[lttng-ust.git] / libust / 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 <stdint.h>
#include <ust/lttng-events.h>
#include "ust/bitfield.h"
#include "ust/clock.h"
#include "ltt-tracer.h"
#include "../libringbuffer/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.
 */

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, lttng_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, lttng_alignof(uint64_t));
			offset += sizeof(uint32_t);	/* id */
			offset += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
			offset += sizeof(uint64_t);	/* timestamp */
		}
		break;
	case 2:	/* large */
		padding = lib_ring_buffer_align(offset, lttng_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, lttng_alignof(uint32_t));
			offset += sizeof(uint32_t);	/* timestamp */
		} else {
			/* Align extended struct on largest member */
			offset += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
			offset += sizeof(uint32_t);	/* id */
			offset += lib_ring_buffer_align(offset, lttng_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 "../libringbuffer/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, lttng_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);

	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, lttng_alignof(uint64_t));
			lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
			lib_ring_buffer_align_ctx(ctx, lttng_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, lttng_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, lttng_alignof(uint64_t));
			lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
			lib_ring_buffer_align_ctx(ctx, lttng_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);
}

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 shm_handle *handle)
{
	struct channel *chan = shmp(handle, buf->backend.chan);
	struct packet_header *header =
		(struct packet_header *)
			lib_ring_buffer_offset_address(&buf->backend,
				subbuf_idx * chan->backend.subbuf_size,
				handle);
	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, 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 shm_handle *handle)
{
	struct channel *chan = shmp(handle, buf->backend.chan);
	struct packet_header *header =
		(struct packet_header *)
			lib_ring_buffer_offset_address(&buf->backend,
				subbuf_idx * chan->backend.subbuf_size,
				handle);
	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 */
	/*
	 * 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);
	header->ctx.events_discarded = records_lost;
}

static int client_buffer_create(struct lib_ring_buffer *buf, void *priv,
				int cpu, const char *name, struct shm_handle *handle)
{
	return 0;
}

static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu, struct shm_handle *handle)
{
}

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_GLOBAL,
	.mode = RING_BUFFER_MODE_TEMPLATE,
	.backend = RING_BUFFER_PAGE,
	.output = RING_BUFFER_MMAP,
	.oops = RING_BUFFER_OOPS_CONSISTENCY,
	.ipi = RING_BUFFER_NO_IPI_BARRIER,
	.wakeup = RING_BUFFER_WAKEUP_BY_WRITER,
};

static
struct ltt_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)
{
	ltt_chan->handle = channel_create(&client_config, name, ltt_chan, buf_addr,
			      subbuf_size, num_subbuf, switch_timer_interval,
			      read_timer_interval);
	if (!ltt_chan->handle)
		return NULL;
	ltt_chan->chan = shmp(ltt_chan->handle, ltt_chan->handle->chan);
	return ltt_chan;
}

static
void ltt_channel_destroy(struct ltt_channel *ltt_chan)
{
	channel_destroy(ltt_chan->chan, ltt_chan->handle);
}

static
struct lib_ring_buffer *ltt_buffer_read_open(struct channel *chan,
					     struct shm_handle *handle,
					     int *shm_fd, int *wait_fd,
					     uint64_t *memory_map_size)
{
	struct lib_ring_buffer *buf;
	int cpu;

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

static
void ltt_buffer_read_close(struct lib_ring_buffer *buf,
			   struct shm_handle *handle)
{
	lib_ring_buffer_release_read(buf, handle);
}

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);
}

#if 0
static
wait_queue_head_t *ltt_get_reader_wait_queue(struct channel *chan)
{
	return &chan->read_wait;
}

static
wait_queue_head_t *ltt_get_hp_wait_queue(struct channel *chan)
{
	return &chan->hp_wait;
}
#endif //0

