[ARM] 5295/1: make ZONE_DMA optional

Most ARM machines don't need a special "DMA" memory zone, and
when configured out, the kernel becomes a bit smaller:

|   text    data     bss     dec     hex filename
|3826182  102384  111700 4040266  3da64a vmlinux
|3823593  101616  111700 4036909  3d992d vmlinux.nodmazone

This is because the system now has only one zone total which effect is
to optimize away many conditionals in page allocation paths.

So let's configure this zone only on machines that need split zones.

Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index f5bf38b5f38d..ea52fae33290 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -148,7 +148,6 @@ config ARCH_MAY_HAVE_PC_FDC
 
 config ZONE_DMA
         bool
-        default y
 
 config GENERIC_ISA_DMA
         bool
@@ -357,6 +356,7 @@ config ARCH_IXP4XX
         select GENERIC_GPIO
         select GENERIC_TIME
         select GENERIC_CLOCKEVENTS
+        select ZONE_DMA if PCI
         help
           Support for Intel's IXP4XX (XScale) family of processors.
 
@@ -503,6 +503,7 @@ config ARCH_SHARK
         bool "Shark"
         select ISA
         select ISA_DMA
+        select ZONE_DMA
         select PCI
         help
           Support for the StrongARM based Digital DNARD machine, also known
@@ -524,6 +525,7 @@ config ARCH_DAVINCI
         select GENERIC_CLOCKEVENTS
         select GENERIC_GPIO
         select HAVE_CLK
+        select ZONE_DMA
         help
           Support for TI's DaVinci platform.