[ust.git] / libust / tracer.h

/*
 * Copyright (C) 2005,2006,2008 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
 * Copyright (C) 2009 Pierre-Marc Fournier
 *
 * This contains the definitions for the Linux Trace Toolkit tracer.
 *
 * Ported to userspace by Pierre-Marc Fournier.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 */

#ifndef _LTT_TRACER_H
#define _LTT_TRACER_H

#include <sys/types.h>
#include <stdarg.h>
#include <ust/marker.h>
#include <ust/marker-internal.h>
#include <ust/probe-internal.h>
#include <ust/core.h>
#include <ust/compat.h>
#include "channels.h"
#include "tracercore.h"
#include "tracerconst.h"
#include "buffers.h"

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

/* Interval (in jiffies) at which the LTT per-CPU timer fires */
#define LTT_PERCPU_TIMER_INTERVAL	1

#ifndef LTT_ARCH_TYPE
#define LTT_ARCH_TYPE			LTT_ARCH_TYPE_UNDEFINED
#endif

#ifndef LTT_ARCH_VARIANT
#define LTT_ARCH_VARIANT		LTT_ARCH_VARIANT_NONE
#endif

struct ltt_active_ust_marker;

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

struct ltt_serialize_closure;
struct ltt_probe_private_data;

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

extern size_t ltt_serialize_data(struct ust_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_probe_private_data {
	struct ust_trace *trace;	/*
					 * Target trace, for metadata
					 * or statedump.
					 */
	ltt_serialize_cb serializer;	/*
					 * Serialization function override.
					 */
	void *serialize_private;	/*
					 * Private data for serialization
					 * functions.
					 */
};

enum ltt_channels {
	LTT_CHANNEL_METADATA,
	LTT_CHANNEL_UST,
};

struct chan_info_struct {
	const char *name;
	unsigned int def_subbufsize;
	unsigned int def_subbufcount;
};

struct ltt_active_ust_marker {
	struct cds_list_head node;		/* active markers list */
	const char *channel;
	const char *name;
	const char *format;
	struct ltt_available_probe *probe;
};

struct ust_marker; //ust//
extern void ltt_vtrace(const struct ust_marker *mdata, void *probe_data,
	void *call_data, const char *fmt, va_list *args);
extern void ltt_trace(const struct ust_marker *mdata, void *probe_data,
	void *call_data, const char *fmt, ...);

/*
 * Unique ID assigned to each registered probe.
 */
enum ust_marker_id {
	UST_MARKER_ID_SET_MARKER_ID = 0,	/* Static IDs available (range 0-7) */
	UST_MARKER_ID_SET_MARKER_FORMAT,
	UST_MARKER_ID_COMPACT,		/* Compact IDs (range: 8-127)	    */
	UST_MARKER_ID_DYNAMIC,		/* Dynamic IDs (range: 128-65535)   */
};

/* static ids 0-1 reserved for internal use. */
#define UST_MARKER_CORE_IDS		2
static __inline__ enum ust_marker_id ust_marker_id_type(uint16_t id)
{
	if (id < UST_MARKER_CORE_IDS)
		return (enum ust_marker_id)id;
	else
		return UST_MARKER_ID_DYNAMIC;
}

struct user_dbg_data {
	unsigned long avail_size;
	unsigned long write;
	unsigned long read;
};

struct ltt_trace_ops {
	/* First 32 bytes cache-hot cacheline */
	void (*wakeup_channel) (struct ust_channel *channel);
	int (*user_blocking) (struct ust_trace *trace,
				unsigned int index, size_t data_size,
				struct user_dbg_data *dbg);
	/* End of first 32 bytes cacheline */
	int (*create_dirs) (struct ust_trace *new_trace);
	void (*remove_dirs) (struct ust_trace *new_trace);
	int (*create_channel) (const char *trace_name,
				struct ust_trace *trace,
				const char *channel_name,
				struct ust_channel *channel,
				unsigned int subbuf_size,
				unsigned int n_subbufs, int overwrite);
	void (*finish_channel) (struct ust_channel *channel);
	void (*remove_channel) (struct ust_channel *channel);
	void (*user_errors) (struct ust_trace *trace,
				unsigned int index, size_t data_size,
				struct user_dbg_data *dbg, unsigned int cpu);
};

struct ltt_transport {
	char *name;
	struct module *owner;
	struct cds_list_head node;
	struct ltt_trace_ops ops;
};

enum trace_mode { LTT_TRACE_NORMAL, LTT_TRACE_FLIGHT, LTT_TRACE_HYBRID };