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 "-mmap",
	.ops = {
		.channel_create = _channel_create,
		.channel_destroy = ltt_channel_destroy,
		.buffer_read_open = ltt_buffer_read_open,
		.buffer_read_close = ltt_buffer_read_close,
		.event_reserve = ltt_event_reserve,
		.event_commit = ltt_event_commit,
		.event_write = ltt_event_write,
		.packet_avail_size = NULL,	/* Would be racy anyway */
		//.get_reader_wait_queue = ltt_get_reader_wait_queue,
		//.get_hp_wait_queue = ltt_get_hp_wait_queue,
		.is_finalized = ltt_is_finalized,
		.is_disabled = ltt_is_disabled,
	},
};

void RING_BUFFER_MODE_TEMPLATE_INIT(void)
{
	DBG("LTT : ltt ring buffer client init\n");
	ltt_transport_register(&ltt_relay_transport);
}

void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
{
	DBG("LTT : ltt ring buffer client exit\n");
	ltt_transport_unregister(&ltt_relay_transport);
}
Commit	Line	Data
3d1fc7fd MD	1	/*
	2	* ltt-ring-buffer-client.h
	3	*
	4	* Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	5	*
	6	* LTTng lib ring buffer client template.
	7	*
	8	* Dual LGPL v2.1/GPL v2 license.
	9	*/
	10
9f3fdbc6	11	#include <stdint.h>
1ea172a1	12	#include <ust/lttng-events.h>
9f3fdbc6 MD	13	#include "ust/bitfield.h"
9f3fdbc6 MD	14	#include "ust/clock.h"
3d1fc7fd	15	#include "ltt-tracer.h"
9f3fdbc6	16	#include "../libringbuffer/frontend_types.h"
3d1fc7fd MD	17
	18	/*
	19	* Keep the natural field alignment for _each field_ within this structure if
	20	* you ever add/remove a field from this header. Packed attribute is not used
	21	* because gcc generates poor code on at least powerpc and mips. Don't ever
	22	* let gcc add padding between the structure elements.
	23	*/
	24
	25	struct packet_header {
	26	/* Trace packet header */
	27	uint32_t magic; /*
	28	* Trace magic number.
	29	* contains endianness information.
	30	*/
	31	uint8_t uuid[16];
	32	uint32_t stream_id;
	33
	34	struct {
	35	/* Stream packet context */
	36	uint64_t timestamp_begin; /* Cycle count at subbuffer start */
	37	uint64_t timestamp_end; /* Cycle count at subbuffer end */
	38	uint32_t events_discarded; /*
	39	* Events lost in this subbuffer since
	40	* the beginning of the trace.
	41	* (may overflow)
	42	*/
	43	uint32_t content_size; /* Size of data in subbuffer */
	44	uint32_t packet_size; /* Subbuffer size (include padding) */
	45	uint32_t cpu_id; /* CPU id associated with stream */
	46	uint8_t header_end; /* End of header */
	47	} ctx;
	48	};
	49
	50
	51	static inline notrace u64 lib_ring_buffer_clock_read(struct channel *chan)
	52	{
	53	return trace_clock_read64();
	54	}
	55
	56	static inline
	57	size_t ctx_get_size(size_t offset, struct lttng_ctx *ctx)
	58	{
	59	int i;
	60	size_t orig_offset = offset;
	61
	62	if (likely(!ctx))
	63	return 0;
	64	for (i = 0; i < ctx->nr_fields; i++)
	65	offset += ctx->fields[i].get_size(offset);
	66	return offset - orig_offset;
	67	}
	68
	69	static inline
	70	void ctx_record(struct lib_ring_buffer_ctx *bufctx,
	71	struct ltt_channel *chan,
	72	struct lttng_ctx *ctx)
	73	{
	74	int i;
	75
	76	if (likely(!ctx))
	77	return;
	78	for (i = 0; i < ctx->nr_fields; i++)
	79	ctx->fields[i].record(&ctx->fields[i], bufctx, chan);
	80	}
81
82	/*
83	* record_header_size - Calculate the header size and padding necessary.
84	* @config: ring buffer instance configuration
85	* @chan: channel
86	* @offset: offset in the write buffer
87	* @pre_header_padding: padding to add before the header (output)
88	* @ctx: reservation context
89	*
90	* Returns the event header size (including padding).
91	*
92	* The payload must itself determine its own alignment from the biggest type it
93	* contains.
94	*/
95	static __inline__
96	unsigned char record_header_size(const struct lib_ring_buffer_config *config,
