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1 /*
2  *  ARM helper routines
3  *
4  *  Copyright (c) 2005-2007 CodeSourcery, LLC
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library 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 GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 #include "exec.h"
20 #include "helper.h"
21 
22 #define SIGNBIT (uint32_t)0x80000000
23 #define SIGNBIT64 ((uint64_t)1 << 63)
24 
raise_exception(int tt)25 void raise_exception(int tt)
26 {
27     env->exception_index = tt;
28     cpu_loop_exit();
29 }
30 
HELPER(neon_tbl)31 uint32_t HELPER(neon_tbl)(uint32_t ireg, uint32_t def,
32                           uint32_t rn, uint32_t maxindex)
33 {
34     uint32_t val;
35     uint32_t tmp;
36     int index;
37     int shift;
38     uint64_t *table;
39     table = (uint64_t *)&env->vfp.regs[rn];
40     val = 0;
41     for (shift = 0; shift < 32; shift += 8) {
42         index = (ireg >> shift) & 0xff;
43         if (index < maxindex) {
44             tmp = (table[index >> 3] >> ((index & 7) << 3)) & 0xff;
45             val |= tmp << shift;
46         } else {
47             val |= def & (0xff << shift);
48         }
49     }
50     return val;
51 }
52 
53 #if !defined(CONFIG_USER_ONLY)
54 
55 #define MMUSUFFIX _mmu
56 
57 #define SHIFT 0
58 #include "softmmu_template.h"
59 
60 #define SHIFT 1
61 #include "softmmu_template.h"
62 
63 #define SHIFT 2
64 #include "softmmu_template.h"
65 
66 #define SHIFT 3
67 #include "softmmu_template.h"
68 
69 /* try to fill the TLB and return an exception if error. If retaddr is
70    NULL, it means that the function was called in C code (i.e. not
71    from generated code or from helper.c) */
72 /* XXX: fix it to restore all registers */
tlb_fill(target_ulong addr,int is_write,int mmu_idx,void * retaddr)73 void tlb_fill (target_ulong addr, int is_write, int mmu_idx, void *retaddr)
74 {
75     TranslationBlock *tb;
76     CPUState *saved_env;
77     unsigned long pc;
78     int ret;
79 
80     /* XXX: hack to restore env in all cases, even if not called from
81        generated code */
82     saved_env = env;
83     env = cpu_single_env;
84     ret = cpu_arm_handle_mmu_fault(env, addr, is_write, mmu_idx, 1);
85     if (unlikely(ret)) {
86         if (retaddr) {
87             /* now we have a real cpu fault */
88             pc = (unsigned long)retaddr;
89             tb = tb_find_pc(pc);
90             if (tb) {
91                 /* the PC is inside the translated code. It means that we have
92                    a virtual CPU fault */
93                 cpu_restore_state(tb, env, pc);
94             }
95         }
96         raise_exception(env->exception_index);
97     }
98     env = saved_env;
99 }
100 
HELPER(set_cp)101 void HELPER(set_cp)(CPUState *env, uint32_t insn, uint32_t val)
102 {
103     int cp_num = (insn >> 8) & 0xf;
104     int cp_info = (insn >> 5) & 7;
105     int src = (insn >> 16) & 0xf;
106     int operand = insn & 0xf;
107 
108     if (env->cp[cp_num].cp_write)
109         env->cp[cp_num].cp_write(env->cp[cp_num].opaque,
110                                  cp_info, src, operand, val, GETPC());
111         }
112 
HELPER(get_cp)113 uint32_t HELPER(get_cp)(CPUState *env, uint32_t insn)
114 {
115     int cp_num = (insn >> 8) & 0xf;
116     int cp_info = (insn >> 5) & 7;
117     int dest = (insn >> 16) & 0xf;
118     int operand = insn & 0xf;
119 
120     if (env->cp[cp_num].cp_read)
121         return env->cp[cp_num].cp_read(env->cp[cp_num].opaque,
