libtracing/tracercore.h

   1 /*
   2  * Copyright (C) 2005,2006 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
   3  *
   4  * This contains the core definitions for the Linux Trace Toolkit.
   5  */
   6
   7 #ifndef LTT_CORE_H
   8 #define LTT_CORE_H
   9
  10 #include "list.h"
  11 //ust// #include <linux/percpu.h>
  12
  13 /* ltt's root dir in debugfs */
  14 #define LTT_ROOT        "ltt"
  15
  16 /*
  17  * All modifications of ltt_traces must be done by ltt-tracer.c, while holding
  18  * the semaphore. Only reading of this information can be done elsewhere, with
  19  * the RCU mechanism : the preemption must be disabled while reading the
  20  * list.
  21  */
  22 struct ltt_traces {
  23         struct list_head setup_head;    /* Pre-allocated traces list */
  24         struct list_head head;          /* Allocated Traces list */
  25         unsigned int num_active_traces; /* Number of active traces */
  26 } ____cacheline_aligned;
  27
  28 extern struct ltt_traces ltt_traces;
  29
  30 /*
  31  * get dentry of ltt's root dir
  32  */
  33 struct dentry *get_ltt_root(void);
  34
  35 /* Keep track of trap nesting inside LTT */
  36 //ust// DECLARE_PER_CPU(unsigned int, ltt_nesting);
  37
  38 typedef int (*ltt_run_filter_functor)(void *trace, uint16_t eID);
  39
  40 extern ltt_run_filter_functor ltt_run_filter;
  41
  42 extern void ltt_filter_register(ltt_run_filter_functor func);
  43 extern void ltt_filter_unregister(void);
  44
  45 #if defined(CONFIG_LTT) && defined(CONFIG_LTT_ALIGNMENT)
  46
  47 /*
  48  * Calculate the offset needed to align the type.
  49  * size_of_type must be non-zero.
  50  */
  51 static inline unsigned int ltt_align(size_t align_drift, size_t size_of_type)
  52 {
  53         size_t alignment = min(sizeof(void *), size_of_type);
  54         return (alignment - align_drift) & (alignment - 1);
  55 }
  56 /* Default arch alignment */
  57 #define LTT_ALIGN
  58
  59 static inline int ltt_get_alignment(void)
  60 {
  61         return sizeof(void *);
  62 }
  63
  64 #else
  65
  66 static inline unsigned int ltt_align(size_t align_drift,
  67                  size_t size_of_type)
  68 {
  69         return 0;
  70 }
  71
  72 #define LTT_ALIGN __attribute__((packed))
  73
  74 static inline int ltt_get_alignment(void)
  75 {
  76         return 0;
  77 }
  78 #endif /* defined(CONFIG_LTT) && defined(CONFIG_LTT_ALIGNMENT) */
  79
  80 #endif /* LTT_CORE_H */