x86, mm: Break down init_all_memory_mapping

Will replace that with top-down page table initialization.
New API need to take range: init_range_memory_mapping()

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-21-git-send-email-yinghai@kernel.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 19 insertions, 22 deletions

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index da591ebc8d12..c688ea3887f2 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -398,40 +398,30 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
  * Depending on the alignment of E820 ranges, this may possibly result in using
  * smaller size (i.e. 4K instead of 2M or 1G) page tables.
  */
-static void __init init_all_memory_mapping(void)
+static void __init init_range_memory_mapping(unsigned long range_start,
+                                           unsigned long range_end)
 {
         unsigned long start_pfn, end_pfn;
         int i;
 
-        /* the ISA range is always mapped regardless of memory holes */
-        init_memory_mapping(0, ISA_END_ADDRESS);
-
         for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
                 u64 start = (u64)start_pfn << PAGE_SHIFT;
                 u64 end = (u64)end_pfn << PAGE_SHIFT;
 
-                if (end <= ISA_END_ADDRESS)
+                if (end <= range_start)
                         continue;
 
-                if (start < ISA_END_ADDRESS)
-                        start = ISA_END_ADDRESS;
-#ifdef CONFIG_X86_32
-                /* on 32 bit, we only map up to max_low_pfn */
-                if ((start >> PAGE_SHIFT) >= max_low_pfn)
+                if (start < range_start)
+                        start = range_start;
+
+                if (start >= range_end)
                         continue;
 
-                if ((end >> PAGE_SHIFT) > max_low_pfn)
-                        end = max_low_pfn << PAGE_SHIFT;
-#endif
-                init_memory_mapping(start, end);
-        }
+                if (end > range_end)
+                        end = range_end;
 
-#ifdef CONFIG_X86_64
-        if (max_pfn > max_low_pfn) {
-                /* can we preseve max_low_pfn ?*/
-                max_low_pfn = max_pfn;
+                init_memory_mapping(start, end);
         }
-#endif
 }
 
 void __init init_mem_mapping(void)
@@ -461,8 +451,15 @@ void __init init_mem_mapping(void)
                 (pgt_buf_top << PAGE_SHIFT) - 1);
 
         max_pfn_mapped = 0; /* will get exact value next */
-        init_all_memory_mapping();
-
+        /* the ISA range is always mapped regardless of memory holes */
+        init_memory_mapping(0, ISA_END_ADDRESS);
+        init_range_memory_mapping(ISA_END_ADDRESS, end);
+#ifdef CONFIG_X86_64
+        if (max_pfn > max_low_pfn) {
+                /* can we preseve max_low_pfn ?*/
+                max_low_pfn = max_pfn;
+        }
+#endif
         /*
          * Reserve the kernel pagetable pages we used (pgt_buf_start -
          * pgt_buf_end) and free the other ones (pgt_buf_end - pgt_buf_top)