1/* $FreeBSD: stable/9/sys/powerpc/aim/trap_subr32.S 223570 2011-06-26 15:08:14Z nwhitehorn $ */
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	bla	CNAME(pmap_cpu_bootstrap)
307	bla	CNAME(cpudep_ap_bootstrap)
308	mr	%r1,%r3
309	bla	CNAME(machdep_ap_bootstrap)
310
311	/* Should not be reached */
3129:
313	b	9b
314#endif
315
316/*
317 * This code gets copied to all the trap vectors
318 * (except ISI/DSI, ALI, and the interrupts)
319 */
320
321	.globl	CNAME(trapcode),CNAME(trapsize)
322CNAME(trapcode):
323	mtsprg1	%r1			/* save SP */
324	mflr	%r1			/* Save the old LR in r1 */
325	mtsprg2 %r1			/* And then in SPRG2 */
326	li	%r1, 0x20		/* How to get the vector from LR */
327	bla	generictrap		/* LR & SPRG3 is exception # */
328CNAME(trapsize) = .-CNAME(trapcode)
329
330/*
331 * 64-bit version of trapcode. Identical, except it calls generictrap64.
332 */
333	.globl	CNAME(trapcode64)
334CNAME(trapcode64):
335	mtsprg1	%r1			/* save SP */
336	mflr	%r1			/* Save the old LR in r1 */
337	mtsprg2 %r1			/* And then in SPRG2 */
338	li	%r1, 0x20		/* How to get the vector from LR */
339	bla	generictrap64		/* LR & SPRG3 is exception # */
340
341/*
342 * For ALI: has to save DSISR and DAR
343 */
344	.globl	CNAME(alitrap),CNAME(alisize)
345CNAME(alitrap):
346	mtsprg1	%r1			/* save SP */
347	GET_CPUINFO(%r1)
348	stw	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)	/* free r28-r31 */
349	stw	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
350	stw	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
351	stw	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
352	mfdar	%r30
353	mfdsisr	%r31
354	stw	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
355	stw	%r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
356	mfsprg1	%r1			/* restore SP, in case of branch */
357	mflr	%r28			/* save LR */
358	mfcr	%r29			/* save CR */
359
360	/* Put our exception vector in SPRG3 */
361	li	%r31, EXC_ALI
362	mtsprg3	%r31
363
364	/* Test whether we already had PR set */
365	mfsrr1	%r31
366	mtcr	%r31
367	bla	s_trap
368CNAME(alisize) = .-CNAME(alitrap)
369
370/*
371 * G2 specific: instuction TLB miss.
372 */
373	.globl	CNAME(imisstrap),CNAME(imisssize)
374CNAME(imisstrap):
375	mfspr %r2, SPR_HASH1		/* get first pointer */
376	addi %r1, 0, 8			/* load 8 for counter */
377	mfctr %r0			/* save counter */
378	mfspr %r3, SPR_ICMP		/* get first compare value */
379	addi %r2, %r2, -8		/* pre dec the pointer */
380im0:
381	mtctr %r1			/* load counter */
382im1:
383	lwzu %r1, 8(%r2)		/* get next pte */
384	cmp 0, %r1, %r3			/* see if found pte */
385	bdnzf 2, im1			/* dec count br if cmp ne and if
386					 * count not zero */
387	bne instr_sec_hash		/* if not found set up second hash
388					 * or exit */
389	lwz %r1, +4(%r2)		/* load tlb entry lower-word */
390	andi. %r3, %r1, 8		/* check G bit */
391	bne do_isi_prot			/* if guarded, take an ISI */
392	mtctr %r0			/* restore counter */
393	mfspr %r0, SPR_IMISS		/* get the miss address for the tlbli */
394	mfspr %r3, SPR_SRR1		/* get the saved cr0 bits */
395	mtcrf 0x80, %r3			/* restore CR0 */
396	mtspr SPR_RPA, %r1		/* set the pte */
