[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 <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.
 */

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:
		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"

extern
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, event->ctx);
	ctx_record(ctx, ltt_chan, ltt_chan->ctx);

	return;

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

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, event->ctx);
	ctx_record(ctx, ltt_chan, ltt_chan->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 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_SPLICE,
	.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
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_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;
}

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_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,
	},
};

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();
	printk(KERN_INFO "LTT : ltt ring buffer client init\n");
	ltt_transport_register(&ltt_relay_transport);
	return 0;
}

module_init(ltt_ring_buffer_client_init);

static void __exit ltt_ring_buffer_client_exit(void)
{
	printk(KERN_INFO "LTT : ltt ring buffer client exit\n");
	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
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
	11	#include <linux/module.h>
	12	#include <linux/types.h>
	13	#include "lib/bitfield.h"
	14	#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
	15	#include "wrapper/trace-clock.h"
	16	#include "ltt-events.h"
	17	#include "ltt-tracer.h"
	18	#include "wrapper/ringbuffer/frontend_types.h"
	19
	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.
	25	*/
	26
	27	struct packet_header {
	28	/* Trace packet header */
	29	uint32_t magic; /*
	30	* Trace magic number.
	31	* contains endianness information.
	32	*/
	33	uint8_t uuid[16];
	34	uint32_t stream_id;
	35
	36	struct {
	37	/* Stream packet context */
	38	uint64_t timestamp_begin; /* Cycle count at subbuffer start */
	39	uint64_t timestamp_end; /* Cycle count at subbuffer end */
	40	uint32_t events_discarded; /*
	41	* Events lost in this subbuffer since
	42	* the beginning of the trace.
	43	* (may overflow)
	44	*/
	45	uint32_t content_size; /* Size of data in subbuffer */
	46	uint32_t packet_size; /* Subbuffer size (include padding) */
	47	uint32_t cpu_id; /* CPU id associated with stream */
	48	uint8_t header_end; /* End of header */
	49	} ctx;
	50	};
	51
	52
	53	static inline notrace u64 lib_ring_buffer_clock_read(struct channel *chan)
	54	{
	55	return trace_clock_read64();
	56	}
	57
	58	static inline
	59	size_t ctx_get_size(size_t offset, struct lttng_ctx *ctx)
	60	{
	61	int i;
	62	size_t orig_offset = offset;
	63
	64	if (likely(!ctx))
65	return 0;
66	for (i = 0; i < ctx->nr_fields; i++)
67	offset += ctx->fields[i].get_size(offset);
68	return offset - orig_offset;
69	}
70
71	static inline
72	void ctx_record(struct lib_ring_buffer_ctx *bufctx,
73	struct ltt_channel *chan,
74	struct lttng_ctx *ctx)
75	{
76	int i;
77
78	if (likely(!ctx))
79	return;
80	for (i = 0; i < ctx->nr_fields; i++)
81	ctx->fields[i].record(&ctx->fields[i], bufctx, chan);
82	}
83
84	/*
85	* record_header_size - Calculate the header size and padding necessary.
86	* @config: ring buffer instance configuration
87	* @chan: channel
88	* @offset: offset in the write buffer
89	* @pre_header_padding: padding to add before the header (output)
90	* @ctx: reservation context
91	*
92	* Returns the event header size (including padding).
93	*
94	* The payload must itself determine its own alignment from the biggest type it
95	* contains.
96	*/
97	static __inline__
98	unsigned char record_header_size(const struct lib_ring_buffer_config *config,
99	struct channel *chan, size_t offset,
100	size_t *pre_header_padding,
101	struct lib_ring_buffer_ctx *ctx)
102	{
103	struct ltt_channel *ltt_chan = channel_get_private(chan);
104	struct ltt_event *event = ctx->priv;
105	size_t orig_offset = offset;
106	size_t padding;
107
108	switch (ltt_chan->header_type) {
109	case 1: /* compact */
110	padding = lib_ring_buffer_align(offset, ltt_alignof(uint32_t));
111	offset += padding;
112	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
113	offset += sizeof(uint32_t); /* id and timestamp */
114	} else {
115	/* Minimum space taken by 5-bit id */
116	offset += sizeof(uint8_t);
117	/* Align extended struct on largest member */
118	offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
119	offset += sizeof(uint32_t); /* id */
120	offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
121	offset += sizeof(uint64_t); /* timestamp */
122	}
123	break;
124	case 2: /* large */
125	padding = lib_ring_buffer_align(offset, ltt_alignof(uint16_t));
126	offset += padding;
127	offset += sizeof(uint16_t);
128	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
129	offset += lib_ring_buffer_align(offset, ltt_alignof(uint32_t));
