[POWERPC] Make rheap safe for spinlocks

The rheap allocation function, rh_alloc, could call kmalloc with GFP_KERNEL.
This can sleep, which means you couldn't hold a spinlock while called rh_alloc.
Change all kmalloc calls to use GFP_ATOMIC so that it won't sleep. This is
safe because only small blocks are allocated.

Signed-off-by: Timur Tabi <[e-mail]>
Signed-off-by: Kumar Gala <[e-mail]>

arch/powerpc/lib/rheap.c

···
 
 	new_blocks = max_blocks - info->max_blocks;
 
-	block = kmalloc(sizeof(rh_block_t) * max_blocks, GFP_KERNEL);
+	block = kmalloc(sizeof(rh_block_t) * max_blocks, GFP_ATOMIC);
 	if (block == NULL)
 		return -ENOMEM;
 
···
 	if ((alignment & (alignment - 1)) != 0)
 		return ERR_PTR(-EINVAL);
 
-	info = kmalloc(sizeof(*info), GFP_KERNEL);
+	info = kmalloc(sizeof(*info), GFP_ATOMIC);
 	if (info == NULL)
 		return ERR_PTR(-ENOMEM);