[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 <linux/trace-clock.h>
#include <asm/atomic.h>
#include <asm/local.h>

#include "ltt-tracer-core.h"
#include "ltt-events.h"

/* 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,
};

#if 0
size_t ltt_serialize_printf(struct lib_ring_buffer *buf, unsigned long buf_offset,
			    size_t *msg_size, char *output, size_t outlen,
			    const char *fmt);

/*
 * Unique ID assigned to each registered probe.
 */
enum marker_id {
	MARKER_ID_SET_MARKER_ID = 0,	/* Static IDs available (range 0-7) */
	MARKER_ID_SET_MARKER_FORMAT,
	MARKER_ID_COMPACT,		/* Compact IDs (range: 8-127)	    */
	MARKER_ID_DYNAMIC,		/* Dynamic IDs (range: 128-65535)   */
};

/* static ids 0-1 reserved for internal use. */
#define MARKER_CORE_IDS		2
static __inline__ enum marker_id marker_id_type(uint16_t id)
{
	if (id < MARKER_CORE_IDS)
		return (enum marker_id)id;
	else
		return MARKER_ID_DYNAMIC;
}

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

enum trace_mode { LTT_TRACE_NORMAL, LTT_TRACE_FLIGHT, LTT_TRACE_HYBRID };

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

#if 0
/* Per-trace information - each trace/flight recorder represented by one */
struct ltt_trace {
	/* First 32 bytes cache-hot cacheline */
	struct list_head list;
	struct ltt_chan **channels;
	unsigned int nr_channels;
	int active;
	/* Second 32 bytes cache-hot cacheline */
	struct ltt_trace_ops *ops;
	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;
		struct dentry			*ascii_root;
	} dentry;
	struct kref kref; /* Each channel has a kref of the trace struct */
	struct ltt_transport *transport;
	struct kref ltt_transport_kref;
	wait_queue_head_t kref_wq; /* Place for ltt_trace_destroy to sleep */
	char trace_name[NAME_MAX];
} ____cacheline_aligned;
#endif //0

/*
 * 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

/*
 * 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 */
};

static inline notrace u64 lib_ring_buffer_clock_read(struct channel *chan)
{
	return trace_clock_read64();
}

/*
 * record_header_size - Calculate the header size and padding necessary.
 * @config: ring buffer instance configuration
 * @chan: channel
 * @offset: offset in the write buffer
 * @data_size: size of the payload
 * @pre_header_padding: padding to add before the header (output)
 * @rflags: reservation flags
 * @ctx: reservation context
 *
 * Returns the event header size (including padding).
 *
 * Important note :
 * The event header must be 32-bits. The total offset calculated here :
 *
 * Alignment of header struct on 32 bits (min arch size, header size)
 * + sizeof(header struct)  (32-bits)
 * + (opt) u16 (ext. event id)
 * + (opt) u16 (event_size)
 *             (if event_size == LTT_MAX_SMALL_SIZE, has ext. event size)
 * + (opt) u32 (ext. event size)
 * + (opt) u64 full TSC (aligned on min(64-bits, arch size))
 *
 * The payload must itself determine its own alignment from the biggest type it
 * contains.
 */
static __inline__
unsigned char record_header_size(const struct lib_ring_buffer_config *config,
				 struct channel *chan, size_t offset,
				 size_t data_size, size_t *pre_header_padding,
				 unsigned int rflags,
				 struct lib_ring_buffer_ctx *ctx)
{
	size_t orig_offset = offset;
	size_t padding;

	BUILD_BUG_ON(sizeof(struct event_header) != sizeof(u32));

	padding = lib_ring_buffer_align(offset,
					sizeof(struct event_header));
	offset += padding;
	offset += sizeof(struct event_header);

	if (unlikely(rflags)) {
		switch (rflags) {
		case LTT_RFLAG_ID_SIZE_TSC:
			offset += sizeof(u16) + sizeof(u16);
			if (data_size >= LTT_MAX_SMALL_SIZE)
				offset += sizeof(u32);
			offset += ltt_align(offset, sizeof(u64));
			offset += sizeof(u64);
			break;
		case LTT_RFLAG_ID_SIZE:
			offset += sizeof(u16) + sizeof(u16);
			if (data_size >= LTT_MAX_SMALL_SIZE)
				offset += sizeof(u32);
			break;
		case LTT_RFLAG_ID:
			offset += sizeof(u16);
			break;
		}
	}

