[lttng-modules.git] / ltt-ring-buffer-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 "lib/bitfield.h"
#include "wrapper/vmalloc.h"	/* for wrapper_vmalloc_sync_all() */
#include "wrapper/trace-clock.h"
#include "ltt-events.h"
#include "ltt-tracer.h"
#include "wrapper/ringbuffer/frontend_types.h"

/*
 * Keep the natural field alignment for _each field_ within this structure if
 * you ever add/remove a field from this header. Packed attribute is not used
 * because gcc generates poor code on at least powerpc and mips. Don't ever
 * let gcc add padding between the structure elements.
 *
 * The guarantee we have with timestamps is that all the events in a
 * packet are included (inclusive) within the begin/end timestamps of
 * the packet. Another guarantee we have is that the "timestamp begin",
 * as well as the event timestamps, are monotonically increasing (never
 * decrease) when moving forward in a stream (physically). But this
 * guarantee does not apply to "timestamp end", because it is sampled at
 * commit time, which is not ordered with respect to space reservation.
 */

struct packet_header {
	/* Trace packet header */
	uint32_t magic;			/*
					 * Trace magic number.
					 * contains endianness information.
					 */
	uint8_t uuid[16];
	uint32_t stream_id;

	struct {
		/* Stream packet context */
		uint64_t timestamp_begin;	/* Cycle count at subbuffer start */
		uint64_t timestamp_end;		/* Cycle count at subbuffer end */
		uint32_t events_discarded;	/*
						 * Events lost in this subbuffer since
						 * the beginning of the trace.
						 * (may overflow)
						 */
		uint32_t content_size;		/* Size of data in subbuffer */
		uint32_t packet_size;		/* Subbuffer size (include padding) */
		uint32_t cpu_id;		/* CPU id associated with stream */
		uint8_t header_end;		/* End of header */
	} ctx;
};


static inline notrace u64 lib_ring_buffer_clock_read(struct channel *chan)
{
	return trace_clock_read64();
}

static inline
size_t ctx_get_size(size_t offset, struct lttng_ctx *ctx)
{
	int i;
	size_t orig_offset = offset;

	if (likely(!ctx))
		return 0;
	for (i = 0; i < ctx->nr_fields; i++)
		offset += ctx->fields[i].get_size(offset);
	return offset - orig_offset;
}

static inline
void ctx_record(struct lib_ring_buffer_ctx *bufctx,
		struct ltt_channel *chan,
		struct lttng_ctx *ctx)
{
	int i;

	if (likely(!ctx))
		return;
	for (i = 0; i < ctx->nr_fields; i++)
		ctx->fields[i].record(&ctx->fields[i], bufctx, chan);
}

/*
 * record_header_size - Calculate the header size and padding necessary.
 * @config: ring buffer instance configuration
 * @chan: channel
 * @offset: offset in the write buffer
 * @pre_header_padding: padding to add before the header (output)
 * @ctx: reservation context
 *
 * Returns the event header size (including padding).
 *
 * The payload must itself determine its own alignment from the biggest type it
 * contains.
 */
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)
{
	struct ltt_channel *ltt_chan = channel_get_private(chan);
	struct ltt_event *event = ctx->priv;
	size_t orig_offset = offset;
	size_t padding;

	switch (ltt_chan->header_type) {
	case 1:	/* compact */
		padding = lib_ring_buffer_align(offset, ltt_alignof(uint32_t));
		offset += padding;
		if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTT_RFLAG_EXTENDED))) {
			offset += sizeof(uint32_t);	/* id and timestamp */
		} else {
			/* Minimum space taken by 5-bit id */
			offset += sizeof(uint8_t);
			/* Align extended struct on largest member */
			offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
			offset += sizeof(uint32_t);	/* id */
			offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
			offset += sizeof(uint64_t);	/* timestamp */
		}
		break;
	case 2:	/* large */
		padding = lib_ring_buffer_align(offset, ltt_alignof(uint16_t));
		offset += padding;
		offset += sizeof(uint16_t);
		if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTT_RFLAG_EXTENDED))) {
			offset += lib_ring_buffer_align(offset, ltt_alignof(uint32_t));
			offset += sizeof(uint32_t);	/* timestamp */
		} else {
			/* Align extended struct on largest member */
			offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
			offset += sizeof(uint32_t);	/* id */
			offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
			offset += sizeof(uint64_t);	/* timestamp */
		}
		break;
	default:
		padding = 0;
		WARN_ON_ONCE(1);
	}
	offset += ctx_get_size(offset, event->ctx);
	offset += ctx_get_size(offset, ltt_chan->ctx);

