1/*
2 * This file contains the 64-bit "server" PowerPC variant
3 * of the low level exception handling including exception
4 * vectors, exception return, part of the slb and stab
5 * handling and other fixed offset specific things.
6 *
7 * This file is meant to be #included from head_64.S due to
8 * position dependant assembly.
9 *
10 * Most of this originates from head_64.S and thus has the same
11 * copyright history.
12 *
13 */
14
15#include <asm/exception-64s.h>
16
17/*
18 * We layout physical memory as follows:
19 * 0x0000 - 0x00ff : Secondary processor spin code
20 * 0x0100 - 0x2fff : pSeries Interrupt prologs
21 * 0x3000 - 0x5fff : interrupt support, iSeries and common interrupt prologs
22 * 0x6000 - 0x6fff : Initial (CPU0) segment table
23 * 0x7000 - 0x7fff : FWNMI data area
24 * 0x8000 -        : Early init and support code
25 */
26
27/*
28 * This is the start of the interrupt handlers for pSeries
29 * This code runs with relocation off.
30 * Code from here to __end_interrupts gets copied down to real
31 * address 0x100 when we are running a relocatable kernel.
32 * Therefore any relative branches in this section must only
33 * branch to labels in this section.
34 */
35	. = 0x100
36	.globl __start_interrupts
37__start_interrupts:
38
39	STD_EXCEPTION_PSERIES(0x100, system_reset)
40
41	. = 0x200
42_machine_check_pSeries:
43	HMT_MEDIUM
44	mtspr	SPRN_SPRG_SCRATCH0,r13		/* save r13 */
45	EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)
46
47	. = 0x300
48	.globl data_access_pSeries
49data_access_pSeries:
50	HMT_MEDIUM
51	mtspr	SPRN_SPRG_SCRATCH0,r13
52BEGIN_FTR_SECTION
53	mfspr	r13,SPRN_SPRG_PACA
54	std	r9,PACA_EXSLB+EX_R9(r13)
55	std	r10,PACA_EXSLB+EX_R10(r13)
56	mfspr	r10,SPRN_DAR
57	mfspr	r9,SPRN_DSISR
58	srdi	r10,r10,60
59	rlwimi	r10,r9,16,0x20
60	mfcr	r9
61	cmpwi	r10,0x2c
62	beq	do_stab_bolted_pSeries
63	ld	r10,PACA_EXSLB+EX_R10(r13)
64	std	r11,PACA_EXGEN+EX_R11(r13)
65	ld	r11,PACA_EXSLB+EX_R9(r13)
66	std	r12,PACA_EXGEN+EX_R12(r13)
67	mfspr	r12,SPRN_SPRG_SCRATCH0
68	std	r10,PACA_EXGEN+EX_R10(r13)
69	std	r11,PACA_EXGEN+EX_R9(r13)
70	std	r12,PACA_EXGEN+EX_R13(r13)
71	EXCEPTION_PROLOG_PSERIES_1(data_access_common)
72FTR_SECTION_ELSE
73	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, data_access_common)
74ALT_FTR_SECTION_END_IFCLR(CPU_FTR_SLB)
75
76	. = 0x380
77	.globl data_access_slb_pSeries
78data_access_slb_pSeries:
79	HMT_MEDIUM
80	mtspr	SPRN_SPRG_SCRATCH0,r13
81	mfspr	r13,SPRN_SPRG_PACA		/* get paca address into r13 */
82	std	r3,PACA_EXSLB+EX_R3(r13)
83	mfspr	r3,SPRN_DAR
84	std	r9,PACA_EXSLB+EX_R9(r13)	/* save r9 - r12 */
85	mfcr	r9
86#ifdef __DISABLED__
87	/* Keep that around for when we re-implement dynamic VSIDs */
88	cmpdi	r3,0
89	bge	slb_miss_user_pseries
90#endif /* __DISABLED__ */
91	std	r10,PACA_EXSLB+EX_R10(r13)
92	std	r11,PACA_EXSLB+EX_R11(r13)
93	std	r12,PACA_EXSLB+EX_R12(r13)
94	mfspr	r10,SPRN_SPRG_SCRATCH0
95	std	r10,PACA_EXSLB+EX_R13(r13)
96	mfspr	r12,SPRN_SRR1		/* and SRR1 */
97#ifndef CONFIG_RELOCATABLE
98	b	.slb_miss_realmode
99#else
100	/*
101	 * We can't just use a direct branch to .slb_miss_realmode
102	 * because the distance from here to there depends on where
103	 * the kernel ends up being put.
