xref: /linux/arch/powerpc/kernel/exceptions-64e.S (revision 27258e448eb301cf89e351df87aa8cb916653bf2)
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/reg.h>
21#include <asm/exception-64e.h>
22#include <asm/bug.h>
23#include <asm/irqflags.h>
24#include <asm/ptrace.h>
25#include <asm/ppc-opcode.h>
26#include <asm/mmu.h>
27
28/* XXX This will ultimately add space for a special exception save
29 *     structure used to save things like SRR0/SRR1, SPRGs, MAS, etc...
30 *     when taking special interrupts. For now we don't support that,
31 *     special interrupts from within a non-standard level will probably
32 *     blow you up
33 */
34#define	SPECIAL_EXC_FRAME_SIZE	INT_FRAME_SIZE
35
36/* Exception prolog code for all exceptions */
37#define EXCEPTION_PROLOG(n, type, addition)				    \
38	mtspr	SPRN_SPRG_##type##_SCRATCH,r13;	/* get spare registers */   \
39	mfspr	r13,SPRN_SPRG_PACA;	/* get PACA */			    \
40	std	r10,PACA_EX##type+EX_R10(r13);				    \
41	std	r11,PACA_EX##type+EX_R11(r13);				    \
42	mfcr	r10;			/* save CR */			    \
43	addition;			/* additional code for that exc. */ \
44	std	r1,PACA_EX##type+EX_R1(r13); /* save old r1 in the PACA */  \
45	stw	r10,PACA_EX##type+EX_CR(r13); /* save old CR in the PACA */ \
46	mfspr	r11,SPRN_##type##_SRR1;/* what are we coming from */	    \
47	type##_SET_KSTACK;		/* get special stack if necessary */\
48	andi.	r10,r11,MSR_PR;		/* save stack pointer */	    \
49	beq	1f;			/* branch around if supervisor */   \
50	ld	r1,PACAKSAVE(r13);	/* get kernel stack coming from usr */\
511:	cmpdi	cr1,r1,0;		/* check if SP makes sense */	    \
52	bge-	cr1,exc_##n##_bad_stack;/* bad stack (TODO: out of line) */ \
53	mfspr	r10,SPRN_##type##_SRR0;	/* read SRR0 before touching stack */
54
55/* Exception type-specific macros */
56#define	GEN_SET_KSTACK							    \
57	subi	r1,r1,INT_FRAME_SIZE;	/* alloc frame on kernel stack */
58#define SPRN_GEN_SRR0	SPRN_SRR0
59#define SPRN_GEN_SRR1	SPRN_SRR1
60
61#define CRIT_SET_KSTACK						            \
62	ld	r1,PACA_CRIT_STACK(r13);				    \
63	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
64#define SPRN_CRIT_SRR0	SPRN_CSRR0
65#define SPRN_CRIT_SRR1	SPRN_CSRR1
66
67#define DBG_SET_KSTACK						            \
68	ld	r1,PACA_DBG_STACK(r13);					    \
69	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
70#define SPRN_DBG_SRR0	SPRN_DSRR0
71#define SPRN_DBG_SRR1	SPRN_DSRR1
72
73#define MC_SET_KSTACK						            \
74	ld	r1,PACA_MC_STACK(r13);					    \
75	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
76#define SPRN_MC_SRR0	SPRN_MCSRR0
77#define SPRN_MC_SRR1	SPRN_MCSRR1
78
79#define NORMAL_EXCEPTION_PROLOG(n, addition)				    \
80	EXCEPTION_PROLOG(n, GEN, addition##_GEN)
81
82#define CRIT_EXCEPTION_PROLOG(n, addition)				    \
83	EXCEPTION_PROLOG(n, CRIT, addition##_CRIT)
84
85#define DBG_EXCEPTION_PROLOG(n, addition)				    \
86	EXCEPTION_PROLOG(n, DBG, addition##_DBG)
87
88#define MC_EXCEPTION_PROLOG(n, addition)				    \
89	EXCEPTION_PROLOG(n, MC, addition##_MC)
90
91
92/* Variants of the "addition" argument for the prolog
93 */
94#define PROLOG_ADDITION_NONE_GEN
95#define PROLOG_ADDITION_NONE_CRIT
96#define PROLOG_ADDITION_NONE_DBG
97#define PROLOG_ADDITION_NONE_MC
98
99#define PROLOG_ADDITION_MASKABLE_GEN					    \
100	lbz	r11,PACASOFTIRQEN(r13); /* are irqs soft-disabled ? */	    \
101	cmpwi	cr0,r11,0;		/* yes -> go out of line */	    \
102	beq	masked_interrupt_book3e;
103
104#define PROLOG_ADDITION_2REGS_GEN					    \
105	std	r14,PACA_EXGEN+EX_R14(r13);				    \
106	std	r15,PACA_EXGEN+EX_R15(r13)
107
108#define PROLOG_ADDITION_1REG_GEN					    \
109	std	r14,PACA_EXGEN+EX_R14(r13);
110
111#define PROLOG_ADDITION_2REGS_CRIT					    \
112	std	r14,PACA_EXCRIT+EX_R14(r13);				    \
113	std	r15,PACA_EXCRIT+EX_R15(r13)
114
115#define PROLOG_ADDITION_2REGS_DBG					    \
116	std	r14,PACA_EXDBG+EX_R14(r13);				    \
117	std	r15,PACA_EXDBG+EX_R15(r13)
118
119#define PROLOG_ADDITION_2REGS_MC					    \
120	std	r14,PACA_EXMC+EX_R14(r13);				    \
121	std	r15,PACA_EXMC+EX_R15(r13)
122
123/* Core exception code for all exceptions except TLB misses.
