[PATCHv6 2/2] ARM: dma-mapping: remove custom consistent dma region

On Tue, Aug 21, 2012 at 02:22:35PM +0300, Hiroshi Doyu wrote:

The following "__get_vm_area_node()" can take gfp_mask, it means that
this function is expected to be called from atomic context, but why
it's _NOT_ allowed _ONLY_ from interrupt context?

One reason is it takes read/write locks without using the IRQ safe
versions for starters (vmap_area_lock and vmlist_lock).  I don't see
any other reasons in that bit of code though.