x86: Add find_early_area_size

Prepare to move bck find_e820_area_size back to e820.c.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1265793639-15071-22-git-send-email-yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --git a/arch/x86/kernel/early_res.c b/arch/x86/kernel/early_res.c
index 1cf2c2f..bfa1ba7 100644 (file)
--- a/arch/x86/kernel/early_res.c
+++ b/arch/x86/kernel/early_res.c
@@ -476,6 +476,29 @@ out:
        return -1ULL;
 }
 
+u64 __init find_early_area_size(u64 ei_start, u64 ei_last, u64 start,
+                        u64 *sizep, u64 align)
+{
+       u64 addr, last;
+
+       addr = round_up(ei_start, align);
+       if (addr < start)
+               addr = round_up(start, align);
+       if (addr >= ei_last)
+               goto out;
+       *sizep = ei_last - addr;
+       while (bad_addr_size(&addr, sizep, align) && addr + *sizep <= ei_last)
+               ;
+       last = addr + *sizep;
+       if (last > ei_last)
+               goto out;
+
+       return addr;
+
+out:
+       return -1ULL;
+}
+
 /*
  * Find a free area with specified alignment in a specific range.
  */
@@ -513,24 +536,20 @@ u64 __init find_e820_area_size(u64 start, u64 *sizep, u64 align)
 
        for (i = 0; i < e820.nr_map; i++) {
                struct e820entry *ei = &e820.map[i];
-               u64 addr, last;
-               u64 ei_last;
+               u64 addr;
+               u64 ei_start, ei_last;
 
                if (ei->type != E820_RAM)
                        continue;
-               addr = round_up(ei->addr, align);
+
                ei_last = ei->addr + ei->size;
-               if (addr < start)
-                       addr = round_up(start, align);
-               if (addr >= ei_last)
-                       continue;
-               *sizep = ei_last - addr;
-               while (bad_addr_size(&addr, sizep, align) &&
-                       addr + *sizep <= ei_last)
-                       ;
-               last = addr + *sizep;
-               if (last > ei_last)
+               ei_start = ei->addr;
+               addr = find_early_area_size(ei_start, ei_last, start,
+                                        sizep, align);
+
+               if (addr == -1ULL)
                        continue;
+
                return addr;
        }