IB/hfi1: Add OPFN helper functions for TID RDMA feature

This patch adds the OPFN helper functions to initialize, encode, decode,
and reset OPFN parameters for the TID RDMA feature.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Mitko Haralanov <mitko.haralanov@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 202 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/hfi1/tid_rdma.c b/drivers/infiniband/hw/hfi1/tid_rdma.c
index da1ecb68a928..a8fd66f31fee 100644
--- a/drivers/infiniband/hw/hfi1/tid_rdma.c
+++ b/drivers/infiniband/hw/hfi1/tid_rdma.c
@@ -8,6 +8,208 @@
 #include "verbs.h"
 #include "tid_rdma.h"
 
+/*
+ * J_KEY for kernel contexts when TID RDMA is used.
+ * See generate_jkey() in hfi.h for more information.
+ */
+#define TID_RDMA_JKEY                   32
+#define HFI1_KERNEL_MIN_JKEY HFI1_ADMIN_JKEY_RANGE
+#define HFI1_KERNEL_MAX_JKEY (2 * HFI1_ADMIN_JKEY_RANGE - 1)
+
+#define TID_RDMA_MAX_READ_SEGS_PER_REQ  6
+#define TID_RDMA_MAX_WRITE_SEGS_PER_REQ 4
+
+#define TID_OPFN_QP_CTXT_MASK 0xff
+#define TID_OPFN_QP_CTXT_SHIFT 56
+#define TID_OPFN_QP_KDETH_MASK 0xff
+#define TID_OPFN_QP_KDETH_SHIFT 48
+#define TID_OPFN_MAX_LEN_MASK 0x7ff
+#define TID_OPFN_MAX_LEN_SHIFT 37
+#define TID_OPFN_TIMEOUT_MASK 0x1f
+#define TID_OPFN_TIMEOUT_SHIFT 32
+#define TID_OPFN_RESERVED_MASK 0x3f
+#define TID_OPFN_RESERVED_SHIFT 26
+#define TID_OPFN_URG_MASK 0x1
+#define TID_OPFN_URG_SHIFT 25
+#define TID_OPFN_VER_MASK 0x7
+#define TID_OPFN_VER_SHIFT 22
+#define TID_OPFN_JKEY_MASK 0x3f
+#define TID_OPFN_JKEY_SHIFT 16
+#define TID_OPFN_MAX_READ_MASK 0x3f
+#define TID_OPFN_MAX_READ_SHIFT 10
+#define TID_OPFN_MAX_WRITE_MASK 0x3f
+#define TID_OPFN_MAX_WRITE_SHIFT 4
+
+/*
+ * OPFN TID layout
+ *
+ * 63               47               31               15
+ * NNNNNNNNKKKKKKKK MMMMMMMMMMMTTTTT DDDDDDUVVVJJJJJJ RRRRRRWWWWWWCCCC
+ * 3210987654321098 7654321098765432 1098765432109876 5432109876543210
+ * N - the context Number
+ * K - the Kdeth_qp
+ * M - Max_len
+ * T - Timeout
+ * D - reserveD
+ * V - version
+ * U - Urg capable
+ * J - Jkey
+ * R - max_Read
+ * W - max_Write
+ * C - Capcode
+ */
+
+static u64 tid_rdma_opfn_encode(struct tid_rdma_params *p)
+{
+	return
+		(((u64)p->qp & TID_OPFN_QP_CTXT_MASK) <<
+			TID_OPFN_QP_CTXT_SHIFT) |
+		((((u64)p->qp >> 16) & TID_OPFN_QP_KDETH_MASK) <<
+			TID_OPFN_QP_KDETH_SHIFT) |
+		(((u64)((p->max_len >> PAGE_SHIFT) - 1) &
+			TID_OPFN_MAX_LEN_MASK) << TID_OPFN_MAX_LEN_SHIFT) |
+		(((u64)p->timeout & TID_OPFN_TIMEOUT_MASK) <<
+			TID_OPFN_TIMEOUT_SHIFT) |
+		(((u64)p->urg & TID_OPFN_URG_MASK) << TID_OPFN_URG_SHIFT) |
+		(((u64)p->jkey & TID_OPFN_JKEY_MASK) << TID_OPFN_JKEY_SHIFT) |
+		(((u64)p->max_read & TID_OPFN_MAX_READ_MASK) <<
+			TID_OPFN_MAX_READ_SHIFT) |
+		(((u64)p->max_write & TID_OPFN_MAX_WRITE_MASK) <<
+			TID_OPFN_MAX_WRITE_SHIFT);
+}
+
+static void tid_rdma_opfn_decode(struct tid_rdma_params *p, u64 data)
+{
+	p->max_len = (((data >> TID_OPFN_MAX_LEN_SHIFT) &
+		TID_OPFN_MAX_LEN_MASK) + 1) << PAGE_SHIFT;
+	p->jkey = (data >> TID_OPFN_JKEY_SHIFT) & TID_OPFN_JKEY_MASK;
+	p->max_write = (data >> TID_OPFN_MAX_WRITE_SHIFT) &
+		TID_OPFN_MAX_WRITE_MASK;
+	p->max_read = (data >> TID_OPFN_MAX_READ_SHIFT) &
+		TID_OPFN_MAX_READ_MASK;
+	p->qp =
+		((((data >> TID_OPFN_QP_KDETH_SHIFT) & TID_OPFN_QP_KDETH_MASK)
+			<< 16) |
+		((data >> TID_OPFN_QP_CTXT_SHIFT) & TID_OPFN_QP_CTXT_MASK));
+	p->urg = (data >> TID_OPFN_URG_SHIFT) & TID_OPFN_URG_MASK;