397	ori %r1, %r1, 0x100		/* set reference bit */
398	srwi %r1, %r1, 8		/* get byte 7 of pte */
399	tlbli %r0 			/* load the itlb */
400	stb %r1, +6(%r2)		/* update page table */
401	rfi				/* return to executing program */
402
403instr_sec_hash:
404	andi. %r1, %r3, 0x0040		/* see if we have done second hash */
405	bne do_isi			/* if so, go to ISI interrupt */
406	mfspr %r2, SPR_HASH2		/* get the second pointer */
407	ori %r3, %r3, 0x0040		/* change the compare value */
408	addi %r1, %r0, 8		/* load 8 for counter */
409	addi %r2, %r2, -8		/* pre dec for update on load */
410	b im0				/* try second hash */
411
412/* Create a faked ISI interrupt as the address was not found */
413do_isi_prot:
414	mfspr %r3, SPR_SRR1		/* get srr1 */
415	andi. %r2, %r3, 0xffff		/* clean upper srr1 */
416	addis %r2, %r2, 0x0800		/* or in srr<4> = 1 to flag prot
417					 * violation */
418	b isi1
419do_isi:
420	mfspr %r3, SPR_SRR1		/* get srr1 */
421	andi. %r2, %r3, 0xffff		/* clean srr1 */
422	addis %r2, %r2, 0x4000		/* or in srr1<1> = 1 to flag pte
423					 * not found */
424isi1:
425	mtctr %r0			/* restore counter */
426	mtspr SPR_SRR1, %r2		/* set srr1 */
427	mfmsr %r0			/* get msr */
428	xoris %r0, %r0, 0x2		/* flip the msr<tgpr> bit */
429	mtcrf 0x80, %r3			/* restore CR0 */
430	mtmsr %r0			/* flip back to the native gprs */
431	ba EXC_ISI			/* go to instr. access interrupt */
432
433CNAME(imisssize) = .-CNAME(imisstrap)
434
435/*
436 * G2 specific: data load TLB miss.
437 */
438	.globl	CNAME(dlmisstrap),CNAME(dlmisssize)
439CNAME(dlmisstrap):
440	mfspr %r2, SPR_HASH1		/* get first pointer */
441	addi %r1, 0, 8			/* load 8 for counter */
442	mfctr %r0			/* save counter */
443	mfspr %r3, SPR_DCMP		/* get first compare value */
444	addi %r2, %r2, -8		/* pre dec the pointer */
445dm0:
446	mtctr %r1			/* load counter */
447dm1:
448	lwzu %r1, 8(%r2)		/* get next pte */
449	cmp 0, 0, %r1, %r3		/* see if found pte */
450	bdnzf 2, dm1			/* dec count br if cmp ne and if
451					 * count not zero */
452	bne data_sec_hash		/* if not found set up second hash
453					 * or exit */
454	lwz %r1, +4(%r2)		/* load tlb entry lower-word */
455	mtctr %r0			/* restore counter */
456	mfspr %r0, SPR_DMISS		/* get the miss address for the tlbld */
457	mfspr %r3, SPR_SRR1		/* get the saved cr0 bits */
458	mtcrf 0x80, %r3			/* restore CR0 */
459	mtspr SPR_RPA, %r1		/* set the pte */
460	ori %r1, %r1, 0x100		/* set reference bit */
461	srwi %r1, %r1, 8		/* get byte 7 of pte */
462	tlbld %r0			/* load the dtlb */
463	stb %r1, +6(%r2)		/* update page table */
464	rfi				/* return to executing program */
465
466data_sec_hash:
467	andi. %r1, %r3, 0x0040		/* see if we have done second hash */
468	bne do_dsi			/* if so, go to DSI interrupt */
469	mfspr %r2, SPR_HASH2		/* get the second pointer */
470	ori %r3, %r3, 0x0040		/* change the compare value */
471	addi %r1, 0, 8			/* load 8 for counter */
472	addi %r2, %r2, -8		/* pre dec for update on load */
473	b dm0				/* try second hash */
474
475CNAME(dlmisssize) = .-CNAME(dlmisstrap)
476
477/*
478 *  G2 specific: data store TLB miss.