	*pre_header_padding = padding;
	return offset - orig_offset;
}

#include <linux/ringbuffer/api.h>

extern
void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
				 struct lib_ring_buffer_ctx *ctx,
				 u16 eID, u32 event_size);

/*
 * ltt_write_event_header
 *
 * Writes the event header to the offset (already aligned on 32-bits).
 *
 * @config: ring buffer instance configuration
 * @ctx: reservation context
 * @eID : event ID
 * @event_size : size of the event, excluding the event header.
 */
static __inline__
void ltt_write_event_header(const struct lib_ring_buffer_config *config,
			    struct lib_ring_buffer_ctx *ctx,
			    u16 eID, u32 event_size)
{
	struct event_header header;

	if (unlikely(ctx->rflags))
		goto slow_path;

	header.id_time = eID << LTT_TSC_BITS;
	header.id_time |= (u32)ctx->tsc & LTT_TSC_MASK;
	lib_ring_buffer_write(config, ctx, &header, sizeof(header));

slow_path:
	ltt_write_event_header_slow(config, ctx, eID, event_size);
}

#if 0
/*
 * ltt_read_event_header
 * buf_offset must aligned on 32 bits
 */
static __inline__
size_t ltt_read_event_header(struct ltt_chanbuf_alloc *bufa, long buf_offset,
			     u64 *tsc, u32 *event_size, u16 *eID,
			     unsigned int *rflags)
{
	struct ltt_event_header header;
	u16 small_size;

	ltt_relay_read(bufa, buf_offset, &header, sizeof(header));
	buf_offset += sizeof(header);

	*event_size = INT_MAX;
	*eID = header.id_time >> LTT_TSC_BITS;
	*tsc = header.id_time & LTT_TSC_MASK;

	switch (*eID) {
	case 29:
		*rflags = LTT_RFLAG_ID_SIZE_TSC;
		ltt_relay_read(bufa, buf_offset, eID, sizeof(u16));
		buf_offset += sizeof(u16);
		ltt_relay_read(bufa, buf_offset, &small_size, sizeof(u16));
		buf_offset += sizeof(u16);
		if (small_size == LTT_MAX_SMALL_SIZE) {
			ltt_relay_read(bufa, buf_offset, event_size,
					sizeof(u32));
			buf_offset += sizeof(u32);
		} else
			*event_size = small_size;
		buf_offset += ltt_align(buf_offset, sizeof(u64));
		ltt_relay_read(bufa, buf_offset, tsc, sizeof(u64));
		buf_offset += sizeof(u64);
		break;
	case 30:
		*rflags = LTT_RFLAG_ID_SIZE;
		ltt_relay_read(bufa, buf_offset, eID, sizeof(u16));
		buf_offset += sizeof(u16);
		ltt_relay_read(bufa, buf_offset, &small_size, sizeof(u16));
		buf_offset += sizeof(u16);
		if (small_size == LTT_MAX_SMALL_SIZE) {
			ltt_relay_read(bufa, buf_offset, event_size,
					sizeof(u32));
			buf_offset += sizeof(u32);
		} else
			*event_size = small_size;
		break;
	case 31:
		*rflags = LTT_RFLAG_ID;
		ltt_relay_read(bufa, buf_offset, eID, sizeof(u16));
		buf_offset += sizeof(u16);
		break;
	default:
		*rflags = 0;
		break;
	}

	return buf_offset;
}
#endif //0

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

/**
 * ltt_write_trace_header - Write trace header
 * @priv: Private data (struct trace)
 * @header: Memory address where the information must be written to
 */
static __inline__
void write_trace_header(const struct lib_ring_buffer_config *config,
			struct packet_header *header)
{
	header->magic = CTF_MAGIC_NUMBER;
#if 0
	/* TODO: move start time to metadata */
	header->major_version = LTT_TRACER_VERSION_MAJOR;
	header->minor_version = LTT_TRACER_VERSION_MINOR;
	header->arch_size = sizeof(void *);
	header->alignment = lib_ring_buffer_get_alignment(config);
	header->start_time_sec = ltt_chan->session->start_time.tv_sec;
	header->start_time_usec = ltt_chan->session->start_time.tv_usec;
	header->start_freq = ltt_chan->session->start_freq;
	header->freq_scale = ltt_chan->session->freq_scale;
#endif //0
}