104	 */
105	mfctr	r11
106	ld	r10,PACAKBASE(r13)
107	LOAD_HANDLER(r10, .slb_miss_realmode)
108	mtctr	r10
109	bctr
110#endif
111
112	STD_EXCEPTION_PSERIES(0x400, instruction_access)
113
114	. = 0x480
115	.globl instruction_access_slb_pSeries
116instruction_access_slb_pSeries:
117	HMT_MEDIUM
118	mtspr	SPRN_SPRG_SCRATCH0,r13
119	mfspr	r13,SPRN_SPRG_PACA		/* get paca address into r13 */
120	std	r3,PACA_EXSLB+EX_R3(r13)
121	mfspr	r3,SPRN_SRR0		/* SRR0 is faulting address */
122	std	r9,PACA_EXSLB+EX_R9(r13)	/* save r9 - r12 */
123	mfcr	r9
124#ifdef __DISABLED__
125	/* Keep that around for when we re-implement dynamic VSIDs */
126	cmpdi	r3,0
127	bge	slb_miss_user_pseries
128#endif /* __DISABLED__ */
129	std	r10,PACA_EXSLB+EX_R10(r13)
130	std	r11,PACA_EXSLB+EX_R11(r13)
131	std	r12,PACA_EXSLB+EX_R12(r13)
132	mfspr	r10,SPRN_SPRG_SCRATCH0
133	std	r10,PACA_EXSLB+EX_R13(r13)
134	mfspr	r12,SPRN_SRR1		/* and SRR1 */
135#ifndef CONFIG_RELOCATABLE
136	b	.slb_miss_realmode
137#else
138	mfctr	r11
139	ld	r10,PACAKBASE(r13)
140	LOAD_HANDLER(r10, .slb_miss_realmode)
141	mtctr	r10
142	bctr
143#endif
144
145	MASKABLE_EXCEPTION_PSERIES(0x500, hardware_interrupt)
146	STD_EXCEPTION_PSERIES(0x600, alignment)
147	STD_EXCEPTION_PSERIES(0x700, program_check)
148	STD_EXCEPTION_PSERIES(0x800, fp_unavailable)
149	MASKABLE_EXCEPTION_PSERIES(0x900, decrementer)
150	STD_EXCEPTION_PSERIES(0xa00, trap_0a)
151	STD_EXCEPTION_PSERIES(0xb00, trap_0b)
152
153	. = 0xc00
154	.globl	system_call_pSeries
155system_call_pSeries:
156	HMT_MEDIUM
157BEGIN_FTR_SECTION
158	cmpdi	r0,0x1ebe
159	beq-	1f
160END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
161	mr	r9,r13
162	mfspr	r13,SPRN_SPRG_PACA
163	mfspr	r11,SPRN_SRR0
164	ld	r12,PACAKBASE(r13)
165	ld	r10,PACAKMSR(r13)
166	LOAD_HANDLER(r12, system_call_entry)
167	mtspr	SPRN_SRR0,r12
168	mfspr	r12,SPRN_SRR1
169	mtspr	SPRN_SRR1,r10
170	rfid
171	b	.	/* prevent speculative execution */
172
173/* Fast LE/BE switch system call */
1741:	mfspr	r12,SPRN_SRR1
175	xori	r12,r12,MSR_LE
176	mtspr	SPRN_SRR1,r12
177	rfid		/* return to userspace */
178	b	.
179
180	STD_EXCEPTION_PSERIES(0xd00, single_step)
181	STD_EXCEPTION_PSERIES(0xe00, trap_0e)
182
183	/* We need to deal with the Altivec unavailable exception
184	 * here which is at 0xf20, thus in the middle of the
185	 * prolog code of the PerformanceMonitor one. A little
186	 * trickery is thus necessary
187	 */
188	. = 0xf00
189	b	performance_monitor_pSeries
190
191	. = 0xf20
192	b	altivec_unavailable_pSeries
193
194	. = 0xf40
195	b	vsx_unavailable_pSeries
196
197#ifdef CONFIG_CBE_RAS
198	HSTD_EXCEPTION_PSERIES(0x1200, cbe_system_error)
199#endif /* CONFIG_CBE_RAS */
200	STD_EXCEPTION_PSERIES(0x1300, instruction_breakpoint)
201#ifdef CONFIG_CBE_RAS
202	HSTD_EXCEPTION_PSERIES(0x1600, cbe_maintenance)
203#endif /* CONFIG_CBE_RAS */
204	STD_EXCEPTION_PSERIES(0x1700, altivec_assist)
205#ifdef CONFIG_CBE_RAS
206	HSTD_EXCEPTION_PSERIES(0x1800, cbe_thermal)
207#endif /* CONFIG_CBE_RAS */
208
209	. = 0x3000
210
211/*** pSeries interrupt support ***/
212
213	/* moved from 0xf00 */
214	STD_EXCEPTION_PSERIES(., performance_monitor)
215	STD_EXCEPTION_PSERIES(., altivec_unavailable)
216	STD_EXCEPTION_PSERIES(., vsx_unavailable)
217
218/*
219 * An interrupt came in while soft-disabled; clear EE in SRR1,
220 * clear paca->hard_enabled and return.
221 */
222masked_interrupt:
223	stb	r10,PACAHARDIRQEN(r13)
224	mtcrf	0x80,r9
225	ld	r9,PACA_EXGEN+EX_R9(r13)
226	mfspr	r10,SPRN_SRR1
227	rldicl	r10,r10,48,1		/* clear MSR_EE */
228	rotldi	r10,r10,16
229	mtspr	SPRN_SRR1,r10
230	ld	r10,PACA_EXGEN+EX_R10(r13)
231	mfspr	r13,SPRN_SPRG_SCRATCH0
232	rfid
233	b	.
234
235	.align	7
236do_stab_bolted_pSeries:
237	std	r11,PACA_EXSLB+EX_R11(r13)
238	std	r12,PACA_EXSLB+EX_R12(r13)
239	mfspr	r10,SPRN_SPRG_SCRATCH0
240	std	r10,PACA_EXSLB+EX_R13(r13)
241	EXCEPTION_PROLOG_PSERIES_1(.do_stab_bolted)
242
243#ifdef CONFIG_PPC_PSERIES
244/*
245 * Vectors for the FWNMI option.  Share common code.
