[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 */
881833e3	137	}
9115fbdc MD	138	break;
9115fbdc MD	139	default:
64c796d8	140	WARN_ON_ONCE(1);
881833e3	141	}
f1676205 MD	142	offset += ctx_get_size(offset, event->ctx);
f1676205 MD	143	offset += ctx_get_size(offset, ltt_chan->ctx);
881833e3 MD	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,
64c796d8	154	uint32_t event_id);
881833e3 MD	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
4e1f08f4	163	* @event_id: event ID
881833e3 MD	164	*/
	165	static __inline__
	166	void ltt_write_event_header(const struct lib_ring_buffer_config *config,
	167	struct lib_ring_buffer_ctx *ctx,
64c796d8	168	uint32_t event_id)
881833e3	169	{
9115fbdc	170	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
f1676205	171	struct ltt_event *event = ctx->priv;
881833e3 MD	172
	173	if (unlikely(ctx->rflags))
	174	goto slow_path;
	175
9115fbdc MD	176	switch (ltt_chan->header_type) {
	177	case 1: /* compact */
	178	{
	179	uint32_t id_time = 0;
	180
4e1f08f4	181	bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
9115fbdc MD	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	{
9115fbdc MD	188	uint32_t timestamp = (uint32_t) ctx->tsc;
	189
	190	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
	191	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t));
	192	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	193	break;
	194	}
	195	default:
64c796d8	196	WARN_ON_ONCE(1);
9115fbdc	197	}
f1676205 MD	198
	199	ctx_record(ctx, ltt_chan, event->ctx);
	200	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
f1676205	201
9115fbdc	202	return;
881833e3 MD	203
881833e3 MD	204	slow_path:
4e1f08f4	205	ltt_write_event_header_slow(config, ctx, event_id);
881833e3 MD	206	}
881833e3 MD	207
881833e3	208	void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
64c796d8 MD	209	struct lib_ring_buffer_ctx *ctx,
64c796d8 MD	210	uint32_t event_id)
881833e3	211	{
9115fbdc	212	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
f1676205	213	struct ltt_event *event = ctx->priv;
9115fbdc MD	214
	215	switch (ltt_chan->header_type) {
	216	case 1: /* compact */
64c796d8	217	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
9115fbdc MD	218	uint32_t id_time = 0;
9115fbdc MD	219
4e1f08f4	220	bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
9115fbdc MD	221	bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
	222	lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
	223	} else {
	224	uint8_t id = 0;
9115fbdc MD	225	uint64_t timestamp = ctx->tsc;
	226
	227	bt_bitfield_write(&id, uint8_t, 0, 5, 31);
	228	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
	229	/* Align extended struct on largest member */
	230	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
	231	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
	232	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
	233	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	234	}
881833e3	235	break;
9115fbdc MD	236	case 2: /* large */
9115fbdc MD	237	{
64c796d8	238	if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC \| LTT_RFLAG_EXTENDED))) {
9115fbdc MD	239	uint32_t timestamp = (uint32_t) ctx->tsc;
	240
	241	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
	242	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t));
	243	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	244	} else {
64c796d8	245	uint16_t id = 65535;
9115fbdc MD	246	uint64_t timestamp = ctx->tsc;
9115fbdc MD	247
64c796d8	248	lib_ring_buffer_write(config, ctx, &id, sizeof(id));
9115fbdc MD	249	/* Align extended struct on largest member */
9115fbdc MD	250	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
64c796d8	251	lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
9115fbdc MD	252	lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
	253	lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
	254	}
881833e3	255	break;
881833e3	256	}
9115fbdc	257	default:
64c796d8	258	WARN_ON_ONCE(1);
881833e3	259	}
f1676205 MD	260	ctx_record(ctx, ltt_chan, event->ctx);
f1676205 MD	261	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
881833e3 MD	262	}
881833e3 MD	263
7514523f MD	264	static const struct lib_ring_buffer_config client_config;
	265
	266	static u64 client_ring_buffer_clock_read(struct channel *chan)
	267	{
	268	return lib_ring_buffer_clock_read(chan);
	269	}
	270
1e2015dc	271	static
7514523f MD	272	size_t client_record_header_size(const struct lib_ring_buffer_config *config,
7514523f MD	273	struct channel *chan, size_t offset,
7514523f	274	size_t *pre_header_padding,
7514523f MD	275	struct lib_ring_buffer_ctx *ctx)
7514523f MD	276	{
64c796d8 MD	277	return record_header_size(config, chan, offset,
64c796d8 MD	278	pre_header_padding, ctx);
7514523f MD	279	}
	280
	281	/**
1c25284c	282	* client_packet_header_size - called on buffer-switch to a new sub-buffer
7514523f MD	283	*
	284	* Return header size without padding after the structure. Don't use packed
	285	* structure because gcc generates inefficient code on some architectures
	286	* (powerpc, mips..)
