xref: /freebsd/sys/powerpc/aim/trap_subr64.S (revision 545ddfbe7d4fe8adfb862903b24eac1d5896c1ef)
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	GET_TOCBASE(%r2)
311
312	ld	%r1,TOC_REF(tmpstk)(%r2)	/* get new SP */
313	addi	%r1,%r1,(TMPSTKSZ-48)
314
315	bl	CNAME(cpudep_ap_early_bootstrap) /* Set PCPU */
316	nop
317	lis	%r3,1@l
318	bl	CNAME(pmap_cpu_bootstrap)	/* Turn on virtual memory */
319	nop
320	bl	CNAME(cpudep_ap_bootstrap)	/* Set up PCPU and stack */
321	nop
322	mr	%r1,%r3				/* Use new stack */
323	bl	CNAME(cpudep_ap_setup)
324	nop
325	GET_CPUINFO(%r5)
326	ld	%r3,(PC_RESTORE)(%r5)
327	cmpldi	%cr0,%r3,0
328	beq	%cr0,2f
329	nop
330	li	%r4,1
331	b	CNAME(longjmp)
332	nop
3332:
334#ifdef SMP
335	bl	CNAME(machdep_ap_bootstrap)	/* And away! */
336	nop
337#endif
338
339	/* Should not be reached */
3409:
341	b	9b
342
343/*
344 * This code gets copied to all the trap vectors
345 * (except ISI/DSI, ALI, and the interrupts)
346 */
347
348	.globl	CNAME(trapcode),CNAME(trapsize)
349CNAME(trapcode):
350	mtsprg1	%r1			/* save SP */
351	mflr	%r1			/* Save the old LR in r1 */
352	mtsprg2 %r1			/* And then in SPRG2 */
353	li	%r1, 0xA0		/* How to get the vector from LR */
354	bla	generictrap		/* LR & SPRG3 is exception # */
355CNAME(trapsize) = .-CNAME(trapcode)
356
357/*
358 * For SLB misses: do special things for the kernel
359 *
360 * Note: SPRG1 is always safe to overwrite any time the MMU is on, which is
361 * the only time this can be called.
362 */
363	.globl	CNAME(slbtrap),CNAME(slbtrapsize)
364CNAME(slbtrap):
365	mtsprg1	%r1			/* save SP */
366	GET_CPUINFO(%r1)
367	std	%r2,(PC_SLBSAVE+16)(%r1)
368	mfcr	%r2			/* save CR */
369	std	%r2,(PC_SLBSAVE+104)(%r1)
370	mfsrr1	%r2			/* test kernel mode */
371	mtcr	%r2
372	bf	17,1f			/* branch if PSL_PR is false */
373	/* User mode */
374	ld	%r2,(PC_SLBSAVE+104)(%r1) /* Restore CR */
375	mtcr	%r2
376	ld	%r2,(PC_SLBSAVE+16)(%r1) /* Restore R2 */
377	mflr	%r1			/* Save the old LR in r1 */
378	mtsprg2 %r1			/* And then in SPRG2 */
379	li	%r1, 0x80		/* How to get the vector from LR */
380	bla	generictrap		/* LR & SPRG3 is exception # */
3811:	mflr	%r2			/* Save the old LR in r2 */
382	bla	kern_slbtrap
383CNAME(slbtrapsize) = .-CNAME(slbtrap)
384
385kern_slbtrap:
386	std	%r2,(PC_SLBSAVE+136)(%r1) /* old LR */
387	std	%r3,(PC_SLBSAVE+24)(%r1) /* save R3 */
388
389	/* Check if this needs to be handled as a regular trap (userseg miss) */
390	mflr	%r2
391	andi.	%r2,%r2,0xff80
392	cmpwi	%r2,0x380
393	bne	1f
394	mfdar	%r2
395	b	2f
3961:	mfsrr0	%r2
3972:	/* r2 now contains the fault address */
398	lis	%r3,SEGMENT_MASK@highesta
399	ori	%r3,%r3,SEGMENT_MASK@highera
400	sldi	%r3,%r3,32
401	oris	%r3,%r3,SEGMENT_MASK@ha
402	ori	%r3,%r3,SEGMENT_MASK@l
403	and	%r2,%r2,%r3	/* R2 = segment base address */
404	lis	%r3,USER_ADDR@highesta
405	ori	%r3,%r3,USER_ADDR@highera
406	sldi	%r3,%r3,32
407	oris	%r3,%r3,USER_ADDR@ha
408	ori	%r3,%r3,USER_ADDR@l
409	cmpd	%r2,%r3		/* Compare fault base to USER_ADDR */
410	bne	3f
411
412	/* User seg miss, handle as a regular trap */
413	ld	%r2,(PC_SLBSAVE+104)(%r1) /* Restore CR */
414	mtcr	%r2
415	ld	%r2,(PC_SLBSAVE+16)(%r1) /* Restore R2,R3 */
416	ld	%r3,(PC_SLBSAVE+24)(%r1)
417	ld	%r1,(PC_SLBSAVE+136)(%r1) /* Save the old LR in r1 */
418	mtsprg2 %r1			/* And then in SPRG2 */
419	li	%r1, 0x80		/* How to get the vector from LR */
