1/*	$NetBSD: trap_subr.S,v 1.21 2011/12/15 11:13:25 kiyohara 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);		\
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	lwz	%r1,CI_INTSTK(%r1);	/* get intstk */	\
170	bt	MSR_PR,1f;		/* branch if PSL_PR is true */ \
171	mfsprg1	%r1;			/* yes, get old SP */	\
1721:
173
174/*
175 * This code gets copied to all the trap vectors
176 * (except ISI/DSI, ALI, the interrupts, and possibly the debugging
177 * traps when using IPKDB).
178 */
179	.text
180	STANDARD_EXC_HANDLER(default)
181	ACCESS_EXC_HANDLER(ali)
182	ACCESS_EXC_HANDLER(dsi)
183	ACCESS_EXC_HANDLER(isi)
184	STANDARD_EXC_HANDLER(debug)
185	CRITICAL_EXC_HANDLER(mchk)
186
187/*
188 * This one for the external interrupt handler.
189 */
190	.globl	_C_LABEL(extint),_C_LABEL(extsize)
191_C_LABEL(extint):
192	INTR_PROLOG(CI_TEMPSAVE)
193	ba	extintr
194_C_LABEL(extsize) = .-_C_LABEL(extint)
195
196
197#if defined(DDB) || defined(KGDB)
198/*
199 * In case of DDB we want a separate trap catcher for it
200 */
201	.lcomm	ddbstk,INTSTK,16	/* ddb stack */
202
203	.globl	_C_LABEL(ddblow),_C_LABEL(ddbsize)
204_C_LABEL(ddblow):
205	mtsprg1	%r1			/* save SP */
206	GET_CPUINFO(%r1)
207	stmw	%r28,CI_DDBSAVE(%r1)	/* free r28-r31 */
208	mflr	%r28			/* save LR */
209	mfcr	%r29			/* save CR */
210	mfsrr0	%r30
211	mfsrr1	%r31
212	stmw	%r30,(CI_DDBSAVE+CPUSAVE_SRR0)(%r1)	/* save srr0/srr1 */
213	lis	%r1,ddbstk+INTSTK-CALLFRAMELEN@ha	/* get new SP */
214	addi	%r1,%r1,ddbstk+INTSTK-CALLFRAMELEN@l
215	bla	ddbtrap
216_C_LABEL(ddbsize) = .-_C_LABEL(ddblow)
217#endif	/* DDB || KGDB */
218
219#ifdef IPKDB
220/*
221 * In case of IPKDB we want a separate trap catcher for it
222 */
223
224	.lcomm	ipkdbstk,INTSTK,16	/* ipkdb stack */
225
226	.globl	_C_LABEL(ipkdblow),_C_LABEL(ipkdbsize)
227_C_LABEL(ipkdblow):
228	mtsprg1	%r1			/* save SP */
229	GET_CPUINFO(%r1)
230	stmw	%r28,CI_IPKDBSAVE(%r1)	/* free r28-r31 */
231	mflr	%r28			/* save LR */
232	mfcr	%r29			/* save CR */
233	mfsrr0	%r30
234	mfsrr1	%r31
235	stmw	%r30,(CI_IPKDBSAVE+CPUSAVE_SRR0)(%r1)	/* save srr0/srr1 */
236	lis	%r1,ipkdbstk+INTSTK-CALLFRAMELEN@ha	/* get new SP */
237	addi	%r1,%r1,ipkdbstk+INTSTK-CALLFRAMELEN@l
238	bla	ipkdbtrap
239_C_LABEL(ipkdbsize) = .-_C_LABEL(ipkdblow)
240#endif	/* IPKDB */
241
242#ifdef DEBUG
243#define TRAP_IF_ZERO(r)	tweqi	r,0
244#else
245#define TRAP_IF_ZERO(r)
246#endif
247
