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
|
/*-
* Copyright (c) 1989, 1990 William F. Jolitz.
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ipl.s
*
* $Id: ipl.s,v 1.25 1999/04/11 15:51:15 peter Exp $
*/
/*
* AT/386
* Vector interrupt control section
*/
.data
ALIGN_DATA
/* current priority (all off) */
.globl _cpl
_cpl: .long HWI_MASK | SWI_MASK
.globl _tty_imask
_tty_imask: .long SWI_TTY_MASK
.globl _bio_imask
_bio_imask: .long SWI_CLOCK_MASK | SWI_CAMBIO_MASK
.globl _net_imask
_net_imask: .long SWI_NET_MASK | SWI_CAMNET_MASK
.globl _cam_imask
_cam_imask: .long SWI_CAMBIO_MASK | SWI_CAMNET_MASK
.globl _soft_imask
_soft_imask: .long SWI_MASK
.globl _softnet_imask
_softnet_imask: .long SWI_NET_MASK
.globl _softtty_imask
_softtty_imask: .long SWI_TTY_MASK
/* pending interrupts blocked by splxxx() */
.globl _ipending
_ipending: .long 0
/* set with bits for which queue to service */
.globl _netisr
_netisr: .long 0
.globl _netisrs
_netisrs:
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.text
#ifdef SMP
#ifdef notnow
#define TEST_CIL \
cmpl $0x0100, _cil ; \
jne 1f ; \
cmpl $0, _inside_intr ; \
jne 1f ; \
int $3 ; \
1:
#else
#define TEST_CIL
#endif
#endif
/*
* Handle return from interrupts, traps and syscalls.
*/
SUPERALIGN_TEXT
_doreti:
#ifdef SMP
TEST_CIL
#endif
FAKE_MCOUNT(_bintr) /* init "from" _bintr -> _doreti */
addl $4,%esp /* discard unit number */
popl %eax /* cpl or cml to restore */
doreti_next:
/*
* Check for pending HWIs and SWIs atomically with restoring cpl
* and exiting. The check has to be atomic with exiting to stop
* (ipending & ~cpl) changing from zero to nonzero while we're
* looking at it (this wouldn't be fatal but it would increase
* interrupt latency). Restoring cpl has to be atomic with exiting
* so that the stack cannot pile up (the nesting level of interrupt
* handlers is limited by the number of bits in cpl).
*/
#ifdef SMP
TEST_CIL
cli /* early to prevent INT deadlock */
pushl %eax /* preserve cpl while getting lock */
ICPL_LOCK
popl %eax
doreti_next2:
#endif
movl %eax,%ecx
#ifdef CPL_AND_CML
orl _cpl, %ecx /* add cpl to cml */
#endif
notl %ecx /* set bit = unmasked level */
#ifndef SMP
cli
#endif
andl _ipending,%ecx /* set bit = unmasked pending INT */
jne doreti_unpend
doreti_exit:
#ifdef SMP
TEST_CIL
#endif
#ifdef CPL_AND_CML
movl %eax, _cml
#else
movl %eax,_cpl
#endif
FAST_ICPL_UNLOCK /* preserves %eax */
MPLOCKED decb _intr_nesting_level
MEXITCOUNT
#ifdef VM86
#ifdef CPL_AND_CML
/* XXX CPL_AND_CML needs work */
#error not ready for vm86
#endif
cmpl $1,_in_vm86call
je 1f /* want cpl == SWI_AST_PENDING */
/*
* XXX
* Sometimes when attempting to return to vm86 mode, cpl is not
* being reset to 0, so here we force it to 0 before returning to
* vm86 mode. doreti_stop is a convenient place to set a breakpoint.
* When the cpl problem is solved, this code can disappear.
*/
ICPL_LOCK
cmpl $0,_cpl /* cpl == 0, skip it */
je 1f
testl $PSL_VM,TF_EFLAGS(%esp) /* going to VM86 mode? */
jne doreti_stop
testb $SEL_RPL_MASK,TF_CS(%esp) /* to user mode? */
je 1f
doreti_stop:
movl $0,_cpl
nop
1:
FAST_ICPL_UNLOCK /* preserves %eax */
#endif /* VM86 */
#ifdef SMP
#ifdef INTR_SIMPLELOCK
#error code needed here to decide which lock to release, INTR or giant
#endif
/* release the kernel lock */
pushl $_mp_lock /* GIANT_LOCK */
call _MPrellock
add $4, %esp
#endif /* SMP */
.globl doreti_popl_fs
doreti_popl_fs:
popl %fs
.globl doreti_popl_es
doreti_popl_es:
popl %es
.globl doreti_popl_ds
doreti_popl_ds:
popl %ds
popal
addl $8,%esp
.globl doreti_iret
doreti_iret:
iret
ALIGN_TEXT
.globl doreti_iret_fault
doreti_iret_fault:
subl $8,%esp
pushal
pushl %ds
.globl doreti_popl_ds_fault
doreti_popl_ds_fault:
pushl %es
.globl doreti_popl_es_fault
doreti_popl_es_fault:
pushl %fs
.globl doreti_popl_fs_fault
doreti_popl_fs_fault:
movl $0,TF_ERR(%esp) /* XXX should be the error code */
movl $T_PROTFLT,TF_TRAPNO(%esp)
jmp alltraps_with_regs_pushed
ALIGN_TEXT
doreti_unpend:
/*
* Enabling interrupts is safe because we haven't restored cpl yet.
* The locking from the "btrl" test is probably no longer necessary.
* We won't miss any new pending interrupts because we will check
* for them again.
