xref: /freebsd/sys/powerpc/aim/trap_subr64.S (revision d4eeb02986980bf33dd56c41ceb9fc5f180c0d47)
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/* Locate the per-CPU data structure */
43#define GET_CPUINFO(r)  \
44        mfsprg0  r
45#define GET_TOCBASE(r)  \
46	lis	r,DMAP_BASE_ADDRESS@highesta;	/* To real-mode alias/dmap */ \
47	sldi	r,r,32;							\
48	ori	r,r,TRAP_TOCBASE;	/* Magic address for TOC */	\
49	ld	r,0(r)
50
51/*
52 * Restore SRs for a pmap
53 *
54 * Requires that r28-r31 be scratch, with r28 initialized to the SLB cache
55 */
56
57/*
58 * User SRs are loaded through a pointer to the current pmap.
59 * PCPU already in %r3
60 */
61restore_usersrs:
62	ld	%r28,PC_USERSLB(%r3)
63	cmpdi	%r28, 0			/* If user SLB pointer NULL, exit */
64	beqlr
65
66	li	%r29, 0			/* Set the counter to zero */
67
68	slbia
69	slbmfee	%r31,%r29
70	clrrdi	%r31,%r31,28
71	slbie	%r31
721:	ld	%r31, 0(%r28)		/* Load SLB entry pointer */
73	cmpdi	%r31, 0			/* If NULL, stop */
74	beqlr
75
76	ld	%r30, 0(%r31)		/* Load SLBV */
77	ld	%r31, 8(%r31)		/* Load SLBE */
78	or	%r31, %r31, %r29	/*  Set SLBE slot */
79	slbmte	%r30, %r31		/* Install SLB entry */
80
81	addi	%r28, %r28, 8		/* Advance pointer */
82	addi	%r29, %r29, 1
83	b	1b			/* Repeat */
84
85/*
86 * Kernel SRs are loaded directly from the PCPU fields
87 * PCPU in %r1
88 */
89restore_kernsrs:
90	lwz	%r29, PC_FLAGS(%r1)
91	mtcr	%r29
92	btlr	0
93	addi	%r28,%r1,PC_KERNSLB
94	ld	%r29,16(%r28)		/* One past USER_SLB_SLOT */
95	cmpdi	%r29,0
96	beqlr				/* If first kernel entry is invalid,
97					 * SLBs not in use, so exit early */
98
99	/* Otherwise, set up SLBs */
100	li	%r29, 0			/* Set the counter to zero */
101
102	slbia
103	slbmfee	%r31,%r29
104	clrrdi	%r31,%r31,28
105	slbie	%r31
1061:	cmpdi	%r29, USER_SLB_SLOT	/* Skip the user slot */
107	beq-	2f
108
109	ld	%r31, 8(%r28)		/* Load SLBE */
110	cmpdi	%r31, 0			/* If SLBE is not valid, stop */
111	beqlr
112	ld	%r30, 0(%r28)		/* Load SLBV  */
113	slbmte	%r30, %r31		/* Install SLB entry */
114
1152:	addi	%r28, %r28, 16		/* Advance pointer */
116	addi	%r29, %r29, 1
117	cmpdi	%r29, 64		/* Repeat if we are not at the end */
118	blt	1b
119	blr
120
121/*
122 * FRAME_SETUP assumes:
123 *	SPRG1		SP (1)
124 * 	SPRG3		trap type
125 *	savearea	r27-r31,DAR,DSISR   (DAR & DSISR only for DSI traps)
126 *	r28		LR
127 *	r29		CR
128 *	r30		scratch
129 *	r31		scratch
130 *	r1		kernel stack
131 *	SRR0/1		as at start of trap
132 *
133 * NOTE: SPRG1 is never used while the MMU is on, making it safe to reuse
134 * in any real-mode fault handler, including those handling double faults.
135 */
136#define	FRAME_SETUP(savearea)						\
137/* Have to enable translation to allow access of kernel stack: */	\
138	GET_CPUINFO(%r31);						\
139	mfsrr0	%r30;							\
140	std	%r30,(savearea+CPUSAVE_SRR0)(%r31);	/* save SRR0 */	\
141	mfsrr1	%r30;							\
142	std	%r30,(savearea+CPUSAVE_SRR1)(%r31);	/* save SRR1 */	\
143	mfsprg1	%r31;			/* get saved SP (clears SPRG1) */ \
144	mfmsr	%r30;							\
145	ori	%r30,%r30,(PSL_DR|PSL_IR|PSL_RI)@l; /* relocation on */	\
146	mtmsr	%r30;			/* stack can now be accessed */	\
147	isync;								\
148	stdu	%r31,-(FRAMELEN+288)(%r1); /* save it in the callframe */ \
149	std	%r0, FRAME_0+48(%r1);	/* save r0 in the trapframe */	\
150	std	%r31,FRAME_1+48(%r1);	/* save SP   "      "       */	\
151	std	%r2, FRAME_2+48(%r1);	/* save r2   "      "       */	\
152	std	%r28,FRAME_LR+48(%r1);	/* save LR   "      "       */	\
153	std	%r29,FRAME_CR+48(%r1);	/* save CR   "      "       */	\
154	GET_CPUINFO(%r2);						\
155	ld	%r27,(savearea+CPUSAVE_R27)(%r2); /* get saved r27 */	\
156	ld	%r28,(savearea+CPUSAVE_R28)(%r2); /* get saved r28 */	\
