xref: /freebsd/sys/powerpc/aim/trap_subr32.S (revision 52baf267be42c3e14a9d843c24c953efae7195bd)
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#define RESTORE_SRS(pmap,sr)	mtsr    0,sr; \
46	lwz	sr,1*4(pmap);	mtsr	1,sr; \
47	lwz	sr,2*4(pmap);	mtsr	2,sr; \
48	lwz	sr,3*4(pmap);	mtsr	3,sr; \
49	lwz	sr,4*4(pmap);	mtsr	4,sr; \
50	lwz	sr,5*4(pmap);	mtsr	5,sr; \
51	lwz	sr,6*4(pmap);	mtsr	6,sr; \
52	lwz	sr,7*4(pmap);	mtsr	7,sr; \
53	lwz	sr,8*4(pmap);	mtsr	8,sr; \
54	lwz	sr,9*4(pmap);	mtsr	9,sr; \
55	lwz	sr,10*4(pmap);	mtsr	10,sr; \
56	lwz	sr,11*4(pmap);	mtsr	11,sr; \
57	/* Skip segment 12 (USER_SR), which is restored differently */ \
58	lwz	sr,13*4(pmap);	mtsr	13,sr; \
59	lwz	sr,14*4(pmap);	mtsr	14,sr; \
60	lwz	sr,15*4(pmap);	mtsr	15,sr; isync;
61
62/*
63 * User SRs are loaded through a pointer to the current pmap.
64 */
65#define RESTORE_USER_SRS(pmap,sr) \
66	GET_CPUINFO(pmap); \
67	lwz	pmap,PC_CURPMAP(pmap); \
68	lwzu	sr,PM_SR(pmap); \
69	RESTORE_SRS(pmap,sr) \
70	/* Restore SR 12 */ \
71	lwz	sr,12*4(pmap);	mtsr	12,sr
72
73/*
74 * Kernel SRs are loaded directly from kernel_pmap_
75 */
76#define RESTORE_KERN_SRS(pmap,sr) \
77	lis	pmap,CNAME(kernel_pmap_store)@ha; \
78	lwzu	sr,CNAME(kernel_pmap_store)+PM_SR@l(pmap); \
79	RESTORE_SRS(pmap,sr)
80
81/*
82 * FRAME_SETUP assumes:
83 *	SPRG1		SP (1)
84 * 	SPRG3		trap type
85 *	savearea	r28-r31,DAR,DSISR   (DAR & DSISR only for DSI traps)
86 *	r28		LR
87 *	r29		CR
88 *	r30		scratch
89 *	r31		scratch
90 *	r1		kernel stack
91 *	SRR0/1		as at start of trap
92 */
93#define	FRAME_SETUP(savearea)						\
94/* Have to enable translation to allow access of kernel stack: */	\
95	GET_CPUINFO(%r31);						\
96	mfsrr0	%r30;							\
97	stw	%r30,(savearea+CPUSAVE_SRR0)(%r31);	/* save SRR0 */	\
98	mfsrr1	%r30;							\
99	stw	%r30,(savearea+CPUSAVE_SRR1)(%r31);	/* save SRR1 */	\
100	mfmsr	%r30;							\
101	ori	%r30,%r30,(PSL_DR|PSL_IR|PSL_RI)@l; /* relocation on */	\
102	mtmsr	%r30;			/* stack can now be accessed */	\
103	isync;								\
104	mfsprg1	%r31;			/* get saved SP */		\
105	stwu	%r31,-FRAMELEN(%r1);	/* save it in the callframe */	\
106	stw	%r0, FRAME_0+8(%r1);	/* save r0 in the trapframe */	\
107	stw	%r31,FRAME_1+8(%r1);	/* save SP   "      "       */	\
108	stw	%r2, FRAME_2+8(%r1);	/* save r2   "      "       */	\
109	stw	%r28,FRAME_LR+8(%r1);	/* save LR   "      "       */	\
110	stw	%r29,FRAME_CR+8(%r1);	/* save CR   "      "       */	\
111	GET_CPUINFO(%r2);						\
112	lwz	%r28,(savearea+CPUSAVE_R28)(%r2); /* get saved r28 */	\
113	lwz	%r29,(savearea+CPUSAVE_R29)(%r2); /* get saved r29 */	\
114	lwz	%r30,(savearea+CPUSAVE_R30)(%r2); /* get saved r30 */	\
115	lwz	%r31,(savearea+CPUSAVE_R31)(%r2); /* get saved r31 */	\
116	stw	%r3,  FRAME_3+8(%r1);	/* save r3-r31 */		\
117	stw	%r4,  FRAME_4+8(%r1);					\
118	stw	%r5,  FRAME_5+8(%r1);					\
119	stw	%r6,  FRAME_6+8(%r1);					\
120	stw	%r7,  FRAME_7+8(%r1);					\
121	stw	%r8,  FRAME_8+8(%r1);					\
122	stw	%r9,  FRAME_9+8(%r1);					\
123	stw	%r10, FRAME_10+8(%r1);					\
124	stw	%r11, FRAME_11+8(%r1);					\
125	stw	%r12, FRAME_12+8(%r1);					\
126	stw	%r13, FRAME_13+8(%r1);					\
127	stw	%r14, FRAME_14+8(%r1);					\
128	stw	%r15, FRAME_15+8(%r1);					\
129	stw	%r16, FRAME_16+8(%r1);					\
130	stw	%r17, FRAME_17+8(%r1);					\
