1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __HEAD_BOOKE_H__
#define __HEAD_BOOKE_H__
#include <asm/ptrace.h> /* for STACK_FRAME_REGS_MARKER */
#include <asm/kvm_asm.h>
#include <asm/kvm_booke_hv_asm.h>
#ifdef __ASSEMBLY__
/*
* Macros used for common Book-e exception handling
*/
#define SET_IVOR(vector_number, vector_label) \
li r26,vector_label@l; \
mtspr SPRN_IVOR##vector_number,r26; \
sync
#if (THREAD_SHIFT < 15)
#define ALLOC_STACK_FRAME(reg, val) \
addi reg,reg,val
#else
#define ALLOC_STACK_FRAME(reg, val) \
addis reg,reg,val@ha; \
addi reg,reg,val@l
#endif
/*
* Macro used to get to thread save registers.
* Note that entries 0-3 are used for the prolog code, and the remaining
* entries are available for specific exception use in the event a handler
* requires more than 4 scratch registers.
*/
#define THREAD_NORMSAVE(offset) (THREAD_NORMSAVES + (offset * 4))
#ifdef CONFIG_PPC_FSL_BOOK3E
#define BOOKE_CLEAR_BTB(reg) \
START_BTB_FLUSH_SECTION \
BTB_FLUSH(reg) \
END_BTB_FLUSH_SECTION
#else
#define BOOKE_CLEAR_BTB(reg)
#endif
#define NORMAL_EXCEPTION_PROLOG(trapno, intno) \
mtspr SPRN_SPRG_WSCRATCH0, r10; /* save one register */ \
mfspr r10, SPRN_SPRG_THREAD; \
stw r11, THREAD_NORMSAVE(0)(r10); \
stw r13, THREAD_NORMSAVE(2)(r10); \
mfcr r13; /* save CR in r13 for now */\
mfspr r11, SPRN_SRR1; \
DO_KVM BOOKE_INTERRUPT_##intno SPRN_SRR1; \
andi. r11, r11, MSR_PR; /* check whether user or kernel */\
LOAD_REG_IMMEDIATE(r11, MSR_KERNEL); \
mtmsr r11; \
mr r11, r1; \
beq 1f; \
BOOKE_CLEAR_BTB(r11) \
/* if from user, start at top of this thread's kernel stack */ \
lwz r11, TASK_STACK - THREAD(r10); \
ALLOC_STACK_FRAME(r11, THREAD_SIZE); \
1 : subi r11, r11, INT_FRAME_SIZE; /* Allocate exception frame */ \
stw r13, _CCR(r11); /* save various registers */ \
stw r12,GPR12(r11); \
stw r9,GPR9(r11); \
mfspr r13, SPRN_SPRG_RSCRATCH0; \
stw r13, GPR10(r11); \
lwz r12, THREAD_NORMSAVE(0)(r10); \
stw r12,GPR11(r11); \
lwz r13, THREAD_NORMSAVE(2)(r10); /* restore r13 */ \
mflr r10; \
stw r10,_LINK(r11); \
mfspr r12,SPRN_SRR0; \
stw r1, GPR1(r11); \
mfspr r9,SPRN_SRR1; \
stw r1, 0(r11); \
mr r1, r11; \
rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\
COMMON_EXCEPTION_PROLOG_END trapno
.macro COMMON_EXCEPTION_PROLOG_END trapno
stw r0,GPR0(r1)
lis r10, STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
addi r10, r10, STACK_FRAME_REGS_MARKER@l
stw r10, 8(r1)
li r10, \trapno
stw r10,_TRAP(r1)
SAVE_4GPRS(3, r1)
SAVE_2GPRS(7, r1)
SAVE_NVGPRS(r1)
stw r2,GPR2(r1)
stw r12,_NIP(r1)
stw r9,_MSR(r1)
mfctr r10
mfspr r2,SPRN_SPRG_THREAD
stw r10,_CTR(r1)
tovirt(r2, r2)
mfspr r10,SPRN_XER
addi r2, r2, -THREAD
stw r10,_XER(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
.endm
.macro prepare_transfer_to_handler
#ifdef CONFIG_E500
andi. r12,r9,MSR_PR
bne 777f
bl prepare_transfer_to_handler
777:
#endif
.endm
.macro SYSCALL_ENTRY trapno intno srr1
mfspr r10, SPRN_SPRG_THREAD
#ifdef CONFIG_KVM_BOOKE_HV
BEGIN_FTR_SECTION
mtspr SPRN_SPRG_WSCRATCH0, r10
stw r11, THREAD_NORMSAVE(0)(r10)
stw r13, THREAD_NORMSAVE(2)(r10)
mfcr r13 /* save CR in r13 for now */
mfspr r11, SPRN_SRR1
mtocrf 0x80, r11 /* check MSR[GS] without clobbering reg */
bf 3, 1975f
b kvmppc_handler_\intno\()_\srr1
1975:
mr r12, r13
lwz r13, THREAD_NORMSAVE(2)(r10)
FTR_SECTION_ELSE
mfcr r12
ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
#else
mfcr r12
#endif
mfspr r9, SPRN_SRR1
BOOKE_CLEAR_BTB(r11)
mr r11, r1
lwz r1, TASK_STACK - THREAD(r10)
rlwinm r12,r12,0,4,2 /* Clear SO bit in CR */
ALLOC_STACK_FRAME(r1, THREAD_SIZE - INT_FRAME_SIZE)
stw r12, _CCR(r1)
mfspr r12,SPRN_SRR0
stw r12,_NIP(r1)
b transfer_to_syscall /* jump to handler */
.endm
/* To handle the additional exception priority levels on 40x and Book-E
* processors we allocate a stack per additional priority level.