157	ld	%r29,(savearea+CPUSAVE_R29)(%r2); /* get saved r29 */	\
158	ld	%r30,(savearea+CPUSAVE_R30)(%r2); /* get saved r30 */	\
159	ld	%r31,(savearea+CPUSAVE_R31)(%r2); /* get saved r31 */	\
160	std	%r3,  FRAME_3+48(%r1);	/* save r3-r31 */		\
161	std	%r4,  FRAME_4+48(%r1);					\
162	std	%r5,  FRAME_5+48(%r1);					\
163	std	%r6,  FRAME_6+48(%r1);					\
164	std	%r7,  FRAME_7+48(%r1);					\
165	std	%r8,  FRAME_8+48(%r1);					\
166	std	%r9,  FRAME_9+48(%r1);					\
167	std	%r10, FRAME_10+48(%r1);					\
168	std	%r11, FRAME_11+48(%r1);					\
169	std	%r12, FRAME_12+48(%r1);					\
170	std	%r13, FRAME_13+48(%r1);					\
171	std	%r14, FRAME_14+48(%r1);					\
172	std	%r15, FRAME_15+48(%r1);					\
173	std	%r16, FRAME_16+48(%r1);					\
174	std	%r17, FRAME_17+48(%r1);					\
175	std	%r18, FRAME_18+48(%r1);					\
176	std	%r19, FRAME_19+48(%r1);					\
177	std	%r20, FRAME_20+48(%r1);					\
178	std	%r21, FRAME_21+48(%r1);					\
179	std	%r22, FRAME_22+48(%r1);					\
180	std	%r23, FRAME_23+48(%r1);					\
181	std	%r24, FRAME_24+48(%r1);					\
182	std	%r25, FRAME_25+48(%r1);					\
183	std	%r26, FRAME_26+48(%r1);					\
184	std	%r27, FRAME_27+48(%r1);					\
185	std	%r28, FRAME_28+48(%r1);					\
186	std	%r29, FRAME_29+48(%r1);					\
187	std	%r30, FRAME_30+48(%r1);					\
188	std	%r31, FRAME_31+48(%r1);					\
189	ld	%r28,(savearea+CPUSAVE_AIM_DAR)(%r2);  /* saved DAR */	\
190	ld	%r29,(savearea+CPUSAVE_AIM_DSISR)(%r2);/* saved DSISR */\
191	ld	%r30,(savearea+CPUSAVE_SRR0)(%r2); /* saved SRR0 */	\
192	ld	%r31,(savearea+CPUSAVE_SRR1)(%r2); /* saved SRR1 */	\
193	mfxer	%r3;							\
194	mfctr	%r4;							\
195	mfsprg3	%r5;							\
196	std	%r3, FRAME_XER+48(1);	/* save xer/ctr/exc */		\
197	std	%r4, FRAME_CTR+48(1);					\
198	std	%r5, FRAME_EXC+48(1);					\
199	std	%r28,FRAME_AIM_DAR+48(1);				\
200	std	%r29,FRAME_AIM_DSISR+48(1); /* save dsisr/srr0/srr1 */	\
201	std	%r30,FRAME_SRR0+48(1);					\
202	std	%r31,FRAME_SRR1+48(1);					\
203	ld	%r13,PC_CURTHREAD(%r2)	/* set kernel curthread */
204
205#define	FRAME_LEAVE(savearea)						\
206/* Disable exceptions: */						\
207	mfmsr	%r2;							\
208	andi.	%r2,%r2,~PSL_EE@l;					\
209	mtmsr	%r2;							\
210	isync;								\
211/* Now restore regs: */							\
212	ld	%r2,FRAME_SRR0+48(%r1);					\
213	ld	%r3,FRAME_SRR1+48(%r1);					\
214	ld	%r4,FRAME_CTR+48(%r1);					\
215	ld	%r5,FRAME_XER+48(%r1);					\
216	ld	%r6,FRAME_LR+48(%r1);					\
217	GET_CPUINFO(%r7);						\
218	std	%r2,(savearea+CPUSAVE_SRR0)(%r7); /* save SRR0 */	\
219	std	%r3,(savearea+CPUSAVE_SRR1)(%r7); /* save SRR1 */	\
220	ld	%r7,FRAME_CR+48(%r1);					\
221	mtctr	%r4;							\
222	mtxer	%r5;							\
223	mtlr	%r6;							\
224	mtsprg2	%r7;			/* save cr */			\
225	ld	%r31,FRAME_31+48(%r1);   /* restore r0-31 */		\
226	ld	%r30,FRAME_30+48(%r1);					\
227	ld	%r29,FRAME_29+48(%r1);					\
228	ld	%r28,FRAME_28+48(%r1);					\
229	ld	%r27,FRAME_27+48(%r1);					\
230	ld	%r26,FRAME_26+48(%r1);					\
231	ld	%r25,FRAME_25+48(%r1);					\
232	ld	%r24,FRAME_24+48(%r1);					\
233	ld	%r23,FRAME_23+48(%r1);					\
234	ld	%r22,FRAME_22+48(%r1);					\
235	ld	%r21,FRAME_21+48(%r1);					\
236	ld	%r20,FRAME_20+48(%r1);					\
237	ld	%r19,FRAME_19+48(%r1);					\
238	ld	%r18,FRAME_18+48(%r1);					\
239	ld	%r17,FRAME_17+48(%r1);					\
240	ld	%r16,FRAME_16+48(%r1);					\
241	ld	%r15,FRAME_15+48(%r1);					\
242	ld	%r14,FRAME_14+48(%r1);					\
243	ld	%r13,FRAME_13+48(%r1);					\
244	ld	%r12,FRAME_12+48(%r1);					\
245	ld	%r11,FRAME_11+48(%r1);					\
246	ld	%r10,FRAME_10+48(%r1);					\
247	ld	%r9, FRAME_9+48(%r1);					\
248	ld	%r8, FRAME_8+48(%r1);					\
249	ld	%r7, FRAME_7+48(%r1);					\
250	ld	%r6, FRAME_6+48(%r1);					\
251	ld	%r5, FRAME_5+48(%r1);					\
252	ld	%r4, FRAME_4+48(%r1);					\
