xref: /linux/arch/powerpc/kernel/exceptions-64e.S (revision 89c81797d4a0779a957f4ea1f0c676cda203615b)
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#define	EXCEPTION_STUB(loc, label)					\
195	. = interrupt_base_book3e + loc;				\
196	nop;	/* To make debug interrupts happy */			\
197	b	exc_##label##_book3e;
198
199#define ACK_NONE(r)
200#define ACK_DEC(r)							\
201	lis	r,TSR_DIS@h;						\
202	mtspr	SPRN_TSR,r
203#define ACK_FIT(r)							\
204	lis	r,TSR_FIS@h;						\
205	mtspr	SPRN_TSR,r
206
207#define MASKABLE_EXCEPTION(trapnum, label, hdlr, ack)			\
208	START_EXCEPTION(label);						\
209	NORMAL_EXCEPTION_PROLOG(trapnum, PROLOG_ADDITION_MASKABLE)	\
210	EXCEPTION_COMMON(trapnum, PACA_EXGEN, INTS_DISABLE_ALL)		\
211	ack(r8);							\
212	addi	r3,r1,STACK_FRAME_OVERHEAD;				\
213	bl	hdlr;							\
214	b	.ret_from_except_lite;
215
216/* This value is used to mark exception frames on the stack. */
217	.section	".toc","aw"
218exception_marker:
219	.tc	ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER
220
221
222/*
223 * And here we have the exception vectors !
224 */
225
226	.text
227	.balign	0x1000
228	.globl interrupt_base_book3e
229interrupt_base_book3e:					/* fake trap */
230	/* Note: If real debug exceptions are supported by the HW, the vector
231	 * below will have to be patched up to point to an appropriate handler
232	 */
233	EXCEPTION_STUB(0x000, machine_check)		/* 0x0200 */
234	EXCEPTION_STUB(0x020, critical_input)		/* 0x0580 */
235	EXCEPTION_STUB(0x040, debug_crit)		/* 0x0d00 */
236	EXCEPTION_STUB(0x060, data_storage)		/* 0x0300 */
237	EXCEPTION_STUB(0x080, instruction_storage)	/* 0x0400 */
238	EXCEPTION_STUB(0x0a0, external_input)		/* 0x0500 */
239	EXCEPTION_STUB(0x0c0, alignment)		/* 0x0600 */
240	EXCEPTION_STUB(0x0e0, program)			/* 0x0700 */
241	EXCEPTION_STUB(0x100, fp_unavailable)		/* 0x0800 */
242	EXCEPTION_STUB(0x120, system_call)		/* 0x0c00 */
243	EXCEPTION_STUB(0x140, ap_unavailable)		/* 0x0f20 */
244	EXCEPTION_STUB(0x160, decrementer)		/* 0x0900 */
245	EXCEPTION_STUB(0x180, fixed_interval)		/* 0x0980 */
246	EXCEPTION_STUB(0x1a0, watchdog)			/* 0x09f0 */
247	EXCEPTION_STUB(0x1c0, data_tlb_miss)
248	EXCEPTION_STUB(0x1e0, instruction_tlb_miss)
249	EXCEPTION_STUB(0x280, doorbell)
250	EXCEPTION_STUB(0x2a0, doorbell_crit)
251
252	.globl interrupt_end_book3e
253interrupt_end_book3e:
254
255/* Critical Input Interrupt */
256	START_EXCEPTION(critical_input);
257	CRIT_EXCEPTION_PROLOG(0x100, PROLOG_ADDITION_NONE)
258//	EXCEPTION_COMMON(0x100, PACA_EXCRIT, INTS_DISABLE_ALL)
259//	bl	special_reg_save_crit
260//	addi	r3,r1,STACK_FRAME_OVERHEAD
261//	bl	.critical_exception
262//	b	ret_from_crit_except
263	b	.
264
265/* Machine Check Interrupt */
266	START_EXCEPTION(machine_check);
267	CRIT_EXCEPTION_PROLOG(0x200, PROLOG_ADDITION_NONE)
268//	EXCEPTION_COMMON(0x200, PACA_EXMC, INTS_DISABLE_ALL)
269//	bl	special_reg_save_mc
270//	addi	r3,r1,STACK_FRAME_OVERHEAD
271//	bl	.machine_check_exception
272//	b	ret_from_mc_except
273	b	.
