[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();
}

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;

		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);
	}

	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;

			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);
	}
	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 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
7514523f	1	/*
3d084699	2	* ltt-ring-buffer-client.h
7514523f MD	3	*
	4	* Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	5	*
3d084699	6	* LTTng lib ring buffer client template.
7514523f MD	7	*
	8	* Dual LGPL v2.1/GPL v2 license.
	9	*/
	10
	11	#include <linux/module.h>
c0e31d2e	12	#include <linux/types.h>
9115fbdc	13	#include "lib/bitfield.h"
b13f3ebe	14	#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
f3bc08c5	15	#include "wrapper/trace-clock.h"
c0e31d2e	16	#include "ltt-events.h"
7514523f	17	#include "ltt-tracer.h"
9115fbdc	18	#include "wrapper/ringbuffer/frontend_types.h"
7514523f	19
d793d5e1 MD	20	/*
	21	* Keep the natural field alignment for _each field_ within this structure if
	22	* you ever add/remove a field from this header. Packed attribute is not used
	23	* because gcc generates poor code on at least powerpc and mips. Don't ever
	24	* let gcc add padding between the structure elements.
	25	*/
9115fbdc	26
d793d5e1	27	struct packet_header {
9115fbdc	28	/* Trace packet header */
d793d5e1 MD	29	uint32_t magic; /*
	30	* Trace magic number.
	31	* contains endianness information.
	32	*/
1ec3f75a	33	uint8_t uuid[16];
d793d5e1	34	uint32_t stream_id;
9115fbdc MD	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;
d793d5e1 MD	50	};
	51
	52
881833e3 MD	53	static inline notrace u64 lib_ring_buffer_clock_read(struct channel *chan)
	54	{
	55	return trace_clock_read64();
	56	}
	57
f1676205 MD	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
881833e3 MD	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
881833e3	89	* @pre_header_padding: padding to add before the header (output)
881833e3 MD	90	* @ctx: reservation context
	91	*
	92	* Returns the event header size (including padding).
	93	*
881833e3 MD	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,
64c796d8	100	size_t *pre_header_padding,
881833e3 MD	101	struct lib_ring_buffer_ctx *ctx)
881833e3 MD	102	{
9115fbdc	103	struct ltt_channel *ltt_chan = channel_get_private(chan);
f1676205	104	struct ltt_event *event = ctx->priv;
881833e3 MD	105	size_t orig_offset = offset;
	106	size_t padding;
	107
9115fbdc MD	108	switch (ltt_chan->header_type) {
	109	case 1: /* compact */
	110	padding = lib_ring_buffer_align(offset, ltt_alignof(uint32_t));
	111	offset += padding;
64c796d8	112	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
9115fbdc MD	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);
64c796d8	128	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
9115fbdc MD	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
881833e3	138	}
9115fbdc MD	139	break;
9115fbdc MD	140	default:
64c796d8	141	WARN_ON_ONCE(1);
881833e3	142	}
f1676205 MD	143	offset += ctx_get_size(offset, event->ctx);
f1676205 MD	144	offset += ctx_get_size(offset, ltt_chan->ctx);
881833e3 MD	145
	146	*pre_header_padding = padding;
	147	return offset - orig_offset;
	148	}
	149
	150	#include "wrapper/ringbuffer/api.h"
	151
	152	extern
	153	void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
	154	struct lib_ring_buffer_ctx *ctx,
64c796d8	155	uint32_t event_id);
881833e3 MD	156
	157	/*
	158	* ltt_write_event_header
	159	*
	160	* Writes the event header to the offset (already aligned on 32-bits).
