todsg.h revision 03831d35f7499c87d51205817c93e9a8d42c4bae
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2000 by Sun Microsystems, Inc.
* All rights reserved.
*/
#ifndef _TODSG_H
#define _TODSG_H
#pragma ident "%Z%%M% %I% %E% SMI"
#ifdef __cplusplus
extern "C" {
#endif
/*
* Serengeti TOD (time of day) driver
*
* Serengeti does not have hardware TOD chip inside chassis. SC has
* a hardware TOD chip and maintains virtual TOD information for
* each domain. Domain accesses virtual TOD through SRAM on chosen
* IO board.
*/
#include <sys/time_impl.h>
/*
* IOSRAM used by virtual TOD
*
* +-------------------------------+
* | tod_magic |
* +-------------------------------+
* | tod_version |
* +-------------------------------+
* | tod_get_value |
* +-------------------------------+
* | tod_domain_skew |
* +-------------------------------+
* | tod_reserved |
* +-------------------------------+
* | tod_i_am_alive |
* +-------------------------------+
* | tod_timeout_period |
* +-------------------------------+
*
* For every struct member in IOSRAM except tod_domain_skew and tod_reserved,
* there are only one writer and one reader.
* tod_reserved (was tod_set_flag) is for backwards compatibility.
*
* reader read interval writer write interval
* ------------------------------------------------------------------------
* tod_get_value Solaris 1 second SC twice per second
* tod_domain_skew Solaris 1 second Solaris when needed
* SC (see following NOTE)
* tod_i_am_alive SC twice per second Solaris 1 second
* tod_timeout_period SC twice per second Solaris when needed
*
* NOTE: SC reads tod_domain_skew twice per second, notices if it
* changes, and always keeps the last observed value preserved
* in non-volatile storage.
*/
typedef struct _tod_iosram {
uint32_t tod_magic; /* magic number, always TODSG_MAGIC */
uint32_t tod_version; /* version number */
time_t tod_get_value; /* SC updates and Solaris reads */
time_t tod_domain_skew; /* Solaris updates and read */
uint32_t tod_reserved; /* Was tod_set_flag. No use */
uint32_t tod_i_am_alive; /* I'm alive! a.k.a. heartbeat */
uint32_t tod_timeout_period; /* time period to decide hard hang */
} tod_iosram_t;
#define TODSG_MAGIC 0x54443100 /* 'T','D', '1', \0 */
#define TODSG_VERSION_1 1
extern int todsg_use_sc;
#ifdef __cplusplus
}
#endif
#endif /* _TODSG_H */