ARM: ensure membank array is always sorted

This was missing from the noMMU code, so there was the possibility
of things not working as expected if out of order memory information
was passed.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 7fd9b5eb177..759878355a0 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -18,6 +18,7 @@
 #include <linux/highmem.h>
 #include <linux/gfp.h>
 #include <linux/memblock.h>
+#include <linux/sort.h>
 
 #include <asm/mach-types.h>
 #include <asm/sections.h>
@@ -256,10 +257,19 @@ static void arm_memory_present(void)
 }
 #endif
 
+static int __init meminfo_cmp(const void *_a, const void *_b)
+{
+	const struct membank *a = _a, *b = _b;
+	long cmp = bank_pfn_start(a) - bank_pfn_start(b);
+	return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
+}
+
 void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
 {
 	int i;
 
+	sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL);
+
 	memblock_init();
 	for (i = 0; i < mi->nr_banks; i++)
 		memblock_add(mi->bank[i].start, mi->bank[i].size);