KVM: x86: Move x2APIC ICR helper above kvm_apic_write_nodecode()

Hoist kvm_x2apic_icr_write() above kvm_apic_write_nodecode() so that a
local helper to _read_ the x2APIC ICR can be added and used in the
nodecode path without needing a forward declaration.

No functional change intended.

Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Sean Christopherson <[e-mail]>

arch/x86/kvm/lapic.c

···
 }
 EXPORT_SYMBOL_GPL(kvm_lapic_set_eoi);
 
+#define X2APIC_ICR_RESERVED_BITS (GENMASK_ULL(31, 20) | GENMASK_ULL(17, 16) | BIT(13))
+
+int kvm_x2apic_icr_write(struct kvm_lapic *apic, u64 data)
+{
+	if (data & X2APIC_ICR_RESERVED_BITS)
+		return 1;
+
+	/*
+	 * The BUSY bit is reserved on both Intel and AMD in x2APIC mode, but
+	 * only AMD requires it to be zero, Intel essentially just ignores the
+	 * bit.  And if IPI virtualization (Intel) or x2AVIC (AMD) is enabled,
+	 * the CPU performs the reserved bits checks, i.e. the underlying CPU
+	 * behavior will "win".  Arbitrarily clear the BUSY bit, as there is no
+	 * sane way to provide consistent behavior with respect to hardware.
+	 */
+	data &= ~APIC_ICR_BUSY;
+
+	kvm_apic_send_ipi(apic, (u32)data, (u32)(data >> 32));
+	kvm_lapic_set_reg64(apic, APIC_ICR, data);
+	trace_kvm_apic_write(APIC_ICR, data);
+	return 0;
+}
+
 /* emulate APIC access in a trap manner */
 void kvm_apic_write_nodecode(struct kvm_vcpu *vcpu, u32 offset)
 {
···
 	}
 
 	vcpu->arch.apic->vapic_addr = vapic_addr;
-	return 0;
-}
-
-#define X2APIC_ICR_RESERVED_BITS (GENMASK_ULL(31, 20) | GENMASK_ULL(17, 16) | BIT(13))
-
-int kvm_x2apic_icr_write(struct kvm_lapic *apic, u64 data)
-{
-	if (data & X2APIC_ICR_RESERVED_BITS)
-		return 1;
-
-	/*
-	 * The BUSY bit is reserved on both Intel and AMD in x2APIC mode, but
-	 * only AMD requires it to be zero, Intel essentially just ignores the
-	 * bit.  And if IPI virtualization (Intel) or x2AVIC (AMD) is enabled,
-	 * the CPU performs the reserved bits checks, i.e. the underlying CPU
-	 * behavior will "win".  Arbitrarily clear the BUSY bit, as there is no
-	 * sane way to provide consistent behavior with respect to hardware.
-	 */
-	data &= ~APIC_ICR_BUSY;
-
-	kvm_apic_send_ipi(apic, (u32)data, (u32)(data >> 32));
-	kvm_lapic_set_reg64(apic, APIC_ICR, data);
-	trace_kvm_apic_write(APIC_ICR, data);
 	return 0;
 }