x86, mm: Trim memory in memblock to be page aligned
Yinghai Lu [Mon, 22 Oct 2012 23:35:18 +0000 (16:35 -0700)]
commit 6ede1fd3cb404c0016de6ac529df46d561bd558b upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/x86/kernel/e820.c
include/linux/memblock.h
mm/memblock.c

index 62d61e9..298dc00 100644 (file)
@@ -1076,6 +1076,9 @@ void __init memblock_x86_fill(void)
                memblock_add(ei->addr, ei->size);
        }
 
+       /* throw away partial pages */
+       memblock_trim_memory(PAGE_SIZE);
+
        memblock_dump_all();
 }
 
index 19dc455..c948c44 100644 (file)
@@ -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,
index 280d3d7..11e5bd1 100644 (file)
@@ -908,6 +908,30 @@ 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)
 {