97	struct channel *chan, size_t offset,
98	size_t *pre_header_padding,
99	struct lib_ring_buffer_ctx *ctx)
100	{
101	struct ltt_channel *ltt_chan = channel_get_private(chan);
102	struct ltt_event *event = ctx->priv;
103	size_t orig_offset = offset;
104	size_t padding;
105
106	switch (ltt_chan->header_type) {
107	case 1: /* compact */
1dbfff0c	108	padding = lib_ring_buffer_align(offset, lttng_alignof(uint32_t));
3d1fc7fd MD	109	offset += padding;
	110	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
	111	offset += sizeof(uint32_t); /* id and timestamp */
	112	} else {
	113	/* Minimum space taken by 5-bit id */
	114	offset += sizeof(uint8_t);
	115	/* Align extended struct on largest member */
1dbfff0c	116	offset += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
3d1fc7fd	117	offset += sizeof(uint32_t); /* id */
1dbfff0c	118	offset += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
3d1fc7fd MD	119	offset += sizeof(uint64_t); /* timestamp */
	120	}
	121	break;
	122	case 2: /* large */
1dbfff0c	123	padding = lib_ring_buffer_align(offset, lttng_alignof(uint16_t));
3d1fc7fd MD	124	offset += padding;
	125	offset += sizeof(uint16_t);
	126	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
1dbfff0c	127	offset += lib_ring_buffer_align(offset, lttng_alignof(uint32_t));
3d1fc7fd MD	128	offset += sizeof(uint32_t); /* timestamp */
	129	} else {
	130	/* Align extended struct on largest member */
1dbfff0c	131	offset += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
3d1fc7fd	132	offset += sizeof(uint32_t); /* id */
1dbfff0c	133	offset += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
3d1fc7fd MD	134	offset += sizeof(uint64_t); /* timestamp */
	135	}
	136	break;
	137	default:
9f3fdbc6	138	padding = 0;
3d1fc7fd MD	139	WARN_ON_ONCE(1);
	140	}
	141	offset += ctx_get_size(offset, event->ctx);
	142	offset += ctx_get_size(offset, ltt_chan->ctx);
	143
	144	*pre_header_padding = padding;
	145	return offset - orig_offset;
	146	}
	147
9f3fdbc6	148	#include "../libringbuffer/api.h"
3d1fc7fd	149
9f3fdbc6	150	static
3d1fc7fd MD	151	void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
	152	struct lib_ring_buffer_ctx *ctx,
	153	uint32_t event_id);
	154
	155	/*
	156	* ltt_write_event_header
	157	*
	158	* Writes the event header to the offset (already aligned on 32-bits).
	159	*
	160	* @config: ring buffer instance configuration
	161	* @ctx: reservation context
	162	* @event_id: event ID
	163	*/
	164	static __inline__
	165	void ltt_write_event_header(const struct lib_ring_buffer_config *config,
	166	struct lib_ring_buffer_ctx *ctx,
	167	uint32_t event_id)
	168	{
	169	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
	170	struct ltt_event *event = ctx->priv;
	171
	172	if (unlikely(ctx->rflags))
	173	goto slow_path;
	174
	175	switch (ltt_chan->header_type) {
	176	case 1: /* compact */
	177	{
	178	uint32_t id_time = 0;
	179
	180	bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
	181	bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
	182	lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
	183	break;
	184	}
	185	case 2: /* large */
	186	{
	187	uint32_t timestamp = (uint32_t) ctx->tsc;
	188	uint16_t id = event_id;
	189
	190	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
1dbfff0c	191	lib_ring_buffer_align_ctx(ctx, lttng_alignof(uint32_t));
3d1fc7fd MD	192	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	193	break;
	194	}
	195	default:
	196	WARN_ON_ONCE(1);
	197	}
	198
3d1fc7fd	199	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
1ea172a1	200	ctx_record(ctx, ltt_chan, event->ctx);
3d1fc7fd MD	201
	202	return;
	203
	204	slow_path:
	205	ltt_write_event_header_slow(config, ctx, event_id);
	206	}
	207
9f3fdbc6	208	static
