freebsd-nq/sys/powerpc/booke/swtch.S

/*-
 * Copyright (C) 2001 Benno Rice
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY Benno Rice ``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 TOOLS GMBH 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.
 *
 *	from: $NetBSD: locore.S,v 1.24 2000/05/31 05:09:17 thorpej Exp $
 *	from: $FreeBSD$
 *
 * $FreeBSD$
 */
/*-
 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
 * Copyright (C) 1995, 1996 TooLs GmbH.
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by TooLs GmbH.
 * 4. The name of TooLs GmbH may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``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 TOOLS GMBH 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.
 */

#include "assym.s"

#include <sys/syscall.h>

#include <machine/trap.h>
#include <machine/param.h>
#include <machine/asm.h>
#include <machine/spr.h>

/*
 * void cpu_throw(struct thread *old, struct thread *new)
 */
ENTRY(cpu_throw)
	mr	%r15, %r4
	b	cpu_switchin

/*
 * void cpu_switch(struct thread *old, struct thread *new, struct mutex *mtx);)
 *
 * Switch to a new thread saving the current state in the old thread.
 */
ENTRY(cpu_switch)
	stw	%r5, TD_LOCK(%r3)

	lwz	%r5, TD_PCB(%r3)	/* Get the old thread's PCB ptr */

	mr	%r12, %r2	
	stmw	%r12, PCB_CONTEXT(%r5)	/* Save the non-volatile GP regs.
					   These can now be used for scratch */

	mfcr	%r16			/* Save the condition register */
	stw	%r16, PCB_CR(%r5)
	mflr	%r16			/* Save the link register */
	stw	%r16, PCB_LR(%r5)
	mfctr	%r16
	stw	%r16, PCB_BOOKE_CTR(%r5)
	mfxer	%r16
	stw	%r16, PCB_BOOKE_XER(%r5)
	mfspr	%r16, SPR_DBCR0
	stw	%r16, PCB_BOOKE_DBCR0(%r5)

	stw	%r1, PCB_SP(%r5)	/* Save the stack pointer */

	mr	%r14, %r3		/* Copy the old thread ptr... */
	mr	%r15, %r4		/* and the new thread ptr in scratch */

	bl	pmap_deactivate		/* Deactivate the current pmap */

cpu_switchin:
	mr	%r3, %r15		/* Get new thread ptr */
	bl	pmap_activate		/* Activate the new address space */

	mfsprg	%r7, 0			/* Get the pcpu pointer */
	stw	%r15, PC_CURTHREAD(%r7)	/* Store new current thread */
	lwz	%r17, TD_PCB(%r15)	/* Store new current PCB */
	stw	%r17, PC_CURPCB(%r7)

	mr	%r3, %r17		/* Recover PCB ptr */
	lmw	%r12, PCB_CONTEXT(%r3)	/* Load the non-volatile GP regs */
	mr	%r2, %r12
	lwz	%r5, PCB_CR(%r3)	/* Load the condition register */
	mtcr	%r5
	lwz	%r5, PCB_LR(%r3)	/* Load the link register */
	mtlr	%r5
	lwz	%r5, PCB_BOOKE_CTR(%r3)
	mtctr	%r5
	lwz	%r5, PCB_BOOKE_XER(%r3)
	mtxer	%r5
	lwz	%r5, PCB_BOOKE_DBCR0(%r3)
	mtspr	SPR_DBCR0, %r5

	lwz	%r1, PCB_SP(%r3)	/* Load the stack pointer */
	blr

/*
 * savectx(pcb)
 * Update pcb, saving current processor state
 */
ENTRY(savectx)
	mr	%r12, %r2
	stmw	%r12, PCB_CONTEXT(%r3)	/* Save the non-volatile GP regs */
	mfcr	%r4			/* Save the condition register */
	stw	%r4, PCB_CONTEXT(%r3)
	blr

/*
 * fork_trampoline()
 * Set up the return from cpu_fork()
 */
ENTRY(fork_trampoline)
	lwz	%r3, CF_FUNC(%r1)
	lwz	%r4, CF_ARG0(%r1)
	lwz	%r5, CF_ARG1(%r1)
	bl	fork_exit
	addi	%r1, %r1, CF_SIZE-FSP	/* Allow 8 bytes in front of
					   trapframe to simulate FRAME_SETUP
					   does when allocating space for
					   a frame pointer/saved LR */
	b	trapexit