253	ld	%r3, FRAME_3+48(%r1);					\
254	ld	%r2, FRAME_2+48(%r1);					\
255	ld	%r0, FRAME_0+48(%r1);					\
256	ld	%r1, FRAME_1+48(%r1);					\
257/* Can't touch %r1 from here on */					\
258	mtsprg3	%r3;			/* save r3 */			\
259/* Disable translation, machine check and recoverability: */		\
260	mfmsr	%r3;							\
261	andi.	%r3,%r3,~(PSL_DR|PSL_IR|PSL_ME|PSL_RI)@l;		\
262	mtmsr	%r3;							\
263	isync;								\
264/* Decide whether we return to user mode: */				\
265	GET_CPUINFO(%r3);						\
266	ld	%r3,(savearea+CPUSAVE_SRR1)(%r3);			\
267	mtcr	%r3;							\
268	bf	17,1f;			/* branch if PSL_PR is false */	\
269/* Restore user SRs */							\
270	GET_CPUINFO(%r3);						\
271	std	%r27,(savearea+CPUSAVE_R27)(%r3);			\
272	lwz	%r27,PC_FLAGS(%r3);					\
273	mtcr	%r27;							\
274	bt	0, 0f;	/* Check to skip restoring SRs. */		\
275	std	%r28,(savearea+CPUSAVE_R28)(%r3);			\
276	std	%r29,(savearea+CPUSAVE_R29)(%r3);			\
277	std	%r30,(savearea+CPUSAVE_R30)(%r3);			\
278	std	%r31,(savearea+CPUSAVE_R31)(%r3);			\
279	mflr	%r27;			/* preserve LR */		\
280	bl	restore_usersrs;	/* uses r28-r31 */		\
281	mtlr	%r27;							\
282	ld	%r31,(savearea+CPUSAVE_R31)(%r3);			\
283	ld	%r30,(savearea+CPUSAVE_R30)(%r3);			\
284	ld	%r29,(savearea+CPUSAVE_R29)(%r3);			\
285	ld	%r28,(savearea+CPUSAVE_R28)(%r3);			\
2860:									\
287	ld	%r27,(savearea+CPUSAVE_R27)(%r3);			\
2881:	mfsprg2	%r3;			/* restore cr */		\
289	mtcr	%r3;							\
290	GET_CPUINFO(%r3);						\
291	ld	%r3,(savearea+CPUSAVE_SRR0)(%r3); /* restore srr0 */	\
292	mtsrr0	%r3;							\
293	GET_CPUINFO(%r3);						\
294	ld	%r3,(savearea+CPUSAVE_SRR1)(%r3); /* restore srr1 */	\
295	mtsrr1	%r3;							\
296	mfsprg3	%r3			/* restore r3 */
297
298#ifdef KDTRACE_HOOKS
299	.data
300	.globl	dtrace_invop_calltrap_addr
301	.align	8
302	.type	dtrace_invop_calltrap_addr, @object
303        .size	dtrace_invop_calltrap_addr, 8
304dtrace_invop_calltrap_addr:
305	.word	0
306	.word	0
307
308	.text
309#endif
310
311/*
312 * Processor reset exception handler. These are typically
313 * the first instructions the processor executes after a
314 * software reset. We do this in two bits so that we are
315 * not still hanging around in the trap handling region
316 * once the MMU is turned on.
317 */
318	.globl	CNAME(rstcode), CNAME(rstcodeend), CNAME(cpu_reset_handler)
319	.globl	CNAME(cpu_wakeup_handler)
320	.p2align 3
321CNAME(rstcode):
322#ifdef __LITTLE_ENDIAN__
323	/*
324	 * XXX This shouldn't be necessary.
325	 *
326	 * According to the ISA documentation, LE should be set from HILE
327	 * or the LPCR ILE bit automatically. However, the entry into this
328	 * vector from OPAL_START_CPU does not honor this correctly.
329	 *
330	 * We should be able to define an alternate entry for opal's
331	 * start_kernel_secondary asm code to branch to.
332	 */
333	RETURN_TO_NATIVE_ENDIAN
334#endif
335	/*
336	 * Check if this is software reset or
337	 * processor is waking up from power saving mode
338	 * It is software reset when 46:47 = 0b00
339	 */
340	/* 0x00 */
341	ld	%r2,TRAP_GENTRAP(0)	/* Real-mode &generictrap */
342	mfsrr1	%r9			/* Load SRR1 into r9 */
343	andis.	%r9,%r9,0x3		/* Logic AND with 46:47 bits */
344
345	beq	2f			/* Branch if software reset */
346	/* 0x10 */
347	/* Reset was wakeup */
348	addi	%r9,%r2,(cpu_wakeup_handler-generictrap)
349	b	1f			/* Was power save, do the wakeup */
350
351	/* Reset was software reset */
352	/* Explicitly set MSR[SF] */
3532:	mfmsr	%r9
354	li	%r8,1
355	/* 0x20 */
356	insrdi	%r9,%r8,1,0
357	mtmsrd	%r9
358	isync
359
360	addi	%r9,%r2,(cpu_reset_handler-generictrap)
361
362	/* 0x30 */
3631:	mtlr	%r9
364	blr				/* Branch to either cpu_reset_handler
365					 * or cpu_wakeup_handler.
