IB/ipath: Support larger IB_QP_MAX_DEST_RD_ATOMIC and IB_QP_MAX_QP_RD_ATOMIC

This patch adds support for multiple RDMA reads and atomics to be sent
before an ACK is required to be seen by the requester.

Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ipath/ipath_qp.c

@@ -320,7 +320,8 @@ static void ipath_reset_qp(struct ipath_qp *qp)
 	qp->remote_qpn = 0;
 	qp->qkey = 0;
 	qp->qp_access_flags = 0;
-	clear_bit(IPATH_S_BUSY, &qp->s_flags);
+	qp->s_busy = 0;
+	qp->s_flags &= ~IPATH_S_SIGNAL_REQ_WR;
 	qp->s_hdrwords = 0;
 	qp->s_psn = 0;
 	qp->r_psn = 0;
@@ -333,7 +334,6 @@ static void ipath_reset_qp(struct ipath_qp *qp)
 		qp->r_state = IB_OPCODE_UC_SEND_LAST;
 	}
 	qp->s_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
-	qp->r_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
 	qp->r_nak_state = 0;
 	qp->r_wrid_valid = 0;
 	qp->s_rnr_timeout = 0;
@@ -344,6 +344,10 @@ static void ipath_reset_qp(struct ipath_qp *qp)
 	qp->s_ssn = 1;
 	qp->s_lsn = 0;
 	qp->s_wait_credit = 0;
+	memset(qp->s_ack_queue, 0, sizeof(qp->s_ack_queue));
+	qp->r_head_ack_queue = 0;
+	qp->s_tail_ack_queue = 0;
+	qp->s_num_rd_atomic = 0;
 	if (qp->r_rq.wq) {
 		qp->r_rq.wq->head = 0;
 		qp->r_rq.wq->tail = 0;
@@ -503,6 +507,10 @@ int ipath_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		    attr->path_mig_state != IB_MIG_REARM)
 			goto inval;
 
+	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
+		if (attr->max_dest_rd_atomic > IPATH_MAX_RDMA_ATOMIC)
+			goto inval;
+
 	switch (new_state) {
 	case IB_QPS_RESET:
 		ipath_reset_qp(qp);
@@ -559,6 +567,12 @@ int ipath_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 	if (attr_mask & IB_QP_QKEY)
 		qp->qkey = attr->qkey;
 
+	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
+		qp->r_max_rd_atomic = attr->max_dest_rd_atomic;
+
+	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC)
+		qp->s_max_rd_atomic = attr->max_rd_atomic;
+
 	qp->state = new_state;
 	spin_unlock_irqrestore(&qp->s_lock, flags);
 
@@ -598,8 +612,8 @@ int ipath_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 	attr->alt_pkey_index = 0;
 	attr->en_sqd_async_notify = 0;
 	attr->sq_draining = 0;
-	attr->max_rd_atomic = 1;
-	attr->max_dest_rd_atomic = 1;
+	attr->max_rd_atomic = qp->s_max_rd_atomic;
+	attr->max_dest_rd_atomic = qp->r_max_rd_atomic;
 	attr->min_rnr_timer = qp->r_min_rnr_timer;
 	attr->port_num = 1;
 	attr->timeout = qp->timeout;
@@ -614,7 +628,7 @@ int ipath_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 	init_attr->recv_cq = qp->ibqp.recv_cq;
 	init_attr->srq = qp->ibqp.srq;
 	init_attr->cap = attr->cap;
-	if (qp->s_flags & (1 << IPATH_S_SIGNAL_REQ_WR))
+	if (qp->s_flags & IPATH_S_SIGNAL_REQ_WR)
 		init_attr->sq_sig_type = IB_SIGNAL_REQ_WR;
 	else
 		init_attr->sq_sig_type = IB_SIGNAL_ALL_WR;
@@ -786,7 +800,7 @@ struct ib_qp *ipath_create_qp(struct ib_pd *ibpd,
 		qp->s_size = init_attr->cap.max_send_wr + 1;
 		qp->s_max_sge = init_attr->cap.max_send_sge;
 		if (init_attr->sq_sig_type == IB_SIGNAL_REQ_WR)
-			qp->s_flags = 1 << IPATH_S_SIGNAL_REQ_WR;
+			qp->s_flags = IPATH_S_SIGNAL_REQ_WR;
 		else
 			qp->s_flags = 0;
 		dev = to_idev(ibpd->device);

