xref: /openbmc/linux/arch/powerpc/kernel/exceptions-64e.S (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
1/*
2 *  Boot code and exception vectors for Book3E processors
3 *
4 *  Copyright (C) 2007 Ben. Herrenschmidt (benh@kernel.crashing.org), IBM Corp.
5 *
6 *  This program is free software; you can redistribute it and/or
7 *  modify it under the terms of the GNU General Public License
8 *  as published by the Free Software Foundation; either version
9 *  2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/threads.h>
13#include <asm/reg.h>
14#include <asm/page.h>
15#include <asm/ppc_asm.h>
16#include <asm/asm-offsets.h>
17#include <asm/cputable.h>
18#include <asm/setup.h>
19#include <asm/thread_info.h>
20#include <asm/exception-64e.h>
21#include <asm/bug.h>
22#include <asm/irqflags.h>
23#include <asm/ptrace.h>
24#include <asm/ppc-opcode.h>
25#include <asm/mmu.h>
26
27/* XXX This will ultimately add space for a special exception save
28 *     structure used to save things like SRR0/SRR1, SPRGs, MAS, etc...
29 *     when taking special interrupts. For now we don't support that,
30 *     special interrupts from within a non-standard level will probably
31 *     blow you up
32 */
33#define	SPECIAL_EXC_FRAME_SIZE	INT_FRAME_SIZE
34
35/* Exception prolog code for all exceptions */
36#define EXCEPTION_PROLOG(n, type, addition)				    \
37	mtspr	SPRN_SPRG_##type##_SCRATCH,r13;	/* get spare registers */   \
38	mfspr	r13,SPRN_SPRG_PACA;	/* get PACA */			    \
39	std	r10,PACA_EX##type+EX_R10(r13);				    \
40	std	r11,PACA_EX##type+EX_R11(r13);				    \
41	mfcr	r10;			/* save CR */			    \
42	addition;			/* additional code for that exc. */ \
43	std	r1,PACA_EX##type+EX_R1(r13); /* save old r1 in the PACA */  \
44	stw	r10,PACA_EX##type+EX_CR(r13); /* save old CR in the PACA */ \
45	mfspr	r11,SPRN_##type##_SRR1;/* what are we coming from */	    \
46	type##_SET_KSTACK;		/* get special stack if necessary */\
47	andi.	r10,r11,MSR_PR;		/* save stack pointer */	    \
48	beq	1f;			/* branch around if supervisor */   \
49	ld	r1,PACAKSAVE(r13);	/* get kernel stack coming from usr */\
501:	cmpdi	cr1,r1,0;		/* check if SP makes sense */	    \
51	bge-	cr1,exc_##n##_bad_stack;/* bad stack (TODO: out of line) */ \
52	mfspr	r10,SPRN_##type##_SRR0;	/* read SRR0 before touching stack */
53
54/* Exception type-specific macros */
55#define	GEN_SET_KSTACK							    \
56	subi	r1,r1,INT_FRAME_SIZE;	/* alloc frame on kernel stack */
57#define SPRN_GEN_SRR0	SPRN_SRR0
58#define SPRN_GEN_SRR1	SPRN_SRR1
59
60#define CRIT_SET_KSTACK						            \
61	ld	r1,PACA_CRIT_STACK(r13);				    \
62	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
63#define SPRN_CRIT_SRR0	SPRN_CSRR0
64#define SPRN_CRIT_SRR1	SPRN_CSRR1
65
66#define DBG_SET_KSTACK						            \
67	ld	r1,PACA_DBG_STACK(r13);					    \
68	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
69#define SPRN_DBG_SRR0	SPRN_DSRR0
70#define SPRN_DBG_SRR1	SPRN_DSRR1
71
72#define MC_SET_KSTACK						            \
73	ld	r1,PACA_MC_STACK(r13);					    \
74	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
75#define SPRN_MC_SRR0	SPRN_MCSRR0
76#define SPRN_MC_SRR1	SPRN_MCSRR1
77
78#define NORMAL_EXCEPTION_PROLOG(n, addition)				    \
79	EXCEPTION_PROLOG(n, GEN, addition##_GEN)
80
81#define CRIT_EXCEPTION_PROLOG(n, addition)				    \
82	EXCEPTION_PROLOG(n, CRIT, addition##_CRIT)
83
84#define DBG_EXCEPTION_PROLOG(n, addition)				    \
85	EXCEPTION_PROLOG(n, DBG, addition##_DBG)
86
87#define MC_EXCEPTION_PROLOG(n, addition)				    \
88	EXCEPTION_PROLOG(n, MC, addition##_MC)
89
90
91/* Variants of the "addition" argument for the prolog
92 */
93#define PROLOG_ADDITION_NONE_GEN
94#define PROLOG_ADDITION_NONE_CRIT
95#define PROLOG_ADDITION_NONE_DBG
96#define PROLOG_ADDITION_NONE_MC
97
98#define PROLOG_ADDITION_MASKABLE_GEN					    \
99	lbz	r11,PACASOFTIRQEN(r13); /* are irqs soft-disabled ? */	    \
100	cmpwi	cr0,r11,0;		/* yes -> go out of line */	    \
101	beq	masked_interrupt_book3e;
102
103#define PROLOG_ADDITION_2REGS_GEN					    \
104	std	r14,PACA_EXGEN+EX_R14(r13);				    \
105	std	r15,PACA_EXGEN+EX_R15(r13)
106
107#define PROLOG_ADDITION_1REG_GEN					    \
108	std	r14,PACA_EXGEN+EX_R14(r13);
109
110#define PROLOG_ADDITION_2REGS_CRIT					    \
111	std	r14,PACA_EXCRIT+EX_R14(r13);				    \
112	std	r15,PACA_EXCRIT+EX_R15(r13)
113
114#define PROLOG_ADDITION_2REGS_DBG					    \
115	std	r14,PACA_EXDBG+EX_R14(r13);				    \
116	std	r15,PACA_EXDBG+EX_R15(r13)
117
118#define PROLOG_ADDITION_2REGS_MC					    \
119	std	r14,PACA_EXMC+EX_R14(r13);				    \
120	std	r15,PACA_EXMC+EX_R15(r13)
121
122/* Core exception code for all exceptions except TLB misses.
