/*	$OpenBSD: locore.S,v 1.12 2005/11/24 12:08:16 pedro Exp $	*/
/*	$NetBSD: locore.S,v 1.2 1996/10/16 19:33:09 ws Exp $	*/

/*
 * 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.h"

#include <sys/syscall.h>

#include <machine/asm.h>
#include <machine/param.h>
#include <machine/pmap.h>
#include <machine/psl.h>
#include <machine/trap.h>

/*
 * Globals
 */
	.globl	_C_LABEL(esym),_C_LABEL(proc0paddr)
	.type	_C_LABEL(esym),@object
	.type	_C_LABEL(proc0paddr),@object
	.data
_C_LABEL(esym):		.long	0	/* end of symbol table */
_C_LABEL(proc0paddr):	.long	0	/* proc0 p_addr */
idle_u:			.long	0	/* fake uarea during idle after exit */

/*
 * Startup entry
 */
_ENTRY(_C_LABEL(kernel_text))
_ENTRY(_ASM_LABEL(start))
/*
 * Arguments to start for mvmeppc
 * r1 - stack provided by firmware/bootloader
 * r3 - boot flags
 * r4 - boot device
 * r5 - firmware pointer (NULL for PPC1bug)
 * r6 - arg list (NULL)
 * r7 - length (0)
 * r8 - end of symbol table
 */
	.globl	start
	.type start,@function
start:
	li	%r0,0
	mtmsr	%r0			/* Disable FPU/MMU/exceptions */
	isync

	/* save boot device and flags */
	lis	%r9, _C_LABEL(boothowto)@ha
	stw	%r3, _C_LABEL(boothowto)@l(%r9)
	lis	%r9, _C_LABEL(bootdev)@ha
	stw	%r4, _C_LABEL(bootdev)@l(%r9)

/* compute end of kernel memory */
#if defined(DDB)
	lis	%r9,_C_LABEL(esym)@ha
	stw	%r8,_C_LABEL(esym)@l(%r9)	/* save for symbol handling */
#else
	lis	%r8,_end@ha
	addi	%r8,%r8,_end@l
#endif
	li	%r9,PGOFSET
	add	%r8,%r8,%r9
	andc	%r8,%r8,%r9
	lis	%r9,idle_u@ha
	stw	%r8,idle_u@l(%r9)
	addi	%r8,%r8,USPACE		/* space for idle_u */
	lis	%r9,_C_LABEL(proc0paddr)@ha
	stw	%r8,_C_LABEL(proc0paddr)@l(%r9)
	addi	%r1,%r8,USPACE-FRAMELEN	/* stackpointer for proc0 */
	mr	%r4,%r1			/* end of mem reserved for kernel */
	li	%r0,0
	stwu	%r0,-16(%r1)		/* end of stack chain */

	lis	%r3,start@ha
	addi	%r3,%r3,start@l
	mr	%r5,%r6			/* args string */
	bl	_C_LABEL(initppc)
	bl	_C_LABEL(main)
	b	_C_LABEL(PPC1_exit)

/*
 * No processes are runnable, so loop waiting for one.
 * Separate label here for accounting purposes.
 */
_C_LABEL(idle):
	mfmsr	%r3
	/* disable interrupts while manipulating runque */
	andi.	%r3,%r3,~PSL_EE@l
	mtmsr	%r3

	lis	%r8,_C_LABEL(whichqs)@ha
	lwz	%r9,_C_LABEL(whichqs)@l(%r8)

	or.	%r9,%r9,%r9
	bne-	_C_LABEL(sw1)			/* at least one queue non-empty */

	ori	%r3,%r3,PSL_EE		/* reenable ints again */
	mtmsr	%r3
	isync
	sync
	/* low power mode */
	mfmsr	%r3
	oris	%r3, %r3, PSL_POW@h
	mtmsr	%r3
	isync

/* May do some power saving here? */

	b	_C_LABEL(idle)

/*
 * switchexit gets called from cpu_exit to free the user structure
 * and kernel stack of the current process.
 */
_ENTRY(_C_LABEL(switchexit))
/* First switch to the idle pcb/kernel stack */
	lis	%r6,idle_u@ha
	lwz	%r6,idle_u@l(%r6)
	lis	%r7,_C_LABEL(curpcb)@ha
	stw	%r6,_C_LABEL(curpcb)@l(%r7)
	addi	%r1,%r6,USPACE-16	/* 16 bytes are reserved at stack top */
	/*
	 * Schedule the vmspace and stack to be freed (the proc arg is
	 * already in r3).
	 */
	bl	_C_LABEL(exit2)

	/* Fall through to cpu_switch to actually select another proc */
	li	%r3,0			/* indicate exited process */

/* Fall through to cpu_switch to actually select another proc */

/*
 * void cpu_switch(struct proc *p)
 * Find a runnable process and switch to it.
 */
_ENTRY(_C_LABEL(cpu_switch))
	mflr	%r0			/* save lr */
	stw	%r0,4(%r1)
	stwu	%r1,-16(%r1)
	stw	%r31,12(%r1)
	stw	%r30,8(%r1)

	mr	%r30,%r3
	lis	%r3,_C_LABEL(curproc)@ha
	li	%r31,0
	/* Zero to not accumulate cpu time */
	stw	%r31,_C_LABEL(curproc)@l(%r3)
	lis	%r3,_C_LABEL(curpcb)@ha
	lwz	%r31,_C_LABEL(curpcb)@l(%r3)

	li	%r3,0
	bl	_C_LABEL(lcsplx)
	stw	%r3,PCB_SPL(%r31)	/* save spl */

/* Find a new process */
	mfmsr	%r3
	andi.	%r3,%r3,~PSL_EE@l	/* disable interrupts while
					   manipulating runque */
	mtmsr	%r3
	isync

	lis	%r8,_C_LABEL(whichqs)@ha
	lwz	%r9,_C_LABEL(whichqs)@l(%r8)

	or.	%r9,%r9,%r9
	beq-	_C_LABEL(idle)		/* all queues empty */
_C_LABEL(sw1):
	cntlzw	%r10,%r9
	lis	%r4,_C_LABEL(qs)@ha
	addi	%r4,%r4,_C_LABEL(qs)@l
	slwi	%r3,%r10,3
	add	%r3,%r3,%r4		/* select queue */

	lwz	%r31,P_FORW(%r3)	/* unlink first proc from queue */
	lwz	%r4,P_FORW(%r31)
	stw	%r4,P_FORW(%r3)
	stw	%r3,P_BACK(%r4)

	cmpl	0,%r3,%r4			/* queue empty? */
	bne	1f

	lis	%r3,0x80000000@ha
	srw	%r3,%r3,%r10
	andc	%r9,%r9,%r3
	stw	%r9,_C_LABEL(whichqs)@l(%r8)	/* mark it empty */