274
275/* Data Storage Interrupt */
276	START_EXCEPTION(data_storage)
277	NORMAL_EXCEPTION_PROLOG(0x300, PROLOG_ADDITION_2REGS)
278	mfspr	r14,SPRN_DEAR
279	mfspr	r15,SPRN_ESR
280	EXCEPTION_COMMON(0x300, PACA_EXGEN, INTS_KEEP)
281	b	storage_fault_common
282
283/* Instruction Storage Interrupt */
284	START_EXCEPTION(instruction_storage);
285	NORMAL_EXCEPTION_PROLOG(0x400, PROLOG_ADDITION_2REGS)
286	li	r15,0
287	mr	r14,r10
288	EXCEPTION_COMMON(0x400, PACA_EXGEN, INTS_KEEP)
289	b	storage_fault_common
290
291/* External Input Interrupt */
292	MASKABLE_EXCEPTION(0x500, external_input, .do_IRQ, ACK_NONE)
293
294/* Alignment */
295	START_EXCEPTION(alignment);
296	NORMAL_EXCEPTION_PROLOG(0x600, PROLOG_ADDITION_2REGS)
297	mfspr	r14,SPRN_DEAR
298	mfspr	r15,SPRN_ESR
299	EXCEPTION_COMMON(0x600, PACA_EXGEN, INTS_KEEP)
300	b	alignment_more	/* no room, go out of line */
301
302/* Program Interrupt */
303	START_EXCEPTION(program);
304	NORMAL_EXCEPTION_PROLOG(0x700, PROLOG_ADDITION_1REG)
305	mfspr	r14,SPRN_ESR
306	EXCEPTION_COMMON(0x700, PACA_EXGEN, INTS_DISABLE_SOFT)
307	std	r14,_DSISR(r1)
308	addi	r3,r1,STACK_FRAME_OVERHEAD
309	ld	r14,PACA_EXGEN+EX_R14(r13)
310	bl	.save_nvgprs
311	INTS_RESTORE_HARD
312	bl	.program_check_exception
313	b	.ret_from_except
314
315/* Floating Point Unavailable Interrupt */
316	START_EXCEPTION(fp_unavailable);
317	NORMAL_EXCEPTION_PROLOG(0x800, PROLOG_ADDITION_NONE)
318	/* we can probably do a shorter exception entry for that one... */
319	EXCEPTION_COMMON(0x800, PACA_EXGEN, INTS_KEEP)
320	bne	1f			/* if from user, just load it up */
321	bl	.save_nvgprs
322	addi	r3,r1,STACK_FRAME_OVERHEAD
323	INTS_RESTORE_HARD
324	bl	.kernel_fp_unavailable_exception
325	BUG_OPCODE
3261:	ld	r12,_MSR(r1)
327	bl	.load_up_fpu
328	b	fast_exception_return
329
330/* Decrementer Interrupt */
331	MASKABLE_EXCEPTION(0x900, decrementer, .timer_interrupt, ACK_DEC)
332
333/* Fixed Interval Timer Interrupt */
334	MASKABLE_EXCEPTION(0x980, fixed_interval, .unknown_exception, ACK_FIT)
335
336/* Watchdog Timer Interrupt */
337	START_EXCEPTION(watchdog);
338	CRIT_EXCEPTION_PROLOG(0x9f0, PROLOG_ADDITION_NONE)
339//	EXCEPTION_COMMON(0x9f0, PACA_EXCRIT, INTS_DISABLE_ALL)
340//	bl	special_reg_save_crit
341//	addi	r3,r1,STACK_FRAME_OVERHEAD
342//	bl	.unknown_exception
343//	b	ret_from_crit_except
344	b	.
345
346/* System Call Interrupt */
347	START_EXCEPTION(system_call)
348	mr	r9,r13			/* keep a copy of userland r13 */
349	mfspr	r11,SPRN_SRR0		/* get return address */
350	mfspr	r12,SPRN_SRR1		/* get previous MSR */
351	mfspr	r13,SPRN_SPRG_PACA	/* get our PACA */
352	b	system_call_common
353
354/* Auxillary Processor Unavailable Interrupt */
355	START_EXCEPTION(ap_unavailable);
356	NORMAL_EXCEPTION_PROLOG(0xf20, PROLOG_ADDITION_NONE)
357	EXCEPTION_COMMON(0xf20, PACA_EXGEN, INTS_KEEP)
358	addi	r3,r1,STACK_FRAME_OVERHEAD
359	bl	.save_nvgprs
360	INTS_RESTORE_HARD
361	bl	.unknown_exception
362	b	.ret_from_except
363
364/* Debug exception as a critical interrupt*/
365	START_EXCEPTION(debug_crit);
366	CRIT_EXCEPTION_PROLOG(0xd00, PROLOG_ADDITION_2REGS)
367
368	/*
369	 * If there is a single step or branch-taken exception in an
370	 * exception entry sequence, it was probably meant to apply to
371	 * the code where the exception occurred (since exception entry
372	 * doesn't turn off DE automatically).  We simulate the effect
373	 * of turning off DE on entry to an exception handler by turning
374	 * off DE in the CSRR1 value and clearing the debug status.
