target/arm: Rename sve_zcr_len_for_el to sve_vqm1_for_el

This will be used for both Normal and Streaming SVE, and the value
does not necessarily come from ZCR_ELx.  While we're at it, emphasize
the units in which the value is returned.

Patch produced by
    git grep -l sve_zcr_len_for_el | \
    xargs -n1 sed -i 's/sve_zcr_len_for_el/sve_vqm1_for_el/g'

and then adding a function comment.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220607203306.657998-13-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

5 files changed, 19 insertions, 10 deletions

diff --git a/target/arm/arch_dump.c b/target/arm/arch_dump.c
index 0184845310..b1f040e69f 100644
--- a/target/arm/arch_dump.c
+++ b/target/arm/arch_dump.c
@@ -166,7 +166,7 @@ static off_t sve_fpcr_offset(uint32_t vq)
 
 static uint32_t sve_current_vq(CPUARMState *env)
 {
-    return sve_zcr_len_for_el(env, arm_current_el(env)) + 1;
+    return sve_vqm1_for_el(env, arm_current_el(env)) + 1;
 }
 
 static size_t sve_size_vq(uint32_t vq)
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 0621944167..1b5d535788 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -925,7 +925,7 @@ static void aarch64_cpu_dump_state(CPUState *cs, FILE *f, int flags)
                  vfp_get_fpcr(env), vfp_get_fpsr(env));
 
     if (cpu_isar_feature(aa64_sve, cpu) && sve_exception_el(env, el) == 0) {
-        int j, zcr_len = sve_zcr_len_for_el(env, el);
+        int j, zcr_len = sve_vqm1_for_el(env, el);
 
         for (i = 0; i <= FFR_PRED_NUM; i++) {
             bool eol;
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 73f24a5760..e45b5cb7fe 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -1132,7 +1132,16 @@ 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);
-uint32_t sve_zcr_len_for_el(CPUARMState *env, int el);
+
+/**
+ * sve_vqm1_for_el:
+ * @env: CPUARMState
+ * @el: exception level
+ *
+ * Compute the current SVE vector length for @el, in units of
+ * Quadwords Minus 1 -- the same scale used for ZCR_ELx.LEN.
+ */
+uint32_t sve_vqm1_for_el(CPUARMState *env, int el);
 
 static inline bool is_a64(CPUARMState *env)
 {
diff --git a/target/arm/gdbstub64.c b/target/arm/gdbstub64.c
index 596878666d..07a6746944 100644
--- a/target/arm/gdbstub64.c
+++ b/target/arm/gdbstub64.c
@@ -152,7 +152,7 @@ int arm_gdb_get_svereg(CPUARMState *env, GByteArray *buf, int reg)
          * We report in Vector Granules (VG) which is 64bit in a Z reg
          * while the ZCR works in Vector Quads (VQ) which is 128bit chunks.
          */
-        int vq = sve_zcr_len_for_el(env, arm_current_el(env)) + 1;
+        int vq = sve_vqm1_for_el(env, arm_current_el(env)) + 1;
         return gdb_get_reg64(buf, vq * 2);
     }
     default:
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 90aac6bc12..400f7cd1db 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -6215,7 +6215,7 @@ int sve_exception_el(CPUARMState *env, int el)
 /*
  * Given that SVE is enabled, return the vector length for EL.
  */
-uint32_t sve_zcr_len_for_el(CPUARMState *env, int el)
+uint32_t sve_vqm1_for_el(CPUARMState *env, int el)
 {
     ARMCPU *cpu = env_archcpu(env);
     uint32_t len = cpu->sve_max_vq - 1;
@@ -6238,7 +6238,7 @@ static void zcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
                       uint64_t value)
 {
     int cur_el = arm_current_el(env);
-    int old_len = sve_zcr_len_for_el(env, cur_el);
+    int old_len = sve_vqm1_for_el(env, cur_el);
     int new_len;
 
     /* Bits other than [3:0] are RAZ/WI.  */
@@ -6249,7 +6249,7 @@ static void zcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
      * Because we arrived here, we know both FP and SVE are enabled;
      * otherwise we would have trapped access to the ZCR_ELn register.
      */
-    new_len = sve_zcr_len_for_el(env, cur_el);
+    new_len = sve_vqm1_for_el(env, cur_el);
     if (new_len < old_len) {
         aarch64_sve_narrow_vq(env, new_len + 1);
     }
@@ -11168,7 +11168,7 @@ static CPUARMTBFlags rebuild_hflags_a64(CPUARMState *env, int el, int fp_el,
                 sve_el = 0;
             }
         } else if (sve_el == 0) {
-            DP_TBFLAG_A64(flags, VL, sve_zcr_len_for_el(env, el));
+            DP_TBFLAG_A64(flags, VL, sve_vqm1_for_el(env, el));
         }
         DP_TBFLAG_A64(flags, SVEEXC_EL, sve_el);
     }
@@ -11534,10 +11534,10 @@ void aarch64_sve_change_el(CPUARMState *env, int old_el,
      */
     old_a64 = old_el ? arm_el_is_aa64(env, old_el) : el0_a64;
     old_len = (old_a64 && !sve_exception_el(env, old_el)
-               ? sve_zcr_len_for_el(env, old_el) : 0);
+               ? sve_vqm1_for_el(env, old_el) : 0);
     new_a64 = new_el ? arm_el_is_aa64(env, new_el) : el0_a64;
     new_len = (new_a64 && !sve_exception_el(env, new_el)
-               ? sve_zcr_len_for_el(env, new_el) : 0);
+               ? sve_vqm1_for_el(env, new_el) : 0);
 
     /* When changing vector length, clear inaccessible state.  */
     if (new_len < old_len) {