1:
	/* just did this resched thing, clear resched */
	li	%r3,0
	lis	%r4,_C_LABEL(want_resched)@ha
	stw	%r3,_C_LABEL(want_resched)@l(%r4)

	stw	%r3,P_BACK(%r31)		/* probably superfluous */

	lis	%r4,_C_LABEL(curproc)@ha
	stw	%r31,_C_LABEL(curproc)@l(%r4)	/* record new process */

	li	%r3,SONPROC
	stb	%r3,P_STAT(%r31)

	mfmsr	%r3
	ori	%r3,%r3,PSL_EE		/* Now we can interrupt again */
	mtmsr	%r3

	cmpl	0,%r31,%r30		/* is it the same process? */
	beq	switch_return

	or.	%r30,%r30,%r30		/* old process was exiting? */
	beq	switch_exited

	mfsr	%r10,PPC_USER_SR	/* save PPC_USER_SR for copyin/copyout*/
	mfcr	%r11			/* save cr */
	mr	%r12,%r2		/* save r2 */
	stwu	%r1,-SFRAMELEN(%r1)	/* still running on old stack */
	stmw	%r10,8(%r1)
	lwz	%r3,P_ADDR(%r30)
	stw	%r1,PCB_SP(%r3)		/* save SP */

switch_exited:
	/* disable interrupts while actually switching */
	mfmsr	%r3
	andi.	%r3,%r3,~PSL_EE@l
	mtmsr	%r3

	lwz	%r4,P_ADDR(%r31)
	lis	%r5,_C_LABEL(curpcb)@ha
	stw	%r4,_C_LABEL(curpcb)@l(%r5)	/* indicate new pcb */

	lwz	%r5,PCB_PMR(%r4)

	/* save real pmap pointer for spill fill */
	lis	%r6,_C_LABEL(curpm)@ha
	stwu	%r5,_C_LABEL(curpm)@l(%r6)
	stwcx.	%r5,%r0,%r6		/* clear possible reservation */

	addic.	%r5,%r5,64
	li	%r6,0
	mfsr	%r8,PPC_KERNEL_SR	/* save kernel SR */
1:
	addis	%r6,%r6,-0x10000000@ha	/* set new procs segment registers */
	or.	%r6,%r6,%r6		/* This is done from the real address pmap */
	lwzu	%r7,-4(%r5)		/* so we don't have to worry */
	mtsrin	%r7,%r6			/* about accessibility */
	bne	1b
	mtsr	PPC_KERNEL_SR,%r8	/* restore kernel SR */
	isync

	lwz	%r1,PCB_SP(%r4)		/* get new procs SP */

	ori	%r3,%r3,PSL_EE		/* interrupts are okay again */
	mtmsr	%r3

	lmw	%r10,8(%r1)		/* get other regs */
	lwz	%r1,0(%r1)		/* get saved SP */
	mr	%r2,%r12		/* get saved r2 */
	mtcr	%r11			/* get saved cr */
	isync
	mtsr	PPC_USER_SR,%r10	/* get saved PPC_USER_SR */
	isync

switch_return:
	mr	%r30,%r7		/* save proc pointer */
	lwz	%r3,PCB_SPL(%r4)
	bl	_C_LABEL(lcsplx)

	mr	%r3,%r30		/* curproc for special fork returns */

	lwz	%r31,12(%r1)
	lwz	%r30,8(%r1)
	addi	%r1,%r1,16
	lwz	%r0,4(%r1)
	mtlr	%r0
	blr


/*
 * Data used during primary/secondary traps/interrupts
 */
#define	tempsave	0x2e0		/* primary save area for trap handling */
#define	disisave	0x3e0		/* primary save area for dsi/isi traps */
#define	INTSTK	(8*1024)		/* 8K interrupt stack */
	.data
intstk:	.space	INTSTK			/* interrupt stack */
	.global _C_LABEL(intr_depth)
	.type  _C_LABEL(intr_depth),@object
_C_LABEL(intr_depth):
	.long	-1			/* in-use marker */
#define	SPILLSTK 1024			/* 1K spill stack */
.lcomm	spillstk,SPILLSTK,8

/*
 * This code gets copied to all the trap vectors
 * except ISI/DSI, ALI, and the interrupts
 */
	.text
	.globl	_C_LABEL(trapcode),_C_LABEL(trapsize)
	.type	_C_LABEL(trapcode),@function
	.type	_C_LABEL(trapsize),@object
_C_LABEL(trapcode):
	mtsprg	1,%r1			/* save SP */
	stmw	%r28,tempsave(%r0)	/* free r28-r31 */
	mflr	%r28			/* save LR */
	mfcr	%r29			/* save CR */

	/* Test whether we already had PR set */
	mfsrr1	%r31
	mtcr	%r31
	bc	4,17,1f			/* branch if PSL_PR is clear */
	lis	%r1,_C_LABEL(curpcb)@ha
	lwz	%r1,_C_LABEL(curpcb)@l(%r1)
	addi	%r1,%r1,USPACE		/* stack is top of user struct */
1:
	bla	s_trap
_C_LABEL(trapsize) =	.-_C_LABEL(trapcode)

/*
 * For ALI: has to save DSISR and DAR
 */
	.globl	_C_LABEL(alitrap),_C_LABEL(alisize)
_C_LABEL(alitrap):
	mtsprg	1,%r1			/* save SP */
	stmw	%r28,tempsave(0)	/* free r28-r31 */
	mfdar	%r30
	mfdsisr	%r31
	stmw	%r30,tempsave+16(0)
	mflr	%r28			/* save LR */
	mfcr	%r29			/* save CR */

