xref: /qemu/target/arm/tcg/helper-a64.c (revision df6fe2abf2e990f767ce755d426bc439c7bba336)
1 /*
2  *  AArch64 specific helpers
3  *
4  *  Copyright (c) 2013 Alexander Graf <agraf@suse.de>
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 2.1 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 
20 #include "qemu/osdep.h"
21 #include "qemu/units.h"
22 #include "cpu.h"
23 #include "gdbstub/helpers.h"
24 #include "exec/helper-proto.h"
25 #include "qemu/host-utils.h"
26 #include "qemu/log.h"
27 #include "qemu/main-loop.h"
28 #include "qemu/bitops.h"
29 #include "internals.h"
30 #include "qemu/crc32c.h"
31 #include "exec/cpu-common.h"
32 #include "accel/tcg/cpu-ldst.h"
33 #include "accel/tcg/helper-retaddr.h"
34 #include "accel/tcg/probe.h"
35 #include "exec/target_page.h"
36 #include "exec/tlb-flags.h"
37 #include "qemu/int128.h"
38 #include "qemu/atomic128.h"
39 #include "fpu/softfloat.h"
40 #include <zlib.h> /* for crc32 */
41 #ifdef CONFIG_USER_ONLY
42 #include "user/page-protection.h"
43 #endif
44 #include "vec_internal.h"
45 
46 /* C2.4.7 Multiply and divide */
47 /* special cases for 0 and LLONG_MIN are mandated by the standard */
48 uint64_t HELPER(udiv64)(uint64_t num, uint64_t den)
49 {
50     if (den == 0) {
51         return 0;
52     }
53     return num / den;
54 }
55 
56 int64_t HELPER(sdiv64)(int64_t num, int64_t den)
57 {
58     if (den == 0) {
59         return 0;
60     }
61     if (num == LLONG_MIN && den == -1) {
62         return LLONG_MIN;
63     }
64     return num / den;
65 }
66 
67 uint64_t HELPER(rbit64)(uint64_t x)
68 {
69     return revbit64(x);
70 }
71 
72 void HELPER(msr_i_spsel)(CPUARMState *env, uint32_t imm)
73 {
74     update_spsel(env, imm);
75 }
76 
77 void HELPER(msr_set_allint_el1)(CPUARMState *env)
78 {
79     /* ALLINT update to PSTATE. */
80     if (arm_hcrx_el2_eff(env) & HCRX_TALLINT) {
81         raise_exception_ra(env, EXCP_UDEF,
82                            syn_aa64_sysregtrap(0, 1, 0, 4, 1, 0x1f, 0), 2,
83                            GETPC());
84     }
85 
86     env->pstate |= PSTATE_ALLINT;
87 }
88 
89 static void daif_check(CPUARMState *env, uint32_t op,
90                        uint32_t imm, uintptr_t ra)
91 {
92     /* DAIF update to PSTATE. This is OK from EL0 only if UMA is set.  */
93     if (arm_current_el(env) == 0 && !(arm_sctlr(env, 0) & SCTLR_UMA)) {
94         raise_exception_ra(env, EXCP_UDEF,
95                            syn_aa64_sysregtrap(0, extract32(op, 0, 3),
96                                                extract32(op, 3, 3), 4,
97                                                imm, 0x1f, 0),
98                            exception_target_el(env), ra);
99     }
100 }
101 
102 void HELPER(msr_i_daifset)(CPUARMState *env, uint32_t imm)
103 {
104     daif_check(env, 0x1e, imm, GETPC());
105     env->daif |= (imm << 6) & PSTATE_DAIF;
106     arm_rebuild_hflags(env);
107 }
108 
109 void HELPER(msr_i_daifclear)(CPUARMState *env, uint32_t imm)
110 {
111     daif_check(env, 0x1f, imm, GETPC());
112     env->daif &= ~((imm << 6) & PSTATE_DAIF);
113     arm_rebuild_hflags(env);
114 }
115 
116 /* Convert a softfloat float_relation_ (as returned by
117  * the float*_compare functions) to the correct ARM
118  * NZCV flag state.
119  */
120 static inline uint32_t float_rel_to_flags(int res)
121 {
122     uint64_t flags;
123     switch (res) {
124     case float_relation_equal:
125         flags = PSTATE_Z | PSTATE_C;
126         break;
127     case float_relation_less:
128         flags = PSTATE_N;
129         break;
130     case float_relation_greater:
131         flags = PSTATE_C;
132         break;
133     case float_relation_unordered:
134     default:
135         flags = PSTATE_C | PSTATE_V;
136         break;
137     }
138     return flags;
139 }
140 
141 uint64_t HELPER(vfp_cmph_a64)(uint32_t x, uint32_t y, float_status *fp_status)
142 {
143     return float_rel_to_flags(float16_compare_quiet(x, y, fp_status));
144 }
145 
146 uint64_t HELPER(vfp_cmpeh_a64)(uint32_t x, uint32_t y, float_status *fp_status)
147 {
148     return float_rel_to_flags(float16_compare(x, y, fp_status));
149 }
150 
151 uint64_t HELPER(vfp_cmps_a64)(float32 x, float32 y, float_status *fp_status)
152 {
153     return float_rel_to_flags(float32_compare_quiet(x, y, fp_status));
154 }
155 
156 uint64_t HELPER(vfp_cmpes_a64)(float32 x, float32 y, float_status *fp_status)
157 {
158     return float_rel_to_flags(float32_compare(x, y, fp_status));
159 }
160 
161 uint64_t HELPER(vfp_cmpd_a64)(float64 x, float64 y, float_status *fp_status)
162 {
163     return float_rel_to_flags(float64_compare_quiet(x, y, fp_status));
164 }
165 
166 uint64_t HELPER(vfp_cmped_a64)(float64 x, float64 y, float_status *fp_status)
167 {
168     return float_rel_to_flags(float64_compare(x, y, fp_status));
169 }
170 
171 float32 HELPER(vfp_mulxs)(float32 a, float32 b, float_status *fpst)
172 {
173     a = float32_squash_input_denormal(a, fpst);
174     b = float32_squash_input_denormal(b, fpst);
175 
176     if ((float32_is_zero(a) && float32_is_infinity(b)) ||
177         (float32_is_infinity(a) && float32_is_zero(b))) {
178         /* 2.0 with the sign bit set to sign(A) XOR sign(B) */
179         return make_float32((1U << 30) |
180                             ((float32_val(a) ^ float32_val(b)) & (1U << 31)));
181     }
182     return float32_mul(a, b, fpst);
183 }
184 
185 float64 HELPER(vfp_mulxd)(float64 a, float64 b, float_status *fpst)
186 {
187     a = float64_squash_input_denormal(a, fpst);
188     b = float64_squash_input_denormal(b, fpst);
189 
190     if ((float64_is_zero(a) && float64_is_infinity(b)) ||
191         (float64_is_infinity(a) && float64_is_zero(b))) {
192         /* 2.0 with the sign bit set to sign(A) XOR sign(B) */
193         return make_float64((1ULL << 62) |
194                             ((float64_val(a) ^ float64_val(b)) & (1ULL << 63)));
195     }
196     return float64_mul(a, b, fpst);
197 }
198 
199 /* 64bit/double versions of the neon float compare functions */
200 uint64_t HELPER(neon_ceq_f64)(float64 a, float64 b, float_status *fpst)
201 {
202     return -float64_eq_quiet(a, b, fpst);
203 }
204 
205 uint64_t HELPER(neon_cge_f64)(float64 a, float64 b, float_status *fpst)
206 {
207     return -float64_le(b, a, fpst);
208 }
209 
210 uint64_t HELPER(neon_cgt_f64)(float64 a, float64 b, float_status *fpst)
211 {
212     return -float64_lt(b, a, fpst);
213 }
214 
215 /*
216  * Reciprocal step and sqrt step. Note that unlike the A32/T32
217  * versions, these do a fully fused multiply-add or
218  * multiply-add-and-halve.
219  * The FPCR.AH == 1 versions need to avoid flipping the sign of NaN.
