104 lines
3.4 KiB
C
104 lines
3.4 KiB
C
/*
|
|
* Copyright (c) 2015, SICS Swedish ICT.
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the name of the Institute nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* This file is part of the Contiki operating system.
|
|
*
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* TSCH 5-Byte Absolute Slot Number (ASN) management
|
|
* \author
|
|
* Simon Duquennoy <simonduq@sics.se>
|
|
*
|
|
*/
|
|
|
|
/**
|
|
* \addtogroup tsch
|
|
* @{
|
|
*/
|
|
|
|
#ifndef __TSCH_ASN_H__
|
|
#define __TSCH_ASN_H__
|
|
|
|
/************ Types ***********/
|
|
|
|
/* The ASN is an absolute slot number over 5 bytes. */
|
|
struct tsch_asn_t {
|
|
uint32_t ls4b; /* least significant 4 bytes */
|
|
uint8_t ms1b; /* most significant 1 byte */
|
|
};
|
|
|
|
/* For quick modulo operation on ASN */
|
|
struct tsch_asn_divisor_t {
|
|
uint16_t val; /* Divisor value */
|
|
uint16_t asn_ms1b_remainder; /* Remainder of the operation 0x100000000 / val */
|
|
};
|
|
|
|
/************ Macros **********/
|
|
|
|
/* Initialize ASN */
|
|
#define TSCH_ASN_INIT(asn, ms1b_, ls4b_) do { \
|
|
(asn).ms1b = (ms1b_); \
|
|
(asn).ls4b = (ls4b_); \
|
|
} while(0);
|
|
|
|
/* Increment an ASN by inc (32 bits) */
|
|
#define TSCH_ASN_INC(asn, inc) do { \
|
|
uint32_t new_ls4b = (asn).ls4b + (inc); \
|
|
if(new_ls4b < (asn).ls4b) { (asn).ms1b++; } \
|
|
(asn).ls4b = new_ls4b; \
|
|
} while(0);
|
|
|
|
/* Decrement an ASN by inc (32 bits) */
|
|
#define TSCH_ASN_DEC(asn, dec) do { \
|
|
uint32_t new_ls4b = (asn).ls4b - (dec); \
|
|
if(new_ls4b > (asn).ls4b) { (asn).ms1b--; } \
|
|
(asn).ls4b = new_ls4b; \
|
|
} while(0);
|
|
|
|
/* Returns the 32-bit diff between asn1 and asn2 */
|
|
#define TSCH_ASN_DIFF(asn1, asn2) \
|
|
((asn1).ls4b - (asn2).ls4b)
|
|
|
|
/* Initialize a struct asn_divisor_t */
|
|
#define TSCH_ASN_DIVISOR_INIT(div, val_) do { \
|
|
(div).val = (val_); \
|
|
(div).asn_ms1b_remainder = ((0xffffffff % (val_)) + 1) % (val_); \
|
|
} while(0);
|
|
|
|
/* Returns the result (16 bits) of a modulo operation on ASN,
|
|
* with divisor being a struct asn_divisor_t */
|
|
#define TSCH_ASN_MOD(asn, div) \
|
|
((uint16_t)((asn).ls4b % (div).val) \
|
|
+ (uint16_t)((asn).ms1b * (div).asn_ms1b_remainder % (div).val)) \
|
|
% (div).val
|
|
|
|
#endif /* __TSCH_ASN_H__ */
|
|
/** @} */
|