	/* Test whether we already had PR set */
	mfsrr1	%r31
	mtcr	%r31
	bc	4,17,1f			/* branch if PSL_PR is clear */
	lis	%r1,_C_LABEL(curpcb)@ha
	lwz	%r1,_C_LABEL(curpcb)@l(%r1)
	addi	%r1,%r1,USPACE		/* stack is top of user struct */
1:
	bla	s_trap
_C_LABEL(alisize) =	.-_C_LABEL(alitrap)

/*
 * Similar to the above for DSI
 * Has to handle BAT spills
 * and standard pagetable spills
 */
	.globl	_C_LABEL(dsitrap),_C_LABEL(dsisize)
	.type	_C_LABEL(dsitrap),@function
	.type	_C_LABEL(dsisize),@object
_C_LABEL(dsitrap):
	stmw	%r28,disisave(0)	/* free r28-r31 */
	mfcr	%r29			/* save CR */
	mfxer	%r30			/* save XER */
	mtsprg	2,%r30			/* in SPRG2 */
	mfsrr1	%r31			/* test kernel mode */
#if 0
	mtcr	%r31
	bc	12,17,1f		/* branch if PSL_PR is set */
	mfdar	%r31			/* get fault address */
	rlwinm	%r31,%r31,7,25,28	/* get segment * 8 */
	addis	%r31,%r31,_C_LABEL(battable)@ha
	lwz	%r30,_C_LABEL(battable)@l(%r31)	/* get batu */
	mtcr	%r30
	bc	4,30,1f			/* branch if supervisor valid is false */
	lwz	%r31,_C_LABEL(battable)+4@l(%r31)	/* get batl */
/* We randomly use the highest two bat registers here */
	mftb	%r28
	andi.	%r28,%r28,1
	bne	2f
	mtdbatu	2,%r30
	mtdbatl	2,%r31
	b	3f
2:
	mtdbatu	3,%r30
	mtdbatl	3,%r31
3:
	mfsprg	%r30,2			/* restore XER */
	mtxer	%r30
	mtcr	%r29			/* restore CR */
	lmw	%r28,disisave(0)	/* restore r28-r31 */
	rfi				/* return to trapped code */
1:
#endif
	mflr	%r28			/* save LR */
	bla	s_dsitrap
_C_LABEL(dsisize) =	.-_C_LABEL(dsitrap)

/*
 * Similar to the above for ISI
 */
	.globl	_C_LABEL(isitrap),_C_LABEL(isisize)
	.type	_C_LABEL(isitrap),@function
	.type	_C_LABEL(isisize),@object
_C_LABEL(isitrap):
	stmw	%r28,disisave(0)	/* free r28-r31 */
	mflr	%r28			/* save LR */
	mfcr	%r29			/* save CR */
	mfsrr1	%r31			/* test kernel mode */
#if 0
	mtcr	%r31
	bc	12,17,1f		/* branch if PSL_PR is set */
	mfsrr0	%r31			/* get fault address */
	rlwinm	%r31,%r31,7,25,28		/* get segment * 8 */
	addis	%r31,%r31,_C_LABEL(battable)@ha
	lwz	%r30,_C_LABEL(battable)@l(%r31)	/* get batu */
	mtcr	%r30
	bc	4,30,1f			/* branch if supervisor valid is false */
	mtibatu	3,%r30
	lwz	%r30,_C_LABEL(battable)+4@l(%r31)	/* get batl */
	mtibatl	3,%r30
	mtcr	%r29			/* restore CR */
	lmw	%r28,disisave(0)	/* restore r28-r31 */
	rfi				/* return to trapped code */
1:
#endif
	bla	s_isitrap
_C_LABEL(isisize) =	.-_C_LABEL(isitrap)

/*
 * This one for the external interrupt handler.
 */
	.globl	_C_LABEL(extint),_C_LABEL(extsize)
	.type	_C_LABEL(extint),@function
	.type	_C_LABEL(extsize),@object
_C_LABEL(extint):
	mtsprg	1,%r1			/* save SP */
	stmw	%r28,tempsave(0)	/* free r28-r31 */
	mflr	%r28			/* save LR */
	mfcr	%r29			/* save CR */
	mfxer	%r30			/* save XER */
	lis	%r1,intstk+INTSTK@ha	/* get interrupt stack */
	addi	%r1,%r1,intstk+INTSTK@l
	lwz	%r31,0(%r1)		/* were we already running on intstk? */
	addic.	%r31,%r31,%r1
	stw	%r31,0(%r1)
	beq	1f
	mfsprg	%r1,1			/* yes, get old SP */
1:
	ba	extintr
_C_LABEL(extsize) =	.-_C_LABEL(extint)

/*
 * And this one for the decrementer interrupt handler.
 */
	.globl	_C_LABEL(decrint),_C_LABEL(decrsize)
	.type	_C_LABEL(decrint),@function
	.type	_C_LABEL(decrsize),@object
_C_LABEL(decrint):
	mtsprg	1,%r1			/* save SP */
	stmw	%r28,tempsave(0)	/* free r28-r31 */
	mflr	%r28			/* save LR */
	mfcr	%r29			/* save CR */
	mfxer	%r30			/* save XER */
	lis	%r1,intstk+INTSTK@ha	/* get interrupt stack */
	addi	%r1,%r1,intstk+INTSTK@l
	lwz	%r31,0(%r1)		/* were we already running on intstk? */
	addic.	%r31,%r31,%r1
	stw	%r31,0(%r1)
	beq	1f
	mfsprg	%r1,1			/* yes, get old SP */
1:
	ba	decrintr
_C_LABEL(decrsize) =	.-_C_LABEL(decrint)

/*
 * Now the tlb software load for 603 processors:
 * (Code essentially from the 603e User Manual, Chapter 5)
 */
#define	DMISS	976
#define	DCMP	977
#define	HASH1	978
#define	HASH2	979
#define	IMISS	980
#define	ICMP	981
#define	RPA	982

