disas: arm: QOMify target specific disas setup

Move the target_disas() ARM specifics to the QOM disas_set_info hook
and delete the ARM specific code in disas.c.

This has the extra advantage of the more fully featured target_disas()
implementation now applying to monitor_disas().

Currently, target_disas() has multi-endian, thumb and AArch64
support whereas the existing monitor_disas() support only has vanilla
AA32 support.

E.G. Running an AA64 linux kernel the following -d in_asm disas happens
(taget_disas()):

IN:
0x0000000040000000:  580000c0      ldr x0, pc+24 (addr 0x40000018)
0x0000000040000004:  aa1f03e1      mov x1, xzr

However before this patch, disasing the same from the monitor:

(qemu) xp/i 0x40000000
0x0000000040000000:  580000c0      stmdapl  r0, {r6, r7}

After this patch:
(qemu) xp/i 0x40000000
0x0000000040000000:  580000c0      ldr x0, pc+24 (addr 0x40000018)
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: NAndreas Färber <afaerber@suse.de>

disas.c

@@ -151,14 +151,6 @@ bfd_vma bfd_getb16 (const bfd_byte *addr)
   return (bfd_vma) v;
 }
 
-#ifdef TARGET_ARM
-static int
-print_insn_thumb1(bfd_vma pc, disassemble_info *info)
-{
-  return print_insn_arm(pc | 1, info);
-}
-#endif
-
 static int print_insn_objdump(bfd_vma pc, disassemble_info *info,
                               const char *prefix)
 {
@@ -191,7 +183,6 @@ static int print_insn_od_target(bfd_vma pc, disassemble_info *info)
 /* Disassemble this for me please... (debugging). 'flags' has the following
    values:
     i386 - 1 means 16 bit code, 2 means 64 bit code
-    arm  - bit 0 = thumb, bit 1 = reverse endian, bit 2 = A64
     ppc  - bits 0:15 specify (optionally) the machine instruction set;
            bit 16 indicates little endian.
     other targets - unused
@@ -231,27 +222,6 @@ void target_disas(FILE *out, CPUState *cpu, target_ulong code,
         s.info.mach = bfd_mach_i386_i386;
     }
     s.info.print_insn = print_insn_i386;
-#elif defined(TARGET_ARM)
-    if (flags & 4) {
-        /* We might not be compiled with the A64 disassembler
-         * because it needs a C++ compiler; in that case we will
-         * fall through to the default print_insn_od case.
-         */
-#if defined(CONFIG_ARM_A64_DIS)
-        s.info.print_insn = print_insn_arm_a64;
-#endif
-    } else if (flags & 1) {
-        s.info.print_insn = print_insn_thumb1;
-    } else {
-        s.info.print_insn = print_insn_arm;
-    }
-    if (flags & 2) {
-#ifdef TARGET_WORDS_BIGENDIAN
-        s.info.endian = BFD_ENDIAN_LITTLE;
-#else
-        s.info.endian = BFD_ENDIAN_BIG;
-#endif
-    }
 #elif defined(TARGET_SPARC)
     s.info.print_insn = print_insn_sparc;
 #ifdef TARGET_SPARC64
@@ -488,8 +458,6 @@ void monitor_disas(Monitor *mon, CPUState *cpu,
         s.info.mach = bfd_mach_i386_i386;
     }
     s.info.print_insn = print_insn_i386;
-#elif defined(TARGET_ARM)
-    s.info.print_insn = print_insn_arm;
 #elif defined(TARGET_ALPHA)
     s.info.print_insn = print_insn_alpha;
 #elif defined(TARGET_SPARC)

target-arm/cpu.c

@@ -382,6 +382,39 @@ static inline void unset_feature(CPUARMState *env, int feature)
     env->features &= ~(1ULL << feature);
 }
 
+static int
+print_insn_thumb1(bfd_vma pc, disassemble_info *info)
+{
+  return print_insn_arm(pc | 1, info);
+}
+
+static void arm_disas_set_info(CPUState *cpu, disassemble_info *info)
+{
+    ARMCPU *ac = ARM_CPU(cpu);
+    CPUARMState *env = &ac->env;
+
+    if (is_a64(env)) {
+        /* We might not be compiled with the A64 disassembler
+         * because it needs a C++ compiler. Leave print_insn
+         * unset in this case to use the caller default behaviour.
+         */
+#if defined(CONFIG_ARM_A64_DIS)
+        info->print_insn = print_insn_arm_a64;
+#endif
+    } else if (env->thumb) {
+        info->print_insn = print_insn_thumb1;
+    } else {
+        info->print_insn = print_insn_arm;
+    }
+    if (env->bswap_code) {
+#ifdef TARGET_WORDS_BIGENDIAN
+        info->endian = BFD_ENDIAN_LITTLE;
+#else
+        info->endian = BFD_ENDIAN_BIG;
+#endif
+    }
+}
+
 #define ARM_CPUS_PER_CLUSTER 8
 
 static void arm_cpu_initfn(Object *obj)
@@ -1368,6 +1401,8 @@ static void arm_cpu_class_init(ObjectClass *oc, void *data)
     cc->gdb_core_xml_file = "arm-core.xml";
     cc->gdb_stop_before_watchpoint = true;
     cc->debug_excp_handler = arm_debug_excp_handler;
+
+    cc->disas_set_info = arm_disas_set_info;
 }
 
 static void cpu_register(const ARMCPUInfo *info)