124 * XXX: Needs to make SPRN_SPRG_GEN depend on exception type
125 */
126#define EXCEPTION_COMMON(n, excf, ints)					    \
127	std	r0,GPR0(r1);		/* save r0 in stackframe */	    \
128	std	r2,GPR2(r1);		/* save r2 in stackframe */	    \
129	SAVE_4GPRS(3, r1);		/* save r3 - r6 in stackframe */    \
130	SAVE_2GPRS(7, r1);		/* save r7, r8 in stackframe */	    \
131	std	r9,GPR9(r1);		/* save r9 in stackframe */	    \
132	std	r10,_NIP(r1);		/* save SRR0 to stackframe */	    \
133	std	r11,_MSR(r1);		/* save SRR1 to stackframe */	    \
134	ACCOUNT_CPU_USER_ENTRY(r10,r11);/* accounting (uses cr0+eq) */	    \
135	ld	r3,excf+EX_R10(r13);	/* get back r10 */		    \
136	ld	r4,excf+EX_R11(r13);	/* get back r11 */		    \
137	mfspr	r5,SPRN_SPRG_GEN_SCRATCH;/* get back r13 */		    \
138	std	r12,GPR12(r1);		/* save r12 in stackframe */	    \
139	ld	r2,PACATOC(r13);	/* get kernel TOC into r2 */	    \
140	mflr	r6;			/* save LR in stackframe */	    \
141	mfctr	r7;			/* save CTR in stackframe */	    \
142	mfspr	r8,SPRN_XER;		/* save XER in stackframe */	    \
143	ld	r9,excf+EX_R1(r13);	/* load orig r1 back from PACA */   \
144	lwz	r10,excf+EX_CR(r13);	/* load orig CR back from PACA	*/  \
145	lbz	r11,PACASOFTIRQEN(r13);	/* get current IRQ softe */	    \
146	ld	r12,exception_marker@toc(r2);				    \
147	li	r0,0;							    \
148	std	r3,GPR10(r1);		/* save r10 to stackframe */	    \
149	std	r4,GPR11(r1);		/* save r11 to stackframe */	    \
150	std	r5,GPR13(r1);		/* save it to stackframe */	    \
151	std	r6,_LINK(r1);						    \
152	std	r7,_CTR(r1);						    \
153	std	r8,_XER(r1);						    \
154	li	r3,(n)+1;		/* indicate partial regs in trap */ \
155	std	r9,0(r1);		/* store stack frame back link */   \
156	std	r10,_CCR(r1);		/* store orig CR in stackframe */   \
157	std	r9,GPR1(r1);		/* store stack frame back link */   \
158	std	r11,SOFTE(r1);		/* and save it to stackframe */     \
159	std	r12,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame */	    \
160	std	r3,_TRAP(r1);		/* set trap number		*/  \
161	std	r0,RESULT(r1);		/* clear regs->result */	    \
162	ints;
163
164/* Variants for the "ints" argument */
165#define INTS_KEEP
166#define INTS_DISABLE_SOFT						    \
167	stb	r0,PACASOFTIRQEN(r13);	/* mark interrupts soft-disabled */ \
168	TRACE_DISABLE_INTS;
169#define INTS_DISABLE_HARD						    \
170	stb	r0,PACAHARDIRQEN(r13); /* and hard disabled */
171#define INTS_DISABLE_ALL						    \
172	INTS_DISABLE_SOFT						    \
173	INTS_DISABLE_HARD
174
175/* This is called by exceptions that used INTS_KEEP (that is did not clear
176 * neither soft nor hard IRQ indicators in the PACA. This will restore MSR:EE
177 * to it's previous value
178 *
179 * XXX In the long run, we may want to open-code it in order to separate the
180 *     load from the wrtee, thus limiting the latency caused by the dependency
181 *     but at this point, I'll favor code clarity until we have a near to final
182 *     implementation
183 */
184#define INTS_RESTORE_HARD						    \
185	ld	r11,_MSR(r1);						    \
186	wrtee	r11;
187
188/* XXX FIXME: Restore r14/r15 when necessary */
189#define BAD_STACK_TRAMPOLINE(n)						    \
190exc_##n##_bad_stack:							    \
191	li	r1,(n);			/* get exception number */	    \
192	sth	r1,PACA_TRAP_SAVE(r13);	/* store trap */		    \
193	b	bad_stack_book3e;	/* bad stack error */
194
195#define	EXCEPTION_STUB(loc, label)					\
196	. = interrupt_base_book3e + loc;				\
197	nop;	/* To make debug interrupts happy */			\
198	b	exc_##label##_book3e;
199
200#define ACK_NONE(r)
201#define ACK_DEC(r)							\
202	lis	r,TSR_DIS@h;						\
203	mtspr	SPRN_TSR,r
204#define ACK_FIT(r)							\
205	lis	r,TSR_FIS@h;						\
206	mtspr	SPRN_TSR,r
207
208#define MASKABLE_EXCEPTION(trapnum, label, hdlr, ack)			\
209	START_EXCEPTION(label);						\
210	NORMAL_EXCEPTION_PROLOG(trapnum, PROLOG_ADDITION_MASKABLE)	\
211	EXCEPTION_COMMON(trapnum, PACA_EXGEN, INTS_DISABLE_ALL)		\
212	ack(r8);							\
213	addi	r3,r1,STACK_FRAME_OVERHEAD;				\
214	bl	hdlr;							\
215	b	.ret_from_except_lite;
216
217/* This value is used to mark exception frames on the stack. */
218	.section	".toc","aw"
219exception_marker:
220	.tc	ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER
221
222
223/*
224 * And here we have the exception vectors !
