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

/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
 *
 * lttng-ring-buffer-client.h
 *
 * LTTng lib ring buffer client template.
 *
 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#include <linux/module.h>
#include <linux/types.h>
#include <wrapper/vmalloc.h>	/* for wrapper_vmalloc_sync_mappings() */
#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
size_t 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,
				 void *client_ctx)
{
	return 0;
}

#include <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,
				 void *client_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 int client_sequence_number(const struct lib_ring_buffer_config *config,
			struct lib_ring_buffer *bufb,
			uint64_t *seq)
{
	return -ENOSYS;
}

static
int client_instance_id(const struct lib_ring_buffer_config *config,
		struct lib_ring_buffer *bufb,
		uint64_t *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,
				void *priv, void *buf_addr,
				size_t subbuf_size, size_t num_subbuf,
				unsigned int switch_timer_interval,
				unsigned int read_timer_interval)
{
	struct lttng_channel *lttng_chan = priv;
	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 "LTTng: 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)
{
	struct channel *chan = ctx->client_priv;
	int ret;

	memset(&ctx->priv, 0, sizeof(ctx->priv));
	ctx->priv.chan = chan;

	ret = lib_ring_buffer_reserve(&client_config, ctx, NULL);
	if (ret)
		return ret;
	lib_ring_buffer_backend_get_pages(&client_config, ctx,
			&ctx->priv.backend_pages);
	return 0;

}

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,
		.sequence_number = client_sequence_number,
		.instance_id = client_instance_id,
	},
};

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_mappings();
	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 <mathieu.desnoyers@efficios.com>");
MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
		   " client");
MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
	__stringify(LTTNG_MODULES_MINOR_VERSION) "."
	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
	LTTNG_MODULES_EXTRAVERSION);
Commit	Line	Data
b7cdc182	1	/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
9f36eaed	2	*
a90917c3	3	* lttng-ring-buffer-client.h
881833e3	4	*
881833e3 MD	5	* LTTng lib ring buffer client template.
881833e3 MD	6	*
886d51a3	7	* Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
881833e3 MD	8	*/
	9
	10	#include <linux/module.h>
	11	#include <linux/types.h>
263b6c88	12	#include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */
2df37e95 MD	13	#include <lttng/events.h>
2df37e95 MD	14	#include <lttng/tracer.h>
881833e3	15
dd5a0db3 MD	16	static struct lttng_transport lttng_relay_transport;
dd5a0db3 MD	17
881833e3 MD	18	struct metadata_packet_header {
881833e3 MD	19	uint32_t magic; /* 0x75D11D57 */
1ec3f75a	20	uint8_t uuid[16]; /* Unique Universal Identifier */
881833e3 MD	21	uint32_t checksum; /* 0 if unused */
	22	uint32_t content_size; /* in bits */
	23	uint32_t packet_size; /* in bits */
	24	uint8_t compression_scheme; /* 0 if unused */
	25	uint8_t encryption_scheme; /* 0 if unused */
	26	uint8_t checksum_scheme; /* 0 if unused */
4173df96 MD	27	uint8_t major; /* CTF spec major version number */
4173df96 MD	28	uint8_t minor; /* CTF spec minor version number */
881833e3 MD	29	uint8_t header_end[0];
	30	};
	31
	32	struct metadata_record_header {
	33	uint8_t header_end[0]; /* End of header */
	34	};
	35
	36	static const struct lib_ring_buffer_config client_config;
	37
	38	static inline
	39	u64 lib_ring_buffer_clock_read(struct channel *chan)
	40	{
	41	return 0;
	42	}
	43
	44	static inline
c1cc82b8	45	size_t record_header_size(const struct lib_ring_buffer_config *config,
881833e3	46	struct channel *chan, size_t offset,
64c796d8	47	size_t *pre_header_padding,
cc62f29e MD	48	struct lib_ring_buffer_ctx *ctx,
cc62f29e MD	49	void *client_ctx)
881833e3 MD	50	{
	51	return 0;
	52	}
	53
24591303	54	#include <ringbuffer/api.h>
881833e3 MD	55
	56	static u64 client_ring_buffer_clock_read(struct channel *chan)
	57	{
	58	return 0;
	59	}
	60
	61	static
	62	size_t client_record_header_size(const struct lib_ring_buffer_config *config,
	63	struct channel *chan, size_t offset,
881833e3	64	size_t *pre_header_padding,
cc62f29e MD	65	struct lib_ring_buffer_ctx *ctx,
cc62f29e MD	66	void *client_ctx)
881833e3 MD	67	{
	68	return 0;
	69	}
	70
	71	/**
	72	* client_packet_header_size - called on buffer-switch to a new sub-buffer
	73	*
	74	* Return header size without padding after the structure. Don't use packed
	75	* structure because gcc generates inefficient code on some architectures
	76	* (powerpc, mips..)
