[POWERPC] Remove and replace uses of PPC_MEMSTART with memstart_addr

A number of users of PPC_MEMSTART (40x, ppc_mmu_32) can just always
use 0 as we don't support booting these kernels at non-zero physical
addresses since their exception vectors must be at 0 (or 0xfffx_xxxx).

For the sub-arches that support relocatable interrupt vectors
(book-e), it's reasonable to have memory start at a non-zero physical
address.  For those cases use the variable memstart_addr instead of
the #define PPC_MEMSTART since the only uses of PPC_MEMSTART are for
initialization and in the future we can set memstart_addr at runtime
to have a relocatable kernel.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 3 insertions, 4 deletions

diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
index 0c66a9f..1d7e5b8 100644
--- a/arch/powerpc/mm/init_32.c
+++ b/arch/powerpc/mm/init_32.c
@@ -59,8 +59,8 @@ DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
 unsigned long total_memory;
 unsigned long total_lowmem;
 
-unsigned long ppc_memstart;
-unsigned long ppc_memoffset = PAGE_OFFSET;
+phys_addr_t memstart_addr;
+phys_addr_t lowmem_end_addr;
 
 int boot_mapsize;
 #ifdef CONFIG_PPC_PMAC
@@ -145,8 +145,7 @@ void __init MMU_init(void)
 		printk(KERN_WARNING "Only using first contiguous memory region");
 	}
 
-	total_memory = lmb_end_of_DRAM();
-	total_lowmem = total_memory;
+	total_lowmem = total_memory = lmb_end_of_DRAM() - memstart_addr;
 
 #ifdef CONFIG_FSL_BOOKE
 	/* Freescale Book-E parts expect lowmem to be mapped by fixed TLB