225 */
226
227	.text
228	.balign	0x1000
229	.globl interrupt_base_book3e
230interrupt_base_book3e:					/* fake trap */
231	/* Note: If real debug exceptions are supported by the HW, the vector
232	 * below will have to be patched up to point to an appropriate handler
233	 */
234	EXCEPTION_STUB(0x000, machine_check)		/* 0x0200 */
235	EXCEPTION_STUB(0x020, critical_input)		/* 0x0580 */
236	EXCEPTION_STUB(0x040, debug_crit)		/* 0x0d00 */
237	EXCEPTION_STUB(0x060, data_storage)		/* 0x0300 */
238	EXCEPTION_STUB(0x080, instruction_storage)	/* 0x0400 */
239	EXCEPTION_STUB(0x0a0, external_input)		/* 0x0500 */
240	EXCEPTION_STUB(0x0c0, alignment)		/* 0x0600 */
241	EXCEPTION_STUB(0x0e0, program)			/* 0x0700 */
242	EXCEPTION_STUB(0x100, fp_unavailable)		/* 0x0800 */
243	EXCEPTION_STUB(0x120, system_call)		/* 0x0c00 */
244	EXCEPTION_STUB(0x140, ap_unavailable)		/* 0x0f20 */
245	EXCEPTION_STUB(0x160, decrementer)		/* 0x0900 */
246	EXCEPTION_STUB(0x180, fixed_interval)		/* 0x0980 */
247	EXCEPTION_STUB(0x1a0, watchdog)			/* 0x09f0 */
248	EXCEPTION_STUB(0x1c0, data_tlb_miss)
249	EXCEPTION_STUB(0x1e0, instruction_tlb_miss)
250
251#if 0
252	EXCEPTION_STUB(0x280, processor_doorbell)
253	EXCEPTION_STUB(0x220, processor_doorbell_crit)
254#endif
255	.globl interrupt_end_book3e
256interrupt_end_book3e:
257
258/* Critical Input Interrupt */
259	START_EXCEPTION(critical_input);
260	CRIT_EXCEPTION_PROLOG(0x100, PROLOG_ADDITION_NONE)
261//	EXCEPTION_COMMON(0x100, PACA_EXCRIT, INTS_DISABLE_ALL)
262//	bl	special_reg_save_crit
263//	addi	r3,r1,STACK_FRAME_OVERHEAD
264//	bl	.critical_exception
265//	b	ret_from_crit_except
266	b	.
267
268/* Machine Check Interrupt */
269	START_EXCEPTION(machine_check);
270	CRIT_EXCEPTION_PROLOG(0x200, PROLOG_ADDITION_NONE)
271//	EXCEPTION_COMMON(0x200, PACA_EXMC, INTS_DISABLE_ALL)
272//	bl	special_reg_save_mc
273//	addi	r3,r1,STACK_FRAME_OVERHEAD
274//	bl	.machine_check_exception
275//	b	ret_from_mc_except
276	b	.
277
278/* Data Storage Interrupt */
279	START_EXCEPTION(data_storage)
280	NORMAL_EXCEPTION_PROLOG(0x300, PROLOG_ADDITION_2REGS)
281	mfspr	r14,SPRN_DEAR
282	mfspr	r15,SPRN_ESR
283	EXCEPTION_COMMON(0x300, PACA_EXGEN, INTS_KEEP)
284	b	storage_fault_common
285
286/* Instruction Storage Interrupt */
287	START_EXCEPTION(instruction_storage);
288	NORMAL_EXCEPTION_PROLOG(0x400, PROLOG_ADDITION_2REGS)
289	li	r15,0
290	mr	r14,r10
291	EXCEPTION_COMMON(0x400, PACA_EXGEN, INTS_KEEP)
292	b	storage_fault_common
293
294/* External Input Interrupt */
295	MASKABLE_EXCEPTION(0x500, external_input, .do_IRQ, ACK_NONE)
296
297/* Alignment */
298	START_EXCEPTION(alignment);
299	NORMAL_EXCEPTION_PROLOG(0x600, PROLOG_ADDITION_2REGS)
300	mfspr	r14,SPRN_DEAR
301	mfspr	r15,SPRN_ESR
302	EXCEPTION_COMMON(0x600, PACA_EXGEN, INTS_KEEP)
303	b	alignment_more	/* no room, go out of line */
304
305/* Program Interrupt */
306	START_EXCEPTION(program);
307	NORMAL_EXCEPTION_PROLOG(0x700, PROLOG_ADDITION_1REG)
308	mfspr	r14,SPRN_ESR
309	EXCEPTION_COMMON(0x700, PACA_EXGEN, INTS_DISABLE_SOFT)
310	std	r14,_DSISR(r1)
311	addi	r3,r1,STACK_FRAME_OVERHEAD
312	ld	r14,PACA_EXGEN+EX_R14(r13)
313	bl	.save_nvgprs
314	INTS_RESTORE_HARD
315	bl	.program_check_exception
316	b	.ret_from_except
317
318/* Floating Point Unavailable Interrupt */
319	START_EXCEPTION(fp_unavailable);
320	NORMAL_EXCEPTION_PROLOG(0x800, PROLOG_ADDITION_NONE)
321	/* we can probably do a shorter exception entry for that one... */
322	EXCEPTION_COMMON(0x800, PACA_EXGEN, INTS_KEEP)
323	bne	1f			/* if from user, just load it up */
324	bl	.save_nvgprs
325	addi	r3,r1,STACK_FRAME_OVERHEAD
326	INTS_RESTORE_HARD
327	bl	.kernel_fp_unavailable_exception
328	BUG_OPCODE
3291:	ld	r12,_MSR(r1)
330	bl	.load_up_fpu
331	b	fast_exception_return
332
333/* Decrementer Interrupt */
334	MASKABLE_EXCEPTION(0x900, decrementer, .timer_interrupt, ACK_DEC)
335
336/* Fixed Interval Timer Interrupt */
337	MASKABLE_EXCEPTION(0x980, fixed_interval, .unknown_exception, ACK_FIT)
338
339/* Watchdog Timer Interrupt */
340	START_EXCEPTION(watchdog);
341	CRIT_EXCEPTION_PROLOG(0x9f0, PROLOG_ADDITION_NONE)
342//	EXCEPTION_COMMON(0x9f0, PACA_EXCRIT, INTS_DISABLE_ALL)
343//	bl	special_reg_save_crit
344//	addi	r3,r1,STACK_FRAME_OVERHEAD
345//	bl	.unknown_exception
346//	b	ret_from_crit_except
347	b	.