131	stw	%r18, FRAME_18+8(%r1);					\
132	stw	%r19, FRAME_19+8(%r1);					\
133	stw	%r20, FRAME_20+8(%r1);					\
134	stw	%r21, FRAME_21+8(%r1);					\
135	stw	%r22, FRAME_22+8(%r1);					\
136	stw	%r23, FRAME_23+8(%r1);					\
137	stw	%r24, FRAME_24+8(%r1);					\
138	stw	%r25, FRAME_25+8(%r1);					\
139	stw	%r26, FRAME_26+8(%r1);					\
140	stw	%r27, FRAME_27+8(%r1);					\
141	stw	%r28, FRAME_28+8(%r1);					\
142	stw	%r29, FRAME_29+8(%r1);					\
143	stw	%r30, FRAME_30+8(%r1);					\
144	stw	%r31, FRAME_31+8(%r1);					\
145	lwz	%r28,(savearea+CPUSAVE_AIM_DAR)(%r2);  /* saved DAR */	\
146	lwz	%r29,(savearea+CPUSAVE_AIM_DSISR)(%r2);/* saved DSISR */\
147	lwz	%r30,(savearea+CPUSAVE_SRR0)(%r2); /* saved SRR0 */	\
148	lwz	%r31,(savearea+CPUSAVE_SRR1)(%r2); /* saved SRR1 */	\
149	mfxer	%r3;							\
150	mfctr	%r4;							\
151	mfsprg3	%r5;							\
152	stw	%r3, FRAME_XER+8(1);	/* save xer/ctr/exc */		\
153	stw	%r4, FRAME_CTR+8(1);					\
154	stw	%r5, FRAME_EXC+8(1);					\
155	stw	%r28,FRAME_AIM_DAR+8(1);				\
156	stw	%r29,FRAME_AIM_DSISR+8(1); /* save dsisr/srr0/srr1 */	\
157	stw	%r30,FRAME_SRR0+8(1);					\
158	stw	%r31,FRAME_SRR1+8(1);					\
159	lwz	%r2,PC_CURTHREAD(%r2)	/* set curthread pointer */
160
161#define	FRAME_LEAVE(savearea)						\
162/* Disable exceptions: */						\
163	mfmsr	%r2;							\
164	andi.	%r2,%r2,~PSL_EE@l;					\
165	mtmsr	%r2;							\
166	isync;								\
167/* Now restore regs: */							\
168	lwz	%r2,FRAME_SRR0+8(%r1);					\
169	lwz	%r3,FRAME_SRR1+8(%r1);					\
170	lwz	%r4,FRAME_CTR+8(%r1);					\
171	lwz	%r5,FRAME_XER+8(%r1);					\
172	lwz	%r6,FRAME_LR+8(%r1);					\
173	GET_CPUINFO(%r7);						\
174	stw	%r2,(savearea+CPUSAVE_SRR0)(%r7); /* save SRR0 */	\
175	stw	%r3,(savearea+CPUSAVE_SRR1)(%r7); /* save SRR1 */	\
176	lwz	%r7,FRAME_CR+8(%r1);					\
177	mtctr	%r4;							\
178	mtxer	%r5;							\
179	mtlr	%r6;							\
180	mtsprg1	%r7;			/* save cr */			\
181	lwz	%r31,FRAME_31+8(%r1);   /* restore r0-31 */		\
182	lwz	%r30,FRAME_30+8(%r1);					\
183	lwz	%r29,FRAME_29+8(%r1);					\
184	lwz	%r28,FRAME_28+8(%r1);					\
185	lwz	%r27,FRAME_27+8(%r1);					\
186	lwz	%r26,FRAME_26+8(%r1);					\
187	lwz	%r25,FRAME_25+8(%r1);					\
188	lwz	%r24,FRAME_24+8(%r1);					\
189	lwz	%r23,FRAME_23+8(%r1);					\
190	lwz	%r22,FRAME_22+8(%r1);					\
191	lwz	%r21,FRAME_21+8(%r1);					\
192	lwz	%r20,FRAME_20+8(%r1);					\
193	lwz	%r19,FRAME_19+8(%r1);					\
194	lwz	%r18,FRAME_18+8(%r1);					\
195	lwz	%r17,FRAME_17+8(%r1);					\
196	lwz	%r16,FRAME_16+8(%r1);					\
197	lwz	%r15,FRAME_15+8(%r1);					\
198	lwz	%r14,FRAME_14+8(%r1);					\
199	lwz	%r13,FRAME_13+8(%r1);					\
200	lwz	%r12,FRAME_12+8(%r1);					\
201	lwz	%r11,FRAME_11+8(%r1);					\
202	lwz	%r10,FRAME_10+8(%r1);					\
203	lwz	%r9, FRAME_9+8(%r1);					\
204	lwz	%r8, FRAME_8+8(%r1);					\
205	lwz	%r7, FRAME_7+8(%r1);					\
206	lwz	%r6, FRAME_6+8(%r1);					\
207	lwz	%r5, FRAME_5+8(%r1);					\
208	lwz	%r4, FRAME_4+8(%r1);					\
209	lwz	%r3, FRAME_3+8(%r1);					\
210	lwz	%r2, FRAME_2+8(%r1);					\
211	lwz	%r0, FRAME_0+8(%r1);					\
212	lwz	%r1, FRAME_1+8(%r1);					\
213/* Can't touch %r1 from here on */					\
214	mtsprg2	%r2;			/* save r2 & r3 */		\
215	mtsprg3	%r3;							\
216/* Disable translation, machine check and recoverability: */		\
217	mfmsr	%r2;							\
