xref: /openbmc/qemu/linux-user/sparc/cpu_loop.c (revision a81df1b6)
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 "cpu_loop-common.h"
24 
25 #define SPARC64_STACK_BIAS 2047
26 
27 //#define DEBUG_WIN
28 
29 /* WARNING: dealing with register windows _is_ complicated. More info
30    can be found at http://www.sics.se/~psm/sparcstack.html */
31 static inline int get_reg_index(CPUSPARCState *env, int cwp, int index)
32 {
33     index = (index + cwp * 16) % (16 * env->nwindows);
34     /* wrap handling : if cwp is on the last window, then we use the
35        registers 'after' the end */
36     if (index < 8 && env->cwp == env->nwindows - 1)
37         index += 16 * env->nwindows;
38     return index;
39 }
40 
41 /* save the register window 'cwp1' */
42 static inline void save_window_offset(CPUSPARCState *env, int cwp1)
43 {
44     unsigned int i;
45     abi_ulong sp_ptr;
46 
47     sp_ptr = env->regbase[get_reg_index(env, cwp1, 6)];
48 #ifdef TARGET_SPARC64
49     if (sp_ptr & 3)
50         sp_ptr += SPARC64_STACK_BIAS;
51 #endif
52 #if defined(DEBUG_WIN)
53     printf("win_overflow: sp_ptr=0x" TARGET_ABI_FMT_lx " save_cwp=%d\n",
54            sp_ptr, cwp1);
55 #endif
56     for(i = 0; i < 16; i++) {
57         /* FIXME - what to do if put_user() fails? */
58         put_user_ual(env->regbase[get_reg_index(env, cwp1, 8 + i)], sp_ptr);
59         sp_ptr += sizeof(abi_ulong);
60     }
61 }
62 
63 static void save_window(CPUSPARCState *env)
64 {
65 #ifndef TARGET_SPARC64
66     unsigned int new_wim;
67     new_wim = ((env->wim >> 1) | (env->wim << (env->nwindows - 1))) &
68         ((1LL << env->nwindows) - 1);
69     save_window_offset(env, cpu_cwp_dec(env, env->cwp - 2));
70     env->wim = new_wim;
71 #else
72     /*
73      * cansave is zero if the spill trap handler is triggered by `save` and
74      * nonzero if triggered by a `flushw`
75      */
76     save_window_offset(env, cpu_cwp_dec(env, env->cwp - env->cansave - 2));
77     env->cansave++;
78     env->canrestore--;
79 #endif
80 }
81 
82 static void restore_window(CPUSPARCState *env)
83 {
84 #ifndef TARGET_SPARC64
85     unsigned int new_wim;
86 #endif
87     unsigned int i, cwp1;
88     abi_ulong sp_ptr;
89 
90 #ifndef TARGET_SPARC64
91     new_wim = ((env->wim << 1) | (env->wim >> (env->nwindows - 1))) &
92         ((1LL << env->nwindows) - 1);
93 #endif
94 
95     /* restore the invalid window */
96     cwp1 = cpu_cwp_inc(env, env->cwp + 1);
97     sp_ptr = env->regbase[get_reg_index(env, cwp1, 6)];
98 #ifdef TARGET_SPARC64
99     if (sp_ptr & 3)
100         sp_ptr += SPARC64_STACK_BIAS;
101 #endif
102 #if defined(DEBUG_WIN)
103     printf("win_underflow: sp_ptr=0x" TARGET_ABI_FMT_lx " load_cwp=%d\n",
104            sp_ptr, cwp1);
105 #endif
106     for(i = 0; i < 16; i++) {
107         /* FIXME - what to do if get_user() fails? */
108         get_user_ual(env->regbase[get_reg_index(env, cwp1, 8 + i)], sp_ptr);
109         sp_ptr += sizeof(abi_ulong);
110     }
111 #ifdef TARGET_SPARC64
112     env->canrestore++;
113     if (env->cleanwin < env->nwindows - 1)
114         env->cleanwin++;
115     env->cansave--;
116 #else
117     env->wim = new_wim;
118 #endif
119 }
120 
121 static void flush_windows(CPUSPARCState *env)
122 {
123     int offset, cwp1;
124 
125     offset = 1;
126     for(;;) {
127         /* if restore would invoke restore_window(), then we can stop */
128         cwp1 = cpu_cwp_inc(env, env->cwp + offset);
129 #ifndef TARGET_SPARC64
130         if (env->wim & (1 << cwp1))
131             break;
132 #else
133         if (env->canrestore == 0)
134             break;
135         env->cansave++;
136         env->canrestore--;
137 #endif
138         save_window_offset(env, cwp1);
139         offset++;
140     }
141     cwp1 = cpu_cwp_inc(env, env->cwp + 1);
142 #ifndef TARGET_SPARC64
143     /* set wim so that restore will reload the registers */
144     env->wim = 1 << cwp1;
145 #endif
146 #if defined(DEBUG_WIN)
147     printf("flush_windows: nb=%d\n", offset - 1);
148 #endif
149 }
150 
151 void cpu_loop (CPUSPARCState *env)
152 {
153     CPUState *cs = env_cpu(env);
154     int trapnr;
155     abi_long ret;
156     target_siginfo_t info;
157 
158     while (1) {
159         cpu_exec_start(cs);
160         trapnr = cpu_exec(cs);
161         cpu_exec_end(cs);
162         process_queued_cpu_work(cs);
163 
164         /* Compute PSR before exposing state.  */
165         if (env->cc_op != CC_OP_FLAGS) {
166             cpu_get_psr(env);
167         }
168 
169         switch (trapnr) {
170 #ifndef TARGET_SPARC64
171         case 0x88:
172         case 0x90:
173 #else
174         case 0x110:
