[lttng-modules.git] / ltt-tracer.h

/*
 * Copyright (C) 2005,2006,2008 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
 *
 * This contains the definitions for the Linux Trace Toolkit tracer.
 *
 * Dual LGPL v2.1/GPL v2 license.
 */

#ifndef _LTT_TRACER_H
#define _LTT_TRACER_H

#include <stdarg.h>
#include <linux/types.h>
#include <linux/limits.h>
#include <linux/list.h>
#include <linux/cache.h>
#include <linux/timex.h>
#include <linux/wait.h>
#include <asm/atomic.h>
#include <asm/local.h>

#include "wrapper/trace-clock.h"
#include "ltt-tracer-core.h"
#include "ltt-events.h"

#ifndef CHAR_BIT
#define CHAR_BIT 8
#endif

/* Number of bytes to log with a read/write event */
#define LTT_LOG_RW_SIZE			32L

/* Maximum number of callbacks per marker */
#define LTT_NR_CALLBACKS	10

struct ltt_serialize_closure;

/* Serialization callback */
typedef size_t (*ltt_serialize_cb)(struct lib_ring_buffer *buf,
				   size_t buf_offset,
				   struct ltt_serialize_closure *closure,
				   void *serialize_private,
				   unsigned int stack_pos_ctx,
				   int *largest_align,
				   const char *fmt, va_list *args);

struct ltt_serialize_closure {
	ltt_serialize_cb *callbacks;
	long cb_args[LTT_NR_CALLBACKS];
	unsigned int cb_idx;
};

size_t ltt_serialize_data(struct lib_ring_buffer *buf, size_t buf_offset,
			  struct ltt_serialize_closure *closure,
			  void *serialize_private, unsigned int stack_pos_ctx,
			  int *largest_align, const char *fmt, va_list *args);

enum ltt_channels {
	LTT_CHANNEL_METADATA,
	LTT_CHANNEL_FD_STATE,
	LTT_CHANNEL_GLOBAL_STATE,
	LTT_CHANNEL_IRQ_STATE,
	LTT_CHANNEL_MODULE_STATE,
	LTT_CHANNEL_NETIF_STATE,
	LTT_CHANNEL_SOFTIRQ_STATE,
	LTT_CHANNEL_SWAP_STATE,
	LTT_CHANNEL_SYSCALL_STATE,
	LTT_CHANNEL_TASK_STATE,
	LTT_CHANNEL_VM_STATE,
	LTT_CHANNEL_FS,
	LTT_CHANNEL_INPUT,
	LTT_CHANNEL_IPC,
	LTT_CHANNEL_KERNEL,
	LTT_CHANNEL_MM,
	LTT_CHANNEL_RCU,
	LTT_CHANNEL_DEFAULT,
};

/*
 * Hardcoded event headers
 *
 * event header for a trace with active heartbeat : 27 bits timestamps
 *
 * headers are 32-bits aligned. In order to insure such alignment, a dynamic per
 * trace alignment value must be done.
 *
 * Remember that the C compiler does align each member on the boundary
 * equivalent to their own size.
 *
 * As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
 * bytes aligned, so the buffer header and trace header are aligned.
 *
 * Event headers are aligned depending on the trace alignment option.
 *
 * Note using C structure bitfields for cross-endianness and portability
 * concerns.
 */

#define LTT_RESERVED_EVENTS	3
#define LTT_EVENT_BITS		5
#define LTT_FREE_EVENTS		((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
#define LTT_TSC_BITS		27
#define LTT_TSC_MASK		((1 << LTT_TSC_BITS) - 1)

struct event_header {
	u32 id_time;		/* 5 bits event id (MSB); 27 bits time (LSB) */
};

/* Reservation flags */
#define	LTT_RFLAG_ID			(1 << 0)
#define	LTT_RFLAG_ID_SIZE		(1 << 1)
#define	LTT_RFLAG_ID_SIZE_TSC		(1 << 2)

#define LTT_MAX_SMALL_SIZE		0xFFFFU

static inline
size_t ltt_get_header_alignment(void)
{
#ifdef RING_BUFFER_ALIGN
	return sizeof(struct event_header) * CHAR_BIT;
#else
	return CHAR_BIT;
#endif
}

