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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, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA
19  */
20 #include "exec.h"
21 #include "helpers.h"
22 
23 #define SIGNBIT (uint32_t)0x80000000
24 #define SIGNBIT64 ((uint64_t)1 << 63)
25 
raise_exception(int tt)26 void raise_exception(int tt)
27 {
28     env->exception_index = tt;
29     cpu_loop_exit();
30 }
31 
32 /* thread support */
33 
34 static spinlock_t global_cpu_lock = SPIN_LOCK_UNLOCKED;
35 
cpu_lock(void)36 void cpu_lock(void)
37 {
38     spin_lock(&global_cpu_lock);
39 }
40 
cpu_unlock(void)41 void cpu_unlock(void)
42 {
43     spin_unlock(&global_cpu_lock);
44 }
45 
HELPER(neon_tbl)46 uint32_t HELPER(neon_tbl)(uint32_t ireg, uint32_t def,
47                           uint32_t rn, uint32_t maxindex)
48 {
49     uint32_t val;
50     uint32_t tmp;
51     int index;
52     int shift;
53     uint64_t *table;
54     table = (uint64_t *)&env->vfp.regs[rn];
55     val = 0;
56     for (shift = 0; shift < 32; shift += 8) {
57         index = (ireg >> shift) & 0xff;
58         if (index < maxindex) {
59             tmp = (table[index >> 3] >> ((index & 7) << 3)) & 0xff;
60             val |= tmp << shift;
61         } else {
62             val |= def & (0xff << shift);
63         }
64     }
65     return val;
66 }
67 
68 #if !defined(CONFIG_USER_ONLY)
69 
70 static void do_unaligned_access (target_ulong addr, int is_write, int is_user, void *retaddr);
71 
72 #define MMUSUFFIX _mmu
73 //#define ALIGNED_ONLY  1
74 
75 #define SHIFT 0
76 #include "softmmu_template.h"
77 
78 #define SHIFT 1
79 #include "softmmu_template.h"
80 
81 #define SHIFT 2
82 #include "softmmu_template.h"
83 
84 #define SHIFT 3
85 #include "softmmu_template.h"
86 
do_unaligned_access(target_ulong addr,int is_write,int mmu_idx,void * retaddr)87 static void do_unaligned_access (target_ulong addr, int is_write, int mmu_idx, void *retaddr)
88 {
89     //printf("::UNALIGNED:: addr=%lx is_write=%d is_user=%d retaddr=%p\n", addr, is_write, is_user, retaddr);
90     if (mmu_idx)
91     {
92         env = cpu_single_env;
93         env->cp15.c5_data = 0x00000001;  /* corresponds to an alignment fault */
94         env->cp15.c6_data = addr;
95         env->exception_index = EXCP_DATA_ABORT;
96         cpu_loop_exit();
97     }
98 }
99 
100 /* try to fill the TLB and return an exception if error. If retaddr is
101    NULL, it means that the function was called in C code (i.e. not
102    from generated code or from helper.c) */
103 /* XXX: fix it to restore all registers */
tlb_fill(target_ulong addr,int is_write,int mmu_idx,void * retaddr)104 void tlb_fill (target_ulong addr, int is_write, int mmu_idx, void *retaddr)
105 {
106     TranslationBlock *tb;
107     CPUState *saved_env;
108     unsigned long pc;
109     int ret;
110 
111     /* XXX: hack to restore env in all cases, even if not called from
112        generated code */
113     saved_env = env;
114     env = cpu_single_env;
115     ret = cpu_arm_handle_mmu_fault(env, addr, is_write, mmu_idx, 1);
116     if (unlikely(ret)) {
117         if (retaddr) {
118             /* now we have a real cpu fault */
119             pc = (unsigned long)retaddr;