*
* On 40x critical is the only additional level
* On 44x/e500 we have critical and machine check
*
* Additionally we reserve a SPRG for each priority level so we can free up a
* GPR to use as the base for indirect access to the exception stacks. This
* is necessary since the MMU is always on, for Book-E parts, and the stacks
* are offset from KERNELBASE.
*
* There is some space optimization to be had here if desired. However
* to allow for a common kernel with support for debug exceptions either
* going to critical or their own debug level we aren't currently
* providing configurations that micro-optimize space usage.
*/
#define MC_STACK_BASE mcheckirq_ctx
#define CRIT_STACK_BASE critirq_ctx
/* only on e500mc */
#define DBG_STACK_BASE dbgirq_ctx
#ifdef CONFIG_SMP
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
mfspr r8,SPRN_PIR; \
slwi r8,r8,2; \
addis r8,r8,level##_STACK_BASE@ha; \
lwz r8,level##_STACK_BASE@l(r8); \
addi r8,r8,THREAD_SIZE - INT_FRAME_SIZE;
#else
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
lis r8,level##_STACK_BASE@ha; \
lwz r8,level##_STACK_BASE@l(r8); \
addi r8,r8,THREAD_SIZE - INT_FRAME_SIZE;
#endif
/*
* Exception prolog for critical/machine check exceptions. This is a
* little different from the normal exception prolog above since a
* critical/machine check exception can potentially occur at any point
* during normal exception processing. Thus we cannot use the same SPRG
* registers as the normal prolog above. Instead we use a portion of the
* critical/machine check exception stack at low physical addresses.
*/
#define EXC_LEVEL_EXCEPTION_PROLOG(exc_level, trapno, intno, exc_level_srr0, exc_level_srr1) \
mtspr SPRN_SPRG_WSCRATCH_##exc_level,r8; \
BOOKE_LOAD_EXC_LEVEL_STACK(exc_level);/* r8 points to the exc_level stack*/ \
stw r9,GPR9(r8); /* save various registers */\
mfcr r9; /* save CR in r9 for now */\
stw r10,GPR10(r8); \
stw r11,GPR11(r8); \
stw r9,_CCR(r8); /* save CR on stack */\
mfspr r11,exc_level_srr1; /* check whether user or kernel */\
DO_KVM BOOKE_INTERRUPT_##intno exc_level_srr1; \
BOOKE_CLEAR_BTB(r10) \
andi. r11,r11,MSR_PR; \
LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)); \
mtmsr r11; \
mfspr r11,SPRN_SPRG_THREAD; /* if from user, start at top of */\
lwz r11, TASK_STACK - THREAD(r11); /* this thread's kernel stack */\
addi r11,r11,THREAD_SIZE - INT_FRAME_SIZE; /* allocate stack frame */\
beq 1f; \
/* COMING FROM USER MODE */ \
stw r9,_CCR(r11); /* save CR */\
lwz r10,GPR10(r8); /* copy regs from exception stack */\
lwz r9,GPR9(r8); \
stw r10,GPR10(r11); \
lwz r10,GPR11(r8); \
stw r9,GPR9(r11); \
stw r10,GPR11(r11); \
b 2f; \
/* COMING FROM PRIV MODE */ \
1: mr r11, r8; \
2: mfspr r8,SPRN_SPRG_RSCRATCH_##exc_level; \
stw r12,GPR12(r11); /* save various registers */\
mflr r10; \
stw r10,_LINK(r11); \
mfspr r12,SPRN_DEAR; /* save DEAR and ESR in the frame */\
stw r12,_DEAR(r11); /* since they may have had stuff */\