123 * XXX: Needs to make SPRN_SPRG_GEN depend on exception type
124 */
125#define EXCEPTION_COMMON(n, excf, ints)					    \
126	std	r0,GPR0(r1);		/* save r0 in stackframe */	    \
127	std	r2,GPR2(r1);		/* save r2 in stackframe */	    \
128	SAVE_4GPRS(3, r1);		/* save r3 - r6 in stackframe */    \
129	SAVE_2GPRS(7, r1);		/* save r7, r8 in stackframe */	    \
130	std	r9,GPR9(r1);		/* save r9 in stackframe */	    \
131	std	r10,_NIP(r1);		/* save SRR0 to stackframe */	    \
132	std	r11,_MSR(r1);		/* save SRR1 to stackframe */	    \
133	ACCOUNT_CPU_USER_ENTRY(r10,r11);/* accounting (uses cr0+eq) */	    \
134	ld	r3,excf+EX_R10(r13);	/* get back r10 */		    \
135	ld	r4,excf+EX_R11(r13);	/* get back r11 */		    \
136	mfspr	r5,SPRN_SPRG_GEN_SCRATCH;/* get back r13 */		    \
137	std	r12,GPR12(r1);		/* save r12 in stackframe */	    \
138	ld	r2,PACATOC(r13);	/* get kernel TOC into r2 */	    \
139	mflr	r6;			/* save LR in stackframe */	    \
140	mfctr	r7;			/* save CTR in stackframe */	    \
141	mfspr	r8,SPRN_XER;		/* save XER in stackframe */	    \
142	ld	r9,excf+EX_R1(r13);	/* load orig r1 back from PACA */   \
143	lwz	r10,excf+EX_CR(r13);	/* load orig CR back from PACA	*/  \
144	lbz	r11,PACASOFTIRQEN(r13);	/* get current IRQ softe */	    \
145	ld	r12,exception_marker@toc(r2);				    \
146	li	r0,0;							    \
147	std	r3,GPR10(r1);		/* save r10 to stackframe */	    \
148	std	r4,GPR11(r1);		/* save r11 to stackframe */	    \
149	std	r5,GPR13(r1);		/* save it to stackframe */	    \
150	std	r6,_LINK(r1);						    \
151	std	r7,_CTR(r1);						    \
152	std	r8,_XER(r1);						    \
153	li	r3,(n)+1;		/* indicate partial regs in trap */ \
154	std	r9,0(r1);		/* store stack frame back link */   \
155	std	r10,_CCR(r1);		/* store orig CR in stackframe */   \
156	std	r9,GPR1(r1);		/* store stack frame back link */   \
157	std	r11,SOFTE(r1);		/* and save it to stackframe */     \
158	std	r12,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame */	    \
159	std	r3,_TRAP(r1);		/* set trap number		*/  \
160	std	r0,RESULT(r1);		/* clear regs->result */	    \
161	ints;
162
163/* Variants for the "ints" argument */
164#define INTS_KEEP
165#define INTS_DISABLE_SOFT						    \
166	stb	r0,PACASOFTIRQEN(r13);	/* mark interrupts soft-disabled */ \
167	TRACE_DISABLE_INTS;
168#define INTS_DISABLE_HARD						    \
169	stb	r0,PACAHARDIRQEN(r13); /* and hard disabled */
170#define INTS_DISABLE_ALL						    \
171	INTS_DISABLE_SOFT						    \
172	INTS_DISABLE_HARD
173
174/* This is called by exceptions that used INTS_KEEP (that is did not clear
175 * neither soft nor hard IRQ indicators in the PACA. This will restore MSR:EE
176 * to it's previous value
177 *
178 * XXX In the long run, we may want to open-code it in order to separate the
179 *     load from the wrtee, thus limiting the latency caused by the dependency
180 *     but at this point, I'll favor code clarity until we have a near to final
181 *     implementation
182 */
183#define INTS_RESTORE_HARD						    \
184	ld	r11,_MSR(r1);						    \
185	wrtee	r11;
186
187/* XXX FIXME: Restore r14/r15 when necessary */
188#define BAD_STACK_TRAMPOLINE(n)						    \
189exc_##n##_bad_stack:							    \
190	li	r1,(n);			/* get exception number */	    \
191	sth	r1,PACA_TRAP_SAVE(r13);	/* store trap */		    \
192	b	bad_stack_book3e;	/* bad stack error */
193
194/* WARNING: If you change the layout of this stub, make sure you chcek
195	*   the debug exception handler which handles single stepping
196	*   into exceptions from userspace, and the MM code in
197	*   arch/powerpc/mm/tlb_nohash.c which patches the branch here
198	*   and would need to be updated if that branch is moved
199	*/
200#define	EXCEPTION_STUB(loc, label)					\
201	. = interrupt_base_book3e + loc;				\
202	nop;	/* To make debug interrupts happy */			\
203	b	exc_##label##_book3e;
204
205#define ACK_NONE(r)
206#define ACK_DEC(r)							\
207	lis	r,TSR_DIS@h;						\
208	mtspr	SPRN_TSR,r
209#define ACK_FIT(r)							\
210	lis	r,TSR_FIS@h;						\
211	mtspr	SPRN_TSR,r
212
213/* Used by asynchronous interrupt that may happen in the idle loop.
214 *
215 * This check if the thread was in the idle loop, and if yes, returns
216 * to the caller rather than the PC. This is to avoid a race if
217 * interrupts happen before the wait instruction.