/*
 * 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	19	#include <linux/trace-clock.h>
1c8284eb MD	20	#include <asm/atomic.h>
	21	#include <asm/local.h>
	22
	23	#include "ltt-tracer-core.h"
1c25284c	24	#include "ltt-events.h"
1c8284eb MD	25
	26	/* Number of bytes to log with a read/write event */
	27	#define LTT_LOG_RW_SIZE 32L
	28
1c8284eb MD	29	/* Maximum number of callbacks per marker */
	30	#define LTT_NR_CALLBACKS 10
	31
11b5a3c2 MD	32	struct ltt_serialize_closure;
	33
	34	/* Serialization callback */
	35	typedef size_t (ltt_serialize_cb)(struct lib_ring_buffer buf,
	36	size_t buf_offset,
	37	struct ltt_serialize_closure *closure,
	38	void *serialize_private,
	39	unsigned int stack_pos_ctx,
	40	int *largest_align,
	41	const char fmt, va_list args);
	42
1c8284eb MD	43	struct ltt_serialize_closure {
	44	ltt_serialize_cb *callbacks;
	45	long cb_args[LTT_NR_CALLBACKS];
	46	unsigned int cb_idx;
	47	};
	48
11b5a3c2	49	size_t ltt_serialize_data(struct lib_ring_buffer *buf, size_t buf_offset,
1c8284eb MD	50	struct ltt_serialize_closure *closure,
	51	void *serialize_private, unsigned int stack_pos_ctx,
	52	int largest_align, const char fmt, va_list *args);
	53
1c8284eb MD	54	enum ltt_channels {
	55	LTT_CHANNEL_METADATA,
	56	LTT_CHANNEL_FD_STATE,
	57	LTT_CHANNEL_GLOBAL_STATE,
	58	LTT_CHANNEL_IRQ_STATE,
	59	LTT_CHANNEL_MODULE_STATE,
	60	LTT_CHANNEL_NETIF_STATE,
	61	LTT_CHANNEL_SOFTIRQ_STATE,
	62	LTT_CHANNEL_SWAP_STATE,
	63	LTT_CHANNEL_SYSCALL_STATE,
	64	LTT_CHANNEL_TASK_STATE,
	65	LTT_CHANNEL_VM_STATE,
	66	LTT_CHANNEL_FS,
	67	LTT_CHANNEL_INPUT,
	68	LTT_CHANNEL_IPC,
	69	LTT_CHANNEL_KERNEL,
	70	LTT_CHANNEL_MM,
	71	LTT_CHANNEL_RCU,
	72	LTT_CHANNEL_DEFAULT,
	73	};
	74
11b5a3c2 MD	75	#if 0
11b5a3c2 MD	76	size_t ltt_serialize_printf(struct lib_ring_buffer *buf, unsigned long buf_offset,
1c8284eb MD	77	size_t msg_size, char output, size_t outlen,
	78	const char *fmt);
	79
	80	/*
	81	* Unique ID assigned to each registered probe.
	82	*/
	83	enum marker_id {
	84	MARKER_ID_SET_MARKER_ID = 0, /* Static IDs available (range 0-7) */
	85	MARKER_ID_SET_MARKER_FORMAT,
	86	MARKER_ID_COMPACT, /* Compact IDs (range: 8-127) */
	87	MARKER_ID_DYNAMIC, /* Dynamic IDs (range: 128-65535) */
	88	};
	89
	90	/* static ids 0-1 reserved for internal use. */
	91	#define MARKER_CORE_IDS 2
	92	static __inline__ enum marker_id marker_id_type(uint16_t id)
	93	{
	94	if (id < MARKER_CORE_IDS)
	95	return (enum marker_id)id;
	96	else
	97	return MARKER_ID_DYNAMIC;
	98	}
	99
	100	struct user_dbg_data {
	101	unsigned long avail_size;
	102	unsigned long write;
	103	unsigned long read;
	104	};
	105
1c8284eb MD	106	enum trace_mode { LTT_TRACE_NORMAL, LTT_TRACE_FLIGHT, LTT_TRACE_HYBRID };
	107
	108	#define CHANNEL_FLAG_ENABLE (1U<<0)
	109	#define CHANNEL_FLAG_OVERWRITE (1U<<1)
11b5a3c2	110	#endif //0
1c8284eb	111
c0e31d2e	112	#if 0
1c8284eb MD	113	/* Per-trace information - each trace/flight recorder represented by one */
	114	struct ltt_trace {
	115	/* First 32 bytes cache-hot cacheline */
	116	struct list_head list;
7514523f	117	struct ltt_chan **channels;
