xref: /freebsd/sys/powerpc/aim/trap_subr64.S (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
1/* $FreeBSD$ */
2/* $NetBSD: trap_subr.S,v 1.20 2002/04/22 23:20:08 kleink Exp $	*/
3
4/*-
5 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
6 * Copyright (C) 1995, 1996 TooLs GmbH.
7 * All rights reserved.
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 by TooLs GmbH.
20 * 4. The name of TooLs GmbH may not be used to endorse or promote products
21 *    derived from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
28 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
29 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
31 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
32 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35/*
36 * NOTICE: This is not a standalone file.  to use it, #include it in
37 * your port's locore.S, like so:
38 *
39 *	#include <powerpc/aim/trap_subr.S>
40 */
41
42/*
43 * Save/restore segment registers
44 */
45
46/*
47 * Restore SRs for a pmap
48 *
49 * Requires that r28-r31 be scratch, with r28 initialized to the SLB cache
50 */
51
52/*
53 * User SRs are loaded through a pointer to the current pmap.
54 */
55restore_usersrs:
56	GET_CPUINFO(%r28)
57	ld	%r28,PC_USERSLB(%r28)
58	li	%r29, 0			/* Set the counter to zero */
59
60	slbia
61	slbmfee	%r31,%r29
62	clrrdi	%r31,%r31,28
63	slbie	%r31
641:	ld	%r31, 0(%r28)		/* Load SLB entry pointer */
65	cmpli	0, %r31, 0		/* If NULL, stop */
66	beqlr
67
68	ld	%r30, 0(%r31)		/* Load SLBV */
69	ld	%r31, 8(%r31)		/* Load SLBE */
70	or	%r31, %r31, %r29	/*  Set SLBE slot */
71	slbmte	%r30, %r31		/* Install SLB entry */
72
73	addi	%r28, %r28, 8		/* Advance pointer */
74	addi	%r29, %r29, 1
75	b	1b			/* Repeat */
76
77/*
78 * Kernel SRs are loaded directly from the PCPU fields
79 */
80restore_kernsrs:
81	GET_CPUINFO(%r28)
82	addi	%r28,%r28,PC_KERNSLB
83	li	%r29, 0			/* Set the counter to zero */
84
85	slbia
86	slbmfee	%r31,%r29
87	clrrdi	%r31,%r31,28
88	slbie	%r31
891:	cmpli	0, %r29, USER_SLB_SLOT	/* Skip the user slot */
90	beq-	2f
91
92	ld	%r31, 8(%r28)		/* Load SLBE */
93	cmpli	0, %r31, 0		/* If SLBE is not valid, stop */
94	beqlr
95	ld	%r30, 0(%r28)		/* Load SLBV  */
96	slbmte	%r30, %r31		/* Install SLB entry */
97
982:	addi	%r28, %r28, 16		/* Advance pointer */
99	addi	%r29, %r29, 1
100	cmpli	0, %r29, 64		/* Repeat if we are not at the end */
101	blt	1b
102	blr
103
104/*
105 * FRAME_SETUP assumes:
106 *	SPRG1		SP (1)
107 * 	SPRG3		trap type
108 *	savearea	r27-r31,DAR,DSISR   (DAR & DSISR only for DSI traps)
109 *	r28		LR
110 *	r29		CR
111 *	r30		scratch
112 *	r31		scratch
113 *	r1		kernel stack
114 *	SRR0/1		as at start of trap
115 *
116 * NOTE: SPRG1 is never used while the MMU is on, making it safe to reuse
117 * in any real-mode fault handler, including those handling double faults.