375	 */
376
377	mfspr	r14,SPRN_DBSR		/* check single-step/branch taken */
378	andis.	r15,r14,DBSR_IC@h
379	beq+	1f
380
381	LOAD_REG_IMMEDIATE(r14,interrupt_base_book3e)
382	LOAD_REG_IMMEDIATE(r15,interrupt_end_book3e)
383	cmpld	cr0,r10,r14
384	cmpld	cr1,r10,r15
385	blt+	cr0,1f
386	bge+	cr1,1f
387
388	/* here it looks like we got an inappropriate debug exception. */
389	lis	r14,DBSR_IC@h		/* clear the IC event */
390	rlwinm	r11,r11,0,~MSR_DE	/* clear DE in the CSRR1 value */
391	mtspr	SPRN_DBSR,r14
392	mtspr	SPRN_CSRR1,r11
393	lwz	r10,PACA_EXCRIT+EX_CR(r13)	/* restore registers */
394	ld	r1,PACA_EXCRIT+EX_R1(r13)
395	ld	r14,PACA_EXCRIT+EX_R14(r13)
396	ld	r15,PACA_EXCRIT+EX_R15(r13)
397	mtcr	r10
398	ld	r10,PACA_EXCRIT+EX_R10(r13)	/* restore registers */
399	ld	r11,PACA_EXCRIT+EX_R11(r13)
400	mfspr	r13,SPRN_SPRG_CRIT_SCRATCH
401	rfci
402
403	/* Normal debug exception */
404	/* XXX We only handle coming from userspace for now since we can't
405	 *     quite save properly an interrupted kernel state yet
406	 */
4071:	andi.	r14,r11,MSR_PR;		/* check for userspace again */
408	beq	kernel_dbg_exc;		/* if from kernel mode */
409
410	/* Now we mash up things to make it look like we are coming on a
411	 * normal exception
412	 */
413	mfspr	r15,SPRN_SPRG_CRIT_SCRATCH
414	mtspr	SPRN_SPRG_GEN_SCRATCH,r15
415	mfspr	r14,SPRN_DBSR
416	EXCEPTION_COMMON(0xd00, PACA_EXCRIT, INTS_DISABLE_ALL)
417	std	r14,_DSISR(r1)
418	addi	r3,r1,STACK_FRAME_OVERHEAD
419	mr	r4,r14
420	ld	r14,PACA_EXCRIT+EX_R14(r13)
421	ld	r15,PACA_EXCRIT+EX_R15(r13)
422	bl	.save_nvgprs
423	bl	.DebugException
424	b	.ret_from_except
425
426kernel_dbg_exc:
427	b	.	/* NYI */
428
429/* Doorbell interrupt */
430	MASKABLE_EXCEPTION(0x2070, doorbell, .doorbell_exception, ACK_NONE)
431
432/* Doorbell critical Interrupt */
433	START_EXCEPTION(doorbell_crit);
434	CRIT_EXCEPTION_PROLOG(0x2080, PROLOG_ADDITION_NONE)
435//	EXCEPTION_COMMON(0x2080, PACA_EXCRIT, INTS_DISABLE_ALL)
436//	bl	special_reg_save_crit
437//	addi	r3,r1,STACK_FRAME_OVERHEAD
438//	bl	.doorbell_critical_exception
439//	b	ret_from_crit_except
440	b	.
441
442
443/*
444 * An interrupt came in while soft-disabled; clear EE in SRR1,
445 * clear paca->hard_enabled and return.
446 */
447masked_interrupt_book3e:
448	mtcr	r10
449	stb	r11,PACAHARDIRQEN(r13)
450	mfspr	r10,SPRN_SRR1
451	rldicl	r11,r10,48,1		/* clear MSR_EE */
452	rotldi	r10,r11,16
453	mtspr	SPRN_SRR1,r10
454	ld	r10,PACA_EXGEN+EX_R10(r13);	/* restore registers */
455	ld	r11,PACA_EXGEN+EX_R11(r13);
456	mfspr	r13,SPRN_SPRG_GEN_SCRATCH;
457	rfi
458	b	.