1c8284eb MD	118	unsigned int nr_channels;
	119	int active;
	120	/* Second 32 bytes cache-hot cacheline */
	121	struct ltt_trace_ops *ops;
	122	u32 freq_scale;
	123	u64 start_freq;
	124	u64 start_tsc;
	125	unsigned long long start_monotonic;
	126	struct timeval start_time;
	127	struct ltt_channel_setting *settings;
	128	struct {
	129	struct dentry *trace_root;
	130	struct dentry *ascii_root;
	131	} dentry;
	132	struct kref kref; /* Each channel has a kref of the trace struct */
	133	struct ltt_transport *transport;
	134	struct kref ltt_transport_kref;
	135	wait_queue_head_t kref_wq; /* Place for ltt_trace_destroy to sleep */
	136	char trace_name[NAME_MAX];
	137	} ____cacheline_aligned;
c0e31d2e	138	#endif //0
1c8284eb	139
7514523f MD	140	/*
7514523f MD	141	* Hardcoded event headers
1c8284eb MD	142	*
	143	* event header for a trace with active heartbeat : 27 bits timestamps
	144	*
	145	* headers are 32-bits aligned. In order to insure such alignment, a dynamic per
	146	* trace alignment value must be done.
	147	*
	148	* Remember that the C compiler does align each member on the boundary
	149	* equivalent to their own size.
	150	*
	151	* As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
	152	* bytes aligned, so the buffer header and trace header are aligned.
	153	*
	154	* Event headers are aligned depending on the trace alignment option.
	155	*
	156	* Note using C structure bitfields for cross-endianness and portability
	157	* concerns.
	158	*/
	159
	160	#define LTT_RESERVED_EVENTS 3
	161	#define LTT_EVENT_BITS 5
	162	#define LTT_FREE_EVENTS ((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
	163	#define LTT_TSC_BITS 27
	164	#define LTT_TSC_MASK ((1 << LTT_TSC_BITS) - 1)
	165
7514523f	166	struct event_header {
1c8284eb MD	167	u32 id_time; /* 5 bits event id (MSB); 27 bits time (LSB) */
	168	};
	169
	170	/* Reservation flags */
	171	#define LTT_RFLAG_ID (1 << 0)
	172	#define LTT_RFLAG_ID_SIZE (1 << 1)
	173	#define LTT_RFLAG_ID_SIZE_TSC (1 << 2)
	174
	175	#define LTT_MAX_SMALL_SIZE 0xFFFFU
	176
	177	/*
	178	* We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
	179	* specifically with CPU frequency scaling someday, so using an interpolation
	180	* between the start and end of buffer values is not flexible enough. Using an
	181	* immediate frequency value permits to calculate directly the times for parts
	182	* of a buffer that would be before a frequency change.
	183	*
	184	* Keep the natural field alignment for _each field_ within this structure if
	185	* you ever add/remove a field from this header. Packed attribute is not used
	186	* because gcc generates poor code on at least powerpc and mips. Don't ever
	187	* let gcc add padding between the structure elements.
	188	*/
1c25284c MD	189	struct packet_header {
1c25284c MD	190	uint32_t magic; /*
1c8284eb MD	191	* Trace magic number.
	192	* contains endianness information.
	193	*/
1c25284c MD	194	uint8_t trace_uuid[16];
	195	uint32_t stream_id;
	196	uint64_t timestamp_begin; /* Cycle count at subbuffer start */
	197	uint64_t timestamp_end; /* Cycle count at subbuffer end */
