xref: /openbmc/qemu/linux-user/sparc/cpu_loop.c (revision 0fbb5d2d)
1 /*
2  *  qemu user cpu loop
3  *
4  *  Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qemu-common.h"
22 #include "qemu.h"
23 #include "user-internals.h"
24 #include "cpu_loop-common.h"
25 #include "signal-common.h"
26 
27 #define SPARC64_STACK_BIAS 2047
28 
29 //#define DEBUG_WIN
30 
31 /* WARNING: dealing with register windows _is_ complicated. More info
32    can be found at http://www.sics.se/~psm/sparcstack.html */
33 static inline int get_reg_index(CPUSPARCState *env, int cwp, int index)
34 {
35     index = (index + cwp * 16) % (16 * env->nwindows);
36     /* wrap handling : if cwp is on the last window, then we use the
37        registers 'after' the end */
38     if (index < 8 && env->cwp == env->nwindows - 1)
39         index += 16 * env->nwindows;
40     return index;
41 }
42 
43 /* save the register window 'cwp1' */
44 static inline void save_window_offset(CPUSPARCState *env, int cwp1)
45 {
46     unsigned int i;
47     abi_ulong sp_ptr;
48 
49     sp_ptr = env->regbase[get_reg_index(env, cwp1, 6)];
50 #ifdef TARGET_SPARC64
51     if (sp_ptr & 3)
52         sp_ptr += SPARC64_STACK_BIAS;
53 #endif
54 #if defined(DEBUG_WIN)
55     printf("win_overflow: sp_ptr=0x" TARGET_ABI_FMT_lx " save_cwp=%d\n",
56            sp_ptr, cwp1);
57 #endif
58     for(i = 0; i < 16; i++) {
59         /* FIXME - what to do if put_user() fails? */
60         put_user_ual(env->regbase[get_reg_index(env, cwp1, 8 + i)], sp_ptr);
61         sp_ptr += sizeof(abi_ulong);
62     }
63 }
64 
65 static void save_window(CPUSPARCState *env)
66 {
67 #ifndef TARGET_SPARC64
68     unsigned int new_wim;
69     new_wim = ((env->wim >> 1) | (env->wim << (env->nwindows - 1))) &
70         ((1LL << env->nwindows) - 1);
71     save_window_offset(env, cpu_cwp_dec(env, env->cwp - 2));
72     env->wim = new_wim;
73 #else
74     /*
75      * cansave is zero if the spill trap handler is triggered by `save` and
76      * nonzero if triggered by a `flushw`
77      */
78     save_window_offset(env, cpu_cwp_dec(env, env->cwp - env->cansave - 2));
79     env->cansave++;
80     env->canrestore--;
81 #endif
82 }
83 
84 static void restore_window(CPUSPARCState *env)
85 {
86 #ifndef TARGET_SPARC64
87     unsigned int new_wim;
88 #endif
89     unsigned int i, cwp1;
90     abi_ulong sp_ptr;
91 
92 #ifndef TARGET_SPARC64
93     new_wim = ((env->wim << 1) | (env->wim >> (env->nwindows - 1))) &
94         ((1LL << env->nwindows) - 1);
95 #endif
96 
97     /* restore the invalid window */
98     cwp1 = cpu_cwp_inc(env, env->cwp + 1);
99     sp_ptr = env->regbase[get_reg_index(env, cwp1, 6)];
100 #ifdef TARGET_SPARC64
101     if (sp_ptr & 3)
102         sp_ptr += SPARC64_STACK_BIAS;
103 #endif
104 #if defined(DEBUG_WIN)
105     printf("win_underflow: sp_ptr=0x" TARGET_ABI_FMT_lx " load_cwp=%d\n",
106            sp_ptr, cwp1);
107 #endif
108     for(i = 0; i < 16; i++) {
109         /* FIXME - what to do if get_user() fails? */
110         get_user_ual(env->regbase[get_reg_index(env, cwp1, 8 + i)], sp_ptr);
111         sp_ptr += sizeof(abi_ulong);
112     }
113 #ifdef TARGET_SPARC64
114     env->canrestore++;
115     if (env->cleanwin < env->nwindows - 1)
116         env->cleanwin++;
117     env->cansave--;
118 #else
119     env->wim = new_wim;
120 #endif
121 }
122 
123 static void flush_windows(CPUSPARCState *env)
124 {
125     int offset, cwp1;
126 
127     offset = 1;
128     for(;;) {
129         /* if restore would invoke restore_window(), then we can stop */
130         cwp1 = cpu_cwp_inc(env, env->cwp + offset);
131 #ifndef TARGET_SPARC64
132         if (env->wim & (1 << cwp1))
133             break;
134 #else
135         if (env->canrestore == 0)
136             break;
137         env->cansave++;
138         env->canrestore--;
139 #endif
140         save_window_offset(env, cwp1);
141         offset++;
142     }
143     cwp1 = cpu_cwp_inc(env, env->cwp + 1);
144 #ifndef TARGET_SPARC64
145     /* set wim so that restore will reload the registers */
146     env->wim = 1 << cwp1;
147 #endif
148 #if defined(DEBUG_WIN)
149     printf("flush_windows: nb=%d\n", offset - 1);
150 #endif
151 }
