xref: /netbsd/sys/arch/powerpc/ibm4xx/trap_subr.S (revision 6550d01e)
1/*	$NetBSD: trap_subr.S,v 1.13 2011/01/18 01:02:54 matt Exp $	*/
2
3/*
4 * Copyright 2001 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Eduardo Horvath and Simon Burge for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 *    must display the following acknowledgement:
19 *      This product includes software developed for the NetBSD Project by
20 *      Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 *    or promote products derived from this software without specific prior
23 *    written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38/*
39 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
40 * Copyright (C) 1995, 1996 TooLs GmbH.
41 * All rights reserved.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 *    notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 *    notice, this list of conditions and the following disclaimer in the
50 *    documentation and/or other materials provided with the distribution.
51 * 3. All advertising materials mentioning features or use of this software
52 *    must display the following acknowledgement:
53 *	This product includes software developed by TooLs GmbH.
54 * 4. The name of TooLs GmbH may not be used to endorse or promote products
55 *    derived from this software without specific prior written permission.
56 *
57 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
58 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
59 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
60 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
61 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
62 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
63 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
64 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
65 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
66 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
67 */
68
69/*
70 * NOTICE: This is not a standalone file.  to use it, #include it in
71 * your port's locore.S, like so:
72 *
73 *	#include <powerpc/ibm4xx/trap_subr.S>
74 */
75
76/*
77 * XXX Interrupt and spill stacks need to be per-CPU.
78 */
79
80#define	GET_PCB(rX)	\
81	GET_CPUINFO(rX);	\
82	lwz	rX,CI_CURPCB(rX)
83
84#define	STANDARD_PROLOG(savearea)	\
85	mtsprg1	%r1;			/* save SP */ 		\
86	GET_CPUINFO(%r1);					\
87	stmw	%r28,(savearea+CPUSAVE_R28)(%r1); /* free r28-r31 */	\
88	mflr	%r28;			/* save LR */		\
89	mfcr	%r29;			/* save CR */		\
90	mfsrr0	%r30;						\
91	mfsrr1	%r31; /* Test whether we already had PR set */	\
92	stmw	%r30,(savearea+CPUSAVE_SRR0)(%r1); /* save srr0/srr1 */	\
93	mtcr	%r31;						\
94	bc	%cr4,MSR_PR,1f;	/* branch if MSR[PR] is clear */	\
95	lwz	%r1,CI_CURPCB(%r1);				\
96	addi	%r1,%r1,USPACE-CALLFRAMELEN; /* stack is top of user struct */ \
971:
98
99#define	ACCESS_PROLOG(savearea)					\
100	mtsprg1	%r1;			/* save SP */ 		\
101	GET_CPUINFO(%r1);					\
102	stmw	%r28,(savearea+CPUSAVE_R28)(%r1); /* free r28-r31 */	\
