[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.
 */

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();
}

/*
 * 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);
	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);
	}

	*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);

	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;

		lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_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);
	}
	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);

	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;

			lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_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);
	}
}

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 ltt_channel *chan)
{
	return &chan->chan->read_wait;
}

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,
	},
};

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
	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	/*
	59	* record_header_size - Calculate the header size and padding necessary.
	60	* @config: ring buffer instance configuration
	61	* @chan: channel
	62	* @offset: offset in the write buffer
	63	* @pre_header_padding: padding to add before the header (output)
	64	* @ctx: reservation context
	65	*
	66	* Returns the event header size (including padding).
	67	*
	68	* The payload must itself determine its own alignment from the biggest type it
	69	* contains.
	70	*/
	71	static __inline__
	72	unsigned char record_header_size(const struct lib_ring_buffer_config *config,
	73	struct channel *chan, size_t offset,
	74	size_t *pre_header_padding,
	75	struct lib_ring_buffer_ctx *ctx)
	76	{
	77	struct ltt_channel *ltt_chan = channel_get_private(chan);
	78	size_t orig_offset = offset;
	79	size_t padding;
	80
	81	switch (ltt_chan->header_type) {
	82	case 1: /* compact */
	83	padding = lib_ring_buffer_align(offset, ltt_alignof(uint32_t));
	84	offset += padding;
	85	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
	86	offset += sizeof(uint32_t); /* id and timestamp */
	87	} else {
	88	/* Minimum space taken by 5-bit id */
	89	offset += sizeof(uint8_t);
	90	/* Align extended struct on largest member */
	91	offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
	92	offset += sizeof(uint32_t); /* id */
	93	offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
	94	offset += sizeof(uint64_t); /* timestamp */
	95	}
	96	break;
	97	case 2: /* large */
	98	padding = lib_ring_buffer_align(offset, ltt_alignof(uint16_t));
	99	offset += padding;
	100	offset += sizeof(uint16_t);
	101	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
	102	offset += lib_ring_buffer_align(offset, ltt_alignof(uint32_t));
	103	offset += sizeof(uint32_t); /* timestamp */
	104	} else {
	105	/* Align extended struct on largest member */
	106	offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
	107	offset += sizeof(uint32_t); /* id */
	108	offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
	109	offset += sizeof(uint64_t); /* timestamp */
	110
	111	}
	112	break;
	113	default:
	114	WARN_ON_ONCE(1);
	115	}
	116
	117	*pre_header_padding = padding;
	118	return offset - orig_offset;
	119	}
	120
	121	#include "wrapper/ringbuffer/api.h"
	122
	123	extern
	124	void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
	125	struct lib_ring_buffer_ctx *ctx,
	126	uint32_t event_id);
	127
	128	/*
	129	* ltt_write_event_header
	130	*
	131	* Writes the event header to the offset (already aligned on 32-bits).
	132	*
	133	* @config: ring buffer instance configuration
	134	* @ctx: reservation context
	135	* @event_id: event ID
	136	*/
	137	static __inline__
	138	void ltt_write_event_header(const struct lib_ring_buffer_config *config,
	139	struct lib_ring_buffer_ctx *ctx,
	140	uint32_t event_id)
	141	{
	142	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
	143
	144	if (unlikely(ctx->rflags))
	145	goto slow_path;
	146
	147	switch (ltt_chan->header_type) {
	148	case 1: /* compact */
	149	{
	150	uint32_t id_time = 0;
	151
	152	bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
	153	bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
	154	lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
	155	break;
	156	}
	157	case 2: /* large */
	158	{
	159	uint32_t timestamp = (uint32_t) ctx->tsc;
	160
	161	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
	162	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t));
	163	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	164	break;
	165	}
	166	default:
	167	WARN_ON_ONCE(1);
	168	}
	169	return;
	170
	171	slow_path:
	172	ltt_write_event_header_slow(config, ctx, event_id);
	173	}
	174
	175	void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