#define	bdneq	bdnzf 2,
#define	tlbli	.long	0x7c0007e4+0x800*
#define	tlbld	.long	0x7c0007a4+0x800*

	.globl	_C_LABEL(tlbimiss),_C_LABEL(tlbimsize)
	.type	_C_LABEL(tlbimiss),@function
	.type	_C_LABEL(tlbimsize),@object
_C_LABEL(tlbimiss):
	mfspr	%r2,HASH1		/* get first pointer */
	li	%r1,8
	mfctr	%r0			/* save counter */
	mfspr	%r3,ICMP		/* get first compare value */
	addi	%r2,%r2,-8		/* predec pointer */
1:
	mtctr	%r1			/* load counter */
2:
	lwzu	%r1,8(%r2)		/* get next pte */
	cmpl	0,%r1,%r3		/* see if found pte */
	bdneq	2b			/* loop if not eq */
	bne	3f			/* not found */
	lwz	%r1,4(%r2)		/* load tlb entry lower word */
	andi.	%r3,%r1,8		/* check G-bit */
	bne	4f			/* if guarded, take ISI */
	mtctr	%r0			/* restore counter */
	mfspr	%r0,IMISS		/* get the miss address for the tlbli */
	mfsrr1	%r3			/* get the saved cr0 bits */
	mtcrf	0x80,%r3		/* and restore */
	ori	%r1,%r1,0x100		/* set the reference bit */
	mtspr	RPA,%r1			/* set the pte */
	srwi	%r1,%r1,8		/* get byte 7 of pte */
	tlbli	0			/* load the itlb */
	stb	%r1,6(%r2)		/* update page table */
	rfi

3:	/* not found in pteg */
	andi.	%r1,%r3,0x40		/* have we already done second hash? */
	bne	5f
	mfspr	%r2,HASH2		/* get the second pointer */
	ori	%r3,%r3,0x40		/* change the compare value */
	li	%r1,8
	addi	%r2,%r2,-8		/* predec pointer */
	b	1b
4:	/* guarded */
	mfsrr1	%r3
	andi.	%r2,%r3,0xffff		/* clean upper srr1 */
	addis	%r2,%r2,0x800		/* set srr<4> to flag prot violation */
	b	6f
5:	/* not found anywhere */
	mfsrr1	%r3
	andi.	%r2,%r3,0xffff		/* clean upper srr1 */
	addis	%r2,%r2,0x4000		/* set srr1<1> to flag pte not found */
6:
	mtctr	%r0			/* restore counter */
	mtsrr1	%r2
	mfmsr	%r0
	xoris	%r0,%r0,2		/* flip the msr<tgpr> bit */
	mtcrf	0x80,%r3		/* restore cr0 */
	mtmsr	%r0			/* now with native gprs */
	isync
	ba	EXC_ISI
_C_LABEL(tlbimsize) =	.-_C_LABEL(tlbimiss)

	.globl	_C_LABEL(tlbdlmiss),_C_LABEL(tlbdlmsize)
	.type	_C_LABEL(tlbdlmiss),@function
	.type	_C_LABEL(tlbdlmsize),@object
_C_LABEL(tlbdlmiss):
	mfspr	%r2,HASH1		/* get first pointer */
	li	%r1,8
	mfctr	%r0			/* save counter */
	mfspr	%r3,DCMP		/* get first compare value */
	addi	%r2,%r2,-8		/* predec pointer */
1:
	mtctr	%r1			/* load counter */
2:
	lwzu	%r1,8(%r2)		/* get next pte */
	cmpl	0,%r1,%r3		/* see if found pte */
	bdneq	2b			/* loop if not eq */
	bne	3f			/* not found */
	lwz	%r1,4(%r2)		/* load tlb entry lower word */
	mtctr	%r0			/* restore counter */
	mfspr	%r0,DMISS		/* get the miss address for the tlbld */
	mfsrr1	%r3			/* get the saved cr0 bits */
	mtcrf	0x80,%r3		/* and restore */
	ori	%r1,%r1,0x100		/* set the reference bit */
	mtspr	RPA,%r1			/* set the pte */
	srwi	%r1,%r1,8		/* get byte 7 of pte */
	tlbld	0			/* load the dtlb */
	stb	%r1,6(%r2)		/* update page table */
	rfi

3:	/* not found in pteg */
	andi.	%r1,%r3,0x40		/* have we already done second hash? */
	bne	5f
	mfspr	%r2,HASH2		/* get the second pointer */
	ori	%r3,%r3,0x40		/* change the compare value */
	li	%r1,8
	addi	%r2,%r2,-8		/* predec pointer */
	b	1b
5:	/* not found anywhere */
	mfsrr1	%r3
	lis	%r1,0x4000		/* set dsisr<1> to flag pte not found */
	mtctr	%r0			/* restore counter */
	andi.	%r2,%r3,0xffff		/* clean upper srr1 */
	mtsrr1	%r2
	mtdsisr	%r1			/* load the dsisr */
	mfspr	%r1,DMISS		/* get the miss address */
	mtdar	%r1			/* put in dar */
	mfmsr	%r0
	xoris	%r0,%r0,2		/* flip the msr<tgpr> bit */
	mtcrf	0x80,%r3		/* restore cr0 */
	mtmsr	%r0			/* now with native gprs */
	isync
	ba	EXC_DSI
_C_LABEL(tlbdlmsize) =	.-_C_LABEL(tlbdlmiss)