218	andi.	%r2,%r2,~(PSL_DR|PSL_IR|PSL_ME|PSL_RI)@l;	\
219	mtmsr	%r2;							\
220	isync;								\
221/* Decide whether we return to user mode: */				\
222	GET_CPUINFO(%r2);						\
223	lwz	%r3,(savearea+CPUSAVE_SRR1)(%r2);			\
224	mtcr	%r3;							\
225	bf	17,1f;			/* branch if PSL_PR is false */	\
226/* Restore user SRs */							\
227	RESTORE_USER_SRS(%r2,%r3);					\
2281:	mfsprg1	%r2;			/* restore cr */		\
229	mtcr	%r2;							\
230	GET_CPUINFO(%r2);						\
231	lwz	%r3,(savearea+CPUSAVE_SRR0)(%r2); /* restore srr0 */	\
232	mtsrr0	%r3;							\
233	lwz	%r3,(savearea+CPUSAVE_SRR1)(%r2); /* restore srr1 */	\
234									\
235	/* Make sure HV bit of MSR propagated to SRR1 */		\
236	mfmsr	%r2;							\
237	or	%r3,%r2,%r3;						\
238									\
239	mtsrr1	%r3;							\
240	mfsprg2	%r2;			/* restore r2 & r3 */		\
241	mfsprg3	%r3
242
243/*
244 * The next two routines are 64-bit glue code. The first is used to test if
245 * we are on a 64-bit system. By copying it to the illegal instruction
246 * handler, we can test for 64-bit mode by trying to execute a 64-bit
247 * instruction and seeing what happens. The second gets copied in front
248 * of all the other handlers to restore 32-bit bridge mode when traps
249 * are taken.
250 */
251
252/* 64-bit test code. Sets SPRG2 to 0 if an illegal instruction is executed */
253
254	.globl	CNAME(testppc64),CNAME(testppc64size)
255CNAME(testppc64):
256	mtsprg1 %r31
257	mfsrr0  %r31
258	addi	%r31, %r31, 4
259	mtsrr0  %r31
260
261	li	%r31, 0
262	mtsprg2 %r31
263	mfsprg1 %r31
264
265	rfi
266CNAME(testppc64size) = .-CNAME(testppc64)
267
268
269/* 64-bit bridge mode restore snippet. Gets copied in front of everything else
270 * on 64-bit systems. */
271
272	.globl	CNAME(restorebridge),CNAME(restorebridgesize)
273CNAME(restorebridge):
274	mtsprg1	%r31
275	mfmsr	%r31
276	clrldi	%r31,%r31,1
277	mtmsrd	%r31
278	mfsprg1	%r31
279	isync
280CNAME(restorebridgesize) = .-CNAME(restorebridge)
281
282#ifdef SMP
283/*
284 * Processor reset exception handler. These are typically
285 * the first instructions the processor executes after a
286 * software reset. We do this in two bits so that we are
287 * not still hanging around in the trap handling region
288 * once the MMU is turned on.
289 */
290	.globl	CNAME(rstcode), CNAME(rstsize)
291CNAME(rstcode):
292	ba	cpu_reset
293CNAME(rstsize) = . - CNAME(rstcode)
294
295cpu_reset:
296	bl	1f
297
298	.space	124
299
3001:
301	mflr	%r1
302	addi	%r1,%r1,(124-16)@l
303
304	lis	%r3,1@l
305	bla	CNAME(cpudep_ap_early_bootstrap)
306	lis	%r3,1@l
307	bla	CNAME(pmap_cpu_bootstrap)
308	bla	CNAME(cpudep_ap_bootstrap)
309	mr	%r1,%r3
310	bla	CNAME(machdep_ap_bootstrap)
311
312	/* Should not be reached */
3139:
314	b	9b
315#endif
316
317/*
318 * This code gets copied to all the trap vectors
319 * (except ISI/DSI, ALI, and the interrupts)
320 */
321
322	.globl	CNAME(trapcode),CNAME(trapsize)
323CNAME(trapcode):
324	mtsprg1	%r1			/* save SP */
325	mflr	%r1			/* Save the old LR in r1 */
326	mtsprg2 %r1			/* And then in SPRG2 */
327	li	%r1, 0x20		/* How to get the vector from LR */
328	bla	generictrap		/* LR & SPRG3 is exception # */
329CNAME(trapsize) = .-CNAME(trapcode)
330
331/*
332 * 64-bit version of trapcode. Identical, except it calls generictrap64.