103	mflr	%r28;			/* save LR */		\
104	mfcr	%r29;			/* save CR */		\
105	mfdear	%r30;						\
106	mfesr	%r31;						\
107	stmw	%r30,(savearea+CPUSAVE_DEAR)(%r1);		\
108	mfsrr0	%r30;						\
109	mfsrr1	%r31; /* Test whether we already had PR set */	\
110	stmw	%r30,(savearea+CPUSAVE_SRR0)(%r1); /* save srr0/srr1 */	\
111	mtcr	%r31;						\
112	bc	%cr4,MSR_PR,1f;	/* branch if MSR[PR] is clear */	\
113	lwz	%r1,CI_CURPCB(%r1);				\
114	addi	%r1,%r1,USPACE-CALLFRAMELEN; /* stack is top of user struct */ \
1151:
116
117#define	CRITICAL_PROLOG(savearea)				\
118	mtsprg1	%r1;			/* save SP */ 		\
119	GET_CPUINFO(%r2);					\
120	stmw	%r28,(savearea+CPUSAVE_R28)(%r1); /* free r28-r31 */	\
121	mflr	%r28;			/* save LR */		\
122	mfcr	%r29;			/* save CR */		\
123	mfsrr2	%r30; /* Fake a standard trap */		\
124	mfsrr3	%r31; /* Test whether we already had PR set */	\
125	stmw	%r30,(savearea+CPUSAVE_SRR0)(%r1); /* save srr0/srr1 */	\
126	mtcr	%r31;						\
127	bc	%cr4,MSR_PR,1f;	/* branch if MSR[PR] is clear */	\
128	lwz	%r1,CI_CURPCB(%r1);				\
129	addi	%r1,%r1,USPACE-CALLFRAMELEN; /* stack is top of user struct */ \
1301:
131
132
133/* Standard handler saves r1,r28-31,LR,CR, sets up the stack and calls s_trap */
134#define STANDARD_EXC_HANDLER(name)\
135	.globl	_C_LABEL(name ## trap),_C_LABEL(name ## size) ;	\
136_C_LABEL(name ## trap):						\
137	STANDARD_PROLOG(CI_TEMPSAVE);				\
138	bla	s_trap  ;					\
139_C_LABEL(name ## size) = .-_C_LABEL(name ## trap)
140
141/* Access exceptions also need DEAR and ESR saved */
142#define ACCESS_EXC_HANDLER(name)\
143	.globl	_C_LABEL(name ## trap),_C_LABEL(name ## size) ;	\
144_C_LABEL(name ## trap):						\
145	ACCESS_PROLOG(CI_TEMPSAVE);				\
146	bla	s_trap  ;					\
147_C_LABEL(name ## size) = .-_C_LABEL(name ## trap)
148
149/* Maybe this should call ddb.... */
150#define CRITICAL_EXC_HANDLER(name)\
151	.globl	_C_LABEL(name ## trap),_C_LABEL(name ## size) ;	\
152_C_LABEL(name ## trap):						\
153	CRITICAL_PROLOG(CI_TEMPSAVE);				\
154	bla	s_trap  ;					\
155_C_LABEL(name ## size) = .-_C_LABEL(name ## trap)
156
157#define	INTR_PROLOG(tempsave)					\
158	mtsprg1	%r1;			/* save SP */		\
159	GET_CPUINFO(%r1);					\
160	stmw	%r28,(tempsave+CPUSAVE_R28)(%r1); /* free r28-r31 */ \
161	mflr	%r28;			/* save LR */		\
162	mfcr	%r29;			/* save CR */		\
163	mfxer	%r30;			/* save XER */		\
164	lwz	%r31,CI_IDEPTH(%r1);	/* already running on intstk? */ \
165	addic.	%r31,%r31,1;					\
166	stw	%r31,CI_IDEPTH(%r1);				\
167	lwz	%r1,CI_INTSTK(%r1);	/* get intstk */	\
168	beq	1f;						\
169	mfsprg1	%r1;			/* yes, get old SP */	\
1701:
171
172/*
173 * This code gets copied to all the trap vectors
174 * (except ISI/DSI, ALI, the interrupts, and possibly the debugging
175 * traps when using IPKDB).
176 */
177	.text
178	STANDARD_EXC_HANDLER(default)
179	ACCESS_EXC_HANDLER(ali)
180	ACCESS_EXC_HANDLER(dsi)
181	ACCESS_EXC_HANDLER(isi)
182	STANDARD_EXC_HANDLER(debug)
183	CRITICAL_EXC_HANDLER(mchk)
184
185/*
186 * This one for the external interrupt handler.
