[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 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_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
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 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,
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,
	60	size_t data_size,
	61	size_t *pre_header_padding,
	62	unsigned int rflags,
	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 */
	99	}
	100
	101	/*
	102	* offset is assumed to never be 0 here : never deliver a completely empty
	103	* subbuffer. data_size is between 1 and subbuf_size.
	104	*/
	105	static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
	106	unsigned int subbuf_idx, unsigned long data_size)
	107	{
	108	struct channel *chan = buf->backend.chan;
d793d5e1	109	struct metadata_packet_header *header =
1ec3f75a	110	(struct metadata_packet_header *)
881833e3 MD	111	lib_ring_buffer_offset_address(&buf->backend,
	112	subbuf_idx * chan->backend.subbuf_size);
	113	unsigned long records_lost = 0;
	114
	115	header->content_size = data_size * CHAR_BIT; /* in bits */
	116	header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
	117	records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
	118	records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
	119	records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
	120	WARN_ON_ONCE(records_lost != 0);
	121	}
	122
	123	static int client_buffer_create(struct lib_ring_buffer buf, void priv,
	124	int cpu, const char *name)
	125	{
	126	return 0;
	127	}
	128
	129	static void client_buffer_finalize(struct lib_ring_buffer buf, void priv, int cpu)
	130	{
	131	}
	132
	133	static const struct lib_ring_buffer_config client_config = {
	134	.cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
	135	.cb.record_header_size = client_record_header_size,
	136	.cb.subbuffer_header_size = client_packet_header_size,
	137	.cb.buffer_begin = client_buffer_begin,
	138	.cb.buffer_end = client_buffer_end,
	139	.cb.buffer_create = client_buffer_create,
	140	.cb.buffer_finalize = client_buffer_finalize,
	141
	142	.tsc_bits = 0,
	143	.alloc = RING_BUFFER_ALLOC_GLOBAL,
	144	.sync = RING_BUFFER_SYNC_GLOBAL,
	145	.mode = RING_BUFFER_MODE_TEMPLATE,
	146	.backend = RING_BUFFER_PAGE,
	147	.output = RING_BUFFER_SPLICE,
	148	.oops = RING_BUFFER_OOPS_CONSISTENCY,
	149	.ipi = RING_BUFFER_IPI_BARRIER,
	150	.wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
	151	};
	152
	153	static
	154	struct channel _channel_create(const char name,
89fff18e	155	struct ltt_channel ltt_chan, void buf_addr,
881833e3 MD	156	size_t subbuf_size, size_t num_subbuf,
	157	unsigned int switch_timer_interval,
	158	unsigned int read_timer_interval)
	159	{
89fff18e	160	return channel_create(&client_config, name, ltt_chan, buf_addr,
881833e3 MD	161	subbuf_size, num_subbuf, switch_timer_interval,
	162	read_timer_interval);
	163	}
	164
	165	static
	166	void ltt_channel_destroy(struct channel *chan)
	167	{
	168	channel_destroy(chan);
	169	}
	170
	171	static
	172	struct lib_ring_buffer ltt_buffer_read_open(struct channel chan)
	173	{
	174	struct lib_ring_buffer *buf;
881833e3	175
cd4bd11f MD	176	buf = channel_get_ring_buffer(&client_config, chan, 0);
	177	if (!lib_ring_buffer_open_read(buf))
	178	return buf;
881833e3 MD	179	return NULL;
	180	}
	181
	182	static
	183	void ltt_buffer_read_close(struct lib_ring_buffer *buf)
	184	{
	185	lib_ring_buffer_release_read(buf);
881833e3 MD	186	}
881833e3 MD	187
c099397a	188	static
64c796d8	189	int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx, uint32_t event_id)
881833e3 MD	190	{
	191	return lib_ring_buffer_reserve(&client_config, ctx);
	192	}
	193
c099397a	194	static
881833e3 MD	195	void ltt_event_commit(struct lib_ring_buffer_ctx *ctx)
	196	{
	197	lib_ring_buffer_commit(&client_config, ctx);
	198	}
	199
c099397a	200	static
881833e3 MD	201	void ltt_event_write(struct lib_ring_buffer_ctx ctx, const void src,
	202	size_t len)
	203	{
	204	lib_ring_buffer_write(&client_config, ctx, src, len);
	205	}
	206
1ec3f75a MD	207	static
	208	size_t ltt_packet_avail_size(struct channel *chan)
	209
	210	{
	211	unsigned long o_begin;
	212	struct lib_ring_buffer *buf;
	213
	214	buf = chan->backend.buf; /* Only for global buffer ! */
	215	o_begin = v_read(&client_config, &buf->offset);
	216	if (subbuf_offset(o_begin, chan) != 0) {
	217	return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
	218	} else {
	219	return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
	220	- sizeof(struct metadata_packet_header);
	221	}
	222	}
	223
c099397a MD	224	static
	225	wait_queue_head_t ltt_get_reader_wait_queue(struct ltt_channel chan)
	226	{
	227	return &chan->chan->read_wait;
	228	}
	229
881833e3 MD	230	static struct ltt_transport ltt_relay_transport = {
	231	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
	232	.owner = THIS_MODULE,
	233	.ops = {
	234	.channel_create = _channel_create,
	235	.channel_destroy = ltt_channel_destroy,
	236	.buffer_read_open = ltt_buffer_read_open,
	237	.buffer_read_close = ltt_buffer_read_close,
	238	.event_reserve = ltt_event_reserve,
	239	.event_commit = ltt_event_commit,
	240	.event_write = ltt_event_write,
1ec3f75a	241	.packet_avail_size = ltt_packet_avail_size,
c099397a	242	.get_reader_wait_queue = ltt_get_reader_wait_queue,
881833e3 MD	243	},
	244	};
	245
	246	static int __init ltt_ring_buffer_client_init(void)
	247	{
	248	/*
	249	* This vmalloc sync all also takes care of the lib ring buffer
	250	* vmalloc'd module pages when it is built as a module into LTTng.
	251	*/
	252	wrapper_vmalloc_sync_all();
	253	printk(KERN_INFO "LTT : ltt ring buffer metadata client init\n");
	254	ltt_transport_register(&ltt_relay_transport);
	255	return 0;
	256	}
	257
	258	module_init(ltt_ring_buffer_client_init);
	259
	260	static void __exit ltt_ring_buffer_client_exit(void)
	261	{
	262	printk(KERN_INFO "LTT : ltt ring buffer metadata client exit\n");
	263	ltt_transport_unregister(&ltt_relay_transport);
	264	}
	265
	266	module_exit(ltt_ring_buffer_client_exit);
	267
	268	MODULE_LICENSE("GPL and additional rights");
	269	MODULE_AUTHOR("Mathieu Desnoyers");
	270	MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
	271	" client");