	*pre_header_padding = padding;
	return offset - orig_offset;
}

#include "wrapper/ringbuffer/api.h"

static
void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
				 struct lib_ring_buffer_ctx *ctx,
				 uint32_t event_id);

/*
 * ltt_write_event_header
 *
 * Writes the event header to the offset (already aligned on 32-bits).
 *
 * @config: ring buffer instance configuration
 * @ctx: reservation context
 * @event_id: event ID
 */
static __inline__
void ltt_write_event_header(const struct lib_ring_buffer_config *config,
			    struct lib_ring_buffer_ctx *ctx,
			    uint32_t event_id)
{
	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
	struct ltt_event *event = ctx->priv;

	if (unlikely(ctx->rflags))
		goto slow_path;

	switch (ltt_chan->header_type) {
	case 1:	/* compact */
	{
		uint32_t id_time = 0;

		bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
		bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
		lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
		break;
	}
	case 2:	/* large */
	{
		uint32_t timestamp = (uint32_t) ctx->tsc;
		uint16_t id = event_id;

		lib_ring_buffer_write(config, ctx, &id, sizeof(id));
		lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t));
		lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
		break;
	}
	default:
		WARN_ON_ONCE(1);
	}

	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
	ctx_record(ctx, ltt_chan, event->ctx);
	lib_ring_buffer_align_ctx(ctx, ctx->largest_align);

	return;

slow_path:
	ltt_write_event_header_slow(config, ctx, event_id);
}

static
void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
				 struct lib_ring_buffer_ctx *ctx,
				 uint32_t event_id)
{
	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
	struct ltt_event *event = ctx->priv;

	switch (ltt_chan->header_type) {
	case 1:	/* compact */
		if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTT_RFLAG_EXTENDED))) {
			uint32_t id_time = 0;

			bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
			bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
			lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
		} else {
			uint8_t id = 0;
			uint64_t timestamp = ctx->tsc;

			bt_bitfield_write(&id, uint8_t, 0, 5, 31);
			lib_ring_buffer_write(config, ctx, &id, sizeof(id));
			/* Align extended struct on largest member */
			lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
			lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
			lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
			lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
		}
		break;
	case 2:	/* large */
	{
		if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTT_RFLAG_EXTENDED))) {
			uint32_t timestamp = (uint32_t) ctx->tsc;
			uint16_t id = event_id;

			lib_ring_buffer_write(config, ctx, &id, sizeof(id));
			lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t));
			lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
		} else {
			uint16_t id = 65535;
			uint64_t timestamp = ctx->tsc;

			lib_ring_buffer_write(config, ctx, &id, sizeof(id));
			/* Align extended struct on largest member */
			lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
			lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
			lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
			lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
		}
		break;
	}
	default:
		WARN_ON_ONCE(1);
	}
	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
	ctx_record(ctx, ltt_chan, event->ctx);
	lib_ring_buffer_align_ctx(ctx, ctx->largest_align);
}

static const struct lib_ring_buffer_config client_config;

static u64 client_ring_buffer_clock_read(struct channel *chan)
{
	return lib_ring_buffer_clock_read(chan);
}

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 record_header_size(config, chan, offset,
				  pre_header_padding, ctx);
}

/**
 * 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 packet_header, ctx.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 packet_header *header =
		(struct 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 = CTF_MAGIC_NUMBER;
	memcpy(header->uuid, session->uuid.b, sizeof(session->uuid));
	header->stream_id = ltt_chan->id;
	header->ctx.timestamp_begin = tsc;
	header->ctx.timestamp_end = 0;
	header->ctx.events_discarded = 0;
	header->ctx.content_size = 0xFFFFFFFF; /* for debugging */
	header->ctx.packet_size = 0xFFFFFFFF;
	header->ctx.cpu_id = buf->backend.cpu;
}