	161	*
	162	* @config: ring buffer instance configuration
	163	* @ctx: reservation context
4e1f08f4	164	* @event_id: event ID
881833e3 MD	165	*/
	166	static __inline__
	167	void ltt_write_event_header(const struct lib_ring_buffer_config *config,
	168	struct lib_ring_buffer_ctx *ctx,
64c796d8	169	uint32_t event_id)
881833e3	170	{
9115fbdc	171	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
f1676205	172	struct ltt_event *event = ctx->priv;
881833e3 MD	173
	174	if (unlikely(ctx->rflags))
	175	goto slow_path;
	176
9115fbdc MD	177	switch (ltt_chan->header_type) {
	178	case 1: /* compact */
	179	{
	180	uint32_t id_time = 0;
	181
4e1f08f4	182	bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
9115fbdc MD	183	bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
	184	lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
	185	break;
	186	}
	187	case 2: /* large */
	188	{
9115fbdc MD	189	uint32_t timestamp = (uint32_t) ctx->tsc;
	190
	191	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_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:
64c796d8	197	WARN_ON_ONCE(1);
9115fbdc	198	}
f1676205 MD	199
	200	ctx_record(ctx, ltt_chan, event->ctx);
	201	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
f1676205	202
9115fbdc	203	return;
881833e3 MD	204
881833e3 MD	205	slow_path:
4e1f08f4	206	ltt_write_event_header_slow(config, ctx, event_id);
881833e3 MD	207	}
881833e3 MD	208
881833e3	209	void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
64c796d8 MD	210	struct lib_ring_buffer_ctx *ctx,
64c796d8 MD	211	uint32_t event_id)
881833e3	212	{
9115fbdc	213	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
f1676205	214	struct ltt_event *event = ctx->priv;
9115fbdc MD	215
	216	switch (ltt_chan->header_type) {
	217	case 1: /* compact */
64c796d8	218	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
9115fbdc MD	219	uint32_t id_time = 0;
9115fbdc MD	220
4e1f08f4	221	bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
9115fbdc MD	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;
9115fbdc MD	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	}
881833e3	236	break;
9115fbdc MD	237	case 2: /* large */
9115fbdc MD	238	{
64c796d8	239	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
9115fbdc MD	240	uint32_t timestamp = (uint32_t) ctx->tsc;
	241
	242	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
	243	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t));
	244	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	245	} else {
64c796d8	246	uint16_t id = 65535;
9115fbdc MD	247	uint64_t timestamp = ctx->tsc;
9115fbdc MD	248
64c796d8	249	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
9115fbdc MD	250	/* Align extended struct on largest member */
9115fbdc MD	251	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
64c796d8	252	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
9115fbdc MD	253	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
	254	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	255	}
881833e3	256	break;
881833e3	257	}
9115fbdc	258	default:
64c796d8	259	WARN_ON_ONCE(1);
881833e3	260	}
f1676205 MD	261	ctx_record(ctx, ltt_chan, event->ctx);
f1676205 MD	262	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
881833e3 MD	263	}
881833e3 MD	264
7514523f MD	265	static const struct lib_ring_buffer_config client_config;
	266
	267	static u64 client_ring_buffer_clock_read(struct channel *chan)
	268	{
	269	return lib_ring_buffer_clock_read(chan);
	270	}
	271
1e2015dc	272	static
7514523f MD	273	size_t client_record_header_size(const struct lib_ring_buffer_config *config,
7514523f MD	274	struct channel *chan, size_t offset,
7514523f	275	size_t *pre_header_padding,
7514523f MD	276	struct lib_ring_buffer_ctx *ctx)
7514523f MD	277	{
64c796d8 MD	278	return record_header_size(config, chan, offset,
64c796d8 MD	279	pre_header_padding, ctx);
7514523f MD	280	}
	281
	282	/**
1c25284c	283	* client_packet_header_size - called on buffer-switch to a new sub-buffer
7514523f MD	284	*
	285	* Return header size without padding after the structure. Don't use packed
	286	* structure because gcc generates inefficient code on some architectures
	287	* (powerpc, mips..)