152 
153 void cpu_loop (CPUSPARCState *env)
154 {
155     CPUState *cs = env_cpu(env);
156     int trapnr;
157     abi_long ret;
158     target_siginfo_t info;
159 
160     while (1) {
161         cpu_exec_start(cs);
162         trapnr = cpu_exec(cs);
163         cpu_exec_end(cs);
164         process_queued_cpu_work(cs);
165 
166         /* Compute PSR before exposing state.  */
167         if (env->cc_op != CC_OP_FLAGS) {
168             cpu_get_psr(env);
169         }
170 
171         switch (trapnr) {
172 #ifndef TARGET_SPARC64
173         case 0x88:
174         case 0x90:
175 #else
176         case 0x110:
177         case 0x16d:
178 #endif
179             ret = do_syscall (env, env->gregs[1],
180                               env->regwptr[0], env->regwptr[1],
181                               env->regwptr[2], env->regwptr[3],
182                               env->regwptr[4], env->regwptr[5],
183                               0, 0);
184             if (ret == -QEMU_ERESTARTSYS || ret == -QEMU_ESIGRETURN) {
185                 break;
186             }
187             if ((abi_ulong)ret >= (abi_ulong)(-515)) {
188 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
189                 env->xcc |= PSR_CARRY;
190 #else
191                 env->psr |= PSR_CARRY;
192 #endif
193                 ret = -ret;
194             } else {
195 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
196                 env->xcc &= ~PSR_CARRY;
197 #else
198                 env->psr &= ~PSR_CARRY;
199 #endif
200             }
201             env->regwptr[0] = ret;
202             /* next instruction */
203             env->pc = env->npc;
204             env->npc = env->npc + 4;
205             break;
206         case 0x83: /* flush windows */
207 #ifdef TARGET_ABI32
208         case 0x103:
209 #endif
210             flush_windows(env);
211             /* next instruction */
212             env->pc = env->npc;
213             env->npc = env->npc + 4;
214             break;
215 #ifndef TARGET_SPARC64
216         case TT_WIN_OVF: /* window overflow */
217             save_window(env);
218             break;
219         case TT_WIN_UNF: /* window underflow */
220             restore_window(env);
221             break;
222 #else
223         case TT_SPILL: /* window overflow */
224             save_window(env);
225             break;
226         case TT_FILL: /* window underflow */
227             restore_window(env);
228             break;
229 #ifndef TARGET_ABI32
230         case 0x16e:
231             flush_windows(env);
232             sparc64_get_context(env);
233             break;
234         case 0x16f:
235             flush_windows(env);
236             sparc64_set_context(env);
237             break;
238 #endif
239 #endif
240         case EXCP_INTERRUPT:
241             /* just indicate that signals should be handled asap */
242             break;
243         case TT_ILL_INSN:
244             {
245                 info.si_signo = TARGET_SIGILL;
246                 info.si_errno = 0;
247                 info.si_code = TARGET_ILL_ILLOPC;
248                 info._sifields._sigfault._addr = env->pc;
249                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
250             }
251             break;
252         case EXCP_DEBUG:
253             info.si_signo = TARGET_SIGTRAP;
254             info.si_errno = 0;
255             info.si_code = TARGET_TRAP_BRKPT;
256             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
257             break;
258         case EXCP_ATOMIC:
259             cpu_exec_step_atomic(cs);
260             break;
261         default:
262             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
263             cpu_dump_state(cs, stderr, 0);
264             exit(EXIT_FAILURE);
265         }
266         process_pending_signals (env);
267     }
268 }
269 
270 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
271 {
272     int i;
273     env->pc = regs->pc;
274     env->npc = regs->npc;
275     env->y = regs->y;
276     for(i = 0; i < 8; i++)
277         env->gregs[i] = regs->u_regs[i];
278     for(i = 0; i < 8; i++)
279         env->regwptr[i] = regs->u_regs[i + 8];
280 }
281