xref: /openbmc/qemu/target/arm/tcg/hflags.c (revision 55339361)
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 sctlr;
173     int tbii, tbid;
174 
175     DP_TBFLAG_ANY(flags, AARCH64_STATE, 1);
176 
177     /* Get control bits for tagged addresses.  */
178     tbid = aa64_va_parameter_tbi(tcr, mmu_idx);
179     tbii = tbid & ~aa64_va_parameter_tbid(tcr, mmu_idx);
180 
181     DP_TBFLAG_A64(flags, TBII, tbii);
182     DP_TBFLAG_A64(flags, TBID, tbid);
183 
184     if (cpu_isar_feature(aa64_sve, env_archcpu(env))) {
185         int sve_el = sve_exception_el(env, el);
186 
187         /*
188          * If either FP or SVE are disabled, translator does not need len.
189          * If SVE EL > FP EL, FP exception has precedence, and translator
190          * does not need SVE EL.  Save potential re-translations by forcing
191          * the unneeded data to zero.
192          */
193         if (fp_el != 0) {
194             if (sve_el > fp_el) {
195                 sve_el = 0;
196             }
197         } else if (sve_el == 0) {
198             DP_TBFLAG_A64(flags, VL, sve_vqm1_for_el(env, el));
199         }
200         DP_TBFLAG_A64(flags, SVEEXC_EL, sve_el);
201     }
202     if (cpu_isar_feature(aa64_sme, env_archcpu(env))) {
203         int sme_el = sme_exception_el(env, el);
204         bool sm = FIELD_EX64(env->svcr, SVCR, SM);
205 
206         DP_TBFLAG_A64(flags, SMEEXC_EL, sme_el);
207         if (sme_el == 0) {
208             /* Similarly, do not compute SVL if SME is disabled. */
209             int svl = sve_vqm1_for_el_sm(env, el, true);
210             DP_TBFLAG_A64(flags, SVL, svl);
211             if (sm) {
212                 /* If SVE is disabled, we will not have set VL above. */
213                 DP_TBFLAG_A64(flags, VL, svl);
214             }
215         }
216         if (sm) {
217             DP_TBFLAG_A64(flags, PSTATE_SM, 1);
218             DP_TBFLAG_A64(flags, SME_TRAP_NONSTREAMING, !sme_fa64(env, el));
219         }
220         DP_TBFLAG_A64(flags, PSTATE_ZA, FIELD_EX64(env->svcr, SVCR, ZA));
221     }
222 
223     sctlr = regime_sctlr(env, stage1);
224 
225     if (sctlr & SCTLR_A) {
226         DP_TBFLAG_ANY(flags, ALIGN_MEM, 1);
227     }
228 
229     if (arm_cpu_data_is_big_endian_a64(el, sctlr)) {
230         DP_TBFLAG_ANY(flags, BE_DATA, 1);
231     }
232 
233     if (cpu_isar_feature(aa64_pauth, env_archcpu(env))) {
234         /*
235          * In order to save space in flags, we record only whether
236          * pauth is "inactive", meaning all insns are implemented as
237          * a nop, or "active" when some action must be performed.
238          * The decision of which action to take is left to a helper.
239          */
240         if (sctlr & (SCTLR_EnIA | SCTLR_EnIB | SCTLR_EnDA | SCTLR_EnDB)) {
241             DP_TBFLAG_A64(flags, PAUTH_ACTIVE, 1);
242         }
243     }
244 
245     if (cpu_isar_feature(aa64_bti, env_archcpu(env))) {
246         /* Note that SCTLR_EL[23].BT == SCTLR_BT1.  */
247         if (sctlr & (el == 0 ? SCTLR_BT0 : SCTLR_BT1)) {
248             DP_TBFLAG_A64(flags, BT, 1);
249         }
250     }
251 
252     if (cpu_isar_feature(aa64_lse2, env_archcpu(env))) {
253         if (sctlr & SCTLR_nAA) {
254             DP_TBFLAG_A64(flags, NAA, 1);
255         }
256     }
257 
258     /* Compute the condition for using AccType_UNPRIV for LDTR et al. */
259     if (!(env->pstate & PSTATE_UAO)) {
260         switch (mmu_idx) {
261         case ARMMMUIdx_E10_1:
262         case ARMMMUIdx_E10_1_PAN:
263             /* TODO: ARMv8.3-NV */
264             DP_TBFLAG_A64(flags, UNPRIV, 1);
265             break;
266         case ARMMMUIdx_E20_2:
267         case ARMMMUIdx_E20_2_PAN:
268             /*
269              * Note that EL20_2 is gated by HCR_EL2.E2H == 1, but EL20_0 is
270              * gated by HCR_EL2.<E2H,TGE> == '11', and so is LDTR.
271              */
272             if (env->cp15.hcr_el2 & HCR_TGE) {
273                 DP_TBFLAG_A64(flags, UNPRIV, 1);
274             }
275             break;
276         default:
277             break;
278         }
279     }
280 
281     if (env->pstate & PSTATE_IL) {
282         DP_TBFLAG_ANY(flags, PSTATE__IL, 1);
283     }
284 
285     if (arm_fgt_active(env, el)) {
286         DP_TBFLAG_ANY(flags, FGT_ACTIVE, 1);
287         if (FIELD_EX64(env->cp15.fgt_exec[FGTREG_HFGITR], HFGITR_EL2, ERET)) {
288             DP_TBFLAG_A64(flags, FGT_ERET, 1);
289         }
290         if (fgt_svc(env, el)) {
291             DP_TBFLAG_ANY(flags, FGT_SVC, 1);
292         }
293     }
294 
295     if (cpu_isar_feature(aa64_mte, env_archcpu(env))) {
296         /*
297          * Set MTE_ACTIVE if any access may be Checked, and leave clear
298          * if all accesses must be Unchecked:
299          * 1) If no TBI, then there are no tags in the address to check,
300          * 2) If Tag Check Override, then all accesses are Unchecked,
301          * 3) If Tag Check Fail == 0, then Checked access have no effect,
302          * 4) If no Allocation Tag Access, then all accesses are Unchecked.
