hw/i8042: Refactor trap handler

With the planned retirement of the special ioport emulation code, we
need to provide an emulation function compatible with the MMIO
prototype.

Adjust the trap handler to use that new function, and provide shims to
implement the old ioport interface, for now.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20210315153350.19988-7-andre.przywara@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
diff --git a/hw/i8042.c b/hw/i8042.c
index 7d1f977..ab86666 100644
--- a/hw/i8042.c
+++ b/hw/i8042.c
@@ -292,52 +292,52 @@
 	};
 }
 
+static void kbd_io(struct kvm_cpu *vcpu, u64 addr, u8 *data, u32 len,
+		   u8 is_write, void *ptr)
+{
+	u8 value;
+
+	if (is_write)
+		value = ioport__read8(data);
+
+	switch (addr) {
+	case I8042_COMMAND_REG:
+		if (is_write)
+			kbd_write_command(vcpu->kvm, value);
+		else
+			value = kbd_read_status();
+		break;
+	case I8042_DATA_REG:
+		if (is_write)
+			kbd_write_data(value);
+		else
+			value = kbd_read_data();
+		break;
+	case I8042_PORT_B_REG:
+		if (!is_write)
+			value = 0x20;
+		break;
+	default:
+		return;
+	}
+
+	if (!is_write)
+		ioport__write8(data, value);
+}
+
 /*
  * Called when the OS has written to one of the keyboard's ports (0x60 or 0x64)
  */
 static bool kbd_in(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
 {
-	switch (port) {
-	case I8042_COMMAND_REG: {
-		u8 value = kbd_read_status();
-		ioport__write8(data, value);
-		break;
-	}
-	case I8042_DATA_REG: {
-		u8 value = kbd_read_data();
-		ioport__write8(data, value);
-		break;
-	}
-	case I8042_PORT_B_REG: {
-		ioport__write8(data, 0x20);
-		break;
-	}
-	default:
-		return false;
-	}
+	kbd_io(vcpu, port, data, size, false, NULL);
 
 	return true;
 }
 
 static bool kbd_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
 {
-	switch (port) {
-	case I8042_COMMAND_REG: {
-		u8 value = ioport__read8(data);
-		kbd_write_command(vcpu->kvm, value);
-		break;
-	}
-	case I8042_DATA_REG: {
-		u8 value = ioport__read8(data);
-		kbd_write_data(value);
-		break;
-	}
-	case I8042_PORT_B_REG: {
-		break;
-	}
-	default:
-		return false;
-	}
+	kbd_io(vcpu, port, data, size, true, NULL);
 
 	return true;
 }