333 */
334	.globl	CNAME(trapcode64)
335CNAME(trapcode64):
336	mtsprg1	%r1			/* save SP */
337	mflr	%r1			/* Save the old LR in r1 */
338	mtsprg2 %r1			/* And then in SPRG2 */
339	li	%r1, 0x20		/* How to get the vector from LR */
340	bla	generictrap64		/* LR & SPRG3 is exception # */
341
342/*
343 * For ALI: has to save DSISR and DAR
344 */
345	.globl	CNAME(alitrap),CNAME(alisize)
346CNAME(alitrap):
347	mtsprg1	%r1			/* save SP */
348	GET_CPUINFO(%r1)
349	stw	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)	/* free r28-r31 */
350	stw	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
351	stw	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
352	stw	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
353	mfdar	%r30
354	mfdsisr	%r31
355	stw	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
356	stw	%r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
357	mfsprg1	%r1			/* restore SP, in case of branch */
358	mflr	%r28			/* save LR */
359	mfcr	%r29			/* save CR */
360
361	/* Put our exception vector in SPRG3 */
362	li	%r31, EXC_ALI
363	mtsprg3	%r31
364
365	/* Test whether we already had PR set */
366	mfsrr1	%r31
367	mtcr	%r31
368	bla	s_trap
369CNAME(alisize) = .-CNAME(alitrap)
370
371/*
372 * G2 specific: instuction TLB miss.
373 */
374	.globl	CNAME(imisstrap),CNAME(imisssize)
375CNAME(imisstrap):
376	mfspr %r2, SPR_HASH1		/* get first pointer */
377	addi %r1, 0, 8			/* load 8 for counter */
378	mfctr %r0			/* save counter */
379	mfspr %r3, SPR_ICMP		/* get first compare value */
380	addi %r2, %r2, -8		/* pre dec the pointer */
381im0:
382	mtctr %r1			/* load counter */
383im1:
384	lwzu %r1, 8(%r2)		/* get next pte */
385	cmp 0, %r1, %r3			/* see if found pte */
386	bdnzf 2, im1			/* dec count br if cmp ne and if
387					 * count not zero */
388	bne instr_sec_hash		/* if not found set up second hash
389					 * or exit */
390	lwz %r1, +4(%r2)		/* load tlb entry lower-word */
391	andi. %r3, %r1, 8		/* check G bit */
392	bne do_isi_prot			/* if guarded, take an ISI */
393	mtctr %r0			/* restore counter */
394	mfspr %r0, SPR_IMISS		/* get the miss address for the tlbli */
395	mfspr %r3, SPR_SRR1		/* get the saved cr0 bits */
396	mtcrf 0x80, %r3			/* restore CR0 */
397	mtspr SPR_RPA, %r1		/* set the pte */
398	ori %r1, %r1, 0x100		/* set reference bit */
399	srwi %r1, %r1, 8		/* get byte 7 of pte */
400	tlbli %r0 			/* load the itlb */
401	stb %r1, +6(%r2)		/* update page table */
402	rfi				/* return to executing program */
403
404instr_sec_hash:
405	andi. %r1, %r3, 0x0040		/* see if we have done second hash */
406	bne do_isi			/* if so, go to ISI interrupt */
407	mfspr %r2, SPR_HASH2		/* get the second pointer */
408	ori %r3, %r3, 0x0040		/* change the compare value */
409	addi %r1, %r0, 8		/* load 8 for counter */
410	addi %r2, %r2, -8		/* pre dec for update on load */
411	b im0				/* try second hash */
412
413/* Create a faked ISI interrupt as the address was not found */
414do_isi_prot:
415	mfspr %r3, SPR_SRR1		/* get srr1 */
416	andi. %r2, %r3, 0xffff		/* clean upper srr1 */
417	addis %r2, %r2, 0x0800		/* or in srr<4> = 1 to flag prot
418					 * violation */
419	b isi1
420do_isi:
421	mfspr %r3, SPR_SRR1		/* get srr1 */
422	andi. %r2, %r3, 0xffff		/* clean srr1 */
423	addis %r2, %r2, 0x4000		/* or in srr1<1> = 1 to flag pte
424					 * not found */
425isi1:
426	mtctr %r0			/* restore counter */
427	mtspr SPR_SRR1, %r2		/* set srr1 */
428	mfmsr %r0			/* get msr */
429	xoris %r0, %r0, 0x2		/* flip the msr<tgpr> bit */
430	mtcrf 0x80, %r3			/* restore CR0 */
431	mtmsr %r0			/* flip back to the native gprs */
432	ba EXC_ISI			/* go to instr. access interrupt */
433
434CNAME(imisssize) = .-CNAME(imisstrap)
435
436/*
437 * G2 specific: data load TLB miss.