	77	*/
	78	static size_t client_packet_header_size(void)
	79	{
	80	return offsetof(struct metadata_packet_header, header_end);
	81	}
	82
	83	static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
	84	unsigned int subbuf_idx)
	85	{
	86	struct channel *chan = buf->backend.chan;
	87	struct metadata_packet_header *header =
	88	(struct metadata_packet_header *)
	89	lib_ring_buffer_offset_address(&buf->backend,
	90	subbuf_idx * chan->backend.subbuf_size);
a36580d5 MD	91	struct lttng_metadata_cache *metadata_cache =
a36580d5 MD	92	channel_get_private(chan);
881833e3 MD	93
881833e3 MD	94	header->magic = TSDL_MAGIC_NUMBER;
a36580d5 MD	95	memcpy(header->uuid, metadata_cache->uuid.b,
a36580d5 MD	96	sizeof(metadata_cache->uuid));
881833e3 MD	97	header->checksum = 0; /* 0 if unused */
	98	header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
	99	header->packet_size = 0xFFFFFFFF; /* in bits, for debugging */
	100	header->compression_scheme = 0; /* 0 if unused */
	101	header->encryption_scheme = 0; /* 0 if unused */
	102	header->checksum_scheme = 0; /* 0 if unused */
4173df96 MD	103	header->major = CTF_SPEC_MAJOR;
4173df96 MD	104	header->minor = CTF_SPEC_MINOR;
881833e3 MD	105	}
	106
	107	/*
	108	* offset is assumed to never be 0 here : never deliver a completely empty
	109	* subbuffer. data_size is between 1 and subbuf_size.
	110	*/
	111	static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
	112	unsigned int subbuf_idx, unsigned long data_size)
	113	{
	114	struct channel *chan = buf->backend.chan;
d793d5e1	115	struct metadata_packet_header *header =
1ec3f75a	116	(struct metadata_packet_header *)
881833e3 MD	117	lib_ring_buffer_offset_address(&buf->backend,
	118	subbuf_idx * chan->backend.subbuf_size);
	119	unsigned long records_lost = 0;
	120
	121	header->content_size = data_size * CHAR_BIT; /* in bits */
	122	header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
71c1d843 MD	123	/*
	124	* We do not care about the records lost count, because the metadata
	125	* channel waits and retry.
