[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

#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
/* Align data on its natural alignment */
#define RING_BUFFER_ALIGN
#endif

#include <linux/ringbuffer/config.h>

#include <stdarg.h>
#include <linux/types.h>
#include <linux/limits.h>
#include <linux/list.h>
#include <linux/cache.h>
#include <linux/kernel.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(config, 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
7514523f MD	12	#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
	13	/* Align data on its natural alignment */
	14	#define RING_BUFFER_ALIGN
	15	#endif
	16
	17	#include <linux/ringbuffer/config.h>
	18
1c8284eb MD	19	#include <stdarg.h>
	20	#include <linux/types.h>
	21	#include <linux/limits.h>
	22	#include <linux/list.h>
	23	#include <linux/cache.h>
	24	#include <linux/kernel.h>
	25	#include <linux/timex.h>
	26	#include <linux/wait.h>
1c8284eb	27	#include <linux/trace-clock.h>
1c8284eb MD	28	#include <asm/atomic.h>
	29	#include <asm/local.h>
	30
	31	#include "ltt-tracer-core.h"
1c25284c	32	#include "ltt-events.h"
1c8284eb MD	33
	34	/* Number of bytes to log with a read/write event */
	35	#define LTT_LOG_RW_SIZE 32L
	36
1c8284eb MD	37	/* Maximum number of callbacks per marker */
	38	#define LTT_NR_CALLBACKS 10
	39
11b5a3c2 MD	40	struct ltt_serialize_closure;
	41
	42	/* Serialization callback */
	43	typedef size_t (ltt_serialize_cb)(struct lib_ring_buffer buf,
	44	size_t buf_offset,
	45	struct ltt_serialize_closure *closure,
	46	void *serialize_private,
	47	unsigned int stack_pos_ctx,
	48	int *largest_align,
	49	const char fmt, va_list args);
	50
1c8284eb MD	51	struct ltt_serialize_closure {
	52	ltt_serialize_cb *callbacks;
	53	long cb_args[LTT_NR_CALLBACKS];
	54	unsigned int cb_idx;
	55	};
	56
11b5a3c2	57	size_t ltt_serialize_data(struct lib_ring_buffer *buf, size_t buf_offset,
1c8284eb MD	58	struct ltt_serialize_closure *closure,
	59	void *serialize_private, unsigned int stack_pos_ctx,
	60	int largest_align, const char fmt, va_list *args);
	61
1c8284eb MD	62	enum ltt_channels {
	63	LTT_CHANNEL_METADATA,
	64	LTT_CHANNEL_FD_STATE,
	65	LTT_CHANNEL_GLOBAL_STATE,
	66	LTT_CHANNEL_IRQ_STATE,
	67	LTT_CHANNEL_MODULE_STATE,
	68	LTT_CHANNEL_NETIF_STATE,
	69	LTT_CHANNEL_SOFTIRQ_STATE,
	70	LTT_CHANNEL_SWAP_STATE,
	71	LTT_CHANNEL_SYSCALL_STATE,
	72	LTT_CHANNEL_TASK_STATE,
	73	LTT_CHANNEL_VM_STATE,
	74	LTT_CHANNEL_FS,
	75	LTT_CHANNEL_INPUT,
	76	LTT_CHANNEL_IPC,
	77	LTT_CHANNEL_KERNEL,
	78	LTT_CHANNEL_MM,
	79	LTT_CHANNEL_RCU,
	80	LTT_CHANNEL_DEFAULT,
	81	};
	82
11b5a3c2 MD	83	#if 0
11b5a3c2 MD	84	size_t ltt_serialize_printf(struct lib_ring_buffer *buf, unsigned long buf_offset,
1c8284eb MD	85	size_t msg_size, char output, size_t outlen,
	86	const char *fmt);
	87
	88	/*
	89	* Unique ID assigned to each registered probe.