/*
 * We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
 * specifically with CPU frequency scaling someday, so using an interpolation
 * between the start and end of buffer values is not flexible enough. Using an
 * immediate frequency value permits to calculate directly the times for parts
 * of a buffer that would be before a frequency change.
 *
 * Keep the natural field alignment for _each field_ within this structure if
 * you ever add/remove a field from this header. Packed attribute is not used
 * because gcc generates poor code on at least powerpc and mips. Don't ever
 * let gcc add padding between the structure elements.
 */
struct packet_header {
	uint32_t magic;			/*
					 * Trace magic number.
					 * contains endianness information.
					 */
	uint8_t trace_uuid[16];
	uint32_t stream_id;
	uint64_t timestamp_begin;	/* Cycle count at subbuffer start */
	uint64_t timestamp_end;	/* Cycle count at subbuffer end */
	uint32_t content_size;		/* Size of data in subbuffer */
	uint32_t packet_size;		/* Subbuffer size (include padding) */
	uint32_t events_lost;		/*
					 * Events lost in this subbuffer since
					 * the beginning of the trace.
					 * (may overflow)
					 */
	/* TODO: move to metadata */
#if 0
	uint8_t major_version;
	uint8_t minor_version;
	uint8_t arch_size;		/* Architecture pointer size */
	uint8_t alignment;		/* LTT data alignment */
	uint64_t start_time_sec;	/* NTP-corrected start time */
	uint64_t start_time_usec;
	uint64_t start_freq;		/*
					 * Frequency at trace start,
					 * used all along the trace.
					 */
	uint32_t freq_scale;		/* Frequency scaling (divisor) */
#endif //0
	uint8_t header_end[0];		/* End of header */
};

/* Tracer properties */
#define CTF_MAGIC_NUMBER		0xC1FC1FC1
#define TSDL_MAGIC_NUMBER		0x75D11D57
#define LTT_TRACER_VERSION_MAJOR	3
#define LTT_TRACER_VERSION_MINOR	0

/*
 * Number of milliseconds to retry before failing metadata writes on buffer full
 * condition. (10 seconds)
 */
#define LTTNG_METADATA_TIMEOUT_MSEC	10000

/*
 * Size reserved for high priority events (interrupts, NMI, BH) at the end of a
 * nearly full buffer. User space won't use this last amount of space when in
 * blocking mode. This space also includes the event header that would be
 * written by this user space event.
 */
#define LTT_RESERVE_CRITICAL		4096

/* Register and unregister function pointers */

enum ltt_module_function {
	LTT_FUNCTION_RUN_FILTER,
	LTT_FUNCTION_FILTER_CONTROL,
	LTT_FUNCTION_STATEDUMP
};

extern int ltt_module_register(enum ltt_module_function name, void *function,
			       struct module *owner);
extern void ltt_module_unregister(enum ltt_module_function name);

/* Exported control function */

void ltt_core_register(int (*function)(u8, void *));

void ltt_core_unregister(void);

extern
void ltt_statedump_register_kprobes_dump(void (*callback)(void *call_data));
extern
void ltt_statedump_unregister_kprobes_dump(void (*callback)(void *call_data));

extern void ltt_dump_softirq_vec(void *call_data);

#ifdef CONFIG_HAVE_LTT_DUMP_TABLES
extern void ltt_dump_sys_call_table(void *call_data);
extern void ltt_dump_idt_table(void *call_data);
#else
static inline void ltt_dump_sys_call_table(void *call_data)
{
}

