[lttng-modules.git] / ltt-ring-buffer-metadata-client.h

/*
 * ltt-ring-buffer-client.h
 *
 * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * LTTng lib ring buffer client template.
 *
 * Dual LGPL v2.1/GPL v2 license.
 */

#include <linux/module.h>
#include <linux/types.h>
#include "wrapper/vmalloc.h"	/* for wrapper_vmalloc_sync_all() */
#include "ltt-events.h"
#include "ltt-tracer.h"

struct metadata_packet_header {
	uint32_t magic;			/* 0x75D11D57 */
	uint8_t  uuid[16];		/* Unique Universal Identifier */
	uint32_t checksum;		/* 0 if unused */
	uint32_t content_size;		/* in bits */
	uint32_t packet_size;		/* in bits */
	uint8_t  compression_scheme;	/* 0 if unused */
	uint8_t  encryption_scheme;	/* 0 if unused */
	uint8_t  checksum_scheme;	/* 0 if unused */
	uint8_t  major;			/* CTF spec major version number */
	uint8_t  minor;			/* CTF spec minor version number */
	uint8_t  header_end[0];
};

struct metadata_record_header {
	uint8_t header_end[0];		/* End of header */
};

static const struct lib_ring_buffer_config client_config;

static inline
u64 lib_ring_buffer_clock_read(struct channel *chan)
{
	return 0;
}

static inline
unsigned char record_header_size(const struct lib_ring_buffer_config *config,
				 struct channel *chan, size_t offset,
				 size_t *pre_header_padding,
				 struct lib_ring_buffer_ctx *ctx)
{
	return 0;
}

#include "wrapper/ringbuffer/api.h"

static u64 client_ring_buffer_clock_read(struct channel *chan)
{
	return 0;
}

static
size_t client_record_header_size(const struct lib_ring_buffer_config *config,
				 struct channel *chan, size_t offset,
				 size_t *pre_header_padding,
				 struct lib_ring_buffer_ctx *ctx)
{
	return 0;
}

/**
 * client_packet_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 size_t client_packet_header_size(void)
{
	return offsetof(struct metadata_packet_header, header_end);
}

static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
				unsigned int subbuf_idx)
{
	struct channel *chan = buf->backend.chan;
	struct metadata_packet_header *header =
		(struct metadata_packet_header *)
			lib_ring_buffer_offset_address(&buf->backend,
				subbuf_idx * chan->backend.subbuf_size);
	struct ltt_channel *ltt_chan = channel_get_private(chan);
	struct ltt_session *session = ltt_chan->session;

	header->magic = TSDL_MAGIC_NUMBER;
	memcpy(header->uuid, session->uuid.b, sizeof(session->uuid));
	header->checksum = 0;		/* 0 if unused */
	header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
	header->packet_size = 0xFFFFFFFF;  /* in bits, for debugging */
	header->compression_scheme = 0;	/* 0 if unused */
	header->encryption_scheme = 0;	/* 0 if unused */
	header->checksum_scheme = 0;	/* 0 if unused */
	header->major = CTF_SPEC_MAJOR;
	header->minor = CTF_SPEC_MINOR;
}

/*
 * offset is assumed to never be 0 here : never deliver a completely empty
 * subbuffer. data_size is between 1 and subbuf_size.
 */
static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
			      unsigned int subbuf_idx, unsigned long data_size)
{
	struct channel *chan = buf->backend.chan;
	struct metadata_packet_header *header =
		(struct metadata_packet_header *)
			lib_ring_buffer_offset_address(&buf->backend,
				subbuf_idx * chan->backend.subbuf_size);
	unsigned long records_lost = 0;

	header->content_size = data_size * CHAR_BIT;		/* in bits */
	header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
	/*
	 * We do not care about the records lost count, because the metadata
	 * channel waits and retry.
	 */
	(void) lib_ring_buffer_get_records_lost_full(&client_config, buf);
	records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
	records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
	WARN_ON_ONCE(records_lost != 0);
}

static int client_buffer_create(struct lib_ring_buffer *buf, void *priv,
				int cpu, const char *name)
{
	return 0;
}

static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu)
{
}

static const struct lib_ring_buffer_config client_config = {
	.cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
	.cb.record_header_size = client_record_header_size,
	.cb.subbuffer_header_size = client_packet_header_size,
	.cb.buffer_begin = client_buffer_begin,
	.cb.buffer_end = client_buffer_end,
	.cb.buffer_create = client_buffer_create,
	.cb.buffer_finalize = client_buffer_finalize,