#define CHANNEL_FLAG_ENABLE	(1U<<0)
#define CHANNEL_FLAG_OVERWRITE	(1U<<1)

/* Per-trace information - each trace/flight recorder represented by one */
struct ust_trace {
	/* First 32 bytes cache-hot cacheline */
	struct cds_list_head list;
	struct ltt_trace_ops *ops;
	int active;
	/* Second 32 bytes cache-hot cacheline */
	struct ust_channel *channels;
	unsigned int nr_channels;
	u32 freq_scale;
	u64 start_freq;
	u64 start_tsc;
	unsigned long long start_monotonic;
	struct timeval		start_time;
	struct ltt_channel_setting *settings;
	struct {
		struct dentry			*trace_root;
	} dentry;
	struct urcu_ref urcu_ref; /* Each channel has a urcu_ref of the trace struct */
	struct ltt_transport *transport;
	struct urcu_ref ltt_transport_urcu_ref;
	char trace_name[NAME_MAX];
} ____cacheline_aligned;

/*
 * 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 ltt_subbuffer_header {
	uint64_t cycle_count_begin;	/* Cycle count at subbuffer start */
	uint64_t cycle_count_end;	/* Cycle count at subbuffer end */
	uint32_t magic_number;		/*
					 * Trace magic number.
					 * contains endianness information.
					 */
	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) */
	uint32_t data_size;		/* Size of data in subbuffer */
	uint32_t sb_size;		/* Subbuffer size (including padding) */
	uint32_t events_lost;		/*
					 * Events lost in this subbuffer since
					 * the beginning of the trace.
					 * (may overflow)
					 */
	uint32_t subbuf_corrupt;	/*
					 * Corrupted (lost) subbuffers since
					 * the begginig of the trace.
					 * (may overflow)
					 */
	uint8_t header_end[0];		/* End of header */
};

/**
 * ltt_subbuffer_header_size - called on buffer-switch to a new sub-buffer
 *
 * Return header size without padding after the structure. Don't use packed
 * structure because gcc generates inefficient code on some architectures
 * (powerpc, mips..)
 */
static __inline__ size_t ltt_subbuffer_header_size(void)
{
	return offsetof(struct ltt_subbuffer_header, header_end);
}

extern size_t ltt_write_event_header_slow(struct ust_channel *channel,
               struct ust_buffer *buf, long buf_offset,
               u16 eID, u32 event_size,
               u64 tsc, unsigned int rflags);


/*
 * ltt_write_event_header
 *
 * Writes the event header to the offset (already aligned on 32-bits).
 *
 * @trace : trace to write to.
 * @channel : pointer to the channel structure..
 * @buf : buffer to write to.
 * @buf_offset : buffer offset to write to (aligned on 32 bits).
 * @eID : event ID
 * @event_size : size of the event, excluding the event header.
 * @tsc : time stamp counter.
 * @rflags : reservation flags.
 *
 * returns : offset where the event data must be written.
 */
static __inline__ size_t ltt_write_event_header(struct ust_channel *chan,
		struct ust_buffer *buf, long buf_offset,
		u16 eID, u32 event_size,
		u64 tsc, unsigned int rflags)
{
	struct ltt_event_header header;

	if (unlikely(rflags))
		goto slow_path;

	header.id_time = eID << LTT_TSC_BITS;
	header.id_time |= (u32)tsc & LTT_TSC_MASK;
	ust_buffers_write(buf, buf_offset, &header, sizeof(header));
	buf_offset += sizeof(header);

	return buf_offset;

slow_path:
	return ltt_write_event_header_slow(chan, buf, buf_offset,
				eID, event_size, tsc, rflags);
}