/*
 * 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 packet_header *header =
		(struct packet_header *)
			lib_ring_buffer_offset_address(&buf->backend,
				subbuf_idx * chan->backend.subbuf_size);
	unsigned long records_lost = 0;

	header->ctx.timestamp_end = tsc;
	header->ctx.content_size = data_size * CHAR_BIT; 	/* in bits */
	header->ctx.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);
	header->ctx.events_discarded = records_lost;
}

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 = 32,
	.alloc = RING_BUFFER_ALLOC_PER_CPU,
	.sync = RING_BUFFER_SYNC_PER_CPU,
	.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 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;
	int cpu;

	for_each_channel_cpu(cpu, chan) {
		buf = channel_get_ring_buffer(&client_config, chan, cpu);
		if (!lib_ring_buffer_open_read(buf))
			return buf;
	}
	return NULL;
}

static
int ltt_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 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)
{
	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
	int ret, cpu;

	cpu = lib_ring_buffer_get_cpu(&client_config);
	if (cpu < 0)
		return -EPERM;
	ctx->cpu = cpu;

	switch (ltt_chan->header_type) {
	case 1:	/* compact */
		if (event_id > 30)
			ctx->rflags |= LTT_RFLAG_EXTENDED;
		break;
	case 2:	/* large */
		if (event_id > 65534)
			ctx->rflags |= LTT_RFLAG_EXTENDED;
		break;
	default:
		WARN_ON_ONCE(1);
	}

	ret = lib_ring_buffer_reserve(&client_config, ctx);
	if (ret)
		goto put;
	ltt_write_event_header(&client_config, ctx, event_id);
	return 0;
put:
	lib_ring_buffer_put_cpu(&client_config);
	return ret;
}

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

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
wait_queue_head_t *ltt_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 *ltt_get_hp_wait_queue(struct channel *chan)
{
	return &chan->hp_wait;
}

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

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

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_has_read_closed_stream =
			ltt_buffer_has_read_closed_stream,
		.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 = NULL,	/* Would be racy anyway */
		.get_writer_buf_wait_queue = ltt_get_writer_buf_wait_queue,
		.get_hp_wait_queue = ltt_get_hp_wait_queue,
		.is_finalized = ltt_is_finalized,
		.is_disabled = ltt_is_disabled,
	},
};

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();
	ltt_transport_register(&ltt_relay_transport);
	return 0;
}

module_init(ltt_ring_buffer_client_init);