120             tb = tb_find_pc(pc);
121             if (tb) {
122                 /* the PC is inside the translated code. It means that we have
123                    a virtual CPU fault */
124                 cpu_restore_state(tb, env, pc, NULL);
125             }
126         }
127         raise_exception(env->exception_index);
128     }
129     env = saved_env;
130 }
131 
132 /* copy a string from the simulated virtual space to a buffer in QEMU */
vstrcpy(target_ulong ptr,char * buf,int max)133 void vstrcpy(target_ulong ptr, char *buf, int max)
134 {
135     int  index;
136 
137     if (buf == NULL) return;
138 
139     for (index = 0; index < max; index += 1) {
140         cpu_physical_memory_read(ptr + index, buf + index, 1);
141         if (buf[index] == 0)
142             break;
143     }
144 }
145 #endif
146 
147 /* FIXME: Pass an axplicit pointer to QF to CPUState, and move saturating
148    instructions into helper.c  */
HELPER(add_setq)149 uint32_t HELPER(add_setq)(uint32_t a, uint32_t b)
150 {
151     uint32_t res = a + b;
152     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT))
153         env->QF = 1;
154     return res;
155 }
156 
HELPER(add_saturate)157 uint32_t HELPER(add_saturate)(uint32_t a, uint32_t b)
158 {
159     uint32_t res = a + b;
160     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) {
161         env->QF = 1;
162         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
163     }
164     return res;
165 }
166 
HELPER(sub_saturate)167 uint32_t HELPER(sub_saturate)(uint32_t a, uint32_t b)
168 {
169     uint32_t res = a - b;
170     if (((res ^ a) & SIGNBIT) && ((a ^ b) & SIGNBIT)) {
171         env->QF = 1;
172         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
173     }
174     return res;
175 }
176 
HELPER(double_saturate)177 uint32_t HELPER(double_saturate)(int32_t val)
178 {
179     uint32_t res;
180     if (val >= 0x40000000) {
181         res = ~SIGNBIT;
182         env->QF = 1;
183     } else if (val <= (int32_t)0xc0000000) {
184         res = SIGNBIT;
185         env->QF = 1;
186     } else {
187         res = val << 1;
188     }
189     return res;
190 }
191 
HELPER(add_usaturate)192 uint32_t HELPER(add_usaturate)(uint32_t a, uint32_t b)
193 {
194     uint32_t res = a + b;
195     if (res < a) {
196         env->QF = 1;
197         res = ~0;
198     }
199     return res;
200 }
201 
HELPER(sub_usaturate)202 uint32_t HELPER(sub_usaturate)(uint32_t a, uint32_t b)
203 {
204     uint32_t res = a - b;
205     if (res > a) {
206         env->QF = 1;
207         res = 0;
208     }
209     return res;
210 }
211 
212 /* Signed saturation.  */
do_ssat(int32_t val,int shift)213 static inline uint32_t do_ssat(int32_t val, int shift)
214 {
215     int32_t top;
216     uint32_t mask;
217 
218     top = val >> shift;
219     mask = (1u << shift) - 1;
220     if (top > 0) {
221         env->QF = 1;
222         return mask;
223     } else if (top < -1) {
224         env->QF = 1;
225         return ~mask;
226     }
227     return val;
228 }
229 
230 /* Unsigned saturation.  */
do_usat(int32_t val,int shift)231 static inline uint32_t do_usat(int32_t val, int shift)
232 {
233     uint32_t max;