	198	uint32_t content_size; /* Size of data in subbuffer */
	199	uint32_t packet_size; /* Subbuffer size (include padding) */
	200	uint32_t events_lost; /*
	201	* Events lost in this subbuffer since
	202	* the beginning of the trace.
	203	* (may overflow)
	204	*/
	205	/* TODO: move to metadata */
	206	#if 0
1c8284eb MD	207	uint8_t major_version;
	208	uint8_t minor_version;
	209	uint8_t arch_size; /* Architecture pointer size */
	210	uint8_t alignment; /* LTT data alignment */
	211	uint64_t start_time_sec; /* NTP-corrected start time */
	212	uint64_t start_time_usec;
	213	uint64_t start_freq; /*
	214	* Frequency at trace start,
	215	* used all along the trace.
	216	*/
	217	uint32_t freq_scale; /* Frequency scaling (divisor) */
1c25284c	218	#endif //0
1c8284eb MD	219	uint8_t header_end[0]; /* End of header */
	220	};
	221
7514523f	222	static inline notrace u64 lib_ring_buffer_clock_read(struct channel *chan)
1c8284eb	223	{
7514523f	224	return trace_clock_read64();
1c8284eb MD	225	}
	226
	227	/*
7514523f MD	228	* record_header_size - Calculate the header size and padding necessary.
	229	* @config: ring buffer instance configuration
	230	* @chan: channel
	231	* @offset: offset in the write buffer
	232	* @data_size: size of the payload
	233	* @pre_header_padding: padding to add before the header (output)
	234	* @rflags: reservation flags
	235	* @ctx: reservation context
1c8284eb	236	*
7514523f	237	* Returns the event header size (including padding).
1c8284eb MD	238	*
	239	* Important note :
	240	* The event header must be 32-bits. The total offset calculated here :
	241	*
	242	* Alignment of header struct on 32 bits (min arch size, header size)
	243	* + sizeof(header struct) (32-bits)
	244	* + (opt) u16 (ext. event id)
	245	* + (opt) u16 (event_size)
	246	* (if event_size == LTT_MAX_SMALL_SIZE, has ext. event size)
	247	* + (opt) u32 (ext. event size)
	248	* + (opt) u64 full TSC (aligned on min(64-bits, arch size))
	249	*
	250	* The payload must itself determine its own alignment from the biggest type it
	251	* contains.
7514523f	252	*/
1c8284eb	253	static __inline__
7514523f MD	254	unsigned char record_header_size(const struct lib_ring_buffer_config *config,
	255	struct channel *chan, size_t offset,
	256	size_t data_size, size_t *pre_header_padding,
	257	unsigned int rflags,
	258	struct lib_ring_buffer_ctx *ctx)
1c8284eb MD	259	{
	260	size_t orig_offset = offset;
	261	size_t padding;
	262
7514523f	263	BUILD_BUG_ON(sizeof(struct event_header) != sizeof(u32));
1c8284eb	264
6db3d13b	265	padding = lib_ring_buffer_align(offset,
7514523f	266	sizeof(struct event_header));
1c8284eb	267	offset += padding;
7514523f	268	offset += sizeof(struct event_header);
1c8284eb MD	269
	270	if (unlikely(rflags)) {
	271	switch (rflags) {
	272	case LTT_RFLAG_ID_SIZE_TSC:
	273	offset += sizeof(u16) + sizeof(u16);
	274	if (data_size >= LTT_MAX_SMALL_SIZE)
	275	offset += sizeof(u32);
	276	offset += ltt_align(offset, sizeof(u64));
	277	offset += sizeof(u64);
	278	break;
	279	case LTT_RFLAG_ID_SIZE:
	280	offset += sizeof(u16) + sizeof(u16);
	281	if (data_size >= LTT_MAX_SMALL_SIZE)
