xref: /openbmc/qemu/target/arm/tcg/hflags.c (revision 542b10bd)
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 static CPUARMTBFlags rebuild_hflags_common(CPUARMState *env, int fp_el,
30                                            ARMMMUIdx mmu_idx,
31                                            CPUARMTBFlags flags)
32 {
33     DP_TBFLAG_ANY(flags, FPEXC_EL, fp_el);
34     DP_TBFLAG_ANY(flags, MMUIDX, arm_to_core_mmu_idx(mmu_idx));
35 
36     if (arm_singlestep_active(env)) {
37         DP_TBFLAG_ANY(flags, SS_ACTIVE, 1);
38     }
39 
40     return flags;
41 }
42 
43 static CPUARMTBFlags rebuild_hflags_common_32(CPUARMState *env, int fp_el,
44                                               ARMMMUIdx mmu_idx,
45                                               CPUARMTBFlags flags)
46 {
47     bool sctlr_b = arm_sctlr_b(env);
48 
49     if (sctlr_b) {
50         DP_TBFLAG_A32(flags, SCTLR__B, 1);
51     }
52     if (arm_cpu_data_is_big_endian_a32(env, sctlr_b)) {
53         DP_TBFLAG_ANY(flags, BE_DATA, 1);
54     }
55     DP_TBFLAG_A32(flags, NS, !access_secure_reg(env));
56 
57     return rebuild_hflags_common(env, fp_el, mmu_idx, flags);
58 }
59 
60 static CPUARMTBFlags rebuild_hflags_m32(CPUARMState *env, int fp_el,
61                                         ARMMMUIdx mmu_idx)
62 {
63     CPUARMTBFlags flags = {};
64     uint32_t ccr = env->v7m.ccr[env->v7m.secure];
65 
66     /* Without HaveMainExt, CCR.UNALIGN_TRP is RES1. */
67     if (ccr & R_V7M_CCR_UNALIGN_TRP_MASK) {
68         DP_TBFLAG_ANY(flags, ALIGN_MEM, 1);
69     }
70 
71     if (arm_v7m_is_handler_mode(env)) {
72         DP_TBFLAG_M32(flags, HANDLER, 1);
73     }
74 
75     /*
76      * v8M always applies stack limit checks unless CCR.STKOFHFNMIGN
77      * is suppressing them because the requested execution priority
78      * is less than 0.
79      */
80     if (arm_feature(env, ARM_FEATURE_V8) &&
81         !((mmu_idx & ARM_MMU_IDX_M_NEGPRI) &&
82           (ccr & R_V7M_CCR_STKOFHFNMIGN_MASK))) {
83         DP_TBFLAG_M32(flags, STACKCHECK, 1);
84     }
85 
86     if (arm_feature(env, ARM_FEATURE_M_SECURITY) && env->v7m.secure) {
87         DP_TBFLAG_M32(flags, SECURE, 1);
88     }
89 
90     return rebuild_hflags_common_32(env, fp_el, mmu_idx, flags);
91 }
92 
93 /* This corresponds to the ARM pseudocode function IsFullA64Enabled(). */
94 static bool sme_fa64(CPUARMState *env, int el)
95 {
96     if (!cpu_isar_feature(aa64_sme_fa64, env_archcpu(env))) {
97         return false;
98     }
99 
100     if (el <= 1 && !el_is_in_host(env, el)) {
101         if (!FIELD_EX64(env->vfp.smcr_el[1], SMCR, FA64)) {
102             return false;
103         }
104     }
105     if (el <= 2 && arm_is_el2_enabled(env)) {
106         if (!FIELD_EX64(env->vfp.smcr_el[2], SMCR, FA64)) {
107             return false;
108         }
109     }
110     if (arm_feature(env, ARM_FEATURE_EL3)) {
111         if (!FIELD_EX64(env->vfp.smcr_el[3], SMCR, FA64)) {
112             return false;
113         }
114     }
115 
116     return true;
117 }
118 
119 static CPUARMTBFlags rebuild_hflags_a32(CPUARMState *env, int fp_el,
120                                         ARMMMUIdx mmu_idx)
121 {
122     CPUARMTBFlags flags = {};
123     int el = arm_current_el(env);
124 
125     if (arm_sctlr(env, el) & SCTLR_A) {
126         DP_TBFLAG_ANY(flags, ALIGN_MEM, 1);
127     }
128 
129     if (arm_el_is_aa64(env, 1)) {
130         DP_TBFLAG_A32(flags, VFPEN, 1);
131     }
132 
133     if (el < 2 && env->cp15.hstr_el2 && arm_is_el2_enabled(env) &&
134         (arm_hcr_el2_eff(env) & (HCR_E2H | HCR_TGE)) != (HCR_E2H | HCR_TGE)) {
135         DP_TBFLAG_A32(flags, HSTR_ACTIVE, 1);
136     }
137 
138     if (arm_fgt_active(env, el)) {
139         DP_TBFLAG_ANY(flags, FGT_ACTIVE, 1);
140         if (fgt_svc(env, el)) {
141             DP_TBFLAG_ANY(flags, FGT_SVC, 1);
142         }
143     }
144 
145     if (env->uncached_cpsr & CPSR_IL) {
146         DP_TBFLAG_ANY(flags, PSTATE__IL, 1);
147     }
148 
149     /*
150      * The SME exception we are testing for is raised via
151      * AArch64.CheckFPAdvSIMDEnabled(), as called from
152      * AArch32.CheckAdvSIMDOrFPEnabled().