122                                        cp_info, dest, operand, GETPC());
123         return 0;
124 }
125 
126 #else
127 
HELPER(set_cp)128 void HELPER(set_cp)(CPUState *env, uint32_t insn, uint32_t val)
129 {
130     int op1 = (insn >> 8) & 0xf;
131     cpu_abort(env, "cp%i insn %08x\n", op1, insn);
132     return;
133 }
134 
HELPER(get_cp)135 uint32_t HELPER(get_cp)(CPUState *env, uint32_t insn)
136 {
137     int op1 = (insn >> 8) & 0xf;
138     cpu_abort(env, "cp%i insn %08x\n", op1, insn);
139     return 0;
140 }
141 
142 #endif
143 
144 /* FIXME: Pass an axplicit pointer to QF to CPUState, and move saturating
145    instructions into helper.c  */
HELPER(add_setq)146 uint32_t HELPER(add_setq)(uint32_t a, uint32_t b)
147 {
148     uint32_t res = a + b;
149     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT))
150         env->QF = 1;
151     return res;
152 }
153 
HELPER(add_saturate)154 uint32_t HELPER(add_saturate)(uint32_t a, uint32_t b)
155 {
156     uint32_t res = a + b;
157     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) {
158         env->QF = 1;
159         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
160     }
161     return res;
162 }
163 
HELPER(sub_saturate)164 uint32_t HELPER(sub_saturate)(uint32_t a, uint32_t b)
165 {
166     uint32_t res = a - b;
167     if (((res ^ a) & SIGNBIT) && ((a ^ b) & SIGNBIT)) {
168         env->QF = 1;
169         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
170     }
171     return res;
172 }
173 
HELPER(double_saturate)174 uint32_t HELPER(double_saturate)(int32_t val)
175 {
176     uint32_t res;
177     if (val >= 0x40000000) {
178         res = ~SIGNBIT;
179         env->QF = 1;
180     } else if (val <= (int32_t)0xc0000000) {
181         res = SIGNBIT;
182         env->QF = 1;
183     } else {
184         res = val << 1;
185     }
186     return res;
187 }
188 
HELPER(add_usaturate)189 uint32_t HELPER(add_usaturate)(uint32_t a, uint32_t b)
190 {
191     uint32_t res = a + b;
192     if (res < a) {
193         env->QF = 1;
194         res = ~0;
195     }
196     return res;
197 }
198 
HELPER(sub_usaturate)199 uint32_t HELPER(sub_usaturate)(uint32_t a, uint32_t b)
200 {
201     uint32_t res = a - b;
202     if (res > a) {
203         env->QF = 1;
204         res = 0;
205     }
206     return res;
207 }
208 
209 /* Signed saturation.  */
do_ssat(int32_t val,int shift)210 static inline uint32_t do_ssat(int32_t val, int shift)
211 {
212     int32_t top;
213     uint32_t mask;
214 
215     top = val >> shift;
216     mask = (1u << shift) - 1;
217     if (top > 0) {
218         env->QF = 1;
219         return mask;
220     } else if (top < -1) {
221         env->QF = 1;
222         return ~mask;
223     }
224     return val;
225 }
226 
227 /* Unsigned saturation.  */
do_usat(int32_t val,int shift)228 static inline uint32_t do_usat(int32_t val, int shift)
229 {
230     uint32_t max;
231 
232     max = (1u << shift) - 1;
233     if (val < 0) {
234         env->QF = 1;
235         return 0;
236     } else if (val > max) {
237         env->QF = 1;
238         return max;
239     }
240     return val;
241 }
242 
243 /* Signed saturate.  */
HELPER(ssat)244 uint32_t HELPER(ssat)(uint32_t x, uint32_t shift)
245 {
246     return do_ssat(x, shift);
247 }
248 
249 /* Dual halfword signed saturate.  */
HELPER(ssat16)250 uint32_t HELPER(ssat16)(uint32_t x, uint32_t shift)
251 {
252     uint32_t res;
253 
