[ARM] remove a common set of __virt_to_bus definitions

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>

1 files changed, 1 insertions, 8 deletions

diff --git a/arch/arm/mach-integrator/include/mach/memory.h b/arch/arm/mach-integrator/include/mach/memory.h
index be7e63c21d2..30d41d0e7d0 100644
--- a/arch/arm/mach-integrator/include/mach/memory.h
+++ b/arch/arm/mach-integrator/include/mach/memory.h
@@ -24,15 +24,8 @@
  * Physical DRAM offset.
  */
 #define PHYS_OFFSET     UL(0x00000000)
-#define BUS_OFFSET      UL(0x80000000)
 
-/*
- * Virtual view <-> DMA view memory address translations
- * virt_to_bus: Used to translate the virtual address to an
- *              address suitable to be passed to set_dma_addr
- * bus_to_virt: Used to convert an address for DMA operations
- *              to an address that the kernel can use.
- */
+#define BUS_OFFSET      UL(0x80000000)
 #define __virt_to_bus(x)        (x - PAGE_OFFSET + BUS_OFFSET)
 #define __bus_to_virt(x)        (x - BUS_OFFSET + PAGE_OFFSET)