220  */
221 #define DO_RECPS(NAME, CTYPE, FLOATTYPE, CHSFN)                         \
222     CTYPE HELPER(NAME)(CTYPE a, CTYPE b, float_status *fpst)            \
223     {                                                                   \
224         a = FLOATTYPE ## _squash_input_denormal(a, fpst);               \
225         b = FLOATTYPE ## _squash_input_denormal(b, fpst);               \
226         a = FLOATTYPE ## _ ## CHSFN(a);                                 \
227         if ((FLOATTYPE ## _is_infinity(a) && FLOATTYPE ## _is_zero(b)) || \
228             (FLOATTYPE ## _is_infinity(b) && FLOATTYPE ## _is_zero(a))) { \
229             return FLOATTYPE ## _two;                                   \
230         }                                                               \
231         return FLOATTYPE ## _muladd(a, b, FLOATTYPE ## _two, 0, fpst);  \
232     }
233 
234 DO_RECPS(recpsf_f16, uint32_t, float16, chs)
235 DO_RECPS(recpsf_f32, float32, float32, chs)
236 DO_RECPS(recpsf_f64, float64, float64, chs)
237 DO_RECPS(recpsf_ah_f16, uint32_t, float16, ah_chs)
238 DO_RECPS(recpsf_ah_f32, float32, float32, ah_chs)
239 DO_RECPS(recpsf_ah_f64, float64, float64, ah_chs)
240 
241 #define DO_RSQRTSF(NAME, CTYPE, FLOATTYPE, CHSFN)                       \
242     CTYPE HELPER(NAME)(CTYPE a, CTYPE b, float_status *fpst)            \
243     {                                                                   \
244         a = FLOATTYPE ## _squash_input_denormal(a, fpst);               \
245         b = FLOATTYPE ## _squash_input_denormal(b, fpst);               \
246         a = FLOATTYPE ## _ ## CHSFN(a);                                 \
247         if ((FLOATTYPE ## _is_infinity(a) && FLOATTYPE ## _is_zero(b)) || \
248             (FLOATTYPE ## _is_infinity(b) && FLOATTYPE ## _is_zero(a))) { \
249             return FLOATTYPE ## _one_point_five;                        \
250         }                                                               \
251         return FLOATTYPE ## _muladd_scalbn(a, b, FLOATTYPE ## _three,   \
252                                            -1, 0, fpst);                \
253     }                                                                   \
254 
255 DO_RSQRTSF(rsqrtsf_f16, uint32_t, float16, chs)
256 DO_RSQRTSF(rsqrtsf_f32, float32, float32, chs)
257 DO_RSQRTSF(rsqrtsf_f64, float64, float64, chs)
258 DO_RSQRTSF(rsqrtsf_ah_f16, uint32_t, float16, ah_chs)
259 DO_RSQRTSF(rsqrtsf_ah_f32, float32, float32, ah_chs)
260 DO_RSQRTSF(rsqrtsf_ah_f64, float64, float64, ah_chs)
261 
262 /* Floating-point reciprocal exponent - see FPRecpX in ARM ARM */
263 uint32_t HELPER(frecpx_f16)(uint32_t a, float_status *fpst)
264 {
265     uint16_t val16, sbit;
266     int16_t exp;
267 
268     if (float16_is_any_nan(a)) {
269         float16 nan = a;
270         if (float16_is_signaling_nan(a, fpst)) {
271             float_raise(float_flag_invalid, fpst);
272             if (!fpst->default_nan_mode) {
273                 nan = float16_silence_nan(a, fpst);
274             }
275         }
276         if (fpst->default_nan_mode) {
277             nan = float16_default_nan(fpst);
278         }
279         return nan;
280     }
281 
282     a = float16_squash_input_denormal(a, fpst);
283 
284     val16 = float16_val(a);
285     sbit = 0x8000 & val16;
286     exp = extract32(val16, 10, 5);
287 
288     if (exp == 0) {
289         return make_float16(deposit32(sbit, 10, 5, 0x1e));
290     } else {
291         return make_float16(deposit32(sbit, 10, 5, ~exp));
292     }
293 }
294 
295 float32 HELPER(frecpx_f32)(float32 a, float_status *fpst)
296 {
297     uint32_t val32, sbit;
298     int32_t exp;
299 
300     if (float32_is_any_nan(a)) {
301         float32 nan = a;
302         if (float32_is_signaling_nan(a, fpst)) {
303             float_raise(float_flag_invalid, fpst);
304             if (!fpst->default_nan_mode) {
305                 nan = float32_silence_nan(a, fpst);
306             }
307         }
308         if (fpst->default_nan_mode) {
309             nan = float32_default_nan(fpst);
310         }
311         return nan;
312     }
313 
314     a = float32_squash_input_denormal(a, fpst);
315 
316     val32 = float32_val(a);
317     sbit = 0x80000000ULL & val32;
318     exp = extract32(val32, 23, 8);
319 
320     if (exp == 0) {
321         return make_float32(sbit | (0xfe << 23));
322     } else {
323         return make_float32(sbit | (~exp & 0xff) << 23);
324     }
325 }
326 
327 float64 HELPER(frecpx_f64)(float64 a, float_status *fpst)
328 {
329     uint64_t val64, sbit;
330     int64_t exp;
331 
332     if (float64_is_any_nan(a)) {
333         float64 nan = a;
334         if (float64_is_signaling_nan(a, fpst)) {
335             float_raise(float_flag_invalid, fpst);
336             if (!fpst->default_nan_mode) {
337                 nan = float64_silence_nan(a, fpst);
338             }
339         }
340         if (fpst->default_nan_mode) {
341             nan = float64_default_nan(fpst);
342         }
343         return nan;
344     }
345 
346     a = float64_squash_input_denormal(a, fpst);
347 
348     val64 = float64_val(a);
349     sbit = 0x8000000000000000ULL & val64;
350     exp = extract64(float64_val(a), 52, 11);
351 
352     if (exp == 0) {
353         return make_float64(sbit | (0x7feULL << 52));
354     } else {
355         return make_float64(sbit | (~exp & 0x7ffULL) << 52);
356     }
357 }
358 
359 float32 HELPER(fcvtx_f64_to_f32)(float64 a, float_status *fpst)
360 {
361     float32 r;
362     int old = get_float_rounding_mode(fpst);
363 
364     set_float_rounding_mode(float_round_to_odd, fpst);
365     r = float64_to_float32(a, fpst);
366     set_float_rounding_mode(old, fpst);
367     return r;
368 }
369 
370 /*
371  * AH=1 min/max have some odd special cases:
372  * comparing two zeroes (regardless of sign), (NaN, anything),
373  * or (anything, NaN) should return the second argument (possibly
374  * squashed to zero).
375  * Also, denormal outputs are not squashed to zero regardless of FZ or FZ16.
376  */
377 #define AH_MINMAX_HELPER(NAME, CTYPE, FLOATTYPE, MINMAX)                \
378     CTYPE HELPER(NAME)(CTYPE a, CTYPE b, float_status *fpst)            \
379     {                                                                   \
380         bool save;                                                      \
381         CTYPE r;                                                        \
382         a = FLOATTYPE ## _squash_input_denormal(a, fpst);               \
383         b = FLOATTYPE ## _squash_input_denormal(b, fpst);               \
384         if (FLOATTYPE ## _is_zero(a) && FLOATTYPE ## _is_zero(b)) {     \
385             return b;                                                   \
386         }                                                               \
387         if (FLOATTYPE ## _is_any_nan(a) ||                              \
388             FLOATTYPE ## _is_any_nan(b)) {                              \
389             float_raise(float_flag_invalid, fpst);                      \
390             return b;                                                   \
391         }                                                               \
392         save = get_flush_to_zero(fpst);                                 \
393         set_flush_to_zero(false, fpst);                                 \
394         r = FLOATTYPE ## _ ## MINMAX(a, b, fpst);                       \
395         set_flush_to_zero(save, fpst);                                  \
396         return r;                                                       \
397     }
398 
399 AH_MINMAX_HELPER(vfp_ah_minh, dh_ctype_f16, float16, min)
400 AH_MINMAX_HELPER(vfp_ah_mins, float32, float32, min)
401 AH_MINMAX_HELPER(vfp_ah_mind, float64, float64, min)
402 AH_MINMAX_HELPER(vfp_ah_maxh, dh_ctype_f16, float16, max)
403 AH_MINMAX_HELPER(vfp_ah_maxs, float32, float32, max)
404 AH_MINMAX_HELPER(vfp_ah_maxd, float64, float64, max)
405 AH_MINMAX_HELPER(sme2_ah_fmax_b16, bfloat16, bfloat16, max)
406 AH_MINMAX_HELPER(sme2_ah_fmin_b16, bfloat16, bfloat16, min)
407 
408 /* 64-bit versions of the CRC helpers. Note that although the operation
409  * (and the prototypes of crc32c() and crc32() mean that only the bottom
410  * 32 bits of the accumulator and result are used, we pass and return
411  * uint64_t for convenience of the generated code. Unlike the 32-bit
412  * instruction set versions, val may genuinely have 64 bits of data in it.
413  * The upper bytes of val (above the number specified by 'bytes') must have
414  * been zeroed out by the caller.