	282	offset += sizeof(u32);
	283	break;
	284	case LTT_RFLAG_ID:
	285	offset += sizeof(u16);
	286	break;
	287	}
	288	}
	289
7514523f	290	*pre_header_padding = padding;
1c8284eb MD	291	return offset - orig_offset;
	292	}
	293
7514523f MD	294	#include <linux/ringbuffer/api.h>
7514523f MD	295
1c8284eb	296	extern
1c25284c MD	297	void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
	298	struct lib_ring_buffer_ctx *ctx,
	299	u16 eID, u32 event_size);
1c8284eb MD	300
	301	/*
	302	* ltt_write_event_header
	303	*
	304	* Writes the event header to the offset (already aligned on 32-bits).
	305	*
7514523f MD	306	* @config: ring buffer instance configuration
7514523f MD	307	* @ctx: reservation context
1c8284eb MD	308	* @eID : event ID
1c8284eb MD	309	* @event_size : size of the event, excluding the event header.
1c8284eb MD	310	*/
1c8284eb MD	311	static __inline__
7514523f MD	312	void ltt_write_event_header(const struct lib_ring_buffer_config *config,
	313	struct lib_ring_buffer_ctx *ctx,
	314	u16 eID, u32 event_size)
1c8284eb	315	{
7514523f	316	struct event_header header;
1c8284eb	317
7514523f	318	if (unlikely(ctx->rflags))
1c8284eb MD	319	goto slow_path;
	320
	321	header.id_time = eID << LTT_TSC_BITS;
7514523f MD	322	header.id_time \|= (u32)ctx->tsc & LTT_TSC_MASK;
7514523f MD	323	lib_ring_buffer_write(config, ctx, &header, sizeof(header));
1c8284eb MD	324
1c8284eb MD	325	slow_path:
7514523f	326	ltt_write_event_header_slow(config, ctx, eID, event_size);
1c8284eb MD	327	}
1c8284eb MD	328
7514523f	329	#if 0
1c8284eb MD	330	/*
	331	* ltt_read_event_header
	332	* buf_offset must aligned on 32 bits
	333	*/
	334	static __inline__
	335	size_t ltt_read_event_header(struct ltt_chanbuf_alloc *bufa, long buf_offset,
	336	u64 tsc, u32 event_size, u16 *eID,
	337	unsigned int *rflags)
	338	{
	339	struct ltt_event_header header;
	340	u16 small_size;
	341
	342	ltt_relay_read(bufa, buf_offset, &header, sizeof(header));
	343	buf_offset += sizeof(header);
	344
	345	*event_size = INT_MAX;
	346	*eID = header.id_time >> LTT_TSC_BITS;
	347	*tsc = header.id_time & LTT_TSC_MASK;
	348
	349	switch (*eID) {
	350	case 29:
	351	*rflags = LTT_RFLAG_ID_SIZE_TSC;
	352	ltt_relay_read(bufa, buf_offset, eID, sizeof(u16));
	353	buf_offset += sizeof(u16);
	354	ltt_relay_read(bufa, buf_offset, &small_size, sizeof(u16));
	355	buf_offset += sizeof(u16);
	356	if (small_size == LTT_MAX_SMALL_SIZE) {
	357	ltt_relay_read(bufa, buf_offset, event_size,
	358	sizeof(u32));
	359	buf_offset += sizeof(u32);
	360	} else
	361	*event_size = small_size;
	362	buf_offset += ltt_align(buf_offset, sizeof(u64));
	363	ltt_relay_read(bufa, buf_offset, tsc, sizeof(u64));
	364	buf_offset += sizeof(u64);
	365	break;
	366	case 30:
	367	*rflags = LTT_RFLAG_ID_SIZE;
	368	ltt_relay_read(bufa, buf_offset, eID, sizeof(u16));
	369	buf_offset += sizeof(u16);
	370	ltt_relay_read(bufa, buf_offset, &small_size, sizeof(u16));
	371	buf_offset += sizeof(u16);
	372	if (small_size == LTT_MAX_SMALL_SIZE) {
	373	ltt_relay_read(bufa, buf_offset, event_size,
	374	sizeof(u32));
	375	buf_offset += sizeof(u32);
	376	} else
