Anders Grafström reports that footbridge fails to build after 1c4a4f4.
Fix this by adding the necessary definitions for __pfn_to_bus and
__bus_to_pfn.
Reported-by: Anders Grafström <anders.grafstrom@netinsight.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Let's provide an overridable default instead of having every machine
class define __virt_to_bus and __bus_to_virt to the same thing. What
most platforms are using is bus_addr == phys_addr so such is the default.
One exception is ebsa110 which has no DMA what so ever, so the actual
definition is not important except only for proper compilation. Also
added a comment about the special footbridge bus translation.
Let's also remove comments alluding to set_dma_addr which is not
(and should not) be commonly used.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Russell King