target/arm: Make Cortex-M3 and M4 default to 8 PMSA regions

The Cortex-M3 and M4 CPUs always have 8 PMSA MPU regions (this isn't
a configurable option for the hardware).  Make the default value of
the pmsav7-dregion property be set per-cpu, so we don't need to have
every user of these CPUs set it manually.  (The existing default of
16 is correct for the other PMSAv7 core, the Cortex-R5.)

This fixes a bug where we were creating the M3 and M4 with
too many regions; most guest software would not notice or
care, though, since it would just not use the registers
associated with the unexpected extra regions.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 1499788408-10096-4-git-send-email-peter.maydell@linaro.org

target/arm/cpu.c

@@ -543,8 +543,15 @@ static Property arm_cpu_has_pmu_property =
 static Property arm_cpu_has_mpu_property =
             DEFINE_PROP_BOOL("has-mpu", ARMCPU, has_mpu, true);
 
+/* This is like DEFINE_PROP_UINT32 but it doesn't set the default value,
+ * because the CPU initfn will have already set cpu->pmsav7_dregion to
+ * the right value for that particular CPU type, and we don't want
+ * to override that with an incorrect constant value.
+ */
 static Property arm_cpu_pmsav7_dregion_property =
-            DEFINE_PROP_UINT32("pmsav7-dregion", ARMCPU, pmsav7_dregion, 16);
+            DEFINE_PROP_UNSIGNED_NODEFAULT("pmsav7-dregion", ARMCPU,
+                                           pmsav7_dregion,
+                                           qdev_prop_uint32, uint32_t);
 
 static void arm_cpu_post_init(Object *obj)
 {
@@ -1054,6 +1061,7 @@ static void cortex_m3_initfn(Object *obj)
     set_feature(&cpu->env, ARM_FEATURE_V7);
     set_feature(&cpu->env, ARM_FEATURE_M);
     cpu->midr = 0x410fc231;
+    cpu->pmsav7_dregion = 8;
 }
 
 static void cortex_m4_initfn(Object *obj)
@@ -1064,6 +1072,7 @@ static void cortex_m4_initfn(Object *obj)
     set_feature(&cpu->env, ARM_FEATURE_M);
     set_feature(&cpu->env, ARM_FEATURE_THUMB_DSP);
     cpu->midr = 0x410fc240; /* r0p0 */
+    cpu->pmsav7_dregion = 8;
 }
 static void arm_v7m_class_init(ObjectClass *oc, void *data)
 {
@@ -1112,6 +1121,7 @@ static void cortex_r5_initfn(Object *obj)
     cpu->id_isar4 = 0x0010142;
     cpu->id_isar5 = 0x0;
     cpu->mp_is_up = true;
+    cpu->pmsav7_dregion = 16;
     define_arm_cp_regs(cpu, cortexr5_cp_reginfo);
 }