3 files changed, 28 insertions, 0 deletions

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index ed858e9e9a74..df06ade26bef 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1077,6 +1077,9 @@ void __init memblock_x86_fill(void)
                 memblock_add(ei->addr, ei->size);
         }
 
+        /* throw away partial pages */
+        memblock_trim_memory(PAGE_SIZE);
+
         memblock_dump_all();
 }
 
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 569d67d4243e..d452ee191066 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -57,6 +57,7 @@ int memblock_add(phys_addr_t base, phys_addr_t size);
 int memblock_remove(phys_addr_t base, phys_addr_t size);
 int memblock_free(phys_addr_t base, phys_addr_t size);
 int memblock_reserve(phys_addr_t base, phys_addr_t size);
+void memblock_trim_memory(phys_addr_t align);
 
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn,
diff --git a/mm/memblock.c b/mm/memblock.c
index 931eef145af5..625905523c2a 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -930,6 +930,30 @@ int __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t si
         return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
 }
 
+void __init_memblock memblock_trim_memory(phys_addr_t align)
+{
+        int i;
+        phys_addr_t start, end, orig_start, orig_end;
+        struct memblock_type *mem = &memblock.memory;
+
+        for (i = 0; i < mem->cnt; i++) {
+                orig_start = mem->regions[i].base;
+                orig_end = mem->regions[i].base + mem->regions[i].size;
+                start = round_up(orig_start, align);
+                end = round_down(orig_end, align);
+
+                if (start == orig_start && end == orig_end)
+                        continue;
+
+                if (start < end) {
+                        mem->regions[i].base = start;
+                        mem->regions[i].size = end - start;
+                } else {
+                        memblock_remove_region(mem, i);
+                        i--;
+                }
+        }
+}
 
 void __init_memblock memblock_set_current_limit(phys_addr_t limit)
 {