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
|
/*
* arch/mips/dec/int-handler.S
*
* Copyright (C) 1995, 1996, 1997 Paul M. Antoine and Harald Koerfgen
* Copyright (C) 2000, 2001, 2002, 2003, 2005 Maciej W. Rozycki
*
* Written by Ralf Baechle and Andreas Busse, modified for DECstation
* support by Paul Antoine and Harald Koerfgen.
*
* completly rewritten:
* Copyright (C) 1998 Harald Koerfgen
*
* Rewritten extensively for controller-driven IRQ support
* by Maciej W. Rozycki.
*/
#include <linux/config.h>
#include <asm/addrspace.h>
#include <asm/asm.h>
#include <asm/mipsregs.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/dec/interrupts.h>
#include <asm/dec/ioasic_addrs.h>
#include <asm/dec/ioasic_ints.h>
#include <asm/dec/kn01.h>
#include <asm/dec/kn02.h>
#include <asm/dec/kn02xa.h>
#include <asm/dec/kn03.h>
#define KN02_CSR_BASE CKSEG1ADDR(KN02_SLOT_BASE + KN02_CSR)
#define KN02XA_IOASIC_BASE CKSEG1ADDR(KN02XA_SLOT_BASE + IOASIC_IOCTL)
#define KN03_IOASIC_BASE CKSEG1ADDR(KN03_SLOT_BASE + IOASIC_IOCTL)
.text
.set noreorder
/*
* decstation_handle_int: Interrupt handler for DECstations
*
* We follow the model in the Indy interrupt code by David Miller, where he
* says: a lot of complication here is taken away because:
*
* 1) We handle one interrupt and return, sitting in a loop
* and moving across all the pending IRQ bits in the cause
* register is _NOT_ the answer, the common case is one
* pending IRQ so optimize in that direction.
*
* 2) We need not check against bits in the status register
* IRQ mask, that would make this routine slow as hell.
*
* 3) Linux only thinks in terms of all IRQs on or all IRQs
* off, nothing in between like BSD spl() brain-damage.
*
* Furthermore, the IRQs on the DECstations look basically (barring
* software IRQs which we don't use at all) like...
*
* DS2100/3100's, aka kn01, aka Pmax:
*
* MIPS IRQ Source
* -------- ------
* 0 Software (ignored)
* 1 Software (ignored)
* 2 SCSI
* 3 Lance Ethernet
* 4 DZ11 serial
* 5 RTC
* 6 Memory Controller & Video
* 7 FPU
*
* DS5000/200, aka kn02, aka 3max:
*
* MIPS IRQ Source
* -------- ------
* 0 Software (ignored)
* 1 Software (ignored)
* 2 TurboChannel
* 3 RTC
* 4 Reserved
* 5 Memory Controller
* 6 Reserved
* 7 FPU
*
* DS5000/1xx's, aka kn02ba, aka 3min:
*
* MIPS IRQ Source
* -------- ------
* 0 Software (ignored)
* 1 Software (ignored)
* 2 TurboChannel Slot 0
* 3 TurboChannel Slot 1
* 4 TurboChannel Slot 2
* 5 TurboChannel Slot 3 (ASIC)
* 6 Halt button
* 7 FPU/R4k timer
*
* DS5000/2x's, aka kn02ca, aka maxine:
*
* MIPS IRQ Source
* -------- ------
* 0 Software (ignored)
* 1 Software (ignored)
* 2 Periodic Interrupt (100usec)
* 3 RTC
* 4 I/O write timeout
* 5 TurboChannel (ASIC)
* 6 Halt Keycode from Access.Bus keyboard (CTRL-ALT-ENTER)
* 7 FPU/R4k timer
*
* DS5000/2xx's, aka kn03, aka 3maxplus:
*
* MIPS IRQ Source
* -------- ------
* 0 Software (ignored)
* 1 Software (ignored)
* 2 System Board (ASIC)
* 3 RTC
* 4 Reserved
* 5 Memory
* 6 Halt Button
* 7 FPU/R4k timer
*
* We handle the IRQ according to _our_ priority (see setup.c),
* then we just return. If multiple IRQs are pending then we will
* just take another exception, big deal.