153      */
154     if (el == 0
155         && FIELD_EX64(env->svcr, SVCR, SM)
156         && (!arm_is_el2_enabled(env)
157             || (arm_el_is_aa64(env, 2) && !(env->cp15.hcr_el2 & HCR_TGE)))
158         && arm_el_is_aa64(env, 1)
159         && !sme_fa64(env, el)) {
160         DP_TBFLAG_A32(flags, SME_TRAP_NONSTREAMING, 1);
161     }
162 
163     return rebuild_hflags_common_32(env, fp_el, mmu_idx, flags);
164 }
165 
166 static CPUARMTBFlags rebuild_hflags_a64(CPUARMState *env, int el, int fp_el,
167                                         ARMMMUIdx mmu_idx)
168 {
169     CPUARMTBFlags flags = {};
170     ARMMMUIdx stage1 = stage_1_mmu_idx(mmu_idx);
171     uint64_t tcr = regime_tcr(env, mmu_idx);
172     uint64_t hcr = arm_hcr_el2_eff(env);
173     uint64_t sctlr;
174     int tbii, tbid;
175 
176     DP_TBFLAG_ANY(flags, AARCH64_STATE, 1);
177 
178     /* Get control bits for tagged addresses.  */
179     tbid = aa64_va_parameter_tbi(tcr, mmu_idx);
180     tbii = tbid & ~aa64_va_parameter_tbid(tcr, mmu_idx);
181 
182     DP_TBFLAG_A64(flags, TBII, tbii);
183     DP_TBFLAG_A64(flags, TBID, tbid);
184 
185     if (cpu_isar_feature(aa64_sve, env_archcpu(env))) {
186         int sve_el = sve_exception_el(env, el);
187 
188         /*
189          * If either FP or SVE are disabled, translator does not need len.
190          * If SVE EL > FP EL, FP exception has precedence, and translator
191          * does not need SVE EL.  Save potential re-translations by forcing
192          * the unneeded data to zero.
193          */
194         if (fp_el != 0) {
195             if (sve_el > fp_el) {
196                 sve_el = 0;
197             }
198         } else if (sve_el == 0) {
199             DP_TBFLAG_A64(flags, VL, sve_vqm1_for_el(env, el));
200         }
201         DP_TBFLAG_A64(flags, SVEEXC_EL, sve_el);
202     }
203     if (cpu_isar_feature(aa64_sme, env_archcpu(env))) {
204         int sme_el = sme_exception_el(env, el);
205         bool sm = FIELD_EX64(env->svcr, SVCR, SM);
206 
207         DP_TBFLAG_A64(flags, SMEEXC_EL, sme_el);
208         if (sme_el == 0) {
209             /* Similarly, do not compute SVL if SME is disabled. */
210             int svl = sve_vqm1_for_el_sm(env, el, true);
211             DP_TBFLAG_A64(flags, SVL, svl);
212             if (sm) {
213                 /* If SVE is disabled, we will not have set VL above. */
214                 DP_TBFLAG_A64(flags, VL, svl);
215             }
216         }
217         if (sm) {
218             DP_TBFLAG_A64(flags, PSTATE_SM, 1);
219             DP_TBFLAG_A64(flags, SME_TRAP_NONSTREAMING, !sme_fa64(env, el));
220         }
221         DP_TBFLAG_A64(flags, PSTATE_ZA, FIELD_EX64(env->svcr, SVCR, ZA));
222     }
223 
224     sctlr = regime_sctlr(env, stage1);
225 
226     if (sctlr & SCTLR_A) {
227         DP_TBFLAG_ANY(flags, ALIGN_MEM, 1);
228     }
229 
230     if (arm_cpu_data_is_big_endian_a64(el, sctlr)) {
231         DP_TBFLAG_ANY(flags, BE_DATA, 1);
232     }
233 
234     if (cpu_isar_feature(aa64_pauth, env_archcpu(env))) {
235         /*
236          * In order to save space in flags, we record only whether
237          * pauth is "inactive", meaning all insns are implemented as
238          * a nop, or "active" when some action must be performed.
