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

/*
 * lttng-ring-buffer-client.h
 *
 * LTTng lib ring buffer client template.
 *
 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; only
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

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

static struct lttng_transport lttng_relay_transport;

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 lttng_metadata_cache *metadata_cache =
		channel_get_private(chan);

	header->magic = TSDL_MAGIC_NUMBER;
	memcpy(header->uuid, metadata_cache->uuid.b,
		sizeof(metadata_cache->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 int client_timestamp_begin(const struct lib_ring_buffer_config *config,
		struct lib_ring_buffer *buf, uint64_t *timestamp_begin)
{
	return -ENOSYS;
}

static int client_timestamp_end(const struct lib_ring_buffer_config *config,
			struct lib_ring_buffer *bufb,
			uint64_t *timestamp_end)
{
	return -ENOSYS;
}

static int client_events_discarded(const struct lib_ring_buffer_config *config,
			struct lib_ring_buffer *bufb,
			uint64_t *events_discarded)
{
	return -ENOSYS;
}

static int client_current_timestamp(const struct lib_ring_buffer_config *config,
		struct lib_ring_buffer *bufb,
		uint64_t *ts)
{
	return -ENOSYS;
}

static int client_content_size(const struct lib_ring_buffer_config *config,
			struct lib_ring_buffer *bufb,
			uint64_t *content_size)
{
	return -ENOSYS;
}

static int client_packet_size(const struct lib_ring_buffer_config *config,
			struct lib_ring_buffer *bufb,
			uint64_t *packet_size)
{
	return -ENOSYS;
}

static int client_stream_id(const struct lib_ring_buffer_config *config,
			struct lib_ring_buffer *bufb,
			uint64_t *stream_id)
{
	return -ENOSYS;
}

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
void release_priv_ops(void *priv_ops)
{
	module_put(THIS_MODULE);
}

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

static
struct channel *_channel_create(const char *name,
				struct lttng_channel *lttng_chan, void *buf_addr,
				size_t subbuf_size, size_t num_subbuf,
				unsigned int switch_timer_interval,
				unsigned int read_timer_interval)
{
	struct channel *chan;

	chan = channel_create(&client_config, name,
			      lttng_chan->session->metadata_cache, buf_addr,
			      subbuf_size, num_subbuf, switch_timer_interval,
			      read_timer_interval);
	if (chan) {
		/*
		 * Ensure this module is not unloaded before we finish
		 * using lttng_relay_transport.ops.
		 */
		if (!try_module_get(THIS_MODULE)) {
			printk(KERN_WARNING "LTT : Can't lock transport module.\n");
			goto error;
		}
		chan->backend.priv_ops = &lttng_relay_transport.ops;
		chan->backend.release_priv_ops = release_priv_ops;
	}
	return chan;

error:
	lttng_channel_destroy(chan);
	return NULL;
}

static
struct lib_ring_buffer *lttng_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 lttng_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 lttng_buffer_read_close(struct lib_ring_buffer *buf)
{
	lib_ring_buffer_release_read(buf);
}

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

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

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

static
void lttng_event_write_from_user(struct lib_ring_buffer_ctx *ctx,
			       const void __user *src, size_t len)
{
	lib_ring_buffer_copy_from_user_inatomic(&client_config, ctx, src, len);
}

static
void lttng_event_memset(struct lib_ring_buffer_ctx *ctx,
		int c, size_t len)
{
	lib_ring_buffer_memset(&client_config, ctx, c, len);
}

static
void lttng_event_strcpy(struct lib_ring_buffer_ctx *ctx, const char *src,
		size_t len)
{
	lib_ring_buffer_strcpy(&client_config, ctx, src, len, '#');
}

static
size_t lttng_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 *lttng_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 *lttng_get_hp_wait_queue(struct channel *chan)
{
	return &chan->hp_wait;
}

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

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

static struct lttng_transport lttng_relay_transport = {
	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
	.owner = THIS_MODULE,
	.ops = {
		.channel_create = _channel_create,
		.channel_destroy = lttng_channel_destroy,
		.buffer_read_open = lttng_buffer_read_open,
		.buffer_has_read_closed_stream =
			lttng_buffer_has_read_closed_stream,
		.buffer_read_close = lttng_buffer_read_close,
		.event_reserve = lttng_event_reserve,
		.event_commit = lttng_event_commit,
		.event_write_from_user = lttng_event_write_from_user,
		.event_memset = lttng_event_memset,
		.event_write = lttng_event_write,
		.event_strcpy = lttng_event_strcpy,
		.packet_avail_size = lttng_packet_avail_size,
		.get_writer_buf_wait_queue = lttng_get_writer_buf_wait_queue,
		.get_hp_wait_queue = lttng_get_hp_wait_queue,
		.is_finalized = lttng_is_finalized,
		.is_disabled = lttng_is_disabled,
		.timestamp_begin = client_timestamp_begin,
		.timestamp_end = client_timestamp_end,
		.events_discarded = client_events_discarded,
		.content_size = client_content_size,
		.packet_size = client_packet_size,
		.stream_id = client_stream_id,
		.current_timestamp = client_current_timestamp,
	},
};