	126	*/
	127	(void) lib_ring_buffer_get_records_lost_full(&client_config, buf);
881833e3 MD	128	records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
	129	records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
	130	WARN_ON_ONCE(records_lost != 0);
	131	}
	132
	133	static int client_buffer_create(struct lib_ring_buffer buf, void priv,
	134	int cpu, const char *name)
	135	{
	136	return 0;
	137	}
	138
	139	static void client_buffer_finalize(struct lib_ring_buffer buf, void priv, int cpu)
	140	{
	141	}
	142
3b731ab1 JD	143	static int client_timestamp_begin(const struct lib_ring_buffer_config *config,
	144	struct lib_ring_buffer buf, uint64_t timestamp_begin)
	145	{
	146	return -ENOSYS;
	147	}
	148
	149	static int client_timestamp_end(const struct lib_ring_buffer_config *config,
	150	struct lib_ring_buffer *bufb,
	151	uint64_t *timestamp_end)
	152	{
	153	return -ENOSYS;
	154	}
	155
	156	static int client_events_discarded(const struct lib_ring_buffer_config *config,
	157	struct lib_ring_buffer *bufb,
	158	uint64_t *events_discarded)
	159	{
	160	return -ENOSYS;
	161	}
	162
2348ca17 JD	163	static int client_current_timestamp(const struct lib_ring_buffer_config *config,
	164	struct lib_ring_buffer *bufb,
	165	uint64_t *ts)
	166	{
	167	return -ENOSYS;
	168	}
	169
3b731ab1 JD	170	static int client_content_size(const struct lib_ring_buffer_config *config,
	171	struct lib_ring_buffer *bufb,
	172	uint64_t *content_size)
	173	{
	174	return -ENOSYS;
	175	}
	176
	177	static int client_packet_size(const struct lib_ring_buffer_config *config,
	178	struct lib_ring_buffer *bufb,
	179	uint64_t *packet_size)
	180	{
	181	return -ENOSYS;
	182	}
	183
	184	static int client_stream_id(const struct lib_ring_buffer_config *config,
	185	struct lib_ring_buffer *bufb,
	186	uint64_t *stream_id)
	187	{
	188	return -ENOSYS;
	189	}
	190
5b3cf4f9 JD	191	static int client_sequence_number(const struct lib_ring_buffer_config *config,
	192	struct lib_ring_buffer *bufb,
	193	uint64_t *seq)
	194	{
	195	return -ENOSYS;
	196	}
	197
5594698f JD	198	static
	199	int client_instance_id(const struct lib_ring_buffer_config *config,
	200	struct lib_ring_buffer *bufb,
	201	uint64_t *id)
	202	{
	203	return -ENOSYS;
	204	}
	205
881833e3 MD	206	static const struct lib_ring_buffer_config client_config = {
	207	.cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
	208	.cb.record_header_size = client_record_header_size,
	209	.cb.subbuffer_header_size = client_packet_header_size,
	210	.cb.buffer_begin = client_buffer_begin,
	211	.cb.buffer_end = client_buffer_end,
	212	.cb.buffer_create = client_buffer_create,
	213	.cb.buffer_finalize = client_buffer_finalize,
	214
	215	.tsc_bits = 0,
	216	.alloc = RING_BUFFER_ALLOC_GLOBAL,
	217	.sync = RING_BUFFER_SYNC_GLOBAL,
	218	.mode = RING_BUFFER_MODE_TEMPLATE,
	219	.backend = RING_BUFFER_PAGE,
2db1399a	220	.output = RING_BUFFER_OUTPUT_TEMPLATE,
881833e3 MD	221	.oops = RING_BUFFER_OOPS_CONSISTENCY,
	222	.ipi = RING_BUFFER_IPI_BARRIER,
	223	.wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
	224	};
	225
dd5a0db3 MD	226	static
	227	void release_priv_ops(void *priv_ops)
	228	{
	229	module_put(THIS_MODULE);
	230	}
	231
	232	static
	233	void lttng_channel_destroy(struct channel *chan)
	234	{
	235	channel_destroy(chan);
	236	}
	237
881833e3 MD	238	static
881833e3 MD	239	struct channel _channel_create(const char name,
5cf4b87c	240	void priv, void buf_addr,
881833e3 MD	241	size_t subbuf_size, size_t num_subbuf,
	242	unsigned int switch_timer_interval,
	243	unsigned int read_timer_interval)
	244	{
5cf4b87c	245	struct lttng_channel *lttng_chan = priv;
dd5a0db3 MD	246	struct channel *chan;
dd5a0db3 MD	247
a36580d5 MD	248	chan = channel_create(&client_config, name,
a36580d5 MD	249	lttng_chan->session->metadata_cache, buf_addr,
881833e3 MD	250	subbuf_size, num_subbuf, switch_timer_interval,
881833e3 MD	251	read_timer_interval);
dd5a0db3 MD	252	if (chan) {
	253	/*
	254	* Ensure this module is not unloaded before we finish
	255	* using lttng_relay_transport.ops.