438 */
439	.globl	CNAME(dlmisstrap),CNAME(dlmisssize)
440CNAME(dlmisstrap):
441	mfspr %r2, SPR_HASH1		/* get first pointer */
442	addi %r1, 0, 8			/* load 8 for counter */
443	mfctr %r0			/* save counter */
444	mfspr %r3, SPR_DCMP		/* get first compare value */
445	addi %r2, %r2, -8		/* pre dec the pointer */
446dm0:
447	mtctr %r1			/* load counter */
448dm1:
449	lwzu %r1, 8(%r2)		/* get next pte */
450	cmp 0, 0, %r1, %r3		/* see if found pte */
451	bdnzf 2, dm1			/* dec count br if cmp ne and if
452					 * count not zero */
453	bne data_sec_hash		/* if not found set up second hash
454					 * or exit */
455	lwz %r1, +4(%r2)		/* load tlb entry lower-word */
456	mtctr %r0			/* restore counter */
457	mfspr %r0, SPR_DMISS		/* get the miss address for the tlbld */
458	mfspr %r3, SPR_SRR1		/* get the saved cr0 bits */
459	mtcrf 0x80, %r3			/* restore CR0 */
460	mtspr SPR_RPA, %r1		/* set the pte */
461	ori %r1, %r1, 0x100		/* set reference bit */
462	srwi %r1, %r1, 8		/* get byte 7 of pte */
463	tlbld %r0			/* load the dtlb */
464	stb %r1, +6(%r2)		/* update page table */
465	rfi				/* return to executing program */
466
467data_sec_hash:
468	andi. %r1, %r3, 0x0040		/* see if we have done second hash */
469	bne do_dsi			/* if so, go to DSI interrupt */
470	mfspr %r2, SPR_HASH2		/* get the second pointer */
471	ori %r3, %r3, 0x0040		/* change the compare value */
472	addi %r1, 0, 8			/* load 8 for counter */
473	addi %r2, %r2, -8		/* pre dec for update on load */
474	b dm0				/* try second hash */
475
476CNAME(dlmisssize) = .-CNAME(dlmisstrap)
477
478/*
479 *  G2 specific: data store TLB miss.
480 */
481	.globl	CNAME(dsmisstrap),CNAME(dsmisssize)
482CNAME(dsmisstrap):
483	mfspr %r2, SPR_HASH1		/* get first pointer */
484	addi %r1, 0, 8			/* load 8 for counter */
485	mfctr %r0			/* save counter */
486	mfspr %r3, SPR_DCMP		/* get first compare value */
487	addi %r2, %r2, -8		/* pre dec the pointer */
488ds0:
489	mtctr %r1			/* load counter */
490ds1:
491	lwzu %r1, 8(%r2)		/* get next pte */
492	cmp 0, 0, %r1, %r3		/* see if found pte */
493	bdnzf 2, ds1			/* dec count br if cmp ne and if
494					 * count not zero */
495	bne data_store_sec_hash		/* if not found set up second hash
496					 * or exit */
497	lwz %r1, +4(%r2)		/* load tlb entry lower-word */
498	andi. %r3, %r1, 0x80		/* check the C-bit */
499	beq data_store_chk_prot		/* if (C==0)
500					 *     go check protection modes */
501ds2:
502	mtctr %r0			/* restore counter */
503	mfspr %r0, SPR_DMISS		/* get the miss address for the tlbld */
504	mfspr %r3, SPR_SRR1		/* get the saved cr0 bits */
505	mtcrf 0x80, %r3			/* restore CR0 */
506	mtspr SPR_RPA, %r1		/* set the pte */
507	tlbld %r0			/* load the dtlb */
508	rfi				/* return to executing program */
509
510data_store_sec_hash:
511	andi. %r1, %r3, 0x0040		/* see if we have done second hash */
512	bne do_dsi			/* if so, go to DSI interrupt */
513	mfspr %r2, SPR_HASH2		/* get the second pointer */
514	ori %r3, %r3, 0x0040		/* change the compare value */
515	addi %r1, 0, 8			/* load 8 for counter */
516	addi %r2, %r2, -8		/* pre dec for update on load */
517	b ds0				/* try second hash */
518
519/* Check the protection before setting PTE(c-bit) */
520data_store_chk_prot:
521	rlwinm. %r3,%r1,30,0,1		/* test PP */
522	bge- chk0			/* if (PP == 00 or PP == 01)
523					 *     goto chk0: */
524	andi. %r3, %r1, 1		/* test PP[0] */
525	beq+ chk2			/* return if PP[0] == 0 */
526	b do_dsi_prot			/* else DSIp */
527chk0:
528	mfspr %r3,SPR_SRR1		/* get old msr */
529	andis. %r3,%r3,0x0008		/* test the KEY bit (SRR1-bit 12) */