mfspr r9,SPRN_ESR; /* in them at the point where the */\
stw r9,_ESR(r11); /* exception was taken */\
mfspr r12,exc_level_srr0; \
stw r1,GPR1(r11); \
mfspr r9,exc_level_srr1; \
stw r1,0(r11); \
mr r1,r11; \
rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\
COMMON_EXCEPTION_PROLOG_END trapno
#define SAVE_xSRR(xSRR) \
mfspr r0,SPRN_##xSRR##0; \
stw r0,_##xSRR##0(r1); \
mfspr r0,SPRN_##xSRR##1; \
stw r0,_##xSRR##1(r1)
.macro SAVE_MMU_REGS
#ifdef CONFIG_PPC_BOOK3E_MMU
mfspr r0,SPRN_MAS0
stw r0,MAS0(r1)
mfspr r0,SPRN_MAS1
stw r0,MAS1(r1)
mfspr r0,SPRN_MAS2
stw r0,MAS2(r1)
mfspr r0,SPRN_MAS3
stw r0,MAS3(r1)
mfspr r0,SPRN_MAS6
stw r0,MAS6(r1)
#ifdef CONFIG_PHYS_64BIT
mfspr r0,SPRN_MAS7
stw r0,MAS7(r1)
#endif /* CONFIG_PHYS_64BIT */
#endif /* CONFIG_PPC_BOOK3E_MMU */
#ifdef CONFIG_44x
mfspr r0,SPRN_MMUCR
stw r0,MMUCR(r1)
#endif
.endm
#define CRITICAL_EXCEPTION_PROLOG(trapno, intno) \
EXC_LEVEL_EXCEPTION_PROLOG(CRIT, trapno+2, intno, SPRN_CSRR0, SPRN_CSRR1)
#define DEBUG_EXCEPTION_PROLOG(trapno) \
EXC_LEVEL_EXCEPTION_PROLOG(DBG, trapno+8, DEBUG, SPRN_DSRR0, SPRN_DSRR1)
#define MCHECK_EXCEPTION_PROLOG(trapno) \
EXC_LEVEL_EXCEPTION_PROLOG(MC, trapno+4, MACHINE_CHECK, \
SPRN_MCSRR0, SPRN_MCSRR1)
/*
* Guest Doorbell -- this is a bit odd in that uses GSRR0/1 despite
* being delivered to the host. This exception can only happen
* inside a KVM guest -- so we just handle up to the DO_KVM rather
* than try to fit this into one of the existing prolog macros.
*/
#define GUEST_DOORBELL_EXCEPTION \
START_EXCEPTION(GuestDoorbell); \
mtspr SPRN_SPRG_WSCRATCH0, r10; /* save one register */ \
mfspr r10, SPRN_SPRG_THREAD; \
stw r11, THREAD_NORMSAVE(0)(r10); \
mfspr r11, SPRN_SRR1; \
stw r13, THREAD_NORMSAVE(2)(r10); \
mfcr r13; /* save CR in r13 for now */\
DO_KVM BOOKE_INTERRUPT_GUEST_DBELL SPRN_GSRR1; \
trap
/*
* Exception vectors.
*/
#define START_EXCEPTION(label) \
.align 5; \
label:
#define EXCEPTION(n, intno, label, hdlr) \
START_EXCEPTION(label); \
NORMAL_EXCEPTION_PROLOG(n, intno); \
prepare_transfer_to_handler; \
bl hdlr; \
b interrupt_return
#define CRITICAL_EXCEPTION(n, intno, label, hdlr) \
START_EXCEPTION(label); \
CRITICAL_EXCEPTION_PROLOG(n, intno); \
SAVE_MMU_REGS; \
SAVE_xSRR(SRR); \
prepare_transfer_to_handler; \
bl hdlr; \
b ret_from_crit_exc
#define MCHECK_EXCEPTION(n, label, hdlr) \
START_EXCEPTION(label); \
MCHECK_EXCEPTION_PROLOG(n); \
mfspr r5,SPRN_ESR; \
stw r5,_ESR(r11); \
SAVE_xSRR(DSRR); \
SAVE_xSRR(CSRR); \
SAVE_MMU_REGS; \
SAVE_xSRR(SRR); \
prepare_transfer_to_handler; \
bl hdlr; \
b ret_from_mcheck_exc
/* Check for a single step debug exception while in an exception
* handler before state has been saved. This is to catch the case
* where an instruction that we are trying to single step causes
* an exception (eg ITLB/DTLB miss) and thus the first instruction of
* the exception handler generates a single step debug exception.