118 */
119#define	FRAME_SETUP(savearea)						\
120/* Have to enable translation to allow access of kernel stack: */	\
121	GET_CPUINFO(%r31);						\
122	mfsrr0	%r30;							\
123	std	%r30,(savearea+CPUSAVE_SRR0)(%r31);	/* save SRR0 */	\
124	mfsrr1	%r30;							\
125	std	%r30,(savearea+CPUSAVE_SRR1)(%r31);	/* save SRR1 */	\
126	mfsprg1	%r31;			/* get saved SP (clears SPRG1) */ \
127	mfmsr	%r30;							\
128	ori	%r30,%r30,(PSL_DR|PSL_IR|PSL_RI)@l; /* relocation on */	\
129	mtmsr	%r30;			/* stack can now be accessed */	\
130	isync;								\
131	stdu	%r31,-(FRAMELEN+288)(%r1); /* save it in the callframe */ \
132	std	%r0, FRAME_0+48(%r1);	/* save r0 in the trapframe */	\
133	std	%r31,FRAME_1+48(%r1);	/* save SP   "      "       */	\
134	std	%r2, FRAME_2+48(%r1);	/* save r2   "      "       */	\
135	std	%r28,FRAME_LR+48(%r1);	/* save LR   "      "       */	\
136	std	%r29,FRAME_CR+48(%r1);	/* save CR   "      "       */	\
137	GET_CPUINFO(%r2);						\
138	ld	%r27,(savearea+CPUSAVE_R27)(%r2); /* get saved r27 */	\
139	ld	%r28,(savearea+CPUSAVE_R28)(%r2); /* get saved r28 */	\
140	ld	%r29,(savearea+CPUSAVE_R29)(%r2); /* get saved r29 */	\
141	ld	%r30,(savearea+CPUSAVE_R30)(%r2); /* get saved r30 */	\
142	ld	%r31,(savearea+CPUSAVE_R31)(%r2); /* get saved r31 */	\
143	std	%r3,  FRAME_3+48(%r1);	/* save r3-r31 */		\
144	std	%r4,  FRAME_4+48(%r1);					\
145	std	%r5,  FRAME_5+48(%r1);					\
146	std	%r6,  FRAME_6+48(%r1);					\
147	std	%r7,  FRAME_7+48(%r1);					\
148	std	%r8,  FRAME_8+48(%r1);					\
149	std	%r9,  FRAME_9+48(%r1);					\
150	std	%r10, FRAME_10+48(%r1);					\
151	std	%r11, FRAME_11+48(%r1);					\
152	std	%r12, FRAME_12+48(%r1);					\
153	std	%r13, FRAME_13+48(%r1);					\
154	std	%r14, FRAME_14+48(%r1);					\
155	std	%r15, FRAME_15+48(%r1);					\
156	std	%r16, FRAME_16+48(%r1);					\
157	std	%r17, FRAME_17+48(%r1);					\
158	std	%r18, FRAME_18+48(%r1);					\
159	std	%r19, FRAME_19+48(%r1);					\
160	std	%r20, FRAME_20+48(%r1);					\
161	std	%r21, FRAME_21+48(%r1);					\
162	std	%r22, FRAME_22+48(%r1);					\
163	std	%r23, FRAME_23+48(%r1);					\
164	std	%r24, FRAME_24+48(%r1);					\
165	std	%r25, FRAME_25+48(%r1);					\
166	std	%r26, FRAME_26+48(%r1);					\
167	std	%r27, FRAME_27+48(%r1);					\
168	std	%r28, FRAME_28+48(%r1);					\
169	std	%r29, FRAME_29+48(%r1);					\
170	std	%r30, FRAME_30+48(%r1);					\
171	std	%r31, FRAME_31+48(%r1);					\
172	ld	%r28,(savearea+CPUSAVE_AIM_DAR)(%r2);  /* saved DAR */	\
173	ld	%r29,(savearea+CPUSAVE_AIM_DSISR)(%r2);/* saved DSISR */\
174	ld	%r30,(savearea+CPUSAVE_SRR0)(%r2); /* saved SRR0 */	\
175	ld	%r31,(savearea+CPUSAVE_SRR1)(%r2); /* saved SRR1 */	\
176	mfxer	%r3;							\
177	mfctr	%r4;							\
178	mfsprg3	%r5;							\
179	std	%r3, FRAME_XER+48(1);	/* save xer/ctr/exc */		\
180	std	%r4, FRAME_CTR+48(1);					\
181	std	%r5, FRAME_EXC+48(1);					\
182	std	%r28,FRAME_AIM_DAR+48(1);				\
183	std	%r29,FRAME_AIM_DSISR+48(1); /* save dsisr/srr0/srr1 */	\
184	std	%r30,FRAME_SRR0+48(1);					\
185	std	%r31,FRAME_SRR1+48(1);					\
186	ld	%r13,PC_CURTHREAD(%r2)	/* set kernel curthread */
187
188#define	FRAME_LEAVE(savearea)						\
189/* Disable exceptions: */						\
190	mfmsr	%r2;							\
191	andi.	%r2,%r2,~PSL_EE@l;					\
192	mtmsr	%r2;							\
193	isync;								\
194/* Now restore regs: */							\
195	ld	%r2,FRAME_SRR0+48(%r1);					\
196	ld	%r3,FRAME_SRR1+48(%r1);					\
197	ld	%r4,FRAME_CTR+48(%r1);					\
198	ld	%r5,FRAME_XER+48(%r1);					\