drivers/infiniband/hw/ipath/ipath_ruc.c

@@ -255,6 +255,7 @@ static void ipath_ruc_loopback(struct ipath_qp *sqp)
 	unsigned long flags;
 	struct ib_wc wc;
 	u64 sdata;
+	atomic64_t *maddr;
 
 	qp = ipath_lookup_qpn(&dev->qp_table, sqp->remote_qpn);
 	if (!qp) {
@@ -311,7 +312,7 @@ again:
 				sqp->s_rnr_retry--;
 			dev->n_rnr_naks++;
 			sqp->s_rnr_timeout =
-				ib_ipath_rnr_table[sqp->r_min_rnr_timer];
+				ib_ipath_rnr_table[qp->r_min_rnr_timer];
 			ipath_insert_rnr_queue(sqp);
 			goto done;
 		}
@@ -344,20 +345,22 @@ again:
 			wc.sl = sqp->remote_ah_attr.sl;
 			wc.dlid_path_bits = 0;
 			wc.port_num = 0;
+			spin_lock_irqsave(&sqp->s_lock, flags);
 			ipath_sqerror_qp(sqp, &wc);
+			spin_unlock_irqrestore(&sqp->s_lock, flags);
 			goto done;
 		}
 		break;
 
 	case IB_WR_RDMA_READ:
+		if (unlikely(!(qp->qp_access_flags &
+			       IB_ACCESS_REMOTE_READ)))
+			goto acc_err;
 		if (unlikely(!ipath_rkey_ok(qp, &sqp->s_sge, wqe->length,
 					    wqe->wr.wr.rdma.remote_addr,
 					    wqe->wr.wr.rdma.rkey,
 					    IB_ACCESS_REMOTE_READ)))
 			goto acc_err;
-		if (unlikely(!(qp->qp_access_flags &
-			       IB_ACCESS_REMOTE_READ)))
-			goto acc_err;
 		qp->r_sge.sge = wqe->sg_list[0];
 		qp->r_sge.sg_list = wqe->sg_list + 1;
 		qp->r_sge.num_sge = wqe->wr.num_sge;
@@ -365,22 +368,22 @@ again:
 
 	case IB_WR_ATOMIC_CMP_AND_SWP:
 	case IB_WR_ATOMIC_FETCH_AND_ADD:
+		if (unlikely(!(qp->qp_access_flags &
+			       IB_ACCESS_REMOTE_ATOMIC)))
+			goto acc_err;
 		if (unlikely(!ipath_rkey_ok(qp, &qp->r_sge, sizeof(u64),
-					    wqe->wr.wr.rdma.remote_addr,
-					    wqe->wr.wr.rdma.rkey,
+					    wqe->wr.wr.atomic.remote_addr,
+					    wqe->wr.wr.atomic.rkey,
 					    IB_ACCESS_REMOTE_ATOMIC)))
 			goto acc_err;
 		/* Perform atomic OP and save result. */
-		sdata = wqe->wr.wr.atomic.swap;
-		spin_lock_irqsave(&dev->pending_lock, flags);
-		qp->r_atomic_data = *(u64 *) qp->r_sge.sge.vaddr;
-		if (wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
-			*(u64 *) qp->r_sge.sge.vaddr =
-				qp->r_atomic_data + sdata;
-		else if (qp->r_atomic_data == wqe->wr.wr.atomic.compare_add)
-			*(u64 *) qp->r_sge.sge.vaddr = sdata;
-		spin_unlock_irqrestore(&dev->pending_lock, flags);
-		*(u64 *) sqp->s_sge.sge.vaddr = qp->r_atomic_data;
+		maddr = (atomic64_t *) qp->r_sge.sge.vaddr;
+		sdata = wqe->wr.wr.atomic.compare_add;
+		*(u64 *) sqp->s_sge.sge.vaddr =
+			(wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) ?
+			(u64) atomic64_add_return(sdata, maddr) - sdata :
+			(u64) cmpxchg((u64 *) qp->r_sge.sge.vaddr,
+				      sdata, wqe->wr.wr.atomic.swap);
 		goto send_comp;
 
 	default:
@@ -441,7 +444,7 @@ again:
 send_comp:
 	sqp->s_rnr_retry = sqp->s_rnr_retry_cnt;
 
