mlx5_core: Add support for page faults events and low level handling

* Add a handler function pointer in the mlx5_core_qp struct for page
  fault events. Handle page fault events by calling the handler
  function, if not NULL.
* Add on-demand paging capability query command.
* Export command for resuming QPs after page faults.
* Add various constants related to paging support.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index b1bf415..7088dcd 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -113,6 +113,13 @@
 	MLX5_REG_HOST_ENDIANNESS = 0x7004,
 };
 
+enum mlx5_page_fault_resume_flags {
+	MLX5_PAGE_FAULT_RESUME_REQUESTOR = 1 << 0,
+	MLX5_PAGE_FAULT_RESUME_WRITE	 = 1 << 1,
+	MLX5_PAGE_FAULT_RESUME_RDMA	 = 1 << 2,
+	MLX5_PAGE_FAULT_RESUME_ERROR	 = 1 << 7,
+};
+
 enum dbg_rsc_type {
 	MLX5_DBG_RSC_QP,
 	MLX5_DBG_RSC_EQ,
@@ -703,6 +710,9 @@
 void mlx5_fill_page_array(struct mlx5_buf *buf, __be64 *pas);
 void mlx5_cq_completion(struct mlx5_core_dev *dev, u32 cqn);
 void mlx5_rsc_event(struct mlx5_core_dev *dev, u32 rsn, int event_type);
+#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
+void mlx5_eq_pagefault(struct mlx5_core_dev *dev, struct mlx5_eqe *eqe);
+#endif
 void mlx5_srq_event(struct mlx5_core_dev *dev, u32 srqn, int event_type);
 struct mlx5_core_srq *mlx5_core_get_srq(struct mlx5_core_dev *dev, u32 srqn);
 void mlx5_cmd_comp_handler(struct mlx5_core_dev *dev, unsigned long vector);
@@ -740,6 +750,8 @@
 			 int npsvs, u32 *sig_index);
 int mlx5_core_destroy_psv(struct mlx5_core_dev *dev, int psv_num);
 void mlx5_core_put_rsc(struct mlx5_core_rsc_common *common);
+int mlx5_query_odp_caps(struct mlx5_core_dev *dev,
+			struct mlx5_odp_caps *odp_caps);
 
 static inline u32 mlx5_mkey_to_idx(u32 mkey)
 {