xref: /openbmc/qemu/target/arm/tcg/hflags.c (revision e6203636)
1 /*
2  * ARM hflags
3  *
4  * This code is licensed under the GNU GPL v2 or later.
5  *
6  * SPDX-License-Identifier: GPL-2.0-or-later
7  */
8 #include "qemu/osdep.h"
9 #include "cpu.h"
10 #include "internals.h"
11 #include "cpu-features.h"
12 #include "exec/helper-proto.h"
13 #include "cpregs.h"
14 
15 static inline bool fgt_svc(CPUARMState *env, int el)
16 {
17     /*
18      * Assuming fine-grained-traps are active, return true if we
19      * should be trapping on SVC instructions. Only AArch64 can
20      * trap on an SVC at EL1, but we don't need to special-case this
21      * because if this is AArch32 EL1 then arm_fgt_active() is false.
22      * We also know el is 0 or 1.
23      */
24     return el == 0 ?
25         FIELD_EX64(env->cp15.fgt_exec[FGTREG_HFGITR], HFGITR_EL2, SVC_EL0) :
26         FIELD_EX64(env->cp15.fgt_exec[FGTREG_HFGITR], HFGITR_EL2, SVC_EL1);
27 }
28 
29 /* Return true if memory alignment should be enforced. */
30 static bool aprofile_require_alignment(CPUARMState *env, int el, uint64_t sctlr)
31 {
32 #ifdef CONFIG_USER_ONLY
33     return false;
34 #else
35     /* Check the alignment enable bit. */
36     if (sctlr & SCTLR_A) {
37         return true;
38     }
39 
40     /*
41      * If translation is disabled, then the default memory type is
42      * Device(-nGnRnE) instead of Normal, which requires that alignment
43      * be enforced.  Since this affects all ram, it is most efficient
44      * to handle this during translation.
45      */
46     if (sctlr & SCTLR_M) {
47         /* Translation enabled: memory type in PTE via MAIR_ELx. */
48         return false;
49     }
50     if (el < 2 && (arm_hcr_el2_eff(env) & (HCR_DC | HCR_VM))) {
51         /* Stage 2 translation enabled: memory type in PTE. */
52         return false;
53     }
54     return true;
55 #endif
56 }
57 
58 static CPUARMTBFlags rebuild_hflags_common(CPUARMState *env, int fp_el,
59                                            ARMMMUIdx mmu_idx,
60                                            CPUARMTBFlags flags)
61 {
62     DP_TBFLAG_ANY(flags, FPEXC_EL, fp_el);
63     DP_TBFLAG_ANY(flags, MMUIDX, arm_to_core_mmu_idx(mmu_idx));
64 
65     if (arm_singlestep_active(env)) {
66         DP_TBFLAG_ANY(flags, SS_ACTIVE, 1);
67     }
68 
69     return flags;
70 }
71 
72 static CPUARMTBFlags rebuild_hflags_common_32(CPUARMState *env, int fp_el,
73                                               ARMMMUIdx mmu_idx,
74                                               CPUARMTBFlags flags)
75 {
76     bool sctlr_b = arm_sctlr_b(env);
77 
78     if (sctlr_b) {
79         DP_TBFLAG_A32(flags, SCTLR__B, 1);
80     }
81     if (arm_cpu_data_is_big_endian_a32(env, sctlr_b)) {
82         DP_TBFLAG_ANY(flags, BE_DATA, 1);
83     }
84     DP_TBFLAG_A32(flags, NS, !access_secure_reg(env));
85 
86     return rebuild_hflags_common(env, fp_el, mmu_idx, flags);
87 }
88 
89 static CPUARMTBFlags rebuild_hflags_m32(CPUARMState *env, int fp_el,
90                                         ARMMMUIdx mmu_idx)
91 {
92     CPUARMTBFlags flags = {};
93     uint32_t ccr = env->v7m.ccr[env->v7m.secure];
94 
95     /* Without HaveMainExt, CCR.UNALIGN_TRP is RES1. */
96     if (ccr & R_V7M_CCR_UNALIGN_TRP_MASK) {
97         DP_TBFLAG_ANY(flags, ALIGN_MEM, 1);
98     }
99 
100     if (arm_v7m_is_handler_mode(env)) {
101         DP_TBFLAG_M32(flags, HANDLER, 1);
102     }
103 
104     /*
105      * v8M always applies stack limit checks unless CCR.STKOFHFNMIGN
106      * is suppressing them because the requested execution priority
107      * is less than 0.