/*
 * Control channels :
 * control/metadata
 * control/interrupts
 * control/...
 *
 * cpu channel :
 * cpu
 */

#define LTT_METADATA_CHANNEL		"metadata_state"
#define LTT_UST_CHANNEL			"ust"

#define LTT_FLIGHT_PREFIX	"flight-"

/* Tracer properties */
//#define LTT_DEFAULT_SUBBUF_SIZE_LOW	134217728
#define LTT_DEFAULT_SUBBUF_SIZE_LOW	65536
//#define LTT_DEFAULT_SUBBUF_SIZE_LOW	4096
#define LTT_DEFAULT_N_SUBBUFS_LOW	2
//#define LTT_DEFAULT_SUBBUF_SIZE_MED	134217728
#define LTT_DEFAULT_SUBBUF_SIZE_MED	262144
//#define LTT_DEFAULT_SUBBUF_SIZE_MED	4096
#define LTT_DEFAULT_N_SUBBUFS_MED	2
//#define LTT_DEFAULT_SUBBUF_SIZE_HIGH	134217728
#define LTT_DEFAULT_SUBBUF_SIZE_HIGH	1048576
//#define LTT_DEFAULT_SUBBUF_SIZE_HIGH	4096
#define LTT_DEFAULT_N_SUBBUFS_HIGH	2
#define LTT_TRACER_MAGIC_NUMBER		0x00D6B7ED
#define LTT_TRACER_VERSION_MAJOR	2
#define LTT_TRACER_VERSION_MINOR	6

/**
 * ust_write_trace_header - Write trace header
 * @trace: Trace information
 * @header: Memory address where the information must be written to
 */
static __inline__ void ltt_write_trace_header(struct ust_trace *trace,
               struct ltt_subbuffer_header *header)
{
	header->magic_number = LTT_TRACER_MAGIC_NUMBER;
	header->major_version = LTT_TRACER_VERSION_MAJOR;
	header->minor_version = LTT_TRACER_VERSION_MINOR;
	header->arch_size = sizeof(void *);
	header->alignment = ltt_get_alignment();
	header->start_time_sec = trace->start_time.tv_sec;
	header->start_time_usec = trace->start_time.tv_usec;
	header->start_freq = trace->start_freq;
	header->freq_scale = trace->freq_scale;
}

#ifndef UST_VALGRIND

static __inline__ int ust_get_cpu(void)
{
	int cpu;

	cpu = sched_getcpu();
	if (likely(cpu >= 0))
		return cpu;
	/*
	 * If getcpu(2) is not implemented in the Kernel use CPU 0 as fallback.
	 */
	return 0;
}

#else	/* #else #ifndef UST_VALGRIND */

static __inline__ int ust_get_cpu(void)
{
	/*
	 * Valgrind does not support the sched_getcpu() vsyscall.
	 * It causes it to detect a segfault in the program and stop it.
	 * So if we want to check libust with valgrind, we have to refrain
	 * from using this call. TODO: it would probably be better to return
	 * other values too, to better test it.
	 */
	return 0;
}

#endif	/* #else #ifndef UST_VALGRIND */

/*
 * 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 void ltt_transport_register(struct ltt_transport *transport);
extern void ltt_transport_unregister(struct ltt_transport *transport);

/* Exported control function */

union ltt_control_args {
	struct {
		enum trace_mode mode;
		unsigned int subbuf_size_low;
		unsigned int n_subbufs_low;
		unsigned int subbuf_size_med;
		unsigned int n_subbufs_med;
		unsigned int subbuf_size_high;
		unsigned int n_subbufs_high;
	} new_trace;
};

