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, 4 insertions, 0 deletions

diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
index 9ddcfb4dc13..703c7c2e0d9 100644
--- a/arch/powerpc/mm/init_32.c
+++ b/arch/powerpc/mm/init_32.c
@@ -131,9 +131,13 @@ void __init MMU_init(void)
 	MMU_setup();
 
 	if (lmb.memory.cnt > 1) {
+#ifndef CONFIG_WII
 		lmb.memory.cnt = 1;
 		lmb_analyze();
 		printk(KERN_WARNING "Only using first contiguous memory region");
+#else
+		wii_memory_fixups();
+#endif
 	}
 
 	total_lowmem = total_memory = lmb_end_of_DRAM() - memstart_addr;