	90	*/
	91	enum marker_id {
	92	MARKER_ID_SET_MARKER_ID = 0, /* Static IDs available (range 0-7) */
	93	MARKER_ID_SET_MARKER_FORMAT,
	94	MARKER_ID_COMPACT, /* Compact IDs (range: 8-127) */
	95	MARKER_ID_DYNAMIC, /* Dynamic IDs (range: 128-65535) */
	96	};
	97
	98	/* static ids 0-1 reserved for internal use. */
	99	#define MARKER_CORE_IDS 2
	100	static __inline__ enum marker_id marker_id_type(uint16_t id)
	101	{
	102	if (id < MARKER_CORE_IDS)
	103	return (enum marker_id)id;
	104	else
	105	return MARKER_ID_DYNAMIC;
	106	}
	107
	108	struct user_dbg_data {
	109	unsigned long avail_size;
	110	unsigned long write;
	111	unsigned long read;
	112	};
	113
1c8284eb MD	114	enum trace_mode { LTT_TRACE_NORMAL, LTT_TRACE_FLIGHT, LTT_TRACE_HYBRID };
	115
	116	#define CHANNEL_FLAG_ENABLE (1U<<0)
	117	#define CHANNEL_FLAG_OVERWRITE (1U<<1)
11b5a3c2	118	#endif //0
1c8284eb	119
c0e31d2e	120	#if 0
1c8284eb MD	121	/* Per-trace information - each trace/flight recorder represented by one */
	122	struct ltt_trace {
	123	/* First 32 bytes cache-hot cacheline */
	124	struct list_head list;
7514523f	125	struct ltt_chan **channels;
1c8284eb MD	126	unsigned int nr_channels;
	127	int active;
	128	/* Second 32 bytes cache-hot cacheline */
	129	struct ltt_trace_ops *ops;
	130	u32 freq_scale;
	131	u64 start_freq;
	132	u64 start_tsc;
	133	unsigned long long start_monotonic;
	134	struct timeval start_time;
	135	struct ltt_channel_setting *settings;
	136	struct {
	137	struct dentry *trace_root;
	138	struct dentry *ascii_root;
	139	} dentry;
	140	struct kref kref; /* Each channel has a kref of the trace struct */
	141	struct ltt_transport *transport;
	142	struct kref ltt_transport_kref;
	143	wait_queue_head_t kref_wq; /* Place for ltt_trace_destroy to sleep */
	144	char trace_name[NAME_MAX];
	145	} ____cacheline_aligned;
c0e31d2e	146	#endif //0
1c8284eb	147
7514523f MD	148	/*
7514523f MD	149	* Hardcoded event headers
1c8284eb MD	150	*
	151	* event header for a trace with active heartbeat : 27 bits timestamps
	152	*
	153	* headers are 32-bits aligned. In order to insure such alignment, a dynamic per
	154	* trace alignment value must be done.
	155	*
	156	* Remember that the C compiler does align each member on the boundary
	157	* equivalent to their own size.
	158	*
	159	* As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
	160	* bytes aligned, so the buffer header and trace header are aligned.
	161	*
	162	* Event headers are aligned depending on the trace alignment option.
	163	*
	164	* Note using C structure bitfields for cross-endianness and portability
	165	* concerns.
	166	*/
	167
	168	#define LTT_RESERVED_EVENTS 3
	169	#define LTT_EVENT_BITS 5
	170	#define LTT_FREE_EVENTS ((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
	171	#define LTT_TSC_BITS 27
	172	#define LTT_TSC_MASK ((1 << LTT_TSC_BITS) - 1)
	173
7514523f	174	struct event_header {
1c8284eb MD	175	u32 id_time; /* 5 bits event id (MSB); 27 bits time (LSB) */
	176	};
	177
	178	/* Reservation flags */
	179	#define LTT_RFLAG_ID (1 << 0)
	180	#define LTT_RFLAG_ID_SIZE (1 << 1)
	181	#define LTT_RFLAG_ID_SIZE_TSC (1 << 2)
	182
	183	#define LTT_MAX_SMALL_SIZE 0xFFFFU
	184
	185	/*
	186	* We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
	187	* specifically with CPU frequency scaling someday, so using an interpolation
	188	* between the start and end of buffer values is not flexible enough. Using an
	189	* immediate frequency value permits to calculate directly the times for parts
	190	* of a buffer that would be before a frequency change.