	377	*event_size = small_size;
	378	break;
	379	case 31:
	380	*rflags = LTT_RFLAG_ID;
	381	ltt_relay_read(bufa, buf_offset, eID, sizeof(u16));
	382	buf_offset += sizeof(u16);
	383	break;
	384	default:
	385	*rflags = 0;
	386	break;
	387	}
	388
	389	return buf_offset;
	390	}
7514523f	391	#endif //0
1c8284eb	392
1c8284eb	393	/* Tracer properties */
1c25284c MD	394	#define CTF_MAGIC_NUMBER 0xC1FC1FC1
	395	#define LTT_TRACER_VERSION_MAJOR 3
	396	#define LTT_TRACER_VERSION_MINOR 0
1c8284eb MD	397
	398	/**
	399	* ltt_write_trace_header - Write trace header
7514523f	400	* @priv: Private data (struct trace)
1c8284eb MD	401	* @header: Memory address where the information must be written to
	402	*/
	403	static __inline__
1c25284c MD	404	void write_trace_header(const struct lib_ring_buffer_config *config,
1c25284c MD	405	struct packet_header *header)
1c8284eb	406	{
1c25284c MD	407	header->magic = CTF_MAGIC_NUMBER;
	408	#if 0
	409	/* TODO: move start time to metadata */
1c8284eb MD	410	header->major_version = LTT_TRACER_VERSION_MAJOR;
	411	header->minor_version = LTT_TRACER_VERSION_MINOR;
	412	header->arch_size = sizeof(void *);
1c25284c MD	413	header->alignment = lib_ring_buffer_get_alignment(config);
	414	header->start_time_sec = ltt_chan->session->start_time.tv_sec;
	415	header->start_time_usec = ltt_chan->session->start_time.tv_usec;
	416	header->start_freq = ltt_chan->session->start_freq;
	417	header->freq_scale = ltt_chan->session->freq_scale;
	418	#endif //0
1c8284eb MD	419	}
	420
	421	/*
	422	* Size reserved for high priority events (interrupts, NMI, BH) at the end of a
	423	* nearly full buffer. User space won't use this last amount of space when in
	424	* blocking mode. This space also includes the event header that would be
	425	* written by this user space event.
	426	*/
	427	#define LTT_RESERVE_CRITICAL 4096
	428
	429	/* Register and unregister function pointers */
	430
	431	enum ltt_module_function {
	432	LTT_FUNCTION_RUN_FILTER,
	433	LTT_FUNCTION_FILTER_CONTROL,
	434	LTT_FUNCTION_STATEDUMP
	435	};
	436
	437	extern int ltt_module_register(enum ltt_module_function name, void *function,
	438	struct module *owner);
	439	extern void ltt_module_unregister(enum ltt_module_function name);
	440
1c8284eb MD	441	/* Exported control function */
1c8284eb MD	442
1c8284eb MD	443	void ltt_core_register(int (function)(u8, void ));
	444
	445	void ltt_core_unregister(void);
	446
1c8284eb MD	447	extern
	448	void ltt_statedump_register_kprobes_dump(void (callback)(void call_data));
	449	extern
	450	void ltt_statedump_unregister_kprobes_dump(void (callback)(void call_data));
	451
	452	extern void ltt_dump_softirq_vec(void *call_data);
	453
f277b4c1	454	#ifdef CONFIG_HAVE_LTT_DUMP_TABLES
1c8284eb MD	455	extern void ltt_dump_sys_call_table(void *call_data);
1c8284eb MD	456	extern void ltt_dump_idt_table(void *call_data);
f277b4c1 MD	457	#else
	458	static inline void ltt_dump_sys_call_table(void *call_data)
	459	{
	460	}
	461
	462	static inline void ltt_dump_idt_table(void *call_data)
	463	{
	464	}
	465	#endif
1c8284eb	466
1c8284eb	467	#endif /* _LTT_TRACER_H */