Use value from void in onCreate inputfilter

I'm working on an app which generates swap space on the /cache partition of Android devices. It can already calculate the maximum size of the swap, but the maximum amount one can enter is still static.

For the EditText InputFilter I use this:

@Override
protected void onCreate(Bundle savedInstanceState) {  
    ... 
    final EditText mb = (EditText) findViewById(R.id.editText1);
    mb.setFilters(new InputFilter[]{ new InputFilterMinMax("1", "120")});
    ...
}

And my void is this:

// Check Disk Space and display
void readSpace(){
    execCommandLine("mount -o rw,remount /cache");
    File spacechecker = new File("/cache");
    long totalSpace = spacechecker.getTotalSpace();
    long usableSpace = spacechecker.getUsableSpace();

    TextView tsp = (TextView) findViewById(R.id.AmmountTotal);
    tsp.setText(totalSpace /1024 /1024 + " MB");

    TextView usp = (TextView) findViewById(R.id.AmmountAvailable);
    usp.setText(usableSpace /1024 /1024 + " MB");

    TextView rsp = (TextView) findViewById(R.id.AmmountRecommended);
    rsp.setText(usableSpace /1024 /1024 -20 + " MB");
}

How can I get the 120 to be the value of long usableSpace in MB?

Thanks in advance

If I'm understanding this correctly, you want to change the upper limit of your TextView, yes?

  mb.setFilters(new InputFilter[]{ new InputFilterMinMax("1", Long.toString(usableSpace / 1024 / 1024))});