[ust.git] / libust / tracerconst.h

/*
 * Copyright (C) 2009 - Pierre-Marc Fournier (pierre-marc dot fournier at polymtl dot ca)
 * Copyright (C) 2008 - Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 */

#ifndef TRACERCONST_H
#define TRACERCONST_H

/* Hardcoded event headers
 *
 * event header for a trace with active heartbeat : 27 bits timestamps
 *
 * headers are 32-bits aligned. In order to insure such alignment, a dynamic per
 * trace alignment value must be done.
 *
 * Remember that the C compiler does align each member on the boundary
 * equivalent to their own size.
 *
 * As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
 * bytes aligned, so the buffer header and trace header are aligned.
 *
 * Event headers are aligned depending on the trace alignment option.
 *
 * Note using C structure bitfields for cross-endianness and portability
 * concerns.
 */

#define LTT_RESERVED_EVENTS	3
#define LTT_EVENT_BITS		5
#define LTT_FREE_EVENTS		((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
#define LTT_TSC_BITS		27
#define LTT_TSC_MASK		((1 << LTT_TSC_BITS) - 1)

struct ltt_event_header {
	u32 id_time;		/* 5 bits event id (MSB); 27 bits time (LSB) */
};

/* Reservation flags */
#define	LTT_RFLAG_ID			(1 << 0)
#define	LTT_RFLAG_ID_SIZE		(1 << 1)
#define	LTT_RFLAG_ID_SIZE_TSC		(1 << 2)

#define LTT_MAX_SMALL_SIZE              0xFFFFU

#endif /* TRACERCONST_H */
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2009 - Pierre-Marc Fournier (pierre-marc dot fournier at polymtl dot ca)
	3	* Copyright (C) 2008 - Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
	4	*
	5	* This library is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU Lesser General Public
	7	* License as published by the Free Software Foundation; either
	8	* version 2.1 of the License, or (at your option) any later version.
	9	*
	10	* This library is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	* Lesser General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU Lesser General Public
	16	* License along with this library; if not, write to the Free Software
	17	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	18	*/
	19
	20	#ifndef TRACERCONST_H
	21	#define TRACERCONST_H
	22
	23	/* Hardcoded event headers
	24	*
	25	* event header for a trace with active heartbeat : 27 bits timestamps
	26	*
	27	* headers are 32-bits aligned. In order to insure such alignment, a dynamic per
	28	* trace alignment value must be done.
	29	*
	30	* Remember that the C compiler does align each member on the boundary
	31	* equivalent to their own size.
	32	*
	33	* As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
	34	* bytes aligned, so the buffer header and trace header are aligned.
	35	*
	36	* Event headers are aligned depending on the trace alignment option.
	37	*
	38	* Note using C structure bitfields for cross-endianness and portability
	39	* concerns.
	40	*/
	41
	42	#define LTT_RESERVED_EVENTS 3
	43	#define LTT_EVENT_BITS 5
	44	#define LTT_FREE_EVENTS ((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
	45	#define LTT_TSC_BITS 27
	46	#define LTT_TSC_MASK ((1 << LTT_TSC_BITS) - 1)
	47
	48	struct ltt_event_header {
	49	u32 id_time; /* 5 bits event id (MSB); 27 bits time (LSB) */
	50	};
	51
	52	/* Reservation flags */
	53	#define LTT_RFLAG_ID (1 << 0)
	54	#define LTT_RFLAG_ID_SIZE (1 << 1)
	55	#define LTT_RFLAG_ID_SIZE_TSC (1 << 2)
	56
	57	#define LTT_MAX_SMALL_SIZE 0xFFFFU
	58
	59	#endif /* TRACERCONST_H */