diff options
| author | Chuck Lever | 2017-08-28 15:06:14 -0400 |
|---|---|---|
| committer | J. Bruce Fields | 2017-09-05 15:15:30 -0400 |
| commit | 0062818298662d0d05061949d12880146b5ebd65 (patch) | |
| tree | 50f9a9d6b223eba747b65857157a87bdb1356c2c /drivers/infiniband | |
| parent | 5a25bfd28c321e522dbe8083ad6219fa2a820610 (diff) | |
rdma core: Add rdma_rw_mr_payload()
The amount of payload per MR depends on device capabilities and
the memory registration mode in use. The new rdma_rw API hides both,
making it difficult for ULPs to determine how large their transport
send queues need to be.
Expose the MR payload information via a new API.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/core/rw.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/infiniband/core/rw.c b/drivers/infiniband/core/rw.c index dbfd854c32c9..6ca607e8e293 100644 --- a/drivers/infiniband/core/rw.c +++ b/drivers/infiniband/core/rw.c @@ -643,6 +643,30 @@ void rdma_rw_ctx_destroy_signature(struct rdma_rw_ctx *ctx, struct ib_qp *qp, } EXPORT_SYMBOL(rdma_rw_ctx_destroy_signature); +/** + * rdma_rw_mr_factor - return number of MRs required for a payload + * @device: device handling the connection + * @port_num: port num to which the connection is bound + * @maxpages: maximum payload pages per rdma_rw_ctx + * + * Returns the number of MRs the device requires to move @maxpayload + * bytes. The returned value is used during transport creation to + * compute max_rdma_ctxts and the size of the transport's Send and + * Send Completion Queues. + */ +unsigned int rdma_rw_mr_factor(struct ib_device *device, u8 port_num, + unsigned int maxpages) +{ + unsigned int mr_pages; + + if (rdma_rw_can_use_mr(device, port_num)) + mr_pages = rdma_rw_fr_page_list_len(device); + else + mr_pages = device->attrs.max_sge_rd; + return DIV_ROUND_UP(maxpages, mr_pages); +} +EXPORT_SYMBOL(rdma_rw_mr_factor); + void rdma_rw_init_qp(struct ib_device *dev, struct ib_qp_init_attr *attr) { u32 factor; |