From 99516b43a3fe265de9598ceac0efd293c587f9c6 Mon Sep 17 00:00:00 2001
From: Peter Maydell <peter.maydell@linaro.org>
Date: Sat, 10 Nov 2018 09:27:38 -0500
Subject: [PATCH] target/arm: New utility function to extract EC from syndrome

Create and use a utility function to extract the EC field
from a syndrome, rather than open-coding the shift.

Backports commit 64b91e3f890a8c221b65c6820a5ee39107ee40f5 from qemu
---
 qemu/target/arm/helper.c    | 4 ++--
 qemu/target/arm/internals.h | 5 +++++
 qemu/target/arm/op_helper.c | 2 +-
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/qemu/target/arm/helper.c b/qemu/target/arm/helper.c
index aa39e177..570873bc 100644
--- a/qemu/target/arm/helper.c
+++ b/qemu/target/arm/helper.c
@@ -7531,7 +7531,7 @@ static void arm_cpu_do_interrupt_aarch32_(CPUState *cs)
     uint32_t moe;
 
     /* If this is a debug exception we must update the DBGDSCR.MOE bits */
-    switch (env->exception.syndrome >> ARM_EL_EC_SHIFT) {
+    switch (syn_get_ec(env->exception.syndrome)) {
     case EC_BREAKPOINT:
     case EC_BREAKPOINT_SAME_EL:
         moe = 1;
@@ -7877,7 +7877,7 @@ void arm_cpu_do_interrupt(CPUState *cs)
     if (qemu_loglevel_mask(CPU_LOG_INT)
         && !excp_is_internal(cs->exception_index)) {
         qemu_log_mask(CPU_LOG_INT, "...with ESR 0x%x/0x%" PRIx32 "\n",
-                      env->exception.syndrome >> ARM_EL_EC_SHIFT,
+                      syn_get_ec(env->exception.syndrome),
                       env->exception.syndrome);
     }
 
diff --git a/qemu/target/arm/internals.h b/qemu/target/arm/internals.h
index e22ae6ad..31e7fb3d 100644
--- a/qemu/target/arm/internals.h
+++ b/qemu/target/arm/internals.h
@@ -280,6 +280,11 @@ enum arm_exception_class {
 #define ARM_EL_IL (1 << ARM_EL_IL_SHIFT)
 #define ARM_EL_ISV (1 << ARM_EL_ISV_SHIFT)
 
+static inline uint32_t syn_get_ec(uint32_t syn)
+{
+    return syn >> ARM_EL_EC_SHIFT;
+}
+
 /* Utility functions for constructing various kinds of syndrome value.
  * Note that in general we follow the AArch64 syndrome values; in a
  * few cases the value in HSR for exceptions taken to AArch32 Hyp
diff --git a/qemu/target/arm/op_helper.c b/qemu/target/arm/op_helper.c
index 6b644ed6..e5a25940 100644
--- a/qemu/target/arm/op_helper.c
+++ b/qemu/target/arm/op_helper.c
@@ -41,7 +41,7 @@ void raise_exception(CPUARMState *env, uint32_t excp,
          * (see DDI0478C.a D1.10.4)
          */
         target_el = 2;
-        if (syndrome >> ARM_EL_EC_SHIFT == EC_ADVSIMDFPACCESSTRAP) {
+        if (syn_get_ec(syndrome) == EC_ADVSIMDFPACCESSTRAP) {
             syndrome = syn_uncategorized();
         }
     }