static int __init lttng_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();
	lttng_transport_register(&lttng_relay_transport);
	return 0;
}

module_init(lttng_ring_buffer_client_init);

static void __exit lttng_ring_buffer_client_exit(void)
{
	lttng_transport_unregister(&lttng_relay_transport);
}

module_exit(lttng_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	1	/*
a90917c3	2	* lttng-ring-buffer-client.h
881833e3	3	*
881833e3 MD	4	* LTTng lib ring buffer client template.
881833e3 MD	5	*
886d51a3 MD	6	* Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	7	*
	8	* This library is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU Lesser General Public
	10	* License as published by the Free Software Foundation; only
	11	* version 2.1 of the License.
	12	*
	13	* This library is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* Lesser General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU Lesser General Public
	19	* License along with this library; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
881833e3 MD	21	*/
	22
	23	#include <linux/module.h>
	24	#include <linux/types.h>
	25	#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
a90917c3 MD	26	#include "lttng-events.h"
a90917c3 MD	27	#include "lttng-tracer.h"
881833e3	28
dd5a0db3 MD	29	static struct lttng_transport lttng_relay_transport;
dd5a0db3 MD	30
881833e3 MD	31	struct metadata_packet_header {
881833e3 MD	32	uint32_t magic; /* 0x75D11D57 */
1ec3f75a	33	uint8_t uuid[16]; /* Unique Universal Identifier */
881833e3 MD	34	uint32_t checksum; /* 0 if unused */
	35	uint32_t content_size; /* in bits */
	36	uint32_t packet_size; /* in bits */
	37	uint8_t compression_scheme; /* 0 if unused */
	38	uint8_t encryption_scheme; /* 0 if unused */
	39	uint8_t checksum_scheme; /* 0 if unused */
4173df96 MD	40	uint8_t major; /* CTF spec major version number */
4173df96 MD	41	uint8_t minor; /* CTF spec minor version number */
881833e3 MD	42	uint8_t header_end[0];
	43	};
	44
	45	struct metadata_record_header {
	46	uint8_t header_end[0]; /* End of header */
	47	};
	48
	49	static const struct lib_ring_buffer_config client_config;
	50
	51	static inline
	52	u64 lib_ring_buffer_clock_read(struct channel *chan)
	53	{
	54	return 0;
	55	}
	56
	57	static inline
	58	unsigned char record_header_size(const struct lib_ring_buffer_config *config,
	59	struct channel *chan, size_t offset,
64c796d8	60	size_t *pre_header_padding,
881833e3 MD	61	struct lib_ring_buffer_ctx *ctx)
	62	{
	63	return 0;
	64	}
	65
	66	#include "wrapper/ringbuffer/api.h"
	67
	68	static u64 client_ring_buffer_clock_read(struct channel *chan)
	69	{
	70	return 0;
	71	}
	72
	73	static
	74	size_t client_record_header_size(const struct lib_ring_buffer_config *config,
	75	struct channel *chan, size_t offset,
881833e3	76	size_t *pre_header_padding,
881833e3 MD	77	struct lib_ring_buffer_ctx *ctx)
	78	{
	79	return 0;
	80	}
	81
	82	/**
	83	* client_packet_header_size - called on buffer-switch to a new sub-buffer
	84	*
	85	* Return header size without padding after the structure. Don't use packed
	86	* structure because gcc generates inefficient code on some architectures
	87	* (powerpc, mips..)
	88	*/
	89	static size_t client_packet_header_size(void)
	90	{
	91	return offsetof(struct metadata_packet_header, header_end);
	92	}
	93
	94	static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
	95	unsigned int subbuf_idx)
	96	{
	97	struct channel *chan = buf->backend.chan;
	98	struct metadata_packet_header *header =
	99	(struct metadata_packet_header *)
	100	lib_ring_buffer_offset_address(&buf->backend,
	101	subbuf_idx * chan->backend.subbuf_size);
9b8e91ac MD	102	struct lttng_metadata_cache *metadata_cache =
9b8e91ac MD	103	channel_get_private(chan);
