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
  18 #include <linux/list.h>
  19 #include <linux/mutex.h>
  20 #include <linux/rculist.h>
  21 #include <linux/rcupdate.h>
  22 #include <linux/spinlock.h>
  23
  24 struct task_struct;
  25
  26 /*
  27  * User-space ABI bits:
  28  */
  29
  30 /*
  31  * Generalized performance counter event types, used by the hw_event.type
  32  * parameter of the sys_perf_counter_open() syscall:
  33  */
  34 enum hw_event_types {
  35         /*
  36          * Common hardware events, generalized by the kernel:
  37          */
  38         PERF_COUNT_CYCLES               =  0,
  39         PERF_COUNT_INSTRUCTIONS         =  1,
  40         PERF_COUNT_CACHE_REFERENCES     =  2,
  41         PERF_COUNT_CACHE_MISSES         =  3,
  42         PERF_COUNT_BRANCH_INSTRUCTIONS  =  4,
  43         PERF_COUNT_BRANCH_MISSES        =  5,
  44
  45         /*
  46          * Special "software" counters provided by the kernel, even if
  47          * the hardware does not support performance counters. These
  48          * counters measure various physical and sw events of the
  49          * kernel (and allow the profiling of them as well):
  50          */
  51         PERF_COUNT_CPU_CLOCK            = -1,
  52         PERF_COUNT_TASK_CLOCK           = -2,
  53         /*
  54          * Future software events:
  55          */
  56         /* PERF_COUNT_PAGE_FAULTS       = -3,
  57            PERF_COUNT_CONTEXT_SWITCHES  = -4, */
  58 };
  59
  60 /*
  61  * IRQ-notification data record type:
  62  */
  63 enum perf_counter_record_type {
  64         PERF_RECORD_SIMPLE              =  0,
  65         PERF_RECORD_IRQ                 =  1,
  66         PERF_RECORD_GROUP               =  2,
  67 };
  68
  69 /*
  70  * Hardware event to monitor via a performance monitoring counter:
  71  */
  72 struct perf_counter_hw_event {
  73         s64                     type;
  74
  75         u64                     irq_period;
  76         u32                     record_type;
  77
  78         u32                     disabled     :  1, /* off by default */
  79                                 nmi          :  1, /* NMI sampling   */
  80                                 raw          :  1, /* raw event type */
  81                                 __reserved_1 : 29;
  82
  83         u64                     __reserved_2;
  84 };
  85
  86 /*
  87  * Kernel-internal data types:
  88  */
  89
  90 /**
  91  * struct hw_perf_counter - performance counter hardware details:
  92  */
  93 struct hw_perf_counter {
  94         u64                             config;
  95         unsigned long                   config_base;
  96         unsigned long                   counter_base;
  97         int                             nmi;
  98         unsigned int                    idx;
  99         u64                             prev_count;
 100         u64                             irq_period;
 101         s32                             next_count;
 102 };
 103
 104 /*
 105  * Hardcoded buffer length limit for now, for IRQ-fed events:
 106  */
 107 #define PERF_DATA_BUFLEN                2048
 108
 109 /**
 110  * struct perf_data - performance counter IRQ data sampling ...
 111  */
 112 struct perf_data {
 113         int                             len;
 114         int                             rd_idx;
 115         int                             overrun;
 116         u8                              data[PERF_DATA_BUFLEN];
 117 };
 118
 119 struct perf_counter;
 120
 121 /**
 122  * struct hw_perf_counter_ops - performance counter hw ops
 123  */
 124 struct hw_perf_counter_ops {
 125         void (*hw_perf_counter_enable)  (struct perf_counter *counter);
 126         void (*hw_perf_counter_disable) (struct perf_counter *counter);
 127         void (*hw_perf_counter_read)    (struct perf_counter *counter);
 128 };
 129
 130 /**
 131  * struct perf_counter - performance counter kernel representation:
 132  */
 133 struct perf_counter {
 134         struct list_head                list_entry;
 135         struct list_head                sibling_list;
 136         struct perf_counter             *group_leader;
 137         const struct hw_perf_counter_ops *hw_ops;
 138
 139         int                             active;
 140 #if BITS_PER_LONG == 64
 141         atomic64_t                      count;
 142 #else
 143         atomic_t                        count32[2];
 144 #endif
 145         struct perf_counter_hw_event    hw_event;
 146         struct hw_perf_counter          hw;
 147
 148         struct perf_counter_context     *ctx;
 149         struct task_struct              *task;
 150
 151         /*
 152          * Protect attach/detach:
 153          */
 154         struct mutex                    mutex;
 155
 156         int                             oncpu;
 157         int                             cpu;
 158
 159         /* read() / irq related data */
 160         wait_queue_head_t               waitq;
 161         /* optional: for NMIs */
 162         int                             wakeup_pending;
 163         struct perf_data                *irqdata;
 164         struct perf_data                *usrdata;
 165         struct perf_data                data[2];
 166 };
 167
 168 /**
 169  * struct perf_counter_context - counter context structure
 170  *
 171  * Used as a container for task counters and CPU counters as well:
 172  */
 173 struct perf_counter_context {
 174 #ifdef CONFIG_PERF_COUNTERS
 175         /*
 176          * Protect the list of counters:
 177          */
 178         spinlock_t              lock;
 179
 180         struct list_head        counter_list;
 181         int                     nr_counters;
 182         int                     nr_active;
 183         struct task_struct      *task;
 184 #endif
 185 };
 186
 187 /**
 188  * struct perf_counter_cpu_context - per cpu counter context structure
 189  */
 190 struct perf_cpu_context {
 191         struct perf_counter_context     ctx;
 192         struct perf_counter_context     *task_ctx;
 193         int                             active_oncpu;
 194         int                             max_pertask;
 195 };
 196
 197 /*
 198  * Set by architecture code:
 199  */
 200 extern int perf_max_counters;
 201
 202 #ifdef CONFIG_PERF_COUNTERS
 203 extern const struct hw_perf_counter_ops *
 204 hw_perf_counter_init(struct perf_counter *counter);
 205
 206 extern void perf_counter_task_sched_in(struct task_struct *task, int cpu);
 207 extern void perf_counter_task_sched_out(struct task_struct *task, int cpu);
 208 extern void perf_counter_task_tick(struct task_struct *task, int cpu);
 209 extern void perf_counter_init_task(struct task_struct *task);
 210 extern void perf_counter_notify(struct pt_regs *regs);
 211 extern void perf_counter_print_debug(void);
 212 extern u64 hw_perf_save_disable(void);
 213 extern void hw_perf_restore(u64 ctrl);
 214 extern void atomic64_counter_set(struct perf_counter *counter, u64 val64);
 215 extern u64 atomic64_counter_read(struct perf_counter *counter);
 216
 217 #else
 218 static inline void
 219 perf_counter_task_sched_in(struct task_struct *task, int cpu)           { }
 220 static inline void
 221 perf_counter_task_sched_out(struct task_struct *task, int cpu)          { }
 222 static inline void
 223 perf_counter_task_tick(struct task_struct *task, int cpu)               { }
 224 static inline void perf_counter_init_task(struct task_struct *task)     { }
 225 static inline void perf_counter_notify(struct pt_regs *regs)            { }
 226 static inline void perf_counter_print_debug(void)                       { }
 227 static inline void hw_perf_restore(u64 ctrl)                    { }
 228 static inline u64 hw_perf_save_disable(void)                  { return 0; }
 229 #endif
 230
 231 #endif /* _LINUX_PERF_COUNTER_H */