254     res = (uint16_t)do_ssat((int16_t)x, shift);
255     res |= do_ssat(((int32_t)x) >> 16, shift) << 16;
256     return res;
257 }
258 
259 /* Unsigned saturate.  */
HELPER(usat)260 uint32_t HELPER(usat)(uint32_t x, uint32_t shift)
261 {
262     return do_usat(x, shift);
263 }
264 
265 /* Dual halfword unsigned saturate.  */
HELPER(usat16)266 uint32_t HELPER(usat16)(uint32_t x, uint32_t shift)
267 {
268     uint32_t res;
269 
270     res = (uint16_t)do_usat((int16_t)x, shift);
271     res |= do_usat(((int32_t)x) >> 16, shift) << 16;
272     return res;
273 }
274 
HELPER(wfi)275 void HELPER(wfi)(void)
276 {
277     env->exception_index = EXCP_HLT;
278     env->halted = 1;
279     cpu_loop_exit();
280 }
281 
HELPER(exception)282 void HELPER(exception)(uint32_t excp)
283 {
284     env->exception_index = excp;
285     cpu_loop_exit();
286 }
287 
HELPER(cpsr_read)288 uint32_t HELPER(cpsr_read)(void)
289 {
290     return cpsr_read(env) & ~CPSR_EXEC;
291 }
292 
HELPER(cpsr_write)293 void HELPER(cpsr_write)(uint32_t val, uint32_t mask)
294 {
295     cpsr_write(env, val, mask);
296 }
297 
298 /* Access to user mode registers from privileged modes.  */
HELPER(get_user_reg)299 uint32_t HELPER(get_user_reg)(uint32_t regno)
300 {
301     uint32_t val;
302 
303     if (regno == 13) {
304         val = env->banked_r13[0];
305     } else if (regno == 14) {
306         val = env->banked_r14[0];
307     } else if (regno >= 8
308                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
309         val = env->usr_regs[regno - 8];
310     } else {
311         val = env->regs[regno];
312     }
313     return val;
314 }
315 
HELPER(set_user_reg)316 void HELPER(set_user_reg)(uint32_t regno, uint32_t val)
317 {
318     if (regno == 13) {
319         env->banked_r13[0] = val;
320     } else if (regno == 14) {
321         env->banked_r14[0] = val;
322     } else if (regno >= 8
323                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
324         env->usr_regs[regno - 8] = val;
325     } else {
326         env->regs[regno] = val;
327     }
328 }
329 
330 /* ??? Flag setting arithmetic is awkward because we need to do comparisons.
331    The only way to do that in TCG is a conditional branch, which clobbers
332    all our temporaries.  For now implement these as helper functions.  */
333 
HELPER(add_cc)334 uint32_t HELPER (add_cc)(uint32_t a, uint32_t b)
335 {
336     uint32_t result;
337     result = a + b;
338     env->NF = env->ZF = result;
339     env->CF = result < a;
340     env->VF = (a ^ b ^ -1) & (a ^ result);
341     return result;
342 }
343 
HELPER(adc_cc)344 uint32_t HELPER(adc_cc)(uint32_t a, uint32_t b)
345 {
346     uint32_t result;
347     if (!env->CF) {
348         result = a + b;
349         env->CF = result < a;
350     } else {
351         result = a + b + 1;
352         env->CF = result <= a;
353     }
354     env->VF = (a ^ b ^ -1) & (a ^ result);
355     env->NF = env->ZF = result;
356     return result;
357 }
358 
HELPER(sub_cc)359 uint32_t HELPER(sub_cc)(uint32_t a, uint32_t b)
360 {
361     uint32_t result;
362     result = a - b;
363     env->NF = env->ZF = result;
364     env->CF = a >= b;
365     env->VF = (a ^ b) & (a ^ result);
366     return result;
367 }
368 
HELPER(sbc_cc)369 uint32_t HELPER(sbc_cc)(uint32_t a, uint32_t b)
370 {
371     uint32_t result;
372     if (!env->CF) {
373         result = a - b - 1;
374         env->CF = a > b;
375     } else {
376         result = a - b;
377         env->CF = a >= b;