218 */
219#define CHECK_NAPPING()							\
220	clrrdi	r11,r1,THREAD_SHIFT;					\
221	ld	r10,TI_LOCAL_FLAGS(r11);				\
222	andi.	r9,r10,_TLF_NAPPING;					\
223	beq+	1f;							\
224	ld	r8,_LINK(r1);						\
225	rlwinm	r7,r10,0,~_TLF_NAPPING;					\
226	std	r8,_NIP(r1);						\
227	std	r7,TI_LOCAL_FLAGS(r11);					\
2281:
229
230
231#define MASKABLE_EXCEPTION(trapnum, label, hdlr, ack)			\
232	START_EXCEPTION(label);						\
233	NORMAL_EXCEPTION_PROLOG(trapnum, PROLOG_ADDITION_MASKABLE)	\
234	EXCEPTION_COMMON(trapnum, PACA_EXGEN, INTS_DISABLE_ALL)		\
235	ack(r8);							\
236	CHECK_NAPPING();						\
237	addi	r3,r1,STACK_FRAME_OVERHEAD;				\
238	bl	hdlr;							\
239	b	.ret_from_except_lite;
240
241/* This value is used to mark exception frames on the stack. */
242	.section	".toc","aw"
243exception_marker:
244	.tc	ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER
245
246
247/*
248 * And here we have the exception vectors !
249 */
250
251	.text
252	.balign	0x1000
253	.globl interrupt_base_book3e
254interrupt_base_book3e:					/* fake trap */
255	/* Note: If real debug exceptions are supported by the HW, the vector
256	 * below will have to be patched up to point to an appropriate handler
257	 */
258	EXCEPTION_STUB(0x000, machine_check)		/* 0x0200 */
259	EXCEPTION_STUB(0x020, critical_input)		/* 0x0580 */
260	EXCEPTION_STUB(0x040, debug_crit)		/* 0x0d00 */
261	EXCEPTION_STUB(0x060, data_storage)		/* 0x0300 */
262	EXCEPTION_STUB(0x080, instruction_storage)	/* 0x0400 */
263	EXCEPTION_STUB(0x0a0, external_input)		/* 0x0500 */
264	EXCEPTION_STUB(0x0c0, alignment)		/* 0x0600 */
265	EXCEPTION_STUB(0x0e0, program)			/* 0x0700 */
266	EXCEPTION_STUB(0x100, fp_unavailable)		/* 0x0800 */
267	EXCEPTION_STUB(0x120, system_call)		/* 0x0c00 */
268	EXCEPTION_STUB(0x140, ap_unavailable)		/* 0x0f20 */
269	EXCEPTION_STUB(0x160, decrementer)		/* 0x0900 */
270	EXCEPTION_STUB(0x180, fixed_interval)		/* 0x0980 */
271	EXCEPTION_STUB(0x1a0, watchdog)			/* 0x09f0 */
272	EXCEPTION_STUB(0x1c0, data_tlb_miss)
273	EXCEPTION_STUB(0x1e0, instruction_tlb_miss)
274	EXCEPTION_STUB(0x280, doorbell)
275	EXCEPTION_STUB(0x2a0, doorbell_crit)
276
277	.globl interrupt_end_book3e
278interrupt_end_book3e:
279
280/* Critical Input Interrupt */
281	START_EXCEPTION(critical_input);
282	CRIT_EXCEPTION_PROLOG(0x100, PROLOG_ADDITION_NONE)
283//	EXCEPTION_COMMON(0x100, PACA_EXCRIT, INTS_DISABLE_ALL)
284//	bl	special_reg_save_crit
285//	CHECK_NAPPING();
286//	addi	r3,r1,STACK_FRAME_OVERHEAD
287//	bl	.critical_exception
288//	b	ret_from_crit_except
289	b	.
290
291/* Machine Check Interrupt */
292	START_EXCEPTION(machine_check);
293	CRIT_EXCEPTION_PROLOG(0x200, PROLOG_ADDITION_NONE)
294//	EXCEPTION_COMMON(0x200, PACA_EXMC, INTS_DISABLE_ALL)
295//	bl	special_reg_save_mc
296//	addi	r3,r1,STACK_FRAME_OVERHEAD
297//	CHECK_NAPPING();
298//	bl	.machine_check_exception
299//	b	ret_from_mc_except
300	b	.
301
302/* Data Storage Interrupt */
303	START_EXCEPTION(data_storage)
304	NORMAL_EXCEPTION_PROLOG(0x300, PROLOG_ADDITION_2REGS)
305	mfspr	r14,SPRN_DEAR
306	mfspr	r15,SPRN_ESR
307	EXCEPTION_COMMON(0x300, PACA_EXGEN, INTS_KEEP)
308	b	storage_fault_common
309
310/* Instruction Storage Interrupt */
311	START_EXCEPTION(instruction_storage);
312	NORMAL_EXCEPTION_PROLOG(0x400, PROLOG_ADDITION_2REGS)
313	li	r15,0
314	mr	r14,r10
315	EXCEPTION_COMMON(0x400, PACA_EXGEN, INTS_KEEP)
316	b	storage_fault_common
317
318/* External Input Interrupt */
319	MASKABLE_EXCEPTION(0x500, external_input, .do_IRQ, ACK_NONE)
320
321/* Alignment */
322	START_EXCEPTION(alignment);
323	NORMAL_EXCEPTION_PROLOG(0x600, PROLOG_ADDITION_2REGS)
324	mfspr	r14,SPRN_DEAR
325	mfspr	r15,SPRN_ESR
326	EXCEPTION_COMMON(0x600, PACA_EXGEN, INTS_KEEP)
327	b	alignment_more	/* no room, go out of line */
328
329/* Program Interrupt */
330	START_EXCEPTION(program);
331	NORMAL_EXCEPTION_PROLOG(0x700, PROLOG_ADDITION_1REG)
332	mfspr	r14,SPRN_ESR
333	EXCEPTION_COMMON(0x700, PACA_EXGEN, INTS_DISABLE_SOFT)
334	std	r14,_DSISR(r1)
335	addi	r3,r1,STACK_FRAME_OVERHEAD
336	ld	r14,PACA_EXGEN+EX_R14(r13)
337	bl	.save_nvgprs
338	INTS_RESTORE_HARD
339	bl	.program_check_exception
340	b	.ret_from_except
341
342/* Floating Point Unavailable Interrupt */
343	START_EXCEPTION(fp_unavailable);
344	NORMAL_EXCEPTION_PROLOG(0x800, PROLOG_ADDITION_NONE)
345	/* we can probably do a shorter exception entry for that one... */
346	EXCEPTION_COMMON(0x800, PACA_EXGEN, INTS_KEEP)
347	bne	1f			/* if from user, just load it up */
348	bl	.save_nvgprs
349	addi	r3,r1,STACK_FRAME_OVERHEAD
350	INTS_RESTORE_HARD
351	bl	.kernel_fp_unavailable_exception
352	BUG_OPCODE
3531:	ld	r12,_MSR(r1)
354	bl	.load_up_fpu
355	b	fast_exception_return
356
357/* Decrementer Interrupt */
358	MASKABLE_EXCEPTION(0x900, decrementer, .timer_interrupt, ACK_DEC)
359
360/* Fixed Interval Timer Interrupt */
361	MASKABLE_EXCEPTION(0x980, fixed_interval, .unknown_exception, ACK_FIT)
362
363/* Watchdog Timer Interrupt */
364	START_EXCEPTION(watchdog);
365	CRIT_EXCEPTION_PROLOG(0x9f0, PROLOG_ADDITION_NONE)
366//	EXCEPTION_COMMON(0x9f0, PACA_EXCRIT, INTS_DISABLE_ALL)
367//	bl	special_reg_save_crit
368//	CHECK_NAPPING();
369//	addi	r3,r1,STACK_FRAME_OVERHEAD
370//	bl	.unknown_exception
371//	b	ret_from_crit_except
372	b	.