static void __exit ltt_ring_buffer_client_exit(void)
{
	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
7514523f	1	/*
3d084699	2	* ltt-ring-buffer-client.h
7514523f MD	3	*
	4	* Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	5	*
3d084699	6	* LTTng lib ring buffer client template.
7514523f MD	7	*
	8	* Dual LGPL v2.1/GPL v2 license.
	9	*/
	10
	11	#include <linux/module.h>
c0e31d2e	12	#include <linux/types.h>
9115fbdc	13	#include "lib/bitfield.h"
b13f3ebe	14	#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
f3bc08c5	15	#include "wrapper/trace-clock.h"
c0e31d2e	16	#include "ltt-events.h"
7514523f	17	#include "ltt-tracer.h"
9115fbdc	18	#include "wrapper/ringbuffer/frontend_types.h"
7514523f	19
d793d5e1 MD	20	/*
	21	* Keep the natural field alignment for _each field_ within this structure if
	22	* you ever add/remove a field from this header. Packed attribute is not used
	23	* because gcc generates poor code on at least powerpc and mips. Don't ever
	24	* let gcc add padding between the structure elements.
fcf74578 MD	25	*
	26	* The guarantee we have with timestamps is that all the events in a
	27	* packet are included (inclusive) within the begin/end timestamps of
	28	* the packet. Another guarantee we have is that the "timestamp begin",
	29	* as well as the event timestamps, are monotonically increasing (never
	30	* decrease) when moving forward in a stream (physically). But this
	31	* guarantee does not apply to "timestamp end", because it is sampled at
	32	* commit time, which is not ordered with respect to space reservation.
d793d5e1	33	*/
9115fbdc	34
d793d5e1	35	struct packet_header {
9115fbdc	36	/* Trace packet header */
d793d5e1 MD	37	uint32_t magic; /*
	38	* Trace magic number.
	39	* contains endianness information.
	40	*/
1ec3f75a	41	uint8_t uuid[16];
d793d5e1	42	uint32_t stream_id;
9115fbdc MD	43
	44	struct {
	45	/* Stream packet context */
	46	uint64_t timestamp_begin; /* Cycle count at subbuffer start */
	47	uint64_t timestamp_end; /* Cycle count at subbuffer end */
	48	uint32_t events_discarded; /*
	49	* Events lost in this subbuffer since
	50	* the beginning of the trace.
	51	* (may overflow)
	52	*/
	53	uint32_t content_size; /* Size of data in subbuffer */
	54	uint32_t packet_size; /* Subbuffer size (include padding) */
	55	uint32_t cpu_id; /* CPU id associated with stream */
	56	uint8_t header_end; /* End of header */
	57	} ctx;
d793d5e1 MD	58	};
	59
	60
881833e3 MD	61	static inline notrace u64 lib_ring_buffer_clock_read(struct channel *chan)
	62	{
	63	return trace_clock_read64();
	64	}
	65
f1676205 MD	66	static inline
	67	size_t ctx_get_size(size_t offset, struct lttng_ctx *ctx)
	68	{
	69	int i;
	70	size_t orig_offset = offset;
	71
	72	if (likely(!ctx))
	73	return 0;
	74	for (i = 0; i < ctx->nr_fields; i++)
	75	offset += ctx->fields[i].get_size(offset);
	76	return offset - orig_offset;
	77	}
	78
	79	static inline
	80	void ctx_record(struct lib_ring_buffer_ctx *bufctx,
	81	struct ltt_channel *chan,
	82	struct lttng_ctx *ctx)
	83	{
	84	int i;
	85
	86	if (likely(!ctx))
	87	return;
	88	for (i = 0; i < ctx->nr_fields; i++)
	89	ctx->fields[i].record(&ctx->fields[i], bufctx, chan);
	90	}
	91
881833e3 MD	92	/*
	93	* record_header_size - Calculate the header size and padding necessary.
	94	* @config: ring buffer instance configuration
	95	* @chan: channel
	96	* @offset: offset in the write buffer
881833e3	97	* @pre_header_padding: padding to add before the header (output)
881833e3 MD	98	* @ctx: reservation context
	99	*
	100	* Returns the event header size (including padding).
	101	*
881833e3 MD	102	* The payload must itself determine its own alignment from the biggest type it
	103	* contains.
	104	*/
	105	static __inline__
	106	unsigned char record_header_size(const struct lib_ring_buffer_config *config,
	107	struct channel *chan, size_t offset,
64c796d8	108	size_t *pre_header_padding,
881833e3 MD	109	struct lib_ring_buffer_ctx *ctx)
881833e3 MD	110	{
9115fbdc	111	struct ltt_channel *ltt_chan = channel_get_private(chan);