	.tsc_bits = 0,
	.alloc = RING_BUFFER_ALLOC_GLOBAL,
	.sync = RING_BUFFER_SYNC_GLOBAL,
	.mode = RING_BUFFER_MODE_TEMPLATE,
	.backend = RING_BUFFER_PAGE,
	.output = RING_BUFFER_OUTPUT_TEMPLATE,
	.oops = RING_BUFFER_OOPS_CONSISTENCY,
	.ipi = RING_BUFFER_IPI_BARRIER,
	.wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
};

static
struct channel *_channel_create(const char *name,
				struct ltt_channel *ltt_chan, void *buf_addr,
				size_t subbuf_size, size_t num_subbuf,
				unsigned int switch_timer_interval,
				unsigned int read_timer_interval)
{
	return channel_create(&client_config, name, ltt_chan, buf_addr,
			      subbuf_size, num_subbuf, switch_timer_interval,
			      read_timer_interval);
}

static
void ltt_channel_destroy(struct channel *chan)
{
	channel_destroy(chan);
}

static
struct lib_ring_buffer *ltt_buffer_read_open(struct channel *chan)
{
	struct lib_ring_buffer *buf;

	buf = channel_get_ring_buffer(&client_config, chan, 0);
	if (!lib_ring_buffer_open_read(buf))
		return buf;
	return NULL;
}

static
int ltt_buffer_has_read_closed_stream(struct channel *chan)
{
	struct lib_ring_buffer *buf;
	int cpu;

	for_each_channel_cpu(cpu, chan) {
		buf = channel_get_ring_buffer(&client_config, chan, cpu);
		if (!atomic_long_read(&buf->active_readers))
			return 1;
	}
	return 0;
}

static
void ltt_buffer_read_close(struct lib_ring_buffer *buf)
{
	lib_ring_buffer_release_read(buf);
}

static
int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx, uint32_t event_id)
{
	return lib_ring_buffer_reserve(&client_config, ctx);
}

static
void ltt_event_commit(struct lib_ring_buffer_ctx *ctx)
{
	lib_ring_buffer_commit(&client_config, ctx);
}

static
void ltt_event_write(struct lib_ring_buffer_ctx *ctx, const void *src,
		     size_t len)
{
	lib_ring_buffer_write(&client_config, ctx, src, len);
}

static
size_t ltt_packet_avail_size(struct channel *chan)
			     
{
	unsigned long o_begin;
	struct lib_ring_buffer *buf;

	buf = chan->backend.buf;	/* Only for global buffer ! */
	o_begin = v_read(&client_config, &buf->offset);
	if (subbuf_offset(o_begin, chan) != 0) {
		return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
	} else {
		return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
			- sizeof(struct metadata_packet_header);
	}
}

static
wait_queue_head_t *ltt_get_writer_buf_wait_queue(struct channel *chan, int cpu)
{
	struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config,
					chan, cpu);
	return &buf->write_wait;
}

static
wait_queue_head_t *ltt_get_hp_wait_queue(struct channel *chan)
{
	return &chan->hp_wait;
}

static
int ltt_is_finalized(struct channel *chan)
{
	return lib_ring_buffer_channel_is_finalized(chan);
}

static
int ltt_is_disabled(struct channel *chan)
{
	return lib_ring_buffer_channel_is_disabled(chan);
}

static struct ltt_transport ltt_relay_transport = {
	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
	.owner = THIS_MODULE,
	.ops = {
		.channel_create = _channel_create,
		.channel_destroy = ltt_channel_destroy,
		.buffer_read_open = ltt_buffer_read_open,
		.buffer_has_read_closed_stream =
			ltt_buffer_has_read_closed_stream,
		.buffer_read_close = ltt_buffer_read_close,
		.event_reserve = ltt_event_reserve,
		.event_commit = ltt_event_commit,
		.event_write = ltt_event_write,
		.packet_avail_size = ltt_packet_avail_size,
		.get_writer_buf_wait_queue = ltt_get_writer_buf_wait_queue,
		.get_hp_wait_queue = ltt_get_hp_wait_queue,
		.is_finalized = ltt_is_finalized,
		.is_disabled = ltt_is_disabled,
	},
};

static int __init ltt_ring_buffer_client_init(void)
{
	/*
	 * This vmalloc sync all also takes care of the lib ring buffer
	 * vmalloc'd module pages when it is built as a module into LTTng.
	 */
	wrapper_vmalloc_sync_all();
	ltt_transport_register(&ltt_relay_transport);
	return 0;
}

module_init(ltt_ring_buffer_client_init);

static void __exit ltt_ring_buffer_client_exit(void)
{
	ltt_transport_unregister(&ltt_relay_transport);
}

module_exit(ltt_ring_buffer_client_exit);

