Disabling interrupts on one device from the driver of another
I am kind of stuck at this point.
The situation is thus :
I have two devices A and B. The moment a certain interrupt X happens on device A i need to disable device B from doing any further interrupts. And then once the interrupt X on A is cleared i need to enable interrupts on B. This has to be done using a bunch of ioctl() calls. I know the parameters to pass (ie, the file descriptor and so on). I also have functions that will give me the major and the minor number of the associated device (ie. the particular instance of B).
My problem is how do i call those functions on the instance of B from the driver(code) of A. Apparently, EXPORT_SYMBOL_NOVERS or a variant of that is supposed to export the specified symbol to the kernel.
a) where do i put this EXPORT_SYMBOL_NOVERS statement (in the driver code of A or driver code of B) and what are the necessary generic conditions and implications of this statement?
I am fairly a newbie to the world of device drivers in linux and i would be grateful for any help on this.