378     }
379     env->VF = (a ^ b) & (a ^ result);
380     env->NF = env->ZF = result;
381     return result;
382 }
383 
384 /* Similarly for variable shift instructions.  */
385 
HELPER(shl)386 uint32_t HELPER(shl)(uint32_t x, uint32_t i)
387 {
388     int shift = i & 0xff;
389     if (shift >= 32)
390         return 0;
391     return x << shift;
392 }
393 
HELPER(shr)394 uint32_t HELPER(shr)(uint32_t x, uint32_t i)
395 {
396     int shift = i & 0xff;
397     if (shift >= 32)
398         return 0;
399     return (uint32_t)x >> shift;
400 }
401 
HELPER(sar)402 uint32_t HELPER(sar)(uint32_t x, uint32_t i)
403 {
404     int shift = i & 0xff;
405     if (shift >= 32)
406         shift = 31;
407     return (int32_t)x >> shift;
408 }
409 
HELPER(shl_cc)410 uint32_t HELPER(shl_cc)(uint32_t x, uint32_t i)
411 {
412     int shift = i & 0xff;
413     if (shift >= 32) {
414         if (shift == 32)
415             env->CF = x & 1;
416         else
417             env->CF = 0;
418         return 0;
419     } else if (shift != 0) {
420         env->CF = (x >> (32 - shift)) & 1;
421         return x << shift;
422     }
423     return x;
424 }
425 
HELPER(shr_cc)426 uint32_t HELPER(shr_cc)(uint32_t x, uint32_t i)
427 {
428     int shift = i & 0xff;
429     if (shift >= 32) {
430         if (shift == 32)
431             env->CF = (x >> 31) & 1;
432         else
433             env->CF = 0;
434         return 0;
435     } else if (shift != 0) {
436         env->CF = (x >> (shift - 1)) & 1;
437         return x >> shift;
438     }
439     return x;
440 }
441 
HELPER(sar_cc)442 uint32_t HELPER(sar_cc)(uint32_t x, uint32_t i)
443 {
444     int shift = i & 0xff;
445     if (shift >= 32) {
446         env->CF = (x >> 31) & 1;
447         return (int32_t)x >> 31;
448     } else if (shift != 0) {
449         env->CF = (x >> (shift - 1)) & 1;
450         return (int32_t)x >> shift;
451     }
452     return x;
453 }
454 
HELPER(ror_cc)455 uint32_t HELPER(ror_cc)(uint32_t x, uint32_t i)
456 {
457     int shift1, shift;
458     shift1 = i & 0xff;
459     shift = shift1 & 0x1f;
460     if (shift == 0) {
461         if (shift1 != 0)
462             env->CF = (x >> 31) & 1;
463         return x;
464     } else {
465         env->CF = (x >> (shift - 1)) & 1;
466         return ((uint32_t)x >> shift) | (x << (32 - shift));
467     }
468 }
469 
HELPER(neon_vldst_all)470 void HELPER(neon_vldst_all)(uint32_t insn)
471 {
472 #if defined(CONFIG_USER_ONLY)
473 #define LDB(addr) ldub(addr)
474 #define LDW(addr) lduw(addr)
475 #define LDL(addr) ldl(addr)
476 #define LDQ(addr) ldq(addr)
477 #define STB(addr, val) stb(addr, val)
478 #define STW(addr, val) stw(addr, val)
479 #define STL(addr, val) stl(addr, val)
480 #define STQ(addr, val) stq(addr, val)
481 #else
482     int user = cpu_mmu_index(env);
483 #define LDB(addr) slow_ldb_mmu(addr, user, GETPC())
484 #define LDW(addr) slow_ldw_mmu(addr, user, GETPC())
485 #define LDL(addr) slow_ldl_mmu(addr, user, GETPC())
486 #define LDQ(addr) slow_ldq_mmu(addr, user, GETPC())
487 #define STB(addr, val) slow_stb_mmu(addr, val, user, GETPC())
488 #define STW(addr, val) slow_stw_mmu(addr, val, user, GETPC())
489 #define STL(addr, val) slow_stl_mmu(addr, val, user, GETPC())
490 #define STQ(addr, val) slow_stq_mmu(addr, val, user, GETPC())
491 #endif
492     static const struct {
493         int nregs;
494         int interleave;
495         int spacing;
496     } neon_ls_element_type[11] = {
497         {4, 4, 1},