530	beq chk2			/* if (KEY==0) goto chk2: */
531	b do_dsi_prot			/* else do_dsi_prot */
532chk2:
533	ori %r1, %r1, 0x180		/* set reference and change bit */
534	sth %r1, 6(%r2)			/* update page table */
535	b ds2				/* and back we go */
536
537/* Create a faked DSI interrupt as the address was not found */
538do_dsi:
539	mfspr %r3, SPR_SRR1		/* get srr1 */
540	rlwinm %r1,%r3,9,6,6		/* get srr1<flag> to bit 6 for
541					 * load/store, zero rest */
542	addis %r1, %r1, 0x4000		/* or in dsisr<1> = 1 to flag pte
543					 * not found */
544	b dsi1
545
546do_dsi_prot:
547	mfspr %r3, SPR_SRR1		/* get srr1 */
548	rlwinm %r1,%r3,9,6,6		/* get srr1<flag> to bit 6 for
549					   *load/store, zero rest */
550	addis %r1, %r1, 0x0800		/* or in dsisr<4> = 1 to flag prot
551					 * violation */
552
553dsi1:
554	mtctr %r0			/* restore counter */
555	andi. %r2, %r3, 0xffff		/* clear upper bits of srr1 */
556	mtspr SPR_SRR1, %r2		/* set srr1 */
557	mtspr SPR_DSISR, %r1		/* load the dsisr */
558	mfspr %r1, SPR_DMISS		/* get miss address */
559	rlwinm. %r2,%r2,0,31,31		/* test LE bit */
560	beq dsi2			/* if little endian then: */
561	xor %r1, %r1, 0x07		/* de-mung the data address */
562dsi2:
563	mtspr SPR_DAR, %r1		/* put in dar */
564	mfmsr %r0			/* get msr */
565	xoris %r0, %r0, 0x2		/* flip the msr<tgpr> bit */
566	mtcrf 0x80, %r3			/* restore CR0 */
567	mtmsr %r0			/* flip back to the native gprs */
568	ba EXC_DSI			/* branch to DSI interrupt */
569
570CNAME(dsmisssize) = .-CNAME(dsmisstrap)
571
572/*
573 * Similar to the above for DSI
574 * Has to handle BAT spills
575 * and standard pagetable spills
576 */
577	.globl	CNAME(dsitrap),CNAME(dsisize)
578CNAME(dsitrap):
579	mtsprg1	%r1			/* save SP */
580	GET_CPUINFO(%r1)
581	stw	%r28,(PC_DISISAVE+CPUSAVE_R28)(%r1)	/* free r28-r31 */
582	stw	%r29,(PC_DISISAVE+CPUSAVE_R29)(%r1)
583	stw	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
584	stw	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
585	mfsprg1	%r1			/* restore SP */
586	mfcr	%r29			/* save CR */
587	mfxer	%r30			/* save XER */
588	mtsprg2	%r30			/* in SPRG2 */
589	mfsrr1	%r31			/* test kernel mode */
590	mtcr	%r31
591	bt	17,1f			/* branch if PSL_PR is set */
592	mfdar	%r31			/* get fault address */
593	rlwinm	%r31,%r31,7,25,28	/* get segment * 8 */
594
595	/* get batu */
596	addis	%r31,%r31,CNAME(battable)@ha
597	lwz	%r30,CNAME(battable)@l(31)
598	mtcr	%r30
599	bf	30,1f			/* branch if supervisor valid is
600					   false */
601	/* get batl */
602	lwz	%r31,CNAME(battable)+4@l(31)
603/* We randomly use the highest two bat registers here */
604	mftb	%r28
605	andi.	%r28,%r28,1
606	bne	2f
607	mtdbatu	2,%r30
608	mtdbatl	2,%r31
609	b	3f
6102:
611	mtdbatu	3,%r30
612	mtdbatl	3,%r31
6133:
614	mfsprg2	%r30			/* restore XER */
615	mtxer	%r30
616	mtcr	%r29			/* restore CR */
617	mtsprg1	%r1
618	GET_CPUINFO(%r1)
619	lwz	%r28,(PC_DISISAVE+CPUSAVE_R28)(%r1)	/* restore r28-r31 */
620	lwz	%r29,(PC_DISISAVE+CPUSAVE_R29)(%r1)
621	lwz	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
622	lwz	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
623	mfsprg1	%r1
624	rfi				/* return to trapped code */
6251:
626	mflr	%r28			/* save LR (SP already saved) */
627	bla	disitrap
628CNAME(dsisize) = .-CNAME(dsitrap)
629
630/*
631 * Preamble code for DSI/ISI traps
632 */
633disitrap:
634	/* Write the trap vector to SPRG3 by computing LR & 0xff00 */
635	mflr	%r1
636	andi.	%r1,%r1,0xff00
637	mtsprg3	%r1
638
639	GET_CPUINFO(%r1)
640	lwz	%r30,(PC_DISISAVE+CPUSAVE_R28)(%r1)
641	stw	%r30,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