static inline void ltt_dump_idt_table(void *call_data)
{
}
#endif

#endif /* _LTT_TRACER_H */
Commit	Line	Data
1c8284eb MD	1	/*
	2	* Copyright (C) 2005,2006,2008 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
	3	*
	4	* This contains the definitions for the Linux Trace Toolkit tracer.
	5	*
	6	* Dual LGPL v2.1/GPL v2 license.
	7	*/
	8
	9	#ifndef _LTT_TRACER_H
	10	#define _LTT_TRACER_H
	11
	12	#include <stdarg.h>
	13	#include <linux/types.h>
	14	#include <linux/limits.h>
	15	#include <linux/list.h>
	16	#include <linux/cache.h>
1c8284eb MD	17	#include <linux/timex.h>
1c8284eb MD	18	#include <linux/wait.h>
1c8284eb MD	19	#include <asm/atomic.h>
	20	#include <asm/local.h>
	21
f3bc08c5	22	#include "wrapper/trace-clock.h"
1c8284eb	23	#include "ltt-tracer-core.h"
1c25284c	24	#include "ltt-events.h"
1c8284eb	25
c099397a MD	26	#ifndef CHAR_BIT
	27	#define CHAR_BIT 8
	28	#endif
	29
1c8284eb MD	30	/* Number of bytes to log with a read/write event */
	31	#define LTT_LOG_RW_SIZE 32L
	32
1c8284eb MD	33	/* Maximum number of callbacks per marker */
	34	#define LTT_NR_CALLBACKS 10
	35
11b5a3c2 MD	36	struct ltt_serialize_closure;
	37
	38	/* Serialization callback */
	39	typedef size_t (ltt_serialize_cb)(struct lib_ring_buffer buf,
	40	size_t buf_offset,
	41	struct ltt_serialize_closure *closure,
	42	void *serialize_private,
	43	unsigned int stack_pos_ctx,
	44	int *largest_align,
	45	const char fmt, va_list args);
	46
1c8284eb MD	47	struct ltt_serialize_closure {
	48	ltt_serialize_cb *callbacks;
	49	long cb_args[LTT_NR_CALLBACKS];
	50	unsigned int cb_idx;
	51	};
	52
11b5a3c2	53	size_t ltt_serialize_data(struct lib_ring_buffer *buf, size_t buf_offset,
1c8284eb MD	54	struct ltt_serialize_closure *closure,
	55	void *serialize_private, unsigned int stack_pos_ctx,
	56	int largest_align, const char fmt, va_list *args);
	57
1c8284eb MD	58	enum ltt_channels {
	59	LTT_CHANNEL_METADATA,
	60	LTT_CHANNEL_FD_STATE,
	61	LTT_CHANNEL_GLOBAL_STATE,
	62	LTT_CHANNEL_IRQ_STATE,
	63	LTT_CHANNEL_MODULE_STATE,
	64	LTT_CHANNEL_NETIF_STATE,
	65	LTT_CHANNEL_SOFTIRQ_STATE,
	66	LTT_CHANNEL_SWAP_STATE,
	67	LTT_CHANNEL_SYSCALL_STATE,
	68	LTT_CHANNEL_TASK_STATE,
	69	LTT_CHANNEL_VM_STATE,
	70	LTT_CHANNEL_FS,
	71	LTT_CHANNEL_INPUT,
	72	LTT_CHANNEL_IPC,
	73	LTT_CHANNEL_KERNEL,
	74	LTT_CHANNEL_MM,
	75	LTT_CHANNEL_RCU,
	76	LTT_CHANNEL_DEFAULT,
	77	};
	78
7514523f MD	79	/*
7514523f MD	80	* Hardcoded event headers
1c8284eb MD	81	*
	82	* event header for a trace with active heartbeat : 27 bits timestamps
	83	*
	84	* headers are 32-bits aligned. In order to insure such alignment, a dynamic per
	85	* trace alignment value must be done.
	86	*
	87	* Remember that the C compiler does align each member on the boundary
	88	* equivalent to their own size.
	89	*
	90	* As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
	91	* bytes aligned, so the buffer header and trace header are aligned.
	92	*
	93	* Event headers are aligned depending on the trace alignment option.
	94	*
	95	* Note using C structure bitfields for cross-endianness and portability
	96	* concerns.
	97	*/
	98
	99	#define LTT_RESERVED_EVENTS 3
	100	#define LTT_EVENT_BITS 5
	101	#define LTT_FREE_EVENTS ((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
	102	#define LTT_TSC_BITS 27
	103	#define LTT_TSC_MASK ((1 << LTT_TSC_BITS) - 1)
	104
7514523f	105	struct event_header {
1c8284eb MD	106	u32 id_time; /* 5 bits event id (MSB); 27 bits time (LSB) */
	107	};
	108
	109	/* Reservation flags */
	110	#define LTT_RFLAG_ID (1 << 0)
	111	#define LTT_RFLAG_ID_SIZE (1 << 1)
	112	#define LTT_RFLAG_ID_SIZE_TSC (1 << 2)
	113
	114	#define LTT_MAX_SMALL_SIZE 0xFFFFU
	115
c099397a MD	116	static inline
	117	size_t ltt_get_header_alignment(void)
	118	{
	119	#ifdef RING_BUFFER_ALIGN
	120	return sizeof(struct event_header) * CHAR_BIT;
	121	#else
	122	return CHAR_BIT;
	123	#endif
	124	}
	125
1c8284eb MD	126	/*