199	ld	%r6,FRAME_LR+48(%r1);					\
200	GET_CPUINFO(%r7);						\
201	std	%r2,(savearea+CPUSAVE_SRR0)(%r7); /* save SRR0 */	\
202	std	%r3,(savearea+CPUSAVE_SRR1)(%r7); /* save SRR1 */	\
203	ld	%r7,FRAME_CR+48(%r1);					\
204	mtctr	%r4;							\
205	mtxer	%r5;							\
206	mtlr	%r6;							\
207	mtsprg2	%r7;			/* save cr */			\
208	ld	%r31,FRAME_31+48(%r1);   /* restore r0-31 */		\
209	ld	%r30,FRAME_30+48(%r1);					\
210	ld	%r29,FRAME_29+48(%r1);					\
211	ld	%r28,FRAME_28+48(%r1);					\
212	ld	%r27,FRAME_27+48(%r1);					\
213	ld	%r26,FRAME_26+48(%r1);					\
214	ld	%r25,FRAME_25+48(%r1);					\
215	ld	%r24,FRAME_24+48(%r1);					\
216	ld	%r23,FRAME_23+48(%r1);					\
217	ld	%r22,FRAME_22+48(%r1);					\
218	ld	%r21,FRAME_21+48(%r1);					\
219	ld	%r20,FRAME_20+48(%r1);					\
220	ld	%r19,FRAME_19+48(%r1);					\
221	ld	%r18,FRAME_18+48(%r1);					\
222	ld	%r17,FRAME_17+48(%r1);					\
223	ld	%r16,FRAME_16+48(%r1);					\
224	ld	%r15,FRAME_15+48(%r1);					\
225	ld	%r14,FRAME_14+48(%r1);					\
226	ld	%r13,FRAME_13+48(%r1);					\
227	ld	%r12,FRAME_12+48(%r1);					\
228	ld	%r11,FRAME_11+48(%r1);					\
229	ld	%r10,FRAME_10+48(%r1);					\
230	ld	%r9, FRAME_9+48(%r1);					\
231	ld	%r8, FRAME_8+48(%r1);					\
232	ld	%r7, FRAME_7+48(%r1);					\
233	ld	%r6, FRAME_6+48(%r1);					\
234	ld	%r5, FRAME_5+48(%r1);					\
235	ld	%r4, FRAME_4+48(%r1);					\
236	ld	%r3, FRAME_3+48(%r1);					\
237	ld	%r2, FRAME_2+48(%r1);					\
238	ld	%r0, FRAME_0+48(%r1);					\
239	ld	%r1, FRAME_1+48(%r1);					\
240/* Can't touch %r1 from here on */					\
241	mtsprg3	%r3;			/* save r3 */			\
242/* Disable translation, machine check and recoverability: */		\
243	mfmsr	%r3;							\
244	andi.	%r3,%r3,~(PSL_DR|PSL_IR|PSL_ME|PSL_RI)@l;		\
245	mtmsr	%r3;							\
246	isync;								\
247/* Decide whether we return to user mode: */				\
248	GET_CPUINFO(%r3);						\
249	ld	%r3,(savearea+CPUSAVE_SRR1)(%r3);			\
250	mtcr	%r3;							\
251	bf	17,1f;			/* branch if PSL_PR is false */	\
252/* Restore user SRs */							\
253	GET_CPUINFO(%r3);						\
254	std	%r27,(savearea+CPUSAVE_R27)(%r3);			\
255	std	%r28,(savearea+CPUSAVE_R28)(%r3);			\
256	std	%r29,(savearea+CPUSAVE_R29)(%r3);			\
257	std	%r30,(savearea+CPUSAVE_R30)(%r3);			\
258	std	%r31,(savearea+CPUSAVE_R31)(%r3);			\
259	mflr	%r27;			/* preserve LR */		\
260	bl	restore_usersrs;	/* uses r28-r31 */		\
261	mtlr	%r27;							\
262	ld	%r31,(savearea+CPUSAVE_R31)(%r3);			\
263	ld	%r30,(savearea+CPUSAVE_R30)(%r3);			\
264	ld	%r29,(savearea+CPUSAVE_R29)(%r3);			\
265	ld	%r28,(savearea+CPUSAVE_R28)(%r3);			\
266	ld	%r27,(savearea+CPUSAVE_R27)(%r3);			\
2671:	mfsprg2	%r3;			/* restore cr */		\
268	mtcr	%r3;							\
269	GET_CPUINFO(%r3);						\
270	ld	%r3,(savearea+CPUSAVE_SRR0)(%r3); /* restore srr0 */	\
271	mtsrr0	%r3;							\
272	GET_CPUINFO(%r3);						\
273	ld	%r3,(savearea+CPUSAVE_SRR1)(%r3); /* restore srr1 */	\
274	mtsrr1	%r3;							\
275	mfsprg3	%r3			/* restore r3 */
276
277#ifdef KDTRACE_HOOKS
278	.data
279	.globl	dtrace_invop_calltrap_addr
280	.align	8
281	.type	dtrace_invop_calltrap_addr, @object
282        .size	dtrace_invop_calltrap_addr, 8
283dtrace_invop_calltrap_addr:
284	.word	0
285	.word	0
286
287	.text
288#endif
289
290/*
291 * Processor reset exception handler. These are typically
292 * the first instructions the processor executes after a
293 * software reset. We do this in two bits so that we are
294 * not still hanging around in the trap handling region
295 * once the MMU is turned on.
