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>

1 files changed, 32 insertions, 13 deletions

diff --git a/arch/x86/kernel/early_res.c b/arch/x86/kernel/early_res.c
index 1cf2c2f9ea68..bfa1ba705d48 100644
--- 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;
         }