415  */
416 uint64_t HELPER(crc32_64)(uint64_t acc, uint64_t val, uint32_t bytes)
417 {
418     uint8_t buf[8];
419 
420     stq_le_p(buf, val);
421 
422     /* zlib crc32 converts the accumulator and output to one's complement.  */
423     return crc32(acc ^ 0xffffffff, buf, bytes) ^ 0xffffffff;
424 }
425 
426 uint64_t HELPER(crc32c_64)(uint64_t acc, uint64_t val, uint32_t bytes)
427 {
428     uint8_t buf[8];
429 
430     stq_le_p(buf, val);
431 
432     /* Linux crc32c converts the output to one's complement.  */
433     return crc32c(acc, buf, bytes) ^ 0xffffffff;
434 }
435 
436 /*
437  * AdvSIMD half-precision
438  */
439 
440 #define ADVSIMD_HELPER(name, suffix) HELPER(glue(glue(advsimd_, name), suffix))
441 
442 #define ADVSIMD_HALFOP(name) \
443 uint32_t ADVSIMD_HELPER(name, h)(uint32_t a, uint32_t b, float_status *fpst) \
444 { \
445     return float16_ ## name(a, b, fpst);    \
446 }
447 
448 #define ADVSIMD_TWOHALFOP(name)                                         \
449 uint32_t ADVSIMD_HELPER(name, 2h)(uint32_t two_a, uint32_t two_b,       \
450                                   float_status *fpst)                   \
451 { \
452     float16  a1, a2, b1, b2;                        \
453     uint32_t r1, r2;                                \
454     a1 = extract32(two_a, 0, 16);                   \
455     a2 = extract32(two_a, 16, 16);                  \
456     b1 = extract32(two_b, 0, 16);                   \
457     b2 = extract32(two_b, 16, 16);                  \
458     r1 = float16_ ## name(a1, b1, fpst);            \
459     r2 = float16_ ## name(a2, b2, fpst);            \
460     return deposit32(r1, 16, 16, r2);               \
461 }
462 
463 ADVSIMD_TWOHALFOP(add)
464 ADVSIMD_TWOHALFOP(sub)
465 ADVSIMD_TWOHALFOP(mul)
466 ADVSIMD_TWOHALFOP(div)
467 ADVSIMD_TWOHALFOP(min)
468 ADVSIMD_TWOHALFOP(max)
469 ADVSIMD_TWOHALFOP(minnum)
470 ADVSIMD_TWOHALFOP(maxnum)
471 
472 /* Data processing - scalar floating-point and advanced SIMD */
473 static float16 float16_mulx(float16 a, float16 b, float_status *fpst)
474 {
475     a = float16_squash_input_denormal(a, fpst);
476     b = float16_squash_input_denormal(b, fpst);
477 
478     if ((float16_is_zero(a) && float16_is_infinity(b)) ||
479         (float16_is_infinity(a) && float16_is_zero(b))) {
480         /* 2.0 with the sign bit set to sign(A) XOR sign(B) */
481         return make_float16((1U << 14) |
482                             ((float16_val(a) ^ float16_val(b)) & (1U << 15)));
483     }
484     return float16_mul(a, b, fpst);
485 }
486 
487 ADVSIMD_HALFOP(mulx)
488 ADVSIMD_TWOHALFOP(mulx)
489 
490 /* fused multiply-accumulate */
491 uint32_t HELPER(advsimd_muladdh)(uint32_t a, uint32_t b, uint32_t c,
492                                  float_status *fpst)
493 {
494     return float16_muladd(a, b, c, 0, fpst);
495 }
496 
497 uint32_t HELPER(advsimd_muladd2h)(uint32_t two_a, uint32_t two_b,
498                                   uint32_t two_c, float_status *fpst)
499 {
500     float16  a1, a2, b1, b2, c1, c2;
501     uint32_t r1, r2;
502     a1 = extract32(two_a, 0, 16);
503     a2 = extract32(two_a, 16, 16);
504     b1 = extract32(two_b, 0, 16);
505     b2 = extract32(two_b, 16, 16);
506     c1 = extract32(two_c, 0, 16);
507     c2 = extract32(two_c, 16, 16);
508     r1 = float16_muladd(a1, b1, c1, 0, fpst);
509     r2 = float16_muladd(a2, b2, c2, 0, fpst);
510     return deposit32(r1, 16, 16, r2);
511 }
512 
513 /*
514  * Floating point comparisons produce an integer result. Softfloat
515  * routines return float_relation types which we convert to the 0/-1
516  * Neon requires.
517  */
518 
519 #define ADVSIMD_CMPRES(test) (test) ? 0xffff : 0
520 
521 uint32_t HELPER(advsimd_ceq_f16)(uint32_t a, uint32_t b, float_status *fpst)
522 {
523     int compare = float16_compare_quiet(a, b, fpst);
524     return ADVSIMD_CMPRES(compare == float_relation_equal);
525 }
526 
527 uint32_t HELPER(advsimd_cge_f16)(uint32_t a, uint32_t b, float_status *fpst)
528 {
529     int compare = float16_compare(a, b, fpst);
530     return ADVSIMD_CMPRES(compare == float_relation_greater ||
531                           compare == float_relation_equal);
532 }
533 
534 uint32_t HELPER(advsimd_cgt_f16)(uint32_t a, uint32_t b, float_status *fpst)
535 {
536     int compare = float16_compare(a, b, fpst);
537     return ADVSIMD_CMPRES(compare == float_relation_greater);
538 }
539 
540 uint32_t HELPER(advsimd_acge_f16)(uint32_t a, uint32_t b, float_status *fpst)
541 {
542     float16 f0 = float16_abs(a);
543     float16 f1 = float16_abs(b);
544     int compare = float16_compare(f0, f1, fpst);
545     return ADVSIMD_CMPRES(compare == float_relation_greater ||
546                           compare == float_relation_equal);
547 }
548 
549 uint32_t HELPER(advsimd_acgt_f16)(uint32_t a, uint32_t b, float_status *fpst)
550 {
551     float16 f0 = float16_abs(a);
552     float16 f1 = float16_abs(b);
553     int compare = float16_compare(f0, f1, fpst);
554     return ADVSIMD_CMPRES(compare == float_relation_greater);
555 }
556 
557 /* round to integral */
558 uint32_t HELPER(advsimd_rinth_exact)(uint32_t x, float_status *fp_status)
559 {
560     return float16_round_to_int(x, fp_status);
561 }
562 
563 uint32_t HELPER(advsimd_rinth)(uint32_t x, float_status *fp_status)
564 {
565     int old_flags = get_float_exception_flags(fp_status), new_flags;
566     float16 ret;
567 
568     ret = float16_round_to_int(x, fp_status);
569 
570     /* Suppress any inexact exceptions the conversion produced */
571     if (!(old_flags & float_flag_inexact)) {
572         new_flags = get_float_exception_flags(fp_status);
573         set_float_exception_flags(new_flags & ~float_flag_inexact, fp_status);
574     }
575 
576     return ret;
577 }
578 
579 static int el_from_spsr(uint32_t spsr)
580 {
581     /* Return the exception level that this SPSR is requesting a return to,
582      * or -1 if it is invalid (an illegal return)
583      */
584     if (spsr & PSTATE_nRW) {
585         switch (spsr & CPSR_M) {
586         case ARM_CPU_MODE_USR:
587             return 0;
588         case ARM_CPU_MODE_HYP:
589             return 2;
590         case ARM_CPU_MODE_FIQ:
591         case ARM_CPU_MODE_IRQ:
592         case ARM_CPU_MODE_SVC:
593         case ARM_CPU_MODE_ABT:
594         case ARM_CPU_MODE_UND:
595         case ARM_CPU_MODE_SYS:
596             return 1;
597         case ARM_CPU_MODE_MON:
598             /* Returning to Mon from AArch64 is never possible,
599              * so this is an illegal return.
600              */
601         default:
602             return -1;
603         }
604     } else {
605         if (extract32(spsr, 1, 1)) {
606             /* Return with reserved M[1] bit set */
607             return -1;
608         }
609         if (extract32(spsr, 0, 4) == 1) {
610             /* return to EL0 with M[0] bit set */
611             return -1;
612         }
613         return extract32(spsr, 2, 2);
614     }
615 }
616 
617 static void cpsr_write_from_spsr_elx(CPUARMState *env,
618                                      uint32_t val)
619 {
620     uint32_t mask;
621 
622     /* Save SPSR_ELx.SS into PSTATE. */
623     env->pstate = (env->pstate & ~PSTATE_SS) | (val & PSTATE_SS);
624     val &= ~PSTATE_SS;
625 
626     /* Move DIT to the correct location for CPSR */
627     if (val & PSTATE_DIT) {
628         val &= ~PSTATE_DIT;
629         val |= CPSR_DIT;
630     }
631 
632     mask = aarch32_cpsr_valid_mask(env->features, \
633         &env_archcpu(env)->isar);
634     cpsr_write(env, val, mask, CPSRWriteRaw);
635 }
636 
637 void HELPER(exception_return)(CPUARMState *env, uint64_t new_pc)
638 {
639     ARMCPU *cpu = env_archcpu(env);
640     int cur_el = arm_current_el(env);
641     unsigned int spsr_idx = aarch64_banked_spsr_index(cur_el);
642     uint32_t spsr = env->banked_spsr[spsr_idx];
643     int new_el;
644     bool return_to_aa64 = (spsr & PSTATE_nRW) == 0;
645 
646     aarch64_save_sp(env, cur_el);
647 
648     arm_clear_exclusive(env);
649 
650     /* We must squash the PSTATE.SS bit to zero unless both of the
651      * following hold:
652      *  1. debug exceptions are currently disabled
653      *  2. singlestep will be active in the EL we return to
654      * We check 1 here and 2 after we've done the pstate/cpsr write() to
655      * transition to the EL we're going to.
656      */
657     if (arm_generate_debug_exceptions(env)) {
658         spsr &= ~PSTATE_SS;
659     }
660 
661     /*
662      * FEAT_RME forbids return from EL3 with an invalid security state.
