xref: /openbmc/qemu/linux-user/sparc/target_cpu.h (revision ffe98631)
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 2.1 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 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
24 # define TARGET_STACK_BIAS 2047
25 #else
26 # define TARGET_STACK_BIAS 0
27 #endif
28 
29 static inline void cpu_clone_regs_child(CPUSPARCState *env, target_ulong newsp,
30                                         unsigned flags)
31 {
32     /*
33      * After cpu_copy, env->regwptr is pointing into the old env.
34      * Update the new cpu to use its own register window.
35      */
36     env->regwptr = env->regbase + (env->cwp * 16);
37 
38     if (newsp) {
39         /* When changing stacks, do it with clean register windows.  */
40 #ifdef TARGET_SPARC64
41         env->cansave = env->nwindows - 2;
42         env->cleanwin = env->nwindows - 2;
43         env->canrestore = 0;
44 #else
45         env->wim = 1 << env->cwp;
46 #endif
47         /* ??? The kernel appears to copy one stack frame to the new stack. */
48         /* ??? The kernel force aligns the new stack. */
49         /* Userspace provides a biased stack pointer value. */
50         env->regwptr[WREG_SP] = newsp;
51     }
52 
53     if (flags & CLONE_VM) {
54         /*
55          * Syscall return for clone child: %o0 = 0 and clear CF since this
56          * counts as a success return value.  Advance the PC past the syscall.
57          * For fork child, all of this happens in cpu_loop, and we must not
58          * do the pc advance twice.
59          */
60         env->regwptr[WREG_O0] = 0;
61 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
62         env->xcc &= ~PSR_CARRY;
63 #else
64         env->psr &= ~PSR_CARRY;
65 #endif
66         env->pc = env->npc;
67         env->npc = env->npc + 4;
68     }
69 
70     /* Set the second return value for the child: %o1 = 1.  */
71     env->regwptr[WREG_O1] = 1;
72 }
73 
74 static inline void cpu_clone_regs_parent(CPUSPARCState *env, unsigned flags)
75 {
76     /* Set the second return value for the parent: %o1 = 0.  */
77     env->regwptr[WREG_O1] = 0;
78 }
79 
80 static inline void cpu_set_tls(CPUSPARCState *env, target_ulong newtls)
81 {
82     env->gregs[7] = newtls;
83 }
84 
85 static inline abi_ulong get_sp_from_cpustate(CPUSPARCState *state)
86 {
87     return state->regwptr[WREG_SP] + TARGET_STACK_BIAS;
88 }
89 
90 #endif
91