xref: /openbmc/qemu/linux-user/sparc/target_cpu.h (revision 6c7937ec)
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 void set_syscall_C(CPUSPARCState *env, bool val)
30 {
31 #ifndef TARGET_SPARC64
32     env->icc_C = val;
33 #elif defined(TARGET_ABI32)
34     env->icc_C = (uint64_t)val << 32;
35 #else
36     env->xcc_C = val;
37 #endif
38 }
39 
40 static inline void cpu_clone_regs_child(CPUSPARCState *env, target_ulong newsp,
41                                         unsigned flags)
42 {
43     /*
44      * After cpu_copy, env->regwptr is pointing into the old env.
45      * Update the new cpu to use its own register window.
46      */
47     env->regwptr = env->regbase + (env->cwp * 16);
48 
49     if (newsp) {
50         /* When changing stacks, do it with clean register windows.  */
51 #ifdef TARGET_SPARC64
52         env->cansave = env->nwindows - 2;
53         env->cleanwin = env->nwindows - 2;
54         env->canrestore = 0;
55 #else
56         env->wim = 1 << env->cwp;
57 #endif
58         /* ??? The kernel appears to copy one stack frame to the new stack. */
59         /* ??? The kernel force aligns the new stack. */
60         /* Userspace provides a biased stack pointer value. */
61         env->regwptr[WREG_SP] = newsp;
62     }
63 
64     if (flags & CLONE_VM) {
65         /*
66          * Syscall return for clone child: %o0 = 0 and clear CF since this
67          * counts as a success return value.  Advance the PC past the syscall.
68          * For fork child, all of this happens in cpu_loop, and we must not
69          * do the pc advance twice.
70          */
71         env->regwptr[WREG_O0] = 0;
72         set_syscall_C(env, 0);
73         env->pc = env->npc;
74         env->npc = env->npc + 4;
75     }
76 
77     /* Set the second return value for the child: %o1 = 1.  */
78     env->regwptr[WREG_O1] = 1;
79 }
80 
81 static inline void cpu_clone_regs_parent(CPUSPARCState *env, unsigned flags)
82 {
83     /* Set the second return value for the parent: %o1 = 0.  */
84     env->regwptr[WREG_O1] = 0;
85 }
86 
87 static inline void cpu_set_tls(CPUSPARCState *env, target_ulong newtls)
88 {
89     env->gregs[7] = newtls;
90 }
91 
92 static inline abi_ulong get_sp_from_cpustate(CPUSPARCState *state)
93 {
94     return state->regwptr[WREG_SP] + TARGET_STACK_BIAS;
95 }
96 
97 #endif
98