108      */
109     if (arm_feature(env, ARM_FEATURE_V8) &&
110         !((mmu_idx & ARM_MMU_IDX_M_NEGPRI) &&
111           (ccr & R_V7M_CCR_STKOFHFNMIGN_MASK))) {
112         DP_TBFLAG_M32(flags, STACKCHECK, 1);
113     }
114 
115     if (arm_feature(env, ARM_FEATURE_M_SECURITY) && env->v7m.secure) {
116         DP_TBFLAG_M32(flags, SECURE, 1);
117     }
118 
119     return rebuild_hflags_common_32(env, fp_el, mmu_idx, flags);
120 }
121 
122 /* This corresponds to the ARM pseudocode function IsFullA64Enabled(). */
123 static bool sme_fa64(CPUARMState *env, int el)
124 {
125     if (!cpu_isar_feature(aa64_sme_fa64, env_archcpu(env))) {
126         return false;
127     }
128 
129     if (el <= 1 && !el_is_in_host(env, el)) {
130         if (!FIELD_EX64(env->vfp.smcr_el[1], SMCR, FA64)) {
131             return false;
132         }
133     }
134     if (el <= 2 && arm_is_el2_enabled(env)) {
135         if (!FIELD_EX64(env->vfp.smcr_el[2], SMCR, FA64)) {
136             return false;
137         }
138     }
139     if (arm_feature(env, ARM_FEATURE_EL3)) {
140         if (!FIELD_EX64(env->vfp.smcr_el[3], SMCR, FA64)) {
141             return false;
142         }
143     }
144 
145     return true;
146 }
147 
148 static CPUARMTBFlags rebuild_hflags_a32(CPUARMState *env, int fp_el,
149                                         ARMMMUIdx mmu_idx)
150 {
151     CPUARMTBFlags flags = {};
152     int el = arm_current_el(env);
153     uint64_t sctlr = arm_sctlr(env, el);
154 
155     if (aprofile_require_alignment(env, el, sctlr)) {
156         DP_TBFLAG_ANY(flags, ALIGN_MEM, 1);
157     }
158 
159     if (arm_el_is_aa64(env, 1)) {
160         DP_TBFLAG_A32(flags, VFPEN, 1);
161     }
162 
163     if (el < 2 && env->cp15.hstr_el2 && arm_is_el2_enabled(env) &&
164         (arm_hcr_el2_eff(env) & (HCR_E2H | HCR_TGE)) != (HCR_E2H | HCR_TGE)) {
165         DP_TBFLAG_A32(flags, HSTR_ACTIVE, 1);
166     }
167 
168     if (arm_fgt_active(env, el)) {
169         DP_TBFLAG_ANY(flags, FGT_ACTIVE, 1);
170         if (fgt_svc(env, el)) {
171             DP_TBFLAG_ANY(flags, FGT_SVC, 1);
172         }
173     }
174 
175     if (env->uncached_cpsr & CPSR_IL) {
176         DP_TBFLAG_ANY(flags, PSTATE__IL, 1);
177     }
178 
179     /*
180      * The SME exception we are testing for is raised via
181      * AArch64.CheckFPAdvSIMDEnabled(), as called from
182      * AArch32.CheckAdvSIMDOrFPEnabled().
