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         PERF_HW_EVENTS_MAX              =  6,
  46
  47         /*
  48          * Special "software" counters provided by the kernel, even if
  49          * the hardware does not support performance counters. These
  50          * counters measure various physical and sw events of the
  51          * kernel (and allow the profiling of them as well):
  52          */
  53         PERF_COUNT_CPU_CLOCK            = -1,
  54         PERF_COUNT_TASK_CLOCK           = -2,
  55         PERF_COUNT_PAGE_FAULTS          = -3,
  56         PERF_COUNT_CONTEXT_SWITCHES     = -4,
  57         PERF_COUNT_CPU_MIGRATIONS       = -5,
  58
  59         PERF_SW_EVENTS_MIN              = -6,
  60 };
  61
  62 /*
  63  * IRQ-notification data record type:
  64  */
  65 enum perf_counter_record_type {
  66         PERF_RECORD_SIMPLE              =  0,
  67         PERF_RECORD_IRQ                 =  1,
  68         PERF_RECORD_GROUP               =  2,
  69 };
  70
  71 /*
  72  * Hardware event to monitor via a performance monitoring counter:
  73  */
  74 struct perf_counter_hw_event {
  75         s64                     type;
  76
  77         u64                     irq_period;
  78         u32                     record_type;
  79
  80         u32                     disabled     :  1, /* off by default      */
  81                                 nmi          :  1, /* NMI sampling        */
  82                                 raw          :  1, /* raw event type      */
  83                                 inherit      :  1, /* children inherit it */
  84                                 __reserved_1 : 28;
  85
  86         u64                     __reserved_2;
  87 };
  88
  89 /*
  90  * Kernel-internal data types:
  91  */
  92
  93 /**
  94  * struct hw_perf_counter - performance counter hardware details:
  95  */
  96 struct hw_perf_counter {
  97 #ifdef CONFIG_PERF_COUNTERS
  98         u64                             config;
  99         unsigned long                   config_base;
 100         unsigned long                   counter_base;
 101         int                             nmi;
 102         unsigned int                    idx;
 103         atomic64_t                      prev_count;
 104         u64                             irq_period;
 105         atomic64_t                      period_left;
 106 #endif
 107 };
 108
 109 /*
 110  * Hardcoded buffer length limit for now, for IRQ-fed events:
 111  */
 112 #define PERF_DATA_BUFLEN                2048
 113
 114 /**
 115  * struct perf_data - performance counter IRQ data sampling ...
 116  */
 117 struct perf_data {
 118         int                             len;
 119         int                             rd_idx;
 120         int                             overrun;
 121         u8                              data[PERF_DATA_BUFLEN];
 122 };
 123
 124 struct perf_counter;
 125
 126 /**
 127  * struct hw_perf_counter_ops - performance counter hw ops
 128  */
 129 struct hw_perf_counter_ops {
 130         void (*hw_perf_counter_enable)  (struct perf_counter *counter);
 131         void (*hw_perf_counter_disable) (struct perf_counter *counter);
 132         void (*hw_perf_counter_read)    (struct perf_counter *counter);
 133 };
 134
 135 /**
 136  * enum perf_counter_active_state - the states of a counter
 137  */
 138 enum perf_counter_active_state {
 139         PERF_COUNTER_STATE_OFF          = -1,
 140         PERF_COUNTER_STATE_INACTIVE     =  0,
 141         PERF_COUNTER_STATE_ACTIVE       =  1,
 142 };
 143
 144 struct file;
 145
 146 /**
 147  * struct perf_counter - performance counter kernel representation:
 148  */
 149 struct perf_counter {
 150 #ifdef CONFIG_PERF_COUNTERS
 151         struct list_head                list_entry;
 152         struct list_head                sibling_list;
 153         struct perf_counter             *group_leader;
 154         const struct hw_perf_counter_ops *hw_ops;
 155
 156         enum perf_counter_active_state  state;
 157         atomic64_t                      count;
