HV: remove multiple exit/return in routines in the file of vlapic.c

To meet MISRA, remove few return in routines of vlapic.

Tracked-On: #861
Signed-off-by: Chaohong guo <chaohong.guo@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/arch/x86/guest/vlapic.c

@@ -111,17 +111,23 @@ static uint16_t vm_apicid2vcpu_id(struct acrn_vm *vm, uint8_t lapicid)
 {
 	uint16_t i;
 	struct acrn_vcpu *vcpu;
+	uint16_t cpu_id = INVALID_CPU_ID;
 
 	foreach_vcpu(i, vm, vcpu) {
 		const struct acrn_vlapic *vlapic = vcpu_vlapic(vcpu);
 		if (vlapic_get_apicid(vlapic) == lapicid) {
-			return vcpu->vcpu_id;
+			cpu_id = vcpu->vcpu_id;
+			break;
 		}
 	}
 
+	if (cpu_id == INVALID_CPU_ID) {
+		cpu_id = get_pcpu_nums();
 		pr_err("%s: bad lapicid %hhu", __func__, lapicid);
+	}
+
+	return cpu_id;
 
-	return get_pcpu_nums();
 }
 
 /*
@@ -626,10 +632,12 @@ vlapic_get_lvtptr(struct acrn_vlapic *vlapic, uint32_t offset)
 {
 	struct lapic_regs *lapic = &(vlapic->apic_page);
 	uint32_t i;
+	uint32_t *lvt_ptr;
 
 	switch (offset) {
 	case APIC_OFFSET_CMCI_LVT:
-		return &lapic->lvt_cmci.v;
+		lvt_ptr = &lapic->lvt_cmci.v;
+		break;
 	default:
 		/*
 		 * The function caller could guarantee the pre condition.
@@ -637,8 +645,10 @@ vlapic_get_lvtptr(struct acrn_vlapic *vlapic, uint32_t offset)
 		 * could be handled here.
 		 */
 		i = lvt_off_to_idx(offset);
-		return &(lapic->lvt[i].v);
+		lvt_ptr = &(lapic->lvt[i].v);
+		break;
 	}
+	return lvt_ptr;
 }
 
 static inline uint32_t
@@ -656,6 +666,7 @@ vlapic_lvt_write_handler(struct acrn_vlapic *vlapic, uint32_t offset)
 {
 	uint32_t *lvtptr, mask, val, idx;
 	struct lapic_regs *lapic;
+	bool error = false;
 
 	lapic = &(vlapic->apic_page);
 	lvtptr = vlapic_get_lvtptr(vlapic, offset);
@@ -695,7 +706,7 @@ vlapic_lvt_write_handler(struct acrn_vlapic *vlapic, uint32_t offset)
 					"vpic wire mode -> LAPIC");
 			} else {
 				pr_err("WARNING:invalid vpic wire mode change");
-				return;
+				error = true;
 			}
 		/* unmask -> mask: only from the vlapic LINT0-ExtINT enabled */
 		} else if (((last & APIC_LVT_M) == 0U) && ((val & APIC_LVT_M) != 0U)) {
@@ -713,10 +724,12 @@ vlapic_lvt_write_handler(struct acrn_vlapic *vlapic, uint32_t offset)
 		/* No action required. */
 	}
 
+	if (error == false) {
 		*lvtptr = val;
 		idx = lvt_off_to_idx(offset);
 		atomic_store32(&vlapic->lvt_last[idx], val);
 	}
+}
 
 static void
 vlapic_mask_lvts(struct acrn_vlapic *vlapic)
@@ -754,9 +767,7 @@ vlapic_fire_lvt(struct acrn_vlapic *vlapic, uint32_t lvt)
 	uint32_t vec, mode;
 	struct acrn_vcpu *vcpu = vlapic->vcpu;
 
-	if ((lvt & APIC_LVT_M) != 0U) {
+	if ((lvt & APIC_LVT_M) == 0U) {
-		return;
-	}
 
 		vec = lvt & APIC_LVT_VECTOR;
 		mode = lvt & APIC_LVT_DM;
@@ -776,7 +787,8 @@ vlapic_fire_lvt(struct acrn_vlapic *vlapic, uint32_t lvt)
 		default:
 			/* Other modes ignored */
 			pr_warn("func:%s other mode is not support\n",__func__);
-		return;
+			break;
+		}
 	}
 	return;
 }
@@ -903,7 +915,7 @@ vlapic_process_eoi(struct acrn_vlapic *vlapic)
 				/* hook to vIOAPIC */
 				vioapic_process_eoi(vlapic->vm, vector);
 			}
-			return;
+			break;
 		}
 	}
 