246 */
247	.globl system_reset_fwnmi
248      .align 7
249system_reset_fwnmi:
250	HMT_MEDIUM
251	mtspr	SPRN_SPRG_SCRATCH0,r13		/* save r13 */
252	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common)
253
254	.globl machine_check_fwnmi
255      .align 7
256machine_check_fwnmi:
257	HMT_MEDIUM
258	mtspr	SPRN_SPRG_SCRATCH0,r13		/* save r13 */
259	EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)
260
261#endif /* CONFIG_PPC_PSERIES */
262
263#ifdef __DISABLED__
264/*
265 * This is used for when the SLB miss handler has to go virtual,
266 * which doesn't happen for now anymore but will once we re-implement
267 * dynamic VSIDs for shared page tables
268 */
269slb_miss_user_pseries:
270	std	r10,PACA_EXGEN+EX_R10(r13)
271	std	r11,PACA_EXGEN+EX_R11(r13)
272	std	r12,PACA_EXGEN+EX_R12(r13)
273	mfspr	r10,SPRG_SCRATCH0
274	ld	r11,PACA_EXSLB+EX_R9(r13)
275	ld	r12,PACA_EXSLB+EX_R3(r13)
276	std	r10,PACA_EXGEN+EX_R13(r13)
277	std	r11,PACA_EXGEN+EX_R9(r13)
278	std	r12,PACA_EXGEN+EX_R3(r13)
279	clrrdi	r12,r13,32
280	mfmsr	r10
281	mfspr	r11,SRR0			/* save SRR0 */
282	ori	r12,r12,slb_miss_user_common@l	/* virt addr of handler */
283	ori	r10,r10,MSR_IR|MSR_DR|MSR_RI
284	mtspr	SRR0,r12
285	mfspr	r12,SRR1			/* and SRR1 */
286	mtspr	SRR1,r10
287	rfid
288	b	.				/* prevent spec. execution */
289#endif /* __DISABLED__ */
290
291	.align	7
292	.globl	__end_interrupts
293__end_interrupts:
294
295/*
296 * Code from here down to __end_handlers is invoked from the
297 * exception prologs above.  Because the prologs assemble the
298 * addresses of these handlers using the LOAD_HANDLER macro,
299 * which uses an addi instruction, these handlers must be in
300 * the first 32k of the kernel image.
301 */
302
303/*** Common interrupt handlers ***/
304
305	STD_EXCEPTION_COMMON(0x100, system_reset, .system_reset_exception)
306
307	/*
308	 * Machine check is different because we use a different
309	 * save area: PACA_EXMC instead of PACA_EXGEN.
310	 */
311	.align	7
312	.globl machine_check_common
313machine_check_common:
314	EXCEPTION_PROLOG_COMMON(0x200, PACA_EXMC)
315	FINISH_NAP
316	DISABLE_INTS
317	bl	.save_nvgprs
318	addi	r3,r1,STACK_FRAME_OVERHEAD
319	bl	.machine_check_exception
320	b	.ret_from_except
321
322	STD_EXCEPTION_COMMON_LITE(0x900, decrementer, .timer_interrupt)
323	STD_EXCEPTION_COMMON(0xa00, trap_0a, .unknown_exception)
324	STD_EXCEPTION_COMMON(0xb00, trap_0b, .unknown_exception)
325	STD_EXCEPTION_COMMON(0xd00, single_step, .single_step_exception)
326	STD_EXCEPTION_COMMON(0xe00, trap_0e, .unknown_exception)
327	STD_EXCEPTION_COMMON_IDLE(0xf00, performance_monitor, .performance_monitor_exception)
328	STD_EXCEPTION_COMMON(0x1300, instruction_breakpoint, .instruction_breakpoint_exception)
329#ifdef CONFIG_ALTIVEC
330	STD_EXCEPTION_COMMON(0x1700, altivec_assist, .altivec_assist_exception)
331#else
332	STD_EXCEPTION_COMMON(0x1700, altivec_assist, .unknown_exception)
333#endif
334#ifdef CONFIG_CBE_RAS
335	STD_EXCEPTION_COMMON(0x1200, cbe_system_error, .cbe_system_error_exception)
336	STD_EXCEPTION_COMMON(0x1600, cbe_maintenance, .cbe_maintenance_exception)
337	STD_EXCEPTION_COMMON(0x1800, cbe_thermal, .cbe_thermal_exception)
338#endif /* CONFIG_CBE_RAS */
339
340	.align	7
341system_call_entry:
342	b	system_call_common
343
344/*
345 * Here we have detected that the kernel stack pointer is bad.
346 * R9 contains the saved CR, r13 points to the paca,
347 * r10 contains the (bad) kernel stack pointer,
348 * r11 and r12 contain the saved SRR0 and SRR1.
349 * We switch to using an emergency stack, save the registers there,
350 * and call kernel_bad_stack(), which panics.