234 
235     max = (1u << shift) - 1;
236     if (val < 0) {
237         env->QF = 1;
238         return 0;
239     } else if (val > max) {
240         env->QF = 1;
241         return max;
242     }
243     return val;
244 }
245 
246 /* Signed saturate.  */
HELPER(ssat)247 uint32_t HELPER(ssat)(uint32_t x, uint32_t shift)
248 {
249     return do_ssat(x, shift);
250 }
251 
252 /* Dual halfword signed saturate.  */
HELPER(ssat16)253 uint32_t HELPER(ssat16)(uint32_t x, uint32_t shift)
254 {
255     uint32_t res;
256 
257     res = (uint16_t)do_ssat((int16_t)x, shift);
258     res |= do_ssat(((int32_t)x) >> 16, shift) << 16;
259     return res;
260 }
261 
262 /* Unsigned saturate.  */
HELPER(usat)263 uint32_t HELPER(usat)(uint32_t x, uint32_t shift)
264 {
265     return do_usat(x, shift);
266 }
267 
268 /* Dual halfword unsigned saturate.  */
HELPER(usat16)269 uint32_t HELPER(usat16)(uint32_t x, uint32_t shift)
270 {
271     uint32_t res;
272 
273     res = (uint16_t)do_usat((int16_t)x, shift);
274     res |= do_usat(((int32_t)x) >> 16, shift) << 16;
275     return res;
276 }
277 
HELPER(wfi)278 void HELPER(wfi)(void)
279 {
280     env->exception_index = EXCP_HLT;
281     env->halted = 1;
282     cpu_loop_exit();
283 }
284 
HELPER(exception)285 void HELPER(exception)(uint32_t excp)
286 {
287     env->exception_index = excp;
288     cpu_loop_exit();
289 }
290 
HELPER(cpsr_read)291 uint32_t HELPER(cpsr_read)(void)
292 {
293     return cpsr_read(env) & ~CPSR_EXEC;
294 }
295 
HELPER(cpsr_write)296 void HELPER(cpsr_write)(uint32_t val, uint32_t mask)
297 {
298     cpsr_write(env, val, mask);
299 }
300 
301 /* Access to user mode registers from privileged modes.  */
HELPER(get_user_reg)302 uint32_t HELPER(get_user_reg)(uint32_t regno)
303 {
304     uint32_t val;
305 
306     if (regno == 13) {
307         val = env->banked_r13[0];
308     } else if (regno == 14) {
309         val = env->banked_r14[0];
310     } else if (regno >= 8
311                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
312         val = env->usr_regs[regno - 8];
313     } else {
314         val = env->regs[regno];
315     }
316     return val;
317 }
318 
HELPER(set_user_reg)319 void HELPER(set_user_reg)(uint32_t regno, uint32_t val)
320 {
321     if (regno == 13) {
322         env->banked_r13[0] = val;
323     } else if (regno == 14) {
324         env->banked_r14[0] = val;
325     } else if (regno >= 8
326                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
327         env->usr_regs[regno - 8] = val;
328     } else {
329         env->regs[regno] = val;
330     }
331 }
332 
333 /* ??? Flag setting arithmetic is awkward because we need to do comparisons.
334    The only way to do that in TCG is a conditional branch, which clobbers
335    all our temporaries.  For now implement these as helper functions.  */
336 
HELPER(add_cc)337 uint32_t HELPER (add_cc)(uint32_t a, uint32_t b)
338 {
339     uint32_t result;
340     result = a + b;
341     env->NF = env->ZF = result;
342     env->CF = result < a;
343     env->VF = (a ^ b ^ -1) & (a ^ result);
344     return result;
345 }
346 
HELPER(adc_cc)347 uint32_t HELPER(adc_cc)(uint32_t a, uint32_t b)
348 {