-	if (!test_bit(IPATH_S_SIGNAL_REQ_WR, &sqp->s_flags) ||
+	if (!(sqp->s_flags & IPATH_S_SIGNAL_REQ_WR) ||
 	    (wqe->wr.send_flags & IB_SEND_SIGNALED)) {
 		wc.wr_id = wqe->wr.wr_id;
 		wc.status = IB_WC_SUCCESS;
@@ -503,7 +506,7 @@ void ipath_no_bufs_available(struct ipath_qp *qp, struct ipath_ibdev *dev)
 	 * We clear the tasklet flag now since we are committing to return
 	 * from the tasklet function.
 	 */
-	clear_bit(IPATH_S_BUSY, &qp->s_flags);
+	clear_bit(IPATH_S_BUSY, &qp->s_busy);
 	tasklet_unlock(&qp->s_task);
 	want_buffer(dev->dd);
 	dev->n_piowait++;
@@ -542,6 +545,9 @@ int ipath_post_ruc_send(struct ipath_qp *qp, struct ib_send_wr *wr)
 		    wr->sg_list[0].addr & (sizeof(u64) - 1))) {
 		ret = -EINVAL;
 		goto bail;
+	} else if (wr->opcode >= IB_WR_RDMA_READ && !qp->s_max_rd_atomic) {
+		ret = -EINVAL;
+		goto bail;
 	}
 	/* IB spec says that num_sge == 0 is OK. */
 	if (wr->num_sge > qp->s_max_sge) {
@@ -648,7 +654,7 @@ void ipath_do_ruc_send(unsigned long data)
 	u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
 	struct ipath_other_headers *ohdr;
 
-	if (test_and_set_bit(IPATH_S_BUSY, &qp->s_flags))
+	if (test_and_set_bit(IPATH_S_BUSY, &qp->s_busy))
 		goto bail;
 
 	if (unlikely(qp->remote_ah_attr.dlid == dev->dd->ipath_lid)) {
@@ -684,19 +690,15 @@ again:
 	 */
 	spin_lock_irqsave(&qp->s_lock, flags);
 
-	/* Sending responses has higher priority over sending requests. */
-	if (qp->s_ack_state != IB_OPCODE_RC_ACKNOWLEDGE &&
-	    (bth0 = ipath_make_rc_ack(qp, ohdr, pmtu)) != 0)
-		bth2 = qp->s_ack_psn++ & IPATH_PSN_MASK;
-	else if (!((qp->ibqp.qp_type == IB_QPT_RC) ?
-		   ipath_make_rc_req(qp, ohdr, pmtu, &bth0, &bth2) :
-		   ipath_make_uc_req(qp, ohdr, pmtu, &bth0, &bth2))) {
+	if (!((qp->ibqp.qp_type == IB_QPT_RC) ?
+	       ipath_make_rc_req(qp, ohdr, pmtu, &bth0, &bth2) :
+	       ipath_make_uc_req(qp, ohdr, pmtu, &bth0, &bth2))) {
 		/*
 		 * Clear the busy bit before unlocking to avoid races with
 		 * adding new work queue items and then failing to process
 		 * them.
 		 */
-		clear_bit(IPATH_S_BUSY, &qp->s_flags);
+		clear_bit(IPATH_S_BUSY, &qp->s_busy);
 		spin_unlock_irqrestore(&qp->s_lock, flags);
 		goto bail;
 	}
@@ -729,7 +731,7 @@ again:
 	goto again;
 
 clear:
-	clear_bit(IPATH_S_BUSY, &qp->s_flags);
+	clear_bit(IPATH_S_BUSY, &qp->s_busy);
 bail:
 	return;
 }

drivers/infiniband/hw/ipath/ipath_uc.c

@@ -42,7 +42,7 @@ static void complete_last_send(struct ipath_qp *qp, struct ipath_swqe *wqe,
 {
 	if (++qp->s_last == qp->s_size)
 		qp->s_last = 0;
-	if (!test_bit(IPATH_S_SIGNAL_REQ_WR, &qp->s_flags) ||
+	if (!(qp->s_flags & IPATH_S_SIGNAL_REQ_WR) ||
 	    (wqe->wr.send_flags & IB_SEND_SIGNALED)) {
 		wc->wr_id = wqe->wr.wr_id;
 		wc->status = IB_WC_SUCCESS;
@@ -344,13 +344,13 @@ void ipath_uc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
 	send_first:
 		if (qp->r_reuse_sge) {
 			qp->r_reuse_sge = 0;
-			qp->r_sge = qp->s_rdma_sge;
+			qp->r_sge = qp->s_rdma_read_sge;
 		} else if (!ipath_get_rwqe(qp, 0)) {
 			dev->n_pkt_drops++;
 			goto done;
 		}
 		/* Save the WQE so we can reuse it in case of an error. */
-		qp->s_rdma_sge = qp->r_sge;
+		qp->s_rdma_read_sge = qp->r_sge;
 		qp->r_rcv_len = 0;
 		if (opcode == OP(SEND_ONLY))
 			goto send_last;