373
374/* System Call Interrupt */
375	START_EXCEPTION(system_call)
376	mr	r9,r13			/* keep a copy of userland r13 */
377	mfspr	r11,SPRN_SRR0		/* get return address */
378	mfspr	r12,SPRN_SRR1		/* get previous MSR */
379	mfspr	r13,SPRN_SPRG_PACA	/* get our PACA */
380	b	system_call_common
381
382/* Auxillary Processor Unavailable Interrupt */
383	START_EXCEPTION(ap_unavailable);
384	NORMAL_EXCEPTION_PROLOG(0xf20, PROLOG_ADDITION_NONE)
385	EXCEPTION_COMMON(0xf20, PACA_EXGEN, INTS_KEEP)
386	addi	r3,r1,STACK_FRAME_OVERHEAD
387	bl	.save_nvgprs
388	INTS_RESTORE_HARD
389	bl	.unknown_exception
390	b	.ret_from_except
391
392/* Debug exception as a critical interrupt*/
393	START_EXCEPTION(debug_crit);
394	CRIT_EXCEPTION_PROLOG(0xd00, PROLOG_ADDITION_2REGS)
395
396	/*
397	 * If there is a single step or branch-taken exception in an
398	 * exception entry sequence, it was probably meant to apply to
399	 * the code where the exception occurred (since exception entry
400	 * doesn't turn off DE automatically).  We simulate the effect
401	 * of turning off DE on entry to an exception handler by turning
402	 * off DE in the CSRR1 value and clearing the debug status.
403	 */
404
405	mfspr	r14,SPRN_DBSR		/* check single-step/branch taken */
406	andis.	r15,r14,DBSR_IC@h
407	beq+	1f
408
409	LOAD_REG_IMMEDIATE(r14,interrupt_base_book3e)
410	LOAD_REG_IMMEDIATE(r15,interrupt_end_book3e)
411	cmpld	cr0,r10,r14
412	cmpld	cr1,r10,r15
413	blt+	cr0,1f
414	bge+	cr1,1f
415
416	/* here it looks like we got an inappropriate debug exception. */
417	lis	r14,DBSR_IC@h		/* clear the IC event */
418	rlwinm	r11,r11,0,~MSR_DE	/* clear DE in the CSRR1 value */
419	mtspr	SPRN_DBSR,r14
420	mtspr	SPRN_CSRR1,r11
421	lwz	r10,PACA_EXCRIT+EX_CR(r13)	/* restore registers */
422	ld	r1,PACA_EXCRIT+EX_R1(r13)
423	ld	r14,PACA_EXCRIT+EX_R14(r13)
424	ld	r15,PACA_EXCRIT+EX_R15(r13)
425	mtcr	r10
426	ld	r10,PACA_EXCRIT+EX_R10(r13)	/* restore registers */
427	ld	r11,PACA_EXCRIT+EX_R11(r13)
428	mfspr	r13,SPRN_SPRG_CRIT_SCRATCH
429	rfci
430
431	/* Normal debug exception */
432	/* XXX We only handle coming from userspace for now since we can't
433	 *     quite save properly an interrupted kernel state yet
434	 */
4351:	andi.	r14,r11,MSR_PR;		/* check for userspace again */
436	beq	kernel_dbg_exc;		/* if from kernel mode */
437
438	/* Now we mash up things to make it look like we are coming on a
439	 * normal exception
440	 */
441	mfspr	r15,SPRN_SPRG_CRIT_SCRATCH
442	mtspr	SPRN_SPRG_GEN_SCRATCH,r15
443	mfspr	r14,SPRN_DBSR
444	EXCEPTION_COMMON(0xd00, PACA_EXCRIT, INTS_DISABLE_ALL)
445	std	r14,_DSISR(r1)
446	addi	r3,r1,STACK_FRAME_OVERHEAD
447	mr	r4,r14
448	ld	r14,PACA_EXCRIT+EX_R14(r13)
449	ld	r15,PACA_EXCRIT+EX_R15(r13)
450	bl	.save_nvgprs
451	bl	.DebugException
452	b	.ret_from_except
453
454kernel_dbg_exc:
455	b	.	/* NYI */
456
457/* Doorbell interrupt */
458	MASKABLE_EXCEPTION(0x2070, doorbell, .doorbell_exception, ACK_NONE)
459
460/* Doorbell critical Interrupt */
461	START_EXCEPTION(doorbell_crit);
462	CRIT_EXCEPTION_PROLOG(0x2080, PROLOG_ADDITION_NONE)
463//	EXCEPTION_COMMON(0x2080, PACA_EXCRIT, INTS_DISABLE_ALL)
464//	bl	special_reg_save_crit
465//	CHECK_NAPPING();
466//	addi	r3,r1,STACK_FRAME_OVERHEAD
467//	bl	.doorbell_critical_exception
468//	b	ret_from_crit_except
469	b	.