366					 */
367CNAME(rstcodeend):
368
369cpu_reset_handler:
370	GET_TOCBASE(%r2)
371
372	addis	%r1,%r2,TOC_REF(tmpstk)@ha
373	ld	%r1,TOC_REF(tmpstk)@l(%r1)	/* get new SP */
374	addi	%r1,%r1,(TMPSTKSZ-48)
375
376	bl	CNAME(cpudep_ap_early_bootstrap) /* Set PCPU */
377	nop
378	lis	%r3,1@l
379	bl	CNAME(pmap_cpu_bootstrap)	/* Turn on virtual memory */
380	nop
381	bl	CNAME(cpudep_ap_bootstrap)	/* Set up PCPU and stack */
382	nop
383	mr	%r1,%r3				/* Use new stack */
384	bl	CNAME(cpudep_ap_setup)
385	nop
386	GET_CPUINFO(%r5)
387	ld	%r3,(PC_RESTORE)(%r5)
388	cmpldi	%cr0,%r3,0
389	beq	%cr0,2f
390	nop
391	li	%r4,1
392	bl	CNAME(longjmp)
393	nop
3942:
395#ifdef SMP
396	bl	CNAME(machdep_ap_bootstrap)	/* And away! */
397	nop
398#endif
399
400	/* Should not be reached */
4019:
402	b	9b
403
404cpu_wakeup_handler:
405	GET_TOCBASE(%r2)
406
407	/* Check for false wake up due to badly SRR1 set (eg. by OPAL) */
408	addis	%r3,%r2,TOC_REF(can_wakeup)@ha
409	ld	%r3,TOC_REF(can_wakeup)@l(%r3)
410	ld	%r3,0(%r3)
411	cmpdi	%r3,0
412	beq	cpu_reset_handler
413
414	/* Turn on MMU after return from interrupt */
415	mfsrr1	%r3
416	ori	%r3,%r3,(PSL_IR | PSL_DR)
417	mtsrr1	%r3
418
419	/* Turn on MMU (needed to access PCB) */
420	mfmsr	%r3
421	ori	%r3,%r3,(PSL_IR | PSL_DR)
422	mtmsr	%r3
423	isync
424
425	mfsprg0	%r3
426
427	ld	%r3,PC_CURTHREAD(%r3)	/* Get current thread */
428	ld	%r3,TD_PCB(%r3)		/* Get PCB of current thread */
429	ld	%r12,PCB_CONTEXT(%r3)	/* Load the non-volatile GP regs. */
430	ld	%r13,PCB_CONTEXT+1*8(%r3)
431	ld	%r14,PCB_CONTEXT+2*8(%r3)
432	ld	%r15,PCB_CONTEXT+3*8(%r3)
433	ld	%r16,PCB_CONTEXT+4*8(%r3)
434	ld	%r17,PCB_CONTEXT+5*8(%r3)
435	ld	%r18,PCB_CONTEXT+6*8(%r3)
436	ld	%r19,PCB_CONTEXT+7*8(%r3)
437	ld	%r20,PCB_CONTEXT+8*8(%r3)
438	ld	%r21,PCB_CONTEXT+9*8(%r3)
439	ld	%r22,PCB_CONTEXT+10*8(%r3)
440	ld	%r23,PCB_CONTEXT+11*8(%r3)
441	ld	%r24,PCB_CONTEXT+12*8(%r3)
442	ld	%r25,PCB_CONTEXT+13*8(%r3)
443	ld	%r26,PCB_CONTEXT+14*8(%r3)
444	ld	%r27,PCB_CONTEXT+15*8(%r3)
445	ld	%r28,PCB_CONTEXT+16*8(%r3)
446	ld	%r29,PCB_CONTEXT+17*8(%r3)
447	ld	%r30,PCB_CONTEXT+18*8(%r3)
448	ld	%r31,PCB_CONTEXT+19*8(%r3)
449	ld	%r5,PCB_CR(%r3)		/* Load the condition register */
450	mtcr	%r5
451	ld	%r5,PCB_LR(%r3)		/* Load the link register */
452	mtsrr0	%r5
453	ld	%r1,PCB_SP(%r3)		/* Load the stack pointer */
454	ld	%r2,PCB_TOC(%r3)	/* Load the TOC pointer */
455
456	rfid
457
458/*
459 * This code gets copied to all the trap vectors
460 * (except ISI/DSI, ALI, and the interrupts). Has to fit in 8 instructions!
461 */
462
463	.globl	CNAME(trapcode),CNAME(trapcodeend)
464	.p2align 3
465CNAME(trapcode):
466	mtsprg1	%r1			/* save SP */
467	mflr	%r1			/* Save the old LR in r1 */
468	mtsprg2 %r1			/* And then in SPRG2 */
469	ld	%r1,TRAP_ENTRY(0)
470	mtlr	%r1
471	li	%r1, 0xe0		/* How to get the vector from LR */
472	blrl				/* Branch to generictrap */
473CNAME(trapcodeend):
474
475/* Same thing for traps setting HSRR0/HSRR1 */
476	.globl	CNAME(hypertrapcode),CNAME(hypertrapcodeend)
477	.p2align 3
478CNAME(hypertrapcode):
479	mtsprg1	%r1			/* save SP */
480	mflr	%r1			/* Save the old LR in r1 */
481	mtsprg2 %r1			/* And then in SPRG2 */
482	ld	%r1,TRAP_GENTRAP(0)
483	addi	%r1,%r1,(generichypertrap-generictrap)
484	mtlr	%r1
485	li	%r1, 0xe0		/* How to get the vector from LR */
486	blrl				/* Branch to generichypertrap */
487CNAME(hypertrapcodeend):
488
489/*
490 * For SLB misses: do special things for the kernel
491 *
492 * Note: SPRG1 is always safe to overwrite any time the MMU was on, which is
493 * the only time this can be called.