663      * We don't need an explicit check for FEAT_RME here because we enforce
664      * in scr_write() that you can't set the NSE bit without it.
665      */
666     if (cur_el == 3 && (env->cp15.scr_el3 & (SCR_NS | SCR_NSE)) == SCR_NSE) {
667         goto illegal_return;
668     }
669 
670     new_el = el_from_spsr(spsr);
671     if (new_el == -1) {
672         goto illegal_return;
673     }
674     if (new_el > cur_el || (new_el == 2 && !arm_is_el2_enabled(env))) {
675         /* Disallow return to an EL which is unimplemented or higher
676          * than the current one.
677          */
678         goto illegal_return;
679     }
680 
681     if (new_el != 0 && arm_el_is_aa64(env, new_el) != return_to_aa64) {
682         /* Return to an EL which is configured for a different register width */
683         goto illegal_return;
684     }
685 
686     if (!return_to_aa64 && !cpu_isar_feature(aa64_aa32, cpu)) {
687         /* Return to AArch32 when CPU is AArch64-only */
688         goto illegal_return;
689     }
690 
691     if (new_el == 1 && (arm_hcr_el2_eff(env) & HCR_TGE)) {
692         goto illegal_return;
693     }
694 
695     bql_lock();
696     arm_call_pre_el_change_hook(cpu);
697     bql_unlock();
698 
699     if (!return_to_aa64) {
700         env->aarch64 = false;
701         /* We do a raw CPSR write because aarch64_sync_64_to_32()
702          * will sort the register banks out for us, and we've already
703          * caught all the bad-mode cases in el_from_spsr().
704          */
705         cpsr_write_from_spsr_elx(env, spsr);
706         if (!arm_singlestep_active(env)) {
707             env->pstate &= ~PSTATE_SS;
708         }
709         aarch64_sync_64_to_32(env);
710 
711         if (spsr & CPSR_T) {
712             env->regs[15] = new_pc & ~0x1;
713         } else {
714             env->regs[15] = new_pc & ~0x3;
715         }
716         helper_rebuild_hflags_a32(env, new_el);
717         qemu_log_mask(CPU_LOG_INT, "Exception return from AArch64 EL%d to "
718                       "AArch32 EL%d PC 0x%" PRIx32 "\n",
719                       cur_el, new_el, env->regs[15]);
720     } else {
721         int tbii;
722 
723         env->aarch64 = true;
724         spsr &= aarch64_pstate_valid_mask(&cpu->isar);
725         pstate_write(env, spsr);
726         if (!arm_singlestep_active(env)) {
727             env->pstate &= ~PSTATE_SS;
728         }
729         aarch64_restore_sp(env, new_el);
730         helper_rebuild_hflags_a64(env, new_el);
731 
732         /*
733          * Apply TBI to the exception return address.  We had to delay this
734          * until after we selected the new EL, so that we could select the
735          * correct TBI+TBID bits.  This is made easier by waiting until after
736          * the hflags rebuild, since we can pull the composite TBII field
737          * from there.
738          */
739         tbii = EX_TBFLAG_A64(env->hflags, TBII);
740         if ((tbii >> extract64(new_pc, 55, 1)) & 1) {
741             /* TBI is enabled. */
742             int core_mmu_idx = arm_env_mmu_index(env);
743             if (regime_has_2_ranges(core_to_aa64_mmu_idx(core_mmu_idx))) {
744                 new_pc = sextract64(new_pc, 0, 56);
745             } else {
746                 new_pc = extract64(new_pc, 0, 56);
747             }
748         }
749         env->pc = new_pc;
750 
751         qemu_log_mask(CPU_LOG_INT, "Exception return from AArch64 EL%d to "
752                       "AArch64 EL%d PC 0x%" PRIx64 "\n",
753                       cur_el, new_el, env->pc);
754     }
755 
756     /*
757      * Note that cur_el can never be 0.  If new_el is 0, then
758      * el0_a64 is return_to_aa64, else el0_a64 is ignored.
759      */
760     aarch64_sve_change_el(env, cur_el, new_el, return_to_aa64);
761 
762     bql_lock();
763     arm_call_el_change_hook(cpu);
764     bql_unlock();
765 
766     return;
767 
768 illegal_return:
769     /* Illegal return events of various kinds have architecturally
770      * mandated behaviour:
771      * restore NZCV and DAIF from SPSR_ELx
772      * set PSTATE.IL
773      * restore PC from ELR_ELx
774      * no change to exception level, execution state or stack pointer
775      */
776     env->pstate |= PSTATE_IL;
777     env->pc = new_pc;
778     spsr &= PSTATE_NZCV | PSTATE_DAIF | PSTATE_ALLINT;
779     spsr |= pstate_read(env) & ~(PSTATE_NZCV | PSTATE_DAIF | PSTATE_ALLINT);
780     pstate_write(env, spsr);
781     if (!arm_singlestep_active(env)) {
782         env->pstate &= ~PSTATE_SS;
783     }
784     helper_rebuild_hflags_a64(env, cur_el);
785     qemu_log_mask(LOG_GUEST_ERROR, "Illegal exception return at EL%d: "
786                   "resuming execution at 0x%" PRIx64 "\n", cur_el, env->pc);
787 }
788 
789 void HELPER(dc_zva)(CPUARMState *env, uint64_t vaddr_in)
790 {
791     uintptr_t ra = GETPC();
792 
793     /*
794      * Implement DC ZVA, which zeroes a fixed-length block of memory.
795      * Note that we do not implement the (architecturally mandated)
796      * alignment fault for attempts to use this on Device memory
797      * (which matches the usual QEMU behaviour of not implementing either
798      * alignment faults or any memory attribute handling).
799      */
800     int blocklen = 4 << env_archcpu(env)->dcz_blocksize;
801     uint64_t vaddr = vaddr_in & ~(blocklen - 1);
802     int mmu_idx = arm_env_mmu_index(env);
803     void *mem;
804 
805     /*
806      * Trapless lookup.  In addition to actual invalid page, may
807      * return NULL for I/O, watchpoints, clean pages, etc.
808      */
809     mem = tlb_vaddr_to_host(env, vaddr, MMU_DATA_STORE, mmu_idx);
810 
811 #ifndef CONFIG_USER_ONLY
812     if (unlikely(!mem)) {
813         /*
814          * Trap if accessing an invalid page.  DC_ZVA requires that we supply
815          * the original pointer for an invalid page.  But watchpoints require
816          * that we probe the actual space.  So do both.
817          */
818         (void) probe_write(env, vaddr_in, 1, mmu_idx, ra);
819         mem = probe_write(env, vaddr, blocklen, mmu_idx, ra);
820 
821         if (unlikely(!mem)) {
822             /*
823              * The only remaining reason for mem == NULL is I/O.
824              * Just do a series of byte writes as the architecture demands.
825              */
826             for (int i = 0; i < blocklen; i++) {
827                 cpu_stb_mmuidx_ra(env, vaddr + i, 0, mmu_idx, ra);
828             }
829             return;
830         }
831     }
832 #endif
833 
834     set_helper_retaddr(ra);
835     memset(mem, 0, blocklen);
836     clear_helper_retaddr();
837 }
838 
839 void HELPER(unaligned_access)(CPUARMState *env, uint64_t addr,
840                               uint32_t access_type, uint32_t mmu_idx)
841 {
842     arm_cpu_do_unaligned_access(env_cpu(env), addr, access_type,
843                                 mmu_idx, GETPC());
844 }
845 
846 /* Memory operations (memset, memmove, memcpy) */
847 
848 /*
849  * Return true if the CPY* and SET* insns can execute; compare
850  * pseudocode CheckMOPSEnabled(), though we refactor it a little.
851  */
852 static bool mops_enabled(CPUARMState *env)
853 {
854     int el = arm_current_el(env);
855 
856     if (el < 2 &&
857         (arm_hcr_el2_eff(env) & (HCR_E2H | HCR_TGE)) != (HCR_E2H | HCR_TGE) &&
858         !(arm_hcrx_el2_eff(env) & HCRX_MSCEN)) {
859         return false;
860     }
861 
862     if (el == 0) {
863         if (!el_is_in_host(env, 0)) {
864             return env->cp15.sctlr_el[1] & SCTLR_MSCEN;
865         } else {
866             return env->cp15.sctlr_el[2] & SCTLR_MSCEN;
867         }
868     }
869     return true;
870 }
871 
872 static void check_mops_enabled(CPUARMState *env, uintptr_t ra)
873 {
874     if (!mops_enabled(env)) {
875         raise_exception_ra(env, EXCP_UDEF, syn_uncategorized(),
876                            exception_target_el(env), ra);
877     }
878 }
879 
880 /*
881  * Return the target exception level for an exception due
882  * to mismatched arguments in a FEAT_MOPS copy or set.
883  * Compare pseudocode MismatchedCpySetTargetEL()
884  */
885 static int mops_mismatch_exception_target_el(CPUARMState *env)
886 {
887     int el = arm_current_el(env);
888 
889     if (el > 1) {
890         return el;
891     }
892     if (el == 0 && (arm_hcr_el2_eff(env) & HCR_TGE)) {
893         return 2;
894     }
895     if (el == 1 && (arm_hcrx_el2_eff(env) & HCRX_MCE2)) {
896         return 2;
897     }
898     return 1;
899 }
900 
901 /*
902  * Check whether an M or E instruction was executed with a CF value
903  * indicating the wrong option for this implementation.