351 */
352bad_stack:
353	ld	r1,PACAEMERGSP(r13)
354	subi	r1,r1,64+INT_FRAME_SIZE
355	std	r9,_CCR(r1)
356	std	r10,GPR1(r1)
357	std	r11,_NIP(r1)
358	std	r12,_MSR(r1)
359	mfspr	r11,SPRN_DAR
360	mfspr	r12,SPRN_DSISR
361	std	r11,_DAR(r1)
362	std	r12,_DSISR(r1)
363	mflr	r10
364	mfctr	r11
365	mfxer	r12
366	std	r10,_LINK(r1)
367	std	r11,_CTR(r1)
368	std	r12,_XER(r1)
369	SAVE_GPR(0,r1)
370	SAVE_GPR(2,r1)
371	SAVE_4GPRS(3,r1)
372	SAVE_2GPRS(7,r1)
373	SAVE_10GPRS(12,r1)
374	SAVE_10GPRS(22,r1)
375	lhz	r12,PACA_TRAP_SAVE(r13)
376	std	r12,_TRAP(r1)
377	addi	r11,r1,INT_FRAME_SIZE
378	std	r11,0(r1)
379	li	r12,0
380	std	r12,0(r11)
381	ld	r2,PACATOC(r13)
3821:	addi	r3,r1,STACK_FRAME_OVERHEAD
383	bl	.kernel_bad_stack
384	b	1b
385
386/*
387 * Here r13 points to the paca, r9 contains the saved CR,
388 * SRR0 and SRR1 are saved in r11 and r12,
389 * r9 - r13 are saved in paca->exgen.
390 */
391	.align	7
392	.globl data_access_common
393data_access_common:
394	mfspr	r10,SPRN_DAR
395	std	r10,PACA_EXGEN+EX_DAR(r13)
396	mfspr	r10,SPRN_DSISR
397	stw	r10,PACA_EXGEN+EX_DSISR(r13)
398	EXCEPTION_PROLOG_COMMON(0x300, PACA_EXGEN)
399	ld	r3,PACA_EXGEN+EX_DAR(r13)
400	lwz	r4,PACA_EXGEN+EX_DSISR(r13)
401	li	r5,0x300
402	b	.do_hash_page	 	/* Try to handle as hpte fault */
403
404	.align	7
405	.globl instruction_access_common
406instruction_access_common:
407	EXCEPTION_PROLOG_COMMON(0x400, PACA_EXGEN)
408	ld	r3,_NIP(r1)
409	andis.	r4,r12,0x5820
410	li	r5,0x400
411	b	.do_hash_page		/* Try to handle as hpte fault */
412
413/*
414 * Here is the common SLB miss user that is used when going to virtual
415 * mode for SLB misses, that is currently not used
416 */
417#ifdef __DISABLED__
418	.align	7
419	.globl	slb_miss_user_common
420slb_miss_user_common:
421	mflr	r10
422	std	r3,PACA_EXGEN+EX_DAR(r13)
423	stw	r9,PACA_EXGEN+EX_CCR(r13)
424	std	r10,PACA_EXGEN+EX_LR(r13)
425	std	r11,PACA_EXGEN+EX_SRR0(r13)
426	bl	.slb_allocate_user
427
428	ld	r10,PACA_EXGEN+EX_LR(r13)
429	ld	r3,PACA_EXGEN+EX_R3(r13)
430	lwz	r9,PACA_EXGEN+EX_CCR(r13)
431	ld	r11,PACA_EXGEN+EX_SRR0(r13)
432	mtlr	r10
433	beq-	slb_miss_fault
434
435	andi.	r10,r12,MSR_RI		/* check for unrecoverable exception */
436	beq-	unrecov_user_slb
437	mfmsr	r10
438
439.machine push
440.machine "power4"
441	mtcrf	0x80,r9
442.machine pop
443
444	clrrdi	r10,r10,2		/* clear RI before setting SRR0/1 */
445	mtmsrd	r10,1
446
447	mtspr	SRR0,r11
448	mtspr	SRR1,r12
449
450	ld	r9,PACA_EXGEN+EX_R9(r13)
451	ld	r10,PACA_EXGEN+EX_R10(r13)
452	ld	r11,PACA_EXGEN+EX_R11(r13)
453	ld	r12,PACA_EXGEN+EX_R12(r13)
454	ld	r13,PACA_EXGEN+EX_R13(r13)
455	rfid
456	b	.
457
458slb_miss_fault:
459	EXCEPTION_PROLOG_COMMON(0x380, PACA_EXGEN)
460	ld	r4,PACA_EXGEN+EX_DAR(r13)
461	li	r5,0
462	std	r4,_DAR(r1)
463	std	r5,_DSISR(r1)
464	b	handle_page_fault
465
466unrecov_user_slb:
467	EXCEPTION_PROLOG_COMMON(0x4200, PACA_EXGEN)
468	DISABLE_INTS
469	bl	.save_nvgprs
4701:	addi	r3,r1,STACK_FRAME_OVERHEAD
471	bl	.unrecoverable_exception
472	b	1b
473
474#endif /* __DISABLED__ */
475
476
477/*
478 * r13 points to the PACA, r9 contains the saved CR,
479 * r12 contain the saved SRR1, SRR0 is still ready for return
480 * r3 has the faulting address
481 * r9 - r13 are saved in paca->exslb.
482 * r3 is saved in paca->slb_r3
483 * We assume we aren't going to take any exceptions during this procedure.
