target/arm: Add SMEEXC_EL to TB flags

This is CheckSMEAccess, which is the basis for a set of
related tests for various SME cpregs and instructions.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220620175235.60881-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

4 files changed, 56 insertions, 0 deletions

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 05d1e2e8dd..e99de18097 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -1134,6 +1134,7 @@ void aarch64_sync_64_to_32(CPUARMState *env);
 
 int fp_exception_el(CPUARMState *env, int cur_el);
 int sve_exception_el(CPUARMState *env, int cur_el);
+int sme_exception_el(CPUARMState *env, int cur_el);
 
 /**
  * sve_vqm1_for_el:
@@ -3148,6 +3149,7 @@ FIELD(TBFLAG_A64, ATA, 15, 1)
 FIELD(TBFLAG_A64, TCMA, 16, 2)
 FIELD(TBFLAG_A64, MTE_ACTIVE, 18, 1)
 FIELD(TBFLAG_A64, MTE0_ACTIVE, 19, 1)
+FIELD(TBFLAG_A64, SMEEXC_EL, 20, 2)
 
 /*
  * Helpers for using the above.
diff --git a/target/arm/helper.c b/target/arm/helper.c
index d21ba7ab83..2c080c6cac 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -6219,6 +6219,55 @@ int sve_exception_el(CPUARMState *env, int el)
 }
 
 /*
+ * Return the exception level to which exceptions should be taken for SME.
+ * C.f. the ARM pseudocode function CheckSMEAccess.
+ */
+int sme_exception_el(CPUARMState *env, int el)
+{
+#ifndef CONFIG_USER_ONLY
+    if (el <= 1 && !el_is_in_host(env, el)) {
+        switch (FIELD_EX64(env->cp15.cpacr_el1, CPACR_EL1, SMEN)) {
+        case 1:
+            if (el != 0) {
+                break;
+            }
+            /* fall through */
+        case 0:
+        case 2:
+            return 1;
+        }
+    }
+
+    if (el <= 2 && arm_is_el2_enabled(env)) {
+        /* CPTR_EL2 changes format with HCR_EL2.E2H (regardless of TGE). */
+        if (env->cp15.hcr_el2 & HCR_E2H) {
+            switch (FIELD_EX64(env->cp15.cptr_el[2], CPTR_EL2, SMEN)) {
+            case 1:
+                if (el != 0 || !(env->cp15.hcr_el2 & HCR_TGE)) {
+                    break;
+                }
+                /* fall through */
+            case 0:
+            case 2:
+                return 2;
+            }
+        } else {
+            if (FIELD_EX64(env->cp15.cptr_el[2], CPTR_EL2, TSM)) {
+                return 2;
+            }
+        }
+    }
+
+    /* CPTR_EL3.  Since ESM is negative we must check for EL3.  */
+    if (arm_feature(env, ARM_FEATURE_EL3)
+        && !FIELD_EX64(env->cp15.cptr_el[3], CPTR_EL3, ESM)) {
+        return 3;
+    }
+#endif
+    return 0;
+}
+
+/*
  * Given that SVE is enabled, return the vector length for EL.
  */
 uint32_t sve_vqm1_for_el(CPUARMState *env, int el)
@@ -11197,6 +11246,9 @@ static CPUARMTBFlags rebuild_hflags_a64(CPUARMState *env, int el, int fp_el,
         }
         DP_TBFLAG_A64(flags, SVEEXC_EL, sve_el);
     }
+    if (cpu_isar_feature(aa64_sme, env_archcpu(env))) {
+        DP_TBFLAG_A64(flags, SMEEXC_EL, sme_exception_el(env, el));
+    }
 
     sctlr = regime_sctlr(env, stage1);
 
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 4c64546090..9a285dd177 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -14603,6 +14603,7 @@ static void aarch64_tr_init_disas_context(DisasContextBase *dcbase,
     dc->align_mem = EX_TBFLAG_ANY(tb_flags, ALIGN_MEM);
     dc->pstate_il = EX_TBFLAG_ANY(tb_flags, PSTATE__IL);
     dc->sve_excp_el = EX_TBFLAG_A64(tb_flags, SVEEXC_EL);
+    dc->sme_excp_el = EX_TBFLAG_A64(tb_flags, SMEEXC_EL);
     dc->vl = (EX_TBFLAG_A64(tb_flags, VL) + 1) * 16;
     dc->pauth_active = EX_TBFLAG_A64(tb_flags, PAUTH_ACTIVE);
     dc->bt = EX_TBFLAG_A64(tb_flags, BT);
diff --git a/target/arm/translate.h b/target/arm/translate.h
index 88dc18a034..c88c953325 100644
--- a/target/arm/translate.h
+++ b/target/arm/translate.h
@@ -42,6 +42,7 @@ typedef struct DisasContext {
     bool ns;        /* Use non-secure CPREG bank on access */
     int fp_excp_el; /* FP exception EL or 0 if enabled */
     int sve_excp_el; /* SVE exception EL or 0 if enabled */
+    int sme_excp_el; /* SME exception EL or 0 if enabled */
     int vl;          /* current vector length in bytes */
     bool vfp_enabled; /* FP enabled via FPSCR.EN */
     int vec_len;