wii: use both mem1 and mem2 as ram

The Nintendo Wii video game console has two discontiguous RAM regions:
- MEM1: 24MB @ 0x00000000
- MEM2: 64MB @ 0x10000000

Unfortunately, the kernel currently does not support discontiguous RAM
memory regions on 32-bit PowerPC platforms.

This patch adds a series of workarounds to allow the use of the second
memory region (MEM2) as RAM by the kernel.
Basically, a single range of memory from the beginning of MEM1 to the
end of MEM2 is reported to the kernel, and a memory reservation is
created for the hole between MEM1 and MEM2.

With this patch the system is able to use all the available RAM and not
just ~27% of it.

This will no longer be needed when proper discontig memory support
for 32-bit PowerPC is added to the kernel.

Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/powerpc/mm/ppc_mmu_32.c b/arch/powerpc/mm/ppc_mmu_32.c
index 2d2a87e1015..f11c2cdcb0f 100644
--- a/arch/powerpc/mm/ppc_mmu_32.c
+++ b/arch/powerpc/mm/ppc_mmu_32.c
@@ -72,7 +72,7 @@ unsigned long p_mapped_by_bats(phys_addr_t pa)
 	return 0;
 }
 
-unsigned long __init mmu_mapin_ram(void)
+unsigned long __init mmu_mapin_ram(unsigned long top)
 {
 	unsigned long tot, bl, done;
 	unsigned long max_size = (256<<20);
@@ -86,7 +86,7 @@ unsigned long __init mmu_mapin_ram(void)
 
 	/* Make sure we don't map a block larger than the
 	   smallest alignment of the physical address. */
-	tot = total_lowmem;
+	tot = top;
 	for (bl = 128<<10; bl < max_size; bl <<= 1) {
 		if (bl * 2 > tot)
 			break;