xref: /netbsd-src/sys/arch/powerpc/ibm4xx/trap_subr.S (revision c38e7cc395b1472a774ff828e46123de44c628e9)
1/*	$NetBSD: trap_subr.S,v 1.26 2016/12/28 09:36:02 rin 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	mfsprg1	%r1;			/* restore SP */ 	\
94	mtcr	%r31;						\
95	bf	MSR_PR,1f;		/* branch if MSR[PR] is clear */ \
96	GET_PCB(%r1);						\
97	addi	%r1,%r1,USPACE-CALLFRAMELEN; /* stack is top of user struct */ \
981:
99
100#define	ACCESS_PROLOG(savearea)					\
101	mtsprg1	%r1;			/* save SP temporalily */ \
102	GET_CPUINFO(%r1);					\
103	stmw	%r28,(savearea+CPUSAVE_R28)(%r1); /* free r28-r31 */ \
104	mflr	%r28;			/* save LR */		\
105	mfcr	%r29;			/* save CR */		\
106	mfdear	%r30;						\
107	mfesr	%r31;						\
108	stmw	%r30,(savearea+CPUSAVE_DEAR)(%r1); /* save esr/dear */ \
109	mfsrr0	%r30;						\
110	mfsrr1	%r31; /* Test whether we already had PR set */	\
111	stmw	%r30,(savearea+CPUSAVE_SRR0)(%r1); /* save srr0/srr1 */	\
112	mfsprg1	%r1;			/* restore SP */ 	\
113	mtcr	%r31;						\
114	bf	MSR_PR,1f;		/* branch if MSR[PR] is clear */ \
115	GET_PCB(%r1);						\
116	addi	%r1,%r1,USPACE-CALLFRAMELEN; /* stack is top of user struct */ \
1171:
118
119#define	CRITICAL_PROLOG(savearea)				\
120	mtsprg1	%r1;			/* save SP */ 		\
121	GET_CPUINFO(%r1);					\
122	stmw	%r28,(savearea+CPUSAVE_R28)(%r1); /* free r28-r31 */ \
123	mflr	%r28;			/* save LR */		\
124	mfcr	%r29;			/* save CR */		\
125	mfsrr2	%r30; /* Fake a standard trap */		\
126	mfsrr3	%r31; /* Test whether we already had PR set */	\
127	stmw	%r30,(savearea+CPUSAVE_SRR0)(%r1); /* save srr0/srr1 */	\
128	mfsprg1	%r1;			/* restore SP */ 	\
129	mtcr	%r31;						\
130	bf	MSR_PR,1f;		/* branch if MSR[PR] is clear */ \
131	GET_PCB(%r1);						\
132	addi	%r1,%r1,USPACE-CALLFRAMELEN; /* stack is top of user struct */ \
1331:
134
135
136/* Standard handler saves r1,r28-31,LR,CR, sets up the stack and calls s_trap */
137#define STANDARD_EXC_HANDLER(name)\
138	.globl	_C_LABEL(name ## trap),_C_LABEL(name ## size) ;	\
139_C_LABEL(name ## trap):						\
140	STANDARD_PROLOG(CI_TEMPSAVE);				\
141	bla	s_trap;						\
142_C_LABEL(name ## size) = .-_C_LABEL(name ## trap)
143
144/* Access exceptions also need DEAR and ESR saved */
145#define ACCESS_EXC_HANDLER(name)\
146	.globl	_C_LABEL(name ## trap),_C_LABEL(name ## size) ;	\
147_C_LABEL(name ## trap):						\
148	ACCESS_PROLOG(CI_TEMPSAVE);				\
149	bla	s_trap;						\
150_C_LABEL(name ## size) = .-_C_LABEL(name ## trap)
151
152/* Maybe this should call ddb.... */
153#define CRITICAL_EXC_HANDLER(name)\
154	.globl	_C_LABEL(name ## trap),_C_LABEL(name ## size) ;	\
155_C_LABEL(name ## trap):						\
156	CRITICAL_PROLOG(CI_TEMPSAVE);				\
157	bla	s_trap;						\
158_C_LABEL(name ## size) = .-_C_LABEL(name ## trap)
159
160#define	INTR_PROLOG(tempsave)					\
161	mtsprg1	%r1;			/* save SP */		\
162	GET_CPUINFO(%r1);					\
163	stmw	%r28,(tempsave+CPUSAVE_R28)(%r1); /* free r28-r31 */ \
164	mflr	%r28;			/* save LR */		\
165	mfcr	%r29;			/* save CR */		\
166	mfxer	%r30;			/* save XER */		\
167	mfsrr1	%r31;						\
168	mtcr	%r31;						\
169	mfsprg1	%r1;			/* restore SP */ 	\
170	bf	MSR_PR,1f;		/* branch if PSL_PR is false */ \
171	GET_PCB(%r1);						\
172	addi	%r1,%r1,USPACE-CALLFRAMELEN; /* stack is top of user struct */ \
1731:
174
175	.text
176	STANDARD_EXC_HANDLER(default)
177	ACCESS_EXC_HANDLER(access)
178	CRITICAL_EXC_HANDLER(critical)
179
180/*
181 * This one for the external interrupt handler.
