1 /* Copyright (C) 2001-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
21 #include "ucontext_i.h"
23 /* __getcontext (ucontext_t *ucp)
25 Saves the machine context in UCP such that when it is activated,
26 it appears as if __getcontext() returned again. The only difference
27 is that on a first return, r9 contains 1 and on a subsequent
28 return, it contains 0.
30 This implementation in intended to be used for *synchronous* context
31 switches only. Therefore, it does not have to save anything
32 other than the PRESERVED state. */
37 alloc r11 = ar.pfs, 1, 0, 4, 0
39 // sigprocmask (SIG_BLOCK, NULL, &sc->sc_mask):
44 flushrs // save dirty partition on rbs
48 mov out3 = 8 // sizeof kernel sigset_t
49 DO_CALL(__NR_rt_sigprocmask)
53 add r2 = SC_GR+1*8, r32
60 add r3 = SC_GR+4*8, r32
63 .mem.offset 0,0; st8.spill [r2] = r1, (5*8 - 1*8)
64 .mem.offset 8,0; st8.spill [r3] = r4, 16
67 .mem.offset 0,0; st8.spill [r2] = r5, 16
68 .mem.offset 8,0; st8.spill [r3] = r6, 48
71 .mem.offset 0,0; st8.spill [r2] = r7, (SC_FR+2*16-(SC_GR+7*8))
72 .mem.offset 8,0; st8.spill [r3] = sp, (SC_FR+3*16-(SC_GR+12*8))
74 mov.m ar.rsc = rTMP // put RSE into enforced lazy mode
79 mov.m ar.rsc = rRSC // restore RSE mode
83 * Rotate NaT bits by rPOS positions to the right:
85 stf.spill [r2] = f2, 32
86 stf.spill [r3] = f3, 32
87 add rPOS = SC_GR, r32 // rPOS <- &sc_gr[0]
89 stf.spill [r2] = f4, (16*16-4*16)
90 stf.spill [r3] = f5, (17*16-5*16)
91 extr.u rPOS = rPOS, 3, 6 // get NaT bit number for r0
93 stf.spill [r2] = f16, 32
94 stf.spill [r3] = f17, 32
97 stf.spill [r2] = f18, 32
98 stf.spill [r3] = f19, 32
99 shr.u rTMP = rNAT, rPOS
101 stf.spill [r2] = f20, 32
102 stf.spill [r3] = f21, 32
103 shl rNAT = rNAT, rCPOS
105 stf.spill [r2] = f22, 32
106 stf.spill [r3] = f23, 32
109 stf.spill [r2] = f24, 32
110 stf.spill [r3] = f25, 32
113 stf.spill [r2] = f26, 32
114 stf.spill [r3] = f27, 32
117 stf.spill [r2] = f28, 32
118 stf.spill [r3] = f29, 32
121 stf.spill [r2] = f30, 32
122 stf.spill [r3] = f31, 32
125 mov ar.unat = rUNAT // we're done spilling integer regs; restore caller's UNaT
129 st8 [r2] = rNAT, (SC_RNAT-SC_NAT)
130 st8 [r3] = rBSP, (SC_UNAT-SC_BSP)
133 st8 [r2] = rRNAT, (SC_FPSR-SC_RNAT)
134 st8 [r3] = rUNAT, (SC_PFS-SC_UNAT)
137 st8 [r2] = rFPSR, (SC_LC-SC_FPSR)
138 st8 [r3] = rPFS, (SC_PR-SC_PFS)
141 st8 [r2] = rLC, (SC_BR+0*8-SC_LC)
142 st8 [r3] = rPR, (SC_BR+1*8-SC_PR)
156 weak_alias (__getcontext, getcontext)