642	lwz	%r31,(PC_DISISAVE+CPUSAVE_R29)(%r1)
643	stw	%r31,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
644	lwz	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
645	stw	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
646	lwz	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
647	stw	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
648	mfdar	%r30
649	mfdsisr	%r31
650	stw	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
651	stw	%r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
652
653#ifdef KDB
654	/* Try and detect a kernel stack overflow */
655	mfsrr1	%r31
656	mtcr	%r31
657	bt	17,realtrap		/* branch is user mode */
658	mfsprg1	%r31			/* get old SP */
659	sub.	%r30,%r31,%r30		/* SP - DAR */
660	bge	1f
661	neg	%r30,%r30		/* modulo value */
6621:	cmplwi	%cr0,%r30,4096		/* is DAR within a page of SP? */
663	bge	%cr0,realtrap		/* no, too far away. */
664
665	/* Now convert this DSI into a DDB trap.  */
666	GET_CPUINFO(%r1)
667	lwz	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1) /* get DAR */
668	stw	%r30,(PC_DBSAVE  +CPUSAVE_AIM_DAR)(%r1) /* save DAR */
669	lwz	%r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1) /* get DSISR */
670	stw	%r31,(PC_DBSAVE  +CPUSAVE_AIM_DSISR)(%r1) /* save DSISR */
671	lwz	%r30,(PC_DISISAVE+CPUSAVE_R28)(%r1) /* get  r28 */
672	stw	%r30,(PC_DBSAVE  +CPUSAVE_R28)(%r1) /* save r28 */
673	lwz	%r31,(PC_DISISAVE+CPUSAVE_R29)(%r1) /* get  r29 */
674	stw	%r31,(PC_DBSAVE  +CPUSAVE_R29)(%r1) /* save r29 */
675	lwz	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1) /* get  r30 */
676	stw	%r30,(PC_DBSAVE  +CPUSAVE_R30)(%r1) /* save r30 */
677	lwz	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1) /* get  r31 */
678	stw	%r31,(PC_DBSAVE  +CPUSAVE_R31)(%r1) /* save r31 */
679	b	dbtrap
680#endif
681
682	/* XXX need stack probe here */
683realtrap:
684/* Test whether we already had PR set */
685	mfsrr1	%r1
686	mtcr	%r1
687	mfsprg1	%r1			/* restore SP (might have been
688					   overwritten) */
689	bf	17,k_trap		/* branch if PSL_PR is false */
690	GET_CPUINFO(%r1)
691	lwz	%r1,PC_CURPCB(%r1)
692	RESTORE_KERN_SRS(%r30,%r31)	/* enable kernel mapping */
693	ba s_trap
694
695/*
696 * generictrap does some standard setup for trap handling to minimize
697 * the code that need be installed in the actual vectors. It expects
698 * the following conditions.
699 *
700 * R1 - Trap vector = LR & (0xff00 | R1)
701 * SPRG1 - Original R1 contents
702 * SPRG2 - Original LR
703 */
704
705generictrap64:
706	mtsprg3	%r31
707	mfmsr	%r31
708	clrldi	%r31,%r31,1
709	mtmsrd	%r31
710	mfsprg3	%r31
711	isync
712
713generictrap:
714	/* Save R1 for computing the exception vector */
715	mtsprg3 %r1
716
717	/* Save interesting registers */
718	GET_CPUINFO(%r1)
719	stw	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)	/* free r28-r31 */
720	stw	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
721	stw	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
722	stw	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
723	mfsprg1	%r1			/* restore SP, in case of branch */
724	mfsprg2	%r28			/* save LR */
725	mfcr	%r29			/* save CR */
726
727	/* Compute the exception vector from the link register */
728	mfsprg3 %r31
729	ori	%r31,%r31,0xff00
730	mflr	%r30
731	and	%r30,%r30,%r31
732	mtsprg3	%r30
733
734	/* Test whether we already had PR set */
735	mfsrr1	%r31
736	mtcr	%r31
737
738s_trap:
739	bf	17,k_trap		/* branch if PSL_PR is false */
740	GET_CPUINFO(%r1)
741u_trap:
742	lwz	%r1,PC_CURPCB(%r1)
743	RESTORE_KERN_SRS(%r30,%r31)	/* enable kernel mapping */
744
745/*
746 * Now the common trap catching code.