3d1fc7fd MD	209	void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
	210	struct lib_ring_buffer_ctx *ctx,
	211	uint32_t event_id)
	212	{
	213	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
	214	struct ltt_event *event = ctx->priv;
	215
	216	switch (ltt_chan->header_type) {
	217	case 1: /* compact */
	218	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
	219	uint32_t id_time = 0;
	220
	221	bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
	222	bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
	223	lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
	224	} else {
	225	uint8_t id = 0;
	226	uint64_t timestamp = ctx->tsc;
	227
	228	bt_bitfield_write(&id, uint8_t, 0, 5, 31);
	229	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
	230	/* Align extended struct on largest member */
1dbfff0c	231	lib_ring_buffer_align_ctx(ctx, lttng_alignof(uint64_t));
3d1fc7fd	232	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
1dbfff0c	233	lib_ring_buffer_align_ctx(ctx, lttng_alignof(uint64_t));
3d1fc7fd MD	234	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	235	}
	236	break;
	237	case 2: /* large */
	238	{
	239	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
	240	uint32_t timestamp = (uint32_t) ctx->tsc;
	241	uint16_t id = event_id;
	242
	243	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
1dbfff0c	244	lib_ring_buffer_align_ctx(ctx, lttng_alignof(uint32_t));
3d1fc7fd MD	245	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	246	} else {
	247	uint16_t id = 65535;
	248	uint64_t timestamp = ctx->tsc;
	249
	250	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
	251	/* Align extended struct on largest member */
1dbfff0c	252	lib_ring_buffer_align_ctx(ctx, lttng_alignof(uint64_t));
3d1fc7fd	253	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
1dbfff0c	254	lib_ring_buffer_align_ctx(ctx, lttng_alignof(uint64_t));
3d1fc7fd MD	255	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	256	}
	257	break;
	258	}
	259	default:
	260	WARN_ON_ONCE(1);
	261	}
3d1fc7fd	262	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
1ea172a1	263	ctx_record(ctx, ltt_chan, event->ctx);
3d1fc7fd MD	264	}
	265
	266	static const struct lib_ring_buffer_config client_config;
	267
	268	static u64 client_ring_buffer_clock_read(struct channel *chan)
	269	{
	270	return lib_ring_buffer_clock_read(chan);
	271	}
	272
	273	static
	274	size_t client_record_header_size(const struct lib_ring_buffer_config *config,
	275	struct channel *chan, size_t offset,
	276	size_t *pre_header_padding,
	277	struct lib_ring_buffer_ctx *ctx)
	278	{
	279	return record_header_size(config, chan, offset,
	280	pre_header_padding, ctx);
	281	}
	282
	283	/**
	284	* client_packet_header_size - called on buffer-switch to a new sub-buffer
	285	*
	286	* Return header size without padding after the structure. Don't use packed
	287	* structure because gcc generates inefficient code on some architectures
	288	* (powerpc, mips..)
	289	*/
	290	static size_t client_packet_header_size(void)
	291	{
	292	return offsetof(struct packet_header, ctx.header_end);
	293	}
	294
	295	static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
1d498196 MD	296	unsigned int subbuf_idx,
1d498196 MD	297	struct shm_handle *handle)
3d1fc7fd	298	{
1d498196	299	struct channel *chan = shmp(handle, buf->backend.chan);
3d1fc7fd MD	300	struct packet_header *header =
	301	(struct packet_header *)
	302	lib_ring_buffer_offset_address(&buf->backend,
1d498196 MD	303	subbuf_idx * chan->backend.subbuf_size,
1d498196 MD	304	handle);
3d1fc7fd MD	305	struct ltt_channel *ltt_chan = channel_get_private(chan);
	306	struct ltt_session *session = ltt_chan->session;
	307
	308	header->magic = CTF_MAGIC_NUMBER;