420	b	generictrap		/* Retain old LR using b */
421
4223:	/* Real kernel SLB miss */
423	std	%r0,(PC_SLBSAVE+0)(%r1)	/* free all volatile regs */
424	mfsprg1	%r2			/* Old R1 */
425	std	%r2,(PC_SLBSAVE+8)(%r1)
426	/* R2,R3 already saved */
427	std	%r4,(PC_SLBSAVE+32)(%r1)
428	std	%r5,(PC_SLBSAVE+40)(%r1)
429	std	%r6,(PC_SLBSAVE+48)(%r1)
430	std	%r7,(PC_SLBSAVE+56)(%r1)
431	std	%r8,(PC_SLBSAVE+64)(%r1)
432	std	%r9,(PC_SLBSAVE+72)(%r1)
433	std	%r10,(PC_SLBSAVE+80)(%r1)
434	std	%r11,(PC_SLBSAVE+88)(%r1)
435	std	%r12,(PC_SLBSAVE+96)(%r1)
436	/* CR already saved */
437	mfxer	%r2			/* save XER */
438	std	%r2,(PC_SLBSAVE+112)(%r1)
439	mflr	%r2			/* save LR (SP already saved) */
440	std	%r2,(PC_SLBSAVE+120)(%r1)
441	mfctr	%r2			/* save CTR */
442	std	%r2,(PC_SLBSAVE+128)(%r1)
443
444	/* Call handler */
445	addi	%r1,%r1,PC_SLBSTACK-48+1024
446	li	%r2,~15
447	and	%r1,%r1,%r2
448	GET_TOCBASE(%r2)
449	mflr	%r3
450	andi.	%r3,%r3,0xff80
451	mfdar	%r4
452	mfsrr0	%r5
453	bl	handle_kernel_slb_spill
454	nop
455
456	/* Save r28-31, restore r4-r12 */
457	GET_CPUINFO(%r1)
458	ld	%r4,(PC_SLBSAVE+32)(%r1)
459	ld	%r5,(PC_SLBSAVE+40)(%r1)
460	ld	%r6,(PC_SLBSAVE+48)(%r1)
461	ld	%r7,(PC_SLBSAVE+56)(%r1)
462	ld	%r8,(PC_SLBSAVE+64)(%r1)
463	ld	%r9,(PC_SLBSAVE+72)(%r1)
464	ld	%r10,(PC_SLBSAVE+80)(%r1)
465	ld	%r11,(PC_SLBSAVE+88)(%r1)
466	ld	%r12,(PC_SLBSAVE+96)(%r1)
467	std	%r28,(PC_SLBSAVE+64)(%r1)
468	std	%r29,(PC_SLBSAVE+72)(%r1)
469	std	%r30,(PC_SLBSAVE+80)(%r1)
470	std	%r31,(PC_SLBSAVE+88)(%r1)
471
472	/* Restore kernel mapping */
473	bl	restore_kernsrs
474
475	/* Restore remaining registers */
476	ld	%r28,(PC_SLBSAVE+64)(%r1)
477	ld	%r29,(PC_SLBSAVE+72)(%r1)
478	ld	%r30,(PC_SLBSAVE+80)(%r1)
479	ld	%r31,(PC_SLBSAVE+88)(%r1)
480
481	ld	%r2,(PC_SLBSAVE+104)(%r1)
482	mtcr	%r2
483	ld	%r2,(PC_SLBSAVE+112)(%r1)
484	mtxer	%r2
485	ld	%r2,(PC_SLBSAVE+120)(%r1)
486	mtlr	%r2
487	ld	%r2,(PC_SLBSAVE+128)(%r1)
488	mtctr	%r2
489	ld	%r2,(PC_SLBSAVE+136)(%r1)
490	mtlr	%r2
491
492	/* Restore r0-r3 */
493	ld	%r0,(PC_SLBSAVE+0)(%r1)
494	ld	%r2,(PC_SLBSAVE+16)(%r1)
495	ld	%r3,(PC_SLBSAVE+24)(%r1)
496	mfsprg1	%r1
497
498	/* Back to whatever we were doing */
499	rfid
500
501/*
502 * For ALI: has to save DSISR and DAR
503 */
504	.globl	CNAME(alitrap),CNAME(alisize)
505CNAME(alitrap):
506	mtsprg1	%r1			/* save SP */
507	GET_CPUINFO(%r1)
508	std	%r27,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)	/* free r27-r31 */
509	std	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
510	std	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
511	std	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
512	std	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
513	mfdar	%r30
514	mfdsisr	%r31
515	std	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
516	std	%r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
517	mfsprg1	%r1			/* restore SP, in case of branch */
518	mflr	%r28			/* save LR */
519	mfcr	%r29			/* save CR */
520
521	/* Put our exception vector in SPRG3 */
522	li	%r31, EXC_ALI
523	mtsprg3	%r31
524
525	/* Test whether we already had PR set */
526	mfsrr1	%r31
527	mtcr	%r31
528	bla	s_trap
529CNAME(alisize) = .-CNAME(alitrap)
530
531/*
532 * Similar to the above for DSI
533 * Has to handle BAT spills
534 * and standard pagetable spills
535 */
536	.globl	CNAME(dsitrap),CNAME(dsisize)
537CNAME(dsitrap):