296 */
297	.globl	CNAME(rstcode), CNAME(rstsize)
298CNAME(rstcode):
299	/* Explicitly set MSR[SF] */
300	mfmsr	%r9
301	li	%r8,1
302	insrdi	%r9,%r8,1,0
303	mtmsrd	%r9
304	isync
305
306	ba	cpu_reset
307CNAME(rstsize) = . - CNAME(rstcode)
308
309cpu_reset:
310	lis	%r1,(tmpstk+TMPSTKSZ-48)@ha	/* get new SP */
311	addi	%r1,%r1,(tmpstk+TMPSTKSZ-48)@l
312
313	lis	%r3,tocbase@ha
314	ld	%r2,tocbase@l(%r3)
315	lis	%r3,1@l
316	bl	CNAME(cpudep_ap_early_bootstrap) /* Set PCPU */
317	nop
318	lis	%r3,1@l
319	bl	CNAME(pmap_cpu_bootstrap)	/* Turn on virtual memory */
320	nop
321	bl	CNAME(cpudep_ap_bootstrap)	/* Set up PCPU and stack */
322	nop
323	mr	%r1,%r3				/* Use new stack */
324	bl	CNAME(cpudep_ap_setup)
325	nop
326	GET_CPUINFO(%r5)
327	ld	%r3,(PC_RESTORE)(%r5)
328	cmpldi	%cr0,%r3,0
329	beq	%cr0,2f
330	nop
331	li	%r4,1
332	b	CNAME(longjmp)
333	nop
3342:
335#ifdef SMP
336	bl	CNAME(machdep_ap_bootstrap)	/* And away! */
337	nop
338#endif
339
340	/* Should not be reached */
3419:
342	b	9b
343
344/*
345 * This code gets copied to all the trap vectors
346 * (except ISI/DSI, ALI, and the interrupts)
347 */
348
349	.globl	CNAME(trapcode),CNAME(trapsize)
350CNAME(trapcode):
351	mtsprg1	%r1			/* save SP */
352	mflr	%r1			/* Save the old LR in r1 */
353	mtsprg2 %r1			/* And then in SPRG2 */
354	li	%r1, 0xA0		/* How to get the vector from LR */
355	bla	generictrap		/* LR & SPRG3 is exception # */
356CNAME(trapsize) = .-CNAME(trapcode)
357
358/*
359 * For SLB misses: do special things for the kernel
360 *
361 * Note: SPRG1 is always safe to overwrite any time the MMU is on, which is
362 * the only time this can be called.
363 */
364	.globl	CNAME(slbtrap),CNAME(slbtrapsize)
365CNAME(slbtrap):
366	mtsprg1	%r1			/* save SP */
367	GET_CPUINFO(%r1)
368	std	%r2,(PC_SLBSAVE+16)(%r1)
369	mfcr	%r2			/* save CR */
370	std	%r2,(PC_SLBSAVE+104)(%r1)
371	mfsrr1	%r2			/* test kernel mode */
372	mtcr	%r2
373	bf	17,1f			/* branch if PSL_PR is false */
374	/* User mode */
375	ld	%r2,(PC_SLBSAVE+104)(%r1) /* Restore CR */
376	mtcr	%r2
377	ld	%r2,(PC_SLBSAVE+16)(%r1) /* Restore R2 */
378	mflr	%r1			/* Save the old LR in r1 */
379	mtsprg2 %r1			/* And then in SPRG2 */
380	li	%r1, 0x80		/* How to get the vector from LR */
381	bla	generictrap		/* LR & SPRG3 is exception # */
3821:	mflr	%r2			/* Save the old LR in r2 */
383	bla	kern_slbtrap
384CNAME(slbtrapsize) = .-CNAME(slbtrap)
385
386kern_slbtrap:
387	std	%r2,(PC_SLBSAVE+136)(%r1) /* old LR */
388	std	%r3,(PC_SLBSAVE+24)(%r1) /* save R3 */
389
390	/* Check if this needs to be handled as a regular trap (userseg miss) */
391	mflr	%r2
392	andi.	%r2,%r2,0xff80
393	cmpwi	%r2,0x380
394	bne	1f
395	mfdar	%r2
396	b	2f
3971:	mfsrr0	%r2
3982:	/* r2 now contains the fault address */
399	lis	%r3,SEGMENT_MASK@highesta
400	ori	%r3,%r3,SEGMENT_MASK@highera
401	sldi	%r3,%r3,32
402	oris	%r3,%r3,SEGMENT_MASK@ha
403	ori	%r3,%r3,SEGMENT_MASK@l
404	and	%r2,%r2,%r3	/* R2 = segment base address */
405	lis	%r3,USER_ADDR@highesta
406	ori	%r3,%r3,USER_ADDR@highera
407	sldi	%r3,%r3,32
408	oris	%r3,%r3,USER_ADDR@ha
409	ori	%r3,%r3,USER_ADDR@l
410	cmpd	%r2,%r3		/* Compare fault base to USER_ADDR */
411	bne	3f
412
413	/* User seg miss, handle as a regular trap */
414	ld	%r2,(PC_SLBSAVE+104)(%r1) /* Restore CR */
415	mtcr	%r2
416	ld	%r2,(PC_SLBSAVE+16)(%r1) /* Restore R2,R3 */
417	ld	%r3,(PC_SLBSAVE+24)(%r1)
418	ld	%r1,(PC_SLBSAVE+136)(%r1) /* Save the old LR in r1 */
