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
|
/* Copyright (C) 2001, 2002 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by David Mosberger-Tang <davidm@hpl.hp.com>.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sysdep.h>
#include <features.h>
#include "ucontext_i.h"
/* __getcontext (ucontext_t *ucp)
Saves the machine context in UCP such that when it is activated,
it appears as if __getcontext() returned again. The only difference
is that on a first return, r9 contains 1 and on a subsequent
return, it contains 0.
This implementation in intended to be used for *synchronous* context
switches only. Therefore, it does not have to save anything
other than the PRESERVED state. */
ENTRY(__getcontext)
.prologue
alloc r16 = ar.pfs, 1, 0, 4, 0
// sigprocmask (SIG_BLOCK, NULL, &sc->sc_mask):
mov r2 = SC_MASK
mov r15 = __NR_rt_sigprocmask
;;
mov out0 = SIG_BLOCK
mov out1 = 0
add out2 = r2, in0
mov out3 = 8 // sizeof kernel sigset_t
break __BREAK_SYSCALL
flushrs // save dirty partition on rbs
mov.m rFPSR = ar.fpsr
mov.m rRSC = ar.rsc
add r2 = SC_GR+1*8, r32
;;
mov.m rBSP = ar.bsp
.save ar.unat, rUNAT
mov.m rUNAT = ar.unat
.body
add r3 = SC_GR+4*8, r32
;;
.mem.offset 0,0; st8.spill [r2] = r1, (5*8 - 1*8)
.mem.offset 8,0; st8.spill [r3] = r4, 16
mov.i rPFS = ar.pfs
;;
.mem.offset 0,0; st8.spill [r2] = r5, 16
.mem.offset 8,0; st8.spill [r3] = r6, 48
and rTMP = ~0x3, rRSC
;;
.mem.offset 0,0; st8.spill [r2] = r7, (SC_FR+2*16-(SC_GR+7*8))
.mem.offset 8,0; st8.spill [r3] = sp, (SC_FR+3*16-(SC_GR+12*8))
;;
mov.m ar.rsc = rTMP // put RSE into enforced lazy mode
mov.m rNAT = ar.unat
mov.i rLC = ar.lc
;;
mov.m rRNAT = ar.rnat
mov.m ar.rsc = rRSC // restore RSE mode
mov rPR = pr
/*
* Rotate NaT bits by rPOS positions to the right:
*/
stf.spill [r2] = f2, 32
stf.spill [r3] = f3, 32
add rPOS = SC_GR, r32 // rPOS <- &sc_gr[0]
;;
stf.spill [r2] = f4, (16*16-4*16)
stf.spill [r3] = f5, (17*16-5*16)
extr.u rPOS = rPOS, 3, 6 // get NaT bit number for r0
;;
stf.spill [r2] = f16, 32
stf.spill [r3] = f17, 32
sub rCPOS = 64, rPOS
;;
stf.spill [r2] = f18, 32
stf.spill [r3] = f19, 32
shr.u rTMP = rNAT, rPOS
;;
stf.spill [r2] = f20, 32
stf.spill [r3] = f21, 32
shl rNAT = rNAT, rCPOS
;;
stf.spill [r2] = f22, 32
stf.spill [r3] = f23, 32
or rNAT = rNAT, rTMP
;;
stf.spill [r2] = f24, 32
stf.spill [r3] = f25, 32
mov r8 = 0
;;
stf.spill [r2] = f26, 32
stf.spill [r3] = f27, 32
mov r9 = 1
;;
stf.spill [r2] = f28, 32
stf.spill [r3] = f29, 32
mov rB0 = b0
;;
stf.spill [r2] = f30, 32
stf.spill [r3] = f31, 32
mov rB1 = b1
;;
mov ar.unat = rUNAT // we're done spilling integer regs; restore caller's UNaT
add r2 = SC_NAT, r32
add r3 = SC_BSP, r32
;;
st8 [r2] = rNAT, (SC_RNAT-SC_NAT)
st8 [r3] = rBSP, (SC_UNAT-SC_BSP)
mov rB2 = b2
;;
st8 [r2] = rRNAT, (SC_FPSR-SC_RNAT)
st8 [r3] = rUNAT, (SC_PFS-SC_UNAT)
mov rB3 = b3
;;
st8 [r2] = rFPSR, (SC_LC-SC_FPSR)
st8 [r3] = rPFS, (SC_PR-SC_PFS)
mov rB4 = b4
;;
st8 [r2] = rLC, (SC_BR+0*8-SC_LC)
st8 [r3] = rPR, (SC_BR+1*8-SC_PR)
mov rB5 = b5
;;
st8 [r2] = rB0, 16
st8 [r3] = rB1, 16
;;
st8 [r2] = rB2, 16
st8 [r3] = rB3, 16
;;
st8 [r2] = rB4
st8 [r3] = rB5
ret
END(__getcontext)
weak_alias(__getcontext, getcontext)
|