@@ -932,6 +944,7 @@ static int32_t
 vlapic_trigger_lvt(struct acrn_vlapic *vlapic, uint32_t vector)
 {
 	uint32_t lvt;
+	int32_t ret = 0;
 	struct acrn_vcpu *vcpu = vlapic->vcpu;
 
 	if (vlapic_enabled(vlapic) == false) {
@@ -955,8 +968,7 @@ vlapic_trigger_lvt(struct acrn_vlapic *vlapic, uint32_t vector)
 			 */
 			break;
 		}
-		return 0;
+	} else {
-	}
 
 		switch (vector) {
 		case APIC_LVT_LINT0:
@@ -983,14 +995,20 @@ vlapic_trigger_lvt(struct acrn_vlapic *vlapic, uint32_t vector)
 			lvt = vlapic_get_lvt(vlapic, APIC_OFFSET_CMCI_LVT);
 			break;
 		default:
-		return -EINVAL;
+			lvt = 0U; /* make MISRA happy */
+			ret =  -EINVAL;
+			break;
 		}
+
+		if (ret == 0) {
 			if (vector < 16U) {
 				vlapic_set_error(vlapic, APIC_ESR_RECEIVE_ILLEGAL_VECTOR);
 			} else {
 				vlapic_fire_lvt(vlapic, lvt);
 			}
-	return 0;
+		}
+	}
+	return ret;
 }
 
 /*
@@ -1167,9 +1185,7 @@ vlapic_process_init_sipi(struct acrn_vcpu* target_vcpu, uint32_t mode,
 				uint32_t icr_low, uint16_t vcpu_id)
 {
 	if (mode == APIC_DELMODE_INIT) {
-		if ((icr_low & APIC_LEVEL_MASK) == APIC_LEVEL_DEASSERT) {
+		if ((icr_low & APIC_LEVEL_MASK) != APIC_LEVEL_DEASSERT) {
-			return;
-		}
 
 			dev_dbg(ACRN_DBG_LAPIC,
 				"Sending INIT from VCPU %hu to %hu",
@@ -1183,12 +1199,11 @@ vlapic_process_init_sipi(struct acrn_vcpu* target_vcpu, uint32_t mode,
 			 * wait-for-SIPI state.
 			*/
 			target_vcpu->arch.nr_sipi = 1U;
+		}
 	} else if (mode == APIC_DELMODE_STARTUP) {
 		/* Ignore SIPIs in any state other than wait-for-SIPI */
-		if ((target_vcpu->state != VCPU_INIT) ||
+		if ((target_vcpu->state == VCPU_INIT) &&
-			(target_vcpu->arch.nr_sipi == 0U)) {
+			(target_vcpu->arch.nr_sipi != 0U)) {
-				return;
-		}
 
 			dev_dbg(ACRN_DBG_LAPIC,
 				"Sending SIPI from VCPU %hu to %hu with vector %u",
@@ -1196,9 +1211,7 @@ vlapic_process_init_sipi(struct acrn_vcpu* target_vcpu, uint32_t mode,
 				(icr_low & APIC_VECTOR_MASK));
 
 			target_vcpu->arch.nr_sipi--;
-		if (target_vcpu->arch.nr_sipi > 0U) {
+			if (target_vcpu->arch.nr_sipi <= 0U) {
-			return;
-		}
 
 				pr_err("Start Secondary VCPU%hu for VM[%d]...",
 					target_vcpu->vcpu_id,
@@ -1207,6 +1220,9 @@ vlapic_process_init_sipi(struct acrn_vcpu* target_vcpu, uint32_t mode,
 				schedule_vcpu(target_vcpu);
 			}
 		}
+	}
+	return;
+}
 
 static int32_t
 vlapic_icrlo_write_handler(struct acrn_vlapic *vlapic)
@@ -1320,10 +1336,11 @@ vlapic_pending_intr(const struct acrn_vlapic *vlapic, uint32_t *vecptr)
 	const struct lapic_regs *lapic = &(vlapic->apic_page);
 	uint32_t i, vector, val, bitpos;
 	const struct lapic_reg *irrptr;
+	int32_t	ret = 0;
 
 	if (is_apicv_intr_delivery_supported()) {
-		return apicv_pending_intr(vlapic);
+		ret = apicv_pending_intr(vlapic);
-	}
+	} else {
 
 		irrptr = &lapic->irr[0];
 
@@ -1338,12 +1355,13 @@ vlapic_pending_intr(const struct acrn_vlapic *vlapic, uint32_t *vecptr)
 					if (vecptr != NULL) {
 						*vecptr = vector;
 					}
-				return 1;
+					ret = 1;
 				}
 				break;
 			}
 		}
-	return 0;
+	}
+	return ret;
 }
 
 /**