MODULE_LICENSE("GPL and additional rights");
MODULE_AUTHOR("Mathieu Desnoyers");
MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
		   " client");
Commit	Line	Data
881833e3 MD	1	/*
	2	* ltt-ring-buffer-client.h
	3	*
	4	* Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	5	*
	6	* LTTng lib ring buffer client template.
	7	*
	8	* Dual LGPL v2.1/GPL v2 license.
	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/types.h>
	13	#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
	14	#include "ltt-events.h"
	15	#include "ltt-tracer.h"
	16
881833e3 MD	17	struct metadata_packet_header {
881833e3 MD	18	uint32_t magic; /* 0x75D11D57 */
1ec3f75a	19	uint8_t uuid[16]; /* Unique Universal Identifier */
881833e3 MD	20	uint32_t checksum; /* 0 if unused */
	21	uint32_t content_size; /* in bits */
	22	uint32_t packet_size; /* in bits */
	23	uint8_t compression_scheme; /* 0 if unused */
	24	uint8_t encryption_scheme; /* 0 if unused */
	25	uint8_t checksum_scheme; /* 0 if unused */
4173df96 MD	26	uint8_t major; /* CTF spec major version number */
4173df96 MD	27	uint8_t minor; /* CTF spec minor version number */
881833e3 MD	28	uint8_t header_end[0];
	29	};
	30
	31	struct metadata_record_header {
	32	uint8_t header_end[0]; /* End of header */
	33	};
	34
	35	static const struct lib_ring_buffer_config client_config;
	36
	37	static inline
	38	u64 lib_ring_buffer_clock_read(struct channel *chan)
	39	{
	40	return 0;
	41	}
	42
	43	static inline
	44	unsigned char record_header_size(const struct lib_ring_buffer_config *config,
	45	struct channel *chan, size_t offset,
64c796d8	46	size_t *pre_header_padding,
881833e3 MD	47	struct lib_ring_buffer_ctx *ctx)
	48	{
	49	return 0;
	50	}
	51
	52	#include "wrapper/ringbuffer/api.h"
	53
	54	static u64 client_ring_buffer_clock_read(struct channel *chan)
	55	{
	56	return 0;
	57	}
	58
	59	static
	60	size_t client_record_header_size(const struct lib_ring_buffer_config *config,
	61	struct channel *chan, size_t offset,
881833e3	62	size_t *pre_header_padding,
881833e3 MD	63	struct lib_ring_buffer_ctx *ctx)
	64	{
	65	return 0;
	66	}
	67
	68	/**
	69	* client_packet_header_size - called on buffer-switch to a new sub-buffer
	70	*
	71	* Return header size without padding after the structure. Don't use packed
	72	* structure because gcc generates inefficient code on some architectures
	73	* (powerpc, mips..)
	74	*/
	75	static size_t client_packet_header_size(void)
	76	{
	77	return offsetof(struct metadata_packet_header, header_end);
	78	}
	79
	80	static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
	81	unsigned int subbuf_idx)
	82	{
	83	struct channel *chan = buf->backend.chan;
	84	struct metadata_packet_header *header =
	85	(struct metadata_packet_header *)
	86	lib_ring_buffer_offset_address(&buf->backend,
	87	subbuf_idx * chan->backend.subbuf_size);
9115fbdc MD	88	struct ltt_channel *ltt_chan = channel_get_private(chan);
9115fbdc MD	89	struct ltt_session *session = ltt_chan->session;
881833e3 MD	90
881833e3 MD	91	header->magic = TSDL_MAGIC_NUMBER;
1ec3f75a	92	memcpy(header->uuid, session->uuid.b, sizeof(session->uuid));
881833e3 MD	93	header->checksum = 0; /* 0 if unused */
	94	header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
	95	header->packet_size = 0xFFFFFFFF; /* in bits, for debugging */
	96	header->compression_scheme = 0; /* 0 if unused */
	97	header->encryption_scheme = 0; /* 0 if unused */
	98	header->checksum_scheme = 0; /* 0 if unused */
4173df96 MD	99	header->major = CTF_SPEC_MAJOR;
4173df96 MD	100	header->minor = CTF_SPEC_MINOR;
