x86, mm: Trim memory in memblock to be page aligned

We will not map partial pages, so need to make sure memblock
allocation will not allocate those bytes out.

Also we will use for_each_mem_pfn_range() to loop to map memory
range to keep them consistent.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/CAE9FiQVZirvaBMFYRfXMmWEcHbKSicQEHz4VAwUv0xFCk51ZNw@mail.gmail.com
Acked-by: Jacob Shin <jacob.shin@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index ed858e9e9a7461aa9b4f8aa42a52c79d57d84507..df06ade26bef8485af1a66d797370385d0012e52 100644 (file)
--- 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 569d67d4243ed99c4b896fac81442531b9d05cbc..d452ee191066456278080c92322e093986baa1fb 100644 (file)
--- 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 931eef145af5eed370ed6f2b0c9dc577295be6ff..625905523c2a1592f539c46f6721723d62376648 100644 (file)
--- 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)
 {