mlx4_core: Add QP range reservation support

[linux-2.6-block.git] / drivers / net / mlx4 / alloc.c

diff --git a/drivers/net/mlx4/alloc.c b/drivers/net/mlx4/alloc.c
index f9d6b4dca180e49f6d16fc4ebfe594831cc0cf29..e6c0d5bb5dcb68b897e4e3f6d640d2fc1f69e6e3 100644 (file)
--- a/drivers/net/mlx4/alloc.c
+++ b/drivers/net/mlx4/alloc.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2006, 2007 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2007, 2008 Mellanox Technologies. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -64,10 +65,82 @@ u32 mlx4_bitmap_alloc(struct mlx4_bitmap *bitmap)
 
 void mlx4_bitmap_free(struct mlx4_bitmap *bitmap, u32 obj)
 {
+       mlx4_bitmap_free_range(bitmap, obj, 1);
+}
+
+static unsigned long find_aligned_range(unsigned long *bitmap,
+                                       u32 start, u32 nbits,
+                                       int len, int align)
+{
+       unsigned long end, i;
+
+again:
+       start = ALIGN(start, align);
+
+       while ((start < nbits) && test_bit(start, bitmap))
+               start += align;
+
+       if (start >= nbits)
+               return -1;
+
+       end = start+len;
+       if (end > nbits)
+               return -1;
+
+       for (i = start + 1; i < end; i++) {
+               if (test_bit(i, bitmap)) {
+                       start = i + 1;
+                       goto again;
+               }
+       }
+
+       return start;
+}
+
+u32 mlx4_bitmap_alloc_range(struct mlx4_bitmap *bitmap, int cnt, int align)
+{
+       u32 obj, i;
+
+       if (likely(cnt == 1 && align == 1))
+               return mlx4_bitmap_alloc(bitmap);
+
+       spin_lock(&bitmap->lock);
+
+       obj = find_aligned_range(bitmap->table, bitmap->last,
+                                bitmap->max, cnt, align);
+       if (obj >= bitmap->max) {
+               bitmap->top = (bitmap->top + bitmap->max) & bitmap->mask;
+               obj = find_aligned_range(bitmap->table, 0,
+                                        bitmap->max,
+                                        cnt, align);
+       }
+
+       if (obj < bitmap->max) {
+               for (i = 0; i < cnt; i++)
+                       set_bit(obj + i, bitmap->table);
+               if (obj == bitmap->last) {
+                       bitmap->last = (obj + cnt);
+                       if (bitmap->last >= bitmap->max)
+                               bitmap->last = 0;
+               }
+               obj |= bitmap->top;
+       } else
+               obj = -1;
+
+       spin_unlock(&bitmap->lock);
+
+       return obj;
+}
+
+void mlx4_bitmap_free_range(struct mlx4_bitmap *bitmap, u32 obj, int cnt)
+{
+       u32 i;
+
        obj &= bitmap->max - 1;
 
        spin_lock(&bitmap->lock);
-       clear_bit(obj, bitmap->table);
+       for (i = 0; i < cnt; i++)
+               clear_bit(obj + i, bitmap->table);
        bitmap->last = min(bitmap->last, obj);
        bitmap->top = (bitmap->top + bitmap->max) & bitmap->mask;
        spin_unlock(&bitmap->lock);