	.globl	_C_LABEL(tlbdsmiss),_C_LABEL(tlbdsmsize)
	.type	_C_LABEL(tlbdsmiss),@function
	.type	_C_LABEL(tlbdsmsize),@object
_C_LABEL(tlbdsmiss):
	mfspr	%r2,HASH1		/* get first pointer */
	li	%r1,8
	mfctr	%r0			/* save counter */
	mfspr	%r3,DCMP		/* get first compare value */
	addi	%r2,%r2,-8		/* predec pointer */
1:
	mtctr	%r1			/* load counter */
2:
	lwzu	%r1,8(%r2)		/* get next pte */
	cmpl	0,%r1,%r3		/* see if found pte */
	bdneq	2b			/* loop if not eq */
	bne	3f			/* not found */
	lwz	%r1,4(%r2)		/* load tlb entry lower word */
	andi.	%r3,%r1,0x80		/* check the C-bit */
	beq	4f
5:
	mtctr	%r0			/* restore counter */
	mfspr	%r0,DMISS		/* get the miss address for the tlbld */
	mfsrr1	%r3			/* get the saved cr0 bits */
	mtcrf	0x80,%r3		/* and restore */
	mtspr	RPA,%r1			/* set the pte */
	tlbld	0			/* load the dtlb */
	rfi

3:	/* not found in pteg */
	andi.	%r1,%r3,0x40		/* have we already done second hash? */
	bne	5f
	mfspr	%r2,HASH2		/* get the second pointer */
	ori	%r3,%r3,0x40		/* change the compare value */
	li	%r1,8
	addi	%r2,%r2,-8		/* predec pointer */
	b	1b
4:	/* found, but C-bit = 0 */
	rlwinm.	%r3,%r1,30,0,1		/* test PP */
	bge-	7f
	andi.	%r3,%r1,1
	beq+	8f
9:	/* found, but protection violation (PP==00)*/
	mfsrr1	%r3
	lis	%r1,0xa00	/* indicate protection violation on store */
	b	1f
7:	/* found, PP=1x */
	mfspr	%r3,DMISS		/* get the miss address */
	mfsrin	%r1,%r3			/* get the segment register */
	mfsrr1	%r3
	rlwinm	%r3,%r3,18,31,31	/* get PR-bit */
	rlwnm.	%r2,%r2,3,1,1		/* get the key */
	bne-	9b			/* protection violation */
8:	/* found, set reference/change bits */
	lwz	%r1,4(%r2)		/* reload tlb entry */
	ori	%r1,%r1,0x180
	sth	%r1,6(%r2)
	b	5b
5:	/* not found anywhere */
	mfsrr1	%r3
	lis	%r1,0x4200		/* set dsisr<1> to flag pte not found */
					/* dsisr<6> to flag store */
1:
	mtctr	%r0			/* restore counter */
	andi.	%r2,%r3,0xffff		/* clean upper srr1 */
	mtsrr1	%r2
	mtdsisr	%r1			/* load the dsisr */
	mfspr	%r1,DMISS		/* get the miss address */
	mtdar	%r1			/* put in dar */
	mfmsr	%r0
	xoris	%r0,%r0,2		/* flip the msr<tgpr> bit */
	mtcrf	0x80,%r3		/* restore cr0 */
	mtmsr	%r0			/* now with native gprs */
	isync
	ba	EXC_DSI
_C_LABEL(tlbdsmsize) =	.-_C_LABEL(tlbdsmiss)

#ifdef DDB
#define ddbsave	0xde0		/* primary save area for DDB */
/*
 * In case of DDB we want a separate trap catcher for it
 */
	.local	ddbstk
	.comm	ddbstk,INTSTK,8	/* ddb stack */

	.globl	_C_LABEL(ddblow),_C_LABEL(ddbsize)
_C_LABEL(ddblow):
	mtsprg	1,%r1			/* save SP */
	stmw	%r28,ddbsave(0)		/* free r28-r31 */
	mflr	%r28			/* save LR */
	mfcr	%r29			/* save CR */
	lis	%r1,ddbstk+INTSTK@ha	/* get new SP */
	addi	%r1,%r1,ddbstk+INTSTK@l
	bla	ddbtrap
_C_LABEL(ddbsize) =	.-_C_LABEL(ddblow)
#endif  /* DDB */


/*
 * FRAME_SETUP assumes:
 *	SPRG1		SP (1)
 *	savearea	r28-r31,DAR,DSISR	(DAR & DSISR only for DSI traps)
 *	28		LR
 *	29		CR
 *	1		kernel stack
 *	LR		trap type
 *	SRR0/1		as at start of trap
 */
#define	FRAME_SETUP(savearea)						\
/* Have to enable translation to allow access of kernel stack: */	\
	mfsrr0	%r30;							\
	mfsrr1	%r31;							\
	stmw	%r30,savearea+24(0);					\
	mfmsr	%r30;							\
	ori	%r30,%r30,(PSL_DR|PSL_IR);				\
	mtmsr	%r30;							\
	isync;								\
	mfsprg	%r31,1;							\
	stwu	%r31,-FRAMELEN(%r1);					\
	stw	%r0,FRAME_0+8(%r1);					\
	stw	%r31,FRAME_1+8(%r1);					\
	stw	%r28,FRAME_LR+8(%r1);					\
	stw	%r29,FRAME_CR+8(%r1);					\
	lmw	%r28,savearea(0);					\
	stmw	%r2,FRAME_2+8(%r1);					\
	lmw	%r28,savearea+16(0);					\
	mfxer	%r3;							\
	mfctr	%r4;							\
	mflr	%r5;							\
	andi.	%r5,%r5,0xff00;						\
	stw	%r3,FRAME_XER+8(%r1);					\
	stw	%r4,FRAME_CTR+8(%r1);					\
	stw	%r5,FRAME_EXC+8(%r1);					\
	stw	%r28,FRAME_DAR+8(%r1);					\
	stw	%r29,FRAME_DSISR+8(%r1);				\
	stw	%r30,FRAME_SRR0+8(%r1);					\
	stw	%r31,FRAME_SRR1+8(%r1)

