powerpc: allow ioremap within reserved memory regions

Add a flag to let a platform ioremap memory regions marked as reserved.

This flag will be used later by the Nintendo Wii support code to allow
ioremapping the I/O region sitting between MEM1 and MEM2 and marked
as reserved RAM in the patch "wii: use both mem1 and mem2 as ram".

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, 5 insertions, 0 deletions

diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
index 703c7c2e0d9f..4ec900af332f 100644
--- a/arch/powerpc/mm/init_32.c
+++ b/arch/powerpc/mm/init_32.c
@@ -82,6 +82,11 @@ extern struct task_struct *current_set[NR_CPUS];
 int __map_without_bats;
 int __map_without_ltlbs;
 
+/*
+ * This tells the system to allow ioremapping memory marked as reserved.
+ */
+int __allow_ioremap_reserved;
+
 /* max amount of low RAM to map in */
 unsigned long __max_low_memory = MAX_LOW_MEM;