xref: /qemu/linux-user/sparc/cpu_loop.c (revision d6b036378004c27579aa68bf0174e4e8fbfff726)
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.h"
22 #include "user-internals.h"
23 #include "cpu_loop-common.h"
24 #include "signal-common.h"
25 
26 #define SPARC64_STACK_BIAS 2047
27 
28 //#define DEBUG_WIN
29 
30 /* WARNING: dealing with register windows _is_ complicated. More info
31    can be found at http://www.sics.se/~psm/sparcstack.html */
32 static inline int get_reg_index(CPUSPARCState *env, int cwp, int index)
33 {
34     index = (index + cwp * 16) % (16 * env->nwindows);
35     /* wrap handling : if cwp is on the last window, then we use the
36        registers 'after' the end */
37     if (index < 8 && env->cwp == env->nwindows - 1)
38         index += 16 * env->nwindows;
39     return index;
40 }
41 
42 /* save the register window 'cwp1' */
43 static inline void save_window_offset(CPUSPARCState *env, int cwp1)
44 {
45     unsigned int i;
46     abi_ulong sp_ptr;
47 
48     sp_ptr = env->regbase[get_reg_index(env, cwp1, 6)];
49 #ifdef TARGET_SPARC64
50     if (sp_ptr & 3)
51         sp_ptr += SPARC64_STACK_BIAS;
52 #endif
53 #if defined(DEBUG_WIN)
54     printf("win_overflow: sp_ptr=0x" TARGET_ABI_FMT_lx " save_cwp=%d\n",
55            sp_ptr, cwp1);
56 #endif
57     for(i = 0; i < 16; i++) {
58         /* FIXME - what to do if put_user() fails? */
59         put_user_ual(env->regbase[get_reg_index(env, cwp1, 8 + i)], sp_ptr);
60         sp_ptr += sizeof(abi_ulong);
61     }
62 }
63 
64 static void save_window(CPUSPARCState *env)
65 {
66 #ifndef TARGET_SPARC64
67     unsigned int new_wim;
68     new_wim = ((env->wim >> 1) | (env->wim << (env->nwindows - 1))) &
69         ((1LL << env->nwindows) - 1);
70     save_window_offset(env, cpu_cwp_dec(env, env->cwp - 2));
71     env->wim = new_wim;
72 #else
73     /*
74      * cansave is zero if the spill trap handler is triggered by `save` and
75      * nonzero if triggered by a `flushw`
76      */
77     save_window_offset(env, cpu_cwp_dec(env, env->cwp - env->cansave - 2));
78     env->cansave++;
79     env->canrestore--;
80 #endif
81 }
82 
83 static void restore_window(CPUSPARCState *env)
84 {
85 #ifndef TARGET_SPARC64
86     unsigned int new_wim;
87 #endif
88     unsigned int i, cwp1;
89     abi_ulong sp_ptr;
90 
91 #ifndef TARGET_SPARC64
92     new_wim = ((env->wim << 1) | (env->wim >> (env->nwindows - 1))) &
93         ((1LL << env->nwindows) - 1);
94 #endif
95 
96     /* restore the invalid window */
97     cwp1 = cpu_cwp_inc(env, env->cwp + 1);
98     sp_ptr = env->regbase[get_reg_index(env, cwp1, 6)];
99 #ifdef TARGET_SPARC64
100     if (sp_ptr & 3)
101         sp_ptr += SPARC64_STACK_BIAS;
102 #endif
103 #if defined(DEBUG_WIN)
104     printf("win_underflow: sp_ptr=0x" TARGET_ABI_FMT_lx " load_cwp=%d\n",
105            sp_ptr, cwp1);
106 #endif
107     for(i = 0; i < 16; i++) {
108         /* FIXME - what to do if get_user() fails? */
109         get_user_ual(env->regbase[get_reg_index(env, cwp1, 8 + i)], sp_ptr);
110         sp_ptr += sizeof(abi_ulong);
111     }
112 #ifdef TARGET_SPARC64
113     env->canrestore++;
114     if (env->cleanwin < env->nwindows - 1)
115         env->cleanwin++;
116     env->cansave--;
117 #else
118     env->wim = new_wim;
119 #endif
120 }
121 
122 static void flush_windows(CPUSPARCState *env)
123 {
124     int offset, cwp1;
125 
126     offset = 1;
127     for(;;) {
128         /* if restore would invoke restore_window(), then we can stop */
129         cwp1 = cpu_cwp_inc(env, env->cwp + offset);
130 #ifndef TARGET_SPARC64
131         if (env->wim & (1 << cwp1))
132             break;
133 #else
134         if (env->canrestore == 0)
135             break;
136         env->cansave++;
137         env->canrestore--;
138 #endif
139         save_window_offset(env, cwp1);
140         offset++;
141     }
142     cwp1 = cpu_cwp_inc(env, env->cwp + 1);
143 #ifndef TARGET_SPARC64
144     /* set wim so that restore will reload the registers */
145     env->wim = 1 << cwp1;
146 #endif
147 #if defined(DEBUG_WIN)
148     printf("flush_windows: nb=%d\n", offset - 1);
149 #endif
