powerpc: use mm zones more sensibly
Powerpc has somewhat odd usage where ZONE_DMA is used for all memory on
common 64-bit configfs, and ZONE_DMA32 is used for 31-bit schemes.
Move to a scheme closer to what other architectures use (and I dare to
say the intent of the system):
- ZONE_DMA: optionally for memory < 31-bit (64-bit embedded only)
- ZONE_NORMAL: everything addressable by the kernel
- ZONE_HIGHMEM: memory > 32-bit for 32-bit kernels
Also provide information on how ZONE_DMA is used by defining
ARCH_ZONE_DMA_BITS.
Contains various fixes from Benjamin Herrenschmidt.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 847705a..e2d01cc 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -314,7 +314,7 @@ enum zone_type {
* Architecture Limit
* ---------------------------
* parisc, ia64, sparc <4G
- * s390 <2G
+ * s390, powerpc <2G
* arm Various
* alpha Unlimited or 0-16MB.
*