[MIPS] 64-bit Sibyte kernels need DMA32.

Sibyte SOCs only have 32-bit PCI.  Due to the sparse use of the address
space only the first 1GB of memory is mapped at physical addresses
below 1GB.  If a system has more than 1GB of memory 32-bit DMA will
not be able to reach all of it.

For now this patch is good enough to keep Sibyte users happy but it seems
eventually something like swiotlb will be needed for Sibyte.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 7750829b416a..4c6ba7b30a68 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -515,6 +515,7 @@ config SIBYTE_SWARM
         select SYS_SUPPORTS_HIGHMEM
         select SYS_SUPPORTS_KGDB
         select SYS_SUPPORTS_LITTLE_ENDIAN
+        select ZONE_DMA32 if 64BIT
 
 config SIBYTE_LITTLESUR
         bool "Sibyte BCM91250C2-LittleSur"
@@ -565,6 +566,7 @@ config SIBYTE_BIGSUR
         select SYS_SUPPORTS_BIG_ENDIAN
         select SYS_SUPPORTS_HIGHMEM
         select SYS_SUPPORTS_LITTLE_ENDIAN
+        select ZONE_DMA32 if 64BIT
 
 config SNI_RM
         bool "SNI RM200/300/400"
@@ -1664,6 +1666,9 @@ config ARCH_DISCONTIGMEM_ENABLE
           or have huge holes in the physical address space for other reasons.
           See <file:Documentation/vm/numa> for more.
 
+config ARCH_POPULATES_NODE_MAP
+        def_bool y
+
 config ARCH_SPARSEMEM_ENABLE
         bool
         select SPARSEMEM_STATIC
@@ -1969,6 +1974,9 @@ config I8253
 config PCSPEAKER
         bool
 
+config ZONE_DMA32
+        bool
+
 source "drivers/pcmcia/Kconfig"
 
 source "drivers/pci/hotplug/Kconfig"