path: root/bsps/powerpc/include/bsp/tictac.h

/**
 * @file
 *
 * @ingroup RTEMSBSPsPowerPCShared
 *
 * @brief Header file for tic-tac code.
 */

/*
 * Copyright (c) 2008 embedded brains GmbH.  All rights reserved.
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rtems.org/license/LICENSE.
 */

/**
 * @brief Reset reference ticks for tac().
 */
static inline void tic(void)
{
	uint32_t tmp;
	asm volatile (
		"mftb 0;"
		"stw 0, ppc_tic_tac@sdarel(13);"
		: "=r" (tmp)
	);
}

/**
 * @brief Returns number of ticks since last tic().
 */
static inline uint32_t tac(void)
{
	uint32_t ticks;
	uint32_t tmp;
	asm volatile (
		"mftb %0;"
		"lwz %1, ppc_tic_tac@sdarel(13);"
		"subf %0, %1, %0;"
		: "=r" (ticks), "=r" (tmp)
	);
	return ticks;
}

/**
 * @brief Reset reference ticks for bam().
 */
static inline void boom(void)
{
	uint32_t tmp;
	asm volatile (
		"mftb 0;"
		"stw 0, ppc_boom_bam@sdarel(13);"
		: "=r" (tmp)
	);
}

/**
 * @brief Returns number of ticks since last boom().
 */
static inline uint32_t bam(void)
{
	uint32_t ticks;
	uint32_t tmp;
	asm volatile (
		"mftb %0;"
		"lwz %1, ppc_boom_bam@sdarel(13);"
		"subf %0, %1, %0;"
		: "=r" (ticks), "=r" (tmp)
	);
	return ticks;
}