494 */
495	.globl	CNAME(slbtrap),CNAME(slbtrapend)
496	.p2align 3
497CNAME(slbtrap):
498	/* 0x00 */
499	mtsprg1	%r1			/* save SP */
500	GET_CPUINFO(%r1)
501	std	%r2,(PC_SLBSAVE+16)(%r1)	/* save r2 */
502	mfcr	%r2
503	/* 0x10 */
504	std	%r2,(PC_SLBSAVE+104)(%r1)	/* save CR */
505	mfsrr1	%r2			/* test kernel mode */
506	mtcr	%r2
507	bf	17,2f			/* branch if PSL_PR is false */
508	/* 0x20 */
509	/* User mode */
510	ld	%r2,(PC_SLBSAVE+104)(%r1)
511	mtcr	%r2				/* restore CR */
512	ld	%r2,(PC_SLBSAVE+16)(%r1) 	/* restore r2 */
513	mflr	%r1
514	/* 0x30 */
515	mtsprg2 %r1				/* save LR in SPRG2 */
516	ld	%r1,TRAP_ENTRY(0)		/* real-mode &generictrap */
517	mtlr	%r1
518	li	%r1, 0x80		/* How to get the vector from LR */
519	/* 0x40 */
520	blrl				/* Branch to generictrap */
5212:	mflr	%r2			/* Save the old LR in r2 */
522	/* Kernel mode */
523	ld	%r1,TRAP_GENTRAP(0)		/* Real-mode &generictrap */
524	addi    %r1,%r1,(kern_slbtrap-generictrap)
525	/* 0x50 */
526	mtlr	%r1
527	GET_CPUINFO(%r1)
528	blrl					/* Branch to kern_slbtrap */
529/* must fit in 128 bytes! */
530CNAME(slbtrapend):
531
532/*
533 * On entry:
534 * SPRG1: SP
535 * r1: pcpu
536 * r2: LR
537 * LR: branch address in trap region
538 */
539kern_slbtrap:
540	std	%r2,(PC_SLBSAVE+136)(%r1) /* old LR */
541	std	%r3,(PC_SLBSAVE+24)(%r1) /* save R3 */
542
543	/* Check if this needs to be handled as a regular trap (userseg miss) */
544	mflr	%r2
545	andi.	%r2,%r2,0xff80
546	cmpwi	%r2,EXC_DSE
547	bne	1f
548	mfdar	%r2
549	b	2f
5501:	mfsrr0	%r2
5512:	/* r2 now contains the fault address */
552	lis	%r3,SEGMENT_MASK@highesta
553	ori	%r3,%r3,SEGMENT_MASK@highera
554	sldi	%r3,%r3,32
555	oris	%r3,%r3,SEGMENT_MASK@ha
556	ori	%r3,%r3,SEGMENT_MASK@l
557	and	%r2,%r2,%r3	/* R2 = segment base address */
558	lis	%r3,USER_ADDR@highesta
559	ori	%r3,%r3,USER_ADDR@highera
560	sldi	%r3,%r3,32
561	oris	%r3,%r3,USER_ADDR@ha
562	ori	%r3,%r3,USER_ADDR@l
563	cmpd	%r2,%r3		/* Compare fault base to USER_ADDR */
564	bne	3f
565
566	/* User seg miss, handle as a regular trap */
567	ld	%r2,(PC_SLBSAVE+104)(%r1) /* Restore CR */
568	mtcr	%r2
569	ld	%r2,(PC_SLBSAVE+16)(%r1) /* Restore R2,R3 */
570	ld	%r3,(PC_SLBSAVE+24)(%r1)
571	ld	%r1,(PC_SLBSAVE+136)(%r1) /* Save the old LR in r1 */
572	mtsprg2 %r1			/* And then in SPRG2 */
573	li	%r1, 0x80		/* How to get the vector from LR */
574	b	generictrap		/* Retain old LR using b */
575
5763:	/* Real kernel SLB miss */
577	std	%r0,(PC_SLBSAVE+0)(%r1)	/* free all volatile regs */
578	mfsprg1	%r2			/* Old R1 */
579	std	%r2,(PC_SLBSAVE+8)(%r1)
580	/* R2,R3 already saved */
581	std	%r4,(PC_SLBSAVE+32)(%r1)
582	std	%r5,(PC_SLBSAVE+40)(%r1)
583	std	%r6,(PC_SLBSAVE+48)(%r1)
584	std	%r7,(PC_SLBSAVE+56)(%r1)
585	std	%r8,(PC_SLBSAVE+64)(%r1)
586	std	%r9,(PC_SLBSAVE+72)(%r1)
587	std	%r10,(PC_SLBSAVE+80)(%r1)
588	std	%r11,(PC_SLBSAVE+88)(%r1)
589	std	%r12,(PC_SLBSAVE+96)(%r1)
590	/* CR already saved */
591	mfxer	%r2			/* save XER */
592	std	%r2,(PC_SLBSAVE+112)(%r1)
593	mflr	%r2			/* save LR (SP already saved) */
594	std	%r2,(PC_SLBSAVE+120)(%r1)
595	mfctr	%r2			/* save CTR */
596	std	%r2,(PC_SLBSAVE+128)(%r1)
597
598	/* Call handler */
599	addi	%r1,%r1,PC_SLBSTACK-48+1024
600	li	%r2,~15
601	and	%r1,%r1,%r2
602	GET_TOCBASE(%r2)
603	mflr	%r3
604	andi.	%r3,%r3,0xff80
605	mfdar	%r4
606	mfsrr0	%r5
607	bl	handle_kernel_slb_spill
608	nop
609
610	/* Save r28-31, restore r4-r12 */
611	GET_CPUINFO(%r1)
612	ld	%r4,(PC_SLBSAVE+32)(%r1)
613	ld	%r5,(PC_SLBSAVE+40)(%r1)
614	ld	%r6,(PC_SLBSAVE+48)(%r1)
615	ld	%r7,(PC_SLBSAVE+56)(%r1)
616	ld	%r8,(PC_SLBSAVE+64)(%r1)
617	ld	%r9,(PC_SLBSAVE+72)(%r1)
618	ld	%r10,(PC_SLBSAVE+80)(%r1)
619	ld	%r11,(PC_SLBSAVE+88)(%r1)
620	ld	%r12,(PC_SLBSAVE+96)(%r1)