	288	*/
1c25284c	289	static size_t client_packet_header_size(void)
7514523f	290	{
9115fbdc	291	return offsetof(struct packet_header, ctx.header_end);
7514523f MD	292	}
	293
	294	static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
	295	unsigned int subbuf_idx)
	296	{
	297	struct channel *chan = buf->backend.chan;
1c25284c MD	298	struct packet_header *header =
1c25284c MD	299	(struct packet_header *)
7514523f MD	300	lib_ring_buffer_offset_address(&buf->backend,
7514523f MD	301	subbuf_idx * chan->backend.subbuf_size);
9115fbdc MD	302	struct ltt_channel *ltt_chan = channel_get_private(chan);
9115fbdc MD	303	struct ltt_session *session = ltt_chan->session;
7514523f	304
d793d5e1	305	header->magic = CTF_MAGIC_NUMBER;
1ec3f75a	306	memcpy(header->uuid, session->uuid.b, sizeof(session->uuid));
9115fbdc MD	307	header->stream_id = ltt_chan->id;
	308	header->ctx.timestamp_begin = tsc;
	309	header->ctx.timestamp_end = 0;
	310	header->ctx.events_discarded = 0;
	311	header->ctx.content_size = 0xFFFFFFFF; /* for debugging */
	312	header->ctx.packet_size = 0xFFFFFFFF;
	313	header->ctx.cpu_id = buf->backend.cpu;
7514523f MD	314	}
	315
	316	/*
	317	* offset is assumed to never be 0 here : never deliver a completely empty
	318	* subbuffer. data_size is between 1 and subbuf_size.
	319	*/
	320	static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
	321	unsigned int subbuf_idx, unsigned long data_size)
	322	{
	323	struct channel *chan = buf->backend.chan;
1c25284c MD	324	struct packet_header *header =
1c25284c MD	325	(struct packet_header *)
7514523f MD	326	lib_ring_buffer_offset_address(&buf->backend,
	327	subbuf_idx * chan->backend.subbuf_size);
	328	unsigned long records_lost = 0;
	329
9115fbdc	330	header->ctx.timestamp_end = tsc;
05d32c64 MD	331	header->ctx.content_size = data_size * CHAR_BIT; /* in bits */
05d32c64 MD	332	header->ctx.packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
7514523f MD	333	records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
	334	records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
	335	records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
9115fbdc	336	header->ctx.events_discarded = records_lost;
7514523f MD	337	}
	338
	339	static int client_buffer_create(struct lib_ring_buffer buf, void priv,
	340	int cpu, const char *name)
	341	{
1c25284c	342	return 0;
7514523f MD	343	}
	344
	345	static void client_buffer_finalize(struct lib_ring_buffer buf, void priv, int cpu)
	346	{
7514523f MD	347	}
	348
	349	static const struct lib_ring_buffer_config client_config = {
	350	.cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
	351	.cb.record_header_size = client_record_header_size,
1c25284c	352	.cb.subbuffer_header_size = client_packet_header_size,
7514523f MD	353	.cb.buffer_begin = client_buffer_begin,
	354	.cb.buffer_end = client_buffer_end,
	355	.cb.buffer_create = client_buffer_create,
	356	.cb.buffer_finalize = client_buffer_finalize,
	357
	358	.tsc_bits = 32,
	359	.alloc = RING_BUFFER_ALLOC_PER_CPU,
	360	.sync = RING_BUFFER_SYNC_PER_CPU,
3d084699	361	.mode = RING_BUFFER_MODE_TEMPLATE,
7514523f MD	362	.backend = RING_BUFFER_PAGE,
	363	.output = RING_BUFFER_SPLICE,
	364	.oops = RING_BUFFER_OOPS_CONSISTENCY,
	365	.ipi = RING_BUFFER_IPI_BARRIER,
	366	.wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
	367	};
	368
1e2015dc	369	static
1c25284c	370	struct channel _channel_create(const char name,
9115fbdc	371	struct ltt_channel ltt_chan, void buf_addr,
1c25284c MD	372	size_t subbuf_size, size_t num_subbuf,
	373	unsigned int switch_timer_interval,
	374	unsigned int read_timer_interval)
7514523f	375	{