349     uint32_t result;
350     if (!env->CF) {
351         result = a + b;
352         env->CF = result < a;
353     } else {
354         result = a + b + 1;
355         env->CF = result <= a;
356     }
357     env->VF = (a ^ b ^ -1) & (a ^ result);
358     env->NF = env->ZF = result;
359     return result;
360 }
361 
HELPER(sub_cc)362 uint32_t HELPER(sub_cc)(uint32_t a, uint32_t b)
363 {
364     uint32_t result;
365     result = a - b;
366     env->NF = env->ZF = result;
367     env->CF = a >= b;
368     env->VF = (a ^ b) & (a ^ result);
369     return result;
370 }
371 
HELPER(sbc_cc)372 uint32_t HELPER(sbc_cc)(uint32_t a, uint32_t b)
373 {
374     uint32_t result;
375     if (!env->CF) {
376         result = a - b - 1;
377         env->CF = a > b;
378     } else {
379         result = a - b;
380         env->CF = a >= b;
381     }
382     env->VF = (a ^ b) & (a ^ result);
383     env->NF = env->ZF = result;
384     return result;
385 }
386 
387 /* Similarly for variable shift instructions.  */
388 
HELPER(shl)389 uint32_t HELPER(shl)(uint32_t x, uint32_t i)
390 {
391     int shift = i & 0xff;
392     if (shift >= 32)
393         return 0;
394     return x << shift;
395 }
396 
HELPER(shr)397 uint32_t HELPER(shr)(uint32_t x, uint32_t i)
398 {
399     int shift = i & 0xff;
400     if (shift >= 32)
401         return 0;
402     return (uint32_t)x >> shift;
403 }
404 
HELPER(sar)405 uint32_t HELPER(sar)(uint32_t x, uint32_t i)
406 {
407     int shift = i & 0xff;
408     if (shift >= 32)
409         shift = 31;
410     return (int32_t)x >> shift;
411 }
412 
HELPER(ror)413 uint32_t HELPER(ror)(uint32_t x, uint32_t i)
414 {
415     int shift = i & 0xff;
416     if (shift == 0)
417         return x;
418     return (x >> shift) | (x << (32 - shift));
419 }
420 
HELPER(shl_cc)421 uint32_t HELPER(shl_cc)(uint32_t x, uint32_t i)
422 {
423     int shift = i & 0xff;
424     if (shift >= 32) {
425         if (shift == 32)
426             env->CF = x & 1;
427         else
428             env->CF = 0;
429         return 0;
430     } else if (shift != 0) {
431         env->CF = (x >> (32 - shift)) & 1;
432         return x << shift;
433     }
434     return x;
435 }
436 
HELPER(shr_cc)437 uint32_t HELPER(shr_cc)(uint32_t x, uint32_t i)
438 {
439     int shift = i & 0xff;
440     if (shift >= 32) {
441         if (shift == 32)
442             env->CF = (x >> 31) & 1;
443         else
444             env->CF = 0;
445         return 0;
446     } else if (shift != 0) {
447         env->CF = (x >> (shift - 1)) & 1;
448         return x >> shift;
449     }
450     return x;
451 }
452 
HELPER(sar_cc)453 uint32_t HELPER(sar_cc)(uint32_t x, uint32_t i)
454 {
455     int shift = i & 0xff;
456     if (shift >= 32) {
457         env->CF = (x >> 31) & 1;
458         return (int32_t)x >> 31;
459     } else if (shift != 0) {
460         env->CF = (x >> (shift - 1)) & 1;
461         return (int32_t)x >> shift;
462     }
463     return x;
464 }
465 
HELPER(ror_cc)466 uint32_t HELPER(ror_cc)(uint32_t x, uint32_t i)
467 {
468     int shift1, shift;
469     shift1 = i & 0xff;
470     shift = shift1 & 0x1f;
471     if (shift == 0) {
472         if (shift1 != 0)
473             env->CF = (x >> 31) & 1;