130	offset += sizeof(uint32_t); /* timestamp */
131	} else {
132	/* Align extended struct on largest member */
133	offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
134	offset += sizeof(uint32_t); /* id */
135	offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
136	offset += sizeof(uint64_t); /* timestamp */
137	}
138	break;
139	default:
140	WARN_ON_ONCE(1);
141	}
142	offset += ctx_get_size(offset, event->ctx);
143	offset += ctx_get_size(offset, ltt_chan->ctx);
144
145	*pre_header_padding = padding;
146	return offset - orig_offset;
147	}
148
149	#include "wrapper/ringbuffer/api.h"
150
151	extern
152	void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
153	struct lib_ring_buffer_ctx *ctx,
154	uint32_t event_id);
155
156	/*
157	* ltt_write_event_header
158	*
159	* Writes the event header to the offset (already aligned on 32-bits).
160	*
161	* @config: ring buffer instance configuration
162	* @ctx: reservation context
163	* @event_id: event ID
164	*/
165	static __inline__
166	void ltt_write_event_header(const struct lib_ring_buffer_config *config,
167	struct lib_ring_buffer_ctx *ctx,
168	uint32_t event_id)
169	{
170	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
171	struct ltt_event *event = ctx->priv;
172
173	if (unlikely(ctx->rflags))
174	goto slow_path;
175
176	switch (ltt_chan->header_type) {
177	case 1: /* compact */
178	{
179	uint32_t id_time = 0;
180
181	bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
182	bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
183	lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
184	break;
185	}
186	case 2: /* large */
187	{
188	uint32_t timestamp = (uint32_t) ctx->tsc;
189	uint16_t id = event_id;
190
191	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
192	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t));
193	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
194	break;
195	}
196	default:
197	WARN_ON_ONCE(1);
198	}
199
200	ctx_record(ctx, ltt_chan, event->ctx);
201	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
202
203	return;
204
205	slow_path:
206	ltt_write_event_header_slow(config, ctx, event_id);
207	}
208
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 */
231	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
232	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
233	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
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));
244	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t));
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 */
252	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
253	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
254	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
255	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
256	}
257	break;
258	}
259	default:
260	WARN_ON_ONCE(1);
261	}
262	ctx_record(ctx, ltt_chan, event->ctx);
263	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
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,
296	unsigned int subbuf_idx)
297	{
298	struct channel *chan = buf->backend.chan;
299	struct packet_header *header =
300	(struct packet_header *)
301	lib_ring_buffer_offset_address(&buf->backend,
302	subbuf_idx * chan->backend.subbuf_size);
303	struct ltt_channel *ltt_chan = channel_get_private(chan);
304	struct ltt_session *session = ltt_chan->session;
305
306	header->magic = CTF_MAGIC_NUMBER;
307	memcpy(header->uuid, session->uuid.b, sizeof(session->uuid));
308	header->stream_id = ltt_chan->id;
309	header->ctx.timestamp_begin = tsc;
310	header->ctx.timestamp_end = 0;
311	header->ctx.events_discarded = 0;
312	header->ctx.content_size = 0xFFFFFFFF; /* for debugging */
313	header->ctx.packet_size = 0xFFFFFFFF;
314	header->ctx.cpu_id = buf->backend.cpu;
315	}
316
317	/*
318	* offset is assumed to never be 0 here : never deliver a completely empty
319	* subbuffer. data_size is between 1 and subbuf_size.
320	*/
321	static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
322	unsigned int subbuf_idx, unsigned long data_size)
323	{
324	struct channel *chan = buf->backend.chan;
325	struct packet_header *header =
326	(struct packet_header *)
327	lib_ring_buffer_offset_address(&buf->backend,
328	subbuf_idx * chan->backend.subbuf_size);
329	unsigned long records_lost = 0;
330
331	header->ctx.timestamp_end = tsc;
332	header->ctx.content_size = data_size * CHAR_BIT; /* in bits */
333	header->ctx.packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
334	records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
335	records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
336	records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
337	header->ctx.events_discarded = records_lost;
338	}
339
340	static int client_buffer_create(struct lib_ring_buffer buf, void priv,
341	int cpu, const char *name)
342	{
343	return 0;
344	}
345
346	static void client_buffer_finalize(struct lib_ring_buffer buf, void priv, int cpu)