881833e3 MD	101	}
	102
	103	/*
	104	* offset is assumed to never be 0 here : never deliver a completely empty
	105	* subbuffer. data_size is between 1 and subbuf_size.
	106	*/
	107	static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
	108	unsigned int subbuf_idx, unsigned long data_size)
	109	{
	110	struct channel *chan = buf->backend.chan;
d793d5e1	111	struct metadata_packet_header *header =
1ec3f75a	112	(struct metadata_packet_header *)
881833e3 MD	113	lib_ring_buffer_offset_address(&buf->backend,
	114	subbuf_idx * chan->backend.subbuf_size);
	115	unsigned long records_lost = 0;
	116
	117	header->content_size = data_size * CHAR_BIT; /* in bits */
	118	header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
71c1d843 MD	119	/*
	120	* We do not care about the records lost count, because the metadata
	121	* channel waits and retry.
	122	*/
	123	(void) lib_ring_buffer_get_records_lost_full(&client_config, buf);
881833e3 MD	124	records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
	125	records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
	126	WARN_ON_ONCE(records_lost != 0);
	127	}
	128
	129	static int client_buffer_create(struct lib_ring_buffer buf, void priv,
	130	int cpu, const char *name)
	131	{
	132	return 0;
	133	}
	134
	135	static void client_buffer_finalize(struct lib_ring_buffer buf, void priv, int cpu)
	136	{
	137	}
	138
	139	static const struct lib_ring_buffer_config client_config = {
	140	.cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
	141	.cb.record_header_size = client_record_header_size,
	142	.cb.subbuffer_header_size = client_packet_header_size,
	143	.cb.buffer_begin = client_buffer_begin,
	144	.cb.buffer_end = client_buffer_end,
	145	.cb.buffer_create = client_buffer_create,
	146	.cb.buffer_finalize = client_buffer_finalize,
	147
	148	.tsc_bits = 0,
	149	.alloc = RING_BUFFER_ALLOC_GLOBAL,
	150	.sync = RING_BUFFER_SYNC_GLOBAL,
	151	.mode = RING_BUFFER_MODE_TEMPLATE,
	152	.backend = RING_BUFFER_PAGE,
2db1399a	153	.output = RING_BUFFER_OUTPUT_TEMPLATE,
881833e3 MD	154	.oops = RING_BUFFER_OOPS_CONSISTENCY,
	155	.ipi = RING_BUFFER_IPI_BARRIER,
	156	.wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
	157	};
	158
	159	static
	160	struct channel _channel_create(const char name,
89fff18e	161	struct ltt_channel ltt_chan, void buf_addr,
881833e3 MD	162	size_t subbuf_size, size_t num_subbuf,
	163	unsigned int switch_timer_interval,
	164	unsigned int read_timer_interval)
	165	{
89fff18e	166	return channel_create(&client_config, name, ltt_chan, buf_addr,
881833e3 MD	167	subbuf_size, num_subbuf, switch_timer_interval,
	168	read_timer_interval);
	169	}
	170
	171	static
	172	void ltt_channel_destroy(struct channel *chan)
	173	{
	174	channel_destroy(chan);
	175	}
	176
	177	static
	178	struct lib_ring_buffer ltt_buffer_read_open(struct channel chan)
	179	{
	180	struct lib_ring_buffer *buf;
881833e3	181
cd4bd11f MD	182	buf = channel_get_ring_buffer(&client_config, chan, 0);
	183	if (!lib_ring_buffer_open_read(buf))
	184	return buf;
881833e3 MD	185	return NULL;
	186	}
	187
f71ecafa MD	188	static
	189	int ltt_buffer_has_read_closed_stream(struct channel *chan)
	190	{
	191	struct lib_ring_buffer *buf;
	192	int cpu;
	193
	194	for_each_channel_cpu(cpu, chan) {
	195	buf = channel_get_ring_buffer(&client_config, chan, cpu);
	196	if (!atomic_long_read(&buf->active_readers))
	197	return 1;
	198	}
	199	return 0;
	200	}
	201
881833e3 MD	202	static
	203	void ltt_buffer_read_close(struct lib_ring_buffer *buf)