f1676205	112	struct ltt_event *event = ctx->priv;
881833e3 MD	113	size_t orig_offset = offset;
	114	size_t padding;
	115
9115fbdc MD	116	switch (ltt_chan->header_type) {
	117	case 1: /* compact */
	118	padding = lib_ring_buffer_align(offset, ltt_alignof(uint32_t));
	119	offset += padding;
64c796d8	120	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
9115fbdc MD	121	offset += sizeof(uint32_t); /* id and timestamp */
	122	} else {
	123	/* Minimum space taken by 5-bit id */
	124	offset += sizeof(uint8_t);
	125	/* Align extended struct on largest member */
	126	offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
	127	offset += sizeof(uint32_t); /* id */
	128	offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
	129	offset += sizeof(uint64_t); /* timestamp */
	130	}
	131	break;
	132	case 2: /* large */
	133	padding = lib_ring_buffer_align(offset, ltt_alignof(uint16_t));
	134	offset += padding;
	135	offset += sizeof(uint16_t);
64c796d8	136	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
9115fbdc MD	137	offset += lib_ring_buffer_align(offset, ltt_alignof(uint32_t));
	138	offset += sizeof(uint32_t); /* timestamp */
	139	} else {
	140	/* Align extended struct on largest member */
	141	offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
	142	offset += sizeof(uint32_t); /* id */
	143	offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
	144	offset += sizeof(uint64_t); /* timestamp */
881833e3	145	}
9115fbdc MD	146	break;
9115fbdc MD	147	default:
1b2e041f	148	padding = 0;
64c796d8	149	WARN_ON_ONCE(1);
881833e3	150	}
f1676205 MD	151	offset += ctx_get_size(offset, event->ctx);
f1676205 MD	152	offset += ctx_get_size(offset, ltt_chan->ctx);
881833e3 MD	153
	154	*pre_header_padding = padding;
	155	return offset - orig_offset;
	156	}
	157
	158	#include "wrapper/ringbuffer/api.h"
	159
eb9a7857	160	static
881833e3 MD	161	void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
881833e3 MD	162	struct lib_ring_buffer_ctx *ctx,
64c796d8	163	uint32_t event_id);
881833e3 MD	164
	165	/*
	166	* ltt_write_event_header
	167	*
	168	* Writes the event header to the offset (already aligned on 32-bits).
	169	*
	170	* @config: ring buffer instance configuration
	171	* @ctx: reservation context
4e1f08f4	172	* @event_id: event ID
881833e3 MD	173	*/
	174	static __inline__
	175	void ltt_write_event_header(const struct lib_ring_buffer_config *config,
	176	struct lib_ring_buffer_ctx *ctx,
64c796d8	177	uint32_t event_id)
881833e3	178	{
9115fbdc	179	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
f1676205	180	struct ltt_event *event = ctx->priv;
881833e3 MD	181
	182	if (unlikely(ctx->rflags))
	183	goto slow_path;
	184
9115fbdc MD	185	switch (ltt_chan->header_type) {
	186	case 1: /* compact */
	187	{
	188	uint32_t id_time = 0;
	189
4e1f08f4	190	bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
9115fbdc MD	191	bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
	192	lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
	193	break;
	194	}
	195	case 2: /* large */
	196	{
9115fbdc	197	uint32_t timestamp = (uint32_t) ctx->tsc;
7e855749	198	uint16_t id = event_id;
9115fbdc	199
7e855749	200	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
9115fbdc MD	201	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t));
	202	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	203	break;
	204	}
	205	default:
64c796d8	206	WARN_ON_ONCE(1);
9115fbdc	207	}
f1676205	208
f1676205	209	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
da4e2332	210	ctx_record(ctx, ltt_chan, event->ctx);
c595c36f	211	lib_ring_buffer_align_ctx(ctx, ctx->largest_align);
f1676205	212
9115fbdc	213	return;
881833e3 MD	214
881833e3 MD	215	slow_path:
4e1f08f4	216	ltt_write_event_header_slow(config, ctx, event_id);
881833e3 MD	217	}
881833e3 MD	218
eb9a7857	219	static
881833e3	220	void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
64c796d8 MD	221	struct lib_ring_buffer_ctx *ctx,
64c796d8 MD	222	uint32_t event_id)
881833e3	223	{
9115fbdc	224	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