347	{
348	}
349
350	static const struct lib_ring_buffer_config client_config = {
351	.cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
352	.cb.record_header_size = client_record_header_size,
353	.cb.subbuffer_header_size = client_packet_header_size,
354	.cb.buffer_begin = client_buffer_begin,
355	.cb.buffer_end = client_buffer_end,
356	.cb.buffer_create = client_buffer_create,
357	.cb.buffer_finalize = client_buffer_finalize,
358
359	.tsc_bits = 32,
360	.alloc = RING_BUFFER_ALLOC_PER_CPU,
361	.sync = RING_BUFFER_SYNC_PER_CPU,
362	.mode = RING_BUFFER_MODE_TEMPLATE,
363	.backend = RING_BUFFER_PAGE,
364	.output = RING_BUFFER_SPLICE,
365	.oops = RING_BUFFER_OOPS_CONSISTENCY,
366	.ipi = RING_BUFFER_IPI_BARRIER,
367	.wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
368	};
369
370	static
371	struct channel _channel_create(const char name,
372	struct ltt_channel ltt_chan, void buf_addr,
373	size_t subbuf_size, size_t num_subbuf,
374	unsigned int switch_timer_interval,
375	unsigned int read_timer_interval)
376	{
377	return channel_create(&client_config, name, ltt_chan, buf_addr,
378	subbuf_size, num_subbuf, switch_timer_interval,
379	read_timer_interval);
380	}
381
382	static
383	void ltt_channel_destroy(struct channel *chan)
384	{
385	channel_destroy(chan);
386	}
387
388	static
389	struct lib_ring_buffer ltt_buffer_read_open(struct channel chan)
390	{
391	struct lib_ring_buffer *buf;
392	int cpu;
393
394	for_each_channel_cpu(cpu, chan) {
395	buf = channel_get_ring_buffer(&client_config, chan, cpu);
396	if (!lib_ring_buffer_open_read(buf))
397	return buf;
398	}
399	return NULL;
400	}
401
402	static
403	void ltt_buffer_read_close(struct lib_ring_buffer *buf)
404	{
405	lib_ring_buffer_release_read(buf);
406	}
407
408	static
409	int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx,
410	uint32_t event_id)
411	{
412	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
413	int ret, cpu;
414
415	cpu = lib_ring_buffer_get_cpu(&client_config);
416	if (cpu < 0)
417	return -EPERM;
418	ctx->cpu = cpu;
419
420	switch (ltt_chan->header_type) {
421	case 1: /* compact */
422	if (event_id > 30)
423	ctx->rflags \|= LTT_RFLAG_EXTENDED;
424	break;
425	case 2: /* large */
426	if (event_id > 65534)
427	ctx->rflags \|= LTT_RFLAG_EXTENDED;
428	break;
429	default:
430	WARN_ON_ONCE(1);
431	}
432
433	ret = lib_ring_buffer_reserve(&client_config, ctx);
434	if (ret)
435	goto put;
436	ltt_write_event_header(&client_config, ctx, event_id);
437	return 0;
438	put:
439	lib_ring_buffer_put_cpu(&client_config);
440	return ret;
441	}
442
443	static
444	void ltt_event_commit(struct lib_ring_buffer_ctx *ctx)
445	{
446	lib_ring_buffer_commit(&client_config, ctx);
447	lib_ring_buffer_put_cpu(&client_config);
448	}
449
450	static
451	void ltt_event_write(struct lib_ring_buffer_ctx ctx, const void src,
452	size_t len)
453	{
454	lib_ring_buffer_write(&client_config, ctx, src, len);
455	}
456
457	static
458	wait_queue_head_t ltt_get_reader_wait_queue(struct channel chan)
459	{
460	return &chan->read_wait;
461	}
462
463	static
464	wait_queue_head_t ltt_get_hp_wait_queue(struct channel chan)
465	{
466	return &chan->hp_wait;
467	}
468
469	static
470	int ltt_is_finalized(struct channel *chan)
471	{
472	return lib_ring_buffer_channel_is_finalized(chan);
473	}
474
475	static
476	int ltt_is_disabled(struct channel *chan)
477	{
478	return lib_ring_buffer_channel_is_disabled(chan);
479	}
480
481	static struct ltt_transport ltt_relay_transport = {
482	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
483	.owner = THIS_MODULE,
484	.ops = {
485	.channel_create = _channel_create,
486	.channel_destroy = ltt_channel_destroy,
487	.buffer_read_open = ltt_buffer_read_open,
488	.buffer_read_close = ltt_buffer_read_close,
489	.event_reserve = ltt_event_reserve,
490	.event_commit = ltt_event_commit,
491	.event_write = ltt_event_write,
492	.packet_avail_size = NULL, /* Would be racy anyway */
493	.get_reader_wait_queue = ltt_get_reader_wait_queue,
494	.get_hp_wait_queue = ltt_get_hp_wait_queue,
495	.is_finalized = ltt_is_finalized,
496	.is_disabled = ltt_is_disabled,
497	},
498	};
499
500	static int __init ltt_ring_buffer_client_init(void)
501	{
502	/*
503	* This vmalloc sync all also takes care of the lib ring buffer
504	* vmalloc'd module pages when it is built as a module into LTTng.
505	*/
506	wrapper_vmalloc_sync_all();
507	printk(KERN_INFO "LTT : ltt ring buffer client init\n");
508	ltt_transport_register(&ltt_relay_transport);
509	return 0;
510	}
511
512	module_init(ltt_ring_buffer_client_init);
513
514	static void __exit ltt_ring_buffer_client_exit(void)
515	{
516	printk(KERN_INFO "LTT : ltt ring buffer client exit\n");
517	ltt_transport_unregister(&ltt_relay_transport);
518	}
519
520	module_exit(ltt_ring_buffer_client_exit);
521
522	MODULE_LICENSE("GPL and additional rights");
523	MODULE_AUTHOR("Mathieu Desnoyers");
524	MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
525	" client");