	191	*
	192	* Keep the natural field alignment for _each field_ within this structure if
	193	* you ever add/remove a field from this header. Packed attribute is not used
	194	* because gcc generates poor code on at least powerpc and mips. Don't ever
	195	* let gcc add padding between the structure elements.
	196	*/
1c25284c MD	197	struct packet_header {
1c25284c MD	198	uint32_t magic; /*
1c8284eb MD	199	* Trace magic number.
	200	* contains endianness information.
	201	*/
1c25284c MD	202	uint8_t trace_uuid[16];
	203	uint32_t stream_id;
	204	uint64_t timestamp_begin; /* Cycle count at subbuffer start */
	205	uint64_t timestamp_end; /* Cycle count at subbuffer end */
	206	uint32_t content_size; /* Size of data in subbuffer */
	207	uint32_t packet_size; /* Subbuffer size (include padding) */
	208	uint32_t events_lost; /*
	209	* Events lost in this subbuffer since
	210	* the beginning of the trace.
	211	* (may overflow)
	212	*/
	213	/* TODO: move to metadata */
	214	#if 0
1c8284eb MD	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) */
1c25284c	226	#endif //0
1c8284eb MD	227	uint8_t header_end[0]; /* End of header */
	228	};
	229
7514523f	230	static inline notrace u64 lib_ring_buffer_clock_read(struct channel *chan)
1c8284eb	231	{
7514523f	232	return trace_clock_read64();
1c8284eb MD	233	}
	234
	235	/*
7514523f MD	236	* record_header_size - Calculate the header size and padding necessary.
	237	* @config: ring buffer instance configuration
	238	* @chan: channel
	239	* @offset: offset in the write buffer
	240	* @data_size: size of the payload
	241	* @pre_header_padding: padding to add before the header (output)
	242	* @rflags: reservation flags
	243	* @ctx: reservation context
1c8284eb	244	*
7514523f	245	* Returns the event header size (including padding).
1c8284eb MD	246	*
	247	* Important note :
	248	* The event header must be 32-bits. The total offset calculated here :
	249	*
	250	* Alignment of header struct on 32 bits (min arch size, header size)
	251	* + sizeof(header struct) (32-bits)
	252	* + (opt) u16 (ext. event id)
	253	* + (opt) u16 (event_size)
	254	* (if event_size == LTT_MAX_SMALL_SIZE, has ext. event size)
	255	* + (opt) u32 (ext. event size)
	256	* + (opt) u64 full TSC (aligned on min(64-bits, arch size))
	257	*
	258	* The payload must itself determine its own alignment from the biggest type it
	259	* contains.
7514523f	260	*/
1c8284eb	261	static __inline__
7514523f MD	262	unsigned char record_header_size(const struct lib_ring_buffer_config *config,
	263	struct channel *chan, size_t offset,
	264	size_t data_size, size_t *pre_header_padding,
	265	unsigned int rflags,
	266	struct lib_ring_buffer_ctx *ctx)
1c8284eb MD	267	{
	268	size_t orig_offset = offset;
	269	size_t padding;
	270
7514523f	271	BUILD_BUG_ON(sizeof(struct event_header) != sizeof(u32));
1c8284eb	272
7514523f MD	273	padding = lib_ring_buffer_align(config, offset,
7514523f MD	274	sizeof(struct event_header));
1c8284eb	275	offset += padding;
7514523f	276	offset += sizeof(struct event_header);
1c8284eb MD	277
	278	if (unlikely(rflags)) {
	279	switch (rflags) {
	280	case LTT_RFLAG_ID_SIZE_TSC:
	281	offset += sizeof(u16) + sizeof(u16);
	282	if (data_size >= LTT_MAX_SMALL_SIZE)
	283	offset += sizeof(u32);
	284	offset += ltt_align(offset, sizeof(u64));
	285	offset += sizeof(u64);
	286	break;
	287	case LTT_RFLAG_ID_SIZE:
	288	offset += sizeof(u16) + sizeof(u16);
	289	if (data_size >= LTT_MAX_SMALL_SIZE)
	290	offset += sizeof(u32);
	291	break;
	292	case LTT_RFLAG_ID:
	293	offset += sizeof(u16);
	294	break;
	295	}
	296	}
	297
7514523f	298	*pre_header_padding = padding;
1c8284eb MD	299	return offset - orig_offset;
	300	}
	301
7514523f MD	302	#include <linux/ringbuffer/api.h>
7514523f MD	303
1c8284eb	304	extern
1c25284c MD	305	void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
	306	struct lib_ring_buffer_ctx *ctx,
	307	u16 eID, u32 event_size);
1c8284eb MD	308
	309	/*
	310	* ltt_write_event_header
	311	*
	312	* Writes the event header to the offset (already aligned on 32-bits).