9115fbdc	376	return channel_create(&client_config, name, ltt_chan, buf_addr,
7514523f MD	377	subbuf_size, num_subbuf, switch_timer_interval,
7514523f MD	378	read_timer_interval);
7514523f MD	379	}
7514523f MD	380
1e2015dc	381	static
7514523f MD	382	void ltt_channel_destroy(struct channel *chan)
7514523f MD	383	{
7514523f	384	channel_destroy(chan);
7514523f MD	385	}
7514523f MD	386
ad1c05e1 MD	387	static
	388	struct lib_ring_buffer ltt_buffer_read_open(struct channel chan)
	389	{
	390	struct lib_ring_buffer *buf;
	391	int cpu;
	392
1c25284c MD	393	for_each_channel_cpu(cpu, chan) {
1c25284c MD	394	buf = channel_get_ring_buffer(&client_config, chan, cpu);
ad1c05e1 MD	395	if (!lib_ring_buffer_open_read(buf))
	396	return buf;
	397	}
	398	return NULL;
	399	}
	400
	401	static
1c25284c	402	void ltt_buffer_read_close(struct lib_ring_buffer *buf)
ad1c05e1 MD	403	{
ad1c05e1 MD	404	lib_ring_buffer_release_read(buf);
1c25284c MD	405
	406	}
	407
c099397a	408	static
4e1f08f4	409	int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx,
64c796d8	410	uint32_t event_id)
1c25284c	411	{
64c796d8	412	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
1c25284c MD	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
64c796d8 MD	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
1c25284c MD	433	ret = lib_ring_buffer_reserve(&client_config, ctx);
	434	if (ret)
	435	goto put;
4e1f08f4 MD	436	ltt_write_event_header(&client_config, ctx, event_id);
4e1f08f4 MD	437	return 0;
1c25284c MD	438	put:
	439	lib_ring_buffer_put_cpu(&client_config);
	440	return ret;
ad1c05e1 MD	441	}
ad1c05e1 MD	442
c099397a	443	static
1c25284c MD	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
c099397a	450	static
e763dbf5 MD	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	}
1c25284c	456
c099397a MD	457	static
	458	wait_queue_head_t ltt_get_reader_wait_queue(struct ltt_channel chan)
	459	{
	460	return &chan->chan->read_wait;
	461	}
	462
7514523f	463	static struct ltt_transport ltt_relay_transport = {
3d084699	464	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
7514523f MD	465	.owner = THIS_MODULE,
7514523f MD	466	.ops = {
1c25284c MD	467	.channel_create = _channel_create,
1c25284c MD	468	.channel_destroy = ltt_channel_destroy,
ad1c05e1 MD	469	.buffer_read_open = ltt_buffer_read_open,
ad1c05e1 MD	470	.buffer_read_close = ltt_buffer_read_close,
1c25284c MD	471	.event_reserve = ltt_event_reserve,
1c25284c MD	472	.event_commit = ltt_event_commit,
e763dbf5	473	.event_write = ltt_event_write,
1ec3f75a	474	.packet_avail_size = NULL, /* Would be racy anyway */
c099397a	475	.get_reader_wait_queue = ltt_get_reader_wait_queue,
7514523f MD	476	},
	477	};
	478
3d084699	479	static int __init ltt_ring_buffer_client_init(void)
7514523f	480	{
a509e133 MD	481	/*
	482	* This vmalloc sync all also takes care of the lib ring buffer
	483	* vmalloc'd module pages when it is built as a module into LTTng.
	484	*/
6d2a620c	485	wrapper_vmalloc_sync_all();
7514523f MD	486	printk(KERN_INFO "LTT : ltt ring buffer client init\n");
	487	ltt_transport_register(&ltt_relay_transport);
	488	return 0;
	489	}
	490
1c25284c MD	491	module_init(ltt_ring_buffer_client_init);
1c25284c MD	492
3d084699	493	static void __exit ltt_ring_buffer_client_exit(void)
7514523f MD	494	{
	495	printk(KERN_INFO "LTT : ltt ring buffer client exit\n");
	496	ltt_transport_unregister(&ltt_relay_transport);
	497	}
	498
1c25284c MD	499	module_exit(ltt_ring_buffer_client_exit);
1c25284c MD	500
7514523f MD	501	MODULE_LICENSE("GPL and additional rights");
7514523f MD	502	MODULE_AUTHOR("Mathieu Desnoyers");
3d084699 MD	503	MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
3d084699 MD	504	" client");