x86: split out common code into find_overlapped_early()

This patch clean up reserve_early() family functions by extracting the
common part of reserve_early(), free_early() and bad_addr() into
find_overlapped_early().

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: andi@firstfloor.org
Cc: mingo@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 5d33b9c..ac5e9eb 100644 (file)
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -558,20 +558,34 @@ static struct early_res early_res[MAX_EARLY_RES] __initdata = {
        {}
 };
 
-void __init reserve_early(u64 start, u64 end, char *name)
+static int __init find_overlapped_early(u64 start, u64 end)
 {
        int i;
        struct early_res *r;
+
        for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
                r = &early_res[i];
                if (end > r->start && start < r->end)
-                       panic("Overlapping early reservations %llx-%llx %s to %llx-%llx %s\n",
-                             start, end - 1, name?name:"", r->start,
-                             r->end - 1, r->name);
+                       break;
        }
+
+       return i;
+}
+
+void __init reserve_early(u64 start, u64 end, char *name)
+{
+       int i;
+       struct early_res *r;
+
+       i = find_overlapped_early(start, end);
        if (i >= MAX_EARLY_RES)
                panic("Too many early reservations");
        r = &early_res[i];
+       if (r->end)
+               panic("Overlapping early reservations "
+                     "%llx-%llx %s to %llx-%llx %s\n",
+                     start, end - 1, name?name:"", r->start,
+                     r->end - 1, r->name);
        r->start = start;
        r->end = end;
        if (name)
@@ -583,14 +597,11 @@ void __init free_early(u64 start, u64 end)
        struct early_res *r;
        int i, j;
 
-       for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
-               r = &early_res[i];
-               if (start == r->start && end == r->end)
-                       break;
-       }
-       if (i >= MAX_EARLY_RES || !early_res[i].end)
+       i = find_overlapped_early(start, end);
+       r = &early_res[i];
+       if (i >= MAX_EARLY_RES || r->end != end || r->start != start)
                panic("free_early on not reserved area: %llx-%llx!",
-                        start, end);
+                        start, end - 1);
 
        for (j = i + 1; j < MAX_EARLY_RES && early_res[j].end; j++)
                ;
@@ -626,17 +637,16 @@ void __init early_res_to_bootmem(u64 start, u64 end)
 static inline int __init bad_addr(u64 *addrp, u64 size, u64 align)
 {
        int i;
-       u64 addr = *addrp, last;
+       u64 addr = *addrp;
        int changed = 0;
+       struct early_res *r;
 again:
-       last = addr + size;
-       for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
-               struct early_res *r = &early_res[i];
-               if (last >= r->start && addr < r->end) {
-                       *addrp = addr = round_up(r->end, align);
-                       changed = 1;
-                       goto again;
-               }
+       i = find_overlapped_early(addr, addr + size);
+       r = &early_res[i];
+       if (i < MAX_EARLY_RES && r->end) {
+               *addrp = addr = round_up(r->end, align);
+               changed = 1;
+               goto again;
        }
        return changed;
 }