470
471
472/*
473 * An interrupt came in while soft-disabled; clear EE in SRR1,
474 * clear paca->hard_enabled and return.
475 */
476masked_interrupt_book3e:
477	mtcr	r10
478	stb	r11,PACAHARDIRQEN(r13)
479	mfspr	r10,SPRN_SRR1
480	rldicl	r11,r10,48,1		/* clear MSR_EE */
481	rotldi	r10,r11,16
482	mtspr	SPRN_SRR1,r10
483	ld	r10,PACA_EXGEN+EX_R10(r13);	/* restore registers */
484	ld	r11,PACA_EXGEN+EX_R11(r13);
485	mfspr	r13,SPRN_SPRG_GEN_SCRATCH;
486	rfi
487	b	.
488
489/*
490 * This is called from 0x300 and 0x400 handlers after the prologs with
491 * r14 and r15 containing the fault address and error code, with the
492 * original values stashed away in the PACA
493 */
494storage_fault_common:
495	std	r14,_DAR(r1)
496	std	r15,_DSISR(r1)
497	addi	r3,r1,STACK_FRAME_OVERHEAD
498	mr	r4,r14
499	mr	r5,r15
500	ld	r14,PACA_EXGEN+EX_R14(r13)
501	ld	r15,PACA_EXGEN+EX_R15(r13)
502	INTS_RESTORE_HARD
503	bl	.do_page_fault
504	cmpdi	r3,0
505	bne-	1f
506	b	.ret_from_except_lite
5071:	bl	.save_nvgprs
508	mr	r5,r3
509	addi	r3,r1,STACK_FRAME_OVERHEAD
510	ld	r4,_DAR(r1)
511	bl	.bad_page_fault
512	b	.ret_from_except
513
514/*
515 * Alignment exception doesn't fit entirely in the 0x100 bytes so it
516 * continues here.
517 */
518alignment_more:
519	std	r14,_DAR(r1)
520	std	r15,_DSISR(r1)
521	addi	r3,r1,STACK_FRAME_OVERHEAD
522	ld	r14,PACA_EXGEN+EX_R14(r13)
523	ld	r15,PACA_EXGEN+EX_R15(r13)
524	bl	.save_nvgprs
525	INTS_RESTORE_HARD
526	bl	.alignment_exception
527	b	.ret_from_except
528
529/*
530 * We branch here from entry_64.S for the last stage of the exception
531 * return code path. MSR:EE is expected to be off at that point
532 */
533_GLOBAL(exception_return_book3e)
534	b	1f
535
536/* This is the return from load_up_fpu fast path which could do with
537 * less GPR restores in fact, but for now we have a single return path
538 */
539	.globl fast_exception_return
540fast_exception_return:
541	wrteei	0
5421:	mr	r0,r13
543	ld	r10,_MSR(r1)
544	REST_4GPRS(2, r1)
545	andi.	r6,r10,MSR_PR
546	REST_2GPRS(6, r1)
547	beq	1f
548	ACCOUNT_CPU_USER_EXIT(r10, r11)
549	ld	r0,GPR13(r1)
550
5511:	stdcx.	r0,0,r1		/* to clear the reservation */
552
553	ld	r8,_CCR(r1)
554	ld	r9,_LINK(r1)
555	ld	r10,_CTR(r1)
556	ld	r11,_XER(r1)
557	mtcr	r8
558	mtlr	r9
559	mtctr	r10
560	mtxer	r11
561	REST_2GPRS(8, r1)
562	ld	r10,GPR10(r1)
563	ld	r11,GPR11(r1)
564	ld	r12,GPR12(r1)
565	mtspr	SPRN_SPRG_GEN_SCRATCH,r0
566
567	std	r10,PACA_EXGEN+EX_R10(r13);
568	std	r11,PACA_EXGEN+EX_R11(r13);
569	ld	r10,_NIP(r1)
570	ld	r11,_MSR(r1)
571	ld	r0,GPR0(r1)
572	ld	r1,GPR1(r1)
573	mtspr	SPRN_SRR0,r10
574	mtspr	SPRN_SRR1,r11
575	ld	r10,PACA_EXGEN+EX_R10(r13)
576	ld	r11,PACA_EXGEN+EX_R11(r13)
577	mfspr	r13,SPRN_SPRG_GEN_SCRATCH
578	rfi
579
580/*
581 * Trampolines used when spotting a bad kernel stack pointer in
582 * the exception entry code.