9f3fdbc6	309	memcpy(header->uuid, session->uuid, sizeof(session->uuid));
3d1fc7fd MD	310	header->stream_id = ltt_chan->id;
	311	header->ctx.timestamp_begin = tsc;
	312	header->ctx.timestamp_end = 0;
	313	header->ctx.events_discarded = 0;
	314	header->ctx.content_size = 0xFFFFFFFF; /* for debugging */
	315	header->ctx.packet_size = 0xFFFFFFFF;
	316	header->ctx.cpu_id = buf->backend.cpu;
	317	}
	318
	319	/*
	320	* offset is assumed to never be 0 here : never deliver a completely empty
	321	* subbuffer. data_size is between 1 and subbuf_size.
	322	*/
	323	static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
1d498196 MD	324	unsigned int subbuf_idx, unsigned long data_size,
1d498196 MD	325	struct shm_handle *handle)
3d1fc7fd	326	{
1d498196	327	struct channel *chan = shmp(handle, buf->backend.chan);
3d1fc7fd MD	328	struct packet_header *header =
	329	(struct packet_header *)
	330	lib_ring_buffer_offset_address(&buf->backend,
1d498196 MD	331	subbuf_idx * chan->backend.subbuf_size,
1d498196 MD	332	handle);
3d1fc7fd MD	333	unsigned long records_lost = 0;
	334
	335	header->ctx.timestamp_end = tsc;
	336	header->ctx.content_size = data_size * CHAR_BIT; /* in bits */
	337	header->ctx.packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
9dcb02ef MD	338	/*
	339	* We do not care about the records lost count, because the metadata
	340	* channel waits and retry.
	341	*/
	342	(void) lib_ring_buffer_get_records_lost_full(&client_config, buf);
3d1fc7fd MD	343	records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
	344	records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
	345	header->ctx.events_discarded = records_lost;
	346	}
	347
	348	static int client_buffer_create(struct lib_ring_buffer buf, void priv,
1d498196	349	int cpu, const char name, struct shm_handle handle)
3d1fc7fd MD	350	{
	351	return 0;
	352	}
	353
1d498196	354	static void client_buffer_finalize(struct lib_ring_buffer buf, void priv, int cpu, struct shm_handle *handle)
3d1fc7fd MD	355	{
	356	}
	357
	358	static const struct lib_ring_buffer_config client_config = {
	359	.cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
	360	.cb.record_header_size = client_record_header_size,
	361	.cb.subbuffer_header_size = client_packet_header_size,
	362	.cb.buffer_begin = client_buffer_begin,
	363	.cb.buffer_end = client_buffer_end,
	364	.cb.buffer_create = client_buffer_create,
	365	.cb.buffer_finalize = client_buffer_finalize,
	366
	367	.tsc_bits = 32,
	368	.alloc = RING_BUFFER_ALLOC_PER_CPU,
5d61a504	369	.sync = RING_BUFFER_SYNC_GLOBAL,
3d1fc7fd MD	370	.mode = RING_BUFFER_MODE_TEMPLATE,
3d1fc7fd MD	371	.backend = RING_BUFFER_PAGE,
5d61a504	372	.output = RING_BUFFER_MMAP,
3d1fc7fd	373	.oops = RING_BUFFER_OOPS_CONSISTENCY,
5d61a504 MD	374	.ipi = RING_BUFFER_NO_IPI_BARRIER,
5d61a504 MD	375	.wakeup = RING_BUFFER_WAKEUP_BY_WRITER,
3d1fc7fd MD	376	};
	377
	378	static
1d498196	379	struct ltt_channel _channel_create(const char name,
3d1fc7fd MD	380	struct ltt_channel ltt_chan, void buf_addr,
	381	size_t subbuf_size, size_t num_subbuf,
	382	unsigned int switch_timer_interval,
8d8a24c8	383	unsigned int read_timer_interval)
3d1fc7fd	384	{
1d498196	385	ltt_chan->handle = channel_create(&client_config, name, ltt_chan, buf_addr,
3d1fc7fd	386	subbuf_size, num_subbuf, switch_timer_interval,
8d8a24c8	387	read_timer_interval);
afdf9825 MD	388	if (!ltt_chan->handle)
afdf9825 MD	389	return NULL;
dc613eb9	390	ltt_chan->chan = shmp(ltt_chan->handle, ltt_chan->handle->chan);
1d498196	391	return ltt_chan;
3d1fc7fd MD	392	}
	393
	394	static
1d498196	395	void ltt_channel_destroy(struct ltt_channel *ltt_chan)
3d1fc7fd	396	{
1d498196	397	channel_destroy(ltt_chan->chan, ltt_chan->handle);
3d1fc7fd MD	398	}
	399
	400	static