drivers/infiniband/hw/ipath/ipath_ud.c

@@ -467,7 +467,7 @@ int ipath_post_ud_send(struct ipath_qp *qp, struct ib_send_wr *wr)
 
 done:
 	/* Queue the completion status entry. */
-	if (!test_bit(IPATH_S_SIGNAL_REQ_WR, &qp->s_flags) ||
+	if (!(qp->s_flags & IPATH_S_SIGNAL_REQ_WR) ||
 	    (wr->send_flags & IB_SEND_SIGNALED)) {
 		wc.wr_id = wr->wr_id;
 		wc.status = IB_WC_SUCCESS;

drivers/infiniband/hw/ipath/ipath_verbs.c

@@ -773,7 +773,6 @@ int ipath_verbs_send(struct ipath_devdata *dd, u32 hdrwords,
 	/* +1 is for the qword padding of pbc */
 	plen = hdrwords + ((len + 3) >> 2) + 1;
 	if (unlikely((plen << 2) > dd->ipath_ibmaxlen)) {
-		ipath_dbg("packet len 0x%x too long, failing\n", plen);
 		ret = -EINVAL;
 		goto bail;
 	}
@@ -980,14 +979,14 @@ static int ipath_query_device(struct ib_device *ibdev,
 	props->max_cqe = ib_ipath_max_cqes;
 	props->max_mr = dev->lk_table.max;
 	props->max_pd = ib_ipath_max_pds;
-	props->max_qp_rd_atom = 1;
-	props->max_qp_init_rd_atom = 1;
+	props->max_qp_rd_atom = IPATH_MAX_RDMA_ATOMIC;
+	props->max_qp_init_rd_atom = 255;
 	/* props->max_res_rd_atom */
 	props->max_srq = ib_ipath_max_srqs;
 	props->max_srq_wr = ib_ipath_max_srq_wrs;
 	props->max_srq_sge = ib_ipath_max_srq_sges;
 	/* props->local_ca_ack_delay */
-	props->atomic_cap = IB_ATOMIC_HCA;
+	props->atomic_cap = IB_ATOMIC_GLOB;
 	props->max_pkeys = ipath_get_npkeys(dev->dd);
 	props->max_mcast_grp = ib_ipath_max_mcast_grps;
 	props->max_mcast_qp_attach = ib_ipath_max_mcast_qp_attached;

drivers/infiniband/hw/ipath/ipath_verbs.h

@@ -43,6 +43,8 @@
 
 #include "ipath_layer.h"
 
+#define IPATH_MAX_RDMA_ATOMIC	4
+
 #define QPN_MAX                 (1 << 24)
 #define QPNMAP_ENTRIES          (QPN_MAX / PAGE_SIZE / BITS_PER_BYTE)
 
@@ -89,7 +91,7 @@ struct ib_reth {
 } __attribute__ ((packed));
 
 struct ib_atomic_eth {
-	__be64 vaddr;
+	__be32 vaddr[2];	/* unaligned so access as 2 32-bit words */
 	__be32 rkey;
 	__be64 swap_data;
 	__be64 compare_data;
@@ -108,7 +110,7 @@ struct ipath_other_headers {
 		} rc;
 		struct {
 			__be32 aeth;
-			__be64 atomic_ack_eth;
+			__be32 atomic_ack_eth[2];
 		} at;
 		__be32 imm_data;
 		__be32 aeth;
@@ -311,6 +313,19 @@ struct ipath_sge_state {
 	u8 num_sge;
 };
 