474         return x;
475     } else {
476         env->CF = (x >> (shift - 1)) & 1;
477         return ((uint32_t)x >> shift) | (x << (32 - shift));
478     }
479 }
480 
HELPER(neon_add_saturate_s64)481 uint64_t HELPER(neon_add_saturate_s64)(uint64_t src1, uint64_t src2)
482 {
483     uint64_t res;
484 
485     res = src1 + src2;
486     if (((res ^ src1) & SIGNBIT64) && !((src1 ^ src2) & SIGNBIT64)) {
487         env->QF = 1;
488         res = ((int64_t)src1 >> 63) ^ ~SIGNBIT64;
489     }
490     return res;
491 }
492 
HELPER(neon_add_saturate_u64)493 uint64_t HELPER(neon_add_saturate_u64)(uint64_t src1, uint64_t src2)
494 {
495     uint64_t res;
496 
497     res = src1 + src2;
498     if (res < src1) {
499         env->QF = 1;
500         res = ~(uint64_t)0;
501     }
502     return res;
503 }
504 
HELPER(neon_sub_saturate_s64)505 uint64_t HELPER(neon_sub_saturate_s64)(uint64_t src1, uint64_t src2)
506 {
507     uint64_t res;
508 
509     res = src1 - src2;
510     if (((res ^ src1) & SIGNBIT64) && ((src1 ^ src2) & SIGNBIT64)) {
511         env->QF = 1;
512         res = ((int64_t)src1 >> 63) ^ ~SIGNBIT64;
513     }
514     return res;
515 }
516 
HELPER(neon_sub_saturate_u64)517 uint64_t HELPER(neon_sub_saturate_u64)(uint64_t src1, uint64_t src2)
518 {
519     uint64_t res;
520 
521     if (src1 < src2) {
522         env->QF = 1;
523         res = 0;
524     } else {
525         res = src1 - src2;
526     }
527     return res;
528 }
529 
530 /* These need to return a pair of value, so still use T0/T1.  */
531 /* Transpose.  Argument order is rather strange to avoid special casing
532    the tranlation code.
533    On input T0 = rm, T1 = rd.  On output T0 = rd, T1 = rm  */
HELPER(neon_trn_u8)534 void HELPER(neon_trn_u8)(void)
535 {
536     uint32_t rd;
537     uint32_t rm;
538     rd = ((T0 & 0x00ff00ff) << 8) | (T1 & 0x00ff00ff);
539     rm = ((T1 & 0xff00ff00) >> 8) | (T0 & 0xff00ff00);
540     T0 = rd;
541     T1 = rm;
542 }
543 
HELPER(neon_trn_u16)544 void HELPER(neon_trn_u16)(void)
545 {
546     uint32_t rd;
547     uint32_t rm;
548     rd = (T0 << 16) | (T1 & 0xffff);
549     rm = (T1 >> 16) | (T0 & 0xffff0000);
550     T0 = rd;
551     T1 = rm;
552 }
553 
554 /* Worker routines for zip and unzip.  */
HELPER(neon_unzip_u8)555 void HELPER(neon_unzip_u8)(void)
556 {
557     uint32_t rd;
558     uint32_t rm;
559     rd = (T0 & 0xff) | ((T0 >> 8) & 0xff00)
560          | ((T1 << 16) & 0xff0000) | ((T1 << 8) & 0xff000000);
561     rm = ((T0 >> 8) & 0xff) | ((T0 >> 16) & 0xff00)
562          | ((T1 << 8) & 0xff0000) | (T1 & 0xff000000);
563     T0 = rd;
564     T1 = rm;
565 }
566 
HELPER(neon_zip_u8)567 void HELPER(neon_zip_u8)(void)
568 {
569     uint32_t rd;
570     uint32_t rm;
571     rd = (T0 & 0xff) | ((T1 << 8) & 0xff00)
572          | ((T0 << 16) & 0xff0000) | ((T1 << 24) & 0xff000000);
573     rm = ((T0 >> 16) & 0xff) | ((T1 >> 8) & 0xff00)
574          | ((T0 >> 8) & 0xff0000) | (T1 & 0xff000000);
575     T0 = rd;
576     T1 = rm;
577 }
578 
HELPER(neon_zip_u16)579 void HELPER(neon_zip_u16)(void)
580 {
581     uint32_t tmp;
582 
583     tmp = (T0 & 0xffff) | (T1 << 16);
584     T1 = (T1 & 0xffff0000) | (T0 >> 16);
585     T0 = tmp;
586 }
587