904  * Assumes we are always Option A.
905  */
906 static void check_mops_wrong_option(CPUARMState *env, uint32_t syndrome,
907                                     uintptr_t ra)
908 {
909     if (env->CF != 0) {
910         syndrome |= 1 << 17; /* Set the wrong-option bit */
911         raise_exception_ra(env, EXCP_UDEF, syndrome,
912                            mops_mismatch_exception_target_el(env), ra);
913     }
914 }
915 
916 /*
917  * Return the maximum number of bytes we can transfer starting at addr
918  * without crossing a page boundary.
919  */
920 static uint64_t page_limit(uint64_t addr)
921 {
922     return TARGET_PAGE_ALIGN(addr + 1) - addr;
923 }
924 
925 /*
926  * Return the number of bytes we can copy starting from addr and working
927  * backwards without crossing a page boundary.
928  */
929 static uint64_t page_limit_rev(uint64_t addr)
930 {
931     return (addr & ~TARGET_PAGE_MASK) + 1;
932 }
933 
934 /*
935  * Perform part of a memory set on an area of guest memory starting at
936  * toaddr (a dirty address) and extending for setsize bytes.
937  *
938  * Returns the number of bytes actually set, which might be less than
939  * setsize; the caller should loop until the whole set has been done.
940  * The caller should ensure that the guest registers are correct
941  * for the possibility that the first byte of the set encounters
942  * an exception or watchpoint. We guarantee not to take any faults
943  * for bytes other than the first.
944  */
945 static uint64_t set_step(CPUARMState *env, uint64_t toaddr,
946                          uint64_t setsize, uint32_t data, int memidx,
947                          uint32_t *mtedesc, uintptr_t ra)
948 {
949     void *mem;
950 
951     setsize = MIN(setsize, page_limit(toaddr));
952     if (*mtedesc) {
953         uint64_t mtesize = mte_mops_probe(env, toaddr, setsize, *mtedesc);
954         if (mtesize == 0) {
955             /* Trap, or not. All CPU state is up to date */
956             mte_check_fail(env, *mtedesc, toaddr, ra);
957             /* Continue, with no further MTE checks required */
958             *mtedesc = 0;
959         } else {
960             /* Advance to the end, or to the tag mismatch */
961             setsize = MIN(setsize, mtesize);
962         }
963     }
964 
965     toaddr = useronly_clean_ptr(toaddr);
966     /*
967      * Trapless lookup: returns NULL for invalid page, I/O,
968      * watchpoints, clean pages, etc.
969      */
970     mem = tlb_vaddr_to_host(env, toaddr, MMU_DATA_STORE, memidx);
971 
972 #ifndef CONFIG_USER_ONLY
973     if (unlikely(!mem)) {
974         /*
975          * Slow-path: just do one byte write. This will handle the
976          * watchpoint, invalid page, etc handling correctly.
977          * For clean code pages, the next iteration will see
978          * the page dirty and will use the fast path.
979          */
980         cpu_stb_mmuidx_ra(env, toaddr, data, memidx, ra);
981         return 1;
982     }
983 #endif
984     /* Easy case: just memset the host memory */
985     set_helper_retaddr(ra);
986     memset(mem, data, setsize);
987     clear_helper_retaddr();
988     return setsize;
989 }
990 
991 /*
992  * Similar, but setting tags. The architecture requires us to do this
993  * in 16-byte chunks. SETP accesses are not tag checked; they set
994  * the tags.
995  */
996 static uint64_t set_step_tags(CPUARMState *env, uint64_t toaddr,
997                               uint64_t setsize, uint32_t data, int memidx,
998                               uint32_t *mtedesc, uintptr_t ra)
999 {
1000     void *mem;
1001     uint64_t cleanaddr;
1002 
1003     setsize = MIN(setsize, page_limit(toaddr));
1004 
1005     cleanaddr = useronly_clean_ptr(toaddr);
1006     /*
1007      * Trapless lookup: returns NULL for invalid page, I/O,
1008      * watchpoints, clean pages, etc.
1009      */
1010     mem = tlb_vaddr_to_host(env, cleanaddr, MMU_DATA_STORE, memidx);
1011 
1012 #ifndef CONFIG_USER_ONLY
1013     if (unlikely(!mem)) {
1014         /*
1015          * Slow-path: just do one write. This will handle the
1016          * watchpoint, invalid page, etc handling correctly.
1017          * The architecture requires that we do 16 bytes at a time,
1018          * and we know both ptr and size are 16 byte aligned.
1019          * For clean code pages, the next iteration will see
1020          * the page dirty and will use the fast path.
1021          */
1022         uint64_t repldata = data * 0x0101010101010101ULL;
1023         MemOpIdx oi16 = make_memop_idx(MO_TE | MO_128, memidx);
1024         cpu_st16_mmu(env, toaddr, int128_make128(repldata, repldata), oi16, ra);
1025         mte_mops_set_tags(env, toaddr, 16, *mtedesc);
1026         return 16;
1027     }
1028 #endif
1029     /* Easy case: just memset the host memory */
1030     set_helper_retaddr(ra);
1031     memset(mem, data, setsize);
1032     clear_helper_retaddr();
1033     mte_mops_set_tags(env, toaddr, setsize, *mtedesc);
1034     return setsize;
1035 }
1036 
1037 typedef uint64_t StepFn(CPUARMState *env, uint64_t toaddr,
1038                         uint64_t setsize, uint32_t data,
1039                         int memidx, uint32_t *mtedesc, uintptr_t ra);
1040 
1041 /* Extract register numbers from a MOPS exception syndrome value */
1042 static int mops_destreg(uint32_t syndrome)
1043 {
1044     return extract32(syndrome, 10, 5);
1045 }
1046 
1047 static int mops_srcreg(uint32_t syndrome)
1048 {
1049     return extract32(syndrome, 5, 5);
1050 }
1051 
1052 static int mops_sizereg(uint32_t syndrome)
1053 {
1054     return extract32(syndrome, 0, 5);
1055 }
1056 
1057 /*
1058  * Return true if TCMA and TBI bits mean we need to do MTE checks.
1059  * We only need to do this once per MOPS insn, not for every page.
1060  */
1061 static bool mte_checks_needed(uint64_t ptr, uint32_t desc)
1062 {
1063     int bit55 = extract64(ptr, 55, 1);
1064 
1065     /*
1066      * Note that tbi_check() returns true for "access checked" but
1067      * tcma_check() returns true for "access unchecked".
1068      */
1069     if (!tbi_check(desc, bit55)) {
1070         return false;
1071     }
1072     return !tcma_check(desc, bit55, allocation_tag_from_addr(ptr));
1073 }
1074 
1075 /* Take an exception if the SETG addr/size are not granule aligned */
1076 static void check_setg_alignment(CPUARMState *env, uint64_t ptr, uint64_t size,
1077                                  uint32_t memidx, uintptr_t ra)
1078 {
1079     if ((size != 0 && !QEMU_IS_ALIGNED(ptr, TAG_GRANULE)) ||
1080         !QEMU_IS_ALIGNED(size, TAG_GRANULE)) {
1081         arm_cpu_do_unaligned_access(env_cpu(env), ptr, MMU_DATA_STORE,
1082                                     memidx, ra);
1083 
1084     }
1085 }
1086 
1087 static uint64_t arm_reg_or_xzr(CPUARMState *env, int reg)
1088 {
1089     /*
1090      * Runtime equivalent of cpu_reg() -- return the CPU register value,
1091      * for contexts when index 31 means XZR (not SP).
1092      */
1093     return reg == 31 ? 0 : env->xregs[reg];
1094 }
1095 
1096 /*
1097  * For the Memory Set operation, our implementation chooses
1098  * always to use "option A", where we update Xd to the final
1099  * address in the SETP insn, and set Xn to be -(bytes remaining).
1100  * On SETM and SETE insns we only need update Xn.