248#define	ENABLE_TRANSLATION(pidreg,tmpreg)				\
249	mfpid	pidreg;							\
250	li	tmpreg,KERNEL_PID;					\
251	mtpid	tmpreg;							\
252	mfmsr	tmpreg;							\
253	ori	tmpreg,tmpreg,(PSL_DR|PSL_IR)@l;			\
254	mtmsr	tmpreg;							\
255	isync
256
257/*
258 * FRAME_SETUP assumes:
259 *	SPRG1		SP (r1)
260 *	savearea	r28-r31,DEAR,ESR,SRR0,SRR1 (DEAR & ESR only for DSI traps)
261 *	%r28		LR
262 *	%r29		CR
263 *	%r1		kernel stack
264 *	LR		trap type
265 */
266#define	FRAME_SETUP(savearea)						\
267/* Have to enable translation to allow access of kernel stack: */	\
268	ENABLE_TRANSLATION(%r30,%r31);					\
269	mfsprg1	%r31;							\
270	stwu	%r31,-FRAMELEN(%r1);					\
271	stw	%r30,FRAME_PID(%r1);					\
272	stw	%r0,FRAME_R0(%r1);					\
273	stw	%r31,FRAME_R1(%r1);					\
274	stw	%r2,FRAME_R2(%r1);					\
275	GET_CPUINFO(%r2);						\
276	stw	%r28,FRAME_LR(%r1);					\
277	stw	%r29,FRAME_CR(%r1);					\
278	lmw	%r28,(savearea+CPUSAVE_R28)(%r2);			\
279	stmw	%r3,FRAME_R3(%r1);					\
280	lmw	%r28,(savearea+CPUSAVE_DEAR)(%r2);			\
281	lwz	%r13,CI_CURLWP(%r2);					\
282	mfxer	%r3;							\
283	mfctr	%r4;							\
284	mflr	%r5;							\
285	andi.	%r5,%r5,0xff00;						\
286	stw	%r3,FRAME_XER(%r1);					\
287	stw	%r4,FRAME_CTR(%r1);					\
288	stw	%r5,FRAME_EXC(%r1);					\
289	stw	%r28,FRAME_DEAR(%r1);					\
290	stw	%r29,FRAME_ESR(%r1);					\
291	stw	%r30,FRAME_SRR0(%r1);					\
292	stw	%r31,FRAME_SRR1(%r1)
293
294#define	FRAME_SAVE_CALLEE						\
295	stmw	%r14,FRAME_R14(%r1)
296
297#define	FRAME_RESTORE							\
298	lwz	%r6,FRAME_LR(%r1);					\
299	lwz	%r7,FRAME_CR(%r1);					\
300	lwz	%r8,FRAME_XER(%r1);					\
301	lwz	%r9,FRAME_CTR(%r1);					\
302	lwz	%r10,FRAME_SRR0(%r1);					\
303	lwz	%r11,FRAME_SRR1(%r1);					\
304	mtlr	%r6;							\
305	mtcr	%r7;							\
306	mtxer	%r8;							\
307	mtctr	%r9;							\
308	mtsrr0	%r10;							\
309	mtsrr1	%r11;							\
310	lwz	%r13,FRAME_R13(%r1);					\
311	lwz	%r12,FRAME_R12(%r1);					\
312	lwz	%r11,FRAME_R11(%r1);					\
313	lwz	%r10,FRAME_R10(%r1);					\
314	lwz	%r9,FRAME_R9(%r1);					\
315	lwz	%r8,FRAME_R8(%r1);					\
316	lwz	%r7,FRAME_R7(%r1);					\
317	lwz	%r6,FRAME_R6(%r1);					\
318	lwz	%r5,FRAME_R5(%r1);					\
319	lwz	%r4,FRAME_R4(%r1);					\
320	lwz	%r3,FRAME_R3(%r1);					\
321	lwz	%r2,FRAME_R2(%r1);					\
322	lwz	%r0,FRAME_R1(%r1);					\
323	mtsprg1	%r0;							\
324	lwz	%r0,FRAME_R0(%r1)
325
326/*
327 * Now the common trap catching code.
