How can I test if a physical address is already mapped or not.

[StephanT]

>>When you say an access to physical address, how are you managing to
>>access the physical address directly?

Like this:

unsigned long    * const pReg = (unsigned long*) 0XC0000000 ; 

printk( KERN_INFO"** read (%p) %08lX.\n", pReg, *pReg) ;