	256	*/
	257	if (!try_module_get(THIS_MODULE)) {
5a15f70c	258	printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
dd5a0db3 MD	259	goto error;
	260	}
	261	chan->backend.priv_ops = &lttng_relay_transport.ops;
	262	chan->backend.release_priv_ops = release_priv_ops;
	263	}
	264	return chan;
881833e3	265
dd5a0db3 MD	266	error:
	267	lttng_channel_destroy(chan);
	268	return NULL;
881833e3 MD	269	}
	270
	271	static
a90917c3	272	struct lib_ring_buffer lttng_buffer_read_open(struct channel chan)
881833e3 MD	273	{
881833e3 MD	274	struct lib_ring_buffer *buf;
881833e3	275
cd4bd11f MD	276	buf = channel_get_ring_buffer(&client_config, chan, 0);
	277	if (!lib_ring_buffer_open_read(buf))
	278	return buf;
881833e3 MD	279	return NULL;
	280	}
	281
f71ecafa	282	static
a90917c3	283	int lttng_buffer_has_read_closed_stream(struct channel *chan)
f71ecafa MD	284	{
	285	struct lib_ring_buffer *buf;
	286	int cpu;
	287
	288	for_each_channel_cpu(cpu, chan) {
	289	buf = channel_get_ring_buffer(&client_config, chan, cpu);
	290	if (!atomic_long_read(&buf->active_readers))
	291	return 1;
	292	}
	293	return 0;
	294	}
	295
881833e3	296	static
a90917c3	297	void lttng_buffer_read_close(struct lib_ring_buffer *buf)
881833e3 MD	298	{
881833e3 MD	299	lib_ring_buffer_release_read(buf);
881833e3 MD	300	}
881833e3 MD	301
c099397a	302	static
c2fb9c1c	303	int lttng_event_reserve(struct lib_ring_buffer_ctx *ctx)
881833e3	304	{
b1199bd3	305	struct channel *chan = ctx->client_priv;
85a07c33 MD	306	int ret;
85a07c33 MD	307
b1199bd3 MD	308	memset(&ctx->priv, 0, sizeof(ctx->priv));
	309	ctx->priv.chan = chan;
	310
cc62f29e	311	ret = lib_ring_buffer_reserve(&client_config, ctx, NULL);
85a07c33 MD	312	if (ret)
	313	return ret;
	314	lib_ring_buffer_backend_get_pages(&client_config, ctx,
b1199bd3	315	&ctx->priv.backend_pages);
85a07c33 MD	316	return 0;
85a07c33 MD	317
881833e3 MD	318	}
881833e3 MD	319
c099397a	320	static
a90917c3	321	void lttng_event_commit(struct lib_ring_buffer_ctx *ctx)
881833e3 MD	322	{
	323	lib_ring_buffer_commit(&client_config, ctx);
	324	}
	325
c099397a	326	static
a90917c3	327	void lttng_event_write(struct lib_ring_buffer_ctx ctx, const void src,
881833e3 MD	328	size_t len)
	329	{
	330	lib_ring_buffer_write(&client_config, ctx, src, len);
	331	}
	332
4ea00e4f	333	static
a90917c3	334	void lttng_event_write_from_user(struct lib_ring_buffer_ctx *ctx,
4ea00e4f JD	335	const void __user *src, size_t len)
4ea00e4f JD	336	{
7b8ea3a5	337	lib_ring_buffer_copy_from_user_inatomic(&client_config, ctx, src, len);
4ea00e4f JD	338	}
4ea00e4f JD	339
58aa5d24	340	static
a90917c3	341	void lttng_event_memset(struct lib_ring_buffer_ctx *ctx,
58aa5d24 MD	342	int c, size_t len)
	343	{
	344	lib_ring_buffer_memset(&client_config, ctx, c, len);
	345	}
	346
16f78f3a MD	347	static
	348	void lttng_event_strcpy(struct lib_ring_buffer_ctx ctx, const char src,
	349	size_t len)
	350	{
	351	lib_ring_buffer_strcpy(&client_config, ctx, src, len, '#');
	352	}
	353
1ec3f75a	354	static
a90917c3	355	size_t lttng_packet_avail_size(struct channel *chan)
1ec3f75a MD	356	{
	357	unsigned long o_begin;
	358	struct lib_ring_buffer *buf;
	359
	360	buf = chan->backend.buf; /* Only for global buffer ! */
	361	o_begin = v_read(&client_config, &buf->offset);
	362	if (subbuf_offset(o_begin, chan) != 0) {
	363	return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
	364	} else {
	365	return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
