title: how to allocate non-cacheable physical memory in kernel?
body: <p>if want to allocate non-cacheable physical memory (DRAM) for usage in the driver,
  (ie. don't want the data being cached into the CPU's data cache when
  the data are accessed) how could I do this?</p>
  
  <p>there are functions like kmalloc(), get_free_pages, vmalloc, etc,
  but seems like that I can't specify if the data can be cached or not using these functions?
  any suggestion on how to do it?</p>
  
  <p>thanks!</p>