target/arm: Add GPC syndrome

The function takes the fields as filled in by
the Arm ARM pseudocode for TakeGPCException.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230620124418.805717-18-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/syndrome.h

@@ -50,6 +50,7 @@ enum arm_exception_class {
     EC_SVEACCESSTRAP          = 0x19,
     EC_ERETTRAP               = 0x1a,
     EC_SMETRAP                = 0x1d,
+    EC_GPC                    = 0x1e,
     EC_INSNABORT              = 0x20,
     EC_INSNABORT_SAME_EL      = 0x21,
     EC_PCALIGNMENT            = 0x22,
@@ -247,6 +248,15 @@ static inline uint32_t syn_bxjtrap(int cv, int cond, int rm)
         (cv << 24) | (cond << 20) | rm;
 }
 
+static inline uint32_t syn_gpc(int s2ptw, int ind, int gpcsc,
+                               int cm, int s1ptw, int wnr, int fsc)
+{
+    /* TODO: FEAT_NV2 adds VNCR */
+    return (EC_GPC << ARM_EL_EC_SHIFT) | ARM_EL_IL | (s2ptw << 21)
+            | (ind << 20) | (gpcsc << 14) | (cm << 8) | (s1ptw << 7)
+            | (wnr << 6) | fsc;
+}
+
 static inline uint32_t syn_insn_abort(int same_el, int ea, int s1ptw, int fsc)
 {
     return (EC_INSNABORT << ARM_EL_EC_SHIFT) | (same_el << ARM_EL_EC_SHIFT)