187 */
188	.globl	_C_LABEL(extint),_C_LABEL(extsize)
189_C_LABEL(extint):
190	INTR_PROLOG(CI_TEMPSAVE)
191	ba	extintr
192_C_LABEL(extsize) = .-_C_LABEL(extint)
193
194
195#if defined(DDB) || defined(KGDB)
196/*
197 * In case of DDB we want a separate trap catcher for it
198 */
199	.lcomm	ddbstk,INTSTK,16	/* ddb stack */
200
201	.globl	_C_LABEL(ddblow),_C_LABEL(ddbsize)
202_C_LABEL(ddblow):
203	mtsprg1	%r1			/* save SP */
204	GET_CPUINFO(%r1)
205	stmw	%r28,CI_DDBSAVE(%r1)	/* free r28-r31 */
206	mflr	%r28			/* save LR */
207	mfcr	%r29			/* save CR */
208	lis	%r1,ddbstk+INTSTK-CALLFRAMELEN@ha	/* get new SP */
209	addi	%r1,%r1,ddbstk+INTSTK-CALLFRAMELEN@l
210	bla	ddbtrap
211_C_LABEL(ddbsize) = .-_C_LABEL(ddblow)
212#endif	/* DDB || KGDB */
213
214#ifdef IPKDB
215/*
216 * In case of IPKDB we want a separate trap catcher for it
217 */
218
219	.lcomm	ipkdbstk,INTSTK,16	/* ipkdb stack */
220
221	.globl	_C_LABEL(ipkdblow),_C_LABEL(ipkdbsize)
222_C_LABEL(ipkdblow):
223	mtsprg1	%r1			/* save SP */
224	GET_CPUINFO(%r1)
225	stmw	%r28,CI_IPKDBSAVE(%r1)	/* free r28-r31 */
226	mflr	%r28			/* save LR */
227	mfcr	%r29			/* save CR */
228	lis	%r1,ipkdbstk+INTSTK-CALLFRAMELEN@ha	/* get new SP */
229	addi	%r1,%r1,ipkdbstk+INTSTK-CALLFRAMELEN@l
230	bla	ipkdbtrap
231_C_LABEL(ipkdbsize) = .-_C_LABEL(ipkdblow)
232#endif	/* IPKDB */
233
234#ifdef DEBUG
235#define TRAP_IF_ZERO(r)	tweqi	r,0
236#else
237#define TRAP_IF_ZERO(r)
238#endif
239
240#define	ENABLE_TRANSLATION(pidreg,tmpreg)				\
241	mfpid	pidreg;							\
242	li	tmpreg, KERNEL_PID;					\
243	mtpid	tmpreg;							\
244	mfmsr	tmpreg;							\
245	ori	tmpreg,tmpreg,(PSL_DR|PSL_IR)@l;			\
246	mtmsr	tmpreg;							\
247	isync
248
249/*
250 * FRAME_SETUP assumes:
251 *	SPRG1		SP (r1)
252 *	savearea	r28-r31,DEAR,ESR,SRR0,SRR1 (DEAR & ESR only for DSI traps)
253 *	%r28		LR
254 *	%r29		CR
255 *	%r1		kernel stack
256 *	LR		trap type
257 */
258#define	FRAME_SETUP(savearea)						\
259/* Have to enable translation to allow access of kernel stack: */	\
260	ENABLE_TRANSLATION(%r30,%r31);					\
261	mfsprg1	%r31;							\
262	stwu	%r31,-FRAMELEN(%r1);					\
263	stw	%r30,FRAME_PID(%r1);					\
264	stw	%r0,FRAME_R0(%r1);					\
265	stw	%r31,FRAME_R1(%r1);					\
266	stw	%r2,FRAME_R2(%r1);					\
267	GET_CPUINFO(%r2);						\
268	stw	%r28,FRAME_LR(%r1);					\
269	stw	%r29,FRAME_CR(%r1);					\
270	lmw	%r28,(savearea+CPUSAVE_R28)(%r2);			\
271	stmw	%r3,FRAME_R3(%r1);					\
272	lmw	%r28,(savearea+CPUSAVE_DEAR)(%r2);			\
273	mfxer	%r3;							\
274	mfctr	%r4;							\
275	mflr	%r5;							\
276	andi.	%r5,%r5,0xff00;						\