479 */
480	.globl	CNAME(dsmisstrap),CNAME(dsmisssize)
481CNAME(dsmisstrap):
482	mfspr %r2, SPR_HASH1		/* get first pointer */
483	addi %r1, 0, 8			/* load 8 for counter */
484	mfctr %r0			/* save counter */
485	mfspr %r3, SPR_DCMP		/* get first compare value */
486	addi %r2, %r2, -8		/* pre dec the pointer */
487ds0:
488	mtctr %r1			/* load counter */
489ds1:
490	lwzu %r1, 8(%r2)		/* get next pte */
491	cmp 0, 0, %r1, %r3		/* see if found pte */
492	bdnzf 2, ds1			/* dec count br if cmp ne and if
493					 * count not zero */
494	bne data_store_sec_hash		/* if not found set up second hash
495					 * or exit */
496	lwz %r1, +4(%r2)		/* load tlb entry lower-word */
497	andi. %r3, %r1, 0x80		/* check the C-bit */
498	beq data_store_chk_prot		/* if (C==0)
499					 *     go check protection modes */
500ds2:
501	mtctr %r0			/* restore counter */
502	mfspr %r0, SPR_DMISS		/* get the miss address for the tlbld */
503	mfspr %r3, SPR_SRR1		/* get the saved cr0 bits */
504	mtcrf 0x80, %r3			/* restore CR0 */
505	mtspr SPR_RPA, %r1		/* set the pte */
506	tlbld %r0			/* load the dtlb */
507	rfi				/* return to executing program */
508
509data_store_sec_hash:
510	andi. %r1, %r3, 0x0040		/* see if we have done second hash */
511	bne do_dsi			/* if so, go to DSI interrupt */
512	mfspr %r2, SPR_HASH2		/* get the second pointer */
513	ori %r3, %r3, 0x0040		/* change the compare value */
514	addi %r1, 0, 8			/* load 8 for counter */
515	addi %r2, %r2, -8		/* pre dec for update on load */
516	b ds0				/* try second hash */
517
518/* Check the protection before setting PTE(c-bit) */
519data_store_chk_prot:
520	rlwinm. %r3,%r1,30,0,1		/* test PP */
521	bge- chk0			/* if (PP == 00 or PP == 01)
522					 *     goto chk0: */
523	andi. %r3, %r1, 1		/* test PP[0] */
524	beq+ chk2			/* return if PP[0] == 0 */
525	b do_dsi_prot			/* else DSIp */
526chk0:
527	mfspr %r3,SPR_SRR1		/* get old msr */
528	andis. %r3,%r3,0x0008		/* test the KEY bit (SRR1-bit 12) */
529	beq chk2			/* if (KEY==0) goto chk2: */
530	b do_dsi_prot			/* else do_dsi_prot */
531chk2:
532	ori %r1, %r1, 0x180		/* set reference and change bit */
533	sth %r1, 6(%r2)			/* update page table */
534	b ds2				/* and back we go */
535
536/* Create a faked DSI interrupt as the address was not found */
537do_dsi:
538	mfspr %r3, SPR_SRR1		/* get srr1 */
539	rlwinm %r1,%r3,9,6,6		/* get srr1<flag> to bit 6 for
540					 * load/store, zero rest */
541	addis %r1, %r1, 0x4000		/* or in dsisr<1> = 1 to flag pte
542					 * not found */
543	b dsi1
544
545do_dsi_prot:
546	mfspr %r3, SPR_SRR1		/* get srr1 */
547	rlwinm %r1,%r3,9,6,6		/* get srr1<flag> to bit 6 for
548					   *load/store, zero rest */
549	addis %r1, %r1, 0x0800		/* or in dsisr<4> = 1 to flag prot
550					 * violation */
551
552dsi1:
553	mtctr %r0			/* restore counter */
554	andi. %r2, %r3, 0xffff		/* clear upper bits of srr1 */
555	mtspr SPR_SRR1, %r2		/* set srr1 */
556	mtspr SPR_DSISR, %r1		/* load the dsisr */
557	mfspr %r1, SPR_DMISS		/* get miss address */
558	rlwinm. %r2,%r2,0,31,31		/* test LE bit */
559	beq dsi2			/* if little endian then: */
560	xor %r1, %r1, 0x07		/* de-mung the data address */
561dsi2:
562	mtspr SPR_DAR, %r1		/* put in dar */
563	mfmsr %r0			/* get msr */
564	xoris %r0, %r0, 0x2		/* flip the msr<tgpr> bit */
565	mtcrf 0x80, %r3			/* restore CR0 */
566	mtmsr %r0			/* flip back to the native gprs */
567	ba EXC_DSI			/* branch to DSI interrupt */
568
569CNAME(dsmisssize) = .-CNAME(dsmisstrap)
570
571/*
572 * Similar to the above for DSI
573 * Has to handle BAT spills
574 * and standard pagetable spills
575 */
576	.globl	CNAME(dsitrap),CNAME(dsisize)
577CNAME(dsitrap):
578	mtsprg1	%r1			/* save SP */
579	GET_CPUINFO(%r1)
580	stw	%r28,(PC_DISISAVE+CPUSAVE_R28)(%r1)	/* free r28-r31 */
581	stw	%r29,(PC_DISISAVE+CPUSAVE_R29)(%r1)
582	stw	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
583	stw	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
