> When one does an ioremap the kernel maps the given address into its > address space and then returns an address. Is there a way to reverse > this process... > > Normally x = ioremap( y, size ); > Is there a way to retrieve y, given x? You'll have to read the corresponding page table entry. It will be very architecture specific. For example, here is (approximately) what you need to do on i386: pgd_index = x / PGDIR_SIZE pgd = swapper_pg_dir[pgd_index] & 0xfffff000 (this mask is probably defined somewhere. PGD_MASK maybe??) pte_index = ( x % PGDIR_SIZE ) / PAGE_SIZE pte = *(pgd + pte_index) & 0xfffff000 'pte' gives the physical address that x maps to. If there is a better (or easier) way, I too would like to know :) Hope this helps, Ravi. __________________________________________________ Do You Yahoo!? Yahoo! Tax Center - online filing with TurboTax http://taxes.yahoo.com/ -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