+	p->timeout = (data >> TID_OPFN_TIMEOUT_SHIFT) & TID_OPFN_TIMEOUT_MASK;
+}
+
+void tid_rdma_opfn_init(struct rvt_qp *qp, struct tid_rdma_params *p)
+{
+	struct hfi1_qp_priv *priv = qp->priv;
+
+	p->qp = (kdeth_qp << 16) | priv->rcd->ctxt;
+	p->max_len = TID_RDMA_MAX_SEGMENT_SIZE;
+	p->jkey = priv->rcd->jkey;
+	p->max_read = TID_RDMA_MAX_READ_SEGS_PER_REQ;
+	p->max_write = TID_RDMA_MAX_WRITE_SEGS_PER_REQ;
+	p->timeout = qp->timeout;
+	p->urg = is_urg_masked(priv->rcd);
+}
+
+bool tid_rdma_conn_req(struct rvt_qp *qp, u64 *data)
+{
+	struct hfi1_qp_priv *priv = qp->priv;
+
+	*data = tid_rdma_opfn_encode(&priv->tid_rdma.local);
+	return true;
+}
+
+bool tid_rdma_conn_reply(struct rvt_qp *qp, u64 data)
+{
+	struct hfi1_qp_priv *priv = qp->priv;
+	struct tid_rdma_params *remote, *old;
+	bool ret = true;
+
+	old = rcu_dereference_protected(priv->tid_rdma.remote,
+					lockdep_is_held(&priv->opfn.lock));
+	data &= ~0xfULL;
+	/*
+	 * If data passed in is zero, return true so as not to continue the
+	 * negotiation process
+	 */
+	if (!data || !HFI1_CAP_IS_KSET(TID_RDMA))
+		goto null;
+	/*
+	 * If kzalloc fails, return false. This will result in:
+	 * * at the requester a new OPFN request being generated to retry
+	 *   the negotiation
+	 * * at the responder, 0 being returned to the requester so as to
+	 *   disable TID RDMA at both the requester and the responder
+	 */
+	remote = kzalloc(sizeof(*remote), GFP_ATOMIC);
+	if (!remote) {
+		ret = false;
+		goto null;
+	}
+
+	tid_rdma_opfn_decode(remote, data);
+	priv->tid_timer_timeout_jiffies =
+		usecs_to_jiffies((((4096UL * (1UL << remote->timeout)) /
+				   1000UL) << 3) * 7);
+	rcu_assign_pointer(priv->tid_rdma.remote, remote);
+	/*
+	 * A TID RDMA READ request's segment size is not equal to
+	 * remote->max_len only when the request's data length is smaller
+	 * than remote->max_len. In that case, there will be only one segment.
+	 * Therefore, when priv->pkts_ps is used to calculate req->cur_seg
+	 * during retry, it will lead to req->cur_seg = 0, which is exactly
+	 * what is expected.
+	 */
+	priv->pkts_ps = (u16)rvt_div_mtu(qp, remote->max_len);
+	priv->timeout_shift = ilog2(priv->pkts_ps - 1) + 1;
+	goto free;
+null:
+	RCU_INIT_POINTER(priv->tid_rdma.remote, NULL);
+	priv->timeout_shift = 0;
+free:
+	if (old)
+		kfree_rcu(old, rcu_head);
+	return ret;
+}
+
+bool tid_rdma_conn_resp(struct rvt_qp *qp, u64 *data)
+{
+	bool ret;
+
+	ret = tid_rdma_conn_reply(qp, *data);
+	*data = 0;
+	/*
+	 * If tid_rdma_conn_reply() returns error, set *data as 0 to indicate
+	 * TID RDMA could not be enabled. This will result in TID RDMA being
+	 * disabled at the requester too.
+	 */
+	if (ret)
+		(void)tid_rdma_conn_req(qp, data);
+	return ret;
+}
+
+void tid_rdma_conn_error(struct rvt_qp *qp)
+{
+	struct hfi1_qp_priv *priv = qp->priv;
+	struct tid_rdma_params *old;
+
+	old = rcu_dereference_protected(priv->tid_rdma.remote,
+					lockdep_is_held(&priv->opfn.lock));
+	RCU_INIT_POINTER(priv->tid_rdma.remote, NULL);
+	if (old)
+		kfree_rcu(old, rcu_head);
+}
+
+/* This is called at context initialization time */
+int hfi1_kern_exp_rcv_init(struct hfi1_ctxtdata *rcd, int reinit)
+{
+	if (reinit)
+		return 0;
+
+	BUILD_BUG_ON(TID_RDMA_JKEY < HFI1_KERNEL_MIN_JKEY);
+	BUILD_BUG_ON(TID_RDMA_JKEY > HFI1_KERNEL_MAX_JKEY);
+	rcd->jkey = TID_RDMA_JKEY;
+	hfi1_set_ctxt_jkey(rcd->dd, rcd, rcd->jkey);
+	return 0;
+}
+
 /**
  * qp_to_rcd - determine the receive context used by a qp
  * @qp - the qp