538	mtsprg1	%r1			/* save SP */
539	GET_CPUINFO(%r1)
540	std	%r27,(PC_DISISAVE+CPUSAVE_R27)(%r1)	/* free r27-r31 */
541	std	%r28,(PC_DISISAVE+CPUSAVE_R28)(%r1)
542	std	%r29,(PC_DISISAVE+CPUSAVE_R29)(%r1)
543	std	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
544	std	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
545	mfsprg1	%r1			/* restore SP */
546	mfcr	%r29			/* save CR */
547	mfxer	%r30			/* save XER */
548	mtsprg2	%r30			/* in SPRG2 */
549	mfsrr1	%r31			/* test kernel mode */
550	mtcr	%r31
551	mflr	%r28			/* save LR (SP already saved) */
552	bla	disitrap
553CNAME(dsisize) = .-CNAME(dsitrap)
554
555/*
556 * Preamble code for DSI/ISI traps
557 */
558disitrap:
559	/* Write the trap vector to SPRG3 by computing LR & 0xff00 */
560	mflr	%r1
561	andi.	%r1,%r1,0xff00
562	mtsprg3	%r1
563
564	GET_CPUINFO(%r1)
565	ld	%r31,(PC_DISISAVE+CPUSAVE_R27)(%r1)
566	std	%r31,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)
567	ld	%r30,(PC_DISISAVE+CPUSAVE_R28)(%r1)
568	std	%r30,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
569	ld	%r31,(PC_DISISAVE+CPUSAVE_R29)(%r1)
570	std	%r31,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
571	ld	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
572	std	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
573	ld	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
574	std	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
575	mfdar	%r30
576	mfdsisr	%r31
577	std	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
578	std	%r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
579
580#ifdef KDB
581	/* Try to detect a kernel stack overflow */
582	mfsrr1	%r31
583	mtcr	%r31
584	bt	17,realtrap		/* branch is user mode */
585	mfsprg1	%r31			/* get old SP */
586	clrrdi	%r31,%r31,12		/* Round SP down to nearest page */
587	sub.	%r30,%r31,%r30		/* SP - DAR */
588	bge	1f
589	neg	%r30,%r30		/* modulo value */
5901:	cmpldi	%cr0,%r30,4096		/* is DAR within a page of SP? */
591	bge	%cr0,realtrap		/* no, too far away. */
592
593	/* Now convert this DSI into a DDB trap.  */
594	GET_CPUINFO(%r1)
595	ld	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1) /* get DAR */
596	std	%r30,(PC_DBSAVE  +CPUSAVE_AIM_DAR)(%r1) /* save DAR */
597	ld	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1) /* get DSISR */
598	std	%r30,(PC_DBSAVE  +CPUSAVE_AIM_DSISR)(%r1) /* save DSISR */
599	ld	%r31,(PC_DISISAVE+CPUSAVE_R27)(%r1) /* get  r27 */
600	std	%r31,(PC_DBSAVE  +CPUSAVE_R27)(%r1) /* save r27 */
601	ld	%r30,(PC_DISISAVE+CPUSAVE_R28)(%r1) /* get  r28 */
602	std	%r30,(PC_DBSAVE  +CPUSAVE_R28)(%r1) /* save r28 */
603	ld	%r31,(PC_DISISAVE+CPUSAVE_R29)(%r1) /* get  r29 */
604	std	%r31,(PC_DBSAVE  +CPUSAVE_R29)(%r1) /* save r29 */
605	ld	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1) /* get  r30 */
606	std	%r30,(PC_DBSAVE  +CPUSAVE_R30)(%r1) /* save r30 */
607	ld	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1) /* get  r31 */
608	std	%r31,(PC_DBSAVE  +CPUSAVE_R31)(%r1) /* save r31 */
609	b	dbtrap
610#endif
611
612	/* XXX need stack probe here */
613realtrap:
614/* Test whether we already had PR set */
615	mfsrr1	%r1
616	mtcr	%r1
617	mfsprg1	%r1			/* restore SP (might have been
618					   overwritten) */
619	bf	17,k_trap		/* branch if PSL_PR is false */
620	GET_CPUINFO(%r1)
621	ld	%r1,PC_CURPCB(%r1)
622	mr	%r27,%r28		/* Save LR, r29 */
