Re: [RFC] dma-mapping: fix dma_common_mmap() for ARC

2016-10-30 Thread Catalin Marinas
On Wed, Oct 26, 2016 at 10:22:44PM +0300, Alexey Brodkin wrote: > >8--- > arc_dma_alloc() > ioremap_nocache() AKA ioremap() > ioremap_prot() > get_vm_area() + ioremap_page_range() on obtained vaddr > >8-

[RFC] dma-mapping: fix dma_common_mmap() for ARC

2016-10-26 Thread Alexey Brodkin
ARC CPU with enabled MMU sees entire 32-bit address space divided in 2 big parts: 1) 0 - 0x7fff_ (lower 2Gb): translated memory I.e. all reads/writes from/to this region go through MMU and after translation land somewhere in physical memory. 2) 0x8000_ - 0x_: untranslated