348
349/* System Call Interrupt */
350	START_EXCEPTION(system_call)
351	mr	r9,r13			/* keep a copy of userland r13 */
352	mfspr	r11,SPRN_SRR0		/* get return address */
353	mfspr	r12,SPRN_SRR1		/* get previous MSR */
354	mfspr	r13,SPRN_SPRG_PACA	/* get our PACA */
355	b	system_call_common
356
357/* Auxillary Processor Unavailable Interrupt */
358	START_EXCEPTION(ap_unavailable);
359	NORMAL_EXCEPTION_PROLOG(0xf20, PROLOG_ADDITION_NONE)
360	EXCEPTION_COMMON(0xf20, PACA_EXGEN, INTS_KEEP)
361	addi	r3,r1,STACK_FRAME_OVERHEAD
362	bl	.save_nvgprs
363	INTS_RESTORE_HARD
364	bl	.unknown_exception
365	b	.ret_from_except
366
367/* Debug exception as a critical interrupt*/
368	START_EXCEPTION(debug_crit);
369	CRIT_EXCEPTION_PROLOG(0xd00, PROLOG_ADDITION_2REGS)
370
371	/*
372	 * If there is a single step or branch-taken exception in an
373	 * exception entry sequence, it was probably meant to apply to
374	 * the code where the exception occurred (since exception entry
375	 * doesn't turn off DE automatically).  We simulate the effect
376	 * of turning off DE on entry to an exception handler by turning
377	 * off DE in the CSRR1 value and clearing the debug status.
378	 */
379
380	mfspr	r14,SPRN_DBSR		/* check single-step/branch taken */
381	andis.	r15,r14,DBSR_IC@h
382	beq+	1f
383
384	LOAD_REG_IMMEDIATE(r14,interrupt_base_book3e)
385	LOAD_REG_IMMEDIATE(r15,interrupt_end_book3e)
386	cmpld	cr0,r10,r14
387	cmpld	cr1,r10,r15
388	blt+	cr0,1f
389	bge+	cr1,1f
390
391	/* here it looks like we got an inappropriate debug exception. */
392	lis	r14,DBSR_IC@h		/* clear the IC event */
393	rlwinm	r11,r11,0,~MSR_DE	/* clear DE in the CSRR1 value */
394	mtspr	SPRN_DBSR,r14
395	mtspr	SPRN_CSRR1,r11
396	lwz	r10,PACA_EXCRIT+EX_CR(r13)	/* restore registers */
397	ld	r1,PACA_EXCRIT+EX_R1(r13)
398	ld	r14,PACA_EXCRIT+EX_R14(r13)
399	ld	r15,PACA_EXCRIT+EX_R15(r13)
400	mtcr	r10
401	ld	r10,PACA_EXCRIT+EX_R10(r13)	/* restore registers */
402	ld	r11,PACA_EXCRIT+EX_R11(r13)
403	mfspr	r13,SPRN_SPRG_CRIT_SCRATCH
404	rfci
405
406	/* Normal debug exception */
407	/* XXX We only handle coming from userspace for now since we can't
408	 *     quite save properly an interrupted kernel state yet
409	 */
4101:	andi.	r14,r11,MSR_PR;		/* check for userspace again */
411	beq	kernel_dbg_exc;		/* if from kernel mode */
412
413	/* Now we mash up things to make it look like we are coming on a
414	 * normal exception
415	 */
416	mfspr	r15,SPRN_SPRG_CRIT_SCRATCH
417	mtspr	SPRN_SPRG_GEN_SCRATCH,r15
418	mfspr	r14,SPRN_DBSR
419	EXCEPTION_COMMON(0xd00, PACA_EXCRIT, INTS_DISABLE_ALL)
420	std	r14,_DSISR(r1)
421	addi	r3,r1,STACK_FRAME_OVERHEAD
422	mr	r4,r14
423	ld	r14,PACA_EXCRIT+EX_R14(r13)
424	ld	r15,PACA_EXCRIT+EX_R15(r13)
425	bl	.save_nvgprs
426	bl	.DebugException
427	b	.ret_from_except
428
429kernel_dbg_exc:
430	b	.	/* NYI */
431
432
433/*
434 * An interrupt came in while soft-disabled; clear EE in SRR1,
435 * clear paca->hard_enabled and return.
436 */
437masked_interrupt_book3e:
438	mtcr	r10
439	stb	r11,PACAHARDIRQEN(r13)
440	mfspr	r10,SPRN_SRR1
441	rldicl	r11,r10,48,1		/* clear MSR_EE */
442	rotldi	r10,r11,16
443	mtspr	SPRN_SRR1,r10
444	ld	r10,PACA_EXGEN+EX_R10(r13);	/* restore registers */
445	ld	r11,PACA_EXGEN+EX_R11(r13);
446	mfspr	r13,SPRN_SPRG_GEN_SCRATCH;
447	rfi
448	b	.