419	mtsprg2 %r1			/* And then in SPRG2 */
420	li	%r1, 0x80		/* How to get the vector from LR */
421	b	generictrap		/* Retain old LR using b */
422
4233:	/* Real kernel SLB miss */
424	std	%r0,(PC_SLBSAVE+0)(%r1)	/* free all volatile regs */
425	mfsprg1	%r2			/* Old R1 */
426	std	%r2,(PC_SLBSAVE+8)(%r1)
427	/* R2,R3 already saved */
428	std	%r4,(PC_SLBSAVE+32)(%r1)
429	std	%r5,(PC_SLBSAVE+40)(%r1)
430	std	%r6,(PC_SLBSAVE+48)(%r1)
431	std	%r7,(PC_SLBSAVE+56)(%r1)
432	std	%r8,(PC_SLBSAVE+64)(%r1)
433	std	%r9,(PC_SLBSAVE+72)(%r1)
434	std	%r10,(PC_SLBSAVE+80)(%r1)
435	std	%r11,(PC_SLBSAVE+88)(%r1)
436	std	%r12,(PC_SLBSAVE+96)(%r1)
437	/* CR already saved */
438	mfxer	%r2			/* save XER */
439	std	%r2,(PC_SLBSAVE+112)(%r1)
440	mflr	%r2			/* save LR (SP already saved) */
441	std	%r2,(PC_SLBSAVE+120)(%r1)
442	mfctr	%r2			/* save CTR */
443	std	%r2,(PC_SLBSAVE+128)(%r1)
444
445	/* Call handler */
446	addi	%r1,%r1,PC_SLBSTACK-48+1024
447	li	%r2,~15
448	and	%r1,%r1,%r2
449	lis	%r3,tocbase@ha
450	ld	%r2,tocbase@l(%r3)
451	mflr	%r3
452	andi.	%r3,%r3,0xff80
453	mfdar	%r4
454	mfsrr0	%r5
455	bl	handle_kernel_slb_spill
456	nop
457
458	/* Save r28-31, restore r4-r12 */
459	GET_CPUINFO(%r1)
460	ld	%r4,(PC_SLBSAVE+32)(%r1)
461	ld	%r5,(PC_SLBSAVE+40)(%r1)
462	ld	%r6,(PC_SLBSAVE+48)(%r1)
463	ld	%r7,(PC_SLBSAVE+56)(%r1)
464	ld	%r8,(PC_SLBSAVE+64)(%r1)
465	ld	%r9,(PC_SLBSAVE+72)(%r1)
466	ld	%r10,(PC_SLBSAVE+80)(%r1)
467	ld	%r11,(PC_SLBSAVE+88)(%r1)
468	ld	%r12,(PC_SLBSAVE+96)(%r1)
469	std	%r28,(PC_SLBSAVE+64)(%r1)
470	std	%r29,(PC_SLBSAVE+72)(%r1)
471	std	%r30,(PC_SLBSAVE+80)(%r1)
472	std	%r31,(PC_SLBSAVE+88)(%r1)
473
474	/* Restore kernel mapping */
475	bl	restore_kernsrs
476
477	/* Restore remaining registers */
478	ld	%r28,(PC_SLBSAVE+64)(%r1)
479	ld	%r29,(PC_SLBSAVE+72)(%r1)
480	ld	%r30,(PC_SLBSAVE+80)(%r1)
481	ld	%r31,(PC_SLBSAVE+88)(%r1)
482
483	ld	%r2,(PC_SLBSAVE+104)(%r1)
484	mtcr	%r2
485	ld	%r2,(PC_SLBSAVE+112)(%r1)
486	mtxer	%r2
487	ld	%r2,(PC_SLBSAVE+120)(%r1)
488	mtlr	%r2
489	ld	%r2,(PC_SLBSAVE+128)(%r1)
490	mtctr	%r2
491	ld	%r2,(PC_SLBSAVE+136)(%r1)
492	mtlr	%r2
493
494	/* Restore r0-r3 */
495	ld	%r0,(PC_SLBSAVE+0)(%r1)
496	ld	%r2,(PC_SLBSAVE+16)(%r1)
497	ld	%r3,(PC_SLBSAVE+24)(%r1)
498	mfsprg1	%r1
499
500	/* Back to whatever we were doing */
501	rfid
502
503/*
504 * For ALI: has to save DSISR and DAR
505 */
506	.globl	CNAME(alitrap),CNAME(alisize)
507CNAME(alitrap):
508	mtsprg1	%r1			/* save SP */
509	GET_CPUINFO(%r1)
510	std	%r27,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)	/* free r27-r31 */
511	std	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
512	std	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
513	std	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
514	std	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
515	mfdar	%r30
516	mfdsisr	%r31
517	std	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
518	std	%r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
519	mfsprg1	%r1			/* restore SP, in case of branch */
520	mflr	%r28			/* save LR */
521	mfcr	%r29			/* save CR */
522
523	/* Put our exception vector in SPRG3 */
524	li	%r31, EXC_ALI
525	mtsprg3	%r31
526
527	/* Test whether we already had PR set */
528	mfsrr1	%r31
529	mtcr	%r31
530	bla	s_trap
531CNAME(alisize) = .-CNAME(alitrap)
532
533/*
534 * Similar to the above for DSI
535 * Has to handle BAT spills
536 * and standard pagetable spills