277	stw	%r3,FRAME_XER(%r1);					\
278	stw	%r4,FRAME_CTR(%r1);					\
279	stw	%r5,FRAME_EXC(%r1);					\
280	stw	%r28,FRAME_DEAR(%r1);					\
281	stw	%r29,FRAME_ESR(%r1);					\
282	stw	%r30,FRAME_SRR0(%r1);					\
283	stw	%r31,FRAME_SRR1(%r1)
284
285#define	FRAME_SAVE_CALLEE						\
286	stmw	%r13, FRAME_R13(%r1)
287
288#define	FRAME_RESTORE							\
289	lwz	%r6,FRAME_LR(%r1);					\
290	lwz	%r7,FRAME_CR(%r1);					\
291	lwz	%r8,FRAME_XER(%r1);					\
292	lwz	%r9,FRAME_CTR(%r1);					\
293	lwz	%r10,FRAME_SRR0(%r1);					\
294	lwz	%r11,FRAME_SRR1(%r1);					\
295	mtlr	%r6;							\
296	mtcr	%r7;							\
297	mtxer	%r8;							\
298	mtctr	%r9;							\
299	mtsrr0	%r10;							\
300	mtsrr1	%r11;							\
301	lwz	%r12,FRAME_R12(%r1);					\
302	lwz	%r11,FRAME_R11(%r1);					\
303	lwz	%r10,FRAME_R10(%r1);					\
304	lwz	%r9,FRAME_R9(%r1);					\
305	lwz	%r8,FRAME_R8(%r1);					\
306	lwz	%r7,FRAME_R7(%r1);					\
307	lwz	%r6,FRAME_R6(%r1);					\
308	lwz	%r5,FRAME_R5(%r1);					\
309	lwz	%r4,FRAME_R4(%r1);					\
310	lwz	%r3,FRAME_R3(%r1);					\
311	lwz	%r2,FRAME_R2(%r1);					\
312	lwz	%r0,FRAME_R1(%r1);					\
313	mtsprg1	%r0;							\
314	lwz	%r0,FRAME_R0(%r1)
315
316/*
317 * Now the common trap catching code.
318 */
319s_trap:
320	FRAME_SETUP(CI_TEMPSAVE)
321	/* R31 = SRR1 */
322/* Now we can recover interrupts again: */
323trapagain:
324	wrtee	%r31			/* reenable interrupts */
325/* Call C trap code: */
326	addi	%r3,%r1,FRAME_TF
327	bl	_C_LABEL(trap)
328	.globl	_C_LABEL(trapexit)
329_C_LABEL(trapexit):
330	/* Disable interrupts: */
331	wrteei	0
332
333	/* Test AST pending: */
334	mtcr	%r31
335	bc	%cr4,MSR_PR,trapleave_to_kernel /* branch if MSR[PR] is false */
336
337	GET_CPUINFO(%r3)
338	lwz	%r4,CI_ASTPENDING(%r3)
339	andi.	%r4,%r4,1
340	beq	trapleave_to_user
341
342	li	%r6,EXC_AST
343	stw	%r6,FRAME_EXC(%r1)
344	b	trapagain
345
346trapleave_to_kernel:
347	lmw	%r13, FRAME_R13(%r1)	/* restore callee registers */
348
349intrleave_to_kernel:
350	FRAME_RESTORE		/* old SP is now in sprg1 */
351	/*
352	 * Now that we are done with the trapframe, we can load the original SP
353	 */
354	mfsprg1	%r1
355	rfi
356	ba	.		/* Protect against prefetch */
357
358trapleave_to_user:
359	lmw	%r13, FRAME_R13(%r1)	/* restore callee registers */
360
361intrleave_to_user:
362/* Now restore regs: */
363	lwz	%r3,FRAME_PID(%r1)
364	lwz	%r4,FRAME_SRR1(%r1)
365	bl	_C_LABEL(ctx_setup)
366	TRAP_IF_ZERO(%r3)
367	stw	%r3,FRAME_PID(%r1)
368
369	FRAME_RESTORE		/* old SP is now in sprg1 */
370
371	/*
372	 * We are returning to userspace so we need to switch PIDs.
