void rdma_rw_init_qp(struct ib_device *dev, struct ib_qp_init_attr *attr)
{
u32 factor;
WARN_ON_ONCE(attr->port_num == 0);
/*
* Each context needs at least one RDMA READ or WRITE WR.
*
* For some hardware we might need more, eventually we should ask the
* HCA driver for a multiplier here.
*/
factor = 1;
/*
* If the devices needs MRs to perform RDMA READ or WRITE operations,
* we'll need two additional MRs for the registrations and the
* invalidation.
*/
if (attr->create_flags & IB_QP_CREATE_SIGNATURE_EN)
factor += 6; /* (inv + reg) * (data + prot + sig) */
else if (rdma_rw_can_use_mr(dev, attr->port_num))
factor += 2; /* inv + reg */
attr->cap.max_send_wr += factor * attr->cap.max_rdma_ctxs;
/*
* But maybe we were just too high in the sky and the device doesn't
* even support all we need, and we'll have to live with what we get..
*/
attr->cap.max_send_wr =
min_t(u32, attr->cap.max_send_wr, dev->attrs.max_qp_wr);
}
/**
* 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);
}
int rdma_rw_init_mrs(struct ib_qp *qp, struct ib_qp_init_attr *attr)
{
struct ib_device *dev = qp->pd->device;
u32 nr_mrs = 0, nr_sig_mrs = 0;
int ret = 0;
if (attr->create_flags & IB_QP_CREATE_SIGNATURE_EN) {
nr_sig_mrs = attr->cap.max_rdma_ctxs;
nr_mrs = attr->cap.max_rdma_ctxs * 2;
} else if (rdma_rw_can_use_mr(dev, attr->port_num)) {
nr_mrs = attr->cap.max_rdma_ctxs;
}
if (nr_mrs) {
ret = ib_mr_pool_init(qp, &qp->rdma_mrs, nr_mrs,
IB_MR_TYPE_MEM_REG,
rdma_rw_fr_page_list_len(dev));
if (ret) {
pr_err("%s: failed to allocated %d MRs\n",
__func__, nr_mrs);
return ret;
}
}
if (nr_sig_mrs) {
ret = ib_mr_pool_init(qp, &qp->sig_mrs, nr_sig_mrs,
IB_MR_TYPE_SIGNATURE, 2);
if (ret) {
pr_err("%s: failed to allocated %d SIG MRs\n",
__func__, nr_mrs);
goto out_free_rdma_mrs;
}
}
return 0;
out_free_rdma_mrs:
ib_mr_pool_destroy(qp, &qp->rdma_mrs);
return ret;
}