449
450/*
451 * This is called from 0x300 and 0x400 handlers after the prologs with
452 * r14 and r15 containing the fault address and error code, with the
453 * original values stashed away in the PACA
454 */
455storage_fault_common:
456	std	r14,_DAR(r1)
457	std	r15,_DSISR(r1)
458	addi	r3,r1,STACK_FRAME_OVERHEAD
459	mr	r4,r14
460	mr	r5,r15
461	ld	r14,PACA_EXGEN+EX_R14(r13)
462	ld	r15,PACA_EXGEN+EX_R15(r13)
463	INTS_RESTORE_HARD
464	bl	.do_page_fault
465	cmpdi	r3,0
466	bne-	1f
467	b	.ret_from_except_lite
4681:	bl	.save_nvgprs
469	mr	r5,r3
470	addi	r3,r1,STACK_FRAME_OVERHEAD
471	ld	r4,_DAR(r1)
472	bl	.bad_page_fault
473	b	.ret_from_except
474
475/*
476 * Alignment exception doesn't fit entirely in the 0x100 bytes so it
477 * continues here.
478 */
479alignment_more:
480	std	r14,_DAR(r1)
481	std	r15,_DSISR(r1)
482	addi	r3,r1,STACK_FRAME_OVERHEAD
483	ld	r14,PACA_EXGEN+EX_R14(r13)
484	ld	r15,PACA_EXGEN+EX_R15(r13)
485	bl	.save_nvgprs
486	INTS_RESTORE_HARD
487	bl	.alignment_exception
488	b	.ret_from_except
489
490/*
491 * We branch here from entry_64.S for the last stage of the exception
492 * return code path. MSR:EE is expected to be off at that point
493 */
494_GLOBAL(exception_return_book3e)
495	b	1f
496
497/* This is the return from load_up_fpu fast path which could do with
498 * less GPR restores in fact, but for now we have a single return path
499 */
500	.globl fast_exception_return
501fast_exception_return:
502	wrteei	0
5031:	mr	r0,r13
504	ld	r10,_MSR(r1)
505	REST_4GPRS(2, r1)
506	andi.	r6,r10,MSR_PR
507	REST_2GPRS(6, r1)
508	beq	1f
509	ACCOUNT_CPU_USER_EXIT(r10, r11)
510	ld	r0,GPR13(r1)
511
5121:	stdcx.	r0,0,r1		/* to clear the reservation */
513
514	ld	r8,_CCR(r1)
515	ld	r9,_LINK(r1)
516	ld	r10,_CTR(r1)
517	ld	r11,_XER(r1)
518	mtcr	r8
519	mtlr	r9
520	mtctr	r10
521	mtxer	r11
522	REST_2GPRS(8, r1)
523	ld	r10,GPR10(r1)
524	ld	r11,GPR11(r1)
525	ld	r12,GPR12(r1)
526	mtspr	SPRN_SPRG_GEN_SCRATCH,r0
527
528	std	r10,PACA_EXGEN+EX_R10(r13);
529	std	r11,PACA_EXGEN+EX_R11(r13);
530	ld	r10,_NIP(r1)
531	ld	r11,_MSR(r1)
532	ld	r0,GPR0(r1)
533	ld	r1,GPR1(r1)
534	mtspr	SPRN_SRR0,r10
535	mtspr	SPRN_SRR1,r11
536	ld	r10,PACA_EXGEN+EX_R10(r13)
537	ld	r11,PACA_EXGEN+EX_R11(r13)
538	mfspr	r13,SPRN_SPRG_GEN_SCRATCH
539	rfi
540
541/*
542 * Trampolines used when spotting a bad kernel stack pointer in
543 * the exception entry code.
544 *
545 * TODO: move some bits like SRR0 read to trampoline, pass PACA
546 * index around, etc... to handle crit & mcheck
547 */
548BAD_STACK_TRAMPOLINE(0x000)
549BAD_STACK_TRAMPOLINE(0x100)
550BAD_STACK_TRAMPOLINE(0x200)
551BAD_STACK_TRAMPOLINE(0x300)
552BAD_STACK_TRAMPOLINE(0x400)
553BAD_STACK_TRAMPOLINE(0x500)
554BAD_STACK_TRAMPOLINE(0x600)
555BAD_STACK_TRAMPOLINE(0x700)
556BAD_STACK_TRAMPOLINE(0x800)
557BAD_STACK_TRAMPOLINE(0x900)
558BAD_STACK_TRAMPOLINE(0x980)
559BAD_STACK_TRAMPOLINE(0x9f0)
560BAD_STACK_TRAMPOLINE(0xa00)
561BAD_STACK_TRAMPOLINE(0xb00)
562BAD_STACK_TRAMPOLINE(0xc00)
563BAD_STACK_TRAMPOLINE(0xd00)
564BAD_STACK_TRAMPOLINE(0xe00)
565BAD_STACK_TRAMPOLINE(0xf00)
566BAD_STACK_TRAMPOLINE(0xf20)
567
568	.globl	bad_stack_book3e
569bad_stack_book3e:
570	/* XXX: Needs to make SPRN_SPRG_GEN depend on exception type */
571	mfspr	r10,SPRN_SRR0;		  /* read SRR0 before touching stack */
572	ld	r1,PACAEMERGSP(r13)
573	subi	r1,r1,64+INT_FRAME_SIZE
574	std	r10,_NIP(r1)
575	std	r11,_MSR(r1)
