x86, mm: Separate out calculate_table_space_size()

It should take physical address range that will need to be mapped.
find_early_table_space should take range that pgt buff should be in.

Separating page table size calculating and finding early page table to
reduce confusing.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-9-git-send-email-yinghai@kernel.org
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 27 insertions, 11 deletions

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 1ce0d033fafc..7b961d0b1389 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -196,12 +196,10 @@ static int __meminit split_mem_range(struct map_range *mr, int nr_range,
  * mr[0].start to mr[nr_range - 1].end, while accounting for possible 2M and 1GB
  * pages. Then find enough contiguous space for those page tables.
  */
-static void __init find_early_table_space(unsigned long start, unsigned long end)
+static unsigned long __init calculate_table_space_size(unsigned long start, unsigned long end)
 {
         int i;
         unsigned long puds = 0, pmds = 0, ptes = 0, tables;
-        unsigned long good_end;
-        phys_addr_t base;
         struct map_range mr[NR_RANGE_MR];
         int nr_range;
 
@@ -240,9 +238,17 @@ static void __init find_early_table_space(unsigned long start, unsigned long end
 #ifdef CONFIG_X86_32
         /* for fixmap */
         tables += roundup(__end_of_fixed_addresses * sizeof(pte_t), PAGE_SIZE);
-        good_end = max_pfn_mapped << PAGE_SHIFT;
 #endif
 
+        return tables;
+}
+
+static void __init find_early_table_space(unsigned long start,
+                                          unsigned long good_end,
+                                          unsigned long tables)
+{
+        phys_addr_t base;
+
         base = memblock_find_in_range(start, good_end, tables, PAGE_SIZE);
         if (!base)
                 panic("Cannot find space for the kernel page tables");
@@ -250,10 +256,6 @@ static void __init find_early_table_space(unsigned long start, unsigned long end
         pgt_buf_start = base >> PAGE_SHIFT;
         pgt_buf_end = pgt_buf_start;
         pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT);
-
-        printk(KERN_DEBUG "kernel direct mapping tables up to %#lx @ [mem %#010lx-%#010lx]\n",
-                mr[nr_range - 1].end - 1, pgt_buf_start << PAGE_SHIFT,
-                (pgt_buf_top << PAGE_SHIFT) - 1);
 }
 
 /*
@@ -291,6 +293,8 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
 
 void __init init_mem_mapping(void)
 {
+        unsigned long tables, good_end, end;
+
         probe_page_size_mask();
 
         /*
@@ -301,10 +305,18 @@ void __init init_mem_mapping(void)
          * nodes are discovered.
          */
 #ifdef CONFIG_X86_64
-        find_early_table_space(0, max_pfn<<PAGE_SHIFT);
+        end = max_pfn << PAGE_SHIFT;
+        good_end = end;
 #else
-        find_early_table_space(0, max_low_pfn<<PAGE_SHIFT);
+        end = max_low_pfn << PAGE_SHIFT;
+        good_end = max_pfn_mapped << PAGE_SHIFT;
 #endif
+        tables = calculate_table_space_size(0, end);
+        find_early_table_space(0, good_end, tables);
+        printk(KERN_DEBUG "kernel direct mapping tables up to %#lx @ [mem %#010lx-%#010lx] prealloc\n",
+                end - 1, pgt_buf_start << PAGE_SHIFT,
+                (pgt_buf_top << PAGE_SHIFT) - 1);
+
         max_low_pfn_mapped = init_memory_mapping(0, max_low_pfn<<PAGE_SHIFT);
         max_pfn_mapped = max_low_pfn_mapped;
 
@@ -331,9 +343,13 @@ void __init init_mem_mapping(void)
          * RO all the pagetable pages, including the ones that are beyond
          * pgt_buf_end at that time.
          */
-        if (pgt_buf_end > pgt_buf_start)
+        if (pgt_buf_end > pgt_buf_start) {
+                printk(KERN_DEBUG "kernel direct mapping tables up to %#lx @ [mem %#010lx-%#010lx] final\n",
+                        end - 1, pgt_buf_start << PAGE_SHIFT,
+                        (pgt_buf_end << PAGE_SHIFT) - 1);
                 x86_init.mapping.pagetable_reserve(PFN_PHYS(pgt_buf_start),
                                 PFN_PHYS(pgt_buf_end));
+        }
 
         /* stop the wrong using */
         pgt_buf_top = 0;