extern int _ltt_trace_setup(const char *trace_name);
extern int ltt_trace_setup(const char *trace_name);
extern struct ust_trace *_ltt_trace_find_setup(const char *trace_name);
extern int ltt_trace_set_type(const char *trace_name, const char *trace_type);
extern int ltt_trace_set_channel_subbufsize(const char *trace_name,
		const char *channel_name, unsigned int size);
extern int ltt_trace_set_channel_subbufcount(const char *trace_name,
		const char *channel_name, unsigned int cnt);
extern int ltt_trace_set_channel_enable(const char *trace_name,
		const char *channel_name, unsigned int enable);
extern int ltt_trace_set_channel_overwrite(const char *trace_name,
		const char *channel_name, unsigned int overwrite);
extern int ltt_trace_alloc(const char *trace_name);
extern int ltt_trace_destroy(const char *trace_name, int drop);
extern int ltt_trace_start(const char *trace_name);
extern int ltt_trace_stop(const char *trace_name);

enum ltt_filter_control_msg {
	LTT_FILTER_DEFAULT_ACCEPT,
	LTT_FILTER_DEFAULT_REJECT
};

extern int ltt_filter_control(enum ltt_filter_control_msg msg,
		const char *trace_name);

extern struct dentry *get_filter_root(void);

extern void ltt_write_trace_header(struct ust_trace *trace,
		struct ltt_subbuffer_header *header);
extern void ltt_buffer_destroy(struct ust_channel *ltt_chan);

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

extern void ltt_core_unregister(void);

extern void ltt_release_trace(struct urcu_ref *urcu_ref);
extern void ltt_release_transport(struct urcu_ref *urcu_ref);

extern void ltt_dump_ust_marker_state(struct ust_trace *trace);

extern void ltt_lock_traces(void);
extern void ltt_unlock_traces(void);

extern struct ust_trace *_ltt_trace_find(const char *trace_name);