621	std	%r28,(PC_SLBSAVE+64)(%r1)
622	std	%r29,(PC_SLBSAVE+72)(%r1)
623	std	%r30,(PC_SLBSAVE+80)(%r1)
624	std	%r31,(PC_SLBSAVE+88)(%r1)
625
626	/* Restore kernel mapping */
627	bl	restore_kernsrs
628
629	/* Restore remaining registers */
630	ld	%r28,(PC_SLBSAVE+64)(%r1)
631	ld	%r29,(PC_SLBSAVE+72)(%r1)
632	ld	%r30,(PC_SLBSAVE+80)(%r1)
633	ld	%r31,(PC_SLBSAVE+88)(%r1)
634
635	ld	%r2,(PC_SLBSAVE+104)(%r1)
636	mtcr	%r2
637	ld	%r2,(PC_SLBSAVE+112)(%r1)
638	mtxer	%r2
639	ld	%r2,(PC_SLBSAVE+120)(%r1)
640	mtlr	%r2
641	ld	%r2,(PC_SLBSAVE+128)(%r1)
642	mtctr	%r2
643	ld	%r2,(PC_SLBSAVE+136)(%r1)
644	mtlr	%r2
645
646	/* Restore r0-r3 */
647	ld	%r0,(PC_SLBSAVE+0)(%r1)
648	ld	%r2,(PC_SLBSAVE+16)(%r1)
649	ld	%r3,(PC_SLBSAVE+24)(%r1)
650	mfsprg1	%r1
651
652	/* Back to whatever we were doing */
653	rfid
654
655/*
656 * For ALI: has to save DSISR and DAR
657 */
658	.globl	CNAME(alitrap),CNAME(aliend)
659CNAME(alitrap):
660	mtsprg1	%r1			/* save SP */
661	GET_CPUINFO(%r1)
662	std	%r27,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)	/* free r27-r31 */
663	std	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
664	std	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
665	std	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
666	std	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
667	mfdar	%r30
668	mfdsisr	%r31
669	std	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
670	std	%r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
671	mfsprg1	%r1			/* restore SP, in case of branch */
672	mflr	%r28			/* save LR */
673	mfcr	%r29			/* save CR */
674
675	ld	%r31,TRAP_GENTRAP(0)
676	addi	%r31,%r31,(s_trap - generictrap)
677	mtlr	%r31
678
679	/* Put our exception vector in SPRG3 */
680	li	%r31, EXC_ALI
681	mtsprg3	%r31
682
683	/* Test whether we already had PR set */
684	mfsrr1	%r31
685	mtcr	%r31
686	blrl				/* Branch to s_trap */
687CNAME(aliend):
688
689/*
690 * Similar to the above for DSI
691 * Has to handle standard pagetable spills
692 */
693	.globl	CNAME(dsitrap),CNAME(dsiend)
694	.p2align 3
695CNAME(dsitrap):
696	mtsprg1	%r1			/* save SP */
697	GET_CPUINFO(%r1)
698	std	%r27,(PC_DISISAVE+CPUSAVE_R27)(%r1)	/* free r27-r31 */
699	std	%r28,(PC_DISISAVE+CPUSAVE_R28)(%r1)
700	std	%r29,(PC_DISISAVE+CPUSAVE_R29)(%r1)
701	std	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
702	std	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
703	mfcr	%r29			/* save CR */
704	mfxer	%r30			/* save XER */
705	mtsprg2	%r30			/* in SPRG2 */
706	mfsrr1	%r31			/* test kernel mode */
707	mtcr	%r31
708	mflr	%r28			/* save LR (SP already saved) */
709	ld	%r1,TRAP_GENTRAP(0)
710	addi	%r1,%r1,(disitrap-generictrap)
711	mtlr	%r1
712	blrl				/* Branch to disitrap */
713CNAME(dsiend):
714
715/*
716 * Preamble code for DSI/ISI traps
717 */
718disitrap:
719	/* Write the trap vector to SPRG3 by computing LR & 0xff00 */
720	mflr	%r1
721	andi.	%r1,%r1,0xff00
722	mtsprg3	%r1
723
724	GET_CPUINFO(%r1)
725	ld	%r31,(PC_DISISAVE+CPUSAVE_R27)(%r1)
726	std	%r31,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)
727	ld	%r30,(PC_DISISAVE+CPUSAVE_R28)(%r1)
728	std	%r30,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
729	ld	%r31,(PC_DISISAVE+CPUSAVE_R29)(%r1)
730	std	%r31,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
731	ld	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
732	std	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
733	ld	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
734	std	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
735	mfdar	%r30
736	mfdsisr	%r31
737	std	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
738	std	%r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
739
740#ifdef KDB
741	/* Try to detect a kernel stack overflow */