484 */
485_GLOBAL(slb_miss_realmode)
486	mflr	r10
487#ifdef CONFIG_RELOCATABLE
488	mtctr	r11
489#endif
490
491	stw	r9,PACA_EXSLB+EX_CCR(r13)	/* save CR in exc. frame */
492	std	r10,PACA_EXSLB+EX_LR(r13)	/* save LR */
493
494	bl	.slb_allocate_realmode
495
496	/* All done -- return from exception. */
497
498	ld	r10,PACA_EXSLB+EX_LR(r13)
499	ld	r3,PACA_EXSLB+EX_R3(r13)
500	lwz	r9,PACA_EXSLB+EX_CCR(r13)	/* get saved CR */
501#ifdef CONFIG_PPC_ISERIES
502BEGIN_FW_FTR_SECTION
503	ld	r11,PACALPPACAPTR(r13)
504	ld	r11,LPPACASRR0(r11)		/* get SRR0 value */
505END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
506#endif /* CONFIG_PPC_ISERIES */
507
508	mtlr	r10
509
510	andi.	r10,r12,MSR_RI	/* check for unrecoverable exception */
511	beq-	2f
512
513.machine	push
514.machine	"power4"
515	mtcrf	0x80,r9
516	mtcrf	0x01,r9		/* slb_allocate uses cr0 and cr7 */
517.machine	pop
518
519#ifdef CONFIG_PPC_ISERIES
520BEGIN_FW_FTR_SECTION
521	mtspr	SPRN_SRR0,r11
522	mtspr	SPRN_SRR1,r12
523END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
524#endif /* CONFIG_PPC_ISERIES */
525	ld	r9,PACA_EXSLB+EX_R9(r13)
526	ld	r10,PACA_EXSLB+EX_R10(r13)
527	ld	r11,PACA_EXSLB+EX_R11(r13)
528	ld	r12,PACA_EXSLB+EX_R12(r13)
529	ld	r13,PACA_EXSLB+EX_R13(r13)
530	rfid
531	b	.	/* prevent speculative execution */
532
5332:
534#ifdef CONFIG_PPC_ISERIES
535BEGIN_FW_FTR_SECTION
536	b	unrecov_slb
537END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
538#endif /* CONFIG_PPC_ISERIES */
539	mfspr	r11,SPRN_SRR0
540	ld	r10,PACAKBASE(r13)
541	LOAD_HANDLER(r10,unrecov_slb)
542	mtspr	SPRN_SRR0,r10
543	ld	r10,PACAKMSR(r13)
544	mtspr	SPRN_SRR1,r10
545	rfid
546	b	.
547
548unrecov_slb:
549	EXCEPTION_PROLOG_COMMON(0x4100, PACA_EXSLB)
550	DISABLE_INTS
551	bl	.save_nvgprs
5521:	addi	r3,r1,STACK_FRAME_OVERHEAD
553	bl	.unrecoverable_exception
554	b	1b
555
556	.align	7
557	.globl hardware_interrupt_common
558	.globl hardware_interrupt_entry
559hardware_interrupt_common:
560	EXCEPTION_PROLOG_COMMON(0x500, PACA_EXGEN)
561	FINISH_NAP
562hardware_interrupt_entry:
563	DISABLE_INTS
564BEGIN_FTR_SECTION
565	bl	.ppc64_runlatch_on
566END_FTR_SECTION_IFSET(CPU_FTR_CTRL)
567	addi	r3,r1,STACK_FRAME_OVERHEAD
568	bl	.do_IRQ
569	b	.ret_from_except_lite
570
571#ifdef CONFIG_PPC_970_NAP
572power4_fixup_nap:
573	andc	r9,r9,r10
574	std	r9,TI_LOCAL_FLAGS(r11)
575	ld	r10,_LINK(r1)		/* make idle task do the */
576	std	r10,_NIP(r1)		/* equivalent of a blr */
577	blr
578#endif
579
580	.align	7
581	.globl alignment_common
582alignment_common:
583	mfspr	r10,SPRN_DAR
584	std	r10,PACA_EXGEN+EX_DAR(r13)
585	mfspr	r10,SPRN_DSISR
586	stw	r10,PACA_EXGEN+EX_DSISR(r13)
587	EXCEPTION_PROLOG_COMMON(0x600, PACA_EXGEN)
588	ld	r3,PACA_EXGEN+EX_DAR(r13)
589	lwz	r4,PACA_EXGEN+EX_DSISR(r13)
590	std	r3,_DAR(r1)
591	std	r4,_DSISR(r1)
592	bl	.save_nvgprs
593	addi	r3,r1,STACK_FRAME_OVERHEAD
594	ENABLE_INTS
595	bl	.alignment_exception
596	b	.ret_from_except
597
598	.align	7
599	.globl program_check_common
600program_check_common:
601	EXCEPTION_PROLOG_COMMON(0x700, PACA_EXGEN)
602	bl	.save_nvgprs
603	addi	r3,r1,STACK_FRAME_OVERHEAD
604	ENABLE_INTS
605	bl	.program_check_exception
606	b	.ret_from_except
607
608	.align	7
609	.globl fp_unavailable_common
610fp_unavailable_common:
611	EXCEPTION_PROLOG_COMMON(0x800, PACA_EXGEN)
612	bne	1f			/* if from user, just load it up */
613	bl	.save_nvgprs