#endif /* _LTT_TRACER_H */
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2005,2006,2008 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
	3	* Copyright (C) 2009 Pierre-Marc Fournier
	4	*
	5	* This contains the definitions for the Linux Trace Toolkit tracer.
	6	*
	7	* Ported to userspace by Pierre-Marc Fournier.
	8	*
	9	* This library is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU Lesser General Public
	11	* License as published by the Free Software Foundation; either
	12	* version 2.1 of the License, or (at your option) any later version.
	13	*
	14	* This library is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	17	* Lesser General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU Lesser General Public
	20	* License along with this library; if not, write to the Free Software
	21	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	22	*/
	23
	24	#ifndef _LTT_TRACER_H
	25	#define _LTT_TRACER_H
	26
	27	#include <sys/types.h>
	28	#include <stdarg.h>
	29	#include <ust/marker.h>
	30	#include <ust/marker-internal.h>
	31	#include <ust/probe-internal.h>
	32	#include <ust/core.h>
	33	#include <ust/compat.h>
	34	#include "channels.h"
	35	#include "tracercore.h"
	36	#include "tracerconst.h"
	37	#include "buffers.h"
	38
	39	/* Number of bytes to log with a read/write event */
	40	#define LTT_LOG_RW_SIZE 32L
	41
	42	/* Interval (in jiffies) at which the LTT per-CPU timer fires */
	43	#define LTT_PERCPU_TIMER_INTERVAL 1
	44
	45	#ifndef LTT_ARCH_TYPE
	46	#define LTT_ARCH_TYPE LTT_ARCH_TYPE_UNDEFINED
	47	#endif
	48
	49	#ifndef LTT_ARCH_VARIANT
	50	#define LTT_ARCH_VARIANT LTT_ARCH_VARIANT_NONE
	51	#endif
	52
	53	struct ltt_active_ust_marker;
	54
	55	/* Maximum number of callbacks per ust_marker */
	56	#define LTT_NR_CALLBACKS 10
	57
	58	struct ltt_serialize_closure;
	59	struct ltt_probe_private_data;
	60
	61	struct ltt_serialize_closure {
	62	ltt_serialize_cb *callbacks;
	63	long cb_args[LTT_NR_CALLBACKS];
	64	unsigned int cb_idx;
	65	};
	66
	67	extern size_t ltt_serialize_data(struct ust_buffer *buf, size_t buf_offset,
	68	struct ltt_serialize_closure *closure,
	69	void *serialize_private,
	70	unsigned int stack_pos_ctx, int *largest_align,
	71	const char fmt, va_list args);
	72
	73	struct ltt_probe_private_data {
	74	struct ust_trace trace; /
	75	* Target trace, for metadata
	76	* or statedump.
	77	*/
	78	ltt_serialize_cb serializer; /*
	79	* Serialization function override.
	80	*/
	81	void serialize_private; /
	82	* Private data for serialization
	83	* functions.
	84	*/
	85	};
	86
	87	enum ltt_channels {
	88	LTT_CHANNEL_METADATA,
	89	LTT_CHANNEL_UST,
	90	};
	91
	92	struct chan_info_struct {
	93	const char *name;
	94	unsigned int def_subbufsize;
	95	unsigned int def_subbufcount;
	96	};
	97
	98	struct ltt_active_ust_marker {
	99	struct cds_list_head node; /* active markers list */
	100	const char *channel;
	101	const char *name;
	102	const char *format;
	103	struct ltt_available_probe *probe;
	104	};
	105
	106	struct ust_marker; //ust//
	107	extern void ltt_vtrace(const struct ust_marker mdata, void probe_data,
	108	void call_data, const char fmt, va_list *args);
	109	extern void ltt_trace(const struct ust_marker mdata, void probe_data,
	110	void call_data, const char fmt, ...);
	111
	112	/*
	113	* Unique ID assigned to each registered probe.
	114	*/
	115	enum ust_marker_id {
	116	UST_MARKER_ID_SET_MARKER_ID = 0, /* Static IDs available (range 0-7) */
	117	UST_MARKER_ID_SET_MARKER_FORMAT,
	118	UST_MARKER_ID_COMPACT, /* Compact IDs (range: 8-127) */
	119	UST_MARKER_ID_DYNAMIC, /* Dynamic IDs (range: 128-65535) */
	120	};
	121
	122	/* static ids 0-1 reserved for internal use. */
	123	#define UST_MARKER_CORE_IDS 2
	124	static __inline__ enum ust_marker_id ust_marker_id_type(uint16_t id)
	125	{
	126	if (id < UST_MARKER_CORE_IDS)
	127	return (enum ust_marker_id)id;
