[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  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 */
}

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