f1676205	225	struct ltt_event *event = ctx->priv;
9115fbdc MD	226
	227	switch (ltt_chan->header_type) {
	228	case 1: /* compact */
64c796d8	229	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
9115fbdc MD	230	uint32_t id_time = 0;
9115fbdc MD	231
4e1f08f4	232	bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
9115fbdc MD	233	bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
	234	lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
	235	} else {
	236	uint8_t id = 0;
9115fbdc MD	237	uint64_t timestamp = ctx->tsc;
	238
	239	bt_bitfield_write(&id, uint8_t, 0, 5, 31);
	240	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
	241	/* Align extended struct on largest member */
	242	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
	243	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
	244	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
	245	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	246	}
881833e3	247	break;
9115fbdc MD	248	case 2: /* large */
9115fbdc MD	249	{
64c796d8	250	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
9115fbdc	251	uint32_t timestamp = (uint32_t) ctx->tsc;
7e855749	252	uint16_t id = event_id;
9115fbdc	253
7e855749	254	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
9115fbdc MD	255	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t));
	256	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	257	} else {
64c796d8	258	uint16_t id = 65535;
9115fbdc MD	259	uint64_t timestamp = ctx->tsc;
9115fbdc MD	260
64c796d8	261	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
9115fbdc MD	262	/* Align extended struct on largest member */
9115fbdc MD	263	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
64c796d8	264	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
9115fbdc MD	265	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
	266	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	267	}
881833e3	268	break;
881833e3	269	}
9115fbdc	270	default:
64c796d8	271	WARN_ON_ONCE(1);
881833e3	272	}
f1676205	273	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
da4e2332	274	ctx_record(ctx, ltt_chan, event->ctx);
c595c36f	275	lib_ring_buffer_align_ctx(ctx, ctx->largest_align);
881833e3 MD	276	}
881833e3 MD	277
7514523f MD	278	static const struct lib_ring_buffer_config client_config;
	279
	280	static u64 client_ring_buffer_clock_read(struct channel *chan)
	281	{
	282	return lib_ring_buffer_clock_read(chan);
	283	}
	284
1e2015dc	285	static
7514523f MD	286	size_t client_record_header_size(const struct lib_ring_buffer_config *config,
7514523f MD	287	struct channel *chan, size_t offset,
7514523f	288	size_t *pre_header_padding,
7514523f MD	289	struct lib_ring_buffer_ctx *ctx)
7514523f MD	290	{
64c796d8 MD	291	return record_header_size(config, chan, offset,
64c796d8 MD	292	pre_header_padding, ctx);
7514523f MD	293	}
	294
	295	/**
1c25284c	296	* client_packet_header_size - called on buffer-switch to a new sub-buffer
7514523f MD	297	*
	298	* Return header size without padding after the structure. Don't use packed
	299	* structure because gcc generates inefficient code on some architectures
	300	* (powerpc, mips..)
	301	*/
1c25284c	302	static size_t client_packet_header_size(void)
7514523f	303	{
9115fbdc	304	return offsetof(struct packet_header, ctx.header_end);
7514523f MD	305	}
	306
	307	static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
	308	unsigned int subbuf_idx)
	309	{
	310	struct channel *chan = buf->backend.chan;
1c25284c MD	311	struct packet_header *header =
1c25284c MD	312	(struct packet_header *)
7514523f MD	313	lib_ring_buffer_offset_address(&buf->backend,
7514523f MD	314	subbuf_idx * chan->backend.subbuf_size);
9115fbdc MD	315	struct ltt_channel *ltt_chan = channel_get_private(chan);
9115fbdc MD	316	struct ltt_session *session = ltt_chan->session;
7514523f	317
d793d5e1	318	header->magic = CTF_MAGIC_NUMBER;
1ec3f75a	319	memcpy(header->uuid, session->uuid.b, sizeof(session->uuid));
9115fbdc MD	320	header->stream_id = ltt_chan->id;
	321	header->ctx.timestamp_begin = tsc;