584	mfsprg1	%r1			/* restore SP */
585	mfcr	%r29			/* save CR */
586	mfxer	%r30			/* save XER */
587	mtsprg2	%r30			/* in SPRG2 */
588	mfsrr1	%r31			/* test kernel mode */
589	mtcr	%r31
590	bt	17,1f			/* branch if PSL_PR is set */
591	mfdar	%r31			/* get fault address */
592	rlwinm	%r31,%r31,7,25,28	/* get segment * 8 */
593
594	/* get batu */
595	addis	%r31,%r31,CNAME(battable)@ha
596	lwz	%r30,CNAME(battable)@l(31)
597	mtcr	%r30
598	bf	30,1f			/* branch if supervisor valid is
599					   false */
600	/* get batl */
601	lwz	%r31,CNAME(battable)+4@l(31)
602/* We randomly use the highest two bat registers here */
603	mftb	%r28
604	andi.	%r28,%r28,1
605	bne	2f
606	mtdbatu	2,%r30
607	mtdbatl	2,%r31
608	b	3f
6092:
610	mtdbatu	3,%r30
611	mtdbatl	3,%r31
6123:
613	mfsprg2	%r30			/* restore XER */
614	mtxer	%r30
615	mtcr	%r29			/* restore CR */
616	mtsprg1	%r1
617	GET_CPUINFO(%r1)
618	lwz	%r28,(PC_DISISAVE+CPUSAVE_R28)(%r1)	/* restore r28-r31 */
619	lwz	%r29,(PC_DISISAVE+CPUSAVE_R29)(%r1)
620	lwz	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
621	lwz	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
622	mfsprg1	%r1
623	rfi				/* return to trapped code */
6241:
625	mflr	%r28			/* save LR (SP already saved) */
626	bla	disitrap
627CNAME(dsisize) = .-CNAME(dsitrap)
628
629/*
630 * Preamble code for DSI/ISI traps
631 */
632disitrap:
633	/* Write the trap vector to SPRG3 by computing LR & 0xff00 */
634	mflr	%r1
635	andi.	%r1,%r1,0xff00
636	mtsprg3	%r1
637
638	GET_CPUINFO(%r1)
639	lwz	%r30,(PC_DISISAVE+CPUSAVE_R28)(%r1)
640	stw	%r30,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
641	lwz	%r31,(PC_DISISAVE+CPUSAVE_R29)(%r1)
642	stw	%r31,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
643	lwz	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
644	stw	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
645	lwz	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
646	stw	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
647	mfdar	%r30
648	mfdsisr	%r31
649	stw	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
650	stw	%r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
651
652#ifdef KDB
653	/* Try and detect a kernel stack overflow */
654	mfsrr1	%r31
655	mtcr	%r31
656	bt	17,realtrap		/* branch is user mode */
657	mfsprg1	%r31			/* get old SP */
658	sub.	%r30,%r31,%r30		/* SP - DAR */
659	bge	1f
660	neg	%r30,%r30		/* modulo value */
6611:	cmplwi	%cr0,%r30,4096		/* is DAR within a page of SP? */
662	bge	%cr0,realtrap		/* no, too far away. */
663
664	/* Now convert this DSI into a DDB trap.  */
665	GET_CPUINFO(%r1)
666	lwz	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1) /* get DAR */
667	stw	%r30,(PC_DBSAVE  +CPUSAVE_AIM_DAR)(%r1) /* save DAR */
668	lwz	%r30,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1) /* get DSISR */
669	stw	%r30,(PC_DBSAVE  +CPUSAVE_AIM_DSISR)(%r1) /* save DSISR */
670	lwz	%r30,(PC_DISISAVE+CPUSAVE_R28)(%r1) /* get  r28 */
671	stw	%r30,(PC_DBSAVE  +CPUSAVE_R28)(%r1) /* save r28 */
672	lwz	%r31,(PC_DISISAVE+CPUSAVE_R29)(%r1) /* get  r29 */
673	stw	%r31,(PC_DBSAVE  +CPUSAVE_R29)(%r1) /* save r29 */
674	lwz	%r30,(PC_DISISAVE+CPUSAVE_R30)(%r1) /* get  r30 */
675	stw	%r30,(PC_DBSAVE  +CPUSAVE_R30)(%r1) /* save r30 */
676	lwz	%r31,(PC_DISISAVE+CPUSAVE_R31)(%r1) /* get  r31 */
677	stw	%r31,(PC_DBSAVE  +CPUSAVE_R31)(%r1) /* save r31 */
678	b	dbtrap
679#endif
680
681	/* XXX need stack probe here */
682realtrap:
683/* Test whether we already had PR set */
684	mfsrr1	%r1
685	mtcr	%r1
686	mfsprg1	%r1			/* restore SP (might have been
687					   overwritten) */
688	bf	17,k_trap		/* branch if PSL_PR is false */
689	GET_CPUINFO(%r1)
690	lwz	%r1,PC_CURPCB(%r1)
691	RESTORE_KERN_SRS(%r30,%r31)	/* enable kernel mapping */
692	ba s_trap
693
694/*
695 * generictrap does some standard setup for trap handling to minimize
696 * the code that need be installed in the actual vectors. It expects
697 * the following conditions.