881833e3 MD	104
881833e3 MD	105	header->magic = TSDL_MAGIC_NUMBER;
9b8e91ac MD	106	memcpy(header->uuid, metadata_cache->uuid.b,
9b8e91ac MD	107	sizeof(metadata_cache->uuid));
881833e3 MD	108	header->checksum = 0; /* 0 if unused */
	109	header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
	110	header->packet_size = 0xFFFFFFFF; /* in bits, for debugging */
	111	header->compression_scheme = 0; /* 0 if unused */
	112	header->encryption_scheme = 0; /* 0 if unused */
	113	header->checksum_scheme = 0; /* 0 if unused */
4173df96 MD	114	header->major = CTF_SPEC_MAJOR;
4173df96 MD	115	header->minor = CTF_SPEC_MINOR;
881833e3 MD	116	}
	117
	118	/*
	119	* offset is assumed to never be 0 here : never deliver a completely empty
	120	* subbuffer. data_size is between 1 and subbuf_size.
	121	*/
	122	static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
	123	unsigned int subbuf_idx, unsigned long data_size)
	124	{
	125	struct channel *chan = buf->backend.chan;
d793d5e1	126	struct metadata_packet_header *header =
1ec3f75a	127	(struct metadata_packet_header *)
881833e3 MD	128	lib_ring_buffer_offset_address(&buf->backend,
	129	subbuf_idx * chan->backend.subbuf_size);
	130	unsigned long records_lost = 0;
	131
	132	header->content_size = data_size * CHAR_BIT; /* in bits */
	133	header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
71c1d843 MD	134	/*
	135	* We do not care about the records lost count, because the metadata
	136	* channel waits and retry.
	137	*/
	138	(void) lib_ring_buffer_get_records_lost_full(&client_config, buf);
881833e3 MD	139	records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
	140	records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
	141	WARN_ON_ONCE(records_lost != 0);
	142	}
	143
	144	static int client_buffer_create(struct lib_ring_buffer buf, void priv,
	145	int cpu, const char *name)
	146	{
	147	return 0;
	148	}
	149
	150	static void client_buffer_finalize(struct lib_ring_buffer buf, void priv, int cpu)
	151	{
	152	}
	153
3b731ab1 JD	154	static int client_timestamp_begin(const struct lib_ring_buffer_config *config,
	155	struct lib_ring_buffer buf, uint64_t timestamp_begin)
	156	{
	157	return -ENOSYS;
	158	}
	159
	160	static int client_timestamp_end(const struct lib_ring_buffer_config *config,
	161	struct lib_ring_buffer *bufb,
	162	uint64_t *timestamp_end)
	163	{
	164	return -ENOSYS;
	165	}
	166
	167	static int client_events_discarded(const struct lib_ring_buffer_config *config,
	168	struct lib_ring_buffer *bufb,
	169	uint64_t *events_discarded)
	170	{
	171	return -ENOSYS;
	172	}
	173
2348ca17 JD	174	static int client_current_timestamp(const struct lib_ring_buffer_config *config,
	175	struct lib_ring_buffer *bufb,
	176	uint64_t *ts)
	177	{
	178	return -ENOSYS;
	179	}
	180
3b731ab1 JD	181	static int client_content_size(const struct lib_ring_buffer_config *config,
	182	struct lib_ring_buffer *bufb,
	183	uint64_t *content_size)
	184	{
	185	return -ENOSYS;
	186	}
	187
	188	static int client_packet_size(const struct lib_ring_buffer_config *config,
	189	struct lib_ring_buffer *bufb,
	190	uint64_t *packet_size)
	191	{
	192	return -ENOSYS;
	193	}
	194
	195	static int client_stream_id(const struct lib_ring_buffer_config *config,
	196	struct lib_ring_buffer *bufb,
	197	uint64_t *stream_id)
	198	{
	199	return -ENOSYS;
	200	}
	201
881833e3 MD	202	static const struct lib_ring_buffer_config client_config = {
	203	.cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
	204	.cb.record_header_size = client_record_header_size,
	205	.cb.subbuffer_header_size = client_packet_header_size,
	206	.cb.buffer_begin = client_buffer_begin,
	207	.cb.buffer_end = client_buffer_end,
	208	.cb.buffer_create = client_buffer_create,
	209	.cb.buffer_finalize = client_buffer_finalize,
