powerpc: Cleanup memblock usage

* early_init_devtree(): Total memory size is aligned to PAGE_SIZE;
  however, alignment isn't enforced if memory_limit is explicitly
  specified.  Simplify the logic and always apply PAGE_SIZE alignment.

* MMU_init(): memblock regions is truncated by directly modifying
  memblock.memory.cnt.  This is incomplete (reserved array is not
  truncated) and unnecessarily low level hindering further memblock
  improvments.  Use memblock_enforce_memory_limit() instead.

* wii_memory_fixups(): Unnecessarily low level direct manipulation of
  memblock regions.  The same result can be achieved using properly
  abstracted operations.  Reimplement using memblock API.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Yinghai Lu <yinghai@kernel.org>

1 files changed, 6 insertions, 11 deletions

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index a7ee83e6eb17..28500d4f29d9 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -754,17 +754,12 @@ void __init early_init_devtree(void *params)
 	early_reserve_mem();
 	phyp_dump_reserve_mem();
 
-	limit = memory_limit;
-	if (! limit) {
-		phys_addr_t memsize;
-
-		/* Ensure that total memory size is page-aligned, because
-		 * otherwise mark_bootmem() gets upset. */
-		memblock_analyze();
-		memsize = memblock_phys_mem_size();
-		if ((memsize & PAGE_MASK) != memsize)
-			limit = memsize & PAGE_MASK;
-	}
+	/*
+	 * Ensure that total memory size is page-aligned, because otherwise
+	 * mark_bootmem() gets upset.
+	 */
+	memblock_analyze();
+	limit = ALIGN(memory_limit ?: memblock_phys_mem_size(), PAGE_SIZE);
 	memblock_enforce_memory_limit(limit);
 
 	memblock_analyze();