698 *
699 * R1 - Trap vector = LR & (0xff00 | R1)
700 * SPRG1 - Original R1 contents
701 * SPRG2 - Original LR
702 */
703
704generictrap64:
705	mtsprg3	%r31
706	mfmsr	%r31
707	clrldi	%r31,%r31,1
708	mtmsrd	%r31
709	mfsprg3	%r31
710	isync
711
712generictrap:
713	/* Save R1 for computing the exception vector */
714	mtsprg3 %r1
715
716	/* Save interesting registers */
717	GET_CPUINFO(%r1)
718	stw	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)	/* free r28-r31 */
719	stw	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
720	stw	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
721	stw	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
722	mfsprg1	%r1			/* restore SP, in case of branch */
723	mfsprg2	%r28			/* save LR */
724	mfcr	%r29			/* save CR */
725
726	/* Compute the exception vector from the link register */
727	mfsprg3 %r31
728	ori	%r31,%r31,0xff00
729	mflr	%r30
730	and	%r30,%r30,%r31
731	mtsprg3	%r30
732
733	/* Test whether we already had PR set */
734	mfsrr1	%r31
735	mtcr	%r31
736
737s_trap:
738	bf	17,k_trap		/* branch if PSL_PR is false */
739	GET_CPUINFO(%r1)
740u_trap:
741	lwz	%r1,PC_CURPCB(%r1)
742	RESTORE_KERN_SRS(%r30,%r31)	/* enable kernel mapping */
743
744/*
745 * Now the common trap catching code.
746 */
747k_trap:
748	FRAME_SETUP(PC_TEMPSAVE)
749	/* Restore USER_SR */
750	GET_CPUINFO(%r30)
751	lwz	%r30,PC_CURPCB(%r30)
752	lwz	%r30,PCB_AIM_USR_VSID(%r30)
753	mtsr	USER_SR,%r30; sync; isync
754/* Call C interrupt dispatcher: */
755trapagain:
756	addi	%r3,%r1,8
757	bl	CNAME(powerpc_interrupt)
758	.globl	CNAME(trapexit)		/* backtrace code sentinel */
759CNAME(trapexit):
760
761/* Disable interrupts: */
762	mfmsr	%r3
763	andi.	%r3,%r3,~PSL_EE@l
764	mtmsr	%r3
765/* Test AST pending: */
766	lwz	%r5,FRAME_SRR1+8(%r1)
767	mtcr	%r5
768	bf	17,1f			/* branch if PSL_PR is false */
769
770	GET_CPUINFO(%r3)		/* get per-CPU pointer */
771	lwz	%r4, TD_FLAGS(%r2)	/* get thread flags value
772					 * (r2 is curthread) */
773	lis	%r5, (TDF_ASTPENDING|TDF_NEEDRESCHED)@h
774	ori	%r5,%r5, (TDF_ASTPENDING|TDF_NEEDRESCHED)@l
775	and.	%r4,%r4,%r5
776	beq	1f
777	mfmsr	%r3			/* re-enable interrupts */
778	ori	%r3,%r3,PSL_EE@l
779	mtmsr	%r3
780	isync
781	addi	%r3,%r1,8
782	bl	CNAME(ast)
783	.globl	CNAME(asttrapexit)	/* backtrace code sentinel #2 */
784CNAME(asttrapexit):
785	b	trapexit		/* test ast ret value ? */
7861:
787	FRAME_LEAVE(PC_TEMPSAVE)
788
789	.globl	CNAME(rfi_patch1)	/* replace rfi with rfid on ppc64 */
790CNAME(rfi_patch1):
791	rfi
792
793	.globl	CNAME(rfid_patch)
794CNAME(rfid_patch):
795	rfid
796
797#if defined(KDB)
798/*
799 * Deliberate entry to dbtrap
800 */
801	.globl	CNAME(breakpoint)
802CNAME(breakpoint):
803	mtsprg1	%r1
804	mfmsr	%r3
805	mtsrr1	%r3
806	andi.	%r3,%r3,~(PSL_EE|PSL_ME)@l
807	mtmsr	%r3			/* disable interrupts */
808	isync
809	GET_CPUINFO(%r3)
810	stw	%r28,(PC_DBSAVE+CPUSAVE_R28)(%r3)
811	stw	%r29,(PC_DBSAVE+CPUSAVE_R29)(%r3)
812	stw	%r30,(PC_DBSAVE+CPUSAVE_R30)(%r3)
813	stw	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r3)
814	mflr	%r28
815	li	%r29,EXC_BPT
816	mtlr	%r29
817	mfcr	%r29
818	mtsrr0	%r28
819
820/*
821 * Now the kdb trap catching code.