328 */
329s_trap:
330	FRAME_SETUP(CI_TEMPSAVE)
331	/* R31 = SRR1 */
332/* Now we can recover interrupts again: */
333trapagain:
334	wrtee	%r31			/* reenable interrupts */
335/* Call C trap code: */
336	addi	%r3,%r1,FRAME_TF
337	bl	_C_LABEL(trap)
338	.globl	_C_LABEL(trapexit)
339_C_LABEL(trapexit):
340	/* Disable interrupts: */
341	wrteei	0
342
343	/* Test AST pending: */
344	mtcr	%r31
345	bf	MSR_PR,trapleave_to_kernel /* branch if MSR[PR] is false */
346
347	lwz	%r4,L_MD_ASTPENDING(%r13)
348	andi.	%r4,%r4,1
349	beq	trapleave_to_user
350
351	li	%r6,EXC_AST
352	stw	%r6,FRAME_EXC(%r1)
353	b	trapagain
354
355trapleave_to_kernel:
356	lmw	%r14, FRAME_R14(%r1)	/* restore callee registers */
357
358intrleave_to_kernel:
359	FRAME_RESTORE		/* old SP is now in sprg1 */
360
361	mtsprg2	%r30
362	mtsprg3	%r31
363	mfmsr	%r30
364	li	%r31,(PSL_DR|PSL_IR)@l
365	andc	%r30,%r30,%r31
366	lwz	%r31,FRAME_PID(%r1)
367	TRAP_IF_ZERO(%r31)
368	/*
369	 * Now that we are done with the trapframe, we can load the original SP
370	 */
371	mfsprg1	%r1
372	mtmsr	%r30	/* disable translation */
373	isync
374	mtpid	%r31
375	mfsprg3	%r31
376	mfsprg2	%r30
377	rfi
378	ba	.		/* Protect against prefetch */
379
380trapleave_to_user:
381	lmw	%r14, FRAME_R14(%r1)	/* restore callee registers */
382
383intrleave_to_user:
384/* Now restore regs: */
385	lwz	%r3,FRAME_PID(%r1)
386	lwz	%r4,FRAME_SRR1(%r1)
387	bl	_C_LABEL(ctx_setup)
388	TRAP_IF_ZERO(%r3)
389	stw	%r3,FRAME_PID(%r1)
390
391	FRAME_RESTORE		/* old SP is now in sprg1 */
392
393	/*
394	 * We are returning to userspace so we need to switch PIDs.
395	 * Since the kernel executes out of what would be userspace,
396	 * we need to turn off translation before we set the PID.
397	 *
398	 * Alterantively, we could map a kernel page at 0xfffff000
399	 * that had the mtpid code in it and branch to it and avoid
400	 * all this.  (ba foo; foo: mtpid %r31; mfsprg3 %r31; rfi;)
401	 */
402	mtsprg2	%r30
403	mtsprg3	%r31
404	mfmsr	%r30
405	li	%r31,(PSL_DR|PSL_IR)@l
406	andc	%r30,%r30,%r31
407	lwz	%r31,FRAME_PID(%r1)
408	TRAP_IF_ZERO(%r31)
409	/*
410	 * Now that we are done with the trapframe, we can load the original SP
411	 */
412	mfsprg1	%r1
413	mtmsr	%r30	/* disable translation */
414	isync
415	mtpid	%r31
416	mfsprg3	%r31
417	mfsprg2	%r30
418	rfi
419	ba	.	/* Protect against prefetch */
420
421
422	.globl	_C_LABEL(sctrap),_C_LABEL(scsize),_C_LABEL(sctrapexit)
423_C_LABEL(sctrap):
424	STANDARD_PROLOG(CI_TEMPSAVE)
425	bla	s_sctrap
426_C_LABEL(scsize) = .-_C_LABEL(sctrap)
427
428s_sctrap:
429	FRAME_SETUP(CI_TEMPSAVE)
430/* Now we can recover interrupts again: */
431	wrteei	1			/* Enable interrupts */
432/* Call the appropriate syscall handler: */
433	addi	%r3,%r1,FRAME_TF
434	lwz	%r4,L_PROC(%r13)
435	lwz	%r4,P_MD_SYSCALL(%r4)
436	mtctr	%r4
437	bctrl
438_C_LABEL(sctrapexit):
439	b	trapexit
440
441/*