373	 * Since the kernel executes out of what would be userspace,
374	 * we need to turn off translation before we set the PID.
375	 *
376	 * Alterantively, we could map a kernel page at 0xfffff000
377	 * that had the mtpid code in it and branch to it and avoid
378	 * all this.  (ba foo; foo: mtpid %r31; mfsprg3 %r31; rfi;)
379	 */
380	mfmsr	%r30
381	li	%r31,(PSL_DR|PSL_IR)@l
382	andc	%r30,%r30,%r31
383	lwz	%r31,FRAME_PID(%r1)
384	TRAP_IF_ZERO(%r31)
385	/*
386	 * Now that we are done with the trapframe, we can load the original SP
387	 */
388	mfsprg1	%r1
389	mtmsr	%r30	/* disable translation */
390	isync
391	mtpid	%r31
392	mfsprg3	%r31
393	mfsprg2	%r30
394	rfi
395	ba	.	/* Protect against prefetch */
396
397
398	.globl	_C_LABEL(sctrap),_C_LABEL(scsize),_C_LABEL(sctrapexit)
399_C_LABEL(sctrap):
400	STANDARD_PROLOG(CI_TEMPSAVE)
401	bla	s_sctrap
402_C_LABEL(scsize) = .-_C_LABEL(sctrap)
403
404s_sctrap:
405	FRAME_SETUP(CI_TEMPSAVE)
406/* Now we can recover interrupts again: */
407	wrteei	1			/* Enable interrupts */
408/* Call the appropriate syscall handler: */
409	addi	%r3,%r1,FRAME_TF
410	GET_CPUINFO(%r4)
411	lwz	%r4,CI_CURLWP(%r4)
412	lwz	%r4,L_PROC(%r4)
413	lwz	%r4,P_MD_SYSCALL(%r4)
414	mtctr	%r4
415	bctrl
416_C_LABEL(sctrapexit):
417	b	trapexit
418
419/*
420 * External interrupt second level handler
421 */
422
423#define	INTR_SAVE(tempsave)						\
424/* Save non-volatile registers: */					\
425	stwu	%r1,-FRAMELEN(%r1);	/* temporarily */		\
426	stw	%r0,FRAME_R0(%r1);					\
427	mfsprg1	%r0;			/* get original SP */		\
428	stw	%r0,FRAME_R1(%r1);	/* and store it */		\
429	stw	%r2,FRAME_R2(%r1);					\
430	stw	%r3,FRAME_R3(%r1);					\
431	stw	%r4,FRAME_R4(%r1);					\
432	stw	%r5,FRAME_R5(%r1);					\
433	stw	%r6,FRAME_R6(%r1);					\
434	stw	%r7,FRAME_R7(%r1);					\
435	stw	%r8,FRAME_R8(%r1);					\
436	stw	%r9,FRAME_R9(%r1);					\
437	stw	%r10,FRAME_R10(%r1);					\
438	stw	%r11,FRAME_R11(%r1);					\
439	stw	%r12,FRAME_R12(%r1);					\
440	mfctr	%r31;							\
441	stmw	%r28,FRAME_LR(%r1);	/* save LR, CR, XER, CTR */	\
442	GET_CPUINFO(%r5);						\
443	lmw	%r28,(tempsave+CPUSAVE_R28)(%r5); /* restore r28-r31 */	\
444	lwz	%r5,CI_IDEPTH(%r5);					\
445	mfsrr0	%r4;							\
446	mfsrr1	%r3;							\
447	stw	%r5,FRAME_IDEPTH(%r1);					\
448	stw	%r4,FRAME_SRR0(%r1);					\
449	stw	%r3,FRAME_SRR1(%r1);					\
450/* interrupts are recoverable here, and enable translation */		\
451	ENABLE_TRANSLATION(%r0,%r5);					\