	210
	211	.tsc_bits = 0,
	212	.alloc = RING_BUFFER_ALLOC_GLOBAL,
	213	.sync = RING_BUFFER_SYNC_GLOBAL,
	214	.mode = RING_BUFFER_MODE_TEMPLATE,
	215	.backend = RING_BUFFER_PAGE,
2db1399a	216	.output = RING_BUFFER_OUTPUT_TEMPLATE,
881833e3 MD	217	.oops = RING_BUFFER_OOPS_CONSISTENCY,
	218	.ipi = RING_BUFFER_IPI_BARRIER,
	219	.wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
	220	};
	221
dd5a0db3 MD	222	static
	223	void release_priv_ops(void *priv_ops)
	224	{
	225	module_put(THIS_MODULE);
	226	}
	227
	228	static
	229	void lttng_channel_destroy(struct channel *chan)
	230	{
	231	channel_destroy(chan);
	232	}
	233
881833e3 MD	234	static
881833e3 MD	235	struct channel _channel_create(const char name,
a90917c3	236	struct lttng_channel lttng_chan, void buf_addr,
881833e3 MD	237	size_t subbuf_size, size_t num_subbuf,
	238	unsigned int switch_timer_interval,
	239	unsigned int read_timer_interval)
	240	{
dd5a0db3 MD	241	struct channel *chan;
dd5a0db3 MD	242
9b8e91ac MD	243	chan = channel_create(&client_config, name,
9b8e91ac MD	244	lttng_chan->session->metadata_cache, buf_addr,
881833e3 MD	245	subbuf_size, num_subbuf, switch_timer_interval,
881833e3 MD	246	read_timer_interval);
dd5a0db3 MD	247	if (chan) {
	248	/*
	249	* Ensure this module is not unloaded before we finish
	250	* using lttng_relay_transport.ops.
	251	*/
	252	if (!try_module_get(THIS_MODULE)) {
	253	printk(KERN_WARNING "LTT : Can't lock transport module.\n");
	254	goto error;
	255	}
	256	chan->backend.priv_ops = &lttng_relay_transport.ops;
	257	chan->backend.release_priv_ops = release_priv_ops;
	258	}
	259	return chan;
881833e3	260
dd5a0db3 MD	261	error:
	262	lttng_channel_destroy(chan);
	263	return NULL;
881833e3 MD	264	}
	265
	266	static
a90917c3	267	struct lib_ring_buffer lttng_buffer_read_open(struct channel chan)
881833e3 MD	268	{
881833e3 MD	269	struct lib_ring_buffer *buf;
881833e3	270
cd4bd11f MD	271	buf = channel_get_ring_buffer(&client_config, chan, 0);
	272	if (!lib_ring_buffer_open_read(buf))
	273	return buf;
881833e3 MD	274	return NULL;
	275	}
	276
f71ecafa	277	static
a90917c3	278	int lttng_buffer_has_read_closed_stream(struct channel *chan)
f71ecafa MD	279	{
	280	struct lib_ring_buffer *buf;
	281	int cpu;
	282
	283	for_each_channel_cpu(cpu, chan) {
	284	buf = channel_get_ring_buffer(&client_config, chan, cpu);
	285	if (!atomic_long_read(&buf->active_readers))
	286	return 1;
	287	}
	288	return 0;
	289	}
	290
881833e3	291	static
a90917c3	292	void lttng_buffer_read_close(struct lib_ring_buffer *buf)
881833e3 MD	293	{
881833e3 MD	294	lib_ring_buffer_release_read(buf);
881833e3 MD	295	}
881833e3 MD	296
c099397a	297	static
a90917c3	298	int lttng_event_reserve(struct lib_ring_buffer_ctx *ctx, uint32_t event_id)
881833e3 MD	299	{
	300	return lib_ring_buffer_reserve(&client_config, ctx);
	301	}
	302
c099397a	303	static
a90917c3	304	void lttng_event_commit(struct lib_ring_buffer_ctx *ctx)
881833e3 MD	305	{
	306	lib_ring_buffer_commit(&client_config, ctx);
	307	}
	308
c099397a	309	static
a90917c3	310	void lttng_event_write(struct lib_ring_buffer_ctx ctx, const void src,
881833e3 MD	311	size_t len)
	312	{
	313	lib_ring_buffer_write(&client_config, ctx, src, len);
	314	}
	315
4ea00e4f	316	static
a90917c3	317	void lttng_event_write_from_user(struct lib_ring_buffer_ctx *ctx,
4ea00e4f JD	318	const void __user *src, size_t len)
4ea00e4f JD	319	{
7b8ea3a5	320	lib_ring_buffer_copy_from_user_inatomic(&client_config, ctx, src, len);
4ea00e4f JD	321	}
4ea00e4f JD	322
58aa5d24	323	static
a90917c3	324	void lttng_event_memset(struct lib_ring_buffer_ctx *ctx,
58aa5d24 MD	325	int c, size_t len)
	326	{
	327	lib_ring_buffer_memset(&client_config, ctx, c, len);
	328	}
	329
16f78f3a MD	330	static