183      */
184     if (el == 0
185         && FIELD_EX64(env->svcr, SVCR, SM)
186         && (!arm_is_el2_enabled(env)
187             || (arm_el_is_aa64(env, 2) && !(env->cp15.hcr_el2 & HCR_TGE)))
188         && arm_el_is_aa64(env, 1)
189         && !sme_fa64(env, el)) {
190         DP_TBFLAG_A32(flags, SME_TRAP_NONSTREAMING, 1);
191     }
192 
193     return rebuild_hflags_common_32(env, fp_el, mmu_idx, flags);
194 }
195 
196 static CPUARMTBFlags rebuild_hflags_a64(CPUARMState *env, int el, int fp_el,
197                                         ARMMMUIdx mmu_idx)
198 {
199     CPUARMTBFlags flags = {};
200     ARMMMUIdx stage1 = stage_1_mmu_idx(mmu_idx);
201     uint64_t tcr = regime_tcr(env, mmu_idx);
202     uint64_t hcr = arm_hcr_el2_eff(env);
203     uint64_t sctlr;
204     int tbii, tbid;
205 
206     DP_TBFLAG_ANY(flags, AARCH64_STATE, 1);
207 
208     /* Get control bits for tagged addresses.  */
209     tbid = aa64_va_parameter_tbi(tcr, mmu_idx);
210     tbii = tbid & ~aa64_va_parameter_tbid(tcr, mmu_idx);
211 
212     DP_TBFLAG_A64(flags, TBII, tbii);
213     DP_TBFLAG_A64(flags, TBID, tbid);
214 
215     if (cpu_isar_feature(aa64_sve, env_archcpu(env))) {
216         int sve_el = sve_exception_el(env, el);
217 
218         /*
219          * If either FP or SVE are disabled, translator does not need len.
220          * If SVE EL > FP EL, FP exception has precedence, and translator
221          * does not need SVE EL.  Save potential re-translations by forcing
222          * the unneeded data to zero.
223          */
224         if (fp_el != 0) {
225             if (sve_el > fp_el) {
226                 sve_el = 0;
227             }
228         } else if (sve_el == 0) {
229             DP_TBFLAG_A64(flags, VL, sve_vqm1_for_el(env, el));
230         }
231         DP_TBFLAG_A64(flags, SVEEXC_EL, sve_el);
232     }
233     if (cpu_isar_feature(aa64_sme, env_archcpu(env))) {
234         int sme_el = sme_exception_el(env, el);
235         bool sm = FIELD_EX64(env->svcr, SVCR, SM);
236 
237         DP_TBFLAG_A64(flags, SMEEXC_EL, sme_el);
238         if (sme_el == 0) {
239             /* Similarly, do not compute SVL if SME is disabled. */
240             int svl = sve_vqm1_for_el_sm(env, el, true);
241             DP_TBFLAG_A64(flags, SVL, svl);
242             if (sm) {
243                 /* If SVE is disabled, we will not have set VL above. */
244                 DP_TBFLAG_A64(flags, VL, svl);
245             }
246         }
247         if (sm) {
248             DP_TBFLAG_A64(flags, PSTATE_SM, 1);
249             DP_TBFLAG_A64(flags, SME_TRAP_NONSTREAMING, !sme_fa64(env, el));
250         }
251         DP_TBFLAG_A64(flags, PSTATE_ZA, FIELD_EX64(env->svcr, SVCR, ZA));
252     }
253 
254     sctlr = regime_sctlr(env, stage1);
255 
256     if (aprofile_require_alignment(env, el, sctlr)) {
257         DP_TBFLAG_ANY(flags, ALIGN_MEM, 1);
258     }
259 
260     if (arm_cpu_data_is_big_endian_a64(el, sctlr)) {
261         DP_TBFLAG_ANY(flags, BE_DATA, 1);
262     }
263 
264     if (cpu_isar_feature(aa64_pauth, env_archcpu(env))) {
265         /*
266          * In order to save space in flags, we record only whether
267          * pauth is "inactive", meaning all insns are implemented as
268          * a nop, or "active" when some action must be performed.
269          * The decision of which action to take is left to a helper.
270          */
271         if (sctlr & (SCTLR_EnIA | SCTLR_EnIB | SCTLR_EnDA | SCTLR_EnDB)) {
272             DP_TBFLAG_A64(flags, PAUTH_ACTIVE, 1);
273         }
274     }
275 
276     if (cpu_isar_feature(aa64_bti, env_archcpu(env))) {
277         /* Note that SCTLR_EL[23].BT == SCTLR_BT1.  */
278         if (sctlr & (el == 0 ? SCTLR_BT0 : SCTLR_BT1)) {
279             DP_TBFLAG_A64(flags, BT, 1);
280         }
281     }
282 
283     if (cpu_isar_feature(aa64_lse2, env_archcpu(env))) {
284         if (sctlr & SCTLR_nAA) {
285             DP_TBFLAG_A64(flags, NAA, 1);
286         }
287     }
288 
289     /* Compute the condition for using AccType_UNPRIV for LDTR et al. */
290     if (!(env->pstate & PSTATE_UAO)) {
291         switch (mmu_idx) {
292         case ARMMMUIdx_E10_1:
293         case ARMMMUIdx_E10_1_PAN:
294             /* FEAT_NV: NV,NV1 == 1,1 means we don't do UNPRIV accesses */
295             if ((hcr & (HCR_NV | HCR_NV1)) != (HCR_NV | HCR_NV1)) {
296                 DP_TBFLAG_A64(flags, UNPRIV, 1);
297             }
298             break;
299         case ARMMMUIdx_E20_2:
300         case ARMMMUIdx_E20_2_PAN:
301             /*
302              * Note that EL20_2 is gated by HCR_EL2.E2H == 1, but EL20_0 is
303              * gated by HCR_EL2.<E2H,TGE> == '11', and so is LDTR.