	127	* We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
	128	* specifically with CPU frequency scaling someday, so using an interpolation
	129	* between the start and end of buffer values is not flexible enough. Using an
	130	* immediate frequency value permits to calculate directly the times for parts
	131	* of a buffer that would be before a frequency change.
	132	*
	133	* Keep the natural field alignment for _each field_ within this structure if
	134	* you ever add/remove a field from this header. Packed attribute is not used
	135	* because gcc generates poor code on at least powerpc and mips. Don't ever
	136	* let gcc add padding between the structure elements.
	137	*/
1c25284c MD	138	struct packet_header {
1c25284c MD	139	uint32_t magic; /*
1c8284eb MD	140	* Trace magic number.
	141	* contains endianness information.
	142	*/
1c25284c MD	143	uint8_t trace_uuid[16];
	144	uint32_t stream_id;
	145	uint64_t timestamp_begin; /* Cycle count at subbuffer start */
	146	uint64_t timestamp_end; /* Cycle count at subbuffer end */
	147	uint32_t content_size; /* Size of data in subbuffer */
	148	uint32_t packet_size; /* Subbuffer size (include padding) */
	149	uint32_t events_lost; /*
	150	* Events lost in this subbuffer since
	151	* the beginning of the trace.
	152	* (may overflow)
	153	*/
	154	/* TODO: move to metadata */
	155	#if 0
1c8284eb MD	156	uint8_t major_version;
	157	uint8_t minor_version;
	158	uint8_t arch_size; /* Architecture pointer size */
	159	uint8_t alignment; /* LTT data alignment */
	160	uint64_t start_time_sec; /* NTP-corrected start time */
	161	uint64_t start_time_usec;
	162	uint64_t start_freq; /*
	163	* Frequency at trace start,
	164	* used all along the trace.
	165	*/
	166	uint32_t freq_scale; /* Frequency scaling (divisor) */
1c25284c	167	#endif //0
1c8284eb MD	168	uint8_t header_end[0]; /* End of header */
	169	};
	170
1c8284eb	171	/* Tracer properties */
1c25284c	172	#define CTF_MAGIC_NUMBER 0xC1FC1FC1
881833e3	173	#define TSDL_MAGIC_NUMBER 0x75D11D57
1c25284c MD	174	#define LTT_TRACER_VERSION_MAJOR 3
1c25284c MD	175	#define LTT_TRACER_VERSION_MINOR 0
1c8284eb	176
c099397a MD	177	/*
	178	* Number of milliseconds to retry before failing metadata writes on buffer full
	179	* condition. (10 seconds)
	180	*/
	181	#define LTTNG_METADATA_TIMEOUT_MSEC 10000
	182
1c8284eb MD	183	/*
	184	* Size reserved for high priority events (interrupts, NMI, BH) at the end of a
	185	* nearly full buffer. User space won't use this last amount of space when in
	186	* blocking mode. This space also includes the event header that would be
	187	* written by this user space event.
	188	*/
	189	#define LTT_RESERVE_CRITICAL 4096
	190
	191	/* Register and unregister function pointers */
	192
	193	enum ltt_module_function {
	194	LTT_FUNCTION_RUN_FILTER,
	195	LTT_FUNCTION_FILTER_CONTROL,
	196	LTT_FUNCTION_STATEDUMP
	197	};
	198
	199	extern int ltt_module_register(enum ltt_module_function name, void *function,
	200	struct module *owner);
	201	extern void ltt_module_unregister(enum ltt_module_function name);
	202
1c8284eb MD	203	/* Exported control function */
1c8284eb MD	204
1c8284eb MD	205	void ltt_core_register(int (function)(u8, void ));
	206
	207	void ltt_core_unregister(void);
	208
1c8284eb MD	209	extern
	210	void ltt_statedump_register_kprobes_dump(void (callback)(void call_data));
	211	extern
	212	void ltt_statedump_unregister_kprobes_dump(void (callback)(void call_data));
	213
	214	extern void ltt_dump_softirq_vec(void *call_data);
	215
f277b4c1	216	#ifdef CONFIG_HAVE_LTT_DUMP_TABLES
1c8284eb MD	217	extern void ltt_dump_sys_call_table(void *call_data);
1c8284eb MD	218	extern void ltt_dump_idt_table(void *call_data);
f277b4c1 MD	219	#else
	220	static inline void ltt_dump_sys_call_table(void *call_data)
	221	{
	222	}
	223
	224	static inline void ltt_dump_idt_table(void *call_data)
	225	{
	226	}
	227	#endif
1c8284eb	228
1c8284eb	229	#endif /* _LTT_TRACER_H */