614	addi	r3,r1,STACK_FRAME_OVERHEAD
615	ENABLE_INTS
616	bl	.kernel_fp_unavailable_exception
617	BUG_OPCODE
6181:	bl	.load_up_fpu
619	b	fast_exception_return
620
621	.align	7
622	.globl altivec_unavailable_common
623altivec_unavailable_common:
624	EXCEPTION_PROLOG_COMMON(0xf20, PACA_EXGEN)
625#ifdef CONFIG_ALTIVEC
626BEGIN_FTR_SECTION
627	beq	1f
628	bl	.load_up_altivec
629	b	fast_exception_return
6301:
631END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
632#endif
633	bl	.save_nvgprs
634	addi	r3,r1,STACK_FRAME_OVERHEAD
635	ENABLE_INTS
636	bl	.altivec_unavailable_exception
637	b	.ret_from_except
638
639	.align	7
640	.globl vsx_unavailable_common
641vsx_unavailable_common:
642	EXCEPTION_PROLOG_COMMON(0xf40, PACA_EXGEN)
643#ifdef CONFIG_VSX
644BEGIN_FTR_SECTION
645	bne	.load_up_vsx
6461:
647END_FTR_SECTION_IFSET(CPU_FTR_VSX)
648#endif
649	bl	.save_nvgprs
650	addi	r3,r1,STACK_FRAME_OVERHEAD
651	ENABLE_INTS
652	bl	.vsx_unavailable_exception
653	b	.ret_from_except
654
655	.align	7
656	.globl	__end_handlers
657__end_handlers:
658
659/*
660 * Return from an exception with minimal checks.
661 * The caller is assumed to have done EXCEPTION_PROLOG_COMMON.
662 * If interrupts have been enabled, or anything has been
663 * done that might have changed the scheduling status of
664 * any task or sent any task a signal, you should use
665 * ret_from_except or ret_from_except_lite instead of this.
666 */
667fast_exc_return_irq:			/* restores irq state too */
668	ld	r3,SOFTE(r1)
669	TRACE_AND_RESTORE_IRQ(r3);
670	ld	r12,_MSR(r1)
671	rldicl	r4,r12,49,63		/* get MSR_EE to LSB */
672	stb	r4,PACAHARDIRQEN(r13)	/* restore paca->hard_enabled */
673	b	1f
674
675	.globl	fast_exception_return
676fast_exception_return:
677	ld	r12,_MSR(r1)
6781:	ld	r11,_NIP(r1)
679	andi.	r3,r12,MSR_RI		/* check if RI is set */
680	beq-	unrecov_fer
681
682#ifdef CONFIG_VIRT_CPU_ACCOUNTING
683	andi.	r3,r12,MSR_PR
684	beq	2f
685	ACCOUNT_CPU_USER_EXIT(r3, r4)
6862:
687#endif
688
689	ld	r3,_CCR(r1)
690	ld	r4,_LINK(r1)
691	ld	r5,_CTR(r1)
692	ld	r6,_XER(r1)
693	mtcr	r3
694	mtlr	r4
695	mtctr	r5
696	mtxer	r6
697	REST_GPR(0, r1)
698	REST_8GPRS(2, r1)
699
700	mfmsr	r10
701	rldicl	r10,r10,48,1		/* clear EE */
702	rldicr	r10,r10,16,61		/* clear RI (LE is 0 already) */
703	mtmsrd	r10,1
704
705	mtspr	SPRN_SRR1,r12
706	mtspr	SPRN_SRR0,r11
707	REST_4GPRS(10, r1)
708	ld	r1,GPR1(r1)
709	rfid
710	b	.	/* prevent speculative execution */
711
712unrecov_fer:
713	bl	.save_nvgprs
7141:	addi	r3,r1,STACK_FRAME_OVERHEAD
715	bl	.unrecoverable_exception
716	b	1b
717
718
719/*
720 * Hash table stuff
721 */
722	.align	7
723_STATIC(do_hash_page)
724	std	r3,_DAR(r1)
725	std	r4,_DSISR(r1)
726
727	andis.	r0,r4,0xa450		/* weird error? */
728	bne-	handle_page_fault	/* if not, try to insert a HPTE */
729BEGIN_FTR_SECTION
730	andis.	r0,r4,0x0020		/* Is it a segment table fault? */
731	bne-	do_ste_alloc		/* If so handle it */
732END_FTR_SECTION_IFCLR(CPU_FTR_SLB)
733
734	clrrdi	r11,r1,THREAD_SHIFT
735	lwz	r0,TI_PREEMPT(r11)	/* If we're in an "NMI" */
736	andis.	r0,r0,NMI_MASK@h	/* (i.e. an irq when soft-disabled) */
737	bne	77f			/* then don't call hash_page now */
738
739	/*
740	 * On iSeries, we soft-disable interrupts here, then
741	 * hard-enable interrupts so that the hash_page code can spin on
742	 * the hash_table_lock without problems on a shared processor.