304              */
305             if (env->cp15.hcr_el2 & HCR_TGE) {
306                 DP_TBFLAG_A64(flags, UNPRIV, 1);
307             }
308             break;
309         default:
310             break;
311         }
312     }
313 
314     if (env->pstate & PSTATE_IL) {
315         DP_TBFLAG_ANY(flags, PSTATE__IL, 1);
316     }
317 
318     if (arm_fgt_active(env, el)) {
319         DP_TBFLAG_ANY(flags, FGT_ACTIVE, 1);
320         if (FIELD_EX64(env->cp15.fgt_exec[FGTREG_HFGITR], HFGITR_EL2, ERET)) {
321             DP_TBFLAG_A64(flags, TRAP_ERET, 1);
322         }
323         if (fgt_svc(env, el)) {
324             DP_TBFLAG_ANY(flags, FGT_SVC, 1);
325         }
326     }
327 
328     /*
329      * ERET can also be trapped for FEAT_NV. arm_hcr_el2_eff() takes care
330      * of "is EL2 enabled" and the NV bit can only be set if FEAT_NV is present.
331      */
332     if (el == 1 && (hcr & HCR_NV)) {
333         DP_TBFLAG_A64(flags, TRAP_ERET, 1);
334         DP_TBFLAG_A64(flags, NV, 1);
335         if (hcr & HCR_NV1) {
336             DP_TBFLAG_A64(flags, NV1, 1);
337         }
338         if (hcr & HCR_NV2) {
339             DP_TBFLAG_A64(flags, NV2, 1);
340             if (hcr & HCR_E2H) {
341                 DP_TBFLAG_A64(flags, NV2_MEM_E20, 1);
342             }
343             if (env->cp15.sctlr_el[2] & SCTLR_EE) {
344                 DP_TBFLAG_A64(flags, NV2_MEM_BE, 1);
345             }
346         }
347     }
348 
349     if (cpu_isar_feature(aa64_mte, env_archcpu(env))) {
350         /*
351          * Set MTE_ACTIVE if any access may be Checked, and leave clear
352          * if all accesses must be Unchecked:
353          * 1) If no TBI, then there are no tags in the address to check,
354          * 2) If Tag Check Override, then all accesses are Unchecked,
355          * 3) If Tag Check Fail == 0, then Checked access have no effect,
356          * 4) If no Allocation Tag Access, then all accesses are Unchecked.
357          */
358         if (allocation_tag_access_enabled(env, el, sctlr)) {
359             DP_TBFLAG_A64(flags, ATA, 1);
360             if (tbid
361                 && !(env->pstate & PSTATE_TCO)
362                 && (sctlr & (el == 0 ? SCTLR_TCF0 : SCTLR_TCF))) {
363                 DP_TBFLAG_A64(flags, MTE_ACTIVE, 1);
364                 if (!EX_TBFLAG_A64(flags, UNPRIV)) {
365                     /*
366                      * In non-unpriv contexts (eg EL0), unpriv load/stores
367                      * act like normal ones; duplicate the MTE info to
368                      * avoid translate-a64.c having to check UNPRIV to see
369                      * whether it is OK to index into MTE_ACTIVE[].
