tree 627d3eafefd38b031e776b48d8d04d764912ec92
parent 43377453af83b8ff8c1c731da1508bd6b84ebfea
author Nicolas Pitre <nico@cam.org> 1220990053 -0400
committer Nicolas Pitre <nico@cam.org> 1237165281 -0400

[ARM] make page_to_dma() highmem aware

If a machine class has a custom __virt_to_bus() implementation then it
must provide a __arch_page_to_dma() implementation as well which is
_not_ based on page_address() to support highmem.

This patch fixes existing __arch_page_to_dma() and provide a default
implementation otherwise.  The default implementation for highmem is
based on __pfn_to_bus() which is defined only when no custom
__virt_to_bus() is provided by the machine class.

That leaves only ebsa110 and footbridge which cannot support highmem
until they provide their own __arch_page_to_dma() implementation.
But highmem support on those legacy platforms with limited memory is
certainly not a priority.

Signed-off-by: Nicolas Pitre <nico@marvell.com>