IB/core: Introduce new fast registration API

The new fast registration  verb ib_map_mr_sg receives a scatterlist
and converts it to a page list under the verbs API thus hiding
the specific HW mapping details away from the consumer.

The provider drivers are provided with a generic helper ib_sg_to_pages
that converts a scatterlist into a vector of page addresses. The
drivers can still perform any HW specific page address setting
by passing a set_page function pointer which will be invoked for
each page address. This allows drivers to avoid keeping a shadow
page vectors and convert them to HW specific translations by doing
extra copies.

This API will allow ULPs to remove the duplicated code of constructing
a page vector from a given sg list.

The send work request ib_reg_wr also shrinks as it will contain only
mr, key and access flags in addition.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 85103af..065d37c 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -738,6 +738,7 @@ enum ib_wc_opcode {
 	IB_WC_LSO,
 	IB_WC_LOCAL_INV,
 	IB_WC_FAST_REG_MR,
+	IB_WC_REG_MR,
 	IB_WC_MASKED_COMP_SWAP,
 	IB_WC_MASKED_FETCH_ADD,
 /*
@@ -1025,6 +1026,7 @@ enum ib_wr_opcode {
 	IB_WR_RDMA_READ_WITH_INV,
 	IB_WR_LOCAL_INV,
 	IB_WR_FAST_REG_MR,
+	IB_WR_REG_MR,
 	IB_WR_MASKED_ATOMIC_CMP_AND_SWP,
 	IB_WR_MASKED_ATOMIC_FETCH_AND_ADD,
 	IB_WR_BIND_MW,
@@ -1157,6 +1159,18 @@ static inline struct ib_fast_reg_wr *fast_reg_wr(struct ib_send_wr *wr)
 	return container_of(wr, struct ib_fast_reg_wr, wr);
 }
 
+struct ib_reg_wr {
+	struct ib_send_wr	wr;
+	struct ib_mr		*mr;
+	u32			key;
+	int			access;
+};
+
+static inline struct ib_reg_wr *reg_wr(struct ib_send_wr *wr)
+{
+	return container_of(wr, struct ib_reg_wr, wr);
+}
+
 struct ib_bind_mw_wr {
 	struct ib_send_wr	wr;
 	struct ib_mw		*mw;
@@ -1369,6 +1383,9 @@ struct ib_mr {
 	struct ib_uobject *uobject;
 	u32		   lkey;
 	u32		   rkey;
+	u64		   iova;
+	u32		   length;
+	unsigned int	   page_size;
 	atomic_t	   usecnt; /* count number of MWs */
 };
 
@@ -1753,6 +1770,9 @@ struct ib_device {
 	struct ib_mr *		   (*alloc_mr)(struct ib_pd *pd,
 					       enum ib_mr_type mr_type,
 					       u32 max_num_sg);
+	int                        (*map_mr_sg)(struct ib_mr *mr,
+						struct scatterlist *sg,
+						int sg_nents);
 	struct ib_fast_reg_page_list * (*alloc_fast_reg_page_list)(struct ib_device *device,
 								   int page_list_len);
 	void			   (*free_fast_reg_page_list)(struct ib_fast_reg_page_list *page_list);
@@ -3059,4 +3079,28 @@ struct net_device *ib_get_net_dev_by_params(struct ib_device *dev, u8 port,
 					    u16 pkey, const union ib_gid *gid,
 					    const struct sockaddr *addr);
 
+int ib_map_mr_sg(struct ib_mr *mr,
+		 struct scatterlist *sg,
+		 int sg_nents,
+		 unsigned int page_size);
+
+static inline int
+ib_map_mr_sg_zbva(struct ib_mr *mr,
+		  struct scatterlist *sg,
+		  int sg_nents,
+		  unsigned int page_size)
+{
+	int n;
+
+	n = ib_map_mr_sg(mr, sg, sg_nents, page_size);
+	mr->iova = 0;
+
+	return n;
+}
+
+int ib_sg_to_pages(struct ib_mr *mr,
+		   struct scatterlist *sgl,
+		   int sg_nents,
+		   int (*set_page)(struct ib_mr *, u64));
+
 #endif /* IB_VERBS_H */