*
* If we get a debug trap on the first instruction of an exception handler,
* we reset the MSR_DE in the _exception handler's_ MSR (the debug trap is
* a critical exception, so we are using SPRN_CSRR1 to manipulate the MSR).
* The exception handler was handling a non-critical interrupt, so it will
* save (and later restore) the MSR via SPRN_CSRR1, which will still have
* the MSR_DE bit set.
*/
#define DEBUG_DEBUG_EXCEPTION \
START_EXCEPTION(DebugDebug); \
DEBUG_EXCEPTION_PROLOG(2000); \
\
/* \
* If there is a single step or branch-taken exception in an \
* exception entry sequence, it was probably meant to apply to \
* the code where the exception occurred (since exception entry \
* doesn't turn off DE automatically). We simulate the effect \
* of turning off DE on entry to an exception handler by turning \
* off DE in the DSRR1 value and clearing the debug status. \
*/ \
mfspr r10,SPRN_DBSR; /* check single-step/branch taken */ \
andis. r10,r10,(DBSR_IC|DBSR_BT)@h; \
beq+ 2f; \
\
lis r10,interrupt_base@h; /* check if exception in vectors */ \
ori r10,r10,interrupt_base@l; \
cmplw r12,r10; \
blt+ 2f; /* addr below exception vectors */ \
\
lis r10,interrupt_end@h; \
ori r10,r10,interrupt_end@l; \
cmplw r12,r10; \
bgt+ 2f; /* addr above exception vectors */ \
\
/* here it looks like we got an inappropriate debug exception. */ \
1: rlwinm r9,r9,0,~MSR_DE; /* clear DE in the CDRR1 value */ \
lis r10,(DBSR_IC|DBSR_BT)@h; /* clear the IC event */ \
mtspr SPRN_DBSR,r10; \
/* restore state and get out */ \
lwz r10,_CCR(r11); \
lwz r0,GPR0(r11); \
lwz r1,GPR1(r11); \
mtcrf 0x80,r10; \
mtspr SPRN_DSRR0,r12; \
mtspr SPRN_DSRR1,r9; \
lwz r9,GPR9(r11); \
lwz r12,GPR12(r11); \
mtspr SPRN_SPRG_WSCRATCH_DBG,r8; \
BOOKE_LOAD_EXC_LEVEL_STACK(DBG); /* r8 points to the debug stack */ \
lwz r10,GPR10(r8); \
lwz r11,GPR11(r8); \
mfspr r8,SPRN_SPRG_RSCRATCH_DBG; \
\
PPC_RFDI; \
b .; \
\
/* continue normal handling for a debug exception... */ \
2: mfspr r4,SPRN_DBSR; \
stw r4,_ESR(r11); /* DebugException takes DBSR in _ESR */\
SAVE_xSRR(CSRR); \
SAVE_MMU_REGS; \
SAVE_xSRR(SRR); \
prepare_transfer_to_handler; \
bl DebugException; \
b ret_from_debug_exc
#define DEBUG_CRIT_EXCEPTION \
START_EXCEPTION(DebugCrit); \
CRITICAL_EXCEPTION_PROLOG(2000,DEBUG); \
\
/* \
* If there is a single step or branch-taken exception in an \
* exception entry sequence, it was probably meant to apply to \
* the code where the exception occurred (since exception entry \
* doesn't turn off DE automatically). We simulate the effect \
* of turning off DE on entry to an exception handler by turning \
* off DE in the CSRR1 value and clearing the debug status. \
*/ \
mfspr r10,SPRN_DBSR; /* check single-step/branch taken */ \
andis. r10,r10,(DBSR_IC|DBSR_BT)@h; \
beq+ 2f; \
\
lis r10,interrupt_base@h; /* check if exception in vectors */ \
ori r10,r10,interrupt_base@l; \