+/*
+ * This structure holds the information that the send tasklet needs
+ * to send a RDMA read response or atomic operation.
+ */
+struct ipath_ack_entry {
+	u8 opcode;
+	u32 psn;
+	union {
+		struct ipath_sge_state rdma_sge;
+		u64 atomic_data;
+	};
+};
+
 /*
  * Variables prefixed with s_ are for the requester (sender).
  * Variables prefixed with r_ are for the responder (receiver).
@@ -333,24 +348,24 @@ struct ipath_qp {
 	struct ipath_mmap_info *ip;
 	struct ipath_sge_state *s_cur_sge;
 	struct ipath_sge_state s_sge;	/* current send request data */
-	/* current RDMA read send data */
-	struct ipath_sge_state s_rdma_sge;
+	struct ipath_ack_entry s_ack_queue[IPATH_MAX_RDMA_ATOMIC + 1];
+	struct ipath_sge_state s_ack_rdma_sge;
+	struct ipath_sge_state s_rdma_read_sge;
 	struct ipath_sge_state r_sge;	/* current receive data */
 	spinlock_t s_lock;
-	unsigned long s_flags;
+	unsigned long s_busy;
 	u32 s_hdrwords;		/* size of s_hdr in 32 bit words */
 	u32 s_cur_size;		/* size of send packet in bytes */
 	u32 s_len;		/* total length of s_sge */
-	u32 s_rdma_len;		/* total length of s_rdma_sge */
+	u32 s_rdma_read_len;	/* total length of s_rdma_read_sge */
 	u32 s_next_psn;		/* PSN for next request */
 	u32 s_last_psn;		/* last response PSN processed */
 	u32 s_psn;		/* current packet sequence number */
-	u32 s_ack_psn;		/* PSN for RDMA_READ */
+	u32 s_ack_rdma_psn;	/* PSN for sending RDMA read responses */
+	u32 s_ack_psn;		/* PSN for acking sends and RDMA writes */
 	u32 s_rnr_timeout;	/* number of milliseconds for RNR timeout */
 	u32 r_ack_psn;		/* PSN for next ACK or atomic ACK */
 	u64 r_wr_id;		/* ID for current receive WQE */
-	u64 r_atomic_data;	/* data for last atomic op */
-	u32 r_atomic_psn;	/* PSN of last atomic op */
 	u32 r_len;		/* total length of r_sge */
 	u32 r_rcv_len;		/* receive data len processed */
 	u32 r_psn;		/* expected rcv packet sequence number */
@@ -360,12 +375,13 @@ struct ipath_qp {
 	u8 s_ack_state;		/* opcode of packet to ACK */
 	u8 s_nak_state;		/* non-zero if NAK is pending */
 	u8 r_state;		/* opcode of last packet received */
-	u8 r_ack_state;		/* opcode of packet to ACK */
 	u8 r_nak_state;		/* non-zero if NAK is pending */
 	u8 r_min_rnr_timer;	/* retry timeout value for RNR NAKs */
 	u8 r_reuse_sge;		/* for UC receive errors */
 	u8 r_sge_inx;		/* current index into sg_list */
 	u8 r_wrid_valid;	/* r_wrid set but CQ entry not yet made */
+	u8 r_max_rd_atomic;	/* max number of RDMA read/atomic to receive */
+	u8 r_head_ack_queue;	/* index into s_ack_queue[] */
 	u8 qp_access_flags;
 	u8 s_max_sge;		/* size of s_wq->sg_list */
 	u8 s_retry_cnt;		/* number of times to retry */
@@ -374,6 +390,10 @@ struct ipath_qp {
 	u8 s_rnr_retry;		/* requester RNR retry counter */
 	u8 s_wait_credit;	/* limit number of unacked packets sent */
 	u8 s_pkey_index;	/* PKEY index to use */
+	u8 s_max_rd_atomic;	/* max number of RDMA read/atomic to send */
+	u8 s_num_rd_atomic;	/* number of RDMA read/atomic pending */
+	u8 s_tail_ack_queue;	/* index into s_ack_queue[] */
+	u8 s_flags;
 	u8 timeout;		/* Timeout for this QP */
 	enum ib_mtu path_mtu;
 	u32 remote_qpn;
@@ -390,11 +410,16 @@ struct ipath_qp {
 	struct ipath_sge r_sg_list[0];	/* verified SGEs */
 };
 
+/* Bit definition for s_busy. */
+#define IPATH_S_BUSY		0
+
 /*
  * Bit definitions for s_flags.
  */
-#define IPATH_S_BUSY		0
-#define IPATH_S_SIGNAL_REQ_WR	1
+#define IPATH_S_SIGNAL_REQ_WR	0x01
+#define IPATH_S_FENCE_PENDING	0x02
+#define IPATH_S_RDMAR_PENDING	0x04
+#define IPATH_S_ACK_PENDING	0x08
 
 #define IPATH_PSN_CREDIT	2048
 
@@ -757,9 +782,6 @@ u32 ipath_make_grh(struct ipath_ibdev *dev, struct ib_grh *hdr,
 
 void ipath_do_ruc_send(unsigned long data);
 
-u32 ipath_make_rc_ack(struct ipath_qp *qp, struct ipath_other_headers *ohdr,
-		      u32 pmtu);
-
 int ipath_make_rc_req(struct ipath_qp *qp, struct ipath_other_headers *ohdr,
 		      u32 pmtu, u32 *bth0p, u32 *bth2p);