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

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>

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 19dc455b4f3dd072d0e58abdfed2de6f8ae5727c..c948c440ea2c8758020c33718dac66c5d3ff363f 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 82aa349d2f7a040b489bee441bf848b61119f788..0e490e8dcebae360c8c11ab727b6d85eaf61490e 100644 (file)
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -929,6 +929,30 @@ 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)
 {