576	ld	r10,PACA_EXGEN+EX_R1(r13) /* FIXME for crit & mcheck */
577	lwz	r11,PACA_EXGEN+EX_CR(r13) /* FIXME for crit & mcheck */
578	std	r10,GPR1(r1)
579	std	r11,_CCR(r1)
580	mfspr	r10,SPRN_DEAR
581	mfspr	r11,SPRN_ESR
582	std	r10,_DAR(r1)
583	std	r11,_DSISR(r1)
584	std	r0,GPR0(r1);		/* save r0 in stackframe */	    \
585	std	r2,GPR2(r1);		/* save r2 in stackframe */	    \
586	SAVE_4GPRS(3, r1);		/* save r3 - r6 in stackframe */    \
587	SAVE_2GPRS(7, r1);		/* save r7, r8 in stackframe */	    \
588	std	r9,GPR9(r1);		/* save r9 in stackframe */	    \
589	ld	r3,PACA_EXGEN+EX_R10(r13);/* get back r10 */		    \
590	ld	r4,PACA_EXGEN+EX_R11(r13);/* get back r11 */		    \
591	mfspr	r5,SPRN_SPRG_GEN_SCRATCH;/* get back r13 XXX can be wrong */ \
592	std	r3,GPR10(r1);		/* save r10 to stackframe */	    \
593	std	r4,GPR11(r1);		/* save r11 to stackframe */	    \
594	std	r12,GPR12(r1);		/* save r12 in stackframe */	    \
595	std	r5,GPR13(r1);		/* save it to stackframe */	    \
596	mflr	r10
597	mfctr	r11
598	mfxer	r12
599	std	r10,_LINK(r1)
600	std	r11,_CTR(r1)
601	std	r12,_XER(r1)
602	SAVE_10GPRS(14,r1)
603	SAVE_8GPRS(24,r1)
604	lhz	r12,PACA_TRAP_SAVE(r13)
605	std	r12,_TRAP(r1)
606	addi	r11,r1,INT_FRAME_SIZE
607	std	r11,0(r1)
608	li	r12,0
609	std	r12,0(r11)
610	ld	r2,PACATOC(r13)
6111:	addi	r3,r1,STACK_FRAME_OVERHEAD
612	bl	.kernel_bad_stack
613	b	1b
614
615/*
616 * Setup the initial TLB for a core. This current implementation
617 * assume that whatever we are running off will not conflict with
618 * the new mapping at PAGE_OFFSET.
619 */
620_GLOBAL(initial_tlb_book3e)
621
622	/* Look for the first TLB with IPROT set */
623	mfspr	r4,SPRN_TLB0CFG
624	andi.	r3,r4,TLBnCFG_IPROT
625	lis	r3,MAS0_TLBSEL(0)@h
626	bne	found_iprot
627
628	mfspr	r4,SPRN_TLB1CFG
629	andi.	r3,r4,TLBnCFG_IPROT
630	lis	r3,MAS0_TLBSEL(1)@h
631	bne	found_iprot
632
633	mfspr	r4,SPRN_TLB2CFG
634	andi.	r3,r4,TLBnCFG_IPROT
635	lis	r3,MAS0_TLBSEL(2)@h
636	bne	found_iprot
637
638	lis	r3,MAS0_TLBSEL(3)@h
639	mfspr	r4,SPRN_TLB3CFG
640	/* fall through */
641
642found_iprot:
643	andi.	r5,r4,TLBnCFG_HES
644	bne	have_hes
645
646	mflr	r8				/* save LR */
647/* 1. Find the index of the entry we're executing in
648 *
649 * r3 = MAS0_TLBSEL (for the iprot array)
650 * r4 = SPRN_TLBnCFG
651 */
652	bl	invstr				/* Find our address */
653invstr:	mflr	r6				/* Make it accessible */
654	mfmsr	r7
655	rlwinm	r5,r7,27,31,31			/* extract MSR[IS] */
656	mfspr	r7,SPRN_PID
657	slwi	r7,r7,16
658	or	r7,r7,r5
659	mtspr	SPRN_MAS6,r7
660	tlbsx	0,r6				/* search MSR[IS], SPID=PID */
661
662	mfspr	r3,SPRN_MAS0
663	rlwinm	r5,r3,16,20,31			/* Extract MAS0(Entry) */
664
665	mfspr	r7,SPRN_MAS1			/* Insure IPROT set */
666	oris	r7,r7,MAS1_IPROT@h
667	mtspr	SPRN_MAS1,r7
668	tlbwe
669
670/* 2. Invalidate all entries except the entry we're executing in
671 *
672 * r3 = MAS0 w/TLBSEL & ESEL for the entry we are running in
673 * r4 = SPRN_TLBnCFG
674 * r5 = ESEL of entry we are running in
675 */
676	andi.	r4,r4,TLBnCFG_N_ENTRY		/* Extract # entries */
677	li	r6,0				/* Set Entry counter to 0 */
6781:	mr	r7,r3				/* Set MAS0(TLBSEL) */
679	rlwimi	r7,r6,16,4,15			/* Setup MAS0 = TLBSEL | ESEL(r6) */
680	mtspr	SPRN_MAS0,r7
681	tlbre
682	mfspr	r7,SPRN_MAS1
683	rlwinm	r7,r7,0,2,31			/* Clear MAS1 Valid and IPROT */
684	cmpw	r5,r6
685	beq	skpinv				/* Dont update the current execution TLB */
686	mtspr	SPRN_MAS1,r7