537 */
538	.globl	CNAME(dsitrap),CNAME(dsisize)
539CNAME(dsitrap):
540	mtsprg1	%r1			/* save SP */
541	GET_CPUINFO(%r1)
542	std	%r27,(PC_DISISAVE+CPUSAVE_R27)(%r1)	/* free r27-r31 */
543	std	%r28,(PC_DISISAVE+CPUSAVE_R28)(%r1)
544	std	%r29,(PC_DISISAVE+CPUSAVE_R29)(%r1)
545	std	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
546	std	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
547	mfsprg1	%r1			/* restore SP */
548	mfcr	%r29			/* save CR */
549	mfxer	%r30			/* save XER */
550	mtsprg2	%r30			/* in SPRG2 */
551	mfsrr1	%r31			/* test kernel mode */
552	mtcr	%r31
553	mflr	%r28			/* save LR (SP already saved) */
554	bla	disitrap
555CNAME(dsisize) = .-CNAME(dsitrap)
556
557/*
558 * Preamble code for DSI/ISI traps
559 */
560disitrap:
561	/* Write the trap vector to SPRG3 by computing LR & 0xff00 */
562	mflr	%r1
563	andi.	%r1,%r1,0xff00
564	mtsprg3	%r1
565
566	GET_CPUINFO(%r1)
567	ld	%r31,(PC_DISISAVE+CPUSAVE_R27)(%r1)
568	std	%r31,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)
569	ld	%r30,(PC_DISISAVE+CPUSAVE_R28)(%r1)
570	std	%r30,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
571	ld	%r31,(PC_DISISAVE+CPUSAVE_R29)(%r1)
572	std	%r31,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
573	ld	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
574	std	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
575	ld	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
576	std	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
577	mfdar	%r30
578	mfdsisr	%r31
579	std	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
580	std	%r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
581
582#ifdef KDB
583	/* Try to detect a kernel stack overflow */
584	mfsrr1	%r31
585	mtcr	%r31
586	bt	17,realtrap		/* branch is user mode */
587	mfsprg1	%r31			/* get old SP */
588	clrrdi	%r31,%r31,12		/* Round SP down to nearest page */
589	sub.	%r30,%r31,%r30		/* SP - DAR */
590	bge	1f
591	neg	%r30,%r30		/* modulo value */
5921:	cmpldi	%cr0,%r30,4096		/* is DAR within a page of SP? */
593	bge	%cr0,realtrap		/* no, too far away. */
594
595	/* Now convert this DSI into a DDB trap.  */
596	GET_CPUINFO(%r1)
597	ld	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1) /* get DAR */
598	std	%r30,(PC_DBSAVE  +CPUSAVE_AIM_DAR)(%r1) /* save DAR */
599	ld	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1) /* get DSISR */
600	std	%r30,(PC_DBSAVE  +CPUSAVE_AIM_DSISR)(%r1) /* save DSISR */
601	ld	%r31,(PC_DISISAVE+CPUSAVE_R27)(%r1) /* get  r27 */
602	std	%r31,(PC_DBSAVE  +CPUSAVE_R27)(%r1) /* save r27 */
603	ld	%r30,(PC_DISISAVE+CPUSAVE_R28)(%r1) /* get  r28 */
604	std	%r30,(PC_DBSAVE  +CPUSAVE_R28)(%r1) /* save r28 */
605	ld	%r31,(PC_DISISAVE+CPUSAVE_R29)(%r1) /* get  r29 */
606	std	%r31,(PC_DBSAVE  +CPUSAVE_R29)(%r1) /* save r29 */
607	ld	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1) /* get  r30 */
608	std	%r30,(PC_DBSAVE  +CPUSAVE_R30)(%r1) /* save r30 */
609	ld	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1) /* get  r31 */
610	std	%r31,(PC_DBSAVE  +CPUSAVE_R31)(%r1) /* save r31 */
611	b	dbtrap
612#endif
613
614	/* XXX need stack probe here */
615realtrap:
616/* Test whether we already had PR set */
617	mfsrr1	%r1
618	mtcr	%r1
619	mfsprg1	%r1			/* restore SP (might have been
620					   overwritten) */
621	bf	17,k_trap		/* branch if PSL_PR is false */
622	GET_CPUINFO(%r1)
623	ld	%r1,PC_CURPCB(%r1)