583 *
584 * TODO: move some bits like SRR0 read to trampoline, pass PACA
585 * index around, etc... to handle crit & mcheck
586 */
587BAD_STACK_TRAMPOLINE(0x000)
588BAD_STACK_TRAMPOLINE(0x100)
589BAD_STACK_TRAMPOLINE(0x200)
590BAD_STACK_TRAMPOLINE(0x300)
591BAD_STACK_TRAMPOLINE(0x400)
592BAD_STACK_TRAMPOLINE(0x500)
593BAD_STACK_TRAMPOLINE(0x600)
594BAD_STACK_TRAMPOLINE(0x700)
595BAD_STACK_TRAMPOLINE(0x800)
596BAD_STACK_TRAMPOLINE(0x900)
597BAD_STACK_TRAMPOLINE(0x980)
598BAD_STACK_TRAMPOLINE(0x9f0)
599BAD_STACK_TRAMPOLINE(0xa00)
600BAD_STACK_TRAMPOLINE(0xb00)
601BAD_STACK_TRAMPOLINE(0xc00)
602BAD_STACK_TRAMPOLINE(0xd00)
603BAD_STACK_TRAMPOLINE(0xe00)
604BAD_STACK_TRAMPOLINE(0xf00)
605BAD_STACK_TRAMPOLINE(0xf20)
606BAD_STACK_TRAMPOLINE(0x2070)
607BAD_STACK_TRAMPOLINE(0x2080)
608
609	.globl	bad_stack_book3e
610bad_stack_book3e:
611	/* XXX: Needs to make SPRN_SPRG_GEN depend on exception type */
612	mfspr	r10,SPRN_SRR0;		  /* read SRR0 before touching stack */
613	ld	r1,PACAEMERGSP(r13)
614	subi	r1,r1,64+INT_FRAME_SIZE
615	std	r10,_NIP(r1)
616	std	r11,_MSR(r1)
617	ld	r10,PACA_EXGEN+EX_R1(r13) /* FIXME for crit & mcheck */
618	lwz	r11,PACA_EXGEN+EX_CR(r13) /* FIXME for crit & mcheck */
619	std	r10,GPR1(r1)
620	std	r11,_CCR(r1)
621	mfspr	r10,SPRN_DEAR
622	mfspr	r11,SPRN_ESR
623	std	r10,_DAR(r1)
624	std	r11,_DSISR(r1)
625	std	r0,GPR0(r1);		/* save r0 in stackframe */	    \
626	std	r2,GPR2(r1);		/* save r2 in stackframe */	    \
627	SAVE_4GPRS(3, r1);		/* save r3 - r6 in stackframe */    \
628	SAVE_2GPRS(7, r1);		/* save r7, r8 in stackframe */	    \
629	std	r9,GPR9(r1);		/* save r9 in stackframe */	    \
630	ld	r3,PACA_EXGEN+EX_R10(r13);/* get back r10 */		    \
631	ld	r4,PACA_EXGEN+EX_R11(r13);/* get back r11 */		    \
632	mfspr	r5,SPRN_SPRG_GEN_SCRATCH;/* get back r13 XXX can be wrong */ \
633	std	r3,GPR10(r1);		/* save r10 to stackframe */	    \
634	std	r4,GPR11(r1);		/* save r11 to stackframe */	    \
635	std	r12,GPR12(r1);		/* save r12 in stackframe */	    \
636	std	r5,GPR13(r1);		/* save it to stackframe */	    \
637	mflr	r10
638	mfctr	r11
639	mfxer	r12
640	std	r10,_LINK(r1)
641	std	r11,_CTR(r1)
642	std	r12,_XER(r1)
643	SAVE_10GPRS(14,r1)
644	SAVE_8GPRS(24,r1)
645	lhz	r12,PACA_TRAP_SAVE(r13)
646	std	r12,_TRAP(r1)
647	addi	r11,r1,INT_FRAME_SIZE
648	std	r11,0(r1)
649	li	r12,0
650	std	r12,0(r11)
651	ld	r2,PACATOC(r13)
6521:	addi	r3,r1,STACK_FRAME_OVERHEAD
653	bl	.kernel_bad_stack
654	b	1b
655
656/*
657 * Setup the initial TLB for a core. This current implementation
658 * assume that whatever we are running off will not conflict with
659 * the new mapping at PAGE_OFFSET.
660 */
661_GLOBAL(initial_tlb_book3e)
662
663	/* Look for the first TLB with IPROT set */
664	mfspr	r4,SPRN_TLB0CFG
665	andi.	r3,r4,TLBnCFG_IPROT
666	lis	r3,MAS0_TLBSEL(0)@h
667	bne	found_iprot
668
669	mfspr	r4,SPRN_TLB1CFG
670	andi.	r3,r4,TLBnCFG_IPROT
671	lis	r3,MAS0_TLBSEL(1)@h
672	bne	found_iprot
673
674	mfspr	r4,SPRN_TLB2CFG
675	andi.	r3,r4,TLBnCFG_IPROT
676	lis	r3,MAS0_TLBSEL(2)@h
677	bne	found_iprot
678
679	lis	r3,MAS0_TLBSEL(3)@h
680	mfspr	r4,SPRN_TLB3CFG
681	/* fall through */
682
683found_iprot:
684	andi.	r5,r4,TLBnCFG_HES
685	bne	have_hes
686
687	mflr	r8				/* save LR */
688/* 1. Find the index of the entry we're executing in
689 *
690 * r3 = MAS0_TLBSEL (for the iprot array)
691 * r4 = SPRN_TLBnCFG
692 */
693	bl	invstr				/* Find our address */
694invstr:	mflr	r6				/* Make it accessible */
695	mfmsr	r7
696	rlwinm	r5,r7,27,31,31			/* extract MSR[IS] */
697	mfspr	r7,SPRN_PID
698	slwi	r7,r7,16
699	or	r7,r7,r5
700	mtspr	SPRN_MAS6,r7
701	tlbsx	0,r6				/* search MSR[IS], SPID=PID */
702
703	mfspr	r3,SPRN_MAS0
704	rlwinm	r5,r3,16,20,31			/* Extract MAS0(Entry) */
705
706	mfspr	r7,SPRN_MAS1			/* Insure IPROT set */
707	oris	r7,r7,MAS1_IPROT@h
708	mtspr	SPRN_MAS1,r7
709	tlbwe
710
711/* 2. Invalidate all entries except the entry we're executing in
712 *
