[qemu-s390x] [PATCH] s390x: Cleanup cpu resets

[Janosch Frank]

S390x CPU resets are cascading, hence initial reset and clear reset
need to do all things a plain reset does.

Let's make sure that's done and consolidate some reset code.
Also let's always explicitly set boolean cpu state members to their
type value (e.g. bpbc).

Signed-off-by: Janosch Frank <address@hidden>
---
 target/s390x/cpu.c | 79 +++++++++++++++++++++++++++---------------------------
 1 file changed, 39 insertions(+), 40 deletions(-)

diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
index f2d93644d5..b96fbe4838 100644
--- a/target/s390x/cpu.c
+++ b/target/s390x/cpu.c
@@ -81,18 +81,44 @@ static void s390_cpu_load_normal(CPUState *s)
 }
 #endif
 
+static void s390_reset_pre_memset(CPUState *s) {
+    S390CPU *cpu = S390_CPU(s);
+    S390CPUClass *scc = S390_CPU_GET_CLASS(cpu);
+
+    scc->parent_reset(s);
+    cpu->env.sigp_order = 0;
+    s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu);
+}
+
+/* Values that need to be set after the memset for all reset types */
+static void s390_reset_post_memset_normal(CPUS390XState *env) {
+    env->pfault_token = -1UL;
+    env->bpbc = false;
+}
+
+/* Values that need to be reset additionally for initial and clear resets */
+static void s390_reset_post_memset_initial(CPUS390XState *env)
+{
+    s390_reset_post_memset_normal(env);
+    /* architectured initial values for CR 0 and 14 */
+    env->cregs[0] = CR0_RESET;
+    env->cregs[14] = CR14_RESET;
+
+    /* architectured initial value for Breaking-Event-Address register */
+    env->gbea = 1;
+    /* tininess for underflow is detected before rounding */
+    set_float_detect_tininess(float_tininess_before_rounding,
+                              &env->fpu_status);
+}
+
 /* S390CPUClass::cpu_reset() */
 static void s390_cpu_reset(CPUState *s)
 {
     S390CPU *cpu = S390_CPU(s);
-    S390CPUClass *scc = S390_CPU_GET_CLASS(cpu);
     CPUS390XState *env = &cpu->env;
 
-    env->pfault_token = -1UL;
-    env->bpbc = false;
-    scc->parent_reset(s);
-    cpu->env.sigp_order = 0;
-    s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu);
+    s390_reset_pre_memset(s);
+    s390_reset_post_memset_normal(env);
 }
 
 /* S390CPUClass::initial_reset() */
@@ -101,24 +127,12 @@ static void s390_cpu_initial_reset(CPUState *s)
     S390CPU *cpu = S390_CPU(s);
     CPUS390XState *env = &cpu->env;
 
-    s390_cpu_reset(s);
+    s390_reset_pre_memset(s);
     /* initial reset does not clear everything! */
     memset(&env->start_initial_reset_fields, 0,
         offsetof(CPUS390XState, end_reset_fields) -
         offsetof(CPUS390XState, start_initial_reset_fields));
-
-    /* architectured initial values for CR 0 and 14 */
-    env->cregs[0] = CR0_RESET;
-    env->cregs[14] = CR14_RESET;
-
-    /* architectured initial value for Breaking-Event-Address register */
-    env->gbea = 1;
-
-    env->pfault_token = -1UL;
-
-    /* tininess for underflow is detected before rounding */
-    set_float_detect_tininess(float_tininess_before_rounding,
-                              &env->fpu_status);
+    s390_reset_post_memset_initial(env);
 
     /* Reset state inside the kernel that we cannot access yet from QEMU. */
     if (kvm_enabled()) {
@@ -127,22 +141,16 @@ static void s390_cpu_initial_reset(CPUState *s)
 }
 
 /* CPUClass:reset() */
-static void s390_cpu_full_reset(CPUState *s)
+static void s390_cpu_clear_reset(CPUState *s)
 {
     S390CPU *cpu = S390_CPU(s);
-    S390CPUClass *scc = S390_CPU_GET_CLASS(cpu);
     CPUS390XState *env = &cpu->env;
 
-    scc->parent_reset(s);
-    cpu->env.sigp_order = 0;
-    s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu);
-
+    s390_reset_pre_memset(s);
     memset(env, 0, offsetof(CPUS390XState, end_reset_fields));
+    s390_reset_post_memset_initial(env);
 
-    /* architectured initial values for CR 0 and 14 */
-    env->cregs[0] = CR0_RESET;
-    env->cregs[14] = CR14_RESET;
-
+    /* Specific to clear reset */
 #if defined(CONFIG_USER_ONLY)
     /* user mode should always be allowed to use the full FPU */
     env->cregs[0] |= CR0_AFP;
@@ -151,15 +159,6 @@ static void s390_cpu_full_reset(CPUState *s)
     }
 #endif
 
-    /* architectured initial value for Breaking-Event-Address register */
-    env->gbea = 1;
-
-    env->pfault_token = -1UL;
-
-    /* tininess for underflow is detected before rounding */
-    set_float_detect_tininess(float_tininess_before_rounding,
-                              &env->fpu_status);
-
     /* Reset state inside the kernel that we cannot access yet from QEMU. */
     if (kvm_enabled()) {
         kvm_s390_reset_vcpu(cpu);
@@ -472,7 +471,7 @@ static void s390_cpu_class_init(ObjectClass *oc, void *data)
 #endif
     scc->cpu_reset = s390_cpu_reset;
     scc->initial_cpu_reset = s390_cpu_initial_reset;
-    cc->reset = s390_cpu_full_reset;
+    cc->reset = s390_cpu_clear_reset;
     cc->class_by_name = s390_cpu_class_by_name,
     cc->has_work = s390_cpu_has_work;
 #ifdef CONFIG_TCG
-- 
2.14.3