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>

1 files changed, 30 insertions, 20 deletions

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 5d33b9c08d1b..ac5e9ebf70ea 100644
--- 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;
 }