arm: mm: Don't free prohibited memmap entries

The VM subsystem assumes that there are valid memmap entries to
the bank end aligned to MAX_ORDER_NR_PAGES. It will try and read
these page structs, and so we cannot free any memmap entries that
it may inspect.

Signed-off-by: Michael Bohan <mbohan@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>

1 files changed, 9 insertions, 10 deletions

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index f6a999465323..e18c7cedb482 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -495,28 +495,27 @@ static void __init free_unused_memmap_node(int node, struct meminfo *mi)
         unsigned int i;
 
         /*
-         * [FIXME] This relies on each bank being in address order.  This
-         * may not be the case, especially if the user has provided the
-         * information on the command line.
+         * This relies on each bank being in address order.
+         * The banks are sorted previously in bootmem_init().
          */
         for_each_nodebank(i, mi, node) {
                 struct membank *bank = &mi->bank[i];
 
                 bank_start = bank_pfn_start(bank);
-                if (bank_start < prev_bank_end) {
-                        printk(KERN_ERR "MEM: unordered memory banks.  "
-                                "Not freeing memmap.\n");
-                        break;
-                }
 
                 /*
                  * If we had a previous bank, and there is a space
                  * between the current bank and the previous, free it.
                  */
-                if (prev_bank_end && prev_bank_end != bank_start)
+                if (prev_bank_end && prev_bank_end < bank_start)
                         free_memmap(node, prev_bank_end, bank_start);
 
-                prev_bank_end = bank_pfn_end(bank);
+                /*
+                 * Align up here since the VM subsystem insists that the
+                 * memmap entries are valid from the bank end aligned to
+                 * MAX_ORDER_NR_PAGES.
+                 */
+                prev_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES);
         }
 }