[PULL 22/25] target/arm: Add SVL to TB flags

[Peter Maydell <peter.maydell@linaro.org>]

From: Richard Henderson <richard.henderson@linaro.org>

We need SVL separate from VL for RDSVL et al, as well as
ZA storage loads and stores, which do not require PSTATE.SM.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220620175235.60881-20-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/cpu.h           | 12 ++++++++++++
 target/arm/translate.h     |  1 +
 target/arm/helper.c        |  8 +++++++-
 target/arm/translate-a64.c |  1 +
 4 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 0295e854838..4a4342f2622 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -3182,6 +3182,7 @@ FIELD(TBFLAG_A64, MTE0_ACTIVE, 19, 1)
 FIELD(TBFLAG_A64, SMEEXC_EL, 20, 2)
 FIELD(TBFLAG_A64, PSTATE_SM, 22, 1)
 FIELD(TBFLAG_A64, PSTATE_ZA, 23, 1)
+FIELD(TBFLAG_A64, SVL, 24, 4)
 
 /*
  * Helpers for using the above.
@@ -3227,6 +3228,17 @@ static inline int sve_vq(CPUARMState *env)
     return EX_TBFLAG_A64(env->hflags, VL) + 1;
 }
 
+/**
+ * sme_vq
+ * @env: the cpu context
+ *
+ * Return the SVL cached within env->hflags, in units of quadwords.
+ */
+static inline int sme_vq(CPUARMState *env)
+{
+    return EX_TBFLAG_A64(env->hflags, SVL) + 1;
+}
+
 static inline bool bswap_code(bool sctlr_b)
 {
 #ifdef CONFIG_USER_ONLY
diff --git a/target/arm/translate.h b/target/arm/translate.h
index 93766649f7f..22fd882368b 100644
--- a/target/arm/translate.h
+++ b/target/arm/translate.h
@@ -44,6 +44,7 @@ typedef struct DisasContext {
     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 */
+    int svl;         /* current streaming vector length in bytes */
     bool vfp_enabled; /* FP enabled via FPSCR.EN */
     int vec_len;
     int vec_stride;
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 2e4e739969a..d2886a123a6 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -11352,7 +11352,13 @@ 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));
+        int sme_el = sme_exception_el(env, el);
+
+        DP_TBFLAG_A64(flags, SMEEXC_EL, sme_el);
+        if (sme_el == 0) {
+            /* Similarly, do not compute SVL if SME is disabled. */
+            DP_TBFLAG_A64(flags, SVL, sve_vqm1_for_el_sm(env, el, true));
+        }
         if (FIELD_EX64(env->svcr, SVCR, SM)) {
             DP_TBFLAG_A64(flags, PSTATE_SM, 1);
         }
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index c050ebe0053..c86b97b1d49 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -14647,6 +14647,7 @@ static void aarch64_tr_init_disas_context(DisasContextBase *dcbase,
     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->svl = (EX_TBFLAG_A64(tb_flags, SVL) + 1) * 16;
     dc->pauth_active = EX_TBFLAG_A64(tb_flags, PAUTH_ACTIVE);
     dc->bt = EX_TBFLAG_A64(tb_flags, BT);
     dc->btype = EX_TBFLAG_A64(tb_flags, BTYPE);
-- 
2.25.1