diff mbox series

[07/20] RDMA/mlx5: Add attr for max number page list length for PI operation

Message ID 1559222731-16715-8-git-send-email-maxg@mellanox.com (mailing list archive)
State Superseded
Headers show
Series Introduce new API for T10-PI offload | expand

Commit Message

Max Gurtovoy May 30, 2019, 1:25 p.m. UTC 
PI offload (protection information) is a feature that each RDMA provider
can implement differently. Thus, introduce new device attribute to define
the maximal length of the page list for PI fast registration operation. For
example, mlx5 driver uses a single internal MR to map both data and
protection SGL's, so it's equal to max_fast_reg_page_list_len / 2.

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
---
 drivers/infiniband/hw/mlx5/main.c | 2 ++
 include/rdma/ib_verbs.h           | 1 +
 2 files changed, 3 insertions(+)

Comments

Sagi Grimberg June 5, 2019, 7:28 p.m. UTC | #1 
> +	props->max_pi_fast_reg_page_list_len =
> +		props->max_fast_reg_page_list_len / 2;

is it page_list_len or sg_list_len? Also need to document that
both data and meta sges need to fit in this (and not respectively)
Max Gurtovoy June 5, 2019, 9:44 p.m. UTC | #2 
On 6/5/2019 10:28 PM, Sagi Grimberg wrote:
>
>> + props->max_pi_fast_reg_page_list_len =
>> +        props->max_fast_reg_page_list_len / 2;
>
> is it page_list_len or sg_list_len? Also need to document that
> both data and meta sges need to fit in this (and not respectively)


in iSER:


  if (iser_conn->ib_conn.pi_support)
                 max_num_sg = attr->max_pi_fast_reg_page_list_len;
         else
                 max_num_sg = attr->max_fast_reg_page_list_len;


so max_pi_fast_reg_page_list_len is the length of *each* list in case we 
do PI (not the sum of the 2 lists length), the same way as 
max_fast_reg_page_list_len is the length of the list in the non-PI case.
Sagi Grimberg June 5, 2019, 10:36 p.m. UTC | #3 
>>> + props->max_pi_fast_reg_page_list_len =
>>> +        props->max_fast_reg_page_list_len / 2;
>>
>> is it page_list_len or sg_list_len? Also need to document that
>> both data and meta sges need to fit in this (and not respectively)
> 
> 
> in iSER:
> 
> 
>   if (iser_conn->ib_conn.pi_support)
>                  max_num_sg = attr->max_pi_fast_reg_page_list_len;
>          else
>                  max_num_sg = attr->max_fast_reg_page_list_len;
> 
> 
> so max_pi_fast_reg_page_list_len is the length of *each* list in case we 
> do PI (not the sum of the 2 lists length), the same way as 
> max_fast_reg_page_list_len is the length of the list in the non-PI case.

OK, I thought it was related to the fact that we use klms which are
twice the size of mtts.
diff mbox series

Patch

diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index b6588cdef1cf..7b48aeafef9e 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -1008,6 +1008,8 @@  static int mlx5_ib_query_device(struct ib_device *ibdev,
 	props->max_srq_sge	   = max_rq_sg - 1;
 	props->max_fast_reg_page_list_len =
 		1 << MLX5_CAP_GEN(mdev, log_max_klm_list_size);
+	props->max_pi_fast_reg_page_list_len =
+		props->max_fast_reg_page_list_len / 2;
 	get_atomic_caps_qp(dev, props);
 	props->masked_atomic_cap   = IB_ATOMIC_NONE;
 	props->max_mcast_grp	   = 1 << MLX5_CAP_GEN(mdev, log_max_mcg);
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 0a1713b86398..6e30ca4f1ef5 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -401,6 +401,7 @@  struct ib_device_attr {
 	int			max_srq_wr;
 	int			max_srq_sge;
 	unsigned int		max_fast_reg_page_list_len;
+	unsigned int		max_pi_fast_reg_page_list_len;
 	u16			max_pkeys;
 	u8			local_ca_ack_delay;
 	int			sig_prot_cap;