182 */
183	.globl	_C_LABEL(extint),_C_LABEL(extsize)
184_C_LABEL(extint):
185	INTR_PROLOG(CI_TEMPSAVE)
186	ba	extintr
187_C_LABEL(extsize) = .-_C_LABEL(extint)
188
189
190#if defined(DDB) || defined(KGDB)
191/*
192 * In case of DDB we want a separate trap catcher for it
193 */
194	.globl	_C_LABEL(ddblow),_C_LABEL(ddbsize)
195_C_LABEL(ddblow):
196	ACCESS_PROLOG(CI_DDBSAVE)
197	bla	ddbtrap
198_C_LABEL(ddbsize) = .-_C_LABEL(ddblow)
199#endif	/* DDB || KGDB */
200
201#ifdef IPKDB
202/*
203 * In case of IPKDB we want a separate trap catcher for it
204 */
205	.globl	_C_LABEL(ipkdblow),_C_LABEL(ipkdbsize)
206_C_LABEL(ipkdblow):
207	ACCESS_PROLOG(CI_IPKDBSAVE)
208	bla	ipkdbtrap
209_C_LABEL(ipkdbsize) = .-_C_LABEL(ipkdblow)
210#endif	/* IPKDB */
211
212#ifdef DEBUG
213#define TRAP_IF_ZERO(r)	tweqi	r,0
214#else
215#define TRAP_IF_ZERO(r)
216#endif
217
218#define	ENABLE_TRANSLATION(pidreg,tmpreg)				\
219	mfpid	pidreg;							\
220	li	tmpreg,KERNEL_PID;					\
221	mtpid	tmpreg;							\
222	mfmsr	tmpreg;							\
223	ori	tmpreg,tmpreg,(PSL_DR|PSL_IR)@l;			\
224	mtmsr	tmpreg;							\
225	isync
226
227/*
228 * FRAME_SETUP assumes:
229 *	SPRG1		SP (r1)
230 *	savearea	r28-r31,DEAR,ESR,SRR0,SRR1
231 *			(DEAR & ESR only for access traps)
232 *	%r28		LR
233 *	%r29		CR
234 *	%r1		kernel stack
235 *	LR		trap type
236 */
237#define	FRAME_SETUP(savearea)						\
238/* Have to enable translation to allow access of kernel stack: */	\
239	ENABLE_TRANSLATION(%r30,%r31);					\
240	mfsprg1	%r31;							\
241	stwu	%r31,-FRAMELEN(%r1);					\
242	stw	%r30,FRAME_PID(%r1);					\
243	stw	%r0,FRAME_R0(%r1);					\
244	stw	%r31,FRAME_R1(%r1);					\
245	stw	%r2,FRAME_R2(%r1);					\
246	GET_CPUINFO(%r2);						\
247	stw	%r28,FRAME_LR(%r1);					\
248	stw	%r29,FRAME_CR(%r1);					\
249	lmw	%r28,(savearea+CPUSAVE_R28)(%r2);			\
250	stmw	%r3,FRAME_R3(%r1);					\
251	lmw	%r28,(savearea+CPUSAVE_DEAR)(%r2);			\
252	lwz	%r13,CI_CURLWP(%r2);					\
253	mfxer	%r3;							\
254	mfctr	%r4;							\
255	mflr	%r5;							\
256	andi.	%r5,%r5,0xff00;						\
257	stw	%r3,FRAME_XER(%r1);					\
258	stw	%r4,FRAME_CTR(%r1);					\
259	stw	%r5,FRAME_EXC(%r1);					\
260	stw	%r28,FRAME_DEAR(%r1);					\
261	stw	%r29,FRAME_ESR(%r1);					\
262	stw	%r30,FRAME_SRR0(%r1);					\
263	stw	%r31,FRAME_SRR1(%r1)
264
265#define	FRAME_SAVE_CALLEE						\
266	stmw	%r14,FRAME_R14(%r1)
267
268#define	FRAME_RESTORE							\
269	lwz	%r6,FRAME_LR(%r1);					\