687	tlbwe
688	isync
689skpinv:	addi	r6,r6,1				/* Increment */
690	cmpw	r6,r4				/* Are we done? */
691	bne	1b				/* If not, repeat */
692
693	/* Invalidate all TLBs */
694	PPC_TLBILX_ALL(0,0)
695	sync
696	isync
697
698/* 3. Setup a temp mapping and jump to it
699 *
700 * r3 = MAS0 w/TLBSEL & ESEL for the entry we are running in
701 * r5 = ESEL of entry we are running in
702 */
703	andi.	r7,r5,0x1	/* Find an entry not used and is non-zero */
704	addi	r7,r7,0x1
705	mr	r4,r3		/* Set MAS0(TLBSEL) = 1 */
706	mtspr	SPRN_MAS0,r4
707	tlbre
708
709	rlwimi	r4,r7,16,4,15	/* Setup MAS0 = TLBSEL | ESEL(r7) */
710	mtspr	SPRN_MAS0,r4
711
712	mfspr	r7,SPRN_MAS1
713	xori	r6,r7,MAS1_TS		/* Setup TMP mapping in the other Address space */
714	mtspr	SPRN_MAS1,r6
715
716	tlbwe
717
718	mfmsr	r6
719	xori	r6,r6,MSR_IS
720	mtspr	SPRN_SRR1,r6
721	bl	1f		/* Find our address */
7221:	mflr	r6
723	addi	r6,r6,(2f - 1b)
724	mtspr	SPRN_SRR0,r6
725	rfi
7262:
727
728/* 4. Clear out PIDs & Search info
729 *
730 * r3 = MAS0 w/TLBSEL & ESEL for the entry we started in
731 * r4 = MAS0 w/TLBSEL & ESEL for the temp mapping
732 * r5 = MAS3
733 */
734	li	r6,0
735	mtspr   SPRN_MAS6,r6
736	mtspr	SPRN_PID,r6
737
738/* 5. Invalidate mapping we started in
739 *
740 * r3 = MAS0 w/TLBSEL & ESEL for the entry we started in
741 * r4 = MAS0 w/TLBSEL & ESEL for the temp mapping
742 * r5 = MAS3
743 */
744	mtspr	SPRN_MAS0,r3
745	tlbre
746	mfspr	r6,SPRN_MAS1
747	rlwinm	r6,r6,0,2,0	/* clear IPROT */
748	mtspr	SPRN_MAS1,r6
749	tlbwe
750
751	/* Invalidate TLB1 */
752	PPC_TLBILX_ALL(0,0)
753	sync
754	isync
755
756/* The mapping only needs to be cache-coherent on SMP */
757#ifdef CONFIG_SMP
758#define M_IF_SMP	MAS2_M
759#else
760#define M_IF_SMP	0
761#endif
762
763/* 6. Setup KERNELBASE mapping in TLB[0]
764 *
765 * r3 = MAS0 w/TLBSEL & ESEL for the entry we started in
766 * r4 = MAS0 w/TLBSEL & ESEL for the temp mapping
767 * r5 = MAS3
768 */
769	rlwinm	r3,r3,0,16,3	/* clear ESEL */
770	mtspr	SPRN_MAS0,r3
771	lis	r6,(MAS1_VALID|MAS1_IPROT)@h
772	ori	r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_1GB))@l
773	mtspr	SPRN_MAS1,r6
774
775	LOAD_REG_IMMEDIATE(r6, PAGE_OFFSET | M_IF_SMP)
776	mtspr	SPRN_MAS2,r6
777
778	rlwinm	r5,r5,0,0,25
779	ori	r5,r5,MAS3_SR | MAS3_SW | MAS3_SX
780	mtspr	SPRN_MAS3,r5
781	li	r5,-1
782	rlwinm	r5,r5,0,0,25
783
784	tlbwe
785
786/* 7. Jump to KERNELBASE mapping
787 *
788 * r4 = MAS0 w/TLBSEL & ESEL for the temp mapping
789 */
790	/* Now we branch the new virtual address mapped by this entry */
791	LOAD_REG_IMMEDIATE(r6,2f)
792	lis	r7,MSR_KERNEL@h
793	ori	r7,r7,MSR_KERNEL@l
794	mtspr	SPRN_SRR0,r6
795	mtspr	SPRN_SRR1,r7
796	rfi				/* start execution out of TLB1[0] entry */
7972:
798
799/* 8. Clear out the temp mapping
800 *
801 * r4 = MAS0 w/TLBSEL & ESEL for the entry we are running in
802 */
803	mtspr	SPRN_MAS0,r4
804	tlbre
805	mfspr	r5,SPRN_MAS1
806	rlwinm	r5,r5,0,2,0	/* clear IPROT */
807	mtspr	SPRN_MAS1,r5
808	tlbwe
809
810	/* Invalidate TLB1 */
811	PPC_TLBILX_ALL(0,0)
812	sync
813	isync
814
815	/* We translate LR and return */
816	tovirt(r8,r8)
817	mtlr	r8
818	blr
819
820have_hes:
821	/* Setup MAS 0,1,2,3 and 7 for tlbwe of a 1G entry that maps the
822	 * kernel linear mapping. We also set MAS8 once for all here though
823	 * that will have to be made dependent on whether we are running under
824	 * a hypervisor I suppose.