239          * The decision of which action to take is left to a helper.
240          */
241         if (sctlr & (SCTLR_EnIA | SCTLR_EnIB | SCTLR_EnDA | SCTLR_EnDB)) {
242             DP_TBFLAG_A64(flags, PAUTH_ACTIVE, 1);
243         }
244     }
245 
246     if (cpu_isar_feature(aa64_bti, env_archcpu(env))) {
247         /* Note that SCTLR_EL[23].BT == SCTLR_BT1.  */
248         if (sctlr & (el == 0 ? SCTLR_BT0 : SCTLR_BT1)) {
249             DP_TBFLAG_A64(flags, BT, 1);
250         }
251     }
252 
253     if (cpu_isar_feature(aa64_lse2, env_archcpu(env))) {
254         if (sctlr & SCTLR_nAA) {
255             DP_TBFLAG_A64(flags, NAA, 1);
256         }
257     }
258 
259     /* Compute the condition for using AccType_UNPRIV for LDTR et al. */
260     if (!(env->pstate & PSTATE_UAO)) {
261         switch (mmu_idx) {
262         case ARMMMUIdx_E10_1:
263         case ARMMMUIdx_E10_1_PAN:
264             /* FEAT_NV: NV,NV1 == 1,1 means we don't do UNPRIV accesses */
265             if ((hcr & (HCR_NV | HCR_NV1)) != (HCR_NV | HCR_NV1)) {
266                 DP_TBFLAG_A64(flags, UNPRIV, 1);
267             }
268             break;
269         case ARMMMUIdx_E20_2:
270         case ARMMMUIdx_E20_2_PAN:
271             /*
272              * Note that EL20_2 is gated by HCR_EL2.E2H == 1, but EL20_0 is
273              * gated by HCR_EL2.<E2H,TGE> == '11', and so is LDTR.
274              */
275             if (env->cp15.hcr_el2 & HCR_TGE) {
276                 DP_TBFLAG_A64(flags, UNPRIV, 1);
277             }
278             break;
279         default:
280             break;
281         }
282     }
283 
284     if (env->pstate & PSTATE_IL) {
285         DP_TBFLAG_ANY(flags, PSTATE__IL, 1);
286     }
287 
288     if (arm_fgt_active(env, el)) {
289         DP_TBFLAG_ANY(flags, FGT_ACTIVE, 1);
290         if (FIELD_EX64(env->cp15.fgt_exec[FGTREG_HFGITR], HFGITR_EL2, ERET)) {
291             DP_TBFLAG_A64(flags, TRAP_ERET, 1);
292         }
293         if (fgt_svc(env, el)) {
294             DP_TBFLAG_ANY(flags, FGT_SVC, 1);
295         }
296     }
297 
298     /*
299      * ERET can also be trapped for FEAT_NV. arm_hcr_el2_eff() takes care
300      * of "is EL2 enabled" and the NV bit can only be set if FEAT_NV is present.
301      */
302     if (el == 1 && (hcr & HCR_NV)) {
303         DP_TBFLAG_A64(flags, TRAP_ERET, 1);
304         DP_TBFLAG_A64(flags, NV, 1);
305         if (hcr & HCR_NV1) {
306             DP_TBFLAG_A64(flags, NV1, 1);
307         }
308         if (hcr & HCR_NV2) {
309             DP_TBFLAG_A64(flags, NV2, 1);
310             if (hcr & HCR_E2H) {
311                 DP_TBFLAG_A64(flags, NV2_MEM_E20, 1);
312             }
313             if (env->cp15.sctlr_el[2] & SCTLR_EE) {
314                 DP_TBFLAG_A64(flags, NV2_MEM_BE, 1);
315             }
316         }
317     }
318 
319     if (cpu_isar_feature(aa64_mte, env_archcpu(env))) {
320         /*
321          * Set MTE_ACTIVE if any access may be Checked, and leave clear
322          * if all accesses must be Unchecked:
323          * 1) If no TBI, then there are no tags in the address to check,
324          * 2) If Tag Check Override, then all accesses are Unchecked,
325          * 3) If Tag Check Fail == 0, then Checked access have no effect,
326          * 4) If no Allocation Tag Access, then all accesses are Unchecked.
327          */
328         if (allocation_tag_access_enabled(env, el, sctlr)) {
329             DP_TBFLAG_A64(flags, ATA, 1);
330             if (tbid
331                 && !(env->pstate & PSTATE_TCO)
332                 && (sctlr & (el == 0 ? SCTLR_TCF0 : SCTLR_TCF))) {
333                 DP_TBFLAG_A64(flags, MTE_ACTIVE, 1);
334                 if (!EX_TBFLAG_A64(flags, UNPRIV)) {
335                     /*
336                      * In non-unpriv contexts (eg EL0), unpriv load/stores
337                      * act like normal ones; duplicate the MTE info to
338                      * avoid translate-a64.c having to check UNPRIV to see
339                      * whether it is OK to index into MTE_ACTIVE[].