623	mtsprg2	%r29
624	bl	restore_kernsrs		/* enable kernel mapping */
625	mfsprg2	%r29
626	mr	%r28,%r27
627	ba s_trap
628
629/*
630 * generictrap does some standard setup for trap handling to minimize
631 * the code that need be installed in the actual vectors. It expects
632 * the following conditions.
633 *
634 * R1 - Trap vector = LR & (0xff00 | R1)
635 * SPRG1 - Original R1 contents
636 * SPRG2 - Original LR
637 */
638
639generictrap:
640	/* Save R1 for computing the exception vector */
641	mtsprg3 %r1
642
643	/* Save interesting registers */
644	GET_CPUINFO(%r1)
645	std	%r27,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)	/* free r27-r31 */
646	std	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
647	std	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
648	std	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
649	std	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
650	mfdar	%r30
651	std	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
652	mfsprg1	%r1			/* restore SP, in case of branch */
653	mfsprg2	%r28			/* save LR */
654	mfcr	%r29			/* save CR */
655
656	/* Compute the exception vector from the link register */
657	mfsprg3 %r31
658	ori	%r31,%r31,0xff00
659	mflr	%r30
660	and	%r30,%r30,%r31
661	mtsprg3	%r30
662
663	/* Test whether we already had PR set */
664	mfsrr1	%r31
665	mtcr	%r31
666
667s_trap:
668	bf	17,k_trap		/* branch if PSL_PR is false */
669	GET_CPUINFO(%r1)
670u_trap:
671	ld	%r1,PC_CURPCB(%r1)
672	mr	%r27,%r28		/* Save LR, r29 */
673	mtsprg2	%r29
674	bl	restore_kernsrs		/* enable kernel mapping */
675	mfsprg2	%r29
676	mr	%r28,%r27
677
678/*
679 * Now the common trap catching code.
680 */
681k_trap:
682	FRAME_SETUP(PC_TEMPSAVE)
683/* Call C interrupt dispatcher: */
684trapagain:
685	GET_TOCBASE(%r2)
686	addi	%r3,%r1,48
687	bl	CNAME(powerpc_interrupt)
688	nop
689
690	.globl	CNAME(trapexit)	/* backtrace code sentinel */
691CNAME(trapexit):
692/* Disable interrupts: */
693	mfmsr	%r3
694	andi.	%r3,%r3,~PSL_EE@l
695	mtmsr	%r3
696	isync
697/* Test AST pending: */
698	ld	%r5,FRAME_SRR1+48(%r1)
699	mtcr	%r5
700	bf	17,1f			/* branch if PSL_PR is false */
701
702	GET_CPUINFO(%r3)		/* get per-CPU pointer */
703	lwz	%r4, TD_FLAGS(%r13)	/* get thread flags value */
704	lis	%r5, (TDF_ASTPENDING|TDF_NEEDRESCHED)@h
705	ori	%r5,%r5, (TDF_ASTPENDING|TDF_NEEDRESCHED)@l
706	and.	%r4,%r4,%r5
707	beq	1f
708	mfmsr	%r3			/* re-enable interrupts */
709	ori	%r3,%r3,PSL_EE@l
710	mtmsr	%r3
711	isync
712	GET_TOCBASE(%r2)
713	addi	%r3,%r1,48
714	bl	CNAME(ast)
715	nop
716	.globl	CNAME(asttrapexit)	/* backtrace code sentinel #2 */
717CNAME(asttrapexit):
718	b	trapexit		/* test ast ret value ? */
7191:
720	FRAME_LEAVE(PC_TEMPSAVE)
721	rfid
722
723#if defined(KDB)
724/*
725 * Deliberate entry to dbtrap
726 */
727ASENTRY_NOPROF(breakpoint)
728	mtsprg1	%r1
729	mfmsr	%r3
730	mtsrr1	%r3
731	andi.	%r3,%r3,~(PSL_EE|PSL_ME)@l
732	mtmsr	%r3			/* disable interrupts */
733	isync
734	GET_CPUINFO(%r3)
735	std	%r27,(PC_DBSAVE+CPUSAVE_R27)(%r3)
736	std	%r28,(PC_DBSAVE+CPUSAVE_R28)(%r3)
737	std	%r29,(PC_DBSAVE+CPUSAVE_R29)(%r3)
738	std	%r30,(PC_DBSAVE+CPUSAVE_R30)(%r3)
739	std	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r3)
740	mflr	%r28
741	li	%r29,EXC_BPT
742	mtlr	%r29
743	mfcr	%r29
744	mtsrr0	%r28
745
746/*
747 * Now the kdb trap catching code.