270	lwz	%r7,FRAME_CR(%r1);					\
271	lwz	%r8,FRAME_XER(%r1);					\
272	lwz	%r9,FRAME_CTR(%r1);					\
273	lwz	%r10,FRAME_SRR0(%r1);					\
274	lwz	%r11,FRAME_SRR1(%r1);					\
275	mtlr	%r6;							\
276	mtcr	%r7;							\
277	mtxer	%r8;							\
278	mtctr	%r9;							\
279	mtsrr0	%r10;							\
280	mtsrr1	%r11;							\
281	lwz	%r13,FRAME_R13(%r1);					\
282	lwz	%r12,FRAME_R12(%r1);					\
283	lwz	%r11,FRAME_R11(%r1);					\
284	lwz	%r10,FRAME_R10(%r1);					\
285	lwz	%r9,FRAME_R9(%r1);					\
286	lwz	%r8,FRAME_R8(%r1);					\
287	lwz	%r7,FRAME_R7(%r1);					\
288	lwz	%r6,FRAME_R6(%r1);					\
289	lwz	%r5,FRAME_R5(%r1);					\
290	lwz	%r4,FRAME_R4(%r1);					\
291	lwz	%r3,FRAME_R3(%r1);					\
292	lwz	%r2,FRAME_R2(%r1);					\
293	lwz	%r0,FRAME_R1(%r1);					\
294	mtsprg1	%r0;							\
295	lwz	%r0,FRAME_R0(%r1)
296
297/*
298 * Now the common trap catching code.
299 */
300s_trap:
301	FRAME_SETUP(CI_TEMPSAVE)
302	/* R31 = SRR1 */
303/* Now we can recover interrupts again: */
304trapagain:
305	wrtee	%r31			/* reenable interrupts */
306/* Call C trap code: */
307	addi	%r3,%r1,FRAME_TF
308	bl	_C_LABEL(trap)
309	.globl	_C_LABEL(trapexit)
310_C_LABEL(trapexit):
311	/* Disable interrupts: */
312	wrteei	0
313
314	/* Test AST pending: */
315	mtcr	%r31
316	bf	MSR_PR,trapleave_to_kernel /* branch if MSR[PR] is false */
317
318	lwz	%r4,L_MD_ASTPENDING(%r13)
319	andi.	%r4,%r4,1
320	beq	trapleave_to_user
321
322	li	%r6,EXC_AST
323	stw	%r6,FRAME_EXC(%r1)
324	b	trapagain
325
326trapleave_to_kernel:
327	lmw	%r14, FRAME_R14(%r1)	/* restore callee registers */
328
329intrleave_to_kernel:
330	FRAME_RESTORE		/* old SP is now in sprg1 */
331
332	mtsprg2	%r30
333	mtsprg3	%r31
334	mfmsr	%r30
335	li	%r31,(PSL_DR|PSL_IR)@l
336	andc	%r30,%r30,%r31
337	lwz	%r31,FRAME_PID(%r1)
338	TRAP_IF_ZERO(%r31)
339	/*
340	 * Now that we are done with the trapframe, we can load the original SP
341	 */
342	mfsprg1	%r1
343	mtmsr	%r30	/* disable translation */
344	isync
345	mtpid	%r31
346	mfsprg3	%r31
347	mfsprg2	%r30
348	rfi
349	ba	.		/* Protect against prefetch */
350
351trapleave_to_user:
352	lmw	%r14, FRAME_R14(%r1)	/* restore callee registers */
353
354intrleave_to_user:
355/* Now restore regs: */
356	lwz	%r3,FRAME_PID(%r1)
357	lwz	%r4,FRAME_SRR1(%r1)
358	bl	_C_LABEL(ctx_setup)
359	TRAP_IF_ZERO(%r3)
360	stw	%r3,FRAME_PID(%r1)
361
362	FRAME_RESTORE		/* old SP is now in sprg1 */
363
364	/*
365	 * We are returning to userspace so we need to switch PIDs.