#define	FRAME_LEAVE(savearea)						\
/* Now restore regs: */							\
	lwz	%r2,FRAME_SRR0+8(%r1);					\
	lwz	%r3,FRAME_SRR1+8(%r1);					\
	lwz	%r4,FRAME_CTR+8(%r1);					\
	lwz	%r5,FRAME_XER+8(%r1);					\
	lwz	%r6,FRAME_LR+8(%r1);					\
	lwz	%r7,FRAME_CR+8(%r1);					\
	stw	%r2,savearea(0);					\
	stw	%r3,savearea+4(0);					\
	mtctr	%r4;							\
	mtxer	%r5;							\
	mtlr	%r6;							\
	mtsprg	1,%r7;			/* save cr */			\
	lmw	%r2,FRAME_2+8(%r1);					\
	lwz	%r0,FRAME_0+8(%r1);					\
	lwz	%r1,FRAME_1+8(%r1);					\
	mtsprg	2,%r2;			/* save r2 & r3 */		\
	mtsprg	3,%r3;							\
/* Disable translation, machine check and recoverability: */		\
	mfmsr	%r2;							\
	lis	%r3,(PSL_DR|PSL_IR|PSL_ME|PSL_RI)@ha;			\
	addi	%r3,%r3,(PSL_DR|PSL_IR|PSL_ME|PSL_RI)@l;		\
	andc	%r2,%r2,%r3;						\
	mtmsr	%r2;							\
	isync;								\
/* Decide whether we return to user mode: */				\
	lwz	%r3,savearea+4(0);					\
	mtcr	%r3;							\
	bc	4,17,1f;		/* branch if PSL_PR is false */	\
/* Restore user & kernel access SR: */					\
	lis	%r2,_C_LABEL(curpm)@ha;	/* get real address of pmap */	\
	lwz	%r2,_C_LABEL(curpm)@l(%r2);				\
	lwz	%r3,PM_USRSR(%r2);					\
	mtsr	PPC_USER_SR,%r3;					\
	lwz	%r3,PM_KERNELSR(%r2);					\
	mtsr	PPC_KERNEL_SR,%r3;					\
1:	mfsprg	%r2,1;			/* restore cr */		\
	mtcr	%r2;							\
	lwz	%r2,savearea(0);					\
	lwz	%r3,savearea+4(0);					\
	mtsrr0	%r2;							\
	mtsrr1	%r3;							\
	mfsprg	%r2,2;			/* restore r2 & r3 */		\
	mfsprg	%r3,3

/*
 * Preamble code for DSI/ISI traps
 */
disitrap:
	lmw	%r30,disisave(0)
	stmw	%r30,tempsave(0)
	lmw	%r30,disisave+8(0)
	stmw	%r30,tempsave+8(0)
	mfdar	%r30
	mfdsisr	%r31
	stmw	%r30,tempsave+16(0)
realtrap:
	/* Test whether we already had PR set */
	mfsrr1	%r1
	mtcr	%r1
	/* restore SP (might have been overwritten) */
	mfsprg	%r1,1
	bc	4,17,s_trap		/* branch if PSL_PR is false */
	lis	%r1,_C_LABEL(curpcb)@ha
	lwz	%r1,_C_LABEL(curpcb)@l(%r1)
	addi	%r1,%r1,USPACE		/* stack is top of user struct */
/*
 * Now the common trap catching code.
 */
s_trap:
/* First have to enable KERNEL mapping */
	lis	%r31,PPC_KERNEL_SEGMENT@ha
	addi	%r31,%r31,PPC_KERNEL_SEGMENT@l
	mtsr	PPC_KERNEL_SR,%r31
	FRAME_SETUP(tempsave)
/* Now we can recover interrupts again: */
	mfmsr	%r7
	mfsrr1	%r31
	andi.	%r31,%r31,PSL_EE	/* restore EE from previous context */
	or	%r7,%r7,%r31
	ori	%r7,%r7,(PSL_ME|PSL_RI)
	mtmsr	%r7
	isync
/* Call C trap code: */
trapagain:
	addi	%r3,%r1,8
	bl	_C_LABEL(trap)
trapexit:
/* Disable interrupts: */
	mfmsr	%r3
	andi.	%r3,%r3,~PSL_EE@l
	mtmsr	%r3
/* Test AST pending: */
	lwz	%r5,FRAME_SRR1+8(%r1)
	mtcr	%r5
	bc	4,17,1f			/* branch if PSL_PR is false */
	lis	%r3,_C_LABEL(astpending)@ha
	lwz	%r4,_C_LABEL(astpending)@l(%r3)
	andi.	%r4,%r4,1
	beq	1f
	li	%r6,EXC_AST
	stw	%r6,FRAME_EXC+8(%r1)
	b	trapagain
1:
	FRAME_LEAVE(tempsave)
	rfi

/*
 * Child comes here at the end of a fork.
 * Mostly similar to the above.
 */
	.globl	_C_LABEL(fork_trampoline)
	.type	_C_LABEL(fork_trampoline),@function
_C_LABEL(fork_trampoline):
	li	%r3,0
	bl	_C_LABEL(lcsplx)
	mtlr	%r31
	mr	%r3,%r30
	blrl				/* jump indirect to r31 */
	b	trapexit

/*
 * DSI second stage fault handler
 */
s_dsitrap:
	mfdsisr	%r31			/* test if this is spill fault */
	mtcr	%r31
	mtsprg	1,%r1			/* save SP */
	bc	4,1,disitrap		/* branch if table miss is false */
	lis	%r1,spillstk+SPILLSTK@ha
	addi	%r1,%r1,spillstk+SPILLSTK@l	/* get spill stack */
	stwu	%r1,-52(%r1)
	stw	%r0,48(%r1)		/* save non-volatile registers */
	stw	%r3,44(%r1)
	stw	%r4,40(%r1)
	stw	%r5,36(%r1)
	stw	%r6,32(%r1)
	stw	%r7,28(%r1)
	stw	%r8,24(%r1)
	stw	%r9,20(%r1)
	stw	%r10,16(%r1)
	stw	%r11,12(%r1)
	stw	%r12,8(%r1)
	mfxer	%r30			/* save XER */
	mtsprg	2,%r30
	mflr	%r30			/* save trap type */
	mfctr	%r31			/* & CTR */
	mfdar	%r3
	mfsrr1	%r4
	mfdsisr	%r5
	li	%r6, 0
s_pte_spill:
	bl	_C_LABEL(pte_spill_r)	/* try a spill */
	cmpwi	0,%r3,0
	mtctr	%r31			/* restore CTR */
	mtlr	%r30			/* and trap type */
	mfsprg	%r31,2			/* get saved XER */
	mtxer	%r31			/* restore XER */
	lwz	%r12,8(%r1)		/* restore non-volatile registers */
	lwz	%r11,12(%r1)
	lwz	%r10,16(%r1)
	lwz	%r9,20(%r1)
	lwz	%r8,24(%r1)
	lwz	%r7,28(%r1)
	lwz	%r6,32(%r1)
	lwz	%r5,36(%r1)
	lwz	%r4,40(%r1)
	lwz	%r3,44(%r1)
	lwz	%r0,48(%r1)
	beq	disitrap
	mfsprg	%r1,1			/* restore SP */
	mtcr	%r29			/* restore CR */
	mtlr	%r28			/* restore LR */
	lmw	%r28,disisave(0)	/* restore r28-r31 */
	rfi				/* return to trapped code */