 158
 159         struct perf_counter_hw_event    hw_event;
 160         struct hw_perf_counter          hw;
 161
 162         struct perf_counter_context     *ctx;
 163         struct task_struct              *task;
 164         struct file                     *filp;
 165
 166         unsigned int                    nr_inherited;
 167         struct perf_counter             *parent;
 168         /*
 169          * Protect attach/detach:
 170          */
 171         struct mutex                    mutex;
 172
 173         int                             oncpu;
 174         int                             cpu;
 175
 176         /* read() / irq related data */
 177         wait_queue_head_t               waitq;
 178         /* optional: for NMIs */
 179         int                             wakeup_pending;
 180         struct perf_data                *irqdata;
 181         struct perf_data                *usrdata;
 182         struct perf_data                data[2];
 183 #endif
 184 };
 185
 186 /**
 187  * struct perf_counter_context - counter context structure
 188  *
 189  * Used as a container for task counters and CPU counters as well:
 190  */
 191 struct perf_counter_context {
 192 #ifdef CONFIG_PERF_COUNTERS
 193         /*
 194          * Protect the list of counters:
 195          */
 196         spinlock_t              lock;
 197
 198         struct list_head        counter_list;
 199         int                     nr_counters;
 200         int                     nr_active;
 201         struct task_struct      *task;
 202 #endif
 203 };
 204
 205 /**
 206  * struct perf_counter_cpu_context - per cpu counter context structure
 207  */
 208 struct perf_cpu_context {
 209         struct perf_counter_context     ctx;
 210         struct perf_counter_context     *task_ctx;
 211         int                             active_oncpu;
 212         int                             max_pertask;
 213 };
 214
 215 /*
 216  * Set by architecture code:
 217  */
 218 extern int perf_max_counters;
 219
 220 #ifdef CONFIG_PERF_COUNTERS
 221 extern void
 222 perf_counter_show(struct perf_counter *counter, char *str, int trace);
 223 extern const struct hw_perf_counter_ops *
 224 hw_perf_counter_init(struct perf_counter *counter);
 225
 226 extern void perf_counter_task_sched_in(struct task_struct *task, int cpu);
 227 extern void perf_counter_task_sched_out(struct task_struct *task, int cpu);
 228 extern void perf_counter_task_tick(struct task_struct *task, int cpu);
 229 extern void perf_counter_init_task(struct task_struct *child);
 230 extern void perf_counter_exit_task(struct task_struct *child);
 231 extern void perf_counter_notify(struct pt_regs *regs);
 232 extern void perf_counter_print_debug(void);
 233 extern u64 hw_perf_save_disable(void);
 234 extern void hw_perf_restore(u64 ctrl);
 235 extern int perf_counter_task_disable(void);
 236 extern int perf_counter_task_enable(void);
 237
 238 #else
 239 static inline void
 240 perf_counter_show(struct perf_counter *counter, char *str, int trace)   { }
 241 static inline void
 242 perf_counter_task_sched_in(struct task_struct *task, int cpu)           { }
 243 static inline void
 244 perf_counter_task_sched_out(struct task_struct *task, int cpu)          { }
 245 static inline void
 246 perf_counter_task_tick(struct task_struct *task, int cpu)               { }
 247 static inline void perf_counter_init_task(struct task_struct *child)    { }
 248 static inline void perf_counter_exit_task(struct task_struct *child)    { }
 249 static inline void perf_counter_notify(struct pt_regs *regs)            { }
 250 static inline void perf_counter_print_debug(void)                       { }
 251 static inline void hw_perf_restore(u64 ctrl)                    { }
 252 static inline u64 hw_perf_save_disable(void)                  { return 0; }
 253 static inline int perf_counter_task_disable(void)       { return -EINVAL; }
 254 static inline int perf_counter_task_enable(void)        { return -EINVAL; }
 255 #endif
 256
 257 #endif /* _LINUX_PERF_COUNTER_H */