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
|
###############################################################################
#
# switch_to.S: context switch operation
#
# Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
# Written by David Howells (dhowells@redhat.com)
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version
# 2 of the License, or (at your option) any later version.
#
###############################################################################
#include <linux/linkage.h>
#include <asm/thread_info.h>
#include <asm/processor.h>
#include <asm/registers.h>
#include <asm/spr-regs.h>
.macro LEDS val
setlos #~\val,gr27
st gr27,@(gr30,gr0)
membar
dcf @(gr30,gr0)
.endm
.section .sdata
.balign 8
# address of frame 0 (userspace) on current kernel stack
.globl __kernel_frame0_ptr
__kernel_frame0_ptr:
.long init_thread_union + THREAD_SIZE - FRV_FRAME0_SIZE
# address of current task
.globl __kernel_current_task
__kernel_current_task:
.long init_task
.section .text
.balign 4
###############################################################################
#
# struct task_struct *__switch_to(struct thread_struct *prev_thread,
# struct thread_struct *next_thread,
# struct task_struct *prev)
#
###############################################################################
.globl __switch_to
__switch_to:
# save outgoing process's context
sethi.p %hi(__switch_back),gr13
setlo %lo(__switch_back),gr13
movsg lr,gr12
stdi gr28,@(gr8,#__THREAD_FRAME)
sti sp ,@(gr8,#__THREAD_SP)
sti fp ,@(gr8,#__THREAD_FP)
stdi gr12,@(gr8,#__THREAD_LR)
stdi gr16,@(gr8,#__THREAD_GR(16))
stdi gr18,@(gr8,#__THREAD_GR(18))
stdi gr20,@(gr8,#__THREAD_GR(20))
stdi gr22,@(gr8,#__THREAD_GR(22))
stdi gr24,@(gr8,#__THREAD_GR(24))
stdi.p gr26,@(gr8,#__THREAD_GR(26))
or gr8,gr8,gr22
ldi.p @(gr8,#__THREAD_USER),gr8
call save_user_regs
or gr22,gr22,gr8
# retrieve the new context
sethi.p %hi(__kernel_frame0_ptr),gr6
setlo %lo(__kernel_frame0_ptr),gr6
movsg psr,gr4
lddi.p @(gr9,#__THREAD_FRAME),gr10
or gr10,gr10,gr27 ; save prev for the return value
ldi @(gr11,#4),gr19 ; get new_current->thread_info
lddi @(gr9,#__THREAD_SP),gr12
ldi @(gr9,#__THREAD_LR),gr14
ldi @(gr9,#__THREAD_PC),gr18
ldi.p @(gr9,#__THREAD_FRAME0),gr7
# actually switch kernel contexts with ordinary exceptions disabled
andi gr4,#~PSR_ET,gr5
movgs gr5,psr
or.p gr10,gr0,gr28 ; set __frame
or gr11,gr0,gr29 ; set __current
or.p gr12,gr0,sp
or gr13,gr0,fp
or gr19,gr0,gr15 ; set __current_thread_info
sti gr7,@(gr6,#0) ; set __kernel_frame0_ptr
sti gr29,@(gr6,#4) ; set __kernel_current_task
movgs gr14,lr
bar
# jump to __switch_back or ret_from_fork as appropriate
# - move prev to GR8
movgs gr4,psr
jmpl.p @(gr18,gr0)
or gr27,gr27,gr8
###############################################################################
#
# restore incoming process's context
# - on entry:
# - SP, FP, LR, GR15, GR28 and GR29 will have been set up appropriately
# - GR8 will point to the outgoing task_struct
# - GR9 will point to the incoming thread_struct
#
###############################################################################
__switch_back:
lddi @(gr9,#__THREAD_GR(16)),gr16
lddi @(gr9,#__THREAD_GR(18)),gr18
lddi @(gr9,#__THREAD_GR(20)),gr20
lddi @(gr9,#__THREAD_GR(22)),gr22
lddi @(gr9,#__THREAD_GR(24)),gr24
lddi @(gr9,#__THREAD_GR(26)),gr26
# fall through into restore_user_regs()
ldi.p @(gr9,#__THREAD_USER),gr8
or gr8,gr8,gr9
###############################################################################
#
# restore extra general regs and FP/Media regs
# - void *restore_user_regs(const struct user_context *target, void *retval)
# - on entry:
# - GR8 will point to the user context to swap in
# - GR9 will contain the value to be returned in GR8 (prev task on context switch)
#
###############################################################################