459
460/*
461 * This is called from 0x300 and 0x400 handlers after the prologs with
462 * r14 and r15 containing the fault address and error code, with the
463 * original values stashed away in the PACA
464 */
465storage_fault_common:
466	std	r14,_DAR(r1)
467	std	r15,_DSISR(r1)
468	addi	r3,r1,STACK_FRAME_OVERHEAD
469	mr	r4,r14
470	mr	r5,r15
471	ld	r14,PACA_EXGEN+EX_R14(r13)
472	ld	r15,PACA_EXGEN+EX_R15(r13)
473	INTS_RESTORE_HARD
474	bl	.do_page_fault
475	cmpdi	r3,0
476	bne-	1f
477	b	.ret_from_except_lite
4781:	bl	.save_nvgprs
479	mr	r5,r3
480	addi	r3,r1,STACK_FRAME_OVERHEAD
481	ld	r4,_DAR(r1)
482	bl	.bad_page_fault
483	b	.ret_from_except
484
485/*
486 * Alignment exception doesn't fit entirely in the 0x100 bytes so it
487 * continues here.
488 */
489alignment_more:
490	std	r14,_DAR(r1)
491	std	r15,_DSISR(r1)
492	addi	r3,r1,STACK_FRAME_OVERHEAD
493	ld	r14,PACA_EXGEN+EX_R14(r13)
494	ld	r15,PACA_EXGEN+EX_R15(r13)
495	bl	.save_nvgprs
496	INTS_RESTORE_HARD
497	bl	.alignment_exception
498	b	.ret_from_except
499
500/*
501 * We branch here from entry_64.S for the last stage of the exception
502 * return code path. MSR:EE is expected to be off at that point
503 */
504_GLOBAL(exception_return_book3e)
505	b	1f
506
507/* This is the return from load_up_fpu fast path which could do with
508 * less GPR restores in fact, but for now we have a single return path
509 */
510	.globl fast_exception_return
511fast_exception_return:
512	wrteei	0
5131:	mr	r0,r13
514	ld	r10,_MSR(r1)
515	REST_4GPRS(2, r1)
516	andi.	r6,r10,MSR_PR
517	REST_2GPRS(6, r1)
518	beq	1f
519	ACCOUNT_CPU_USER_EXIT(r10, r11)
520	ld	r0,GPR13(r1)
521
5221:	stdcx.	r0,0,r1		/* to clear the reservation */
523
524	ld	r8,_CCR(r1)
525	ld	r9,_LINK(r1)
526	ld	r10,_CTR(r1)
527	ld	r11,_XER(r1)
528	mtcr	r8
529	mtlr	r9
530	mtctr	r10
531	mtxer	r11
532	REST_2GPRS(8, r1)
533	ld	r10,GPR10(r1)
534	ld	r11,GPR11(r1)
535	ld	r12,GPR12(r1)
536	mtspr	SPRN_SPRG_GEN_SCRATCH,r0
537
538	std	r10,PACA_EXGEN+EX_R10(r13);
539	std	r11,PACA_EXGEN+EX_R11(r13);
540	ld	r10,_NIP(r1)
541	ld	r11,_MSR(r1)
542	ld	r0,GPR0(r1)
543	ld	r1,GPR1(r1)
544	mtspr	SPRN_SRR0,r10
545	mtspr	SPRN_SRR1,r11
546	ld	r10,PACA_EXGEN+EX_R10(r13)
547	ld	r11,PACA_EXGEN+EX_R11(r13)
548	mfspr	r13,SPRN_SPRG_GEN_SCRATCH
549	rfi
550
551/*
552 * Trampolines used when spotting a bad kernel stack pointer in
553 * the exception entry code.