743	 */
744	DISABLE_INTS
745
746	/*
747	 * Currently, trace_hardirqs_off() will be called by DISABLE_INTS
748	 * and will clobber volatile registers when irq tracing is enabled
749	 * so we need to reload them. It may be possible to be smarter here
750	 * and move the irq tracing elsewhere but let's keep it simple for
751	 * now
752	 */
753#ifdef CONFIG_TRACE_IRQFLAGS
754	ld	r3,_DAR(r1)
755	ld	r4,_DSISR(r1)
756	ld	r5,_TRAP(r1)
757	ld	r12,_MSR(r1)
758	clrrdi	r5,r5,4
759#endif /* CONFIG_TRACE_IRQFLAGS */
760	/*
761	 * We need to set the _PAGE_USER bit if MSR_PR is set or if we are
762	 * accessing a userspace segment (even from the kernel). We assume
763	 * kernel addresses always have the high bit set.
764	 */
765	rlwinm	r4,r4,32-25+9,31-9,31-9	/* DSISR_STORE -> _PAGE_RW */
766	rotldi	r0,r3,15		/* Move high bit into MSR_PR posn */
767	orc	r0,r12,r0		/* MSR_PR | ~high_bit */
768	rlwimi	r4,r0,32-13,30,30	/* becomes _PAGE_USER access bit */
769	ori	r4,r4,1			/* add _PAGE_PRESENT */
770	rlwimi	r4,r5,22+2,31-2,31-2	/* Set _PAGE_EXEC if trap is 0x400 */
771
772	/*
773	 * r3 contains the faulting address
774	 * r4 contains the required access permissions
775	 * r5 contains the trap number
776	 *
777	 * at return r3 = 0 for success
778	 */
779	bl	.hash_page		/* build HPTE if possible */
780	cmpdi	r3,0			/* see if hash_page succeeded */
781
782BEGIN_FW_FTR_SECTION
783	/*
784	 * If we had interrupts soft-enabled at the point where the
785	 * DSI/ISI occurred, and an interrupt came in during hash_page,
786	 * handle it now.
787	 * We jump to ret_from_except_lite rather than fast_exception_return
788	 * because ret_from_except_lite will check for and handle pending
789	 * interrupts if necessary.
790	 */
791	beq	13f
792END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
793
794BEGIN_FW_FTR_SECTION
795	/*
796	 * Here we have interrupts hard-disabled, so it is sufficient
797	 * to restore paca->{soft,hard}_enable and get out.
798	 */
799	beq	fast_exc_return_irq	/* Return from exception on success */
800END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES)
801
802	/* For a hash failure, we don't bother re-enabling interrupts */
803	ble-	12f
804
805	/*
806	 * hash_page couldn't handle it, set soft interrupt enable back
807	 * to what it was before the trap.  Note that .raw_local_irq_restore
808	 * handles any interrupts pending at this point.
809	 */
810	ld	r3,SOFTE(r1)
811	TRACE_AND_RESTORE_IRQ_PARTIAL(r3, 11f)
812	bl	.raw_local_irq_restore
813	b	11f
814
815/* Here we have a page fault that hash_page can't handle. */
816handle_page_fault:
817	ENABLE_INTS
81811:	ld	r4,_DAR(r1)
819	ld	r5,_DSISR(r1)
820	addi	r3,r1,STACK_FRAME_OVERHEAD
821	bl	.do_page_fault
822	cmpdi	r3,0
823	beq+	13f
824	bl	.save_nvgprs
825	mr	r5,r3
826	addi	r3,r1,STACK_FRAME_OVERHEAD
827	lwz	r4,_DAR(r1)
828	bl	.bad_page_fault
829	b	.ret_from_except
830
83113:	b	.ret_from_except_lite
832
833/* We have a page fault that hash_page could handle but HV refused
834 * the PTE insertion
835 */
83612:	bl	.save_nvgprs
837	mr	r5,r3
838	addi	r3,r1,STACK_FRAME_OVERHEAD
839	ld	r4,_DAR(r1)
840	bl	.low_hash_fault
841	b	.ret_from_except
842
843/*
844 * We come here as a result of a DSI at a point where we don't want
845 * to call hash_page, such as when we are accessing memory (possibly
846 * user memory) inside a PMU interrupt that occurred while interrupts
847 * were soft-disabled.  We want to invoke the exception handler for
848 * the access, or panic if there isn't a handler.
849 */
85077:	bl	.save_nvgprs
851	mr	r4,r3
852	addi	r3,r1,STACK_FRAME_OVERHEAD
853	li	r5,SIGSEGV
854	bl	.bad_page_fault
855	b	.ret_from_except
856
857	/* here we have a segment miss */
858do_ste_alloc:
859	bl	.ste_allocate		/* try to insert stab entry */
860	cmpdi	r3,0
861	bne-	handle_page_fault
862	b	fast_exception_return
863
864/*
865 * r13 points to the PACA, r9 contains the saved CR,
866 * r11 and r12 contain the saved SRR0 and SRR1.
867 * r9 - r13 are saved in paca->exslb.
868 * We assume we aren't going to take any exceptions during this procedure.
869 * We assume (DAR >> 60) == 0xc.