	176	struct lib_ring_buffer_ctx *ctx,
	177	uint32_t event_id)
	178	{
	179	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
	180
	181	switch (ltt_chan->header_type) {
	182	case 1: /* compact */
	183	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
	184	uint32_t id_time = 0;
	185
	186	bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
	187	bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
	188	lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
	189	} else {
	190	uint8_t id = 0;
	191	uint64_t timestamp = ctx->tsc;
	192
	193	bt_bitfield_write(&id, uint8_t, 0, 5, 31);
	194	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
	195	/* Align extended struct on largest member */
	196	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
	197	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
	198	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
	199	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	200	}
	201	break;
	202	case 2: /* large */
	203	{
	204	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
	205	uint32_t timestamp = (uint32_t) ctx->tsc;
	206
	207	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
	208	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t));
	209	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	210	} else {
	211	uint16_t id = 65535;
	212	uint64_t timestamp = ctx->tsc;
	213
	214	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
	215	/* Align extended struct on largest member */
	216	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
	217	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
	218	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
	219	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	220	}
	221	break;
	222	}
	223	default:
	224	WARN_ON_ONCE(1);
	225	}
	226	}
	227
	228	static const struct lib_ring_buffer_config client_config;
	229
	230	static u64 client_ring_buffer_clock_read(struct channel *chan)
	231	{
	232	return lib_ring_buffer_clock_read(chan);
	233	}
	234
	235	static
	236	size_t client_record_header_size(const struct lib_ring_buffer_config *config,
	237	struct channel *chan, size_t offset,
	238	size_t *pre_header_padding,
	239	struct lib_ring_buffer_ctx *ctx)
	240	{
	241	return record_header_size(config, chan, offset,
	242	pre_header_padding, ctx);
	243	}
	244
	245	/**
	246	* client_packet_header_size - called on buffer-switch to a new sub-buffer
	247	*
	248	* Return header size without padding after the structure. Don't use packed
	249	* structure because gcc generates inefficient code on some architectures
	250	* (powerpc, mips..)
	251	*/
	252	static size_t client_packet_header_size(void)
	253	{
	254	return offsetof(struct packet_header, ctx.header_end);
	255	}
	256
	257	static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
	258	unsigned int subbuf_idx)
	259	{
	260	struct channel *chan = buf->backend.chan;
	261	struct packet_header *header =
	262	(struct packet_header *)
	263	lib_ring_buffer_offset_address(&buf->backend,
	264	subbuf_idx * chan->backend.subbuf_size);
	265	struct ltt_channel *ltt_chan = channel_get_private(chan);
	266	struct ltt_session *session = ltt_chan->session;
	267
	268	header->magic = CTF_MAGIC_NUMBER;
	269	memcpy(header->uuid, session->uuid.b, sizeof(session->uuid));
	270	header->stream_id = ltt_chan->id;
	271	header->ctx.timestamp_begin = tsc;
	272	header->ctx.timestamp_end = 0;
	273	header->ctx.events_discarded = 0;
	274	header->ctx.content_size = 0xFFFFFFFF; /* for debugging */
	275	header->ctx.packet_size = 0xFFFFFFFF;
	276	header->ctx.cpu_id = buf->backend.cpu;
	277	}
	278
	279	/*
	280	* offset is assumed to never be 0 here : never deliver a completely empty
	281	* subbuffer. data_size is between 1 and subbuf_size.
	282	*/
	283	static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
	284	unsigned int subbuf_idx, unsigned long data_size)
	285	{
	286	struct channel *chan = buf->backend.chan;
	287	struct packet_header *header =
	288	(struct packet_header *)
	289	lib_ring_buffer_offset_address(&buf->backend,
	290	subbuf_idx * chan->backend.subbuf_size);
	291	unsigned long records_lost = 0;
	292
	293	header->ctx.timestamp_end = tsc;
	294	header->ctx.content_size = data_size * CHAR_BIT; /* in bits */
	295	header->ctx.packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
	296	records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
	297	records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
	298	records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
	299	header->ctx.events_discarded = records_lost;
	300	}
	301
	302	static int client_buffer_create(struct lib_ring_buffer buf, void priv,
	303	int cpu, const char *name)
	304	{
	305	return 0;
	306	}
	307