442 * External interrupt second level handler
443 */
444
445#define	INTR_SAVE(tempsave)						\
446/* Save non-volatile registers: */					\
447	stwu	%r1,-FRAMELEN(%r1);	/* temporarily */		\
448	stw	%r0,FRAME_R0(%r1);					\
449	mfsprg1	%r0;			/* get original SP */		\
450	stw	%r0,FRAME_R1(%r1);	/* and store it */		\
451	stw	%r2,FRAME_R2(%r1);					\
452	stw	%r3,FRAME_R3(%r1);					\
453	stw	%r4,FRAME_R4(%r1);					\
454	stw	%r5,FRAME_R5(%r1);					\
455	stw	%r6,FRAME_R6(%r1);					\
456	stw	%r7,FRAME_R7(%r1);					\
457	stw	%r8,FRAME_R8(%r1);					\
458	stw	%r9,FRAME_R9(%r1);					\
459	stw	%r10,FRAME_R10(%r1);					\
460	stw	%r11,FRAME_R11(%r1);					\
461	stw	%r12,FRAME_R12(%r1);					\
462	stw	%r13,FRAME_R13(%r1);					\
463	mfctr	%r31;							\
464	stmw	%r28,FRAME_LR(%r1);	/* save LR, CR, XER, CTR */	\
465	GET_CPUINFO(%r5);						\
466	lmw	%r28,(tempsave+CPUSAVE_R28)(%r5); /* restore r28-r31 */	\
467	lwz	%r13,CI_CURLWP(%r5);					\
468	lwz	%r5,CI_IDEPTH(%r5);					\
469	mfsrr0	%r4;							\
470	mfsrr1	%r3;							\
471	stw	%r5,FRAME_IDEPTH(%r1);					\
472	stw	%r4,FRAME_SRR0(%r1);					\
473	stw	%r3,FRAME_SRR1(%r1);					\
474/* interrupts are recoverable here, and enable translation */		\
475	ENABLE_TRANSLATION(%r0,%r5);					\
476	stw	%r0,FRAME_PID(%r1);
477
478	.globl	_C_LABEL(extint_call)
479extintr:
480	INTR_SAVE(CI_TEMPSAVE)
481_C_LABEL(extint_call):
482	bl	_C_LABEL(extint_call)	/* to be filled in later */
483
484intr_exit:
485/* Disable interrupts */
486	wrteei	0
487	isync
488	GET_CPUINFO(%r5)
489
490	lwz	%r4,FRAME_SRR1(%r1)
491/* Returning to user mode? */
492	mtcr	%r4			/* saved SRR1 */
493	bf	MSR_PR,intrleave_to_kernel /* branch if MSR[PR] is false */
494
495	lwz	%r4,L_MD_ASTPENDING(%r13)/* Test AST pending */
496	andi.	%r4,%r4,1
497	beq	intrleave_to_user
498
499	FRAME_SAVE_CALLEE		/* save rest of callee registers */
500	li	%r6,EXC_AST
501	stw	%r6,FRAME_EXC(%r1)
502	mr	%r31,%r5		/* move SRR1 to R31 */
503	b	trapagain
504
505/*
506 * PIT interrupt handler.
507 */
508	.align	5
509_C_LABEL(pitint):
510	INTR_PROLOG(CI_TEMPSAVE)
511	INTR_SAVE(CI_TEMPSAVE)
512	addi	%r3,%r1,FRAME_CF	/* clock frame */
513	bl	_C_LABEL(decr_intr)
514	b	intr_exit
515
516/*
517 * FIT interrupt handler.
518 */
519	.align	5
520_C_LABEL(fitint):
521	INTR_PROLOG(CI_TEMPSAVE)
522	INTR_SAVE(CI_TEMPSAVE)
523	addi	%r3,%r1,FRAME_CF	/* clock frame */
524	bl	_C_LABEL(stat_intr)
525	b	intr_exit
526
527#if defined(DDB) || defined(KGDB)
528/*
529 * Deliberate entry to ddbtrap
530 */
531	.globl	_C_LABEL(ddb_trap)
532_C_LABEL(ddb_trap):
533	mtsprg1	%r1
534	GET_CPUINFO(%r4)
535	mfmsr	%r3
536	stw	%r3,(CI_DDBSAVE+CPUSAVE_SRR1)(%r4)
537	wrteei	0			/* disable interrupts */
538	isync
539	stmw	%r28,CI_DDBSAVE(%r4)
540	mflr	%r28
541	stw	%r28,(CI_DDBSAVE+CPUSAVE_SRR0)(%r4)
542	li	%r29,EXC_BPT
543	mtlr	%r29
544	mfcr	%r29
545
546/*
547 * Now the ddb/kgdb trap catching code.