498         {4, 4, 2},
499         {4, 1, 1},
500         {4, 2, 1},
501         {3, 3, 1},
502         {3, 3, 2},
503         {3, 1, 1},
504         {1, 1, 1},
505         {2, 2, 1},
506         {2, 2, 2},
507         {2, 1, 1}
508     };
509 
510     const int op = (insn >> 8) & 0xf;
511     const int size = (insn >> 6) & 3;
512     int rd = ((insn >> 12) & 0x0f) | ((insn >> 18) & 0x10);
513     const int rn = (insn >> 16) & 0xf;
514     const int load = (insn & (1 << 21)) != 0;
515     const int nregs = neon_ls_element_type[op].nregs;
516     const int interleave = neon_ls_element_type[op].interleave;
517     const int spacing = neon_ls_element_type[op].spacing;
518     uint32_t addr = env->regs[rn];
519     const int stride = (1 << size) * interleave;
520     int i, reg;
521     uint64_t tmp64;
522 
523     for (reg = 0; reg < nregs; reg++) {
524         if (interleave > 2 || (interleave == 2 && nregs == 2)) {
525             addr = env->regs[rn] + (1 << size) * reg;
526         } else if (interleave == 2 && nregs == 4 && reg == 2) {
527             addr = env->regs[rn] + (1 << size);
528         }
529         switch (size) {
530             case 3:
531                 if (load) {
532                     env->vfp.regs[rd] = make_float64(LDQ(addr));
533                 } else {
534                     STQ(addr, float64_val(env->vfp.regs[rd]));
535                 }
536                 addr += stride;
537                 break;
538             case 2:
539                 if (load) {
540                     tmp64 = (uint32_t)LDL(addr);
541                     addr += stride;
542                     tmp64 |= (uint64_t)LDL(addr) << 32;
543                     addr += stride;
544                     env->vfp.regs[rd] = make_float64(tmp64);
545                 } else {
546                     tmp64 = float64_val(env->vfp.regs[rd]);
547                     STL(addr, tmp64);
548                     addr += stride;
549                     STL(addr, tmp64 >> 32);
550                     addr += stride;
551                 }
552                 break;
553             case 1:
554                 if (load) {
555                     tmp64 = 0ull;
556                     for (i = 0; i < 4; i++, addr += stride) {
557                         tmp64 |= (uint64_t)LDW(addr) << (i * 16);
558                     }
559                     env->vfp.regs[rd] = make_float64(tmp64);
560                 } else {
561                     tmp64 = float64_val(env->vfp.regs[rd]);
562                     for (i = 0; i < 4; i++, addr += stride, tmp64 >>= 16) {
563                         STW(addr, tmp64);
564                     }
565                 }
566                 break;
567             case 0:
568                 if (load) {
569                     tmp64 = 0ull;
570                     for (i = 0; i < 8; i++, addr += stride) {
571                         tmp64 |= (uint64_t)LDB(addr) << (i * 8);
572                     }
573                     env->vfp.regs[rd] = make_float64(tmp64);
574                 } else {
575                     tmp64 = float64_val(env->vfp.regs[rd]);
576                     for (i = 0; i < 8; i++, addr += stride, tmp64 >>= 8) {
577                         STB(addr, tmp64);
578                     }
579                 }
580                 break;
581         }
582         rd += spacing;
583     }
584 #undef LDB
585 #undef LDW
586 #undef LDL
587 #undef LDQ
588 #undef STB
589 #undef STW
590 #undef STL
591 #undef STQ
592 }
593