.globl restore_user_regs
restore_user_regs:
movsg hsr0,gr6
ori gr6,#HSR0_GRHE|HSR0_FRLE|HSR0_FRHE,gr6
movgs gr6,hsr0
movsg hsr0,gr6
movsg psr,gr7
ori gr7,#PSR_EF|PSR_EM,gr7
movgs gr7,psr
movsg psr,gr7
srli gr7,#24,gr7
bar
lddi @(gr8,#__FPMEDIA_MSR(0)),gr4
movgs gr4,msr0
movgs gr5,msr1
lddfi @(gr8,#__FPMEDIA_ACC(0)),fr16
lddfi @(gr8,#__FPMEDIA_ACC(2)),fr18
ldbfi @(gr8,#__FPMEDIA_ACCG(0)),fr20
ldbfi @(gr8,#__FPMEDIA_ACCG(1)),fr21
ldbfi @(gr8,#__FPMEDIA_ACCG(2)),fr22
ldbfi @(gr8,#__FPMEDIA_ACCG(3)),fr23
mwtacc fr16,acc0
mwtacc fr17,acc1
mwtacc fr18,acc2
mwtacc fr19,acc3
mwtaccg fr20,accg0
mwtaccg fr21,accg1
mwtaccg fr22,accg2
mwtaccg fr23,accg3
# some CPUs have extra ACCx and ACCGx regs and maybe FSRx regs
subicc.p gr7,#0x50,gr0,icc0
subicc gr7,#0x31,gr0,icc1
beq icc0,#0,__restore_acc_fr451
beq icc1,#0,__restore_acc_fr555
__restore_acc_cont:
# some CPU's have GR32-GR63
setlos #HSR0_FRHE,gr4
andcc gr6,gr4,gr0,icc0
beq icc0,#1,__restore_skip_gr32_gr63
lddi @(gr8,#__INT_GR(32)),gr32
lddi @(gr8,#__INT_GR(34)),gr34
lddi @(gr8,#__INT_GR(36)),gr36
lddi @(gr8,#__INT_GR(38)),gr38
lddi @(gr8,#__INT_GR(40)),gr40
lddi @(gr8,#__INT_GR(42)),gr42
lddi @(gr8,#__INT_GR(44)),gr44
lddi @(gr8,#__INT_GR(46)),gr46
lddi @(gr8,#__INT_GR(48)),gr48
lddi @(gr8,#__INT_GR(50)),gr50
lddi @(gr8,#__INT_GR(52)),gr52
lddi @(gr8,#__INT_GR(54)),gr54
lddi @(gr8,#__INT_GR(56)),gr56
lddi @(gr8,#__INT_GR(58)),gr58
lddi @(gr8,#__INT_GR(60)),gr60
lddi @(gr8,#__INT_GR(62)),gr62
__restore_skip_gr32_gr63:
# all CPU's have FR0-FR31
lddfi @(gr8,#__FPMEDIA_FR( 0)),fr0
lddfi @(gr8,#__FPMEDIA_FR( 2)),fr2
lddfi @(gr8,#__FPMEDIA_FR( 4)),fr4
lddfi @(gr8,#__FPMEDIA_FR( 6)),fr6
lddfi @(gr8,#__FPMEDIA_FR( 8)),fr8
lddfi @(gr8,#__FPMEDIA_FR(10)),fr10
lddfi @(gr8,#__FPMEDIA_FR(12)),fr12
lddfi @(gr8,#__FPMEDIA_FR(14)),fr14
lddfi @(gr8,#__FPMEDIA_FR(16)),fr16
lddfi @(gr8,#__FPMEDIA_FR(18)),fr18
lddfi @(gr8,#__FPMEDIA_FR(20)),fr20
lddfi @(gr8,#__FPMEDIA_FR(22)),fr22
lddfi @(gr8,#__FPMEDIA_FR(24)),fr24
lddfi @(gr8,#__FPMEDIA_FR(26)),fr26
lddfi @(gr8,#__FPMEDIA_FR(28)),fr28
lddfi.p @(gr8,#__FPMEDIA_FR(30)),fr30
# some CPU's have FR32-FR63
setlos #HSR0_FRHE,gr4
andcc gr6,gr4,gr0,icc0
beq icc0,#1,__restore_skip_fr32_fr63
lddfi @(gr8,#__FPMEDIA_FR(32)),fr32
lddfi @(gr8,#__FPMEDIA_FR(34)),fr34
lddfi @(gr8,#__FPMEDIA_FR(36)),fr36
lddfi @(gr8,#__FPMEDIA_FR(38)),fr38
lddfi @(gr8,#__FPMEDIA_FR(40)),fr40
lddfi @(gr8,#__FPMEDIA_FR(42)),fr42
lddfi @(gr8,#__FPMEDIA_FR(44)),fr44
lddfi @(gr8,#__FPMEDIA_FR(46)),fr46
lddfi @(gr8,#__FPMEDIA_FR(48)),fr48
lddfi @(gr8,#__FPMEDIA_FR(50)),fr50
lddfi @(gr8,#__FPMEDIA_FR(52)),fr52
lddfi @(gr8,#__FPMEDIA_FR(54)),fr54
lddfi @(gr8,#__FPMEDIA_FR(56)),fr56
lddfi @(gr8,#__FPMEDIA_FR(58)),fr58
lddfi @(gr8,#__FPMEDIA_FR(60)),fr60
lddfi @(gr8,#__FPMEDIA_FR(62)),fr62
__restore_skip_fr32_fr63:
lddi @(gr8,#__FPMEDIA_FNER(0)),gr4
movsg fner0,gr4
movsg fner1,gr5
or.p gr9,gr9,gr8
bralr
# the FR451 also has ACC8-11/ACCG8-11 regs (but not 4-7...)
__restore_acc_fr451:
lddfi @(gr8,#__FPMEDIA_ACC(4)),fr16
lddfi @(gr8,#__FPMEDIA_ACC(6)),fr18
ldbfi @(gr8,#__FPMEDIA_ACCG(4)),fr20
ldbfi @(gr8,#__FPMEDIA_ACCG(5)),fr21
ldbfi @(gr8,#__FPMEDIA_ACCG(6)),fr22
ldbfi @(gr8,#__FPMEDIA_ACCG(7)),fr23
mwtacc fr16,acc8
mwtacc fr17,acc9
mwtacc fr18,acc10
mwtacc fr19,acc11
mwtaccg fr20,accg8
mwtaccg fr21,accg9
mwtaccg fr22,accg10
mwtaccg fr23,accg11
bra __restore_acc_cont
# the FR555 also has ACC4-7/ACCG4-7 regs and an FSR0 reg
__restore_acc_fr555:
lddfi @(gr8,#__FPMEDIA_ACC(4)),fr16
lddfi @(gr8,#__FPMEDIA_ACC(6)),fr18
ldbfi @(gr8,#__FPMEDIA_ACCG(4)),fr20
ldbfi
|