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