xref: /openbmc/qemu/linux-user/sparc/target_cpu.h (revision ddda3748)
1 /*
2  * SPARC specific CPU ABI and functions for linux-user
3  *
4  * Copyright (C) 2003 Thomas M. Ogrisegg <tom@fnord.at>
5  * Copyright (C) 2003-2005 Fabrice Bellard
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19  */
20 #ifndef SPARC_TARGET_CPU_H
21 #define SPARC_TARGET_CPU_H
22 
23 static inline void cpu_clone_regs_child(CPUSPARCState *env, target_ulong newsp,
24                                         unsigned flags)
25 {
26     /*
27      * After cpu_copy, env->regwptr is pointing into the old env.
28      * Update the new cpu to use its own register window.
29      */
30     env->regwptr = env->regbase + (env->cwp * 16);
31 
32     if (newsp) {
33         /* When changing stacks, do it with clean register windows.  */
34 #ifdef TARGET_SPARC64
35         env->cansave = env->nwindows - 2;
36         env->cleanwin = env->nwindows - 2;
37         env->canrestore = 0;
38 #else
39         env->wim = 1 << env->cwp;
40 #endif
41         /* ??? The kernel appears to copy one stack frame to the new stack. */
42         /* ??? The kernel force aligns the new stack. */
43         env->regwptr[WREG_SP] = newsp;
44     }
45 
46     if (flags & CLONE_VM) {
47         /*
48          * Syscall return for clone child: %o0 = 0 and clear CF since this
49          * counts as a success return value.  Advance the PC past the syscall.
50          * For fork child, all of this happens in cpu_loop, and we must not
51          * do the pc advance twice.
52          */
53         env->regwptr[WREG_O0] = 0;
54 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
55         env->xcc &= ~PSR_CARRY;
56 #else
57         env->psr &= ~PSR_CARRY;
58 #endif
59         env->pc = env->npc;
60         env->npc = env->npc + 4;
61     }
62 
63     /* Set the second return value for the child: %o1 = 1.  */
64     env->regwptr[WREG_O1] = 1;
65 }
66 
67 static inline void cpu_clone_regs_parent(CPUSPARCState *env, unsigned flags)
68 {
69     /* Set the second return value for the parent: %o1 = 0.  */
70     env->regwptr[WREG_O1] = 0;
71 }
72 
73 static inline void cpu_set_tls(CPUSPARCState *env, target_ulong newtls)
74 {
75     env->gregs[7] = newtls;
76 }
77 
78 static inline abi_ulong get_sp_from_cpustate(CPUSPARCState *state)
79 {
80     return state->regwptr[WREG_SP];
81 }
82 
83 #endif
84