RDMA/qedr: Add doorbell overflow recovery support

Use the doorbell recovery mechanism to register rdma related doorbells
that will be restored in case there is a doorbell overflow attention.

Link: https://lore.kernel.org/r/20191030094417.16866-8-michal.kalderon@marvell.comSigned-off-by: Ariel Elior <ariel.elior@marvell.com>
Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/qedr/qedr.h

@@ -235,6 +235,7 @@ struct qedr_ucontext {
 	u64 dpi_phys_addr;
 	u32 dpi_size;
 	u16 dpi;
+	bool db_rec;
 };
 
 union db_prod64 {
@@ -262,6 +263,11 @@ struct qedr_userq {
 	struct qedr_pbl *pbl_tbl;
 	u64 buf_addr;
 	size_t buf_len;
+
+	/* doorbell recovery */
+	void __iomem *db_addr;
+	struct qedr_user_db_rec *db_rec_data;
+	struct rdma_user_mmap_entry *db_mmap_entry;
 };
 
 struct qedr_cq {
@@ -482,7 +488,10 @@ struct qedr_mr {
 struct qedr_user_mmap_entry {
 	struct rdma_user_mmap_entry rdma_entry;
 	struct qedr_dev *dev;
-	u64 io_address;
+	union {
+		u64 io_address;
+		void *address;
+	};
 	size_t length;
 	u16 dpi;
 	u8 mmap_flag;

include/uapi/rdma/qedr-abi.h

@@ -38,6 +38,15 @@
 #define QEDR_ABI_VERSION		(8)
 
 /* user kernel communication data structures. */
+enum qedr_alloc_ucontext_flags {
+	QEDR_ALLOC_UCTX_RESERVED	= 1 << 0,
+	QEDR_ALLOC_UCTX_DB_REC		= 1 << 1
+};
+
+struct qedr_alloc_ucontext_req {
+	__u32 context_flags;
+	__u32 reserved;
+};
 
 struct qedr_alloc_ucontext_resp {
 	__aligned_u64 db_pa;
@@ -74,6 +83,7 @@ struct qedr_create_cq_uresp {
 	__u32 db_offset;
 	__u16 icid;
 	__u16 reserved;
+	__aligned_u64 db_rec_addr;
 };
 
 struct qedr_create_qp_ureq {
@@ -109,6 +119,13 @@ struct qedr_create_qp_uresp {
 
 	__u32 rq_db2_offset;
 	__u32 reserved;
+
+	/* address of SQ doorbell recovery user entry */
+	__aligned_u64 sq_db_rec_addr;
+
+	/* address of RQ doorbell recovery user entry */
+	__aligned_u64 rq_db_rec_addr;
+
 };
 
 struct qedr_create_srq_ureq {
@@ -128,4 +145,12 @@ struct qedr_create_srq_uresp {
 	__u32 reserved1;
 };
 
+/* doorbell recovery entry allocated and populated by userspace doorbelling
+ * entities and mapped to kernel. Kernel uses this to register doorbell
+ * information with doorbell drop recovery mechanism.
+ */
+struct qedr_user_db_rec {
+	__aligned_u64 db_data; /* doorbell data */
+};
+
 #endif /* __QEDR_USER_H__ */