1101  *
1102  * @env: CPU
1103  * @syndrome: syndrome value for mismatch exceptions
1104  * (also contains the register numbers we need to use)
1105  * @mtedesc: MTE descriptor word
1106  * @stepfn: function which does a single part of the set operation
1107  * @is_setg: true if this is the tag-setting SETG variant
1108  */
1109 static void do_setp(CPUARMState *env, uint32_t syndrome, uint32_t mtedesc,
1110                     StepFn *stepfn, bool is_setg, uintptr_t ra)
1111 {
1112     /* Prologue: we choose to do up to the next page boundary */
1113     int rd = mops_destreg(syndrome);
1114     int rs = mops_srcreg(syndrome);
1115     int rn = mops_sizereg(syndrome);
1116     uint8_t data = arm_reg_or_xzr(env, rs);
1117     uint32_t memidx = FIELD_EX32(mtedesc, MTEDESC, MIDX);
1118     uint64_t toaddr = env->xregs[rd];
1119     uint64_t setsize = env->xregs[rn];
1120     uint64_t stagesetsize, step;
1121 
1122     check_mops_enabled(env, ra);
1123 
1124     if (setsize > INT64_MAX) {
1125         setsize = INT64_MAX;
1126         if (is_setg) {
1127             setsize &= ~0xf;
1128         }
1129     }
1130 
1131     if (unlikely(is_setg)) {
1132         check_setg_alignment(env, toaddr, setsize, memidx, ra);
1133     } else if (!mte_checks_needed(toaddr, mtedesc)) {
1134         mtedesc = 0;
1135     }
1136 
1137     stagesetsize = MIN(setsize, page_limit(toaddr));
1138     while (stagesetsize) {
1139         env->xregs[rd] = toaddr;
1140         env->xregs[rn] = setsize;
1141         step = stepfn(env, toaddr, stagesetsize, data, memidx, &mtedesc, ra);
1142         toaddr += step;
1143         setsize -= step;
1144         stagesetsize -= step;
1145     }
1146     /* Insn completed, so update registers to the Option A format */
1147     env->xregs[rd] = toaddr + setsize;
1148     env->xregs[rn] = -setsize;
1149 
1150     /* Set NZCV = 0000 to indicate we are an Option A implementation */
1151     env->NF = 0;
1152     env->ZF = 1; /* our env->ZF encoding is inverted */
1153     env->CF = 0;
1154     env->VF = 0;
1155 }
1156 
1157 void HELPER(setp)(CPUARMState *env, uint32_t syndrome, uint32_t mtedesc)
1158 {
1159     do_setp(env, syndrome, mtedesc, set_step, false, GETPC());
1160 }
1161 
1162 void HELPER(setgp)(CPUARMState *env, uint32_t syndrome, uint32_t mtedesc)
1163 {
1164     do_setp(env, syndrome, mtedesc, set_step_tags, true, GETPC());
1165 }
1166 
1167 static void do_setm(CPUARMState *env, uint32_t syndrome, uint32_t mtedesc,
1168                     StepFn *stepfn, bool is_setg, uintptr_t ra)
1169 {
1170     /* Main: we choose to do all the full-page chunks */
1171     CPUState *cs = env_cpu(env);
1172     int rd = mops_destreg(syndrome);
1173     int rs = mops_srcreg(syndrome);
1174     int rn = mops_sizereg(syndrome);
1175     uint8_t data = arm_reg_or_xzr(env, rs);
1176     uint64_t toaddr = env->xregs[rd] + env->xregs[rn];
1177     uint64_t setsize = -env->xregs[rn];
1178     uint32_t memidx = FIELD_EX32(mtedesc, MTEDESC, MIDX);
1179     uint64_t step, stagesetsize;
1180 
1181     check_mops_enabled(env, ra);
1182 
1183     /*
1184      * We're allowed to NOP out "no data to copy" before the consistency
1185      * checks; we choose to do so.
1186      */
1187     if (env->xregs[rn] == 0) {
1188         return;
1189     }
1190 
1191     check_mops_wrong_option(env, syndrome, ra);
1192 
1193     /*
1194      * Our implementation will work fine even if we have an unaligned
1195      * destination address, and because we update Xn every time around
1196      * the loop below and the return value from stepfn() may be less
1197      * than requested, we might find toaddr is unaligned. So we don't
1198      * have an IMPDEF check for alignment here.
1199      */
1200 
1201     if (unlikely(is_setg)) {
1202         check_setg_alignment(env, toaddr, setsize, memidx, ra);
1203     } else if (!mte_checks_needed(toaddr, mtedesc)) {
1204         mtedesc = 0;
1205     }
1206 
1207     /* Do the actual memset: we leave the last partial page to SETE */
1208     stagesetsize = setsize & TARGET_PAGE_MASK;
1209     while (stagesetsize > 0) {
1210         step = stepfn(env, toaddr, stagesetsize, data, memidx, &mtedesc, ra);
1211         toaddr += step;
1212         setsize -= step;
1213         stagesetsize -= step;
1214         env->xregs[rn] = -setsize;
1215         if (stagesetsize > 0 && unlikely(cpu_loop_exit_requested(cs))) {
1216             cpu_loop_exit_restore(cs, ra);
1217         }
1218     }
1219 }
1220 
1221 void HELPER(setm)(CPUARMState *env, uint32_t syndrome, uint32_t mtedesc)
1222 {
1223     do_setm(env, syndrome, mtedesc, set_step, false, GETPC());
1224 }
1225 
1226 void HELPER(setgm)(CPUARMState *env, uint32_t syndrome, uint32_t mtedesc)
1227 {
1228     do_setm(env, syndrome, mtedesc, set_step_tags, true, GETPC());
1229 }
1230 
1231 static void do_sete(CPUARMState *env, uint32_t syndrome, uint32_t mtedesc,
1232                     StepFn *stepfn, bool is_setg, uintptr_t ra)
1233 {
1234     /* Epilogue: do the last partial page */
1235     int rd = mops_destreg(syndrome);
1236     int rs = mops_srcreg(syndrome);
1237     int rn = mops_sizereg(syndrome);
1238     uint8_t data = arm_reg_or_xzr(env, rs);
1239     uint64_t toaddr = env->xregs[rd] + env->xregs[rn];
1240     uint64_t setsize = -env->xregs[rn];
1241     uint32_t memidx = FIELD_EX32(mtedesc, MTEDESC, MIDX);
1242     uint64_t step;
1243 
1244     check_mops_enabled(env, ra);
1245 
1246     /*
1247      * We're allowed to NOP out "no data to copy" before the consistency
1248      * checks; we choose to do so.
1249      */
1250     if (setsize == 0) {
1251         return;
1252     }
1253 
1254     check_mops_wrong_option(env, syndrome, ra);
1255 
1256     /*
1257      * Our implementation has no address alignment requirements, but
1258      * we do want to enforce the "less than a page" size requirement,
1259      * so we don't need to have the "check for interrupts" here.
1260      */
1261     if (setsize >= TARGET_PAGE_SIZE) {
1262         raise_exception_ra(env, EXCP_UDEF, syndrome,
1263                            mops_mismatch_exception_target_el(env), ra);
1264     }
1265 
1266     if (unlikely(is_setg)) {
1267         check_setg_alignment(env, toaddr, setsize, memidx, ra);
1268     } else if (!mte_checks_needed(toaddr, mtedesc)) {
1269         mtedesc = 0;
1270     }
1271 
1272     /* Do the actual memset */
1273     while (setsize > 0) {
1274         step = stepfn(env, toaddr, setsize, data, memidx, &mtedesc, ra);
1275         toaddr += step;
1276         setsize -= step;
1277         env->xregs[rn] = -setsize;
1278     }
1279 }
1280 
1281 void HELPER(sete)(CPUARMState *env, uint32_t syndrome, uint32_t mtedesc)
1282 {
1283     do_sete(env, syndrome, mtedesc, set_step, false, GETPC());
1284 }
1285 
1286 void HELPER(setge)(CPUARMState *env, uint32_t syndrome, uint32_t mtedesc)
1287 {
1288     do_sete(env, syndrome, mtedesc, set_step_tags, true, GETPC());
1289 }
1290 
1291 /*
1292  * Perform part of a memory copy from the guest memory at fromaddr
1293  * and extending for copysize bytes, to the guest memory at
1294  * toaddr. Both addresses are dirty.
1295  *
1296  * Returns the number of bytes actually set, which might be less than
1297  * copysize; the caller should loop until the whole copy has been done.
1298  * The caller should ensure that the guest registers are correct
1299  * for the possibility that the first byte of the copy encounters
1300  * an exception or watchpoint. We guarantee not to take any faults
1301  * for bytes other than the first.
1302  */
1303 static uint64_t copy_step(CPUARMState *env, uint64_t toaddr, uint64_t fromaddr,
1304                           uint64_t copysize, int wmemidx, int rmemidx,
1305                           uint32_t *wdesc, uint32_t *rdesc, uintptr_t ra)
1306 {
1307     void *rmem;
1308     void *wmem;
1309 
1310     /* Don't cross a page boundary on either source or destination */
1311     copysize = MIN(copysize, page_limit(toaddr));
1312     copysize = MIN(copysize, page_limit(fromaddr));
1313     /*
1314      * Handle MTE tag checks: either handle the tag mismatch for byte 0,
1315      * or else copy up to but not including the byte with the mismatch.