175         case 0x16d:
176 #endif
177             ret = do_syscall (env, env->gregs[1],
178                               env->regwptr[0], env->regwptr[1],
179                               env->regwptr[2], env->regwptr[3],
180                               env->regwptr[4], env->regwptr[5],
181                               0, 0);
182             if (ret == -TARGET_ERESTARTSYS || ret == -TARGET_QEMU_ESIGRETURN) {
183                 break;
184             }
185             if ((abi_ulong)ret >= (abi_ulong)(-515)) {
186 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
187                 env->xcc |= PSR_CARRY;
188 #else
189                 env->psr |= PSR_CARRY;
190 #endif
191                 ret = -ret;
192             } else {
193 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
194                 env->xcc &= ~PSR_CARRY;
195 #else
196                 env->psr &= ~PSR_CARRY;
197 #endif
198             }
199             env->regwptr[0] = ret;
200             /* next instruction */
201             env->pc = env->npc;
202             env->npc = env->npc + 4;
203             break;
204         case 0x83: /* flush windows */
205 #ifdef TARGET_ABI32
206         case 0x103:
207 #endif
208             flush_windows(env);
209             /* next instruction */
210             env->pc = env->npc;
211             env->npc = env->npc + 4;
212             break;
213 #ifndef TARGET_SPARC64
214         case TT_WIN_OVF: /* window overflow */
215             save_window(env);
216             break;
217         case TT_WIN_UNF: /* window underflow */
218             restore_window(env);
219             break;
220         case TT_TFAULT:
221         case TT_DFAULT:
222             {
223                 info.si_signo = TARGET_SIGSEGV;
224                 info.si_errno = 0;
225                 /* XXX: check env->error_code */
226                 info.si_code = TARGET_SEGV_MAPERR;
227                 info._sifields._sigfault._addr = env->mmuregs[4];
228                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
229             }
230             break;
231 #else
232         case TT_SPILL: /* window overflow */
233             save_window(env);
234             break;
235         case TT_FILL: /* window underflow */
236             restore_window(env);
237             break;
238         case TT_TFAULT:
239         case TT_DFAULT:
240             {
241                 info.si_signo = TARGET_SIGSEGV;
242                 info.si_errno = 0;
243                 /* XXX: check env->error_code */
244                 info.si_code = TARGET_SEGV_MAPERR;
245                 if (trapnr == TT_DFAULT)
246                     info._sifields._sigfault._addr = env->dmmu.mmuregs[4];
247                 else
248                     info._sifields._sigfault._addr = cpu_tsptr(env)->tpc;
249                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
250             }
251             break;
252 #ifndef TARGET_ABI32
253         case 0x16e:
254             flush_windows(env);
255             sparc64_get_context(env);
256             break;
257         case 0x16f:
258             flush_windows(env);
259             sparc64_set_context(env);
260             break;
261 #endif
262 #endif
263         case EXCP_INTERRUPT:
264             /* just indicate that signals should be handled asap */
265             break;
266         case TT_ILL_INSN:
267             {
268                 info.si_signo = TARGET_SIGILL;
269                 info.si_errno = 0;
270                 info.si_code = TARGET_ILL_ILLOPC;
271                 info._sifields._sigfault._addr = env->pc;
272                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
273             }
274             break;
275         case EXCP_DEBUG:
276             info.si_signo = TARGET_SIGTRAP;
277             info.si_errno = 0;
278             info.si_code = TARGET_TRAP_BRKPT;
279             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
280             break;
281         case EXCP_ATOMIC:
282             cpu_exec_step_atomic(cs);
283             break;
284         default:
285             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
286             cpu_dump_state(cs, stderr, 0);
287             exit(EXIT_FAILURE);
288         }
289         process_pending_signals (env);
290     }
291 }
292 
293 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
294 {
295     int i;
296     env->pc = regs->pc;
297     env->npc = regs->npc;
298     env->y = regs->y;
299     for(i = 0; i < 8; i++)
300         env->gregs[i] = regs->u_regs[i];
301     for(i = 0; i < 8; i++)
302         env->regwptr[i] = regs->u_regs[i + 8];
303 }
304