742	mfsrr1	%r31
743	mtcr	%r31
744	bt	17,realtrap		/* branch is user mode */
745	mfsprg1	%r31			/* get old SP */
746	clrrdi	%r31,%r31,12		/* Round SP down to nearest page */
747	sub.	%r30,%r31,%r30		/* SP - DAR */
748	bge	1f
749	neg	%r30,%r30		/* modulo value */
7501:	cmpldi	%cr0,%r30,4096		/* is DAR within a page of SP? */
751	bge	%cr0,realtrap		/* no, too far away. */
752
753	/* Now convert this DSI into a DDB trap.  */
754	GET_CPUINFO(%r1)
755	ld	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1) /* get DAR */
756	std	%r30,(PC_DBSAVE  +CPUSAVE_AIM_DAR)(%r1) /* save DAR */
757	ld	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1) /* get DSISR */
758	std	%r30,(PC_DBSAVE  +CPUSAVE_AIM_DSISR)(%r1) /* save DSISR */
759	ld	%r31,(PC_DISISAVE+CPUSAVE_R27)(%r1) /* get  r27 */
760	std	%r31,(PC_DBSAVE  +CPUSAVE_R27)(%r1) /* save r27 */
761	ld	%r30,(PC_DISISAVE+CPUSAVE_R28)(%r1) /* get  r28 */
762	std	%r30,(PC_DBSAVE  +CPUSAVE_R28)(%r1) /* save r28 */
763	ld	%r31,(PC_DISISAVE+CPUSAVE_R29)(%r1) /* get  r29 */
764	std	%r31,(PC_DBSAVE  +CPUSAVE_R29)(%r1) /* save r29 */
765	ld	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1) /* get  r30 */
766	std	%r30,(PC_DBSAVE  +CPUSAVE_R30)(%r1) /* save r30 */
767	ld	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1) /* get  r31 */
768	std	%r31,(PC_DBSAVE  +CPUSAVE_R31)(%r1) /* save r31 */
769	b	dbtrap
770#endif
771
772	/* XXX need stack probe here */
773realtrap:
774/* Test whether we already had PR set */
775	mfsrr1	%r1
776	mtcr	%r1
777	mfsprg1	%r1			/* restore SP (might have been
778					   overwritten) */
779	bf	17,k_trap		/* branch if PSL_PR is false */
780	GET_CPUINFO(%r1)
781	mr	%r27,%r28		/* Save LR, r29 */
782	mtsprg2	%r29
783	bl	restore_kernsrs		/* enable kernel mapping */
784	mfsprg2	%r29
785	mr	%r28,%r27
786	ld	%r1,PC_CURPCB(%r1)
787	b	s_trap
788
789/*
790 * generictrap does some standard setup for trap handling to minimize
791 * the code that need be installed in the actual vectors. It expects
792 * the following conditions.
793 *
794 * R1 - Trap vector = LR & (0xff00 | R1)
795 * SPRG1 - Original R1 contents
796 * SPRG2 - Original LR
797 */
798
799generichypertrap:
800	mtsprg3 %r1
801	mfspr	%r1, SPR_HSRR0
802	mtsrr0	%r1
803	mfspr	%r1, SPR_HSRR1
804	mtsrr1	%r1
805	mfsprg3	%r1
806	.globl	CNAME(generictrap)
807generictrap:
808	/* Save R1 for computing the exception vector */
809	mtsprg3 %r1
810
811	/* Save interesting registers */
812	GET_CPUINFO(%r1)
813	std	%r27,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)	/* free r27-r31 */
814	std	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
815	std	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
816	std	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
817	std	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
818	mfdar	%r30
819	std	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
820	mfdsisr	%r30
821	std	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
822	mfsprg1	%r1			/* restore SP, in case of branch */
823	mfsprg2	%r28			/* save LR */
824	mfcr	%r29			/* save CR */
825
826	/* Compute the exception vector from the link register */
827	mfsprg3 %r31
828	ori	%r31,%r31,0xff00
829	mflr	%r30
830	addi	%r30,%r30,-4 /* The branch instruction, not the next */
831	and	%r30,%r30,%r31
832	mtsprg3	%r30
833
834	/* Test whether we already had PR set */
835	mfsrr1	%r31
836	mtcr	%r31
837
838s_trap:
839	bf	17,k_trap		/* branch if PSL_PR is false */
840	GET_CPUINFO(%r1)
841u_trap:
842	mr	%r27,%r28		/* Save LR, r29 */
843	mtsprg2	%r29
844	bl	restore_kernsrs		/* enable kernel mapping */
845	mfsprg2	%r29
846	mr	%r28,%r27
847	ld	%r1,PC_CURPCB(%r1)
848
849/*
850 * Now the common trap catching code.
