How to do concurrent control when accessing many registers by ioctl???

[yihect]

Hi, all:
    Im my device, there are many registers resider in several banks, these 
registers are all
accessed by one IOCTL cmd in my driver. And there are 2 or 3 tasks will access 
these registers simultaneously in app layer.

    So, my question is: Is there some common model to do this kind of 
concurrent control? Is there some sample as reference?
Any suggestion will be welcome also.