My son started doing this when he turned 1 yo. It was his first tantrum-like behaviour and I was very unsettled by it at first (where was my sweet baby?)
I think it is a completely normal part of his development as he is learning to deal with anger and frustration. I would only worry if he is really hurting himself or if his behaviour lasts for an unreasonable time (a few minutes seems normal, but a child that is unable to let go after an hour for example could have issues with processing his feelings).
In our case, we chose to ignore this behaviour and he stopped completely within a few weeks. Like your son, he wasn't really hurting himself and was doing it mainly out of frustration when he was told "no". In my opinion he was also too young to be put in time out or other things like that, but it might not be your case.
Like any tantrum, you have to teach your son that this behaviour will not get him special attention from your part neither it will make you change your mind about what caused his frustration. Whatever technique you choose (ignoring, time out, etc.), stay calm and do not show that the behaviour upsets you. Keep interactions to a minimum until he is calm. Do not make it a big deal.
He is still young, but it might be a good time to start talking about emotions (read books, use charts where he can show how he feels, etc.). Also try to show him a few age appropriate ways to deal with anger (take deep breaths, encourage to use his words, have a cuddle with a favourite lovey, etc.). Finally, be a model for him in the way you deal with your own frustrations (no parent is perfect of course, but in the long run he will model his behaviour on yours).
For my son, managing anger is still to this day a challenge. He is 3 now and not banging his head on the floor anymore, but he always find new ways to act out when he is angry. It is a continuous work! Good luck!