*/
#ifdef SMP
TEST_CIL
/* we enter with cpl locked */
bsfl %ecx, %ecx /* slow, but not worth optimizing */
btrl %ecx, _ipending
jnc doreti_next2 /* some intr cleared memory copy */
cmpl $NHWI, %ecx
jae 1f
btsl %ecx, _cil
1:
FAST_ICPL_UNLOCK /* preserves %eax */
sti /* late to prevent INT deadlock */
#else
sti
bsfl %ecx,%ecx /* slow, but not worth optimizing */
btrl %ecx,_ipending
jnc doreti_next /* some intr cleared memory copy */
#endif /* SMP */
/*
* Set up JUMP to _ihandlers[%ecx] for HWIs.
* Set up CALL of _ihandlers[%ecx] for SWIs.
* This is a bit early for the SMP case - we have to push %ecx and
* %edx, but could push only %ecx and load %edx later.
*/
movl _ihandlers(,%ecx,4),%edx
cmpl $NHWI,%ecx
jae doreti_swi
cli
#ifdef SMP
pushl %edx /* preserve %edx */
#ifdef APIC_INTR_DIAGNOSTIC
pushl %ecx
#endif
pushl %eax /* preserve %eax */
ICPL_LOCK
#ifdef CPL_AND_CML
popl _cml
#else
popl _cpl
#endif
FAST_ICPL_UNLOCK
#ifdef APIC_INTR_DIAGNOSTIC
popl %ecx
#endif
popl %edx
#else
movl %eax,_cpl
#endif
MEXITCOUNT
#ifdef APIC_INTR_DIAGNOSTIC
lock
incl CNAME(apic_itrace_doreti)(,%ecx,4)
#ifdef APIC_INTR_DIAGNOSTIC_IRQ
cmpl $APIC_INTR_DIAGNOSTIC_IRQ,%ecx
jne 9f
pushl %eax
pushl %ecx
pushl %edx
pushl $APIC_ITRACE_DORETI
call log_intr_event
addl $4,%esp
popl %edx
popl %ecx
popl %eax
9:
#endif
#endif
jmp %edx
ALIGN_TEXT
doreti_swi:
#ifdef SMP
TEST_CIL
#endif
pushl %eax
/*
* The SWI_AST handler has to run at cpl = SWI_AST_MASK and the
* SWI_CLOCK handler at cpl = SWI_CLOCK_MASK, so we have to restore
* all the h/w bits in cpl now and have to worry about stack growth.
* The worst case is currently (30 Jan 1994) 2 SWI handlers nested
* in dying interrupt frames and about 12 HWIs nested in active
* interrupt frames. There are only 4 different SWIs and the HWI
* and SWI masks limit the nesting further.
*/
#ifdef SMP
orl imasks(,%ecx,4), %eax
pushl %ecx /* preserve for use by _swi_generic */
pushl %edx /* save handler entry point */
cli /* prevent INT deadlock */
pushl %eax /* save cpl|cml */
ICPL_LOCK
#ifdef CPL_AND_CML
popl _cml /* restore cml */
#else
popl _cpl /* restore cpl */
#endif
FAST_ICPL_UNLOCK
sti
popl %edx /* restore handler entry point */
popl %ecx
#else
orl imasks(,%ecx,4),%eax
movl %eax,_cpl
#endif
call %edx
popl %eax
jmp doreti_next
ALIGN_TEXT
swi_ast:
addl $8,%esp /* discard raddr & cpl to get trap frame */
#ifdef VM86
cmpl $1,_in_vm86call
je 1f /* stay in kernel mode */
#endif
testb $SEL_RPL_MASK,TF_CS(%esp)
je swi_ast_phantom
swi_ast_user:
movl $T_ASTFLT,TF_TRAPNO(%esp)
movb $0,_intr_nesting_level /* finish becoming a trap handler */
call _trap
subl %eax,%eax /* recover cpl|cml */
#ifdef CPL_AND_CML
movl %eax, _cpl
#endif
movb $1,_intr_nesting_level /* for doreti_next to decrement */
jmp doreti_next
ALIGN_TEXT
swi_ast_phantom:
#ifdef VM86
/*
* check for ast from vm86 mode. Placed down here so the jumps do
* not get taken for mainline code.
*/
testl $PSL_VM,TF_EFLAGS(%esp)
jne swi_ast_user
1:
#endif /* VM86 */
/*
* These happen when there is an interrupt in a trap handler before
* ASTs can be masked or in an lcall handler before they can be
* masked or after they are unmasked. They could be avoided for
* trap entries by using interrupt gates, and for lcall exits by
* using by using cli, but they are unavoidable for lcall entries.
*/
cli
ICPL_LOCK
orl $SWI_AST_PENDING, _ipending
/* cpl is unlocked in doreti_exit */
subl %eax,%eax
#ifdef CPL_AND_CML
movl %eax, _cpl
#endif
jmp doreti_exit /* SWI_AST is highest so we must be done */
ALIGN_TEXT
swi_net:
MCOUNT
bsfl _netisr,%eax
je swi_net_done
swi_net_more:
btrl %eax,_netisr
jnc swi_net_next
call *_netisrs(,%eax,4)
swi_net_next:
bsfl _netisr,%eax
jne swi_net_more
swi_net_done:
ret
ALIGN_TEXT
dummynetisr:
MCOUNT
ret
/*
* The arg is in a nonstandard place, so swi_dispatcher() can't be called
* directly and swi_generic() can't use ENTRY() or MCOUNT.
*/
ALIGN_TEXT
.globl _swi_generic
_swi_generic:
pushl %ecx
FAKE_MCOUNT(4(%esp))
call _swi_dispatcher
popl %ecx
ret
ENTRY(swi_null)
ret
#ifdef APIC_IO
#include "i386/isa/apic_ipl.s"
#else
#include "i386/isa/icu_ipl.s"
#endif /* APIC_IO */
|