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
|
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright 2015, Cyril Bur, IBM Corp.
*/
#include "basic_asm.h"
#include "fpu_asm.h"
FUNC_START(check_fpu)
mr r4,r3
li r3,1 # assume a bad result
lfd f0,0(r4)
fcmpu cr1,f0,f14
bne cr1,1f
lfd f0,8(r4)
fcmpu cr1,f0,f15
bne cr1,1f
lfd f0,16(r4)
fcmpu cr1,f0,f16
bne cr1,1f
lfd f0,24(r4)
fcmpu cr1,f0,f17
bne cr1,1f
lfd f0,32(r4)
fcmpu cr1,f0,f18
bne cr1,1f
lfd f0,40(r4)
fcmpu cr1,f0,f19
bne cr1,1f
lfd f0,48(r4)
fcmpu cr1,f0,f20
bne cr1,1f
lfd f0,56(r4)
fcmpu cr1,f0,f21
bne cr1,1f
lfd f0,64(r4)
fcmpu cr1,f0,f22
bne cr1,1f
lfd f0,72(r4)
fcmpu cr1,f0,f23
bne cr1,1f
lfd f0,80(r4)
fcmpu cr1,f0,f24
bne cr1,1f
lfd f0,88(r4)
fcmpu cr1,f0,f25
bne cr1,1f
lfd f0,96(r4)
fcmpu cr1,f0,f26
bne cr1,1f
lfd f0,104(r4)
fcmpu cr1,f0,f27
bne cr1,1f
lfd f0,112(r4)
fcmpu cr1,f0,f28
bne cr1,1f
lfd f0,120(r4)
fcmpu cr1,f0,f29
bne cr1,1f
lfd f0,128(r4)
fcmpu cr1,f0,f30
bne cr1,1f
lfd f0,136(r4)
fcmpu cr1,f0,f31
bne cr1,1f
li r3,0 # Success!!!
1: blr
FUNC_START(test_fpu)
# r3 holds pointer to where to put the result of fork
# r4 holds pointer to the pid
# f14-f31 are non volatiles
PUSH_BASIC_STACK(256)
PUSH_FPU(256)
std r3,STACK_FRAME_PARAM(0)(sp) # Address of darray
std r4,STACK_FRAME_PARAM(1)(sp) # Address of pid
bl load_fpu
nop
li r0,__NR_fork
sc
# pass the result of the fork to the caller
ld r9,STACK_FRAME_PARAM(1)(sp)
std r3,0(r9)
ld r3,STACK_FRAME_PARAM(0)(sp)
bl check_fpu
nop
POP_FPU(256)
POP_BASIC_STACK(256)
blr
FUNC_END(test_fpu)
# int preempt_fpu(double *darray, int *threads_running, int *running)
# On starting will (atomically) decrement not_ready as a signal that the FPU
# has been loaded with darray. Will proceed to check the validity of the FPU
# registers while running is not zero.
FUNC_START(preempt_fpu)
PUSH_BASIC_STACK(256)
PUSH_FPU(256)
std r3,STACK_FRAME_PARAM(0)(sp) # double *darray
std r4,STACK_FRAME_PARAM(1)(sp) # int *threads_starting
std r5,STACK_FRAME_PARAM(2)(sp) # int *running
bl load_fpu
nop
sync
# Atomic DEC
ld r3,STACK_FRAME_PARAM(1)(sp)
1: lwarx r4,0,r3
addi r4,r4,-1
stwcx. r4,0,r3
bne- 1b
2: ld r3,STACK_FRAME_PARAM(0)(sp)
bl check_fpu
nop
cmpdi r3,0
bne 3f
ld r4,STACK_FRAME_PARAM(2)(sp)
ld r5,0(r4)
cmpwi r5,0
bne 2b
3: POP_FPU(256)
POP_BASIC_STACK(256)
blr
FUNC_END(preempt_fpu)
|
