powerpc: Dynamic DMA zone limits

Platform code can call limit_zone_pfn() to set appropriate limits
for ZONE_DMA and ZONE_DMA32, and dma_direct_alloc_coherent() will
select a suitable zone based on a device's mask and the pfn limits that
platform code has configured.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: Shaohui Xie <Shaohui.Xie@freescale.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index bd6dd6ed3a9f..d003409b5f98 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -285,6 +285,10 @@ config PPC_EMULATE_SSTEP
         bool
         default y if KPROBES || UPROBES || XMON || HAVE_HW_BREAKPOINT
 
+config ZONE_DMA32
+        bool
+        default y if PPC64
+
 source "init/Kconfig"
 
 source "kernel/Kconfig.freezer"