the cost of EXPORT_SYMBOL_GPL

[Martin Kaiser]

Hello Greg and all,

Thus wrote Greg KH (greg at kroah.com):

> Please do not do that. There are valid kernel apis to grant access to
> registers easily,

the most simple case would be a "reset reason" register within the
chip's address space. A hand-crafted driver would ioremap the region and
implement a sysfs show method that reads the register.

What do you recommend for providing read access to such a register
via sysfs? Is this a job for the userspace I/O (UIO) subsystem?

Thanks,
Martin