340                      */
341                     DP_TBFLAG_A64(flags, MTE0_ACTIVE, 1);
342                 }
343             }
344         }
345         /* And again for unprivileged accesses, if required.  */
346         if (EX_TBFLAG_A64(flags, UNPRIV)
347             && tbid
348             && !(env->pstate & PSTATE_TCO)
349             && (sctlr & SCTLR_TCF0)
350             && allocation_tag_access_enabled(env, 0, sctlr)) {
351             DP_TBFLAG_A64(flags, MTE0_ACTIVE, 1);
352         }
353         /*
354          * For unpriv tag-setting accesses we also need ATA0. Again, in
355          * contexts where unpriv and normal insns are the same we
356          * duplicate the ATA bit to save effort for translate-a64.c.
357          */
358         if (EX_TBFLAG_A64(flags, UNPRIV)) {
359             if (allocation_tag_access_enabled(env, 0, sctlr)) {
360                 DP_TBFLAG_A64(flags, ATA0, 1);
361             }
362         } else {
363             DP_TBFLAG_A64(flags, ATA0, EX_TBFLAG_A64(flags, ATA));
364         }
365         /* Cache TCMA as well as TBI. */
366         DP_TBFLAG_A64(flags, TCMA, aa64_va_parameter_tcma(tcr, mmu_idx));
367     }
368 
369     return rebuild_hflags_common(env, fp_el, mmu_idx, flags);
370 }
371 
372 static CPUARMTBFlags rebuild_hflags_internal(CPUARMState *env)
373 {
374     int el = arm_current_el(env);
375     int fp_el = fp_exception_el(env, el);
376     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
377 
378     if (is_a64(env)) {
379         return rebuild_hflags_a64(env, el, fp_el, mmu_idx);
380     } else if (arm_feature(env, ARM_FEATURE_M)) {
381         return rebuild_hflags_m32(env, fp_el, mmu_idx);
382     } else {
383         return rebuild_hflags_a32(env, fp_el, mmu_idx);
384     }
385 }
386 
387 void arm_rebuild_hflags(CPUARMState *env)
388 {
389     env->hflags = rebuild_hflags_internal(env);
390 }
391 
392 /*
393  * If we have triggered a EL state change we can't rely on the
394  * translator having passed it to us, we need to recompute.
395  */
396 void HELPER(rebuild_hflags_m32_newel)(CPUARMState *env)
397 {
398     int el = arm_current_el(env);
399     int fp_el = fp_exception_el(env, el);
400     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
401 
402     env->hflags = rebuild_hflags_m32(env, fp_el, mmu_idx);
403 }
404 
405 void HELPER(rebuild_hflags_m32)(CPUARMState *env, int el)
406 {
407     int fp_el = fp_exception_el(env, el);
408     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
409 
410     env->hflags = rebuild_hflags_m32(env, fp_el, mmu_idx);
411 }
412 
413 /*
414  * If we have triggered a EL state change we can't rely on the
415  * translator having passed it to us, we need to recompute.
416  */
417 void HELPER(rebuild_hflags_a32_newel)(CPUARMState *env)
418 {
419     int el = arm_current_el(env);
420     int fp_el = fp_exception_el(env, el);
421     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
422     env->hflags = rebuild_hflags_a32(env, fp_el, mmu_idx);
423 }
424 
425 void HELPER(rebuild_hflags_a32)(CPUARMState *env, int el)
426 {
427     int fp_el = fp_exception_el(env, el);
428     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
429 
430     env->hflags = rebuild_hflags_a32(env, fp_el, mmu_idx);
431 }
432 
433 void HELPER(rebuild_hflags_a64)(CPUARMState *env, int el)
434 {
435     int fp_el = fp_exception_el(env, el);
436     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
437 
438     env->hflags = rebuild_hflags_a64(env, el, fp_el, mmu_idx);
439 }
440 
441 void assert_hflags_rebuild_correctly(CPUARMState *env)
442 {
443 #ifdef CONFIG_DEBUG_TCG
444     CPUARMTBFlags c = env->hflags;
445     CPUARMTBFlags r = rebuild_hflags_internal(env);
446 
447     if (unlikely(c.flags != r.flags || c.flags2 != r.flags2)) {
448         fprintf(stderr, "TCG hflags mismatch "
449                         "(current:(0x%08x,0x" TARGET_FMT_lx ")"
450                         " rebuilt:(0x%08x,0x" TARGET_FMT_lx ")\n",
451                 c.flags, c.flags2, r.flags, r.flags2);
452         abort();
453     }
454 #endif
455 }
456