	128	else
	129	return UST_MARKER_ID_DYNAMIC;
	130	}
	131
	132	struct user_dbg_data {
	133	unsigned long avail_size;
	134	unsigned long write;
	135	unsigned long read;
	136	};
	137
	138	struct ltt_trace_ops {
	139	/* First 32 bytes cache-hot cacheline */
	140	void (wakeup_channel) (struct ust_channel channel);
	141	int (user_blocking) (struct ust_trace trace,
	142	unsigned int index, size_t data_size,
	143	struct user_dbg_data *dbg);
	144	/* End of first 32 bytes cacheline */
	145	int (create_dirs) (struct ust_trace new_trace);
	146	void (remove_dirs) (struct ust_trace new_trace);
	147	int (create_channel) (const char trace_name,
	148	struct ust_trace *trace,
	149	const char *channel_name,
	150	struct ust_channel *channel,
	151	unsigned int subbuf_size,
	152	unsigned int n_subbufs, int overwrite);
	153	void (finish_channel) (struct ust_channel channel);
	154	void (remove_channel) (struct ust_channel channel);
	155	void (user_errors) (struct ust_trace trace,
	156	unsigned int index, size_t data_size,
	157	struct user_dbg_data *dbg, unsigned int cpu);
	158	};
	159
	160	struct ltt_transport {
	161	char *name;
	162	struct module *owner;
	163	struct cds_list_head node;
	164	struct ltt_trace_ops ops;
	165	};
	166
	167	enum trace_mode { LTT_TRACE_NORMAL, LTT_TRACE_FLIGHT, LTT_TRACE_HYBRID };
	168
	169	#define CHANNEL_FLAG_ENABLE (1U<<0)
	170	#define CHANNEL_FLAG_OVERWRITE (1U<<1)
	171
	172	/* Per-trace information - each trace/flight recorder represented by one */
	173	struct ust_trace {
	174	/* First 32 bytes cache-hot cacheline */
	175	struct cds_list_head list;
	176	struct ltt_trace_ops *ops;
	177	int active;
	178	/* Second 32 bytes cache-hot cacheline */
	179	struct ust_channel *channels;
	180	unsigned int nr_channels;
	181	u32 freq_scale;
	182	u64 start_freq;
	183	u64 start_tsc;
	184	unsigned long long start_monotonic;
	185	struct timeval start_time;
	186	struct ltt_channel_setting *settings;
	187	struct {
	188	struct dentry *trace_root;
	189	} dentry;
	190	struct urcu_ref urcu_ref; /* Each channel has a urcu_ref of the trace struct */
	191	struct ltt_transport *transport;
	192	struct urcu_ref ltt_transport_urcu_ref;
	193	char trace_name[NAME_MAX];
	194	} ____cacheline_aligned;
	195
	196	/*
	197	* We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
	198	* specifically with CPU frequency scaling someday, so using an interpolation
	199	* between the start and end of buffer values is not flexible enough. Using an
	200	* immediate frequency value permits to calculate directly the times for parts
	201	* of a buffer that would be before a frequency change.
	202	*
	203	* Keep the natural field alignment for _each field_ within this structure if
	204	* you ever add/remove a field from this header. Packed attribute is not used
	205	* because gcc generates poor code on at least powerpc and mips. Don't ever
	206	* let gcc add padding between the structure elements.
	207	*/
	208	struct ltt_subbuffer_header {
	209	uint64_t cycle_count_begin; /* Cycle count at subbuffer start */
	210	uint64_t cycle_count_end; /* Cycle count at subbuffer end */
	211	uint32_t magic_number; /*
	212	* Trace magic number.
	213	* contains endianness information.
	214	*/
	215	uint8_t major_version;
	216	uint8_t minor_version;
	217	uint8_t arch_size; /* Architecture pointer size */
	218	uint8_t alignment; /* LTT data alignment */
	219	uint64_t start_time_sec; /* NTP-corrected start time */
	220	uint64_t start_time_usec;
	221	uint64_t start_freq; /*
	222	* Frequency at trace start,
	223	* used all along the trace.
	224	*/
	225	uint32_t freq_scale; /* Frequency scaling (divisor) */
	226	uint32_t data_size; /* Size of data in subbuffer */
	227	uint32_t sb_size; /* Subbuffer size (including padding) */
	228	uint32_t events_lost; /*
	229	* Events lost in this subbuffer since
	230	* the beginning of the trace.
