[deliverable/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 data_size, size_t *pre_header_padding,
				 unsigned int rflags,
				 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 data_size,
				 size_t *pre_header_padding,
				 unsigned int rflags,
				 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_SPLICE,
	.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_session *session, 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, session, 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
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)
{
	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 ltt_channel *chan)
{
	return &chan->chan->read_wait;
}

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_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,
	},
};

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();
	printk(KERN_INFO "LTT : ltt ring buffer metadata client init\n");
	ltt_transport_register(&ltt_relay_transport);
	return 0;
}

module_init(ltt_ring_buffer_client_init);

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