*/
.align 5
NESTED(decstation_handle_int, PT_SIZE, ra)
.set noat
SAVE_ALL
CLI # TEST: interrupts should be off
.set at
.set noreorder
/*
* Get pending Interrupts
*/
mfc0 t0,CP0_CAUSE # get pending interrupts
mfc0 t1,CP0_STATUS
#ifdef CONFIG_32BIT
lw t2,cpu_fpu_mask
#endif
andi t0,ST0_IM # CAUSE.CE may be non-zero!
and t0,t1 # isolate allowed ones
beqz t0,spurious
#ifdef CONFIG_32BIT
and t2,t0
bnez t2,fpu # handle FPU immediately
#endif
/*
* Find irq with highest priority
*/
PTR_LA t1,cpu_mask_nr_tbl
1: lw t2,(t1)
nop
and t2,t0
beqz t2,1b
addu t1,2*PTRSIZE # delay slot
/*
* Do the low-level stuff
*/
lw a0,(-PTRSIZE)(t1)
nop
bgez a0,handle_it # irq_nr >= 0?
# irq_nr < 0: it is an address
nop
jr a0
# a trick to save a branch:
lui t2,(KN03_IOASIC_BASE>>16)&0xffff
# upper part of IOASIC Address
/*
* Handle "IRQ Controller" Interrupts
* Masked Interrupts are still visible and have to be masked "by hand".
*/
FEXPORT(kn02_io_int) # 3max
lui t0,(KN02_CSR_BASE>>16)&0xffff
# get interrupt status and mask
lw t0,(t0)
nop
andi t1,t0,KN02_IRQ_ALL
b 1f
srl t0,16 # shift interrupt mask
FEXPORT(kn02xa_io_int) # 3min/maxine
lui t2,(KN02XA_IOASIC_BASE>>16)&0xffff
# upper part of IOASIC Address
FEXPORT(kn03_io_int) # 3max+ (t2 loaded earlier)
lw t0,IO_REG_SIR(t2) # get status: IOASIC sir
lw t1,IO_REG_SIMR(t2) # get mask: IOASIC simr
nop
1: and t0,t1 # mask out allowed ones
beqz t0,spurious
/*
* Find irq with highest priority
*/
PTR_LA t1,asic_mask_nr_tbl
2: lw t2,(t1)
nop
and t2,t0
beq zero,t2,2b
addu t1,2*PTRSIZE # delay slot
/*
* Do the low-level stuff
*/
lw a0,%lo(-PTRSIZE)(t1)
nop
bgez a0,handle_it # irq_nr >= 0?
# irq_nr < 0: it is an address
nop
jr a0
nop # delay slot
/*
* Dispatch low-priority interrupts. We reconsider all status
* bits again, which looks like a lose, but it makes the code
* simple and O(log n), so it gets compensated.
*/
FEXPORT(cpu_all_int) # HALT, timers, software junk
li a0,DEC_CPU_IRQ_BASE
srl t0,CAUSEB_IP
li t1,CAUSEF_IP>>CAUSEB_IP # mask
b 1f
li t2,4 # nr of bits / 2
FEXPORT(kn02_all_int) # impossible ?
li a0,KN02_IRQ_BASE
li t1,KN02_IRQ_ALL # mask
b 1f
li t2,4 # nr of bits / 2
FEXPORT(asic_all_int) # various I/O ASIC junk
li a0,IO_IRQ_BASE
li t1,IO_IRQ_ALL # mask
b 1f
li t2,8 # nr of bits / 2
/*
* Dispatch DMA interrupts -- O(log n).
*/
FEXPORT(asic_dma_int) # I/O ASIC DMA events
li a0,IO_IRQ_BASE+IO_INR_DMA
srl t0,IO_INR_DMA
li t1,IO_IRQ_DMA>>IO_INR_DMA # mask
li t2,8 # nr of bits / 2
/*
* Find irq with highest priority.
* Highest irq number takes precedence.
*/
1: srlv t3,t1,t2
2: xor t1,t3
and t3,t0,t1
beqz t3,3f
nop
move t0,t3
addu a0,t2
3: srl t2,1
bnez t2,2b
srlv t3,t1,t2
handle_it:
jal do_IRQ
move a1,sp
j ret_from_irq
nop
#ifdef CONFIG_32BIT
fpu:
j handle_fpe_int
nop
#endif
spurious:
j spurious_interrupt
nop
END(decstation_handle_int)
/*
* Generic unimplemented interrupt routines -- cpu_mask_nr_tbl
* and asic_mask_nr_tbl are initialized to point all interrupts here.
* The tables are then filled in by machine-specific initialisation
* in dec_setup().
*/
FEXPORT(dec_intr_unimplemented)
move a1,t0 # cheats way of printing an arg!
PANIC("Unimplemented cpu interrupt! CP0_CAUSE: 0x%08x");
FEXPORT(asic_intr_unimplemented)
move a1,t0 # cheats way of printing an arg!
PANIC("Unimplemented asic interrupt! ASIC ISR: 0x%08x");
|
