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                                 inherit      :  1, /* children inherit it */
  82                                 __reserved_1 : 28;
  83
  84         u64                     __reserved_2;
  85 };
  86
  87 /*
  88  * Kernel-internal data types:
  89  */
  90
  91 /**
  92  * struct hw_perf_counter - performance counter hardware details:
  93  */
  94 struct hw_perf_counter {
  95 #ifdef CONFIG_PERF_COUNTERS
  96         u64                             config;
  97         unsigned long                   config_base;
  98         unsigned long                   counter_base;
  99         int                             nmi;
 100         unsigned int                    idx;
 101         atomic64_t                      prev_count;
 102         u64                             irq_period;
 103         atomic64_t                      period_left;
 104 #endif
 105 };
 106
 107 /*
 108  * Hardcoded buffer length limit for now, for IRQ-fed events:
 109  */
 110 #define PERF_DATA_BUFLEN                2048
 111
 112 /**
 113  * struct perf_data - performance counter IRQ data sampling ...
 114  */
 115 struct perf_data {
 116         int                             len;
 117         int                             rd_idx;
 118         int                             overrun;
 119         u8                              data[PERF_DATA_BUFLEN];
 120 };
 121
 122 struct perf_counter;
 123
 124 /**
 125  * struct hw_perf_counter_ops - performance counter hw ops
 126  */
 127 struct hw_perf_counter_ops {
 128         void (*hw_perf_counter_enable)  (struct perf_counter *counter);
 129         void (*hw_perf_counter_disable) (struct perf_counter *counter);
 130         void (*hw_perf_counter_read)    (struct perf_counter *counter);
 131 };
 132
 133 /**
 134  * enum perf_counter_active_state - the states of a counter
 135  */
 136 enum perf_counter_active_state {
 137         PERF_COUNTER_STATE_OFF          = -1,
 138         PERF_COUNTER_STATE_INACTIVE     =  0,
 139         PERF_COUNTER_STATE_ACTIVE       =  1,
 140 };
 141
 142 struct file;
 143
 144 /**
 145  * struct perf_counter - performance counter kernel representation:
 146  */
 147 struct perf_counter {
 148 #ifdef CONFIG_PERF_COUNTERS
 149         struct list_head                list_entry;
 150         struct list_head                sibling_list;
 151         struct perf_counter             *group_leader;
 152         const struct hw_perf_counter_ops *hw_ops;
 153
 154         enum perf_counter_active_state  state;
 155         atomic64_t                      count;
 156
 157         struct perf_counter_hw_event    hw_event;
 158         struct hw_perf_counter          hw;
 159
 160         struct perf_counter_context     *ctx;
 161         struct task_struct              *task;
 162         struct file                     *filp;
 163
 164         unsigned int                    nr_inherited;
 165         struct perf_counter             *parent;
 166         /*
 167          * Protect attach/detach:
 168          */
 169         struct mutex                    mutex;
 170
 171         int                             oncpu;
 172         int                             cpu;
 173
 174         /* read() / irq related data */
 175         wait_queue_head_t               waitq;
 176         /* optional: for NMIs */
 177         int                             wakeup_pending;
 178         struct perf_data                *irqdata;
 179         struct perf_data                *usrdata;
 180         struct perf_data                data[2];
 181 #endif
 182 };
 183
 184 /**
 185  * struct perf_counter_context - counter context structure
 186  *
 187  * Used as a container for task counters and CPU counters as well:
 188  */
 189 struct perf_counter_context {
 190 #ifdef CONFIG_PERF_COUNTERS
 191         /*
 192          * Protect the list of counters:
 193          */
 194         spinlock_t              lock;
 195
 196         struct list_head        counter_list;
 197         int                     nr_counters;
 198         int                     nr_active;
 199         struct task_struct      *task;
 200 #endif
 201 };
 202
 203 /**
 204  * struct perf_counter_cpu_context - per cpu counter context structure
 205  */
 206 struct perf_cpu_context {
 207         struct perf_counter_context     ctx;
 208         struct perf_counter_context     *task_ctx;
 209         int                             active_oncpu;
 210         int                             max_pertask;
 211 };
 212
 213 /*
 214  * Set by architecture code:
 215  */
 216 extern int perf_max_counters;
 217
 218 #ifdef CONFIG_PERF_COUNTERS
 219 extern void
 220 perf_counter_show(struct perf_counter *counter, char *str, int trace);
 221 extern const struct hw_perf_counter_ops *
 222 hw_perf_counter_init(struct perf_counter *counter);
 223
 224 extern void perf_counter_task_sched_in(struct task_struct *task, int cpu);
 225 extern void perf_counter_task_sched_out(struct task_struct *task, int cpu);
 226 extern void perf_counter_task_tick(struct task_struct *task, int cpu);
 227 extern void perf_counter_init_task(struct task_struct *child);
 228 extern void perf_counter_exit_task(struct task_struct *child);
 229 extern void perf_counter_notify(struct pt_regs *regs);
 230 extern void perf_counter_print_debug(void);
 231 extern u64 hw_perf_save_disable(void);
 232 extern void hw_perf_restore(u64 ctrl);
 233 extern int perf_counter_task_disable(void);
 234 extern int perf_counter_task_enable(void);
 235
 236 #else
 237 static inline void
 238 perf_counter_show(struct perf_counter *counter, char *str, int trace)   { }
 239 static inline void
 240 perf_counter_task_sched_in(struct task_struct *task, int cpu)           { }
 241 static inline void
 242 perf_counter_task_sched_out(struct task_struct *task, int cpu)          { }
 243 static inline void
 244 perf_counter_task_tick(struct task_struct *task, int cpu)               { }
 245 static inline void perf_counter_init_task(struct task_struct *child)    { }
 246 static inline void perf_counter_exit_task(struct task_struct *child)    { }
 247 static inline void perf_counter_notify(struct pt_regs *regs)            { }
 248 static inline void perf_counter_print_debug(void)                       { }
 249 static inline void hw_perf_restore(u64 ctrl)                    { }
 250 static inline u64 hw_perf_save_disable(void)                  { return 0; }
 251 static inline int perf_counter_task_disable(void)       { return -EINVAL; }
 252 static inline int perf_counter_task_enable(void)        { return -EINVAL; }
 253 #endif
 254
 255 #endif /* _LINUX_PERF_COUNTER_H */