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.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20181012144235.19646-9-peter.maydell@linaro.org

target/arm/helper.c

@@ -8336,7 +8336,7 @@ 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;
@@ -8676,7 +8676,7 @@ 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);
     }
 

target/arm/internals.h

@@ -278,6 +278,11 @@ 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

target/arm/kvm64.c

@@ -933,7 +933,7 @@ int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
 
 bool kvm_arm_handle_debug(CPUState *cs, struct kvm_debug_exit_arch *debug_exit)
 {
-    int hsr_ec = debug_exit->hsr >> ARM_EL_EC_SHIFT;
+    int hsr_ec = syn_get_ec(debug_exit->hsr);
     ARMCPU *cpu = ARM_CPU(cs);
     CPUClass *cc = CPU_GET_CLASS(cs);
     CPUARMState *env = &cpu->env;

target/arm/op_helper.c

@@ -42,7 +42,7 @@ 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();
         }
     }