554 *
555 * TODO: move some bits like SRR0 read to trampoline, pass PACA
556 * index around, etc... to handle crit & mcheck
557 */
558BAD_STACK_TRAMPOLINE(0x000)
559BAD_STACK_TRAMPOLINE(0x100)
560BAD_STACK_TRAMPOLINE(0x200)
561BAD_STACK_TRAMPOLINE(0x300)
562BAD_STACK_TRAMPOLINE(0x400)
563BAD_STACK_TRAMPOLINE(0x500)
564BAD_STACK_TRAMPOLINE(0x600)
565BAD_STACK_TRAMPOLINE(0x700)
566BAD_STACK_TRAMPOLINE(0x800)
567BAD_STACK_TRAMPOLINE(0x900)
568BAD_STACK_TRAMPOLINE(0x980)
569BAD_STACK_TRAMPOLINE(0x9f0)
570BAD_STACK_TRAMPOLINE(0xa00)
571BAD_STACK_TRAMPOLINE(0xb00)
572BAD_STACK_TRAMPOLINE(0xc00)
573BAD_STACK_TRAMPOLINE(0xd00)
574BAD_STACK_TRAMPOLINE(0xe00)
575BAD_STACK_TRAMPOLINE(0xf00)
576BAD_STACK_TRAMPOLINE(0xf20)
577BAD_STACK_TRAMPOLINE(0x2070)
578BAD_STACK_TRAMPOLINE(0x2080)
579
580	.globl	bad_stack_book3e
581bad_stack_book3e:
582	/* XXX: Needs to make SPRN_SPRG_GEN depend on exception type */
583	mfspr	r10,SPRN_SRR0;		  /* read SRR0 before touching stack */
584	ld	r1,PACAEMERGSP(r13)
585	subi	r1,r1,64+INT_FRAME_SIZE
586	std	r10,_NIP(r1)
587	std	r11,_MSR(r1)
588	ld	r10,PACA_EXGEN+EX_R1(r13) /* FIXME for crit & mcheck */
589	lwz	r11,PACA_EXGEN+EX_CR(r13) /* FIXME for crit & mcheck */
590	std	r10,GPR1(r1)
591	std	r11,_CCR(r1)
592	mfspr	r10,SPRN_DEAR
593	mfspr	r11,SPRN_ESR
594	std	r10,_DAR(r1)
595	std	r11,_DSISR(r1)
596	std	r0,GPR0(r1);		/* save r0 in stackframe */	    \
597	std	r2,GPR2(r1);		/* save r2 in stackframe */	    \
598	SAVE_4GPRS(3, r1);		/* save r3 - r6 in stackframe */    \
599	SAVE_2GPRS(7, r1);		/* save r7, r8 in stackframe */	    \
600	std	r9,GPR9(r1);		/* save r9 in stackframe */	    \
601	ld	r3,PACA_EXGEN+EX_R10(r13);/* get back r10 */		    \
602	ld	r4,PACA_EXGEN+EX_R11(r13);/* get back r11 */		    \
603	mfspr	r5,SPRN_SPRG_GEN_SCRATCH;/* get back r13 XXX can be wrong */ \
604	std	r3,GPR10(r1);		/* save r10 to stackframe */	    \
605	std	r4,GPR11(r1);		/* save r11 to stackframe */	    \
606	std	r12,GPR12(r1);		/* save r12 in stackframe */	    \
607	std	r5,GPR13(r1);		/* save it to stackframe */	    \
608	mflr	r10
609	mfctr	r11
610	mfxer	r12
611	std	r10,_LINK(r1)
612	std	r11,_CTR(r1)
613	std	r12,_XER(r1)
614	SAVE_10GPRS(14,r1)
615	SAVE_8GPRS(24,r1)
616	lhz	r12,PACA_TRAP_SAVE(r13)
617	std	r12,_TRAP(r1)
618	addi	r11,r1,INT_FRAME_SIZE
619	std	r11,0(r1)
620	li	r12,0
621	std	r12,0(r11)
622	ld	r2,PACATOC(r13)
6231:	addi	r3,r1,STACK_FRAME_OVERHEAD
624	bl	.kernel_bad_stack
625	b	1b
626
627/*
628 * Setup the initial TLB for a core. This current implementation
629 * assume that whatever we are running off will not conflict with
630 * the new mapping at PAGE_OFFSET.