822 */
823dbtrap:
824	/* Write the trap vector to SPRG3 by computing LR & 0xff00 */
825	mflr	%r1
826	andi.	%r1,%r1,0xff00
827	mtsprg3	%r1
828
829	lis	%r1,(tmpstk+TMPSTKSZ-16)@ha	/* get new SP */
830	addi	%r1,%r1,(tmpstk+TMPSTKSZ-16)@l
831
832	FRAME_SETUP(PC_DBSAVE)
833/* Call C trap code: */
834	addi	%r3,%r1,8
835	bl	CNAME(db_trap_glue)
836	or.	%r3,%r3,%r3
837	bne	dbleave
838/* This wasn't for KDB, so switch to real trap: */
839	lwz	%r3,FRAME_EXC+8(%r1)	/* save exception */
840	GET_CPUINFO(%r4)
841	stw	%r3,(PC_DBSAVE+CPUSAVE_R31)(%r4)
842	FRAME_LEAVE(PC_DBSAVE)
843	mtsprg1	%r1			/* prepare for entrance to realtrap */
844	GET_CPUINFO(%r1)
845	stw	%r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
846	stw	%r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
847	stw	%r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
848	stw	%r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
849	mflr	%r28
850	mfcr	%r29
851	lwz	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r1)
852	mtsprg3	%r31			/* SPRG3 was clobbered by FRAME_LEAVE */
853	mfsprg1	%r1
854	b	realtrap
855dbleave:
856	FRAME_LEAVE(PC_DBSAVE)
857	.globl	CNAME(rfi_patch2)	/* replace rfi with rfid on ppc64 */
858CNAME(rfi_patch2):
859	rfi
860
861/*
862 * In case of KDB we want a separate trap catcher for it
863 */
864	.globl	CNAME(dblow),CNAME(dbsize)
865CNAME(dblow):
866	mtsprg1	%r1			/* save SP */
867	mtsprg2	%r29			/* save r29 */
868	mfcr	%r29			/* save CR in r29 */
869	mfsrr1	%r1
870	mtcr	%r1
871	bf	17,1f			/* branch if privileged */
872
873	/* Unprivileged case */
874	mtcr	%r29			/* put the condition register back */
875        mfsprg2	%r29			/* ... and r29 */
876        mflr	%r1			/* save LR */
877	mtsprg2 %r1			/* And then in SPRG2 */
878	li	%r1, 0	 		/* How to get the vector from LR */
879
880        bla     generictrap		/* and we look like a generic trap */
8811:
882	/* Privileged, so drop to KDB */
883	GET_CPUINFO(%r1)
884	stw	%r28,(PC_DBSAVE+CPUSAVE_R28)(%r1)	/* free r28 */
885        mfsprg2	%r28				/* r29 holds cr...  */
886        stw	%r28,(PC_DBSAVE+CPUSAVE_R29)(%r1)	/* free r29 */
887        stw	%r30,(PC_DBSAVE+CPUSAVE_R30)(%r1)	/* free r30 */
888        stw	%r31,(PC_DBSAVE+CPUSAVE_R31)(%r1)	/* free r31 */
889        mflr	%r28					/* save LR */
890	bla	dbtrap
891CNAME(dbsize) = .-CNAME(dblow)
892#endif /* KDB */
893