870 */
871	.align	7
872_GLOBAL(do_stab_bolted)
873	stw	r9,PACA_EXSLB+EX_CCR(r13)	/* save CR in exc. frame */
874	std	r11,PACA_EXSLB+EX_SRR0(r13)	/* save SRR0 in exc. frame */
875
876	/* Hash to the primary group */
877	ld	r10,PACASTABVIRT(r13)
878	mfspr	r11,SPRN_DAR
879	srdi	r11,r11,28
880	rldimi	r10,r11,7,52	/* r10 = first ste of the group */
881
882	/* Calculate VSID */
883	/* This is a kernel address, so protovsid = ESID */
884	ASM_VSID_SCRAMBLE(r11, r9, 256M)
885	rldic	r9,r11,12,16	/* r9 = vsid << 12 */
886
887	/* Search the primary group for a free entry */
8881:	ld	r11,0(r10)	/* Test valid bit of the current ste	*/
889	andi.	r11,r11,0x80
890	beq	2f
891	addi	r10,r10,16
892	andi.	r11,r10,0x70
893	bne	1b
894
895	/* Stick for only searching the primary group for now.		*/
896	/* At least for now, we use a very simple random castout scheme */
897	/* Use the TB as a random number ;  OR in 1 to avoid entry 0	*/
898	mftb	r11
899	rldic	r11,r11,4,57	/* r11 = (r11 << 4) & 0x70 */
900	ori	r11,r11,0x10
901
902	/* r10 currently points to an ste one past the group of interest */
903	/* make it point to the randomly selected entry			*/
904	subi	r10,r10,128
905	or 	r10,r10,r11	/* r10 is the entry to invalidate	*/
906
907	isync			/* mark the entry invalid		*/
908	ld	r11,0(r10)
909	rldicl	r11,r11,56,1	/* clear the valid bit */
910	rotldi	r11,r11,8
911	std	r11,0(r10)
912	sync
913
914	clrrdi	r11,r11,28	/* Get the esid part of the ste		*/
915	slbie	r11
916
9172:	std	r9,8(r10)	/* Store the vsid part of the ste	*/
918	eieio
919
920	mfspr	r11,SPRN_DAR		/* Get the new esid			*/
921	clrrdi	r11,r11,28	/* Permits a full 32b of ESID		*/
922	ori	r11,r11,0x90	/* Turn on valid and kp			*/
923	std	r11,0(r10)	/* Put new entry back into the stab	*/
924
925	sync
926
927	/* All done -- return from exception. */
928	lwz	r9,PACA_EXSLB+EX_CCR(r13)	/* get saved CR */
929	ld	r11,PACA_EXSLB+EX_SRR0(r13)	/* get saved SRR0 */
930
931	andi.	r10,r12,MSR_RI
932	beq-	unrecov_slb
933
934	mtcrf	0x80,r9			/* restore CR */
935
936	mfmsr	r10
937	clrrdi	r10,r10,2
938	mtmsrd	r10,1
939
940	mtspr	SPRN_SRR0,r11
941	mtspr	SPRN_SRR1,r12
942	ld	r9,PACA_EXSLB+EX_R9(r13)
943	ld	r10,PACA_EXSLB+EX_R10(r13)
944	ld	r11,PACA_EXSLB+EX_R11(r13)
945	ld	r12,PACA_EXSLB+EX_R12(r13)
946	ld	r13,PACA_EXSLB+EX_R13(r13)
947	rfid
948	b	.	/* prevent speculative execution */
949
950/*
951 * Space for CPU0's segment table.
952 *
953 * On iSeries, the hypervisor must fill in at least one entry before
954 * we get control (with relocate on).  The address is given to the hv
955 * as a page number (see xLparMap below), so this must be at a
956 * fixed address (the linker can't compute (u64)&initial_stab >>
957 * PAGE_SHIFT).
958 */
959	. = STAB0_OFFSET	/* 0x6000 */
960	.globl initial_stab
961initial_stab:
962	.space	4096
963
964#ifdef CONFIG_PPC_PSERIES
965/*
966 * Data area reserved for FWNMI option.
967 * This address (0x7000) is fixed by the RPA.
968 */
969	.= 0x7000
970	.globl fwnmi_data_area
971fwnmi_data_area:
972#endif /* CONFIG_PPC_PSERIES */
973
974	/* iSeries does not use the FWNMI stuff, so it is safe to put
975	 * this here, even if we later allow kernels that will boot on
976	 * both pSeries and iSeries */
977#ifdef CONFIG_PPC_ISERIES
978        . = LPARMAP_PHYS
979	.globl xLparMap
980xLparMap:
981	.quad	HvEsidsToMap		/* xNumberEsids */
982	.quad	HvRangesToMap		/* xNumberRanges */
983	.quad	STAB0_PAGE		/* xSegmentTableOffs */
984	.zero	40			/* xRsvd */
985	/* xEsids (HvEsidsToMap entries of 2 quads) */
986	.quad	PAGE_OFFSET_ESID	/* xKernelEsid */
987	.quad	PAGE_OFFSET_VSID	/* xKernelVsid */
988	.quad	VMALLOC_START_ESID	/* xKernelEsid */
989	.quad	VMALLOC_START_VSID	/* xKernelVsid */
990	/* xRanges (HvRangesToMap entries of 3 quads) */
991	.quad	HvPagesToMap		/* xPages */
992	.quad	0			/* xOffset */
993	.quad	PAGE_OFFSET_VSID << (SID_SHIFT - HW_PAGE_SHIFT)	/* xVPN */
994
995#endif /* CONFIG_PPC_ISERIES */
996
997#ifdef CONFIG_PPC_PSERIES
998        . = 0x8000
999#endif /* CONFIG_PPC_PSERIES */
1000