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