/*
 * ISI second stage fault handler
 */
s_isitrap:
	mfsrr1	%r31			/* test if this may be a spill fault */
	mtcr	%r31
	mtsprg	1,%r1			/* save SP */
	bc	4,%r1,disitrap		/* branch if table miss is false */
	lis	%r1,spillstk+SPILLSTK@ha
	addi	%r1,%r1,spillstk+SPILLSTK@l	/* get spill stack */
	stwu	%r1,-52(%r1)
	stw	%r0,48(%r1)		/* save non-volatile registers */
	stw	%r3,44(%r1)
	stw	%r4,40(%r1)
	stw	%r5,36(%r1)
	stw	%r6,32(%r1)
	stw	%r7,28(%r1)
	stw	%r8,24(%r1)
	stw	%r9,20(%r1)
	stw	%r10,16(%r1)
	stw	%r11,12(%r1)
	stw	%r12,8(%r1)
	mfxer	%r30			/* save XER */
	mtsprg	2,%r30
	mflr	%r30			/* save trap type */
	mfctr	%r31			/* & ctr */
	mfsrr0	%r3
	mfsrr1	%r4
	li	%r5, 0
	li	%r6, 1
	b	s_pte_spill		/* above */

/*
 * External interrupt second level handler
 */
#define	INTRENTER							\
/* Save non-volatile registers: */					\
	stwu	%r1,-88(%r1);		/* temporarily */		\
	stw	%r0,84(%r1);						\
	mfsprg	%r0,1;			/* get original SP */		\
	stw	%r0,0(%r1);		/* and store it */		\
	stw	%r3,80(%r1);						\
	stw	%r4,76(%r1);						\
	stw	%r5,72(%r1);						\
	stw	%r6,68(%r1);						\
	stw	%r7,64(%r1);						\
	stw	%r8,60(%r1);						\
	stw	%r9,56(%r1);						\
	stw	%r10,52(%r1);						\
	stw	%r11,48(%r1);						\
	stw	%r12,44(%r1);						\
	stw	%r28,40(%r1);		/* saved LR */			\
	stw	%r29,36(%r1);		/* saved CR */			\
	stw	%r30,32(%r1);		/* saved XER */			\
	lmw	%r28,tempsave(0);	/* restore r28-r31 */		\
	mfctr	%r6;							\
	lis	%r5,_C_LABEL(intr_depth)@ha;				\
	lwz	%r5,_C_LABEL(intr_depth)@l(%r5);			\
	mfsrr0	%r4;							\
	mfsrr1	%r3;							\
	stw	%r6,28(%r1);						\
	stw	%r5,20(%r1);						\
	stw	%r4,12(%r1);						\
	stw	%r3,8(%r1);						\
/* interrupts are recoverable here, and enable translation */		\
	lis	%r3,(PPC_KERNEL_SEGMENT|SR_SUKEY|SR_PRKEY)@ha;		\
	addi	%r3,%r3,(PPC_KERNEL_SEGMENT|SR_SUKEY|SR_PRKEY)@l;	\
	mtsr	PPC_KERNEL_SR,%r3;					\
	mfmsr	%r5;							\
	ori	%r5,%r5,(PSL_IR|PSL_DR|PSL_RI);				\
	mtmsr	%r5;							\
	isync

	.globl	_C_LABEL(extint_call)
	.type	_C_LABEL(extint_call),@function
extintr:
	INTRENTER
_C_LABEL(extint_call):
	bl	_C_LABEL(extint_call)		/* to be filled in later */
intr_exit:
/* Disable interrupts (should already be disabled) and MMU here: */
	mfmsr	%r3
	andi.	%r3,%r3,~(PSL_EE|PSL_ME|PSL_RI|PSL_DR|PSL_IR)@l
	mtmsr	%r3
	isync
/* restore possibly overwritten registers: */
	lwz	%r12,44(%r1)
	lwz	%r11,48(%r1)
	lwz	%r10,52(%r1)
	lwz	%r9,56(%r1)
	lwz	%r8,60(%r1)
	lwz	%r7,64(%r1)
	lwz	%r6,8(%r1)
	lwz	%r5,12(%r1)
	lwz	%r4,28(%r1)
	lwz	%r3,32(%r1)
	mtsrr1	%r6
	mtsrr0	%r5
	mtctr	%r4
	mtxer	%r3
/* Returning to user mode? */
	mtcr	%r6			/* saved SRR1 */
	bc	4,17,1f			/* branch if PSL_PR is false */
	lis	%r3,_C_LABEL(curpm)@ha	/* get current pmap real address */
	lwz	%r3,_C_LABEL(curpm)@l(%r3)
	lwz	%r3,PM_KERNELSR(%r3)
	mtsr	PPC_KERNEL_SR,%r3		/* Restore kernel SR */
	lis	%r3,_C_LABEL(astpending)@ha	/* Test AST pending */
	lwz	%r4,_C_LABEL(astpending)@l(%r3)
	andi.	%r4,%r4,1
	beq	1f
/* Setup for entry to realtrap: */
	lwz	%r3,0(%r1)		/* get saved SP */
	mtsprg	%r1,3
	li	%r6,EXC_AST
	stmw	%r28,tempsave(0)	/* establish tempsave again */
	mtlr	%r6
	lwz	%r28,40(%r1)		/* saved LR */
	lwz	%r29,36(%r1)		/* saved CR */
	lwz	%r6,68(%r1)
	lwz	%r5,72(%r1)
	lwz	%r4,76(%r1)
	lwz	%r3,80(%r1)
	lwz	%r0,84(%r1)
	lis	%r30,_C_LABEL(intr_depth)@ha	/* adjust reentrancy count */
	lwz	%r31,_C_LABEL(intr_depth)@l(%r30)
	addi	%r31,%r31,-1
	stw	%r31,_C_LABEL(intr_depth)@l(%r30)
	b	realtrap
1:
/* Here is the normal exit of extintr: */
	lwz	%r5,36(%r1)
	lwz	%r6,40(%r1)
	mtcr	%r5
	mtlr	%r6
	lwz	%r6,68(%r1)
	lwz	%r5,72(%r1)
	lis	%r3,_C_LABEL(intr_depth)@ha	/* adjust reentrancy count */
	lwz	%r4,_C_LABEL(intr_depth)@l(%r3)
	addi	%r4,%r4,-1
	stw	%r4,_C_LABEL(intr_depth)@l(%r3)
	lwz	%r4,76(%r1)
	lwz	%r3,80(%r1)
	lwz	%r0,84(%r1)
	lwz	%r1,0(%r1)
	rfi