	308	static void client_buffer_finalize(struct lib_ring_buffer buf, void priv, int cpu)
	309	{
	310	}
	311
	312	static const struct lib_ring_buffer_config client_config = {
	313	.cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
	314	.cb.record_header_size = client_record_header_size,
	315	.cb.subbuffer_header_size = client_packet_header_size,
	316	.cb.buffer_begin = client_buffer_begin,
	317	.cb.buffer_end = client_buffer_end,
	318	.cb.buffer_create = client_buffer_create,
	319	.cb.buffer_finalize = client_buffer_finalize,
	320
	321	.tsc_bits = 32,
	322	.alloc = RING_BUFFER_ALLOC_PER_CPU,
	323	.sync = RING_BUFFER_SYNC_PER_CPU,
	324	.mode = RING_BUFFER_MODE_TEMPLATE,
	325	.backend = RING_BUFFER_PAGE,
	326	.output = RING_BUFFER_SPLICE,
	327	.oops = RING_BUFFER_OOPS_CONSISTENCY,
	328	.ipi = RING_BUFFER_IPI_BARRIER,
	329	.wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
	330	};
	331
	332	static
	333	struct channel _channel_create(const char name,
	334	struct ltt_channel ltt_chan, void buf_addr,
	335	size_t subbuf_size, size_t num_subbuf,
	336	unsigned int switch_timer_interval,
	337	unsigned int read_timer_interval)
	338	{
	339	return channel_create(&client_config, name, ltt_chan, buf_addr,
	340	subbuf_size, num_subbuf, switch_timer_interval,
	341	read_timer_interval);
	342	}
	343
	344	static
	345	void ltt_channel_destroy(struct channel *chan)
	346	{
	347	channel_destroy(chan);
	348	}
	349
	350	static
	351	struct lib_ring_buffer ltt_buffer_read_open(struct channel chan)
	352	{
	353	struct lib_ring_buffer *buf;
	354	int cpu;
	355
	356	for_each_channel_cpu(cpu, chan) {
	357	buf = channel_get_ring_buffer(&client_config, chan, cpu);
	358	if (!lib_ring_buffer_open_read(buf))
	359	return buf;
	360	}
	361	return NULL;
	362	}
	363
	364	static
	365	void ltt_buffer_read_close(struct lib_ring_buffer *buf)
	366	{
	367	lib_ring_buffer_release_read(buf);
	368
	369	}
	370
	371	static
	372	int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx,
	373	uint32_t event_id)
	374	{
	375	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
	376	int ret, cpu;
	377
	378	cpu = lib_ring_buffer_get_cpu(&client_config);
	379	if (cpu < 0)
	380	return -EPERM;
	381	ctx->cpu = cpu;
	382
	383	switch (ltt_chan->header_type) {
	384	case 1: /* compact */
	385	if (event_id > 30)
	386	ctx->rflags \|= LTT_RFLAG_EXTENDED;
	387	break;
	388	case 2: /* large */
	389	if (event_id > 65534)
	390	ctx->rflags \|= LTT_RFLAG_EXTENDED;
	391	break;
	392	default:
	393	WARN_ON_ONCE(1);
	394	}
	395
	396	ret = lib_ring_buffer_reserve(&client_config, ctx);
	397	if (ret)
	398	goto put;
	399	ltt_write_event_header(&client_config, ctx, event_id);
	400	return 0;
	401	put:
	402	lib_ring_buffer_put_cpu(&client_config);
	403	return ret;
	404	}
	405
	406	static
	407	void ltt_event_commit(struct lib_ring_buffer_ctx *ctx)
	408	{
	409	lib_ring_buffer_commit(&client_config, ctx);
	410	lib_ring_buffer_put_cpu(&client_config);
	411	}
	412
	413	static
	414	void ltt_event_write(struct lib_ring_buffer_ctx ctx, const void src,
	415	size_t len)
	416	{
	417	lib_ring_buffer_write(&client_config, ctx, src, len);
	418	}
	419
	420	static
	421	wait_queue_head_t ltt_get_reader_wait_queue(struct ltt_channel chan)
	422	{
	423	return &chan->chan->read_wait;
	424	}
	425
	426	static struct ltt_transport ltt_relay_transport = {
	427	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
	428	.owner = THIS_MODULE,
	429	.ops = {
	430	.channel_create = _channel_create,
	431	.channel_destroy = ltt_channel_destroy,
	432	.buffer_read_open = ltt_buffer_read_open,
	433	.buffer_read_close = ltt_buffer_read_close,
	434	.event_reserve = ltt_event_reserve,
	435	.event_commit = ltt_event_commit,
	436	.event_write = ltt_event_write,
	437	.packet_avail_size = NULL, /* Would be racy anyway */
	438	.get_reader_wait_queue = ltt_get_reader_wait_queue,
	439	},
	440	};
	441
	442	static int __init ltt_ring_buffer_client_init(void)
	443	{
	444	/*
	445	* This vmalloc sync all also takes care of the lib ring buffer
	446	* vmalloc'd module pages when it is built as a module into LTTng.
	447	*/
	448	wrapper_vmalloc_sync_all();
	449	printk(KERN_INFO "LTT : ltt ring buffer client init\n");
	450	ltt_transport_register(&ltt_relay_transport);
	451	return 0;
	452	}
	453
	454	module_init(ltt_ring_buffer_client_init);
	455
	456	static void __exit ltt_ring_buffer_client_exit(void)
	457	{
	458	printk(KERN_INFO "LTT : ltt ring buffer client exit\n");
	459	ltt_transport_unregister(&ltt_relay_transport);
	460	}
	461
	462	module_exit(ltt_ring_buffer_client_exit);
	463
	464	MODULE_LICENSE("GPL and additional rights");
	465	MODULE_AUTHOR("Mathieu Desnoyers");
	466	MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
	467	" client");