	322	header->ctx.timestamp_end = 0;
	323	header->ctx.events_discarded = 0;
	324	header->ctx.content_size = 0xFFFFFFFF; /* for debugging */
	325	header->ctx.packet_size = 0xFFFFFFFF;
	326	header->ctx.cpu_id = buf->backend.cpu;
7514523f MD	327	}
	328
	329	/*
	330	* offset is assumed to never be 0 here : never deliver a completely empty
	331	* subbuffer. data_size is between 1 and subbuf_size.
	332	*/
	333	static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
	334	unsigned int subbuf_idx, unsigned long data_size)
	335	{
	336	struct channel *chan = buf->backend.chan;
1c25284c MD	337	struct packet_header *header =
1c25284c MD	338	(struct packet_header *)
7514523f MD	339	lib_ring_buffer_offset_address(&buf->backend,
	340	subbuf_idx * chan->backend.subbuf_size);
	341	unsigned long records_lost = 0;
	342
9115fbdc	343	header->ctx.timestamp_end = tsc;
05d32c64 MD	344	header->ctx.content_size = data_size * CHAR_BIT; /* in bits */
05d32c64 MD	345	header->ctx.packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
7514523f MD	346	records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
	347	records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
	348	records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
9115fbdc	349	header->ctx.events_discarded = records_lost;
7514523f MD	350	}
	351
	352	static int client_buffer_create(struct lib_ring_buffer buf, void priv,
	353	int cpu, const char *name)
	354	{
1c25284c	355	return 0;
7514523f MD	356	}
	357
	358	static void client_buffer_finalize(struct lib_ring_buffer buf, void priv, int cpu)
	359	{
7514523f MD	360	}
	361
	362	static const struct lib_ring_buffer_config client_config = {
	363	.cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
	364	.cb.record_header_size = client_record_header_size,
1c25284c	365	.cb.subbuffer_header_size = client_packet_header_size,
7514523f MD	366	.cb.buffer_begin = client_buffer_begin,
	367	.cb.buffer_end = client_buffer_end,
	368	.cb.buffer_create = client_buffer_create,
	369	.cb.buffer_finalize = client_buffer_finalize,
	370
	371	.tsc_bits = 32,
	372	.alloc = RING_BUFFER_ALLOC_PER_CPU,
	373	.sync = RING_BUFFER_SYNC_PER_CPU,
3d084699	374	.mode = RING_BUFFER_MODE_TEMPLATE,
7514523f	375	.backend = RING_BUFFER_PAGE,
2db1399a	376	.output = RING_BUFFER_OUTPUT_TEMPLATE,
7514523f MD	377	.oops = RING_BUFFER_OOPS_CONSISTENCY,
	378	.ipi = RING_BUFFER_IPI_BARRIER,
	379	.wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
	380	};
	381
1e2015dc	382	static
1c25284c	383	struct channel _channel_create(const char name,
9115fbdc	384	struct ltt_channel ltt_chan, void buf_addr,
1c25284c MD	385	size_t subbuf_size, size_t num_subbuf,
	386	unsigned int switch_timer_interval,
	387	unsigned int read_timer_interval)
7514523f	388	{
9115fbdc	389	return channel_create(&client_config, name, ltt_chan, buf_addr,
7514523f MD	390	subbuf_size, num_subbuf, switch_timer_interval,
7514523f MD	391	read_timer_interval);
7514523f MD	392	}
7514523f MD	393
1e2015dc	394	static
7514523f MD	395	void ltt_channel_destroy(struct channel *chan)
7514523f MD	396	{
7514523f	397	channel_destroy(chan);
7514523f MD	398	}
7514523f MD	399
ad1c05e1 MD	400	static
	401	struct lib_ring_buffer ltt_buffer_read_open(struct channel chan)
	402	{
	403	struct lib_ring_buffer *buf;
	404	int cpu;
	405
1c25284c MD	406	for_each_channel_cpu(cpu, chan) {
1c25284c MD	407	buf = channel_get_ring_buffer(&client_config, chan, cpu);
ad1c05e1 MD	408	if (!lib_ring_buffer_open_read(buf))
	409	return buf;
	410	}
	411	return NULL;
	412	}
	413
f71ecafa MD	414	static
	415	int ltt_buffer_has_read_closed_stream(struct channel *chan)
	416	{
	417	struct lib_ring_buffer *buf;
	418	int cpu;
	419
	420	for_each_channel_cpu(cpu, chan) {
	421	buf = channel_get_ring_buffer(&client_config, chan, cpu);
	422	if (!atomic_long_read(&buf->active_readers))
	423	return 1;
	424	}
	425	return 0;
	426	}
	427
ad1c05e1	428	static
1c25284c	429	void ltt_buffer_read_close(struct lib_ring_buffer *buf)
ad1c05e1 MD	430	{
ad1c05e1 MD	431	lib_ring_buffer_release_read(buf);
