 275 static inline void
 276 perf_counter_task_sched_in(struct task_struct *task, int cpu)           { }
 277 static inline void
 278 perf_counter_task_sched_out(struct task_struct *task, int cpu)          { }
 279 static inline void
 280 perf_counter_task_tick(struct task_struct *task, int cpu)               { }
 281 static inline void perf_counter_init_task(struct task_struct *child)    { }
 282 static inline void perf_counter_exit_task(struct task_struct *child)    { }
 283 static inline void perf_counter_notify(struct pt_regs *regs)            { }
 284 static inline void perf_counter_print_debug(void)                       { }
 285 static inline void perf_counter_unthrottle(void)                        { }
 286 static inline void hw_perf_restore(u64 ctrl)                    { }
 287 static inline u64 hw_perf_save_disable(void)                  { return 0; }
 288 static inline int perf_counter_task_disable(void)       { return -EINVAL; }
 289 static inline int perf_counter_task_enable(void)        { return -EINVAL; }
 290 #endif
 291
 292 #endif /* _LINUX_PERF_COUNTER_H */