You took some good pictures... Thanks.
From the horizontal white line I see along your cheek, it looks very much like what we as Dentist often see. And often the white area is due to inadvertent cheek biting, either in one's sleep, or perhaps, even being cognitive of doing so (but you would know if you were doing such cognitively). Often called Hyperkeratinized Epithelium. It generally subsides, once the irritant goes away. In this case, if we deemed the causation to be cheek biting, and presumably at night, one could wear an inexpensive night guard - which one could buy at a pharmacy, or have one's Dentist make. I can't see any photo angles of your gums, but smoking is often also a problem which causes whitish looking patches - which will also subside (almost always) once the irritant (smoking) is removed. Sorry, easier said than done on that subject - right?
Lastly, if it were me, I'd attempt to slowly taper off, and/or quit smoking. But, I realize that is NOT easy. However, it may be partially due to smoking - the white on the gums (and cheek too), and it may well be partially or totally (cheek only) caused by inadvertently chewing on the cheek. But the bot***** *****ne: I do NOT believe, from the pictures you sent me, that you have anything serious to be concerned about. And, as mentioned above, remove the smoking, and possibly a night guard. One or both are the likely causes of your white look which you are concerned about. A final note: If you alleviate the smoke and/or try a nightguard - then you've fixed the problem, obviously. If, by some unusual chance the above methods do not alleviate your white look - you could always get it biopsied by your Dentist, and within 48 hours have 100% perfect confirmation of what the white area is. I do NOT think you will need to get a biopsy though. I believe you have hyperkeratinized epithelium, brought about by either smoke and/or chewing of the cheek or both. I hope this helps you Sir!