	287	*/
1c25284c	288	static size_t client_packet_header_size(void)
7514523f	289	{
9115fbdc	290	return offsetof(struct packet_header, ctx.header_end);
7514523f MD	291	}
	292
	293	static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
	294	unsigned int subbuf_idx)
	295	{
	296	struct channel *chan = buf->backend.chan;
1c25284c MD	297	struct packet_header *header =
1c25284c MD	298	(struct packet_header *)
7514523f MD	299	lib_ring_buffer_offset_address(&buf->backend,
7514523f MD	300	subbuf_idx * chan->backend.subbuf_size);
9115fbdc MD	301	struct ltt_channel *ltt_chan = channel_get_private(chan);
9115fbdc MD	302	struct ltt_session *session = ltt_chan->session;
7514523f	303
d793d5e1	304	header->magic = CTF_MAGIC_NUMBER;
1ec3f75a	305	memcpy(header->uuid, session->uuid.b, sizeof(session->uuid));
9115fbdc MD	306	header->stream_id = ltt_chan->id;
	307	header->ctx.timestamp_begin = tsc;
	308	header->ctx.timestamp_end = 0;
	309	header->ctx.events_discarded = 0;
	310	header->ctx.content_size = 0xFFFFFFFF; /* for debugging */
	311	header->ctx.packet_size = 0xFFFFFFFF;
	312	header->ctx.cpu_id = buf->backend.cpu;
7514523f MD	313	}
	314
	315	/*
	316	* offset is assumed to never be 0 here : never deliver a completely empty
	317	* subbuffer. data_size is between 1 and subbuf_size.
	318	*/
	319	static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
	320	unsigned int subbuf_idx, unsigned long data_size)
	321	{
	322	struct channel *chan = buf->backend.chan;
1c25284c MD	323	struct packet_header *header =
1c25284c MD	324	(struct packet_header *)
7514523f MD	325	lib_ring_buffer_offset_address(&buf->backend,
	326	subbuf_idx * chan->backend.subbuf_size);
	327	unsigned long records_lost = 0;
	328
9115fbdc	329	header->ctx.timestamp_end = tsc;
05d32c64 MD	330	header->ctx.content_size = data_size * CHAR_BIT; /* in bits */
05d32c64 MD	331	header->ctx.packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
7514523f MD	332	records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
	333	records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
	334	records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
9115fbdc	335	header->ctx.events_discarded = records_lost;
7514523f MD	336	}
	337
	338	static int client_buffer_create(struct lib_ring_buffer buf, void priv,
	339	int cpu, const char *name)
	340	{
1c25284c	341	return 0;
7514523f MD	342	}
	343
	344	static void client_buffer_finalize(struct lib_ring_buffer buf, void priv, int cpu)
	345	{
7514523f MD	346	}
	347
	348	static const struct lib_ring_buffer_config client_config = {
	349	.cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
	350	.cb.record_header_size = client_record_header_size,
1c25284c	351	.cb.subbuffer_header_size = client_packet_header_size,
7514523f MD	352	.cb.buffer_begin = client_buffer_begin,
	353	.cb.buffer_end = client_buffer_end,
	354	.cb.buffer_create = client_buffer_create,
	355	.cb.buffer_finalize = client_buffer_finalize,
	356
	357	.tsc_bits = 32,
	358	.alloc = RING_BUFFER_ALLOC_PER_CPU,
	359	.sync = RING_BUFFER_SYNC_PER_CPU,
3d084699	360	.mode = RING_BUFFER_MODE_TEMPLATE,
7514523f MD	361	.backend = RING_BUFFER_PAGE,
	362	.output = RING_BUFFER_SPLICE,
	363	.oops = RING_BUFFER_OOPS_CONSISTENCY,
	364	.ipi = RING_BUFFER_IPI_BARRIER,
	365	.wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
	366	};
	367
1e2015dc	368	static
1c25284c	369	struct channel _channel_create(const char name,
9115fbdc	370	struct ltt_channel ltt_chan, void buf_addr,
1c25284c MD	371	size_t subbuf_size, size_t num_subbuf,
	372	unsigned int switch_timer_interval,
	373	unsigned int read_timer_interval)
7514523f	374	{
9115fbdc	375	return channel_create(&client_config, name, ltt_chan, buf_addr,
7514523f MD	376	subbuf_size, num_subbuf, switch_timer_interval,
7514523f MD	377	read_timer_interval);
7514523f MD	378	}
7514523f MD	379
1e2015dc	380	static
7514523f MD	381	void ltt_channel_destroy(struct channel *chan)
7514523f MD	382	{