370                      */
371                     DP_TBFLAG_A64(flags, MTE0_ACTIVE, 1);
372                 }
373             }
374         }
375         /* And again for unprivileged accesses, if required.  */
376         if (EX_TBFLAG_A64(flags, UNPRIV)
377             && tbid
378             && !(env->pstate & PSTATE_TCO)
379             && (sctlr & SCTLR_TCF0)
380             && allocation_tag_access_enabled(env, 0, sctlr)) {
381             DP_TBFLAG_A64(flags, MTE0_ACTIVE, 1);
382         }
383         /*
384          * For unpriv tag-setting accesses we also need ATA0. Again, in
385          * contexts where unpriv and normal insns are the same we
386          * duplicate the ATA bit to save effort for translate-a64.c.
387          */
388         if (EX_TBFLAG_A64(flags, UNPRIV)) {
389             if (allocation_tag_access_enabled(env, 0, sctlr)) {
390                 DP_TBFLAG_A64(flags, ATA0, 1);
391             }
392         } else {
393             DP_TBFLAG_A64(flags, ATA0, EX_TBFLAG_A64(flags, ATA));
394         }
395         /* Cache TCMA as well as TBI. */
396         DP_TBFLAG_A64(flags, TCMA, aa64_va_parameter_tcma(tcr, mmu_idx));
397     }
398 
399     return rebuild_hflags_common(env, fp_el, mmu_idx, flags);
400 }
401 
402 static CPUARMTBFlags rebuild_hflags_internal(CPUARMState *env)
403 {
404     int el = arm_current_el(env);
405     int fp_el = fp_exception_el(env, el);
406     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
407 
408     if (is_a64(env)) {
409         return rebuild_hflags_a64(env, el, fp_el, mmu_idx);
410     } else if (arm_feature(env, ARM_FEATURE_M)) {
411         return rebuild_hflags_m32(env, fp_el, mmu_idx);
412     } else {
413         return rebuild_hflags_a32(env, fp_el, mmu_idx);
414     }
415 }
416 
417 void arm_rebuild_hflags(CPUARMState *env)
418 {
419     env->hflags = rebuild_hflags_internal(env);
420 }
421 
422 /*
423  * If we have triggered a EL state change we can't rely on the
424  * translator having passed it to us, we need to recompute.
425  */
426 void HELPER(rebuild_hflags_m32_newel)(CPUARMState *env)
427 {
428     int el = arm_current_el(env);
429     int fp_el = fp_exception_el(env, el);
430     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
431 
432     env->hflags = rebuild_hflags_m32(env, fp_el, mmu_idx);
433 }
434 
435 void HELPER(rebuild_hflags_m32)(CPUARMState *env, int el)
436 {
437     int fp_el = fp_exception_el(env, el);
438     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
439 
440     env->hflags = rebuild_hflags_m32(env, fp_el, mmu_idx);
441 }
442 
443 /*
444  * If we have triggered a EL state change we can't rely on the
445  * translator having passed it to us, we need to recompute.
446  */
447 void HELPER(rebuild_hflags_a32_newel)(CPUARMState *env)
448 {
449     int el = arm_current_el(env);
450     int fp_el = fp_exception_el(env, el);
451     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
452     env->hflags = rebuild_hflags_a32(env, fp_el, mmu_idx);
453 }
454 
455 void HELPER(rebuild_hflags_a32)(CPUARMState *env, int el)
456 {
457     int fp_el = fp_exception_el(env, el);
458     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
459 
460     env->hflags = rebuild_hflags_a32(env, fp_el, mmu_idx);
461 }
462 
463 void HELPER(rebuild_hflags_a64)(CPUARMState *env, int el)
464 {
465     int fp_el = fp_exception_el(env, el);
466     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
467 
468     env->hflags = rebuild_hflags_a64(env, el, fp_el, mmu_idx);
469 }
470 
471 void assert_hflags_rebuild_correctly(CPUARMState *env)
472 {
473 #ifdef CONFIG_DEBUG_TCG
474     CPUARMTBFlags c = env->hflags;
475     CPUARMTBFlags r = rebuild_hflags_internal(env);
476 
477     if (unlikely(c.flags != r.flags || c.flags2 != r.flags2)) {
478         fprintf(stderr, "TCG hflags mismatch "
479                         "(current:(0x%08x,0x" TARGET_FMT_lx ")"
480                         " rebuilt:(0x%08x,0x" TARGET_FMT_lx ")\n",
481                 c.flags, c.flags2, r.flags, r.flags2);
482         abort();
483     }
484 #endif
485 }
486