825	 */
826	ori	r3,r3,MAS0_HES | MAS0_WQ_ALLWAYS
827	mtspr	SPRN_MAS0,r3
828	lis	r3,(MAS1_VALID | MAS1_IPROT)@h
829	ori	r3,r3,BOOK3E_PAGESZ_1GB << MAS1_TSIZE_SHIFT
830	mtspr	SPRN_MAS1,r3
831	LOAD_REG_IMMEDIATE(r3, PAGE_OFFSET | MAS2_M)
832	mtspr	SPRN_MAS2,r3
833	li	r3,MAS3_SR | MAS3_SW | MAS3_SX
834	mtspr	SPRN_MAS7_MAS3,r3
835	li	r3,0
836	mtspr	SPRN_MAS8,r3
837
838	/* Write the TLB entry */
839	tlbwe
840
841	/* Now we branch the new virtual address mapped by this entry */
842	LOAD_REG_IMMEDIATE(r3,1f)
843	mtctr	r3
844	bctr
845
8461:	/* We are now running at PAGE_OFFSET, clean the TLB of everything
847	 * else (XXX we should scan for bolted crap from the firmware too)
848	 */
849	PPC_TLBILX(0,0,0)
850	sync
851	isync
852
853	/* We translate LR and return */
854	mflr	r3
855	tovirt(r3,r3)
856	mtlr	r3
857	blr
858
859/*
860 * Main entry (boot CPU, thread 0)
861 *
862 * We enter here from head_64.S, possibly after the prom_init trampoline
863 * with r3 and r4 already saved to r31 and 30 respectively and in 64 bits
864 * mode. Anything else is as it was left by the bootloader
865 *
866 * Initial requirements of this port:
867 *
868 * - Kernel loaded at 0 physical
869 * - A good lump of memory mapped 0:0 by UTLB entry 0
870 * - MSR:IS & MSR:DS set to 0
871 *
872 * Note that some of the above requirements will be relaxed in the future
873 * as the kernel becomes smarter at dealing with different initial conditions
874 * but for now you have to be careful
875 */
876_GLOBAL(start_initialization_book3e)
877	mflr	r28
878
879	/* First, we need to setup some initial TLBs to map the kernel
880	 * text, data and bss at PAGE_OFFSET. We don't have a real mode
881	 * and always use AS 0, so we just set it up to match our link
882	 * address and never use 0 based addresses.
883	 */
884	bl	.initial_tlb_book3e
885
886	/* Init global core bits */
887	bl	.init_core_book3e
888
889	/* Init per-thread bits */
890	bl	.init_thread_book3e
891
892	/* Return to common init code */
893	tovirt(r28,r28)
894	mtlr	r28
895	blr
896
897
898/*
899 * Secondary core/processor entry
900 *
901 * This is entered for thread 0 of a secondary core, all other threads
902 * are expected to be stopped. It's similar to start_initialization_book3e
903 * except that it's generally entered from the holding loop in head_64.S
904 * after CPUs have been gathered by Open Firmware.
905 *
906 * We assume we are in 32 bits mode running with whatever TLB entry was
907 * set for us by the firmware or POR engine.
908 */
909_GLOBAL(book3e_secondary_core_init_tlb_set)
910	li	r4,1
911	b	.generic_secondary_smp_init
912
913_GLOBAL(book3e_secondary_core_init)
914	mflr	r28
915
916	/* Do we need to setup initial TLB entry ? */
917	cmplwi	r4,0
918	bne	2f
919
920	/* Setup TLB for this core */
921	bl	.initial_tlb_book3e
922
923	/* We can return from the above running at a different
924	 * address, so recalculate r2 (TOC)
925	 */
926	bl	.relative_toc
927
928	/* Init global core bits */
9292:	bl	.init_core_book3e
930
931	/* Init per-thread bits */
9323:	bl	.init_thread_book3e
933
934	/* Return to common init code at proper virtual address.
935	 *
936	 * Due to various previous assumptions, we know we entered this
937	 * function at either the final PAGE_OFFSET mapping or using a
938	 * 1:1 mapping at 0, so we don't bother doing a complicated check
939	 * here, we just ensure the return address has the right top bits.
940	 *
941	 * Note that if we ever want to be smarter about where we can be
942	 * started from, we have to be careful that by the time we reach
943	 * the code below we may already be running at a different location
944	 * than the one we were called from since initial_tlb_book3e can
945	 * have moved us already.
946	 */
947	cmpdi	cr0,r28,0
948	blt	1f
949	lis	r3,PAGE_OFFSET@highest
950	sldi	r3,r3,32
951	or	r28,r28,r3
9521:	mtlr	r28
953	blr
954
955_GLOBAL(book3e_secondary_thread_init)
956	mflr	r28
957	b	3b
958
959_STATIC(init_core_book3e)
960	/* Establish the interrupt vector base */
961	LOAD_REG_IMMEDIATE(r3, interrupt_base_book3e)
962	mtspr	SPRN_IVPR,r3
963	sync
964	blr
965
966_STATIC(init_thread_book3e)
967	lis	r3,(SPRN_EPCR_ICM | SPRN_EPCR_GICM)@h
968	mtspr	SPRN_EPCR,r3
969
970	/* Make sure interrupts are off */
971	wrteei	0
972
973	/* disable all timers and clear out status */
974	li	r3,0
975	mtspr	SPRN_TCR,r3
976	mfspr	r3,SPRN_TSR
977	mtspr	SPRN_TSR,r3
978
979	blr
980
981_GLOBAL(__setup_base_ivors)
982	SET_IVOR(0, 0x020) /* Critical Input */
983	SET_IVOR(1, 0x000) /* Machine Check */
984	SET_IVOR(2, 0x060) /* Data Storage */
985	SET_IVOR(3, 0x080) /* Instruction Storage */
986	SET_IVOR(4, 0x0a0) /* External Input */
987	SET_IVOR(5, 0x0c0) /* Alignment */
988	SET_IVOR(6, 0x0e0) /* Program */
989	SET_IVOR(7, 0x100) /* FP Unavailable */
990	SET_IVOR(8, 0x120) /* System Call */
991	SET_IVOR(9, 0x140) /* Auxiliary Processor Unavailable */
992	SET_IVOR(10, 0x160) /* Decrementer */
993	SET_IVOR(11, 0x180) /* Fixed Interval Timer */
994	SET_IVOR(12, 0x1a0) /* Watchdog Timer */
995	SET_IVOR(13, 0x1c0) /* Data TLB Error */
996	SET_IVOR(14, 0x1e0) /* Instruction TLB Error */
997	SET_IVOR(15, 0x040) /* Debug */
998
999	sync
1000
1001	blr
1002