1 files changed, 45 insertions, 7 deletions

diff --git a/arch/blackfin/kernel/setup.c b/arch/blackfin/kernel/setup.c
index 2255c289a71..a871d835824 100644
--- a/arch/blackfin/kernel/setup.c
+++ b/arch/blackfin/kernel/setup.c
@@ -547,11 +547,38 @@ static __init void  memory_setup(void)
                 );
 }
 
+/*
+ * Find the lowest, highest page frame number we have available
+ */
+void __init find_min_max_pfn(void)
+{
+        int i;
+
+        max_pfn = 0;
+        min_low_pfn = memory_end;
+
+        for (i = 0; i < bfin_memmap.nr_map; i++) {
+                unsigned long start, end;
+                /* RAM? */
+                if (bfin_memmap.map[i].type != BFIN_MEMMAP_RAM)
+                        continue;
+                start = PFN_UP(bfin_memmap.map[i].addr);
+                end = PFN_DOWN(bfin_memmap.map[i].addr +
+                                bfin_memmap.map[i].size);
+                if (start >= end)
+                        continue;
+                if (end > max_pfn)
+                        max_pfn = end;
+                if (start < min_low_pfn)
+                        min_low_pfn = start;
+        }
+}
+
 static __init void setup_bootmem_allocator(void)
 {
         int bootmap_size;
         int i;
-        unsigned long min_pfn, max_pfn;
+        unsigned long start_pfn, end_pfn;
         unsigned long curr_pfn, last_pfn, size;
 
         /* mark memory between memory_start and memory_end usable */
@@ -561,8 +588,19 @@ static __init void setup_bootmem_allocator(void)
         sanitize_memmap(bfin_memmap.map, &bfin_memmap.nr_map);
         print_memory_map("boot memmap");
 
-        min_pfn = PAGE_OFFSET >> PAGE_SHIFT;
-        max_pfn = memory_end >> PAGE_SHIFT;
+        /* intialize globals in linux/bootmem.h */
+        find_min_max_pfn();
+        /* pfn of the last usable page frame */
+        if (max_pfn > memory_end >> PAGE_SHIFT)
+                max_pfn = memory_end >> PAGE_SHIFT;
+        /* pfn of last page frame directly mapped by kernel */
+        max_low_pfn = max_pfn;
+        /* pfn of the first usable page frame after kernel image*/
+        if (min_low_pfn < memory_start >> PAGE_SHIFT)
+                min_low_pfn = memory_start >> PAGE_SHIFT;
+
+        start_pfn = PAGE_OFFSET >> PAGE_SHIFT;
+        end_pfn = memory_end >> PAGE_SHIFT;
 
         /*
          * give all the memory to the bootmap allocator,  tell it to put the
@@ -570,7 +608,7 @@ static __init void setup_bootmem_allocator(void)
          */
         bootmap_size = init_bootmem_node(NODE_DATA(0),
                         memory_start >> PAGE_SHIFT,     /* map goes here */
-                        min_pfn, max_pfn);
+                        start_pfn, end_pfn);
 
         /* register the memmap regions with the bootmem allocator */
         for (i = 0; i < bfin_memmap.nr_map; i++) {
@@ -583,7 +621,7 @@ static __init void setup_bootmem_allocator(void)
                  * We are rounding up the start address of usable memory:
                  */
                 curr_pfn = PFN_UP(bfin_memmap.map[i].addr);
-                if (curr_pfn >= max_pfn)
+                if (curr_pfn >= end_pfn)
                         continue;
                 /*
                  * ... and at the end of the usable range downwards:
@@ -591,8 +629,8 @@ static __init void setup_bootmem_allocator(void)
                 last_pfn = PFN_DOWN(bfin_memmap.map[i].addr +
                                          bfin_memmap.map[i].size);
 
-                if (last_pfn > max_pfn)
-                        last_pfn = max_pfn;
+                if (last_pfn > end_pfn)
+                        last_pfn = end_pfn;
 
                 /*
                  * .. finally, did all the rounding and playing