1c25284c MD	432	}
1c25284c MD	433
c099397a	434	static
4e1f08f4	435	int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx,
64c796d8	436	uint32_t event_id)
1c25284c	437	{
64c796d8	438	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
1c25284c MD	439	int ret, cpu;
	440
	441	cpu = lib_ring_buffer_get_cpu(&client_config);
	442	if (cpu < 0)
	443	return -EPERM;
	444	ctx->cpu = cpu;
	445
64c796d8 MD	446	switch (ltt_chan->header_type) {
	447	case 1: /* compact */
	448	if (event_id > 30)
	449	ctx->rflags \|= LTT_RFLAG_EXTENDED;
	450	break;
	451	case 2: /* large */
	452	if (event_id > 65534)
	453	ctx->rflags \|= LTT_RFLAG_EXTENDED;
	454	break;
	455	default:
	456	WARN_ON_ONCE(1);
	457	}
	458
1c25284c MD	459	ret = lib_ring_buffer_reserve(&client_config, ctx);
	460	if (ret)
	461	goto put;
4e1f08f4 MD	462	ltt_write_event_header(&client_config, ctx, event_id);
4e1f08f4 MD	463	return 0;
1c25284c MD	464	put:
	465	lib_ring_buffer_put_cpu(&client_config);
	466	return ret;
ad1c05e1 MD	467	}
ad1c05e1 MD	468
c099397a	469	static
1c25284c MD	470	void ltt_event_commit(struct lib_ring_buffer_ctx *ctx)
	471	{
	472	lib_ring_buffer_commit(&client_config, ctx);
	473	lib_ring_buffer_put_cpu(&client_config);
	474	}
	475
c099397a	476	static
e763dbf5 MD	477	void ltt_event_write(struct lib_ring_buffer_ctx ctx, const void src,
	478	size_t len)
	479	{
	480	lib_ring_buffer_write(&client_config, ctx, src, len);
	481	}
1c25284c	482
c099397a	483	static
71c1d843	484	wait_queue_head_t ltt_get_writer_buf_wait_queue(struct channel chan, int cpu)
c099397a	485	{
71c1d843 MD	486	struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config,
	487	chan, cpu);
	488	return &buf->write_wait;
24cedcfe MD	489	}
	490
	491	static
	492	wait_queue_head_t ltt_get_hp_wait_queue(struct channel chan)
	493	{
	494	return &chan->hp_wait;
	495	}
	496
	497	static
	498	int ltt_is_finalized(struct channel *chan)
	499	{
	500	return lib_ring_buffer_channel_is_finalized(chan);
c099397a MD	501	}
c099397a MD	502
254ec7bc MD	503	static
	504	int ltt_is_disabled(struct channel *chan)
	505	{
	506	return lib_ring_buffer_channel_is_disabled(chan);
	507	}
	508
7514523f	509	static struct ltt_transport ltt_relay_transport = {
3d084699	510	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
7514523f MD	511	.owner = THIS_MODULE,
7514523f MD	512	.ops = {
1c25284c MD	513	.channel_create = _channel_create,
1c25284c MD	514	.channel_destroy = ltt_channel_destroy,
ad1c05e1	515	.buffer_read_open = ltt_buffer_read_open,
f71ecafa MD	516	.buffer_has_read_closed_stream =
f71ecafa MD	517	ltt_buffer_has_read_closed_stream,
ad1c05e1	518	.buffer_read_close = ltt_buffer_read_close,
1c25284c MD	519	.event_reserve = ltt_event_reserve,
1c25284c MD	520	.event_commit = ltt_event_commit,
e763dbf5	521	.event_write = ltt_event_write,
1ec3f75a	522	.packet_avail_size = NULL, /* Would be racy anyway */
71c1d843	523	.get_writer_buf_wait_queue = ltt_get_writer_buf_wait_queue,
24cedcfe MD	524	.get_hp_wait_queue = ltt_get_hp_wait_queue,
24cedcfe MD	525	.is_finalized = ltt_is_finalized,
254ec7bc	526	.is_disabled = ltt_is_disabled,
7514523f MD	527	},
	528	};
	529
3d084699	530	static int __init ltt_ring_buffer_client_init(void)
7514523f	531	{
a509e133 MD	532	/*
	533	* This vmalloc sync all also takes care of the lib ring buffer
	534	* vmalloc'd module pages when it is built as a module into LTTng.
	535	*/
6d2a620c	536	wrapper_vmalloc_sync_all();
7514523f MD	537	ltt_transport_register(&ltt_relay_transport);
	538	return 0;
	539	}
	540
1c25284c MD	541	module_init(ltt_ring_buffer_client_init);
1c25284c MD	542
3d084699	543	static void __exit ltt_ring_buffer_client_exit(void)
7514523f	544	{
7514523f MD	545	ltt_transport_unregister(&ltt_relay_transport);
	546	}
	547
1c25284c MD	548	module_exit(ltt_ring_buffer_client_exit);
1c25284c MD	549
7514523f MD	550	MODULE_LICENSE("GPL and additional rights");
7514523f MD	551	MODULE_AUTHOR("Mathieu Desnoyers");
3d084699 MD	552	MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
3d084699 MD	553	" client");