631 */
632_GLOBAL(initial_tlb_book3e)
633
634	/* Look for the first TLB with IPROT set */
635	mfspr	r4,SPRN_TLB0CFG
636	andi.	r3,r4,TLBnCFG_IPROT
637	lis	r3,MAS0_TLBSEL(0)@h
638	bne	found_iprot
639
640	mfspr	r4,SPRN_TLB1CFG
641	andi.	r3,r4,TLBnCFG_IPROT
642	lis	r3,MAS0_TLBSEL(1)@h
643	bne	found_iprot
644
645	mfspr	r4,SPRN_TLB2CFG
646	andi.	r3,r4,TLBnCFG_IPROT
647	lis	r3,MAS0_TLBSEL(2)@h
648	bne	found_iprot
649
650	lis	r3,MAS0_TLBSEL(3)@h
651	mfspr	r4,SPRN_TLB3CFG
652	/* fall through */
653
654found_iprot:
655	andi.	r5,r4,TLBnCFG_HES
656	bne	have_hes
657
658	mflr	r8				/* save LR */
659/* 1. Find the index of the entry we're executing in
660 *
661 * r3 = MAS0_TLBSEL (for the iprot array)
662 * r4 = SPRN_TLBnCFG
663 */
664	bl	invstr				/* Find our address */
665invstr:	mflr	r6				/* Make it accessible */
666	mfmsr	r7
667	rlwinm	r5,r7,27,31,31			/* extract MSR[IS] */
668	mfspr	r7,SPRN_PID
669	slwi	r7,r7,16
670	or	r7,r7,r5
671	mtspr	SPRN_MAS6,r7
672	tlbsx	0,r6				/* search MSR[IS], SPID=PID */
673
674	mfspr	r3,SPRN_MAS0
675	rlwinm	r5,r3,16,20,31			/* Extract MAS0(Entry) */
676
677	mfspr	r7,SPRN_MAS1			/* Insure IPROT set */
678	oris	r7,r7,MAS1_IPROT@h
679	mtspr	SPRN_MAS1,r7
680	tlbwe
681
682/* 2. Invalidate all entries except the entry we're executing in
683 *
684 * r3 = MAS0 w/TLBSEL & ESEL for the entry we are running in
685 * r4 = SPRN_TLBnCFG
686 * r5 = ESEL of entry we are running in
687 */
688	andi.	r4,r4,TLBnCFG_N_ENTRY		/* Extract # entries */
689	li	r6,0				/* Set Entry counter to 0 */
6901:	mr	r7,r3				/* Set MAS0(TLBSEL) */
691	rlwimi	r7,r6,16,4,15			/* Setup MAS0 = TLBSEL | ESEL(r6) */
692	mtspr	SPRN_MAS0,r7
693	tlbre
694	mfspr	r7,SPRN_MAS1
695	rlwinm	r7,r7,0,2,31			/* Clear MAS1 Valid and IPROT */
696	cmpw	r5,r6
697	beq	skpinv				/* Dont update the current execution TLB */
698	mtspr	SPRN_MAS1,r7
699	tlbwe
700	isync
701skpinv:	addi	r6,r6,1				/* Increment */
702	cmpw	r6,r4				/* Are we done? */
703	bne	1b				/* If not, repeat */
704
705	/* Invalidate all TLBs */
706	PPC_TLBILX_ALL(0,0)
707	sync
708	isync
709
710/* 3. Setup a temp mapping and jump to it
711 *
712 * r3 = MAS0 w/TLBSEL & ESEL for the entry we are running in
713 * r5 = ESEL of entry we are running in
714 */
715	andi.	r7,r5,0x1	/* Find an entry not used and is non-zero */
716	addi	r7,r7,0x1
717	mr	r4,r3		/* Set MAS0(TLBSEL) = 1 */
718	mtspr	SPRN_MAS0,r4
719	tlbre
720
721	rlwimi	r4,r7,16,4,15	/* Setup MAS0 = TLBSEL | ESEL(r7) */
722	mtspr	SPRN_MAS0,r4
723
724	mfspr	r7,SPRN_MAS1
725	xori	r6,r7,MAS1_TS		/* Setup TMP mapping in the other Address space */
726	mtspr	SPRN_MAS1,r6
727
728	tlbwe
729
730	mfmsr	r6
731	xori	r6,r6,MSR_IS
732	mtspr	SPRN_SRR1,r6
733	bl	1f		/* Find our address */
7341:	mflr	r6
735	addi	r6,r6,(2f - 1b)
736	mtspr	SPRN_SRR0,r6
737	rfi
7382:
739
740/* 4. Clear out PIDs & Search info
741 *
742 * r3 = MAS0 w/TLBSEL & ESEL for the entry we started in
743 * r4 = MAS0 w/TLBSEL & ESEL for the temp mapping
744 * r5 = MAS3
745 */
746	li	r6,0
747	mtspr   SPRN_MAS6,r6
748	mtspr	SPRN_PID,r6
749
750/* 5. Invalidate mapping we started in
751 *
752 * r3 = MAS0 w/TLBSEL & ESEL for the entry we started in
753 * r4 = MAS0 w/TLBSEL & ESEL for the temp mapping
754 * r5 = MAS3
755 */
756	mtspr	SPRN_MAS0,r3
757	tlbre
758	mfspr	r6,SPRN_MAS1
759	rlwinm	r6,r6,0,2,0	/* clear IPROT */
760	mtspr	SPRN_MAS1,r6
761	tlbwe
762
763	/* Invalidate TLB1 */
764	PPC_TLBILX_ALL(0,0)
765	sync
766	isync
767
768/* The mapping only needs to be cache-coherent on SMP */
769#ifdef CONFIG_SMP