366	 * Since the kernel executes out of what would be userspace,
367	 * we need to turn off translation before we set the PID.
368	 *
369	 * Alterantively, we could map a kernel page at 0xfffff000
370	 * that had the mtpid code in it and branch to it and avoid
371	 * all this.  (ba foo; foo: mtpid %r31; mfsprg3 %r31; rfi;)
372	 */
373	mtsprg2	%r30
374	mtsprg3	%r31
375	mfmsr	%r30
376	li	%r31,(PSL_DR|PSL_IR)@l
377	andc	%r30,%r30,%r31
378	lwz	%r31,FRAME_PID(%r1)
379	TRAP_IF_ZERO(%r31)
380	/*
381	 * Now that we are done with the trapframe, we can load the original SP
382	 */
383	mfsprg1	%r1
384	mtmsr	%r30	/* disable translation */
385	isync
386	mtpid	%r31
387	mfsprg3	%r31
388	mfsprg2	%r30
389	rfi
390	ba	.	/* Protect against prefetch */
391
392
393	.globl	_C_LABEL(sctrap),_C_LABEL(scsize),_C_LABEL(sctrapexit)
394_C_LABEL(sctrap):
395	STANDARD_PROLOG(CI_TEMPSAVE)
396	bla	s_sctrap
397_C_LABEL(scsize) = .-_C_LABEL(sctrap)
398
399s_sctrap:
400	FRAME_SETUP(CI_TEMPSAVE)
401/* Now we can recover interrupts again: */
402	wrteei	1			/* Enable interrupts */
403/* Call the appropriate syscall handler: */
404	addi	%r3,%r1,FRAME_TF
405	lwz	%r4,L_PROC(%r13)
406	lwz	%r4,P_MD_SYSCALL(%r4)
407	mtctr	%r4
408	bctrl
409_C_LABEL(sctrapexit):
410	b	trapexit
411
412/*
413 * External interrupt second level handler
414 */
415
416#define	INTR_SAVE(tempsave)						\
417/* Save non-volatile registers: */					\
418	stwu	%r1,-FRAMELEN(%r1);	/* temporarily */		\
419	stw	%r0,FRAME_R0(%r1);					\
420	mfsprg1	%r0;			/* get original SP */		\
421	stw	%r0,FRAME_R1(%r1);	/* and store it */		\
422	stw	%r2,FRAME_R2(%r1);					\
423	stw	%r3,FRAME_R3(%r1);					\
424	stw	%r4,FRAME_R4(%r1);					\
425	stw	%r5,FRAME_R5(%r1);					\
426	stw	%r6,FRAME_R6(%r1);					\
427	stw	%r7,FRAME_R7(%r1);					\
428	stw	%r8,FRAME_R8(%r1);					\
429	stw	%r9,FRAME_R9(%r1);					\
430	stw	%r10,FRAME_R10(%r1);					\
431	stw	%r11,FRAME_R11(%r1);					\
432	stw	%r12,FRAME_R12(%r1);					\
433	stw	%r13,FRAME_R13(%r1);					\
434	mfctr	%r31;							\
435	stmw	%r28,FRAME_LR(%r1);	/* save LR, CR, XER, CTR */	\