851 */
852k_trap:
853	FRAME_SETUP(PC_TEMPSAVE)
854/* Call C interrupt dispatcher: */
855trapagain:
856	GET_TOCBASE(%r2)
857	addi	%r3,%r1,48
858	bl	CNAME(powerpc_interrupt)
859	nop
860
861	.globl	CNAME(trapexit)	/* backtrace code sentinel */
862CNAME(trapexit):
863/* Disable interrupts: */
864	mfmsr	%r3
865	andi.	%r3,%r3,~PSL_EE@l
866	mtmsr	%r3
867	isync
868/* Test AST pending: */
869	ld	%r5,FRAME_SRR1+48(%r1)
870	mtcr	%r5
871	bf	17,1f			/* branch if PSL_PR is false */
872
873	GET_CPUINFO(%r3)		/* get per-CPU pointer */
874	lwz	%r4,TD_AST(%r13)	/* get thread ast value */
875	cmpwi	%r4,0
876	beq	1f
877	mfmsr	%r3			/* re-enable interrupts */
878	ori	%r3,%r3,PSL_EE@l
879	mtmsr	%r3
880	isync
881	GET_TOCBASE(%r2)
882	addi	%r3,%r1,48
883	bl	CNAME(ast)
884	nop
885	.globl	CNAME(asttrapexit)	/* backtrace code sentinel #2 */
886CNAME(asttrapexit):
887	b	trapexit		/* test ast ret value ? */
8881:
889	FRAME_LEAVE(PC_TEMPSAVE)
890	rfid
891
892#if defined(KDB)
893/*
894 * Deliberate entry to dbtrap
895 */
896ASENTRY_NOPROF(breakpoint)
897	mtsprg1	%r1
898	mfmsr	%r3
899	mtsrr1	%r3
900	andi.	%r3,%r3,~(PSL_EE|PSL_ME)@l
901	mtmsr	%r3			/* disable interrupts */
902	isync
903	GET_CPUINFO(%r3)
904	std	%r27,(PC_DBSAVE+CPUSAVE_R27)(%r3)
905	std	%r28,(PC_DBSAVE+CPUSAVE_R28)(%r3)
906	std	%r29,(PC_DBSAVE+CPUSAVE_R29)(%r3)
907	std	%r30,(PC_DBSAVE+CPUSAVE_R30)(%r3)
908	std	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r3)
909	mflr	%r28
910	li	%r29,EXC_BPT
911	mtlr	%r29
912	mfcr	%r29
913	mtsrr0	%r28
914
915/*
916 * Now the kdb trap catching code.
917 */
918dbtrap:
919	/* Write the trap vector to SPRG3 by computing LR & 0xff00 */
920	mflr	%r1
921	andi.	%r1,%r1,0xff00
922	mtsprg3	%r1
923
924	GET_TOCBASE(%r1)			/* get new SP */
925	addis	%r1,%r1,TOC_REF(trapstk)@ha
926	ld	%r1,TOC_REF(trapstk)@l(%r1)
927	addi	%r1,%r1,(TRAPSTKSZ-48)
928
929	FRAME_SETUP(PC_DBSAVE)
930/* Call C trap code: */
931	GET_TOCBASE(%r2)
932	addi	%r3,%r1,48
933	bl	CNAME(db_trap_glue)
934	nop
935	or.	%r3,%r3,%r3
936	bne	dbleave
937/* This wasn't for KDB, so switch to real trap: */
938	ld	%r3,FRAME_EXC+48(%r1)	/* save exception */
939	GET_CPUINFO(%r4)
940	std	%r3,(PC_DBSAVE+CPUSAVE_R31)(%r4)
941	FRAME_LEAVE(PC_DBSAVE)
942	mtsprg1	%r1			/* prepare for entrance to realtrap */
943	GET_CPUINFO(%r1)
944	std	%r27,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)
945	std	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
946	std	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
947	std	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
948	std	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
949	mflr	%r28
950	mfcr	%r29
951	ld	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r1)
952	mtsprg3	%r31			/* SPRG3 was clobbered by FRAME_LEAVE */
953	mfsprg1	%r1
954	b	realtrap
955dbleave:
956	FRAME_LEAVE(PC_DBSAVE)
957	rfid
958ASEND(breakpoint)
959
960/*
961 * In case of KDB we want a separate trap catcher for it
962 */
963	.globl	CNAME(dblow),CNAME(dbend)
964	.p2align 3
965CNAME(dblow):
966	mtsprg1	%r1			/* save SP */
967	mtsprg2	%r29			/* save r29 */
968	mfcr	%r29			/* save CR in r29 */
969	mfsrr1	%r1
970	mtcr	%r1
971	bf	17,1f			/* branch if privileged */
972
973	/* Unprivileged case */
974	mtcr	%r29			/* put the condition register back */
975        mfsprg2	%r29			/* ... and r29 */
976        mflr	%r1			/* save LR */
977	mtsprg2 %r1			/* And then in SPRG2 */
978
979	ld	%r1, TRAP_ENTRY(0)	/* Get branch address */
980	mtlr	%r1
981	li	%r1, 0	 		/* How to get the vector from LR */
982	blrl				/* Branch to generictrap */
983	/* No fallthrough */
9841:
985	GET_CPUINFO(%r1)
986	std	%r27,(PC_DBSAVE+CPUSAVE_R27)(%r1)	/* free r27 */
987	std	%r28,(PC_DBSAVE+CPUSAVE_R28)(%r1)	/* free r28 */
988        mfsprg2	%r28				/* r29 holds cr...  */
989        std	%r28,(PC_DBSAVE+CPUSAVE_R29)(%r1)	/* free r29 */
990        std	%r30,(PC_DBSAVE+CPUSAVE_R30)(%r1)	/* free r30 */
991        std	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r1)	/* free r31 */
992        mflr	%r28					/* save LR */
993	ld	%r1,TRAP_GENTRAP(0)
994	addi	%r1,%r1,(dbtrap-generictrap)
995	mtlr	%r1
996	blrl				/* Branch to dbtrap */
997CNAME(dbend):
998#endif /* KDB */
999