	231	* (may overflow)
	232	*/
	233	uint32_t subbuf_corrupt; /*
	234	* Corrupted (lost) subbuffers since
	235	* the begginig of the trace.
	236	* (may overflow)
	237	*/
	238	uint8_t header_end[0]; /* End of header */
	239	};
	240
	241	/**
	242	* ltt_subbuffer_header_size - called on buffer-switch to a new sub-buffer
	243	*
	244	* Return header size without padding after the structure. Don't use packed
	245	* structure because gcc generates inefficient code on some architectures
	246	* (powerpc, mips..)
	247	*/
	248	static __inline__ size_t ltt_subbuffer_header_size(void)
	249	{
	250	return offsetof(struct ltt_subbuffer_header, header_end);
	251	}
	252
	253	extern size_t ltt_write_event_header_slow(struct ust_channel *channel,
	254	struct ust_buffer *buf, long buf_offset,
	255	u16 eID, u32 event_size,
	256	u64 tsc, unsigned int rflags);
	257
	258
	259	/*
	260	* ltt_write_event_header
	261	*
	262	* Writes the event header to the offset (already aligned on 32-bits).
	263	*
	264	* @trace : trace to write to.
	265	* @channel : pointer to the channel structure..
	266	* @buf : buffer to write to.
	267	* @buf_offset : buffer offset to write to (aligned on 32 bits).
	268	* @eID : event ID
	269	* @event_size : size of the event, excluding the event header.
	270	* @tsc : time stamp counter.
	271	* @rflags : reservation flags.
	272	*
	273	* returns : offset where the event data must be written.
	274	*/
	275	static __inline__ size_t ltt_write_event_header(struct ust_channel *chan,
	276	struct ust_buffer *buf, long buf_offset,
	277	u16 eID, u32 event_size,
	278	u64 tsc, unsigned int rflags)
	279	{
	280	struct ltt_event_header header;
	281
	282	if (unlikely(rflags))
	283	goto slow_path;
	284
	285	header.id_time = eID << LTT_TSC_BITS;
	286	header.id_time \|= (u32)tsc & LTT_TSC_MASK;
	287	ust_buffers_write(buf, buf_offset, &header, sizeof(header));
	288	buf_offset += sizeof(header);
	289
	290	return buf_offset;
	291
	292	slow_path:
	293	return ltt_write_event_header_slow(chan, buf, buf_offset,
	294	eID, event_size, tsc, rflags);
	295	}
	296
	297	/*
	298	* Control channels :
	299	* control/metadata
	300	* control/interrupts
	301	* control/...
	302	*
	303	* cpu channel :
	304	* cpu
	305	*/
	306
	307	#define LTT_METADATA_CHANNEL "metadata_state"
	308	#define LTT_UST_CHANNEL "ust"
	309
	310	#define LTT_FLIGHT_PREFIX "flight-"
	311
	312	/* Tracer properties */
	313	//#define LTT_DEFAULT_SUBBUF_SIZE_LOW 134217728
	314	#define LTT_DEFAULT_SUBBUF_SIZE_LOW 65536
	315	//#define LTT_DEFAULT_SUBBUF_SIZE_LOW 4096
	316	#define LTT_DEFAULT_N_SUBBUFS_LOW 2
	317	//#define LTT_DEFAULT_SUBBUF_SIZE_MED 134217728
	318	#define LTT_DEFAULT_SUBBUF_SIZE_MED 262144
	319	//#define LTT_DEFAULT_SUBBUF_SIZE_MED 4096
	320	#define LTT_DEFAULT_N_SUBBUFS_MED 2
	321	//#define LTT_DEFAULT_SUBBUF_SIZE_HIGH 134217728
	322	#define LTT_DEFAULT_SUBBUF_SIZE_HIGH 1048576
	323	//#define LTT_DEFAULT_SUBBUF_SIZE_HIGH 4096
	324	#define LTT_DEFAULT_N_SUBBUFS_HIGH 2
	325	#define LTT_TRACER_MAGIC_NUMBER 0x00D6B7ED
	326	#define LTT_TRACER_VERSION_MAJOR 2
	327	#define LTT_TRACER_VERSION_MINOR 6
	328
	329	/**
	330	* ust_write_trace_header - Write trace header
	331	* @trace: Trace information
	332	* @header: Memory address where the information must be written to
	333	*/
	334	static __inline__ void ltt_write_trace_header(struct ust_trace *trace,
	335	struct ltt_subbuffer_header *header)
	336	{
	337	header->magic_number = LTT_TRACER_MAGIC_NUMBER;
	338	header->major_version = LTT_TRACER_VERSION_MAJOR;
	339	header->minor_version = LTT_TRACER_VERSION_MINOR;
	340	header->arch_size = sizeof(void *);
	341	header->alignment = ltt_get_alignment();
	342	header->start_time_sec = trace->start_time.tv_sec;
	343	header->start_time_usec = trace->start_time.tv_usec;
	344	header->start_freq = trace->start_freq;
	345	header->freq_scale = trace->freq_scale;