548 */
549ddbtrap:
550	FRAME_SETUP(CI_DDBSAVE)
551/* Call C trap code: */
552	addi	%r3,%r1,FRAME_TF
553	bl	_C_LABEL(ddb_trap_glue)
554	or.	%r3,%r3,%r3
555	beq	trapagain
556	b	trapexit
557#endif /* DDB || KGDB */
558
559#ifdef IPKDB
560/*
561 * Deliberate entry to ipkdbtrap
562 */
563	.globl	_C_LABEL(ipkdb_trap)
564_C_LABEL(ipkdb_trap):
565	mtsprg1	%r1
566	GET_CPUINFO(%r4)
567	mfmsr	%r3
568	stw	%r3,(CI_IPKDBSAVE+CPUSAVE_SRR1)(%r4)
569	wrteei	0			/* disable interrupts */
570	isync
571	stmw	%r28,CI_IPKDBSAVE(%r4)
572	mflr	%r28
573	stw	%r28,(CI_IPKDBSAVE+CPUSAVE_SRR0)(%r4)
574	li	%r29,EXC_BPT
575	mtlr	%r29
576	mfcr	%r29
577
578/*
579 * Now the ipkdb trap catching code.
580 */
581ipkdbtrap:
582	FRAME_SETUP(CI_IPKDBSAVE)
583/* Call C trap code: */
584	addi	%r3,%r1,FRAME_TF
585	bl	_C_LABEL(ipkdb_trap_glue)
586	or.	%r3,%r3,%r3
587	beq	trapagain
588	b	trapexit
589
590ipkdbfault:
591	ba	_ipkdbfault
592_ipkdbfault:
593	mfsrr0	%r3
594	addi	%r3,%r3,4
595	mtsrr0	%r3
596	li	%r3,-1
597	rfi
598	ba	.	/* Protect against prefetch */
599
600/*
601 * int ipkdbfbyte(unsigned char *p)
602 */
603	.globl	_C_LABEL(ipkdbfbyte)
604_C_LABEL(ipkdbfbyte):
605	li	%r9,EXC_DSI		/* establish new fault routine */
606	lwz	%r5,0(%r9)
607	lis	%r6,ipkdbfault@ha
608	lwz	%r6,ipkdbfault@l(%r6)
609	stw	%r6,0(%r9)
610#ifdef	IPKDBUSERHACK
611#ifndef PPC_IBM4XX
612	lis	%r8,_C_LABEL(ipkdbsr)@ha
613	lwz	%r8,_C_LABEL(ipkdbsr)@l(%r8)
614	mtsr	USER_SR,%r8
615	isync
616#endif
617#endif
618	dcbst	%r0,%r9			/* flush data... */
619	sync
620	icbi	%r0,%r9			/* and instruction caches */
621	lbz	%r3,0(%r3)		/* fetch data */
622	stw	%r5,0(%r9)		/* restore previous fault handler */
623	dcbst	%r0,%r9			/* and flush data... */
624	sync
625	icbi	%r0,%r9			/* and instruction caches */
626	blr
627
628/*
629 * int ipkdbsbyte(unsigned char *p, int c)
630 */
631	.globl	_C_LABEL(ipkdbsbyte)
632_C_LABEL(ipkdbsbyte):
633	li	%r9,EXC_DSI		/* establish new fault routine */
634	lwz	%r5,0(%r9)
635	lis	%r6,ipkdbfault@ha
636	lwz	%r6,ipkdbfault@l(%r6)
637	stw	%r6,0(%r9)
638#ifdef	IPKDBUSERHACK
639#ifndef PPC_IBM4XX
640	lis	%r8,_C_LABEL(ipkdbsr)@ha
641	lwz	%r8,_C_LABEL(ipkdbsr)@l(%r8)
642	mtsr	USER_SR,%r8
643	isync
644#endif
645#endif
646	dcbst	%r0,%r9			/* flush data... */
647	sync
648	icbi	%r0,%r9			/* and instruction caches */
649	mr	%r6,%r3
650	xor	%r3,%r3,%r3
651	stb	%r4,0(%r6)
652	dcbst	%r0,%r6			/* Now do appropriate flushes
653					   to data... */
654	sync
655	icbi	%r0,%r6			/* and instruction caches */
656	stw	%r5,0(%r9)		/* restore previous fault handler */
657	dcbst	%r0,%r9			/* and flush data... */
658	sync
659	icbi	%r0,%r9			/* and instruction caches */
660	blr
661#endif	/* IPKDB */
662