[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"

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_channel *lttng_chan = channel_get_private(chan);
	struct lttng_session *session = lttng_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 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
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)
{
	lttng_chan->ops->timestamp_begin = client_timestamp_begin;
	lttng_chan->ops->timestamp_end = client_timestamp_end;
	lttng_chan->ops->events_discarded = client_events_discarded;
	lttng_chan->ops->content_size = client_content_size;
	lttng_chan->ops->packet_size = client_packet_size;
	lttng_chan->ops->stream_id = client_stream_id;
	lttng_chan->ops->current_timestamp = client_current_timestamp;

	return channel_create(&client_config, name, lttng_chan, buf_addr,
			      subbuf_size, num_subbuf, switch_timer_interval,
			      read_timer_interval);
}

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

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
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,
		.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,
	},
};

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