770#define M_IF_SMP	MAS2_M
771#else
772#define M_IF_SMP	0
773#endif
774
775/* 6. Setup KERNELBASE mapping in TLB[0]
776 *
777 * r3 = MAS0 w/TLBSEL & ESEL for the entry we started in
778 * r4 = MAS0 w/TLBSEL & ESEL for the temp mapping
779 * r5 = MAS3
780 */
781	rlwinm	r3,r3,0,16,3	/* clear ESEL */
782	mtspr	SPRN_MAS0,r3
783	lis	r6,(MAS1_VALID|MAS1_IPROT)@h
784	ori	r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_1GB))@l
785	mtspr	SPRN_MAS1,r6
786
787	LOAD_REG_IMMEDIATE(r6, PAGE_OFFSET | M_IF_SMP)
788	mtspr	SPRN_MAS2,r6
789
790	rlwinm	r5,r5,0,0,25
791	ori	r5,r5,MAS3_SR | MAS3_SW | MAS3_SX
792	mtspr	SPRN_MAS3,r5
793	li	r5,-1
794	rlwinm	r5,r5,0,0,25
795
796	tlbwe
797
798/* 7. Jump to KERNELBASE mapping
799 *
800 * r4 = MAS0 w/TLBSEL & ESEL for the temp mapping
801 */
802	/* Now we branch the new virtual address mapped by this entry */
803	LOAD_REG_IMMEDIATE(r6,2f)
804	lis	r7,MSR_KERNEL@h
805	ori	r7,r7,MSR_KERNEL@l
806	mtspr	SPRN_SRR0,r6
807	mtspr	SPRN_SRR1,r7
808	rfi				/* start execution out of TLB1[0] entry */
8092:
810
811/* 8. Clear out the temp mapping
812 *
813 * r4 = MAS0 w/TLBSEL & ESEL for the entry we are running in
814 */
815	mtspr	SPRN_MAS0,r4
816	tlbre
817	mfspr	r5,SPRN_MAS1
818	rlwinm	r5,r5,0,2,0	/* clear IPROT */
819	mtspr	SPRN_MAS1,r5
820	tlbwe
821
822	/* Invalidate TLB1 */
823	PPC_TLBILX_ALL(0,0)
824	sync
825	isync
826
827	/* We translate LR and return */
828	tovirt(r8,r8)
829	mtlr	r8
830	blr
831
832have_hes:
833	/* Setup MAS 0,1,2,3 and 7 for tlbwe of a 1G entry that maps the
834	 * kernel linear mapping. We also set MAS8 once for all here though
835	 * that will have to be made dependent on whether we are running under
836	 * a hypervisor I suppose.
837	 */
838	ori	r3,r3,MAS0_HES | MAS0_WQ_ALLWAYS
839	mtspr	SPRN_MAS0,r3
840	lis	r3,(MAS1_VALID | MAS1_IPROT)@h
841	ori	r3,r3,BOOK3E_PAGESZ_1GB << MAS1_TSIZE_SHIFT
842	mtspr	SPRN_MAS1,r3
843	LOAD_REG_IMMEDIATE(r3, PAGE_OFFSET | MAS2_M)
844	mtspr	SPRN_MAS2,r3
845	li	r3,MAS3_SR | MAS3_SW | MAS3_SX
846	mtspr	SPRN_MAS7_MAS3,r3
847	li	r3,0
848	mtspr	SPRN_MAS8,r3
849
850	/* Write the TLB entry */
851	tlbwe
852
853	/* Now we branch the new virtual address mapped by this entry */
854	LOAD_REG_IMMEDIATE(r3,1f)
855	mtctr	r3
856	bctr
857
8581:	/* We are now running at PAGE_OFFSET, clean the TLB of everything
859	 * else (XXX we should scan for bolted crap from the firmware too)
860	 */
861	PPC_TLBILX(0,0,0)
862	sync
863	isync
864
865	/* We translate LR and return */
866	mflr	r3
867	tovirt(r3,r3)
868	mtlr	r3
869	blr
870
871/*
872 * Main entry (boot CPU, thread 0)
873 *
874 * We enter here from head_64.S, possibly after the prom_init trampoline
875 * with r3 and r4 already saved to r31 and 30 respectively and in 64 bits
876 * mode. Anything else is as it was left by the bootloader
877 *
878 * Initial requirements of this port:
879 *
880 * - Kernel loaded at 0 physical
881 * - A good lump of memory mapped 0:0 by UTLB entry 0
882 * - MSR:IS & MSR:DS set to 0
883 *
884 * Note that some of the above requirements will be relaxed in the future
885 * as the kernel becomes smarter at dealing with different initial conditions
886 * but for now you have to be careful
887 */
888_GLOBAL(start_initialization_book3e)
889	mflr	r28
890
891	/* First, we need to setup some initial TLBs to map the kernel
892	 * text, data and bss at PAGE_OFFSET. We don't have a real mode
893	 * and always use AS 0, so we just set it up to match our link
894	 * address and never use 0 based addresses.