	313	*
7514523f MD	314	* @config: ring buffer instance configuration
7514523f MD	315	* @ctx: reservation context
1c8284eb MD	316	* @eID : event ID
1c8284eb MD	317	* @event_size : size of the event, excluding the event header.
1c8284eb MD	318	*/
1c8284eb MD	319	static __inline__
7514523f MD	320	void ltt_write_event_header(const struct lib_ring_buffer_config *config,
	321	struct lib_ring_buffer_ctx *ctx,
	322	u16 eID, u32 event_size)
1c8284eb	323	{
7514523f	324	struct event_header header;
1c8284eb	325
7514523f	326	if (unlikely(ctx->rflags))
1c8284eb MD	327	goto slow_path;
	328
	329	header.id_time = eID << LTT_TSC_BITS;
7514523f MD	330	header.id_time \|= (u32)ctx->tsc & LTT_TSC_MASK;
7514523f MD	331	lib_ring_buffer_write(config, ctx, &header, sizeof(header));
1c8284eb MD	332
1c8284eb MD	333	slow_path:
7514523f	334	ltt_write_event_header_slow(config, ctx, eID, event_size);
1c8284eb MD	335	}
1c8284eb MD	336
7514523f	337	#if 0
1c8284eb MD	338	/*
	339	* ltt_read_event_header
	340	* buf_offset must aligned on 32 bits
	341	*/
	342	static __inline__
	343	size_t ltt_read_event_header(struct ltt_chanbuf_alloc *bufa, long buf_offset,
	344	u64 tsc, u32 event_size, u16 *eID,
	345	unsigned int *rflags)
	346	{
	347	struct ltt_event_header header;
	348	u16 small_size;
	349
	350	ltt_relay_read(bufa, buf_offset, &header, sizeof(header));
	351	buf_offset += sizeof(header);
	352
	353	*event_size = INT_MAX;
	354	*eID = header.id_time >> LTT_TSC_BITS;
	355	*tsc = header.id_time & LTT_TSC_MASK;
	356
	357	switch (*eID) {
	358	case 29:
	359	*rflags = LTT_RFLAG_ID_SIZE_TSC;
	360	ltt_relay_read(bufa, buf_offset, eID, sizeof(u16));
	361	buf_offset += sizeof(u16);
	362	ltt_relay_read(bufa, buf_offset, &small_size, sizeof(u16));
	363	buf_offset += sizeof(u16);
	364	if (small_size == LTT_MAX_SMALL_SIZE) {
	365	ltt_relay_read(bufa, buf_offset, event_size,
	366	sizeof(u32));
	367	buf_offset += sizeof(u32);
	368	} else
	369	*event_size = small_size;
	370	buf_offset += ltt_align(buf_offset, sizeof(u64));
	371	ltt_relay_read(bufa, buf_offset, tsc, sizeof(u64));
	372	buf_offset += sizeof(u64);
	373	break;
	374	case 30:
	375	*rflags = LTT_RFLAG_ID_SIZE;
	376	ltt_relay_read(bufa, buf_offset, eID, sizeof(u16));
	377	buf_offset += sizeof(u16);
	378	ltt_relay_read(bufa, buf_offset, &small_size, sizeof(u16));
	379	buf_offset += sizeof(u16);
	380	if (small_size == LTT_MAX_SMALL_SIZE) {
	381	ltt_relay_read(bufa, buf_offset, event_size,
	382	sizeof(u32));
	383	buf_offset += sizeof(u32);
	384	} else
	385	*event_size = small_size;
	386	break;
	387	case 31:
	388	*rflags = LTT_RFLAG_ID;
	389	ltt_relay_read(bufa, buf_offset, eID, sizeof(u16));
	390	buf_offset += sizeof(u16);
	391	break;
	392	default:
	393	*rflags = 0;
	394	break;
	395	}
	396
	397	return buf_offset;
	398	}
7514523f	399	#endif //0
