mlx4_core: Move kernel doorbell management into core

In addition to mlx4_ib, there will be ethernet and FC consumers of
mlx4_core, so move the code for managing kernel doorbells into the
core module to avoid having to duplicate this multiple times.

Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
index ff7df1a..0a47457 100644
--- a/include/linux/mlx4/device.h
+++ b/include/linux/mlx4/device.h
@@ -208,6 +208,32 @@
 	int			page_shift;
 };
 
+enum {
+	MLX4_DB_PER_PAGE = PAGE_SIZE / 4
+};
+
+struct mlx4_db_pgdir {
+	struct list_head	list;
+	DECLARE_BITMAP(order0, MLX4_DB_PER_PAGE);
+	DECLARE_BITMAP(order1, MLX4_DB_PER_PAGE / 2);
+	unsigned long	       *bits[2];
+	__be32		       *db_page;
+	dma_addr_t		db_dma;
+};
+
+struct mlx4_ib_user_db_page;
+
+struct mlx4_db {
+	__be32			*db;
+	union {
+		struct mlx4_db_pgdir		*pgdir;
+		struct mlx4_ib_user_db_page	*user_page;
+	}			u;
+	dma_addr_t		dma;
+	int			index;
+	int			order;
+};
+
 struct mlx4_mr {
 	struct mlx4_mtt		mtt;
 	u64			iova;
@@ -341,6 +367,9 @@
 int mlx4_buf_write_mtt(struct mlx4_dev *dev, struct mlx4_mtt *mtt,
 		       struct mlx4_buf *buf);
 
+int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, int order);
+void mlx4_db_free(struct mlx4_dev *dev, struct mlx4_db *db);
+
 int mlx4_cq_alloc(struct mlx4_dev *dev, int nent, struct mlx4_mtt *mtt,
 		  struct mlx4_uar *uar, u64 db_rec, struct mlx4_cq *cq);
 void mlx4_cq_free(struct mlx4_dev *dev, struct mlx4_cq *cq);