1316      */
1317     if (*rdesc) {
1318         uint64_t mtesize = mte_mops_probe(env, fromaddr, copysize, *rdesc);
1319         if (mtesize == 0) {
1320             mte_check_fail(env, *rdesc, fromaddr, ra);
1321             *rdesc = 0;
1322         } else {
1323             copysize = MIN(copysize, mtesize);
1324         }
1325     }
1326     if (*wdesc) {
1327         uint64_t mtesize = mte_mops_probe(env, toaddr, copysize, *wdesc);
1328         if (mtesize == 0) {
1329             mte_check_fail(env, *wdesc, toaddr, ra);
1330             *wdesc = 0;
1331         } else {
1332             copysize = MIN(copysize, mtesize);
1333         }
1334     }
1335 
1336     toaddr = useronly_clean_ptr(toaddr);
1337     fromaddr = useronly_clean_ptr(fromaddr);
1338     /* Trapless lookup of whether we can get a host memory pointer */
1339     wmem = tlb_vaddr_to_host(env, toaddr, MMU_DATA_STORE, wmemidx);
1340     rmem = tlb_vaddr_to_host(env, fromaddr, MMU_DATA_LOAD, rmemidx);
1341 
1342 #ifndef CONFIG_USER_ONLY
1343     /*
1344      * If we don't have host memory for both source and dest then just
1345      * do a single byte copy. This will handle watchpoints, invalid pages,
1346      * etc correctly. For clean code pages, the next iteration will see
1347      * the page dirty and will use the fast path.
1348      */
1349     if (unlikely(!rmem || !wmem)) {
1350         uint8_t byte;
1351         if (rmem) {
1352             byte = *(uint8_t *)rmem;
1353         } else {
1354             byte = cpu_ldub_mmuidx_ra(env, fromaddr, rmemidx, ra);
1355         }
1356         if (wmem) {
1357             *(uint8_t *)wmem = byte;
1358         } else {
1359             cpu_stb_mmuidx_ra(env, toaddr, byte, wmemidx, ra);
1360         }
1361         return 1;
1362     }
1363 #endif
1364     /* Easy case: just memmove the host memory */
1365     set_helper_retaddr(ra);
1366     memmove(wmem, rmem, copysize);
1367     clear_helper_retaddr();
1368     return copysize;
1369 }
1370 
1371 /*
1372  * Do part of a backwards memory copy. Here toaddr and fromaddr point
1373  * to the *last* byte to be copied.
1374  */
1375 static uint64_t copy_step_rev(CPUARMState *env, uint64_t toaddr,
1376                               uint64_t fromaddr,
1377                               uint64_t copysize, int wmemidx, int rmemidx,
1378                               uint32_t *wdesc, uint32_t *rdesc, uintptr_t ra)
1379 {
1380     void *rmem;
1381     void *wmem;
1382 
1383     /* Don't cross a page boundary on either source or destination */
1384     copysize = MIN(copysize, page_limit_rev(toaddr));
1385     copysize = MIN(copysize, page_limit_rev(fromaddr));
1386 
1387     /*
1388      * Handle MTE tag checks: either handle the tag mismatch for byte 0,
1389      * or else copy up to but not including the byte with the mismatch.
1390      */
1391     if (*rdesc) {
1392         uint64_t mtesize = mte_mops_probe_rev(env, fromaddr, copysize, *rdesc);
1393         if (mtesize == 0) {
1394             mte_check_fail(env, *rdesc, fromaddr, ra);
1395             *rdesc = 0;
1396         } else {
1397             copysize = MIN(copysize, mtesize);
1398         }
1399     }
1400     if (*wdesc) {
1401         uint64_t mtesize = mte_mops_probe_rev(env, toaddr, copysize, *wdesc);
1402         if (mtesize == 0) {
1403             mte_check_fail(env, *wdesc, toaddr, ra);
1404             *wdesc = 0;
1405         } else {
1406             copysize = MIN(copysize, mtesize);
1407         }
1408     }
1409 
1410     toaddr = useronly_clean_ptr(toaddr);
1411     fromaddr = useronly_clean_ptr(fromaddr);
1412     /* Trapless lookup of whether we can get a host memory pointer */
1413     wmem = tlb_vaddr_to_host(env, toaddr, MMU_DATA_STORE, wmemidx);
1414     rmem = tlb_vaddr_to_host(env, fromaddr, MMU_DATA_LOAD, rmemidx);
1415 
1416 #ifndef CONFIG_USER_ONLY
1417     /*
1418      * If we don't have host memory for both source and dest then just
1419      * do a single byte copy. This will handle watchpoints, invalid pages,
1420      * etc correctly. For clean code pages, the next iteration will see
1421      * the page dirty and will use the fast path.
1422      */
1423     if (unlikely(!rmem || !wmem)) {
1424         uint8_t byte;
1425         if (rmem) {
1426             byte = *(uint8_t *)rmem;
1427         } else {
1428             byte = cpu_ldub_mmuidx_ra(env, fromaddr, rmemidx, ra);
1429         }
1430         if (wmem) {
1431             *(uint8_t *)wmem = byte;
1432         } else {
1433             cpu_stb_mmuidx_ra(env, toaddr, byte, wmemidx, ra);
1434         }
1435         return 1;
1436     }
1437 #endif
1438     /*
1439      * Easy case: just memmove the host memory. Note that wmem and
1440      * rmem here point to the *last* byte to copy.
1441      */
1442     set_helper_retaddr(ra);
1443     memmove(wmem - (copysize - 1), rmem - (copysize - 1), copysize);
1444     clear_helper_retaddr();
1445     return copysize;
1446 }
1447 
1448 /*
1449  * for the Memory Copy operation, our implementation chooses always
1450  * to use "option A", where we update Xd and Xs to the final addresses
1451  * in the CPYP insn, and then in CPYM and CPYE only need to update Xn.
1452  *
1453  * @env: CPU
1454  * @syndrome: syndrome value for mismatch exceptions
1455  * (also contains the register numbers we need to use)
1456  * @wdesc: MTE descriptor for the writes (destination)
1457  * @rdesc: MTE descriptor for the reads (source)
1458  * @move: true if this is CPY (memmove), false for CPYF (memcpy forwards)
1459  */
1460 static void do_cpyp(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
1461                     uint32_t rdesc, uint32_t move, uintptr_t ra)
1462 {
1463     int rd = mops_destreg(syndrome);
1464     int rs = mops_srcreg(syndrome);
1465     int rn = mops_sizereg(syndrome);
1466     uint32_t rmemidx = FIELD_EX32(rdesc, MTEDESC, MIDX);
1467     uint32_t wmemidx = FIELD_EX32(wdesc, MTEDESC, MIDX);
1468     bool forwards = true;
1469     uint64_t toaddr = env->xregs[rd];
1470     uint64_t fromaddr = env->xregs[rs];
1471     uint64_t copysize = env->xregs[rn];
1472     uint64_t stagecopysize, step;
1473 
1474     check_mops_enabled(env, ra);
1475 
1476 
1477     if (move) {
1478         /*
1479          * Copy backwards if necessary. The direction for a non-overlapping
1480          * copy is IMPDEF; we choose forwards.
1481          */
1482         if (copysize > 0x007FFFFFFFFFFFFFULL) {
1483             copysize = 0x007FFFFFFFFFFFFFULL;
1484         }
1485         uint64_t fs = extract64(fromaddr, 0, 56);
1486         uint64_t ts = extract64(toaddr, 0, 56);
1487         uint64_t fe = extract64(fromaddr + copysize, 0, 56);
1488 
1489         if (fs < ts && fe > ts) {
1490             forwards = false;
1491         }
1492     } else {
1493         if (copysize > INT64_MAX) {
1494             copysize = INT64_MAX;
1495         }
1496     }
1497 
1498     if (!mte_checks_needed(fromaddr, rdesc)) {
1499         rdesc = 0;
1500     }
1501     if (!mte_checks_needed(toaddr, wdesc)) {
1502         wdesc = 0;
1503     }
1504 
1505     if (forwards) {
1506         stagecopysize = MIN(copysize, page_limit(toaddr));
1507         stagecopysize = MIN(stagecopysize, page_limit(fromaddr));
1508         while (stagecopysize) {
1509             env->xregs[rd] = toaddr;
1510             env->xregs[rs] = fromaddr;
1511             env->xregs[rn] = copysize;
1512             step = copy_step(env, toaddr, fromaddr, stagecopysize,
1513                              wmemidx, rmemidx, &wdesc, &rdesc, ra);
1514             toaddr += step;
1515             fromaddr += step;
1516             copysize -= step;
1517             stagecopysize -= step;
1518         }
1519         /* Insn completed, so update registers to the Option A format */
1520         env->xregs[rd] = toaddr + copysize;
1521         env->xregs[rs] = fromaddr + copysize;
1522         env->xregs[rn] = -copysize;
1523     } else {
1524         /*
1525          * In a reverse copy the to and from addrs in Xs and Xd are the start
1526          * of the range, but it's more convenient for us to work with pointers
1527          * to the last byte being copied.
1528          */
1529         toaddr += copysize - 1;
1530         fromaddr += copysize - 1;
1531         stagecopysize = MIN(copysize, page_limit_rev(toaddr));
1532         stagecopysize = MIN(stagecopysize, page_limit_rev(fromaddr));
1533         while (stagecopysize) {
1534             env->xregs[rn] = copysize;
1535             step = copy_step_rev(env, toaddr, fromaddr, stagecopysize,
1536                                  wmemidx, rmemidx, &wdesc, &rdesc, ra);
1537             copysize -= step;
1538             stagecopysize -= step;
1539             toaddr -= step;
1540             fromaddr -= step;
1541         }
1542         /*
1543          * Insn completed, so update registers to the Option A format.
1544          * For a reverse copy this is no different to the CPYP input format.