150 }
151 
152 /* Avoid ifdefs below for the abi32 and abi64 paths. */
153 #ifdef TARGET_ABI32
154 #define TARGET_TT_SYSCALL  (TT_TRAP + 0x10) /* t_linux */
155 #define syscall_cc         psr
156 #else
157 #define TARGET_TT_SYSCALL  (TT_TRAP + 0x6d) /* tl0_linux64 */
158 #define syscall_cc         xcc
159 #endif
160 
161 /* Avoid ifdefs below for the v9 and pre-v9 hw traps. */
162 #ifdef TARGET_SPARC64
163 #define TARGET_TT_SPILL  TT_SPILL
164 #define TARGET_TT_FILL   TT_FILL
165 #else
166 #define TARGET_TT_SPILL  TT_WIN_OVF
167 #define TARGET_TT_FILL   TT_WIN_UNF
168 #endif
169 
170 void cpu_loop (CPUSPARCState *env)
171 {
172     CPUState *cs = env_cpu(env);
173     int trapnr;
174     abi_long ret;
175 
176     while (1) {
177         cpu_exec_start(cs);
178         trapnr = cpu_exec(cs);
179         cpu_exec_end(cs);
180         process_queued_cpu_work(cs);
181 
182         /* Compute PSR before exposing state.  */
183         if (env->cc_op != CC_OP_FLAGS) {
184             cpu_get_psr(env);
185         }
186 
187         switch (trapnr) {
188         case TARGET_TT_SYSCALL:
189             ret = do_syscall (env, env->gregs[1],
190                               env->regwptr[0], env->regwptr[1],
191                               env->regwptr[2], env->regwptr[3],
192                               env->regwptr[4], env->regwptr[5],
193                               0, 0);
194             if (ret == -QEMU_ERESTARTSYS || ret == -QEMU_ESIGRETURN) {
195                 break;
196             }
197             if ((abi_ulong)ret >= (abi_ulong)(-515)) {
198                 env->syscall_cc |= PSR_CARRY;
199                 ret = -ret;
200             } else {
201                 env->syscall_cc &= ~PSR_CARRY;
202             }
203             env->regwptr[0] = ret;
204             /* next instruction */
205             env->pc = env->npc;
206             env->npc = env->npc + 4;
207             break;
208 
209         case TT_TRAP + 0x03: /* flush windows */
210             flush_windows(env);
211             /* next instruction */
212             env->pc = env->npc;
213             env->npc = env->npc + 4;
214             break;
215 
216 #ifdef TARGET_SPARC64
217         case TT_TRAP + 0x6e:
218             flush_windows(env);
219             sparc64_get_context(env);
220             break;
221         case TT_TRAP + 0x6f:
222             flush_windows(env);
223             sparc64_set_context(env);
224             break;
225 #endif
226 
227         case TARGET_TT_SPILL: /* window overflow */
228             save_window(env);
229             break;
230         case TARGET_TT_FILL:  /* window underflow */
231             restore_window(env);
232             break;
233 
234         case EXCP_INTERRUPT:
235             /* just indicate that signals should be handled asap */
236             break;
237         case TT_ILL_INSN:
238             force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->pc);
239             break;
240         case EXCP_DEBUG:
241             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
242             break;
243         case EXCP_ATOMIC:
244             cpu_exec_step_atomic(cs);
245             break;
246         default:
247             /*
248              * Most software trap numbers vector to BAD_TRAP.
249              * Handle anything not explicitly matched above.
250              */
251             if (trapnr >= TT_TRAP && trapnr <= TT_TRAP + 0x7f) {
252                 force_sig_fault(TARGET_SIGILL, ILL_ILLTRP, env->pc);
253                 break;
254             }
255             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
256             cpu_dump_state(cs, stderr, 0);
257             exit(EXIT_FAILURE);
258         }
259         process_pending_signals (env);
260     }
261 }
262 
263 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
264 {
265     int i;
266     env->pc = regs->pc;
267     env->npc = regs->npc;
268     env->y = regs->y;
269     for(i = 0; i < 8; i++)
270         env->gregs[i] = regs->u_regs[i];
271     for(i = 0; i < 8; i++)
272         env->regwptr[i] = regs->u_regs[i + 8];
273 }
274