	204	{
	205	lib_ring_buffer_release_read(buf);
881833e3 MD	206	}
881833e3 MD	207
c099397a	208	static
64c796d8	209	int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx, uint32_t event_id)
881833e3 MD	210	{
	211	return lib_ring_buffer_reserve(&client_config, ctx);
	212	}
	213
c099397a	214	static
881833e3 MD	215	void ltt_event_commit(struct lib_ring_buffer_ctx *ctx)
	216	{
	217	lib_ring_buffer_commit(&client_config, ctx);
	218	}
	219
c099397a	220	static
881833e3 MD	221	void ltt_event_write(struct lib_ring_buffer_ctx ctx, const void src,
	222	size_t len)
	223	{
	224	lib_ring_buffer_write(&client_config, ctx, src, len);
	225	}
	226
1ec3f75a MD	227	static
	228	size_t ltt_packet_avail_size(struct channel *chan)
	229
	230	{
	231	unsigned long o_begin;
	232	struct lib_ring_buffer *buf;
	233
	234	buf = chan->backend.buf; /* Only for global buffer ! */
	235	o_begin = v_read(&client_config, &buf->offset);
	236	if (subbuf_offset(o_begin, chan) != 0) {
	237	return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
	238	} else {
	239	return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
	240	- sizeof(struct metadata_packet_header);
	241	}
	242	}
	243
c099397a	244	static
71c1d843	245	wait_queue_head_t ltt_get_writer_buf_wait_queue(struct channel chan, int cpu)
c099397a	246	{
71c1d843 MD	247	struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config,
	248	chan, cpu);
	249	return &buf->write_wait;
24cedcfe MD	250	}
	251
	252	static
	253	wait_queue_head_t ltt_get_hp_wait_queue(struct channel chan)
	254	{
	255	return &chan->hp_wait;
	256	}
	257
	258	static
	259	int ltt_is_finalized(struct channel *chan)
	260	{
	261	return lib_ring_buffer_channel_is_finalized(chan);
c099397a MD	262	}
c099397a MD	263
254ec7bc MD	264	static
	265	int ltt_is_disabled(struct channel *chan)
	266	{
	267	return lib_ring_buffer_channel_is_disabled(chan);
	268	}
	269
881833e3 MD	270	static struct ltt_transport ltt_relay_transport = {
	271	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
	272	.owner = THIS_MODULE,
	273	.ops = {
	274	.channel_create = _channel_create,
	275	.channel_destroy = ltt_channel_destroy,
	276	.buffer_read_open = ltt_buffer_read_open,
f71ecafa MD	277	.buffer_has_read_closed_stream =
f71ecafa MD	278	ltt_buffer_has_read_closed_stream,
881833e3 MD	279	.buffer_read_close = ltt_buffer_read_close,
	280	.event_reserve = ltt_event_reserve,
	281	.event_commit = ltt_event_commit,
	282	.event_write = ltt_event_write,
1ec3f75a	283	.packet_avail_size = ltt_packet_avail_size,
71c1d843	284	.get_writer_buf_wait_queue = ltt_get_writer_buf_wait_queue,
24cedcfe MD	285	.get_hp_wait_queue = ltt_get_hp_wait_queue,
24cedcfe MD	286	.is_finalized = ltt_is_finalized,
254ec7bc	287	.is_disabled = ltt_is_disabled,
881833e3 MD	288	},
	289	};
	290
	291	static int __init ltt_ring_buffer_client_init(void)
	292	{
	293	/*
	294	* This vmalloc sync all also takes care of the lib ring buffer
	295	* vmalloc'd module pages when it is built as a module into LTTng.
	296	*/
	297	wrapper_vmalloc_sync_all();
881833e3 MD	298	ltt_transport_register(&ltt_relay_transport);
	299	return 0;
	300	}
	301
	302	module_init(ltt_ring_buffer_client_init);
	303
	304	static void __exit ltt_ring_buffer_client_exit(void)
	305	{
881833e3 MD	306	ltt_transport_unregister(&ltt_relay_transport);
	307	}
	308
	309	module_exit(ltt_ring_buffer_client_exit);
	310
	311	MODULE_LICENSE("GPL and additional rights");
	312	MODULE_AUTHOR("Mathieu Desnoyers");
	313	MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
	314	" client");