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         PERF_COUNT_PAGE_FAULTS          = -3,
  54         PERF_COUNT_CONTEXT_SWITCHES     = -4,
  55 };
  56
  57 /*
  58  * IRQ-notification data record type:
  59  */
  60 enum perf_counter_record_type {
  61         PERF_RECORD_SIMPLE              =  0,
  62         PERF_RECORD_IRQ                 =  1,
  63         PERF_RECORD_GROUP               =  2,
  64 };
  65
  66 /*
  67  * Hardware event to monitor via a performance monitoring counter:
  68  */
  69 struct perf_counter_hw_event {
  70         u64                     type;
  71
  72         u64                     irq_period;
  73         u32                     record_type;
  74
  75         u32                     disabled     :  1, /* off by default */
  76                                 nmi          :  1, /* NMI sampling   */
  77                                 raw          :  1, /* raw event type */
  78                                 __reserved_1 : 29;
  79
  80         u64                     __reserved_2;
  81 };
  82
  83 /*
  84  * Kernel-internal data types:
  85  */
  86
  87 /**
  88  * struct hw_perf_counter - performance counter hardware details:
  89  */
  90 struct hw_perf_counter {
  91         u64                             config;
  92         unsigned long                   config_base;
  93         unsigned long                   counter_base;
  94         int                             nmi;
  95         unsigned int                    idx;
  96         u64                             prev_count;
  97         u64                             irq_period;
  98         s32                             next_count;
  99 };
 100
 101 /*
 102  * Hardcoded buffer length limit for now, for IRQ-fed events:
 103  */
 104 #define PERF_DATA_BUFLEN                2048
 105
 106 /**
 107  * struct perf_data - performance counter IRQ data sampling ...
 108  */
 109 struct perf_data {
 110         int                             len;
 111         int                             rd_idx;
 112         int                             overrun;
 113         u8                              data[PERF_DATA_BUFLEN];
 114 };
 115
 116 struct perf_counter;
 117
 118 /**
 119  * struct hw_perf_counter_ops - performance counter hw ops
 120  */
 121 struct hw_perf_counter_ops {
 122         void (*hw_perf_counter_enable)  (struct perf_counter *counter);
 123         void (*hw_perf_counter_disable) (struct perf_counter *counter);
 124         void (*hw_perf_counter_read)    (struct perf_counter *counter);
 125 };
 126
 127 /**
 128  * struct perf_counter - performance counter kernel representation:
 129  */
 130 struct perf_counter {
 131         struct list_head                list_entry;
 132         struct list_head                sibling_list;
 133         struct perf_counter             *group_leader;
 134         struct hw_perf_counter_ops      *hw_ops;
 135
 136         int                             active;
 137 #if BITS_PER_LONG == 64
 138         atomic64_t                      count;
 139 #else
 140         atomic_t                        count32[2];
 141 #endif
 142         struct perf_counter_hw_event    hw_event;
 143         struct hw_perf_counter          hw;
 144
 145         struct perf_counter_context     *ctx;
 146         struct task_struct              *task;
 147
 148         /*
 149          * Protect attach/detach:
 150          */
 151         struct mutex                    mutex;
 152
 153         int                             oncpu;
 154         int                             cpu;
 155
 156         /* read() / irq related data */
 157         wait_queue_head_t               waitq;
 158         /* optional: for NMIs */
 159         int                             wakeup_pending;
 160         struct perf_data                *irqdata;
 161         struct perf_data                *usrdata;
 162         struct perf_data                data[2];
 163 };
 164
 165 /**
 166  * struct perf_counter_context - counter context structure
 167  *
 168  * Used as a container for task counters and CPU counters as well:
 169  */
 170 struct perf_counter_context {
 171 #ifdef CONFIG_PERF_COUNTERS
 172         /*
 173          * Protect the list of counters:
 174          */
 175         spinlock_t              lock;
 176
 177         struct list_head        counter_list;
 178         int                     nr_counters;
 179         int                     nr_active;
 180         struct task_struct      *task;
 181 #endif
 182 };
 183
 184 /**
 185  * struct perf_counter_cpu_context - per cpu counter context structure
 186  */
 187 struct perf_cpu_context {
 188         struct perf_counter_context     ctx;
 189         struct perf_counter_context     *task_ctx;
 190         int                             active_oncpu;
 191         int                             max_pertask;
 192 };
 193
 194 /*
 195  * Set by architecture code:
 196  */
 197 extern int perf_max_counters;
 198
 199 #ifdef CONFIG_PERF_COUNTERS
 200 extern struct hw_perf_counter_ops *
 201 hw_perf_counter_init(struct perf_counter *counter);
 202
 203 extern void perf_counter_task_sched_in(struct task_struct *task, int cpu);
 204 extern void perf_counter_task_sched_out(struct task_struct *task, int cpu);
 205 extern void perf_counter_task_tick(struct task_struct *task, int cpu);
 206 extern void perf_counter_init_task(struct task_struct *task);
 207 extern void perf_counter_notify(struct pt_regs *regs);
 208 extern void perf_counter_print_debug(void);
 209 extern void hw_perf_restore_ctrl(u64 ctrl);
 210 extern u64 hw_perf_disable_all(void);
 211 #else
 212 static inline void
 213 perf_counter_task_sched_in(struct task_struct *task, int cpu)           { }
 214 static inline void
 215 perf_counter_task_sched_out(struct task_struct *task, int cpu)          { }
 216 static inline void
 217 perf_counter_task_tick(struct task_struct *task, int cpu)               { }
 218 static inline void perf_counter_init_task(struct task_struct *task)     { }
 219 static inline void perf_counter_notify(struct pt_regs *regs)            { }
 220 static inline void perf_counter_print_debug(void)                       { }
 221 static inline void hw_perf_restore_ctrl(u64 ctrl)                       { }
 222 static inline u64 hw_perf_disable_all(void)             { return 0; }
 223 #endif
 224
 225 #endif /* _LINUX_PERF_COUNTER_H */