mlx4_core: maintain available field in bitmap allocator

Add mlx4_bitmap_avail() to give the number of available resources. We want to
use this as a hint to whether to allocate a resources or not. This patch is
introduced to be used with allocation blue flame registers.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 15 insertions, 0 deletions

diff --git a/drivers/net/mlx4/alloc.c b/drivers/net/mlx4/alloc.c
index 3a4277f6fac4..116cae334dad 100644
--- a/drivers/net/mlx4/alloc.c
+++ b/drivers/net/mlx4/alloc.c
@@ -62,6 +62,9 @@ u32 mlx4_bitmap_alloc(struct mlx4_bitmap *bitmap)
         } else
                 obj = -1;
 
+        if (obj != -1)
+                --bitmap->avail;
+
         spin_unlock(&bitmap->lock);
 
         return obj;
@@ -101,11 +104,19 @@ u32 mlx4_bitmap_alloc_range(struct mlx4_bitmap *bitmap, int cnt, int align)
         } else
                 obj = -1;
 
+        if (obj != -1)
+                bitmap->avail -= cnt;
+
         spin_unlock(&bitmap->lock);
 
         return obj;
 }
 
+u32 mlx4_bitmap_avail(struct mlx4_bitmap *bitmap)
+{
+        return bitmap->avail;
+}
+
 void mlx4_bitmap_free_range(struct mlx4_bitmap *bitmap, u32 obj, int cnt)
 {
         obj &= bitmap->max + bitmap->reserved_top - 1;
@@ -115,6 +126,7 @@ void mlx4_bitmap_free_range(struct mlx4_bitmap *bitmap, u32 obj, int cnt)
         bitmap->last = min(bitmap->last, obj);
         bitmap->top = (bitmap->top + bitmap->max + bitmap->reserved_top)
                         & bitmap->mask;
+        bitmap->avail += cnt;
         spin_unlock(&bitmap->lock);
 }
 
@@ -130,6 +142,7 @@ int mlx4_bitmap_init(struct mlx4_bitmap *bitmap, u32 num, u32 mask,
         bitmap->max  = num - reserved_top;
         bitmap->mask = mask;
         bitmap->reserved_top = reserved_top;
+        bitmap->avail = num - reserved_top - reserved_bot;
         spin_lock_init(&bitmap->lock);
         bitmap->table = kzalloc(BITS_TO_LONGS(bitmap->max) *
                                 sizeof (long), GFP_KERNEL);
diff --git a/drivers/net/mlx4/mlx4.h b/drivers/net/mlx4/mlx4.h
index bc9a21657a4f..c1e0e5f1bcdb 100644
--- a/drivers/net/mlx4/mlx4.h
+++ b/drivers/net/mlx4/mlx4.h
@@ -105,6 +105,7 @@ struct mlx4_bitmap {
         u32                     max;
         u32                     reserved_top;
         u32                     mask;
+        u32                     avail;
         spinlock_t              lock;
         unsigned long          *table;
 };
@@ -371,6 +372,7 @@ u32 mlx4_bitmap_alloc(struct mlx4_bitmap *bitmap);
 void mlx4_bitmap_free(struct mlx4_bitmap *bitmap, u32 obj);
 u32 mlx4_bitmap_alloc_range(struct mlx4_bitmap *bitmap, int cnt, int align);
 void mlx4_bitmap_free_range(struct mlx4_bitmap *bitmap, u32 obj, int cnt);
+u32 mlx4_bitmap_avail(struct mlx4_bitmap *bitmap);
 int mlx4_bitmap_init(struct mlx4_bitmap *bitmap, u32 num, u32 mask,
                      u32 reserved_bot, u32 resetrved_top);
 void mlx4_bitmap_cleanup(struct mlx4_bitmap *bitmap);