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   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/ioctl.h>
  18
  19 #ifdef CONFIG_PERF_COUNTERS
  20 # include <asm/perf_counter.h>
  21 #endif
  22
  23 #include <linux/list.h>
  24 #include <linux/mutex.h>
  25 #include <linux/rculist.h>
  26 #include <linux/rcupdate.h>
  27 #include <linux/spinlock.h>
  28
  29 struct task_struct;
  30
  31 /*
  32  * User-space ABI bits:
  33  */
  34
  35 /*
  36  * Generalized performance counter event types, used by the hw_event.type
  37  * parameter of the sys_perf_counter_open() syscall:
  38  */
  39 enum hw_event_types {
  40         /*
  41          * Common hardware events, generalized by the kernel:
  42          */
  43         PERF_COUNT_CPU_CYCLES           =  0,
  44         PERF_COUNT_INSTRUCTIONS         =  1,
  45         PERF_COUNT_CACHE_REFERENCES     =  2,
  46         PERF_COUNT_CACHE_MISSES         =  3,
  47         PERF_COUNT_BRANCH_INSTRUCTIONS  =  4,
  48         PERF_COUNT_BRANCH_MISSES        =  5,
  49         PERF_COUNT_BUS_CYCLES           =  6,
  50
  51         PERF_HW_EVENTS_MAX              =  7,
  52
  53         /*
  54          * Special "software" counters provided by the kernel, even if
  55          * the hardware does not support performance counters. These
  56          * counters measure various physical and sw events of the
  57          * kernel (and allow the profiling of them as well):
  58          */
  59         PERF_COUNT_CPU_CLOCK            = -1,
  60         PERF_COUNT_TASK_CLOCK           = -2,
  61         PERF_COUNT_PAGE_FAULTS          = -3,
  62         PERF_COUNT_CONTEXT_SWITCHES     = -4,
  63         PERF_COUNT_CPU_MIGRATIONS       = -5,
  64
  65         PERF_SW_EVENTS_MIN              = -6,
  66 };
  67
  68 /*
  69  * IRQ-notification data record type:
  70  */
  71 enum perf_counter_record_type {
  72         PERF_RECORD_SIMPLE              =  0,
  73         PERF_RECORD_IRQ                 =  1,
  74         PERF_RECORD_GROUP               =  2,
  75 };
  76
  77 /*
  78  * Hardware event to monitor via a performance monitoring counter:
  79  */
  80 struct perf_counter_hw_event {
  81         s64                     type;
  82
  83         u64                     irq_period;
  84         u32                     record_type;
  85
  86         u32                     disabled       :  1, /* off by default        */
  87                                 nmi            :  1, /* NMI sampling          */
  88                                 raw            :  1, /* raw event type        */
  89                                 inherit        :  1, /* children inherit it   */
  90                                 pinned         :  1, /* must always be on PMU */
  91                                 exclusive      :  1, /* only group on PMU     */
  92                                 exclude_user   :  1, /* don't count user      */
  93                                 exclude_kernel :  1, /* ditto kernel          */
  94                                 exclude_hv     :  1, /* ditto hypervisor      */
  95
  96                                 __reserved_1 : 23;
  97
  98         u64                     __reserved_2;
  99 };
 100
 101 /*
 102  * Ioctls that can be done on a perf counter fd:
 103  */
 104 #define PERF_COUNTER_IOC_ENABLE         _IO('$', 0)
 105 #define PERF_COUNTER_IOC_DISABLE        _IO('$', 1)
 106
 107 /*
 108  * Kernel-internal data types:
 109  */
 110
 111 /**
 112  * struct hw_perf_counter - performance counter hardware details:
 113  */
 114 struct hw_perf_counter {
 115 #ifdef CONFIG_PERF_COUNTERS
 116         u64                             config;
 117         unsigned long                   config_base;
 118         unsigned long                   counter_base;
 119         int                             nmi;
 120         unsigned int                    idx;
 121         atomic64_t                      prev_count;
 122         u64                             irq_period;
 123         atomic64_t                      period_left;
 124 #endif
 125 };
 126
 127 /*
 128  * Hardcoded buffer length limit for now, for IRQ-fed events:
 129  */
 130 #define PERF_DATA_BUFLEN                2048
 131
 132 /**
 133  * struct perf_data - performance counter IRQ data sampling ...