436	GET_CPUINFO(%r5);						\
437	lmw	%r28,(tempsave+CPUSAVE_R28)(%r5); /* restore r28-r31 */	\
438	lwz	%r13,CI_CURLWP(%r5);					\
439	lwz	%r5,CI_IDEPTH(%r5);					\
440	mfsrr0	%r4;							\
441	mfsrr1	%r3;							\
442	stw	%r5,FRAME_IDEPTH(%r1);					\
443	stw	%r4,FRAME_SRR0(%r1);					\
444	stw	%r3,FRAME_SRR1(%r1);					\
445/* interrupts are recoverable here, and enable translation */		\
446	ENABLE_TRANSLATION(%r0,%r5);					\
447	stw	%r0,FRAME_PID(%r1);
448
449	.globl	_C_LABEL(extint_call)
450extintr:
451	INTR_SAVE(CI_TEMPSAVE)
452_C_LABEL(extint_call):
453	bl	_C_LABEL(extint_call)	/* to be filled in later */
454
455intr_exit:
456/* Disable interrupts */
457	wrteei	0
458	isync
459
460	lwz	%r4,FRAME_SRR1(%r1)
461/* Returning to user mode? */
462	mtcr	%r4			/* saved SRR1 */
463	bf	MSR_PR,intrleave_to_kernel /* branch if MSR[PR] is false */
464
465	lwz	%r4,L_MD_ASTPENDING(%r13)/* Test AST pending */
466	andi.	%r4,%r4,1
467	beq	intrleave_to_user
468
469	FRAME_SAVE_CALLEE		/* save rest of callee registers */
470	li	%r6,EXC_AST
471	stw	%r6,FRAME_EXC(%r1)
472	lwz	%r31,FRAME_SRR1(%r1)	/* move SRR1 to R31 */
473	b	trapagain
474
475/*
476 * PIT interrupt handler.
477 */
478	.align	5
479_C_LABEL(pitint):
480	INTR_PROLOG(CI_TEMPSAVE)
481	INTR_SAVE(CI_TEMPSAVE)
482	addi	%r3,%r1,FRAME_CF	/* clock frame */
483	bl	_C_LABEL(decr_intr)
484	b	intr_exit
485
486/*
487 * FIT interrupt handler.
488 */
489	.align	5
490_C_LABEL(fitint):
491	INTR_PROLOG(CI_TEMPSAVE)
492	INTR_SAVE(CI_TEMPSAVE)
493	addi	%r3,%r1,FRAME_CF	/* clock frame */
494	bl	_C_LABEL(stat_intr)
495	b	intr_exit
496
497#if defined(DDB) || defined(KGDB)
498/*
499 * Deliberate entry to ddbtrap
500 */
501	.globl	_C_LABEL(ddb_trap)
502_C_LABEL(ddb_trap):
503	mtsprg1	%r1
504	GET_CPUINFO(%r4)
505	mfmsr	%r3
506	stw	%r3,(CI_DDBSAVE+CPUSAVE_SRR1)(%r4)
507	wrteei	0			/* disable interrupts */
508	isync
509	stmw	%r28,CI_DDBSAVE(%r4)
510	mflr	%r28
511	stw	%r28,(CI_DDBSAVE+CPUSAVE_SRR0)(%r4)
512	li	%r29,EXC_BPT
513	mtlr	%r29
514	mfcr	%r29
515
516/*
517 * Now the ddb/kgdb trap catching code.