7514523f	383	channel_destroy(chan);
7514523f MD	384	}
7514523f MD	385
ad1c05e1 MD	386	static
	387	struct lib_ring_buffer ltt_buffer_read_open(struct channel chan)
	388	{
	389	struct lib_ring_buffer *buf;
	390	int cpu;
	391
1c25284c MD	392	for_each_channel_cpu(cpu, chan) {
1c25284c MD	393	buf = channel_get_ring_buffer(&client_config, chan, cpu);
ad1c05e1 MD	394	if (!lib_ring_buffer_open_read(buf))
	395	return buf;
	396	}
	397	return NULL;
	398	}
	399
	400	static
1c25284c	401	void ltt_buffer_read_close(struct lib_ring_buffer *buf)
ad1c05e1 MD	402	{
ad1c05e1 MD	403	lib_ring_buffer_release_read(buf);
1c25284c MD	404	}
1c25284c MD	405
c099397a	406	static
4e1f08f4	407	int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx,
64c796d8	408	uint32_t event_id)
1c25284c	409	{
64c796d8	410	struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
1c25284c MD	411	int ret, cpu;
	412
	413	cpu = lib_ring_buffer_get_cpu(&client_config);
	414	if (cpu < 0)
	415	return -EPERM;
	416	ctx->cpu = cpu;
	417
64c796d8 MD	418	switch (ltt_chan->header_type) {
	419	case 1: /* compact */
	420	if (event_id > 30)
	421	ctx->rflags \|= LTT_RFLAG_EXTENDED;
	422	break;
	423	case 2: /* large */
	424	if (event_id > 65534)
	425	ctx->rflags \|= LTT_RFLAG_EXTENDED;
	426	break;
	427	default:
	428	WARN_ON_ONCE(1);
	429	}
	430
1c25284c MD	431	ret = lib_ring_buffer_reserve(&client_config, ctx);
	432	if (ret)
	433	goto put;
4e1f08f4 MD	434	ltt_write_event_header(&client_config, ctx, event_id);
4e1f08f4 MD	435	return 0;
1c25284c MD	436	put:
	437	lib_ring_buffer_put_cpu(&client_config);
	438	return ret;
ad1c05e1 MD	439	}
ad1c05e1 MD	440
c099397a	441	static
1c25284c MD	442	void ltt_event_commit(struct lib_ring_buffer_ctx *ctx)
	443	{
	444	lib_ring_buffer_commit(&client_config, ctx);
	445	lib_ring_buffer_put_cpu(&client_config);
	446	}
	447
c099397a	448	static
e763dbf5 MD	449	void ltt_event_write(struct lib_ring_buffer_ctx ctx, const void src,
	450	size_t len)
	451	{
	452	lib_ring_buffer_write(&client_config, ctx, src, len);
	453	}
1c25284c	454
c099397a MD	455	static
	456	wait_queue_head_t ltt_get_reader_wait_queue(struct ltt_channel chan)
	457	{
	458	return &chan->chan->read_wait;
	459	}
	460
7514523f	461	static struct ltt_transport ltt_relay_transport = {
3d084699	462	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
7514523f MD	463	.owner = THIS_MODULE,
7514523f MD	464	.ops = {
1c25284c MD	465	.channel_create = _channel_create,
1c25284c MD	466	.channel_destroy = ltt_channel_destroy,
ad1c05e1 MD	467	.buffer_read_open = ltt_buffer_read_open,
ad1c05e1 MD	468	.buffer_read_close = ltt_buffer_read_close,
1c25284c MD	469	.event_reserve = ltt_event_reserve,
1c25284c MD	470	.event_commit = ltt_event_commit,
e763dbf5	471	.event_write = ltt_event_write,
1ec3f75a	472	.packet_avail_size = NULL, /* Would be racy anyway */
c099397a	473	.get_reader_wait_queue = ltt_get_reader_wait_queue,
7514523f MD	474	},
	475	};
	476
3d084699	477	static int __init ltt_ring_buffer_client_init(void)
7514523f	478	{
a509e133 MD	479	/*
	480	* This vmalloc sync all also takes care of the lib ring buffer
	481	* vmalloc'd module pages when it is built as a module into LTTng.
	482	*/
6d2a620c	483	wrapper_vmalloc_sync_all();
7514523f MD	484	printk(KERN_INFO "LTT : ltt ring buffer client init\n");
	485	ltt_transport_register(&ltt_relay_transport);
	486	return 0;
	487	}
	488
1c25284c MD	489	module_init(ltt_ring_buffer_client_init);
1c25284c MD	490
3d084699	491	static void __exit ltt_ring_buffer_client_exit(void)
7514523f MD	492	{
	493	printk(KERN_INFO "LTT : ltt ring buffer client exit\n");
	494	ltt_transport_unregister(&ltt_relay_transport);
	495	}
	496
1c25284c MD	497	module_exit(ltt_ring_buffer_client_exit);
1c25284c MD	498
7514523f MD	499	MODULE_LICENSE("GPL and additional rights");
7514523f MD	500	MODULE_AUTHOR("Mathieu Desnoyers");
3d084699 MD	501	MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
3d084699 MD	502	" client");