	331	void lttng_event_strcpy(struct lib_ring_buffer_ctx ctx, const char src,
	332	size_t len)
	333	{
	334	lib_ring_buffer_strcpy(&client_config, ctx, src, len, '#');
	335	}
	336
1ec3f75a	337	static
a90917c3	338	size_t lttng_packet_avail_size(struct channel *chan)
1ec3f75a MD	339
	340	{
	341	unsigned long o_begin;
	342	struct lib_ring_buffer *buf;
	343
	344	buf = chan->backend.buf; /* Only for global buffer ! */
	345	o_begin = v_read(&client_config, &buf->offset);
	346	if (subbuf_offset(o_begin, chan) != 0) {
	347	return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
	348	} else {
	349	return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
	350	- sizeof(struct metadata_packet_header);
	351	}
	352	}
	353
c099397a	354	static
a90917c3	355	wait_queue_head_t lttng_get_writer_buf_wait_queue(struct channel chan, int cpu)
c099397a	356	{
71c1d843 MD	357	struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config,
	358	chan, cpu);
	359	return &buf->write_wait;
24cedcfe MD	360	}
	361
	362	static
a90917c3	363	wait_queue_head_t lttng_get_hp_wait_queue(struct channel chan)
24cedcfe MD	364	{
	365	return &chan->hp_wait;
	366	}
	367
	368	static
a90917c3	369	int lttng_is_finalized(struct channel *chan)
24cedcfe MD	370	{
24cedcfe MD	371	return lib_ring_buffer_channel_is_finalized(chan);
c099397a MD	372	}
c099397a MD	373
254ec7bc	374	static
a90917c3	375	int lttng_is_disabled(struct channel *chan)
254ec7bc MD	376	{
	377	return lib_ring_buffer_channel_is_disabled(chan);
	378	}
	379
a90917c3	380	static struct lttng_transport lttng_relay_transport = {
881833e3 MD	381	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
	382	.owner = THIS_MODULE,
	383	.ops = {
	384	.channel_create = _channel_create,
a90917c3 MD	385	.channel_destroy = lttng_channel_destroy,
a90917c3 MD	386	.buffer_read_open = lttng_buffer_read_open,
f71ecafa	387	.buffer_has_read_closed_stream =
a90917c3 MD	388	lttng_buffer_has_read_closed_stream,
	389	.buffer_read_close = lttng_buffer_read_close,
	390	.event_reserve = lttng_event_reserve,
	391	.event_commit = lttng_event_commit,
	392	.event_write_from_user = lttng_event_write_from_user,
	393	.event_memset = lttng_event_memset,
	394	.event_write = lttng_event_write,
16f78f3a	395	.event_strcpy = lttng_event_strcpy,
a90917c3 MD	396	.packet_avail_size = lttng_packet_avail_size,
	397	.get_writer_buf_wait_queue = lttng_get_writer_buf_wait_queue,
	398	.get_hp_wait_queue = lttng_get_hp_wait_queue,
	399	.is_finalized = lttng_is_finalized,
	400	.is_disabled = lttng_is_disabled,
67a80835 MD	401	.timestamp_begin = client_timestamp_begin,
	402	.timestamp_end = client_timestamp_end,
	403	.events_discarded = client_events_discarded,
	404	.content_size = client_content_size,
	405	.packet_size = client_packet_size,
	406	.stream_id = client_stream_id,
	407	.current_timestamp = client_current_timestamp,
881833e3 MD	408	},
	409	};
	410
a90917c3	411	static int __init lttng_ring_buffer_client_init(void)
881833e3 MD	412	{
	413	/*
	414	* This vmalloc sync all also takes care of the lib ring buffer
	415	* vmalloc'd module pages when it is built as a module into LTTng.
	416	*/
	417	wrapper_vmalloc_sync_all();
a90917c3	418	lttng_transport_register(&lttng_relay_transport);
881833e3 MD	419	return 0;
	420	}
	421
a90917c3	422	module_init(lttng_ring_buffer_client_init);
881833e3	423
a90917c3	424	static void __exit lttng_ring_buffer_client_exit(void)
881833e3	425	{
a90917c3	426	lttng_transport_unregister(&lttng_relay_transport);
881833e3 MD	427	}
881833e3 MD	428
a90917c3	429	module_exit(lttng_ring_buffer_client_exit);
881833e3 MD	430
	431	MODULE_LICENSE("GPL and additional rights");
	432	MODULE_AUTHOR("Mathieu Desnoyers");
	433	MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
	434	" client");