	366	- sizeof(struct metadata_packet_header);
	367	}
	368	}
	369
c099397a	370	static
a90917c3	371	wait_queue_head_t lttng_get_writer_buf_wait_queue(struct channel chan, int cpu)
c099397a	372	{
71c1d843 MD	373	struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config,
	374	chan, cpu);
	375	return &buf->write_wait;
24cedcfe MD	376	}
	377
	378	static
a90917c3	379	wait_queue_head_t lttng_get_hp_wait_queue(struct channel chan)
24cedcfe MD	380	{
	381	return &chan->hp_wait;
	382	}
	383
	384	static
a90917c3	385	int lttng_is_finalized(struct channel *chan)
24cedcfe MD	386	{
24cedcfe MD	387	return lib_ring_buffer_channel_is_finalized(chan);
c099397a MD	388	}
c099397a MD	389
254ec7bc	390	static
a90917c3	391	int lttng_is_disabled(struct channel *chan)
254ec7bc MD	392	{
	393	return lib_ring_buffer_channel_is_disabled(chan);
	394	}
	395
a90917c3	396	static struct lttng_transport lttng_relay_transport = {
881833e3 MD	397	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
	398	.owner = THIS_MODULE,
	399	.ops = {
	400	.channel_create = _channel_create,
a90917c3 MD	401	.channel_destroy = lttng_channel_destroy,
a90917c3 MD	402	.buffer_read_open = lttng_buffer_read_open,
f71ecafa	403	.buffer_has_read_closed_stream =
a90917c3 MD	404	lttng_buffer_has_read_closed_stream,
	405	.buffer_read_close = lttng_buffer_read_close,
	406	.event_reserve = lttng_event_reserve,
	407	.event_commit = lttng_event_commit,
	408	.event_write_from_user = lttng_event_write_from_user,
	409	.event_memset = lttng_event_memset,
	410	.event_write = lttng_event_write,
16f78f3a	411	.event_strcpy = lttng_event_strcpy,
a90917c3 MD	412	.packet_avail_size = lttng_packet_avail_size,
	413	.get_writer_buf_wait_queue = lttng_get_writer_buf_wait_queue,
	414	.get_hp_wait_queue = lttng_get_hp_wait_queue,
	415	.is_finalized = lttng_is_finalized,
	416	.is_disabled = lttng_is_disabled,
67a80835 MD	417	.timestamp_begin = client_timestamp_begin,
	418	.timestamp_end = client_timestamp_end,
	419	.events_discarded = client_events_discarded,
	420	.content_size = client_content_size,
	421	.packet_size = client_packet_size,
	422	.stream_id = client_stream_id,
	423	.current_timestamp = client_current_timestamp,
5b3cf4f9	424	.sequence_number = client_sequence_number,
5594698f	425	.instance_id = client_instance_id,
881833e3 MD	426	},
	427	};
	428
a90917c3	429	static int __init lttng_ring_buffer_client_init(void)
881833e3 MD	430	{
	431	/*
	432	* This vmalloc sync all also takes care of the lib ring buffer
	433	* vmalloc'd module pages when it is built as a module into LTTng.
	434	*/
263b6c88	435	wrapper_vmalloc_sync_mappings();
a90917c3	436	lttng_transport_register(&lttng_relay_transport);
881833e3 MD	437	return 0;
	438	}
	439
a90917c3	440	module_init(lttng_ring_buffer_client_init);
881833e3	441
a90917c3	442	static void __exit lttng_ring_buffer_client_exit(void)
881833e3	443	{
a90917c3	444	lttng_transport_unregister(&lttng_relay_transport);
881833e3 MD	445	}
881833e3 MD	446
a90917c3	447	module_exit(lttng_ring_buffer_client_exit);
881833e3 MD	448
881833e3 MD	449	MODULE_LICENSE("GPL and additional rights");
1c124020	450	MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
881833e3 MD	451	MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
881833e3 MD	452	" client");
1c124020 MJ	453	MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
	454	__stringify(LTTNG_MODULES_MINOR_VERSION) "."
	455	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
	456	LTTNG_MODULES_EXTRAVERSION);