On Thu, Oct 03, 2013 at 11:48:34AM -0700, David Daney wrote: > I wonder, how does /dev/mem handle it? We should probably do what > the mem driver does for this. /dev/mem is converting physical address to virtual addresses using xlate_dev_mem_ptr() which is defined as: #define xlate_dev_mem_ptr(p) __va(p) which obviously is suffering from similar problems as Prem's suggested patch. Fortunately /dev/(k)mem have pretty much gotten out of fashion ;-) The x86 implementation of xlate_dev_mem_ptr() is based on ioremap_cache() which may be x86-specific - but very handy in situations like this and there might also be devices which want to be mapped cached. I'm considering to implement it since ages. I just don't want a whole flood of new cache modes like ioremap_uncached_accelerated() or maybe ioremap_writeback_on_sunday_afternoons_only() ;-) Ralf