452	stw	%r0,FRAME_PID(%r1);					\
453
454	.globl	_C_LABEL(extint_call)
455extintr:
456	INTR_SAVE(CI_TEMPSAVE)
457_C_LABEL(extint_call):
458	bl	_C_LABEL(extint_call)	/* to be filled in later */
459
460intr_exit:
461/* Disable interrupts */
462	wrteei	0
463	isync
464	GET_CPUINFO(%r5)
465	lwz	%r4,CI_IDEPTH(%r5)
466	addi	%r4,%r4,-1		/* adjust reentrancy count */
467	stw	%r4,CI_IDEPTH(%r5)
468
469	lwz	%r5,FRAME_SRR1(%r1)
470/* Returning to user mode? */
471	mtcr	%r5			/* saved SRR1 */
472	bc	%cr4,MSR_PR,intrleave_to_kernel /* branch if MSR[PR] is false */
473
474	lwz	%r4,CI_ASTPENDING(%r5)	/* Test AST pending */
475	andi.	%r4,%r4,1
476	beq	intrleave_to_user
477
478	FRAME_SAVE_CALLEE		/* save rest of callee registers */
479	li	%r6,EXC_AST
480	stw	%r6,FRAME_EXC(%r1)
481	mr	%r31,%r5		/* move SRR1 to R31 */
482	b	trapagain
483
484/*
485 * PIT interrupt handler.
486 */
487	.align	5
488_C_LABEL(pitint):
489	INTR_PROLOG(CI_TEMPSAVE)
490	INTR_SAVE(CI_TEMPSAVE)
491	addi	%r3,%r1,FRAME_CF	/* intr frame */
492	bl	_C_LABEL(decr_intr)
493	b	intr_exit
494
495/*
496 * FIT interrupt handler.
497 */
498	.align	5
499_C_LABEL(fitint):
500	INTR_PROLOG(CI_TEMPSAVE)
501	INTR_SAVE(CI_TEMPSAVE)
502	addi	%r3,%r1,FRAME_TF	/* intr frame */
503	bl	_C_LABEL(stat_intr)
504	b	intr_exit
505
506#if defined(DDB) || defined(KGDB)
507/*
508 * Deliberate entry to ddbtrap
509 */
510	.globl	_C_LABEL(ddb_trap)
511_C_LABEL(ddb_trap):
512	mtsprg1	%r1
513	GET_CPUINFO(%r4)
514	mfmsr	%r3
515	stw	%r3,CI_DDBSAVE+CPUSAVE_SRR1(%r4)
516	wrteei	0			/* disable interrupts */
517	isync
518	stmw	%r28,CI_DDBSAVE(%r1)
519	mflr	%r28
520	stw	%r28,CI_DDBSAVE+CPUSAVE_SRR0(%r4)
521	li	%r29,EXC_BPT
522	mtlr	%r29
523	mfcr	%r29
524
525/*
526 * Now the ddb/kgdb trap catching code.
527 */
528ddbtrap:
529	FRAME_SETUP(CI_DDBSAVE)
530/* Call C trap code: */
531	addi	%r3,%r1,FRAME_TF
532	bl	_C_LABEL(ddb_trap_glue)
533	or.	%r3,%r3,%r3
534	addi	%r3,%r1,FRAME_TF
535	beq	trapagain
536	b	trapexit
537#endif /* DDB || KGDB */
538
539#ifdef IPKDB
540/*
541 * Deliberate entry to ipkdbtrap
542 */
543	.globl	_C_LABEL(ipkdb_trap)
544_C_LABEL(ipkdb_trap):
545	mtsprg1	%r1
546	GET_CPUINFO(%r4)
547	mfmsr	%r3
548	stw	%r3,(CI_IPKDBSAVE+CPUSAVE_SRR1)(%r4)
549	wrteei	0			/* disable interrupts */
550	isync
551	stmw	%r28,CI_IPKDBSAVE(%r4)
552	mflr	%r28
553	stw	%r28,(CI_IPKDBSAVE+CPUSAVE_SRR0)(%r4)
554	li	%r29,EXC_BPT
555	mtlr	%r29
556	mfcr	%r29
557
558/*
559 * Now the ipkdb trap catching code.