747 */
748k_trap:
749	FRAME_SETUP(PC_TEMPSAVE)
750	/* Restore USER_SR */
751	GET_CPUINFO(%r30)
752	lwz	%r30,PC_CURPCB(%r30)
753	lwz	%r30,PCB_AIM_USR_VSID(%r30)
754	mtsr	USER_SR,%r30; sync; isync
755/* Call C interrupt dispatcher: */
756trapagain:
757	addi	%r3,%r1,8
758	bl	CNAME(powerpc_interrupt)
759	.globl	CNAME(trapexit)		/* backtrace code sentinel */
760CNAME(trapexit):
761
762/* Disable interrupts: */
763	mfmsr	%r3
764	andi.	%r3,%r3,~PSL_EE@l
765	mtmsr	%r3
766/* Test AST pending: */
767	lwz	%r5,FRAME_SRR1+8(%r1)
768	mtcr	%r5
769	bf	17,1f			/* branch if PSL_PR is false */
770
771	GET_CPUINFO(%r3)		/* get per-CPU pointer */
772	lwz	%r4, TD_FLAGS(%r2)	/* get thread flags value
773					 * (r2 is curthread) */
774	lis	%r5, (TDF_ASTPENDING|TDF_NEEDRESCHED)@h
775	ori	%r5,%r5, (TDF_ASTPENDING|TDF_NEEDRESCHED)@l
776	and.	%r4,%r4,%r5
777	beq	1f
778	mfmsr	%r3			/* re-enable interrupts */
779	ori	%r3,%r3,PSL_EE@l
780	mtmsr	%r3
781	isync
782	addi	%r3,%r1,8
783	bl	CNAME(ast)
784	.globl	CNAME(asttrapexit)	/* backtrace code sentinel #2 */
785CNAME(asttrapexit):
786	b	trapexit		/* test ast ret value ? */
7871:
788	FRAME_LEAVE(PC_TEMPSAVE)
789
790	.globl	CNAME(rfi_patch1)	/* replace rfi with rfid on ppc64 */
791CNAME(rfi_patch1):
792	rfi
793
794	.globl	CNAME(rfid_patch)
795CNAME(rfid_patch):
796	rfid
797
798#if defined(KDB)
799/*
800 * Deliberate entry to dbtrap
801 */
802	.globl	CNAME(breakpoint)
803CNAME(breakpoint):
804	mtsprg1	%r1
805	mfmsr	%r3
806	mtsrr1	%r3
807	andi.	%r3,%r3,~(PSL_EE|PSL_ME)@l
808	mtmsr	%r3			/* disable interrupts */
809	isync
810	GET_CPUINFO(%r3)
811	stw	%r28,(PC_DBSAVE+CPUSAVE_R28)(%r3)
812	stw	%r29,(PC_DBSAVE+CPUSAVE_R29)(%r3)
813	stw	%r30,(PC_DBSAVE+CPUSAVE_R30)(%r3)
814	stw	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r3)
815	mflr	%r28
816	li	%r29,EXC_BPT
817	mtlr	%r29
818	mfcr	%r29
819	mtsrr0	%r28
820
821/*
822 * Now the kdb trap catching code.
823 */
824dbtrap:
825	/* Write the trap vector to SPRG3 by computing LR & 0xff00 */
826	mflr	%r1
827	andi.	%r1,%r1,0xff00
828	mtsprg3	%r1
829
830	lis	%r1,(tmpstk+TMPSTKSZ-16)@ha	/* get new SP */
831	addi	%r1,%r1,(tmpstk+TMPSTKSZ-16)@l
832
833	FRAME_SETUP(PC_DBSAVE)
834/* Call C trap code: */
835	addi	%r3,%r1,8
836	bl	CNAME(db_trap_glue)
837	or.	%r3,%r3,%r3
838	bne	dbleave
839/* This wasn't for KDB, so switch to real trap: */
840	lwz	%r3,FRAME_EXC+8(%r1)	/* save exception */
841	GET_CPUINFO(%r4)
842	stw	%r3,(PC_DBSAVE+CPUSAVE_R31)(%r4)
843	FRAME_LEAVE(PC_DBSAVE)
844	mtsprg1	%r1			/* prepare for entrance to realtrap */
845	GET_CPUINFO(%r1)
846	stw	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
847	stw	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
848	stw	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
849	stw	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
850	mflr	%r28
851	mfcr	%r29
852	lwz	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r1)
853	mtsprg3	%r31			/* SPRG3 was clobbered by FRAME_LEAVE */
854	mfsprg1	%r1
855	b	realtrap
856dbleave:
857	FRAME_LEAVE(PC_DBSAVE)
858	.globl	CNAME(rfi_patch2)	/* replace rfi with rfid on ppc64 */
859CNAME(rfi_patch2):
860	rfi
861
862/*
863 * In case of KDB we want a separate trap catcher for it
864 */
865	.globl	CNAME(dblow),CNAME(dbsize)
866CNAME(dblow):
867	mtsprg1	%r1			/* save SP */
868	mtsprg2	%r29			/* save r29 */
869	mfcr	%r29			/* save CR in r29 */
870	mfsrr1	%r1
871	mtcr	%r1
872	bf	17,1f			/* branch if privileged */
873
874	/* Unprivileged case */
875	mtcr	%r29			/* put the condition register back */
876        mfsprg2	%r29			/* ... and r29 */
877        mflr	%r1			/* save LR */
878	mtsprg2 %r1			/* And then in SPRG2 */
879	li	%r1, 0	 		/* How to get the vector from LR */
880
881        bla     generictrap		/* and we look like a generic trap */
8821:
883	/* Privileged, so drop to KDB */
884	GET_CPUINFO(%r1)
885	stw	%r28,(PC_DBSAVE+CPUSAVE_R28)(%r1)	/* free r28 */
886        mfsprg2	%r28				/* r29 holds cr...  */
887        stw	%r28,(PC_DBSAVE+CPUSAVE_R29)(%r1)	/* free r29 */
888        stw	%r30,(PC_DBSAVE+CPUSAVE_R30)(%r1)	/* free r30 */
889        stw	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r1)	/* free r31 */
890        mflr	%r28					/* save LR */
891	bla	dbtrap
892CNAME(dbsize) = .-CNAME(dblow)
893#endif /* KDB */
894