[qemu-s390x] [PATCH v2] 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 | 123 ++++++++++++++++++++++++-----------------------------
 1 file changed, 55 insertions(+), 68 deletions(-)

diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
index f2d93644d5..2619c60236 100644
--- a/target/s390x/cpu.c
+++ b/target/s390x/cpu.c
@@ -81,89 +81,76 @@ static void s390_cpu_load_normal(CPUState *s)
 }
 #endif
 
-/* S390CPUClass::cpu_reset() */
-static void s390_cpu_reset(CPUState *s)
+enum {
+    S390_CPU_RESET_NORMAL,
+    S390_CPU_RESET_INITIAL,
+    S390_CPU_RESET_CLEAR,
+};
+
+static void s390_cpu_reset(CPUState *s, uint8_t type)
 {
     S390CPU *cpu = S390_CPU(s);
-    S390CPUClass *scc = S390_CPU_GET_CLASS(cpu);
     CPUS390XState *env = &cpu->env;
+    S390CPUClass *scc = S390_CPU_CLASS(cpu);
 
-    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);
-}
 
-/* S390CPUClass::initial_reset() */
-static void s390_cpu_initial_reset(CPUState *s)
-{
-    S390CPU *cpu = S390_CPU(s);
-    CPUS390XState *env = &cpu->env;
-
-    s390_cpu_reset(s);
-    /* initial reset does not clear everything! */
-    memset(&env->start_initial_reset_fields, 0,
+    /* Clear registers */
+    if (type == S390_CPU_RESET_INITIAL) {
+        /* initial reset does not clear everything! */
+        memset(&env->start_initial_reset_fields, 0,
         offsetof(CPUS390XState, end_reset_fields) -
         offsetof(CPUS390XState, start_initial_reset_fields));
+    } else if (type == S390_CPU_RESET_INITIAL) {
+        memset(env, 0, offsetof(CPUS390XState, end_reset_fields));
+    }
 
-    /* architectured initial values for CR 0 and 14 */
-    env->cregs[0] = CR0_RESET;
-    env->cregs[14] = CR14_RESET;
+    /* Set initial values after clearing */
+    switch (type) {
+    case S390_CPU_RESET_CLEAR:
+#if defined(CONFIG_USER_ONLY)
+        /* user mode should always be allowed to use the full FPU */
+        env->cregs[0] |= CR0_AFP;
+        if (s390_has_feat(S390_FEAT_VECTOR)) {
+            env->cregs[0] |= CR0_VECTOR;
+        }
+#endif
+    case S390_CPU_RESET_INITIAL:
+        /* 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);
-
-    /* Reset state inside the kernel that we cannot access yet from QEMU. */
-    if (kvm_enabled()) {
-        kvm_s390_reset_vcpu(cpu);
+        /* 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);
+        /* Reset state inside the kernel that we cannot access yet from QEMU. 
*/
+        if (kvm_enabled()) {
+            kvm_s390_reset_vcpu(cpu);
+        }
+    case S390_CPU_RESET_NORMAL:
+        env->pfault_token = -1UL;
+        env->bpbc = false;
+        break;
     }
 }
 
-/* CPUClass:reset() */
-static void s390_cpu_full_reset(CPUState *s)
+static void s390_cpu_reset_normal(CPUState *s)
 {
-    S390CPU *cpu = S390_CPU(s);
-    S390CPUClass *scc = S390_CPU_GET_CLASS(cpu);
-    CPUS390XState *env = &cpu->env;
+    return s390_cpu_reset(s, S390_CPU_RESET_NORMAL);
+}
 
-    scc->parent_reset(s);
-    cpu->env.sigp_order = 0;
-    s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu);
+static void s390_cpu_reset_initial(CPUState *s)
+{
+    return s390_cpu_reset(s, S390_CPU_RESET_INITIAL);
+}
 
-    memset(env, 0, offsetof(CPUS390XState, end_reset_fields));
-
-    /* architectured initial values for CR 0 and 14 */
-    env->cregs[0] = CR0_RESET;
-    env->cregs[14] = CR14_RESET;
-
-#if defined(CONFIG_USER_ONLY)
-    /* user mode should always be allowed to use the full FPU */
-    env->cregs[0] |= CR0_AFP;
-    if (s390_has_feat(S390_FEAT_VECTOR)) {
-        env->cregs[0] |= CR0_VECTOR;
-    }
-#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);
-    }
+static void s390_cpu_reset_clear(CPUState *s)
+{
+    return s390_cpu_reset(s, S390_CPU_RESET_CLEAR);
 }
 
 #if !defined(CONFIG_USER_ONLY)
@@ -470,9 +457,9 @@ static void s390_cpu_class_init(ObjectClass *oc, void *data)
 #if !defined(CONFIG_USER_ONLY)
     scc->load_normal = s390_cpu_load_normal;
 #endif
-    scc->cpu_reset = s390_cpu_reset;
-    scc->initial_cpu_reset = s390_cpu_initial_reset;
-    cc->reset = s390_cpu_full_reset;
+    scc->cpu_reset = s390_cpu_reset_normal;
+    scc->initial_cpu_reset = s390_cpu_reset_initial;
+    cc->reset = s390_cpu_reset_clear;
     cc->class_by_name = s390_cpu_class_by_name,
     cc->has_work = s390_cpu_has_work;
 #ifdef CONFIG_TCG
-- 
2.14.3