Linux Kernel Markers: support multiple probes

[linux-flexiantxendom0-natty.git] / include / linux / marker.h

diff --git a/include/linux/marker.h b/include/linux/marker.h
index 5f36cf9..b5f9563 100644 (file)
--- a/include/linux/marker.h
+++ b/include/linux/marker.h
@@ -19,16 +19,23 @@ struct marker;
 
 /**
  * marker_probe_func - Type of a marker probe function
- * @mdata: pointer of type struct marker
- * @private_data: caller site private data
+ * @probe_private: probe private data
+ * @call_private: call site private data
  * @fmt: format string
- * @...: variable argument list
+ * @args: variable argument list pointer. Use a pointer to overcome C's
+ *        inability to pass this around as a pointer in a portable manner in
+ *        the callee otherwise.
  *
  * Type of marker probe functions. They receive the mdata and need to parse the
  * format string to recover the variable argument list.
  */
-typedef void marker_probe_func(const struct marker *mdata,
-       void *private_data, const char *fmt, ...);
+typedef void marker_probe_func(void *probe_private, void *call_private,
+               const char *fmt, va_list *args);
+
+struct marker_probe_closure {
+       marker_probe_func *func;        /* Callback */
+       void *probe_private;            /* Private probe data */
+};
 
 struct marker {
        const char *name;       /* Marker name */
@@ -36,8 +43,11 @@ struct marker {
                                 * variable argument list.
                                 */
        char state;             /* Marker state. */
-       marker_probe_func *call;/* Probe handler function pointer */
-       void *private;          /* Private probe data */
+       char ptype;             /* probe type : 0 : single, 1 : multi */
+       void (*call)(const struct marker *mdata,        /* Probe wrapper */
+               void *call_private, const char *fmt, ...);
+       struct marker_probe_closure single;
+       struct marker_probe_closure *multi;
 } __attribute__((aligned(8)));
 
 #ifdef CONFIG_MARKERS
@@ -49,7 +59,7 @@ struct marker {
  * not add unwanted padding between the beginning of the section and the
  * structure. Force alignment to the same alignment as the section start.
  */
-#define __trace_mark(name, call_data, format, args...)                 \
+#define __trace_mark(name, call_private, format, args...)              \
        do {                                                            \
                static const char __mstrtab_name_##name[]               \
                __attribute__((section("__markers_strings")))           \
@@ -60,24 +70,23 @@ struct marker {
                static struct marker __mark_##name                      \
                __attribute__((section("__markers"), aligned(8))) =     \
                { __mstrtab_name_##name, __mstrtab_format_##name,       \
-               0, __mark_empty_function, NULL };                       \
+               0, 0, marker_probe_cb,                                  \
+               { __mark_empty_function, NULL}, NULL };                 \
                __mark_check_format(format, ## args);                   \
                if (unlikely(__mark_##name.state)) {                    \
-                       preempt_disable();                              \
                        (*__mark_##name.call)                           \
-                               (&__mark_##name, call_data,             \
+                               (&__mark_##name, call_private,          \
                                format, ## args);                       \
-                       preempt_enable();                               \
                }                                                       \
        } while (0)
 
 extern void marker_update_probe_range(struct marker *begin,
-       struct marker *end, struct module *probe_module, int *refcount);
+       struct marker *end);
 #else /* !CONFIG_MARKERS */
-#define __trace_mark(name, call_data, format, args...) \
+#define __trace_mark(name, call_private, format, args...) \
                __mark_check_format(format, ## args)
 static inline void marker_update_probe_range(struct marker *begin,
-       struct marker *end, struct module *probe_module, int *refcount)
+       struct marker *end)
 { }
 #endif /* CONFIG_MARKERS */
 
@@ -92,8 +101,6 @@ static inline void marker_update_probe_range(struct marker *begin,
 #define trace_mark(name, format, args...) \
        __trace_mark(name, NULL, format, ## args)
 
-#define MARK_MAX_FORMAT_LEN    1024
-
 /**
  * MARK_NOARGS - Format string for a marker with no argument.
  */
@@ -106,24 +113,30 @@ static inline void __printf(1, 2) __mark_check_format(const char *fmt, ...)
 
 extern marker_probe_func __mark_empty_function;
 
+extern void marker_probe_cb(const struct marker *mdata,
+       void *call_private, const char *fmt, ...);
+extern void marker_probe_cb_noarg(const struct marker *mdata,
+       void *call_private, const char *fmt, ...);
+
 /*
  * Connect a probe to a marker.
  * private data pointer must be a valid allocated memory address, or NULL.
  */
 extern int marker_probe_register(const char *name, const char *format,
-                               marker_probe_func *probe, void *private);
+                               marker_probe_func *probe, void *probe_private);
 
 /*
  * Returns the private data given to marker_probe_register.
  */
-extern void *marker_probe_unregister(const char *name);
+extern int marker_probe_unregister(const char *name,
+       marker_probe_func *probe, void *probe_private);
 /*
  * Unregister a marker by providing the registered private data.
  */
-extern void *marker_probe_unregister_private_data(void *private);
+extern int marker_probe_unregister_private_data(marker_probe_func *probe,
+       void *probe_private);
 
-extern int marker_arm(const char *name);
-extern int marker_disarm(const char *name);
-extern void *marker_get_private_data(const char *name);
+extern void *marker_get_private_data(const char *name, marker_probe_func *probe,
+       int num);
 
 #endif