713 * r3 = MAS0 w/TLBSEL & ESEL for the entry we are running in
714 * r4 = SPRN_TLBnCFG
715 * r5 = ESEL of entry we are running in
716 */
717	andi.	r4,r4,TLBnCFG_N_ENTRY		/* Extract # entries */
718	li	r6,0				/* Set Entry counter to 0 */
7191:	mr	r7,r3				/* Set MAS0(TLBSEL) */
720	rlwimi	r7,r6,16,4,15			/* Setup MAS0 = TLBSEL | ESEL(r6) */
721	mtspr	SPRN_MAS0,r7
722	tlbre
723	mfspr	r7,SPRN_MAS1
724	rlwinm	r7,r7,0,2,31			/* Clear MAS1 Valid and IPROT */
725	cmpw	r5,r6
726	beq	skpinv				/* Dont update the current execution TLB */
727	mtspr	SPRN_MAS1,r7
728	tlbwe
729	isync
730skpinv:	addi	r6,r6,1				/* Increment */
731	cmpw	r6,r4				/* Are we done? */
732	bne	1b				/* If not, repeat */
733
734	/* Invalidate all TLBs */
735	PPC_TLBILX_ALL(0,0)
736	sync
737	isync
738
739/* 3. Setup a temp mapping and jump to it
740 *
741 * r3 = MAS0 w/TLBSEL & ESEL for the entry we are running in
742 * r5 = ESEL of entry we are running in
743 */
744	andi.	r7,r5,0x1	/* Find an entry not used and is non-zero */
745	addi	r7,r7,0x1
746	mr	r4,r3		/* Set MAS0(TLBSEL) = 1 */
747	mtspr	SPRN_MAS0,r4
748	tlbre
749
750	rlwimi	r4,r7,16,4,15	/* Setup MAS0 = TLBSEL | ESEL(r7) */
751	mtspr	SPRN_MAS0,r4
752
753	mfspr	r7,SPRN_MAS1
754	xori	r6,r7,MAS1_TS		/* Setup TMP mapping in the other Address space */
755	mtspr	SPRN_MAS1,r6
756
757	tlbwe
758
759	mfmsr	r6
760	xori	r6,r6,MSR_IS
761	mtspr	SPRN_SRR1,r6
762	bl	1f		/* Find our address */
7631:	mflr	r6
764	addi	r6,r6,(2f - 1b)
765	mtspr	SPRN_SRR0,r6
766	rfi
7672:
768
769/* 4. Clear out PIDs & Search info
770 *
771 * r3 = MAS0 w/TLBSEL & ESEL for the entry we started in
772 * r4 = MAS0 w/TLBSEL & ESEL for the temp mapping
773 * r5 = MAS3
774 */
775	li	r6,0
776	mtspr   SPRN_MAS6,r6
777	mtspr	SPRN_PID,r6
778
779/* 5. Invalidate mapping we started in
780 *
781 * r3 = MAS0 w/TLBSEL & ESEL for the entry we started in
782 * r4 = MAS0 w/TLBSEL & ESEL for the temp mapping
783 * r5 = MAS3
784 */
785	mtspr	SPRN_MAS0,r3
786	tlbre
787	mfspr	r6,SPRN_MAS1
788	rlwinm	r6,r6,0,2,0	/* clear IPROT */
789	mtspr	SPRN_MAS1,r6
790	tlbwe
791
792	/* Invalidate TLB1 */
793	PPC_TLBILX_ALL(0,0)
794	sync
795	isync
796
797/* The mapping only needs to be cache-coherent on SMP */
798#ifdef CONFIG_SMP
799#define M_IF_SMP	MAS2_M
800#else
801#define M_IF_SMP	0
802#endif
803
804/* 6. Setup KERNELBASE mapping in TLB[0]
805 *
806 * r3 = MAS0 w/TLBSEL & ESEL for the entry we started in
807 * r4 = MAS0 w/TLBSEL & ESEL for the temp mapping
808 * r5 = MAS3
809 */
810	rlwinm	r3,r3,0,16,3	/* clear ESEL */
811	mtspr	SPRN_MAS0,r3
812	lis	r6,(MAS1_VALID|MAS1_IPROT)@h
813	ori	r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_1GB))@l
814	mtspr	SPRN_MAS1,r6
815
816	LOAD_REG_IMMEDIATE(r6, PAGE_OFFSET | M_IF_SMP)
817	mtspr	SPRN_MAS2,r6
818
819	rlwinm	r5,r5,0,0,25
820	ori	r5,r5,MAS3_SR | MAS3_SW | MAS3_SX
821	mtspr	SPRN_MAS3,r5
822	li	r5,-1
823	rlwinm	r5,r5,0,0,25
824
825	tlbwe
826
827/* 7. Jump to KERNELBASE mapping
828 *
829 * r4 = MAS0 w/TLBSEL & ESEL for the temp mapping
830 */
831	/* Now we branch the new virtual address mapped by this entry */
832	LOAD_REG_IMMEDIATE(r6,2f)
833	lis	r7,MSR_KERNEL@h
834	ori	r7,r7,MSR_KERNEL@l
835	mtspr	SPRN_SRR0,r6
836	mtspr	SPRN_SRR1,r7
837	rfi				/* start execution out of TLB1[0] entry */
8382:
839
840/* 8. Clear out the temp mapping
841 *
842 * r4 = MAS0 w/TLBSEL & ESEL for the entry we are running in
843 */
844	mtspr	SPRN_MAS0,r4
845	tlbre
846	mfspr	r5,SPRN_MAS1
847	rlwinm	r5,r5,0,2,0	/* clear IPROT */
848	mtspr	SPRN_MAS1,r5
849	tlbwe
850
851	/* Invalidate TLB1 */
852	PPC_TLBILX_ALL(0,0)
853	sync
854	isync
855
856	/* We translate LR and return */
857	tovirt(r8,r8)
858	mtlr	r8
859	blr
860
861have_hes:
862	/* Setup MAS 0,1,2,3 and 7 for tlbwe of a 1G entry that maps the
863	 * kernel linear mapping. We also set MAS8 once for all here though
864	 * that will have to be made dependent on whether we are running under
865	 * a hypervisor I suppose.
