RDMA/core: Add signature attrs element for ib_mr structure

This element will describe the needed characteristics for the signature
operation per signature enabled memory region (type IB_MR_TYPE_INTEGRITY).
Also add meta_length attribute to ib_sig_attrs structure for saving the
mapped metadata length (needed for the new API implementation).
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/uverbs_cmd.c

@@ -747,6 +747,7 @@ static int ib_uverbs_reg_mr(struct uverbs_attr_bundle *attrs)
 	mr->pd      = pd;
 	mr->type    = IB_MR_TYPE_USER;
 	mr->dm	    = NULL;
+	mr->sig_attrs = NULL;
 	mr->uobject = uobj;
 	atomic_inc(&pd->usecnt);
 	mr->res.type = RDMA_RESTRACK_MR;

drivers/infiniband/core/verbs.c

@@ -1976,6 +1976,7 @@ int ib_dereg_mr_user(struct ib_mr *mr, struct ib_udata *udata)
 {
 	struct ib_pd *pd = mr->pd;
 	struct ib_dm *dm = mr->dm;
+	struct ib_sig_attrs *sig_attrs = mr->sig_attrs;
 	int ret;
 
 	rdma_restrack_del(&mr->res);
@@ -1984,6 +1985,7 @@ int ib_dereg_mr_user(struct ib_mr *mr, struct ib_udata *udata)
 		atomic_dec(&pd->usecnt);
 		if (dm)
 			atomic_dec(&dm->usecnt);
+		kfree(sig_attrs);
 	}
 
 	return ret;
@@ -2025,6 +2027,7 @@ struct ib_mr *ib_alloc_mr_user(struct ib_pd *pd, enum ib_mr_type mr_type,
 		mr->res.type = RDMA_RESTRACK_MR;
 		rdma_restrack_kadd(&mr->res);
 		mr->type = mr_type;
+		mr->sig_attrs = NULL;
 	}
 
 	return mr;
@@ -2048,6 +2051,7 @@ struct ib_mr *ib_alloc_mr_integrity(struct ib_pd *pd,
 				    u32 max_num_meta_sg)
 {
 	struct ib_mr *mr;
+	struct ib_sig_attrs *sig_attrs;
 
 	if (!pd->device->ops.alloc_mr_integrity ||
 	    !pd->device->ops.map_mr_sg_pi)
@@ -2056,10 +2060,16 @@ struct ib_mr *ib_alloc_mr_integrity(struct ib_pd *pd,
 	if (!max_num_meta_sg)
 		return ERR_PTR(-EINVAL);
 
+	sig_attrs = kzalloc(sizeof(struct ib_sig_attrs), GFP_KERNEL);
+	if (!sig_attrs)
+		return ERR_PTR(-ENOMEM);
+
 	mr = pd->device->ops.alloc_mr_integrity(pd, max_num_data_sg,
 						max_num_meta_sg);
-	if (IS_ERR(mr))
+	if (IS_ERR(mr)) {
+		kfree(sig_attrs);
 		return mr;
+	}
 
 	mr->device = pd->device;
 	mr->pd = pd;
@@ -2070,6 +2080,7 @@ struct ib_mr *ib_alloc_mr_integrity(struct ib_pd *pd,
 	mr->res.type = RDMA_RESTRACK_MR;
 	rdma_restrack_kadd(&mr->res);
 	mr->type = IB_MR_TYPE_INTEGRITY;
+	mr->sig_attrs = sig_attrs;
 
 	return mr;
 }

include/rdma/ib_verbs.h

@@ -1739,7 +1739,7 @@ struct ib_mr {
 	};
 
 	struct ib_dm      *dm;
-
+	struct ib_sig_attrs *sig_attrs; /* only for IB_MR_TYPE_INTEGRITY MRs */
 	/*
 	 * Implementation details of the RDMA core, don't use in drivers:
 	 */

include/rdma/signature.h

@@ -80,11 +80,13 @@ struct ib_sig_domain {
  * @check_mask: bitmask for signature byte check (8 bytes)
  * @mem: memory domain layout descriptor.
  * @wire: wire domain layout descriptor.
+ * @meta_length: metadata length
  */
 struct ib_sig_attrs {
 	u8			check_mask;
 	struct ib_sig_domain	mem;
 	struct ib_sig_domain	wire;
+	int			meta_length;
 };
 
 enum ib_sig_err_type {