cmplw r12,r10; \
blt+ 2f; /* addr below exception vectors */ \
\
lis r10,interrupt_end@h; \
ori r10,r10,interrupt_end@l; \
cmplw r12,r10; \
bgt+ 2f; /* addr above exception vectors */ \
\
/* here it looks like we got an inappropriate debug exception. */ \
1: rlwinm r9,r9,0,~MSR_DE; /* clear DE in the CSRR1 value */ \
lis r10,(DBSR_IC|DBSR_BT)@h; /* clear the IC event */ \
mtspr SPRN_DBSR,r10; \
/* restore state and get out */ \
lwz r10,_CCR(r11); \
lwz r0,GPR0(r11); \
lwz r1,GPR1(r11); \
mtcrf 0x80,r10; \
mtspr SPRN_CSRR0,r12; \
mtspr SPRN_CSRR1,r9; \
lwz r9,GPR9(r11); \
lwz r12,GPR12(r11); \
mtspr SPRN_SPRG_WSCRATCH_CRIT,r8; \
BOOKE_LOAD_EXC_LEVEL_STACK(CRIT); /* r8 points to the debug stack */ \
lwz r10,GPR10(r8); \
lwz r11,GPR11(r8); \
mfspr r8,SPRN_SPRG_RSCRATCH_CRIT; \
\
rfci; \
b .; \
\
/* continue normal handling for a critical exception... */ \
2: mfspr r4,SPRN_DBSR; \
stw r4,_ESR(r11); /* DebugException takes DBSR in _ESR */\
SAVE_MMU_REGS; \
SAVE_xSRR(SRR); \
prepare_transfer_to_handler; \
bl DebugException; \
b ret_from_crit_exc
#define DATA_STORAGE_EXCEPTION \
START_EXCEPTION(DataStorage) \
NORMAL_EXCEPTION_PROLOG(0x300, DATA_STORAGE); \
mfspr r5,SPRN_ESR; /* Grab the ESR and save it */ \
stw r5,_ESR(r11); \
mfspr r4,SPRN_DEAR; /* Grab the DEAR */ \
stw r4, _DEAR(r11); \
prepare_transfer_to_handler; \
bl do_page_fault; \
b interrupt_return
#define INSTRUCTION_STORAGE_EXCEPTION \
START_EXCEPTION(InstructionStorage) \
NORMAL_EXCEPTION_PROLOG(0x400, INST_STORAGE); \
mfspr r5,SPRN_ESR; /* Grab the ESR and save it */ \
stw r5,_ESR(r11); \
stw r12, _DEAR(r11); /* Pass SRR0 as arg2 */ \
prepare_transfer_to_handler; \
bl do_page_fault; \
b interrupt_return
#define ALIGNMENT_EXCEPTION \
START_EXCEPTION(Alignment) \
NORMAL_EXCEPTION_PROLOG(0x600, ALIGNMENT); \
mfspr r4,SPRN_DEAR; /* Grab the DEAR and save it */ \
stw r4,_DEAR(r11); \
prepare_transfer_to_handler; \
bl alignment_exception; \
REST_NVGPRS(r1); \
b interrupt_return
#define PROGRAM_EXCEPTION \
START_EXCEPTION(Program) \
NORMAL_EXCEPTION_PROLOG(0x700, PROGRAM); \
mfspr r4,SPRN_ESR; /* Grab the ESR and save it */ \
stw r4,_ESR(r11); \
prepare_transfer_to_handler; \
bl program_check_exception; \
REST_NVGPRS(r1); \
b interrupt_return
#define DECREMENTER_EXCEPTION \
START_EXCEPTION(Decrementer) \
NORMAL_EXCEPTION_PROLOG(0x900, DECREMENTER); \
lis r0,TSR_DIS@h; /* Setup the DEC interrupt mask */ \
mtspr SPRN_TSR,r0; /* Clear the DEC interrupt */ \
prepare_transfer_to_handler; \
bl timer_interrupt; \
b interrupt_return
#define FP_UNAVAILABLE_EXCEPTION \
START_EXCEPTION(FloatingPointUnavailable) \
NORMAL_EXCEPTION_PROLOG(0x800, FP_UNAVAIL); \
beq 1f; \
bl load_up_fpu; /* if from user, just load it up */ \
b fast_exception_return; \
1: prepare_transfer_to_handler; \
bl kernel_fp_unavailable_exception; \
b interrupt_return
#endif /* __ASSEMBLY__ */
#endif /* __HEAD_BOOKE_H__ */
|