/*
 * Decrementer interrupt second level handler
 */
decrintr:
	INTRENTER
	addi	%r3,%r1,8			/* intr frame */
	bl	_C_LABEL(decr_intr)
	b	intr_exit


/*
 * int setfault()
 *
 * Similar to setjmp to setup for handling faults on accesses to user memory.
 * Any routine using this may only call bcopy, either the form below,
 * or the (currently used) C code optimized, so it doesn't use any non-volatile
 * registers.
 */
	.globl	_C_LABEL(setfault)
	.type	_C_LABEL(setfault),@function
_C_LABEL(setfault):
	mflr	%r0
	mfcr	%r12
	mfmsr	%r2
	lis	%r4,_C_LABEL(curpcb)@ha
	lwz	%r4,_C_LABEL(curpcb)@l(%r4)
	stw	%r3,PCB_FAULT(%r4)
	stw	%r0,0(%r3)
	stw	%r2,4(%r3)
	stw	%r1,8(%r3)
	stmw	%r12,12(%r3)
	li	%r3,0
	blr

/*
 * The following code gets copied to the top of the user stack on process
 * execution.  It does signal trampolining on signal delivery.
 *
 * On entry r1 points to a struct sigframe at bottom of current stack.
 * All other registers are unchanged.
 */
	.globl	_C_LABEL(sigcode),_C_LABEL(esigcode)
	.type	_C_LABEL(sigcode),@function
	.type	_C_LABEL(esigcode),@function
_C_LABEL(sigcode):
	addi	%r1,%r1,-((16+FPSIG_SIZEOF+15)& ~0xf)		/* reserved space for callee */
	addi	%r6,%r1,8
	stfd	%f0,0(%r6)
	stfd	%f1,8(%r6)
	stfd	%f2,16(%r6)
	stfd	%f3,24(%r6)
	stfd	%f4,32(%r6)
	stfd	%f5,40(%r6)
	stfd	%f6,48(%r6)
	stfd	%f7,56(%r6)
	stfd	%f8,64(%r6)
	stfd	%f9,72(%r6)
	stfd	%f10,80(%r6)
	stfd	%f11,88(%r6)
	stfd	%f12,96(%r6)
	stfd	%f13,104(%r6)
	mffs	%f0
	stfd	%f0,112(%r6)
	lfd	%f0,0(%r6)	/* restore the clobbered register */
		
	blrl
	addi	%r6,%r1,8
	lfd	%f0,112(%r6)
	mtfsf	0xff,%f0
	lfd	%f0,0(%r6)
	lfd	%f1,8(%r6)
	lfd	%f2,16(%r6)
	lfd	%f3,24(%r6)
	lfd	%f4,32(%r6)
	lfd	%f5,40(%r6)
	lfd	%f6,48(%r6)
	lfd	%f7,56(%r6)
	lfd	%f8,64(%r6)
	lfd	%f9,72(%r6)
	lfd	%f10,80(%r6)
	lfd	%f11,88(%r6)
	lfd	%f12,96(%r6)
	lfd	%f13,104(%r6)
	addi	%r3,%r1,((16+FPSIG_SIZEOF+15)&~0xf)+SF_SC	/* compute &sf_sc */
	li	%r0,SYS_sigreturn
	sc				/* sigreturn(scp) */
	li	%r0,SYS_exit
	sc				/* exit(errno) */
_C_LABEL(esigcode):


#ifdef DDB
/*
 * Deliberate entry to ddbtrap
 */
	.globl	_C_LABEL(ddb_trap)
_C_LABEL(ddb_trap):
	mtsprg	%r1,1
	mfmsr	%r3
	mtsrr1	%r3
	andi.	%r3,%r3,~(PSL_EE|PSL_ME)@l
	mtmsr	%r3				/* disable interrupts */
	isync
	stmw	%r28,ddbsave(0)
	mflr	%r28
	li	%r29,EXC_BPT
	mtlr	%r29
	mfcr	%r29
	mtsrr0	%r28

/*
 * Now the ddb trap catching code.
 */
ddbtrap:
	FRAME_SETUP(ddbsave)
/* Call C trap code: */
	addi	%r3,%r1,8
	bl	_C_LABEL(ddb_trap_glue)
	or.	%r3,%r3,%r3
	bne	ddbleave
/* This wasn't for DDB, so switch to real trap: */
	lwz	%r3,FRAME_EXC+8(%r1)	/* save exception */
	stw	%r3,ddbsave+8(0)
	FRAME_LEAVE(ddbsave)
	mtsprg	%r1,1			/* prepare for entrance to realtrap */
	stmw	%r28,tempsave(0)
	mflr	%r28
	mfcr	%r29
	lwz	%r31,ddbsave+8(0)
	mtlr	%r31
	b	realtrap
ddbleave:
	FRAME_LEAVE(ddbsave)
	rfi
#endif /* DDB */