1545          */
1546         env->xregs[rn] = copysize;
1547     }
1548 
1549     /* Set NZCV = 0000 to indicate we are an Option A implementation */
1550     env->NF = 0;
1551     env->ZF = 1; /* our env->ZF encoding is inverted */
1552     env->CF = 0;
1553     env->VF = 0;
1554 }
1555 
1556 void HELPER(cpyp)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
1557                   uint32_t rdesc)
1558 {
1559     do_cpyp(env, syndrome, wdesc, rdesc, true, GETPC());
1560 }
1561 
1562 void HELPER(cpyfp)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
1563                    uint32_t rdesc)
1564 {
1565     do_cpyp(env, syndrome, wdesc, rdesc, false, GETPC());
1566 }
1567 
1568 static void do_cpym(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
1569                     uint32_t rdesc, uint32_t move, uintptr_t ra)
1570 {
1571     /* Main: we choose to copy until less than a page remaining */
1572     CPUState *cs = env_cpu(env);
1573     int rd = mops_destreg(syndrome);
1574     int rs = mops_srcreg(syndrome);
1575     int rn = mops_sizereg(syndrome);
1576     uint32_t rmemidx = FIELD_EX32(rdesc, MTEDESC, MIDX);
1577     uint32_t wmemidx = FIELD_EX32(wdesc, MTEDESC, MIDX);
1578     bool forwards = true;
1579     uint64_t toaddr, fromaddr, copysize, step;
1580 
1581     check_mops_enabled(env, ra);
1582 
1583     /* We choose to NOP out "no data to copy" before consistency checks */
1584     if (env->xregs[rn] == 0) {
1585         return;
1586     }
1587 
1588     check_mops_wrong_option(env, syndrome, ra);
1589 
1590     if (move) {
1591         forwards = (int64_t)env->xregs[rn] < 0;
1592     }
1593 
1594     if (forwards) {
1595         toaddr = env->xregs[rd] + env->xregs[rn];
1596         fromaddr = env->xregs[rs] + env->xregs[rn];
1597         copysize = -env->xregs[rn];
1598     } else {
1599         copysize = env->xregs[rn];
1600         /* This toaddr and fromaddr point to the *last* byte to copy */
1601         toaddr = env->xregs[rd] + copysize - 1;
1602         fromaddr = env->xregs[rs] + copysize - 1;
1603     }
1604 
1605     if (!mte_checks_needed(fromaddr, rdesc)) {
1606         rdesc = 0;
1607     }
1608     if (!mte_checks_needed(toaddr, wdesc)) {
1609         wdesc = 0;
1610     }
1611 
1612     /* Our implementation has no particular parameter requirements for CPYM */
1613 
1614     /* Do the actual memmove */
1615     if (forwards) {
1616         while (copysize >= TARGET_PAGE_SIZE) {
1617             step = copy_step(env, toaddr, fromaddr, copysize,
1618                              wmemidx, rmemidx, &wdesc, &rdesc, ra);
1619             toaddr += step;
1620             fromaddr += step;
1621             copysize -= step;
1622             env->xregs[rn] = -copysize;
1623             if (copysize >= TARGET_PAGE_SIZE &&
1624                 unlikely(cpu_loop_exit_requested(cs))) {
1625                 cpu_loop_exit_restore(cs, ra);
1626             }
1627         }
1628     } else {
1629         while (copysize >= TARGET_PAGE_SIZE) {
1630             step = copy_step_rev(env, toaddr, fromaddr, copysize,
1631                                  wmemidx, rmemidx, &wdesc, &rdesc, ra);
1632             toaddr -= step;
1633             fromaddr -= step;
1634             copysize -= step;
1635             env->xregs[rn] = copysize;
1636             if (copysize >= TARGET_PAGE_SIZE &&
1637                 unlikely(cpu_loop_exit_requested(cs))) {
1638                 cpu_loop_exit_restore(cs, ra);
1639             }
1640         }
1641     }
1642 }
1643 
1644 void HELPER(cpym)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
1645                   uint32_t rdesc)
1646 {
1647     do_cpym(env, syndrome, wdesc, rdesc, true, GETPC());
1648 }
1649 
1650 void HELPER(cpyfm)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
1651                    uint32_t rdesc)
1652 {
1653     do_cpym(env, syndrome, wdesc, rdesc, false, GETPC());
1654 }
1655 
1656 static void do_cpye(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
1657                     uint32_t rdesc, uint32_t move, uintptr_t ra)
1658 {
1659     /* Epilogue: do the last partial page */
1660     int rd = mops_destreg(syndrome);
1661     int rs = mops_srcreg(syndrome);
1662     int rn = mops_sizereg(syndrome);
1663     uint32_t rmemidx = FIELD_EX32(rdesc, MTEDESC, MIDX);
1664     uint32_t wmemidx = FIELD_EX32(wdesc, MTEDESC, MIDX);
1665     bool forwards = true;
1666     uint64_t toaddr, fromaddr, copysize, step;
1667 
1668     check_mops_enabled(env, ra);
1669 
1670     /* We choose to NOP out "no data to copy" before consistency checks */
1671     if (env->xregs[rn] == 0) {
1672         return;
1673     }
1674 
1675     check_mops_wrong_option(env, syndrome, ra);
1676 
1677     if (move) {
1678         forwards = (int64_t)env->xregs[rn] < 0;
1679     }
1680 
1681     if (forwards) {
1682         toaddr = env->xregs[rd] + env->xregs[rn];
1683         fromaddr = env->xregs[rs] + env->xregs[rn];
1684         copysize = -env->xregs[rn];
1685     } else {
1686         copysize = env->xregs[rn];
1687         /* This toaddr and fromaddr point to the *last* byte to copy */
1688         toaddr = env->xregs[rd] + copysize - 1;
1689         fromaddr = env->xregs[rs] + copysize - 1;
1690     }
1691 
1692     if (!mte_checks_needed(fromaddr, rdesc)) {
1693         rdesc = 0;
1694     }
1695     if (!mte_checks_needed(toaddr, wdesc)) {
1696         wdesc = 0;
1697     }
1698 
1699     /* Check the size; we don't want to have do a check-for-interrupts */
1700     if (copysize >= TARGET_PAGE_SIZE) {
1701         raise_exception_ra(env, EXCP_UDEF, syndrome,
1702                            mops_mismatch_exception_target_el(env), ra);
1703     }
1704 
1705     /* Do the actual memmove */
1706     if (forwards) {
1707         while (copysize > 0) {
1708             step = copy_step(env, toaddr, fromaddr, copysize,
1709                              wmemidx, rmemidx, &wdesc, &rdesc, ra);
1710             toaddr += step;
1711             fromaddr += step;
1712             copysize -= step;
1713             env->xregs[rn] = -copysize;
1714         }
1715     } else {
1716         while (copysize > 0) {
1717             step = copy_step_rev(env, toaddr, fromaddr, copysize,
1718                                  wmemidx, rmemidx, &wdesc, &rdesc, ra);
1719             toaddr -= step;
1720             fromaddr -= step;
1721             copysize -= step;
1722             env->xregs[rn] = copysize;
1723         }
1724     }
1725 }
1726 
1727 void HELPER(cpye)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
1728                   uint32_t rdesc)
1729 {
1730     do_cpye(env, syndrome, wdesc, rdesc, true, GETPC());
1731 }
1732 
1733 void HELPER(cpyfe)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
1734                    uint32_t rdesc)
1735 {
1736     do_cpye(env, syndrome, wdesc, rdesc, false, GETPC());
1737 }
1738 
1739 static bool is_guarded_page(CPUARMState *env, target_ulong addr, uintptr_t ra)
1740 {
1741 #ifdef CONFIG_USER_ONLY
1742     return page_get_flags(addr) & PAGE_BTI;
1743 #else
1744     CPUTLBEntryFull *full;
1745     void *host;
1746     int mmu_idx = cpu_mmu_index(env_cpu(env), true);
1747     int flags = probe_access_full(env, addr, 0, MMU_INST_FETCH, mmu_idx,
1748                                   false, &host, &full, ra);
1749 
1750     assert(!(flags & TLB_INVALID_MASK));
1751     return full->extra.arm.guarded;
1752 #endif
1753 }
1754 
1755 void HELPER(guarded_page_check)(CPUARMState *env)
1756 {
1757     /*
1758      * We have already verified that bti is enabled, and that the
1759      * instruction at PC is not ok for BTYPE.  This is always at
1760      * the beginning of a block, so PC is always up-to-date and
1761      * no unwind is required.
1762      */
1763     if (is_guarded_page(env, env->pc, 0)) {
1764         raise_exception(env, EXCP_UDEF, syn_btitrap(env->btype),
1765                         exception_target_el(env));
1766     }
1767 }
1768 
1769 void HELPER(guarded_page_br)(CPUARMState *env, target_ulong pc)
1770 {
1771     /*
1772      * We have already checked for branch via x16 and x17.
1773      * What remains for choosing BTYPE is checking for a guarded page.
1774      */
1775     env->btype = is_guarded_page(env, pc, GETPC()) ? 3 : 1;
1776 }
1777