866	 */
867	ori	r3,r3,MAS0_HES | MAS0_WQ_ALLWAYS
868	mtspr	SPRN_MAS0,r3
869	lis	r3,(MAS1_VALID | MAS1_IPROT)@h
870	ori	r3,r3,BOOK3E_PAGESZ_1GB << MAS1_TSIZE_SHIFT
871	mtspr	SPRN_MAS1,r3
872	LOAD_REG_IMMEDIATE(r3, PAGE_OFFSET | MAS2_M)
873	mtspr	SPRN_MAS2,r3
874	li	r3,MAS3_SR | MAS3_SW | MAS3_SX
875	mtspr	SPRN_MAS7_MAS3,r3
876	li	r3,0
877	mtspr	SPRN_MAS8,r3
878
879	/* Write the TLB entry */
880	tlbwe
881
882	/* Now we branch the new virtual address mapped by this entry */
883	LOAD_REG_IMMEDIATE(r3,1f)
884	mtctr	r3
885	bctr
886
8871:	/* We are now running at PAGE_OFFSET, clean the TLB of everything
888	 * else (XXX we should scan for bolted crap from the firmware too)
889	 */
890	PPC_TLBILX(0,0,0)
891	sync
892	isync
893
894	/* We translate LR and return */
895	mflr	r3
896	tovirt(r3,r3)
897	mtlr	r3
898	blr
899
900/*
901 * Main entry (boot CPU, thread 0)
902 *
903 * We enter here from head_64.S, possibly after the prom_init trampoline
904 * with r3 and r4 already saved to r31 and 30 respectively and in 64 bits
905 * mode. Anything else is as it was left by the bootloader
906 *
907 * Initial requirements of this port:
908 *
909 * - Kernel loaded at 0 physical
910 * - A good lump of memory mapped 0:0 by UTLB entry 0
911 * - MSR:IS & MSR:DS set to 0
912 *
913 * Note that some of the above requirements will be relaxed in the future
914 * as the kernel becomes smarter at dealing with different initial conditions
915 * but for now you have to be careful
916 */
917_GLOBAL(start_initialization_book3e)
918	mflr	r28
919
920	/* First, we need to setup some initial TLBs to map the kernel
921	 * text, data and bss at PAGE_OFFSET. We don't have a real mode
922	 * and always use AS 0, so we just set it up to match our link
923	 * address and never use 0 based addresses.
924	 */
925	bl	.initial_tlb_book3e
926
927	/* Init global core bits */
928	bl	.init_core_book3e
929
930	/* Init per-thread bits */
931	bl	.init_thread_book3e
932
933	/* Return to common init code */
934	tovirt(r28,r28)
935	mtlr	r28
936	blr
937
938
939/*
940 * Secondary core/processor entry
941 *
942 * This is entered for thread 0 of a secondary core, all other threads
943 * are expected to be stopped. It's similar to start_initialization_book3e
944 * except that it's generally entered from the holding loop in head_64.S
945 * after CPUs have been gathered by Open Firmware.
946 *
947 * We assume we are in 32 bits mode running with whatever TLB entry was
948 * set for us by the firmware or POR engine.
949 */
950_GLOBAL(book3e_secondary_core_init_tlb_set)
951	li	r4,1
952	b	.generic_secondary_smp_init
953
954_GLOBAL(book3e_secondary_core_init)
955	mflr	r28
956
957	/* Do we need to setup initial TLB entry ? */
958	cmplwi	r4,0
959	bne	2f
960
961	/* Setup TLB for this core */
962	bl	.initial_tlb_book3e
963
964	/* We can return from the above running at a different
965	 * address, so recalculate r2 (TOC)
966	 */
967	bl	.relative_toc
968
969	/* Init global core bits */
9702:	bl	.init_core_book3e
971
972	/* Init per-thread bits */
9733:	bl	.init_thread_book3e
974
975	/* Return to common init code at proper virtual address.
976	 *
977	 * Due to various previous assumptions, we know we entered this
978	 * function at either the final PAGE_OFFSET mapping or using a
979	 * 1:1 mapping at 0, so we don't bother doing a complicated check
980	 * here, we just ensure the return address has the right top bits.
981	 *
982	 * Note that if we ever want to be smarter about where we can be
983	 * started from, we have to be careful that by the time we reach
984	 * the code below we may already be running at a different location
985	 * than the one we were called from since initial_tlb_book3e can
986	 * have moved us already.
987	 */
988	cmpdi	cr0,r28,0
989	blt	1f
990	lis	r3,PAGE_OFFSET@highest
991	sldi	r3,r3,32
992	or	r28,r28,r3
9931:	mtlr	r28
994	blr
995
996_GLOBAL(book3e_secondary_thread_init)
997	mflr	r28
998	b	3b
999
1000_STATIC(init_core_book3e)
1001	/* Establish the interrupt vector base */
1002	LOAD_REG_IMMEDIATE(r3, interrupt_base_book3e)
1003	mtspr	SPRN_IVPR,r3
1004	sync
1005	blr
1006
1007_STATIC(init_thread_book3e)
1008	lis	r3,(SPRN_EPCR_ICM | SPRN_EPCR_GICM)@h
1009	mtspr	SPRN_EPCR,r3
1010
1011	/* Make sure interrupts are off */
1012	wrteei	0
1013
1014	/* disable all timers and clear out status */
1015	li	r3,0
1016	mtspr	SPRN_TCR,r3
1017	mfspr	r3,SPRN_TSR
1018	mtspr	SPRN_TSR,r3
1019
1020	blr
1021
1022_GLOBAL(__setup_base_ivors)
1023	SET_IVOR(0, 0x020) /* Critical Input */
1024	SET_IVOR(1, 0x000) /* Machine Check */
1025	SET_IVOR(2, 0x060) /* Data Storage */
1026	SET_IVOR(3, 0x080) /* Instruction Storage */
1027	SET_IVOR(4, 0x0a0) /* External Input */
1028	SET_IVOR(5, 0x0c0) /* Alignment */
1029	SET_IVOR(6, 0x0e0) /* Program */
1030	SET_IVOR(7, 0x100) /* FP Unavailable */
1031	SET_IVOR(8, 0x120) /* System Call */
1032	SET_IVOR(9, 0x140) /* Auxiliary Processor Unavailable */
1033	SET_IVOR(10, 0x160) /* Decrementer */
1034	SET_IVOR(11, 0x180) /* Fixed Interval Timer */
1035	SET_IVOR(12, 0x1a0) /* Watchdog Timer */
1036	SET_IVOR(13, 0x1c0) /* Data TLB Error */
1037	SET_IVOR(14, 0x1e0) /* Instruction TLB Error */
1038	SET_IVOR(15, 0x040) /* Debug */
1039
1040	sync
1041
1042	blr
1043