303          */
304         if (allocation_tag_access_enabled(env, el, sctlr)) {
305             DP_TBFLAG_A64(flags, ATA, 1);
306             if (tbid
307                 && !(env->pstate & PSTATE_TCO)
308                 && (sctlr & (el == 0 ? SCTLR_TCF0 : SCTLR_TCF))) {
309                 DP_TBFLAG_A64(flags, MTE_ACTIVE, 1);
310                 if (!EX_TBFLAG_A64(flags, UNPRIV)) {
311                     /*
312                      * In non-unpriv contexts (eg EL0), unpriv load/stores
313                      * act like normal ones; duplicate the MTE info to
314                      * avoid translate-a64.c having to check UNPRIV to see
315                      * whether it is OK to index into MTE_ACTIVE[].
316                      */
317                     DP_TBFLAG_A64(flags, MTE0_ACTIVE, 1);
318                 }
319             }
320         }
321         /* And again for unprivileged accesses, if required.  */
322         if (EX_TBFLAG_A64(flags, UNPRIV)
323             && tbid
324             && !(env->pstate & PSTATE_TCO)
325             && (sctlr & SCTLR_TCF0)
326             && allocation_tag_access_enabled(env, 0, sctlr)) {
327             DP_TBFLAG_A64(flags, MTE0_ACTIVE, 1);
328         }
329         /*
330          * For unpriv tag-setting accesses we also need ATA0. Again, in
331          * contexts where unpriv and normal insns are the same we
332          * duplicate the ATA bit to save effort for translate-a64.c.
333          */
334         if (EX_TBFLAG_A64(flags, UNPRIV)) {
335             if (allocation_tag_access_enabled(env, 0, sctlr)) {
336                 DP_TBFLAG_A64(flags, ATA0, 1);
337             }
338         } else {
339             DP_TBFLAG_A64(flags, ATA0, EX_TBFLAG_A64(flags, ATA));
340         }
341         /* Cache TCMA as well as TBI. */
342         DP_TBFLAG_A64(flags, TCMA, aa64_va_parameter_tcma(tcr, mmu_idx));
343     }
344 
345     return rebuild_hflags_common(env, fp_el, mmu_idx, flags);
346 }
347 
348 static CPUARMTBFlags rebuild_hflags_internal(CPUARMState *env)
349 {
350     int el = arm_current_el(env);
351     int fp_el = fp_exception_el(env, el);
352     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
353 
354     if (is_a64(env)) {
355         return rebuild_hflags_a64(env, el, fp_el, mmu_idx);
356     } else if (arm_feature(env, ARM_FEATURE_M)) {
357         return rebuild_hflags_m32(env, fp_el, mmu_idx);
358     } else {
359         return rebuild_hflags_a32(env, fp_el, mmu_idx);
360     }
361 }
362 
363 void arm_rebuild_hflags(CPUARMState *env)
364 {
365     env->hflags = rebuild_hflags_internal(env);
366 }
367 
368 /*
369  * If we have triggered a EL state change we can't rely on the
370  * translator having passed it to us, we need to recompute.
371  */
372 void HELPER(rebuild_hflags_m32_newel)(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     env->hflags = rebuild_hflags_m32(env, fp_el, mmu_idx);
379 }
380 
381 void HELPER(rebuild_hflags_m32)(CPUARMState *env, int el)
382 {
383     int fp_el = fp_exception_el(env, el);
384     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
385 
386     env->hflags = rebuild_hflags_m32(env, fp_el, mmu_idx);
387 }
388 
389 /*
390  * If we have triggered a EL state change we can't rely on the
391  * translator having passed it to us, we need to recompute.
392  */
393 void HELPER(rebuild_hflags_a32_newel)(CPUARMState *env)
394 {
395     int el = arm_current_el(env);
396     int fp_el = fp_exception_el(env, el);
397     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
398     env->hflags = rebuild_hflags_a32(env, fp_el, mmu_idx);
399 }
400 
401 void HELPER(rebuild_hflags_a32)(CPUARMState *env, int el)
402 {
403     int fp_el = fp_exception_el(env, el);
404     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
405 
406     env->hflags = rebuild_hflags_a32(env, fp_el, mmu_idx);
407 }
408 
409 void HELPER(rebuild_hflags_a64)(CPUARMState *env, int el)
410 {
411     int fp_el = fp_exception_el(env, el);
412     ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, el);
413 
414     env->hflags = rebuild_hflags_a64(env, el, fp_el, mmu_idx);
415 }
416 
417 void assert_hflags_rebuild_correctly(CPUARMState *env)
418 {
419 #ifdef CONFIG_DEBUG_TCG
420     CPUARMTBFlags c = env->hflags;
421     CPUARMTBFlags r = rebuild_hflags_internal(env);
422 
423     if (unlikely(c.flags != r.flags || c.flags2 != r.flags2)) {
424         fprintf(stderr, "TCG hflags mismatch "
425                         "(current:(0x%08x,0x" TARGET_FMT_lx ")"
426                         " rebuilt:(0x%08x,0x" TARGET_FMT_lx ")\n",
427                 c.flags, c.flags2, r.flags, r.flags2);
428         abort();
429     }
430 #endif
431 }
432