560 */
561ipkdbtrap:
562	FRAME_SETUP(CI_IPKDBSAVE)
563/* Call C trap code: */
564	addi	%r3,%r1,FRAME_TF
565	bl	_C_LABEL(ipkdb_trap_glue)
566	or.	%r3,%r3,%r3
567	beq	trapagain
568	b	trapexit
569
570ipkdbfault:
571	ba	_ipkdbfault
572_ipkdbfault:
573	mfsrr0	%r3
574	addi	%r3,%r3,4
575	mtsrr0	%r3
576	li	%r3,-1
577	rfi
578	ba	.	/* Protect against prefetch */
579
580/*
581 * int ipkdbfbyte(unsigned char *p)
582 */
583	.globl	_C_LABEL(ipkdbfbyte)
584_C_LABEL(ipkdbfbyte):
585	li	%r9,EXC_DSI		/* establish new fault routine */
586	lwz	%r5,0(%r9)
587	lis	%r6,ipkdbfault@ha
588	lwz	%r6,ipkdbfault@l(%r6)
589	stw	%r6,0(%r9)
590#ifdef	IPKDBUSERHACK
591#ifndef PPC_IBM4XX
592	lis	%r8,_C_LABEL(ipkdbsr)@ha
593	lwz	%r8,_C_LABEL(ipkdbsr)@l(%r8)
594	mtsr	USER_SR,%r8
595	isync
596#endif
597#endif
598	dcbst	%r0,%r9			/* flush data... */
599	sync
600	icbi	%r0,%r9			/* and instruction caches */
601	lbz	%r3,0(%r3)		/* fetch data */
602	stw	%r5,0(%r9)		/* restore previous fault handler */
603	dcbst	%r0,%r9			/* and flush data... */
604	sync
605	icbi	%r0,%r9			/* and instruction caches */
606	blr
607
608/*
609 * int ipkdbsbyte(unsigned char *p, int c)
610 */
611	.globl	_C_LABEL(ipkdbsbyte)
612_C_LABEL(ipkdbsbyte):
613	li	%r9,EXC_DSI		/* establish new fault routine */
614	lwz	%r5,0(%r9)
615	lis	%r6,ipkdbfault@ha
616	lwz	%r6,ipkdbfault@l(%r6)
617	stw	%r6,0(%r9)
618#ifdef	IPKDBUSERHACK
619#ifndef PPC_IBM4XX
620	lis	%r8,_C_LABEL(ipkdbsr)@ha
621	lwz	%r8,_C_LABEL(ipkdbsr)@l(%r8)
622	mtsr	USER_SR,%r8
623	isync
624#endif
625#endif
626	dcbst	%r0,%r9			/* flush data... */
627	sync
628	icbi	%r0,%r9			/* and instruction caches */
629	mr	%r6,%r3
630	xor	%r3,%r3,%r3
631	stb	%r4,0(%r6)
632	dcbst	%r0,%r6			/* Now do appropriate flushes
633					   to data... */
634	sync
635	icbi	%r0,%r6			/* and instruction caches */
636	stw	%r5,0(%r9)		/* restore previous fault handler */
637	dcbst	%r0,%r9			/* and flush data... */
638	sync
639	icbi	%r0,%r9			/* and instruction caches */
640	blr
641#endif	/* IPKDB */
642