624	mr	%r27,%r28		/* Save LR, r29 */
625	mtsprg2	%r29
626	bl	restore_kernsrs		/* enable kernel mapping */
627	mfsprg2	%r29
628	mr	%r28,%r27
629	ba s_trap
630
631/*
632 * generictrap does some standard setup for trap handling to minimize
633 * the code that need be installed in the actual vectors. It expects
634 * the following conditions.
635 *
636 * R1 - Trap vector = LR & (0xff00 | R1)
637 * SPRG1 - Original R1 contents
638 * SPRG2 - Original LR
639 */
640
641generictrap:
642	/* Save R1 for computing the exception vector */
643	mtsprg3 %r1
644
645	/* Save interesting registers */
646	GET_CPUINFO(%r1)
647	std	%r27,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)	/* free r27-r31 */
648	std	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
649	std	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
650	std	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
651	std	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
652	mfdar	%r30
653	std	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
654	mfsprg1	%r1			/* restore SP, in case of branch */
655	mfsprg2	%r28			/* save LR */
656	mfcr	%r29			/* save CR */
657
658	/* Compute the exception vector from the link register */
659	mfsprg3 %r31
660	ori	%r31,%r31,0xff00
661	mflr	%r30
662	and	%r30,%r30,%r31
663	mtsprg3	%r30
664
665	/* Test whether we already had PR set */
666	mfsrr1	%r31
667	mtcr	%r31
668
669s_trap:
670	bf	17,k_trap		/* branch if PSL_PR is false */
671	GET_CPUINFO(%r1)
672u_trap:
673	ld	%r1,PC_CURPCB(%r1)
674	mr	%r27,%r28		/* Save LR, r29 */
675	mtsprg2	%r29
676	bl	restore_kernsrs		/* enable kernel mapping */
677	mfsprg2	%r29
678	mr	%r28,%r27
679
680/*
681 * Now the common trap catching code.
682 */
683k_trap:
684	FRAME_SETUP(PC_TEMPSAVE)
685/* Call C interrupt dispatcher: */
686trapagain:
687	lis	%r3,tocbase@ha
688	ld	%r2,tocbase@l(%r3)
689	addi	%r3,%r1,48
690	bl	CNAME(powerpc_interrupt)
691	nop
692
693	.globl	CNAME(trapexit)	/* backtrace code sentinel */
694CNAME(trapexit):
695/* Disable interrupts: */
696	mfmsr	%r3
697	andi.	%r3,%r3,~PSL_EE@l
698	mtmsr	%r3
699	isync
700/* Test AST pending: */
701	ld	%r5,FRAME_SRR1+48(%r1)
702	mtcr	%r5
703	bf	17,1f			/* branch if PSL_PR is false */
704
705	GET_CPUINFO(%r3)		/* get per-CPU pointer */
706	lwz	%r4, TD_FLAGS(%r13)	/* get thread flags value */
707	lis	%r5, (TDF_ASTPENDING|TDF_NEEDRESCHED)@h
708	ori	%r5,%r5, (TDF_ASTPENDING|TDF_NEEDRESCHED)@l
709	and.	%r4,%r4,%r5
710	beq	1f
711	mfmsr	%r3			/* re-enable interrupts */
712	ori	%r3,%r3,PSL_EE@l
713	mtmsr	%r3
714	isync
715	lis	%r3,tocbase@ha
716	ld	%r2,tocbase@l(%r3)
717	addi	%r3,%r1,48
718	bl	CNAME(ast)
719	nop
720	.globl	CNAME(asttrapexit)	/* backtrace code sentinel #2 */
721CNAME(asttrapexit):
722	b	trapexit		/* test ast ret value ? */
7231:
724	FRAME_LEAVE(PC_TEMPSAVE)
725	rfid
726
727#if defined(KDB)
728/*
729 * Deliberate entry to dbtrap
730 */
731ASENTRY_NOPROF(breakpoint)
732	mtsprg1	%r1
733	mfmsr	%r3
734	mtsrr1	%r3
735	andi.	%r3,%r3,~(PSL_EE|PSL_ME)@l
736	mtmsr	%r3			/* disable interrupts */
737	isync
738	GET_CPUINFO(%r3)
739	std	%r27,(PC_DBSAVE+CPUSAVE_R27)(%r3)
740	std	%r28,(PC_DBSAVE+CPUSAVE_R28)(%r3)
741	std	%r29,(PC_DBSAVE+CPUSAVE_R29)(%r3)
742	std	%r30,(PC_DBSAVE+CPUSAVE_R30)(%r3)
743	std	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r3)
744	mflr	%r28
745	li	%r29,EXC_BPT
746	mtlr	%r29
747	mfcr	%r29
748	mtsrr0	%r28
749
750/*
751 * Now the kdb trap catching code.