 134  */
 135 struct perf_data {
 136         int                             len;
 137         int                             rd_idx;
 138         int                             overrun;
 139         u8                              data[PERF_DATA_BUFLEN];
 140 };
 141
 142 struct perf_counter;
 143
 144 /**
 145  * struct hw_perf_counter_ops - performance counter hw ops
 146  */
 147 struct hw_perf_counter_ops {
 148         int (*enable)                   (struct perf_counter *counter);
 149         void (*disable)                 (struct perf_counter *counter);
 150         void (*read)                    (struct perf_counter *counter);
 151 };
 152
 153 /**
 154  * enum perf_counter_active_state - the states of a counter
 155  */
 156 enum perf_counter_active_state {
 157         PERF_COUNTER_STATE_ERROR        = -2,
 158         PERF_COUNTER_STATE_OFF          = -1,
 159         PERF_COUNTER_STATE_INACTIVE     =  0,
 160         PERF_COUNTER_STATE_ACTIVE       =  1,
 161 };
 162
 163 struct file;
 164
 165 /**
 166  * struct perf_counter - performance counter kernel representation:
 167  */
 168 struct perf_counter {
 169 #ifdef CONFIG_PERF_COUNTERS
 170         struct list_head                list_entry;
 171         struct list_head                sibling_list;
 172         struct perf_counter             *group_leader;
 173         const struct hw_perf_counter_ops *hw_ops;
 174
 175         enum perf_counter_active_state  state;
 176         atomic64_t                      count;
 177
 178         struct perf_counter_hw_event    hw_event;
 179         struct hw_perf_counter          hw;
 180
 181         struct perf_counter_context     *ctx;
 182         struct task_struct              *task;
 183         struct file                     *filp;
 184
 185         struct perf_counter             *parent;
 186         struct list_head                child_list;
 187
 188         /*
 189          * Protect attach/detach and child_list:
 190          */
 191         struct mutex                    mutex;
 192
 193         int                             oncpu;
 194         int                             cpu;
 195
 196         /* read() / irq related data */
 197         wait_queue_head_t               waitq;
 198         /* optional: for NMIs */
 199         int                             wakeup_pending;
 200         struct perf_data                *irqdata;
 201         struct perf_data                *usrdata;
 202         struct perf_data                data[2];
 203 #endif
 204 };
 205
 206 /**
 207  * struct perf_counter_context - counter context structure
 208  *
 209  * Used as a container for task counters and CPU counters as well:
 210  */
 211 struct perf_counter_context {
 212 #ifdef CONFIG_PERF_COUNTERS
 213         /*
 214          * Protect the states of the counters in the list,
 215          * nr_active, and the list:
 216          */
 217         spinlock_t              lock;
 218         /*
 219          * Protect the list of counters.  Locking either mutex or lock
 220          * is sufficient to ensure the list doesn't change; to change
 221          * the list you need to lock both the mutex and the spinlock.
 222          */
 223         struct mutex            mutex;
 224
 225         struct list_head        counter_list;
 226         int                     nr_counters;
 227         int                     nr_active;
 228         int                     is_active;
 229         struct task_struct      *task;
 230 #endif
 231 };
 232
 233 /**
 234  * struct perf_counter_cpu_context - per cpu counter context structure
 235  */
 236 struct perf_cpu_context {
 237         struct perf_counter_context     ctx;
 238         struct perf_counter_context     *task_ctx;
 239         int                             active_oncpu;
 240         int                             max_pertask;
 241         int                             exclusive;
 242 };
 243
 244 /*
 245  * Set by architecture code:
 246  */
 247 extern int perf_max_counters;
 248
 249 #ifdef CONFIG_PERF_COUNTERS
 250 extern const struct hw_perf_counter_ops *
 251 hw_perf_counter_init(struct perf_counter *counter);
 252
 253 extern void perf_counter_task_sched_in(struct task_struct *task, int cpu);
 254 extern void perf_counter_task_sched_out(struct task_struct *task, int cpu);
 255 extern void perf_counter_task_tick(struct task_struct *task, int cpu);
 256 extern void perf_counter_init_task(struct task_struct *child);
 257 extern void perf_counter_exit_task(struct task_struct *child);
 258 extern void perf_counter_notify(struct pt_regs *regs);
 259 extern void perf_counter_print_debug(void);
 260 extern void perf_counter_unthrottle(void);
 261 extern u64 hw_perf_save_disable(void);
 262 extern void hw_perf_restore(u64 ctrl);
 263 extern int perf_counter_task_disable(void);
 264 extern int perf_counter_task_enable(void);
 265 extern int hw_perf_group_sched_in(struct perf_counter *group_leader,
 266                struct perf_cpu_context *cpuctx,
 267                struct perf_counter_context *ctx, int cpu);
 268
 269 /*
 270  * Return 1 for a software counter, 0 for a hardware counter
 271  */
 272 static inline int is_software_counter(struct perf_counter *counter)
 273 {
 274         return !counter->hw_event.raw && counter->hw_event.type < 0;
 275 }
 276
 277 #else
 278 static inline void
 279 perf_counter_task_sched_in(struct task_struct *task, int cpu)           { }
 280 static inline void
 281 perf_counter_task_sched_out(struct task_struct *task, int cpu)          { }
 282 static inline void
 283 perf_counter_task_tick(struct task_struct *task, int cpu)               { }
 284 static inline void perf_counter_init_task(struct task_struct *child)    { }
 285 static inline void perf_counter_exit_task(struct task_struct *child)    { }
 286 static inline void perf_counter_notify(struct pt_regs *regs)            { }
 287 static inline void perf_counter_print_debug(void)                       { }
 288 static inline void perf_counter_unthrottle(void)                        { }
 289 static inline void hw_perf_restore(u64 ctrl)                    { }
 290 static inline u64 hw_perf_save_disable(void)                  { return 0; }
 291 static inline int perf_counter_task_disable(void)       { return -EINVAL; }
 292 static inline int perf_counter_task_enable(void)        { return -EINVAL; }
 293 #endif
 294
 295 #endif /* _LINUX_PERF_COUNTER_H */