1d498196	401	struct lib_ring_buffer ltt_buffer_read_open(struct channel chan,
381c0f1e MD	402	struct shm_handle *handle,
	403	int shm_fd, int wait_fd,
	404	uint64_t *memory_map_size)
3d1fc7fd MD	405	{
	406	struct lib_ring_buffer *buf;
	407	int cpu;
	408
	409	for_each_channel_cpu(cpu, chan) {
381c0f1e MD	410	buf = channel_get_ring_buffer(&client_config, chan,
	411	cpu, handle, shm_fd, wait_fd,
	412	memory_map_size);
1d498196	413	if (!lib_ring_buffer_open_read(buf, handle))
3d1fc7fd MD	414	return buf;
	415	}
	416	return NULL;
	417	}
	418
	419	static
1d498196 MD	420	void ltt_buffer_read_close(struct lib_ring_buffer *buf,
1d498196 MD	421	struct shm_handle *handle)
3d1fc7fd	422	{
1d498196	423	lib_ring_buffer_release_read(buf, handle);
3d1fc7fd MD	424	}
	425
	426	static
	427	int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx,
	428	uint32_t event_id)
	429	{
	430	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
	431	int ret, cpu;
	432
	433	cpu = lib_ring_buffer_get_cpu(&client_config);
	434	if (cpu < 0)
	435	return -EPERM;
	436	ctx->cpu = cpu;
	437
	438	switch (ltt_chan->header_type) {
	439	case 1: /* compact */
	440	if (event_id > 30)
	441	ctx->rflags \|= LTT_RFLAG_EXTENDED;
	442	break;
	443	case 2: /* large */
	444	if (event_id > 65534)
	445	ctx->rflags \|= LTT_RFLAG_EXTENDED;
	446	break;
	447	default:
	448	WARN_ON_ONCE(1);
	449	}
	450
	451	ret = lib_ring_buffer_reserve(&client_config, ctx);
	452	if (ret)
	453	goto put;
	454	ltt_write_event_header(&client_config, ctx, event_id);
	455	return 0;
	456	put:
	457	lib_ring_buffer_put_cpu(&client_config);
	458	return ret;
	459	}
	460
	461	static
	462	void ltt_event_commit(struct lib_ring_buffer_ctx *ctx)
	463	{
	464	lib_ring_buffer_commit(&client_config, ctx);
	465	lib_ring_buffer_put_cpu(&client_config);
	466	}
	467
	468	static
	469	void ltt_event_write(struct lib_ring_buffer_ctx ctx, const void src,
	470	size_t len)
	471	{
	472	lib_ring_buffer_write(&client_config, ctx, src, len);
	473	}
	474
9f3fdbc6	475	#if 0
3d1fc7fd MD	476	static
	477	wait_queue_head_t ltt_get_reader_wait_queue(struct channel chan)
	478	{
	479	return &chan->read_wait;
	480	}
	481
	482	static
	483	wait_queue_head_t ltt_get_hp_wait_queue(struct channel chan)
	484	{
	485	return &chan->hp_wait;
	486	}
9f3fdbc6	487	#endif //0
3d1fc7fd MD	488
	489	static
	490	int ltt_is_finalized(struct channel *chan)
	491	{
	492	return lib_ring_buffer_channel_is_finalized(chan);
	493	}
	494
	495	static
	496	int ltt_is_disabled(struct channel *chan)
	497	{
	498	return lib_ring_buffer_channel_is_disabled(chan);
	499	}
	500
	501	static struct ltt_transport ltt_relay_transport = {
818173b9	502	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap",
3d1fc7fd MD	503	.ops = {
	504	.channel_create = _channel_create,
	505	.channel_destroy = ltt_channel_destroy,
	506	.buffer_read_open = ltt_buffer_read_open,
	507	.buffer_read_close = ltt_buffer_read_close,
	508	.event_reserve = ltt_event_reserve,
	509	.event_commit = ltt_event_commit,
	510	.event_write = ltt_event_write,
	511	.packet_avail_size = NULL, /* Would be racy anyway */
9f3fdbc6 MD	512	//.get_reader_wait_queue = ltt_get_reader_wait_queue,
9f3fdbc6 MD	513	//.get_hp_wait_queue = ltt_get_hp_wait_queue,
3d1fc7fd MD	514	.is_finalized = ltt_is_finalized,
	515	.is_disabled = ltt_is_disabled,
	516	},
	517	};
	518
edaa1431	519	void RING_BUFFER_MODE_TEMPLATE_INIT(void)
3d1fc7fd	520	{
18c1cd87	521	DBG("LTT : ltt ring buffer client init\n");
3d1fc7fd	522	ltt_transport_register(&ltt_relay_transport);
3d1fc7fd MD	523	}
3d1fc7fd MD	524
edaa1431	525	void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
3d1fc7fd	526	{
18c1cd87	527	DBG("LTT : ltt ring buffer client exit\n");
3d1fc7fd MD	528	ltt_transport_unregister(&ltt_relay_transport);
3d1fc7fd MD	529	}