Merge remote-tracking branch 'remotes/vivier/tags/m68k-for-2.10-pull-request' into staging

# gpg: Signature made Wed 07 Jun 2017 10:29:50 BST
# gpg:                using RSA key 0xF30C38BD3F2FBE3C
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>"
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>"
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>"
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F  5173 F30C 38BD 3F2F BE3C

* remotes/vivier/tags/m68k-for-2.10-pull-request:
  target/m68k: implement rtd

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/m68k/cpu.c

@@ -130,6 +130,7 @@ static void m68020_cpu_initfn(Object *obj)
     m68k_set_feature(env, M68K_FEATURE_FPU);
     m68k_set_feature(env, M68K_FEATURE_CAS);
     m68k_set_feature(env, M68K_FEATURE_BKPT);
+    m68k_set_feature(env, M68K_FEATURE_RTD);
 }
 #define m68030_cpu_initfn m68020_cpu_initfn
 #define m68040_cpu_initfn m68020_cpu_initfn
@@ -151,6 +152,7 @@ static void m68060_cpu_initfn(Object *obj)
     m68k_set_feature(env, M68K_FEATURE_FPU);
     m68k_set_feature(env, M68K_FEATURE_CAS);
     m68k_set_feature(env, M68K_FEATURE_BKPT);
+    m68k_set_feature(env, M68K_FEATURE_RTD);
 }
 
 static void m5208_cpu_initfn(Object *obj)

target/m68k/cpu.h

@@ -251,6 +251,7 @@ enum m68k_features {
     M68K_FEATURE_FPU,
     M68K_FEATURE_CAS,
     M68K_FEATURE_BKPT,
+    M68K_FEATURE_RTD,
 };
 
 static inline int m68k_feature(CPUM68KState *env, int feature)

target/m68k/translate.c

@@ -2483,6 +2483,16 @@ DISAS_INSN(nop)
 {
 }
 
+DISAS_INSN(rtd)
+{
+    TCGv tmp;
+    int16_t offset = read_im16(env, s);
+
+    tmp = gen_load(s, OS_LONG, QREG_SP, 0);
+    tcg_gen_addi_i32(QREG_SP, QREG_SP, offset + 4);
+    gen_jmp(s, tmp);
+}
+
 DISAS_INSN(rts)
 {
     TCGv tmp;
@@ -4904,6 +4914,7 @@ void register_m68k_insns (CPUM68KState *env)
     BASE(nop,       4e71, ffff);
     BASE(stop,      4e72, ffff);
     BASE(rte,       4e73, ffff);
+    INSN(rtd,       4e74, ffff, RTD);
     BASE(rts,       4e75, ffff);
     INSN(movec,     4e7b, ffff, CF_ISA_A);
     BASE(jump,      4e80, ffc0);