748 */
749dbtrap:
750	/* Write the trap vector to SPRG3 by computing LR & 0xff00 */
751	mflr	%r1
752	andi.	%r1,%r1,0xff00
753	mtsprg3	%r1
754
755	li	%r1,TRAP_TOCBASE		/* get new SP */
756	ld	%r1,0(%r1)
757	ld	%r1,TOC_REF(tmpstk)(%r1)
758	addi	%r1,%r1,(TMPSTKSZ-48)
759
760	FRAME_SETUP(PC_DBSAVE)
761/* Call C trap code: */
762	GET_TOCBASE(%r2)
763	addi	%r3,%r1,48
764	bl	CNAME(db_trap_glue)
765	nop
766	or.	%r3,%r3,%r3
767	bne	dbleave
768/* This wasn't for KDB, so switch to real trap: */
769	ld	%r3,FRAME_EXC+48(%r1)	/* save exception */
770	GET_CPUINFO(%r4)
771	std	%r3,(PC_DBSAVE+CPUSAVE_R31)(%r4)
772	FRAME_LEAVE(PC_DBSAVE)
773	mtsprg1	%r1			/* prepare for entrance to realtrap */
774	GET_CPUINFO(%r1)
775	std	%r27,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)
776	std	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
777	std	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
778	std	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
779	std	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
780	mflr	%r28
781	mfcr	%r29
782	ld	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r1)
783	mtsprg3	%r31			/* SPRG3 was clobbered by FRAME_LEAVE */
784	mfsprg1	%r1
785	b	realtrap
786dbleave:
787	FRAME_LEAVE(PC_DBSAVE)
788	rfid
789
790/*
791 * In case of KDB we want a separate trap catcher for it
792 */
793	.globl	CNAME(dblow),CNAME(dbsize)
794CNAME(dblow):
795	mtsprg1	%r1			/* save SP */
796	mtsprg2	%r29			/* save r29 */
797	mfcr	%r29			/* save CR in r29 */
798	mfsrr1	%r1
799	mtcr	%r1
800	bf	17,1f			/* branch if privileged */
801
802	/* Unprivileged case */
803	mtcr	%r29			/* put the condition register back */
804        mfsprg2	%r29			/* ... and r29 */
805        mflr	%r1			/* save LR */
806	mtsprg2 %r1			/* And then in SPRG2 */
807	li	%r1, 0	 		/* How to get the vector from LR */
808
809        bla     generictrap		/* and we look like a generic trap */
8101:
811	GET_CPUINFO(%r1)
812	std	%r27,(PC_DBSAVE+CPUSAVE_R27)(%r1)	/* free r27 */
813	std	%r28,(PC_DBSAVE+CPUSAVE_R28)(%r1)	/* free r28 */
814        mfsprg2	%r28				/* r29 holds cr...  */
815        std	%r28,(PC_DBSAVE+CPUSAVE_R29)(%r1)	/* free r29 */
816        std	%r30,(PC_DBSAVE+CPUSAVE_R30)(%r1)	/* free r30 */
817        std	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r1)	/* free r31 */
818        mflr	%r28					/* save LR */
819	bla	dbtrap
820CNAME(dbsize) = .-CNAME(dblow)
821#endif /* KDB */
822