752 */
753dbtrap:
754	/* Write the trap vector to SPRG3 by computing LR & 0xff00 */
755	mflr	%r1
756	andi.	%r1,%r1,0xff00
757	mtsprg3	%r1
758
759	lis	%r1,(tmpstk+TMPSTKSZ-48)@ha	/* get new SP */
760	addi	%r1,%r1,(tmpstk+TMPSTKSZ-48)@l
761
762	FRAME_SETUP(PC_DBSAVE)
763/* Call C trap code: */
764	lis	%r3,tocbase@ha
765	ld	%r2,tocbase@l(%r3)
766	addi	%r3,%r1,48
767	bl	CNAME(db_trap_glue)
768	nop
769	or.	%r3,%r3,%r3
770	bne	dbleave
771/* This wasn't for KDB, so switch to real trap: */
772	ld	%r3,FRAME_EXC+48(%r1)	/* save exception */
773	GET_CPUINFO(%r4)
774	std	%r3,(PC_DBSAVE+CPUSAVE_R31)(%r4)
775	FRAME_LEAVE(PC_DBSAVE)
776	mtsprg1	%r1			/* prepare for entrance to realtrap */
777	GET_CPUINFO(%r1)
778	std	%r27,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)
779	std	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
780	std	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
781	std	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
782	std	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
783	mflr	%r28
784	mfcr	%r29
785	ld	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r1)
786	mtsprg3	%r31			/* SPRG3 was clobbered by FRAME_LEAVE */
787	mfsprg1	%r1
788	b	realtrap
789dbleave:
790	FRAME_LEAVE(PC_DBSAVE)
791	rfid
792
793/*
794 * In case of KDB we want a separate trap catcher for it
795 */
796	.globl	CNAME(dblow),CNAME(dbsize)
797CNAME(dblow):
798	mtsprg1	%r1			/* save SP */
799	mtsprg2	%r29			/* save r29 */
800	mfcr	%r29			/* save CR in r29 */
801	mfsrr1	%r1
802	mtcr	%r1
803	bf	17,2f			/* branch if privileged */
804
8051:
806	/* Unprivileged case */
807	mtcr	%r29			/* put the condition register back */
808        mfsprg2	%r29			/* ... and r29 */
809        mflr	%r1			/* save LR */
810	mtsprg2 %r1			/* And then in SPRG2 */
811	li	%r1, 0	 		/* How to get the vector from LR */
812
813        bla     generictrap		/* and we look like a generic trap */
8142:
815#ifdef KDTRACE_HOOKS
816	/* Privileged, so drop to KDB */
817	mfsrr0	%r1
818	mtsprg3	%r3
819	lwz	%r1,0(%r1)
820	/* Check if it's a DTrace trap. */
821	li	%r3,0x0808
822	addis	%r3,%r3,0x7c81
823	cmplw	%cr0,%r3,%r1
824	mfsprg3	%r3
825	beq	%cr0,1b
826#endif
827	GET_CPUINFO(%r1)
828	std	%r27,(PC_DBSAVE+CPUSAVE_R27)(%r1)	/* free r27 */
829	std	%r28,(PC_DBSAVE+CPUSAVE_R28)(%r1)	/* free r28 */
830        mfsprg2	%r28				/* r29 holds cr...  */
831        std	%r28,(PC_DBSAVE+CPUSAVE_R29)(%r1)	/* free r29 */
832        std	%r30,(PC_DBSAVE+CPUSAVE_R30)(%r1)	/* free r30 */
833        std	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r1)	/* free r31 */
834        mflr	%r28					/* save LR */
835	bla	dbtrap
836CNAME(dbsize) = .-CNAME(dblow)
837#endif /* KDB */
838