895	 */
896	bl	.initial_tlb_book3e
897
898	/* Init global core bits */
899	bl	.init_core_book3e
900
901	/* Init per-thread bits */
902	bl	.init_thread_book3e
903
904	/* Return to common init code */
905	tovirt(r28,r28)
906	mtlr	r28
907	blr
908
909
910/*
911 * Secondary core/processor entry
912 *
913 * This is entered for thread 0 of a secondary core, all other threads
914 * are expected to be stopped. It's similar to start_initialization_book3e
915 * except that it's generally entered from the holding loop in head_64.S
916 * after CPUs have been gathered by Open Firmware.
917 *
918 * We assume we are in 32 bits mode running with whatever TLB entry was
919 * set for us by the firmware or POR engine.
920 */
921_GLOBAL(book3e_secondary_core_init_tlb_set)
922	li	r4,1
923	b	.generic_secondary_smp_init
924
925_GLOBAL(book3e_secondary_core_init)
926	mflr	r28
927
928	/* Do we need to setup initial TLB entry ? */
929	cmplwi	r4,0
930	bne	2f
931
932	/* Setup TLB for this core */
933	bl	.initial_tlb_book3e
934
935	/* We can return from the above running at a different
936	 * address, so recalculate r2 (TOC)
937	 */
938	bl	.relative_toc
939
940	/* Init global core bits */
9412:	bl	.init_core_book3e
942
943	/* Init per-thread bits */
9443:	bl	.init_thread_book3e
945
946	/* Return to common init code at proper virtual address.
947	 *
948	 * Due to various previous assumptions, we know we entered this
949	 * function at either the final PAGE_OFFSET mapping or using a
950	 * 1:1 mapping at 0, so we don't bother doing a complicated check
951	 * here, we just ensure the return address has the right top bits.
952	 *
953	 * Note that if we ever want to be smarter about where we can be
954	 * started from, we have to be careful that by the time we reach
955	 * the code below we may already be running at a different location
956	 * than the one we were called from since initial_tlb_book3e can
957	 * have moved us already.
958	 */
959	cmpdi	cr0,r28,0
960	blt	1f
961	lis	r3,PAGE_OFFSET@highest
962	sldi	r3,r3,32
963	or	r28,r28,r3
9641:	mtlr	r28
965	blr
966
967_GLOBAL(book3e_secondary_thread_init)
968	mflr	r28
969	b	3b
970
971_STATIC(init_core_book3e)
972	/* Establish the interrupt vector base */
973	LOAD_REG_IMMEDIATE(r3, interrupt_base_book3e)
974	mtspr	SPRN_IVPR,r3
975	sync
976	blr
977
978_STATIC(init_thread_book3e)
979	lis	r3,(SPRN_EPCR_ICM | SPRN_EPCR_GICM)@h
980	mtspr	SPRN_EPCR,r3
981
982	/* Make sure interrupts are off */
983	wrteei	0
984
985	/* disable all timers and clear out status */
986	li	r3,0
987	mtspr	SPRN_TCR,r3
988	mfspr	r3,SPRN_TSR
989	mtspr	SPRN_TSR,r3
990
991	blr
992
993_GLOBAL(__setup_base_ivors)
994	SET_IVOR(0, 0x020) /* Critical Input */
995	SET_IVOR(1, 0x000) /* Machine Check */
996	SET_IVOR(2, 0x060) /* Data Storage */
997	SET_IVOR(3, 0x080) /* Instruction Storage */
998	SET_IVOR(4, 0x0a0) /* External Input */
999	SET_IVOR(5, 0x0c0) /* Alignment */
1000	SET_IVOR(6, 0x0e0) /* Program */
1001	SET_IVOR(7, 0x100) /* FP Unavailable */
1002	SET_IVOR(8, 0x120) /* System Call */
1003	SET_IVOR(9, 0x140) /* Auxiliary Processor Unavailable */
1004	SET_IVOR(10, 0x160) /* Decrementer */
1005	SET_IVOR(11, 0x180) /* Fixed Interval Timer */
1006	SET_IVOR(12, 0x1a0) /* Watchdog Timer */
1007	SET_IVOR(13, 0x1c0) /* Data TLB Error */
1008	SET_IVOR(14, 0x1e0) /* Instruction TLB Error */
1009	SET_IVOR(15, 0x040) /* Debug */
1010
1011	sync
1012
1013	blr
1014