1c8284eb	400
1c8284eb	401	/* Tracer properties */
1c25284c MD	402	#define CTF_MAGIC_NUMBER 0xC1FC1FC1
	403	#define LTT_TRACER_VERSION_MAJOR 3
	404	#define LTT_TRACER_VERSION_MINOR 0
1c8284eb MD	405
	406	/**
	407	* ltt_write_trace_header - Write trace header
7514523f	408	* @priv: Private data (struct trace)
1c8284eb MD	409	* @header: Memory address where the information must be written to
	410	*/
	411	static __inline__
1c25284c MD	412	void write_trace_header(const struct lib_ring_buffer_config *config,
1c25284c MD	413	struct packet_header *header)
1c8284eb	414	{
1c25284c MD	415	header->magic = CTF_MAGIC_NUMBER;
	416	#if 0
	417	/* TODO: move start time to metadata */
1c8284eb MD	418	header->major_version = LTT_TRACER_VERSION_MAJOR;
	419	header->minor_version = LTT_TRACER_VERSION_MINOR;
	420	header->arch_size = sizeof(void *);
1c25284c MD	421	header->alignment = lib_ring_buffer_get_alignment(config);
	422	header->start_time_sec = ltt_chan->session->start_time.tv_sec;
	423	header->start_time_usec = ltt_chan->session->start_time.tv_usec;
	424	header->start_freq = ltt_chan->session->start_freq;
	425	header->freq_scale = ltt_chan->session->freq_scale;
	426	#endif //0
1c8284eb MD	427	}
	428
	429	/*
	430	* Size reserved for high priority events (interrupts, NMI, BH) at the end of a
	431	* nearly full buffer. User space won't use this last amount of space when in
	432	* blocking mode. This space also includes the event header that would be
	433	* written by this user space event.
	434	*/
	435	#define LTT_RESERVE_CRITICAL 4096
	436
	437	/* Register and unregister function pointers */
	438
	439	enum ltt_module_function {
	440	LTT_FUNCTION_RUN_FILTER,
	441	LTT_FUNCTION_FILTER_CONTROL,
	442	LTT_FUNCTION_STATEDUMP
	443	};
	444
	445	extern int ltt_module_register(enum ltt_module_function name, void *function,
	446	struct module *owner);
	447	extern void ltt_module_unregister(enum ltt_module_function name);
	448
1c8284eb MD	449	/* Exported control function */
1c8284eb MD	450
1c8284eb MD	451	void ltt_core_register(int (function)(u8, void ));
	452
	453	void ltt_core_unregister(void);
	454
1c8284eb MD	455	extern
	456	void ltt_statedump_register_kprobes_dump(void (callback)(void call_data));
	457	extern
	458	void ltt_statedump_unregister_kprobes_dump(void (callback)(void call_data));
	459
	460	extern void ltt_dump_softirq_vec(void *call_data);
	461
f277b4c1	462	#ifdef CONFIG_HAVE_LTT_DUMP_TABLES
1c8284eb MD	463	extern void ltt_dump_sys_call_table(void *call_data);
1c8284eb MD	464	extern void ltt_dump_idt_table(void *call_data);
f277b4c1 MD	465	#else
	466	static inline void ltt_dump_sys_call_table(void *call_data)
	467	{
	468	}
	469
	470	static inline void ltt_dump_idt_table(void *call_data)
	471	{
	472	}
	473	#endif
1c8284eb	474
1c8284eb	475	#endif /* _LTT_TRACER_H */