	346	}
	347
	348	#ifndef UST_VALGRIND
	349
	350	static __inline__ int ust_get_cpu(void)
	351	{
	352	int cpu;
	353
	354	cpu = sched_getcpu();
	355	if (likely(cpu >= 0))
	356	return cpu;
	357	/*
	358	* If getcpu(2) is not implemented in the Kernel use CPU 0 as fallback.
	359	*/
	360	return 0;
	361	}
	362
	363	#else /* #else #ifndef UST_VALGRIND */
	364
	365	static __inline__ int ust_get_cpu(void)
	366	{
	367	/*
	368	* Valgrind does not support the sched_getcpu() vsyscall.
	369	* It causes it to detect a segfault in the program and stop it.
	370	* So if we want to check libust with valgrind, we have to refrain
	371	* from using this call. TODO: it would probably be better to return
	372	* other values too, to better test it.
	373	*/
	374	return 0;
	375	}
	376
	377	#endif /* #else #ifndef UST_VALGRIND */
	378
	379	/*
	380	* Size reserved for high priority events (interrupts, NMI, BH) at the end of a
	381	* nearly full buffer. User space won't use this last amount of space when in
	382	* blocking mode. This space also includes the event header that would be
	383	* written by this user space event.
	384	*/
	385	#define LTT_RESERVE_CRITICAL 4096
	386
	387	/* Register and unregister function pointers */
	388
	389	enum ltt_module_function {
	390	LTT_FUNCTION_RUN_FILTER,
	391	LTT_FUNCTION_FILTER_CONTROL,
	392	LTT_FUNCTION_STATEDUMP
	393	};
	394
	395	extern void ltt_transport_register(struct ltt_transport *transport);
	396	extern void ltt_transport_unregister(struct ltt_transport *transport);
	397
	398	/* Exported control function */
	399
	400	union ltt_control_args {
	401	struct {
	402	enum trace_mode mode;
	403	unsigned int subbuf_size_low;
	404	unsigned int n_subbufs_low;
	405	unsigned int subbuf_size_med;
	406	unsigned int n_subbufs_med;
	407	unsigned int subbuf_size_high;
	408	unsigned int n_subbufs_high;
	409	} new_trace;
	410	};
	411
	412	extern int _ltt_trace_setup(const char *trace_name);
	413	extern int ltt_trace_setup(const char *trace_name);
	414	extern struct ust_trace _ltt_trace_find_setup(const char trace_name);
	415	extern int ltt_trace_set_type(const char trace_name, const char trace_type);
	416	extern int ltt_trace_set_channel_subbufsize(const char *trace_name,
	417	const char *channel_name, unsigned int size);
	418	extern int ltt_trace_set_channel_subbufcount(const char *trace_name,
	419	const char *channel_name, unsigned int cnt);
	420	extern int ltt_trace_set_channel_enable(const char *trace_name,
	421	const char *channel_name, unsigned int enable);
	422	extern int ltt_trace_set_channel_overwrite(const char *trace_name,
	423	const char *channel_name, unsigned int overwrite);
	424	extern int ltt_trace_alloc(const char *trace_name);
	425	extern int ltt_trace_destroy(const char *trace_name, int drop);
	426	extern int ltt_trace_start(const char *trace_name);
	427	extern int ltt_trace_stop(const char *trace_name);
	428
	429	enum ltt_filter_control_msg {
	430	LTT_FILTER_DEFAULT_ACCEPT,
	431	LTT_FILTER_DEFAULT_REJECT
	432	};
	433
	434	extern int ltt_filter_control(enum ltt_filter_control_msg msg,
	435	const char *trace_name);
	436
	437	extern struct dentry *get_filter_root(void);
	438
	439	extern void ltt_write_trace_header(struct ust_trace *trace,
	440	struct ltt_subbuffer_header *header);
	441	extern void ltt_buffer_destroy(struct ust_channel *ltt_chan);
	442
	443	extern void ltt_core_register(int (function)(u8, void ));
	444
	445	extern void ltt_core_unregister(void);
	446
	447	extern void ltt_release_trace(struct urcu_ref *urcu_ref);
	448	extern void ltt_release_transport(struct urcu_ref *urcu_ref);
	449
	450	extern void ltt_dump_ust_marker_state(struct ust_trace *trace);
	451
	452	extern void ltt_lock_traces(void);
	453	extern void ltt_unlock_traces(void);
	454
	455	extern struct ust_trace _ltt_trace_find(const char trace_name);
	456
	457	#endif /* _LTT_TRACER_H */