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 ed858e9..df06ade 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 569d67d..d452ee1 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 931eef1..6259055 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)
 {