518 */
519ddbtrap:
520	FRAME_SETUP(CI_DDBSAVE)
521/* Call C trap code: */
522	addi	%r3,%r1,FRAME_TF
523	bl	_C_LABEL(ddb_trap_glue)
524	or.	%r3,%r3,%r3
525	beq	trapagain
526	b	trapexit
527#endif /* DDB || KGDB */
528
529#ifdef IPKDB
530/*
531 * Deliberate entry to ipkdbtrap
532 */
533	.globl	_C_LABEL(ipkdb_trap)
534_C_LABEL(ipkdb_trap):
535	mtsprg1	%r1
536	GET_CPUINFO(%r4)
537	mfmsr	%r3
538	stw	%r3,(CI_IPKDBSAVE+CPUSAVE_SRR1)(%r4)
539	wrteei	0			/* disable interrupts */
540	isync
541	stmw	%r28,CI_IPKDBSAVE(%r4)
542	mflr	%r28
543	stw	%r28,(CI_IPKDBSAVE+CPUSAVE_SRR0)(%r4)
544	li	%r29,EXC_BPT
545	mtlr	%r29
546	mfcr	%r29
547
548/*
549 * Now the ipkdb trap catching code.
550 */
551ipkdbtrap:
552	FRAME_SETUP(CI_IPKDBSAVE)
553/* Call C trap code: */
554	addi	%r3,%r1,FRAME_TF
555	bl	_C_LABEL(ipkdb_trap_glue)
556	or.	%r3,%r3,%r3
557	beq	trapagain
558	b	trapexit
559
560ipkdbfault:
561	ba	_ipkdbfault
562_ipkdbfault:
563	mfsrr0	%r3
564	addi	%r3,%r3,4
565	mtsrr0	%r3
566	li	%r3,-1
567	rfi
568	ba	.	/* Protect against prefetch */
569
570/*
571 * int ipkdbfbyte(unsigned char *p)
572 */
573	.globl	_C_LABEL(ipkdbfbyte)
574_C_LABEL(ipkdbfbyte):
575	li	%r9,EXC_DSI		/* establish new fault routine */
576	lwz	%r5,0(%r9)
577	lis	%r6,ipkdbfault@ha
578	lwz	%r6,ipkdbfault@l(%r6)
579	stw	%r6,0(%r9)
580#ifdef	IPKDBUSERHACK
581#ifndef PPC_IBM4XX
582	lis	%r8,_C_LABEL(ipkdbsr)@ha
583	lwz	%r8,_C_LABEL(ipkdbsr)@l(%r8)
584	mtsr	USER_SR,%r8
585	isync
586#endif
587#endif
588	dcbst	%r0,%r9			/* flush data... */
589	sync
590	icbi	%r0,%r9			/* and instruction caches */
591	lbz	%r3,0(%r3)		/* fetch data */
592	stw	%r5,0(%r9)		/* restore previous fault handler */
593	dcbst	%r0,%r9			/* and flush data... */
594	sync
595	icbi	%r0,%r9			/* and instruction caches */
596	blr
597
598/*
599 * int ipkdbsbyte(unsigned char *p, int c)
600 */
601	.globl	_C_LABEL(ipkdbsbyte)
602_C_LABEL(ipkdbsbyte):
603	li	%r9,EXC_DSI		/* establish new fault routine */
604	lwz	%r5,0(%r9)
605	lis	%r6,ipkdbfault@ha
606	lwz	%r6,ipkdbfault@l(%r6)
607	stw	%r6,0(%r9)
608#ifdef	IPKDBUSERHACK
609#ifndef PPC_IBM4XX
610	lis	%r8,_C_LABEL(ipkdbsr)@ha
611	lwz	%r8,_C_LABEL(ipkdbsr)@l(%r8)
612	mtsr	USER_SR,%r8
613	isync
614#endif
615#endif
616	dcbst	%r0,%r9			/* flush data... */
617	sync
618	icbi	%r0,%r9			/* and instruction caches */
619	mr	%r6,%r3
620	xor	%r3,%r3,%r3
621	stb	%r4,0(%r6)
622	dcbst	%r0,%r6			/* Now do appropriate flushes
623					   to data... */
624	sync
625	icbi	%r0,%r6			/* and instruction caches */
626	stw	%r5,0(%r9)		/* restore previous fault handler */
627	dcbst	%r0,%r9			/* and flush data... */
628	sync
629	icbi	%r0,%r9			/* and instruction caches */
630	blr
631#endif	/* IPKDB */
632