target/m68k: use M68K_FEATURE_MOVEFROMSR_PRIV feature for move_from_sr privilege check

Now that M68K_FEATURE_M68000 has been renamed to M68K_FEATURE_M68K it is easier
to see that the privilege exception check is wrong: it is currently only generated
for ColdFire CPUs when in fact it should also be generated for Motorola CPUs from
the 68010 onwards.

Introduce a new M68K_FEATURE_MOVEFROMSR_PRIV feature which is set for all non-
Motorola CPUs, and for all Motorola CPUs from the 68010 onwards and use it to
determine whether a privilege exception should be generated for the MOVE-from-SR
instruction.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220925134804.139706-3-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

target/m68k/cpu.c

@@ -102,6 +102,7 @@ static void m5206_cpu_initfn(Object *obj)
     CPUM68KState *env = &cpu->env;
 
     m68k_set_feature(env, M68K_FEATURE_CF_ISA_A);
+    m68k_set_feature(env, M68K_FEATURE_MOVEFROMSR_PRIV);
 }
 
 /* Base feature set, including isns. for m68k family */
@@ -129,6 +130,7 @@ static void m68010_cpu_initfn(Object *obj)
     m68k_set_feature(env, M68K_FEATURE_RTD);
     m68k_set_feature(env, M68K_FEATURE_BKPT);
     m68k_set_feature(env, M68K_FEATURE_MOVEC);
+    m68k_set_feature(env, M68K_FEATURE_MOVEFROMSR_PRIV);
 }
 
 /*
@@ -241,6 +243,7 @@ static void m5208_cpu_initfn(Object *obj)
     m68k_set_feature(env, M68K_FEATURE_BRAL);
     m68k_set_feature(env, M68K_FEATURE_CF_EMAC);
     m68k_set_feature(env, M68K_FEATURE_USP);
+    m68k_set_feature(env, M68K_FEATURE_MOVEFROMSR_PRIV);
 }
 
 static void cfv4e_cpu_initfn(Object *obj)
@@ -254,6 +257,7 @@ static void cfv4e_cpu_initfn(Object *obj)
     m68k_set_feature(env, M68K_FEATURE_CF_FPU);
     m68k_set_feature(env, M68K_FEATURE_CF_EMAC);
     m68k_set_feature(env, M68K_FEATURE_USP);
+    m68k_set_feature(env, M68K_FEATURE_MOVEFROMSR_PRIV);
 }
 
 static void any_cpu_initfn(Object *obj)
@@ -275,6 +279,7 @@ static void any_cpu_initfn(Object *obj)
     m68k_set_feature(env, M68K_FEATURE_USP);
     m68k_set_feature(env, M68K_FEATURE_EXT_FULL);
     m68k_set_feature(env, M68K_FEATURE_WORD_INDEX);
+    m68k_set_feature(env, M68K_FEATURE_MOVEFROMSR_PRIV);
 }
 
 static void m68k_cpu_realizefn(DeviceState *dev, Error **errp)

target/m68k/cpu.h

@@ -537,6 +537,8 @@ enum m68k_features {
     M68K_FEATURE_UNALIGNED_DATA,
     /* TRAPcc insn. (680[2346]0, and CPU32) */
     M68K_FEATURE_TRAPCC,
+    /* MOVE from SR privileged (from 68010) */
+    M68K_FEATURE_MOVEFROMSR_PRIV,
 };
 
 static inline bool m68k_feature(CPUM68KState *env, int feature)

target/m68k/translate.c

@@ -4624,7 +4624,7 @@ DISAS_INSN(move_from_sr)
 {
     TCGv sr;
 
-    if (IS_USER(s) && !m68k_feature(env, M68K_FEATURE_M68K)) {
+    if (IS_USER(s) && m68k_feature(env, M68K_FEATURE_MOVEFROMSR_PRIV)) {
         gen_exception(s, s->base.pc_next, EXCP_PRIVILEGE);
         return;
     }