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Commit 977940b8 authored by Arthur Kepner's avatar Arthur Kepner Committed by Greg Kroah-Hartman
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staging/rdma/hfi1: optionally prescan rx queue for {B, F}ECNs - UC, RC 



To more rapidly respond to Explicit Congestion Notifications, prescan the
receive queue, and process FECNs, and BECNs first.  When a UC, or RC packet
containing a FECN, or BECN is found, immediately react to the ECN (either by
returning a CNP, or adjusting the injection rate). Afterward, the packet will
be processed normally.

Reviewed-by: default avatarMike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: default avatarDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: default avatarArthur Kepner <arthur.kepner@intel.com>
Signed-off-by: default avatarIra Weiny <ira.weiny@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3e7ccca0

drivers/staging/rdma/hfi1/driver.c

+32 −32
Original line number Diff line number Diff line
@@ -436,59 +436,58 @@ static inline void init_packet(struct hfi1_ctxtdata *rcd, 


#ifndef CONFIG_PRESCAN_RXQ

static void prescan_rxq(struct hfi1_packet *packet) {}

#else /* CONFIG_PRESCAN_RXQ */

#else /* !CONFIG_PRESCAN_RXQ */

static int prescan_receive_queue;



static void process_ecn(struct hfi1_qp *qp, struct hfi1_ib_header *hdr,

			struct hfi1_other_headers *ohdr,

			u64 rhf, struct ib_grh *grh)

			u64 rhf, u32 bth1, struct ib_grh *grh)

{

	struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);

	u32 bth1;

	u32 rqpn = 0;

	u16 rlid;

	u8 sc5, svc_type;

	int is_fecn, is_becn;



	switch (qp->ibqp.qp_type) {

	case IB_QPT_SMI:

	case IB_QPT_GSI:

	case IB_QPT_UD:

		rlid = be16_to_cpu(hdr->lrh[3]);

		rqpn = be32_to_cpu(ohdr->u.ud.deth[1]) & HFI1_QPN_MASK;

		svc_type = IB_CC_SVCTYPE_UD;

		break;

	case IB_QPT_UC:	/* LATER */

	case IB_QPT_RC:	/* LATER */

	case IB_QPT_UC:

		rlid = qp->remote_ah_attr.dlid;

		rqpn = qp->remote_qpn;

		svc_type = IB_CC_SVCTYPE_UC;

		break;

	case IB_QPT_RC:

		rlid = qp->remote_ah_attr.dlid;

		rqpn = qp->remote_qpn;

		svc_type = IB_CC_SVCTYPE_RC;

		break;

	default:

		return;

	}



	is_fecn = (be32_to_cpu(ohdr->bth[1]) >> HFI1_FECN_SHIFT) &

			HFI1_FECN_MASK;

	is_becn = (be32_to_cpu(ohdr->bth[1]) >> HFI1_BECN_SHIFT) &

			HFI1_BECN_MASK;



	sc5 = (be16_to_cpu(hdr->lrh[0]) >> 12) & 0xf;

	if (rhf_dc_info(rhf))

		sc5 |= 0x10;



	if (is_fecn) {

		u32 src_qpn = be32_to_cpu(ohdr->u.ud.deth[1]) & HFI1_QPN_MASK;

	if (bth1 & HFI1_FECN_SMASK) {

		u16 pkey = (u16)be32_to_cpu(ohdr->bth[0]);

		u16 dlid = be16_to_cpu(hdr->lrh[1]);

		u16 slid = be16_to_cpu(hdr->lrh[3]);



		return_cnp(ibp, qp, src_qpn, pkey, dlid, slid, sc5, grh);

		return_cnp(ibp, qp, rqpn, pkey, dlid, rlid, sc5, grh);

	}



	if (is_becn) {

	if (bth1 & HFI1_BECN_SMASK) {

		struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);

		u32 lqpn =  be32_to_cpu(ohdr->bth[1]) & HFI1_QPN_MASK;

		u32 lqpn = bth1 & HFI1_QPN_MASK;

		u8 sl = ibp->sc_to_sl[sc5];



		process_becn(ppd, sl, 0, lqpn, 0, svc_type);

		process_becn(ppd, sl, rlid, lqpn, rqpn, svc_type);

	}



	/* turn off BECN, or FECN */

	bth1 = be32_to_cpu(ohdr->bth[1]);

	bth1 &= ~(HFI1_FECN_MASK << HFI1_FECN_SHIFT);

	bth1 &= ~(HFI1_BECN_MASK << HFI1_BECN_SHIFT);

	ohdr->bth[1] = cpu_to_be32(bth1);

}



struct ps_mdata {
@@ -508,7 +507,6 @@ static inline void init_ps_mdata(struct ps_mdata *mdata, 
	mdata->rcd = rcd;

	mdata->rsize = packet->rsize;

	mdata->maxcnt = packet->maxcnt;



	mdata->ps_head = packet->rhqoff;



	if (HFI1_CAP_IS_KSET(DMA_RTAIL)) {
@@ -564,7 +562,7 @@ static void prescan_rxq(struct hfi1_packet *packet) 
		struct hfi1_other_headers *ohdr;

		struct ib_grh *grh = NULL;

		u64 rhf = rhf_to_cpu(rhf_addr);

		u32 etype = rhf_rcv_type(rhf), qpn;

		u32 etype = rhf_rcv_type(rhf), qpn, bth1;

		int is_ecn = 0;

		u8 lnh;
@@ -586,15 +584,13 @@ static void prescan_rxq(struct hfi1_packet *packet) 
		} else

			goto next; /* just in case */



		is_ecn |= be32_to_cpu(ohdr->bth[1]) &

			(HFI1_FECN_MASK << HFI1_FECN_SHIFT);

		is_ecn |= be32_to_cpu(ohdr->bth[1]) &

			(HFI1_BECN_MASK << HFI1_BECN_SHIFT);

		bth1 = be32_to_cpu(ohdr->bth[1]);

		is_ecn = !!(bth1 & (HFI1_FECN_SMASK | HFI1_BECN_SMASK));



		if (!is_ecn)

			goto next;



		qpn = be32_to_cpu(ohdr->bth[1]) & HFI1_QPN_MASK;

		qpn = bth1 & HFI1_QPN_MASK;

		rcu_read_lock();

		qp = hfi1_lookup_qpn(ibp, qpn);
@@ -603,8 +599,12 @@ static void prescan_rxq(struct hfi1_packet *packet) 
			goto next;

		}



		process_ecn(qp, hdr, ohdr, rhf, grh);

		process_ecn(qp, hdr, ohdr, rhf, bth1, grh);

		rcu_read_unlock();



		/* turn off BECN, FECN */

		bth1 &= ~(HFI1_FECN_SMASK | HFI1_BECN_SMASK);

		ohdr->bth[1] = cpu_to_be32(bth1);

next:

		update_ps_mdata(&mdata);

	}

drivers/staging/rdma/hfi1/rc.c

+5 −5
Original line number Diff line number Diff line
@@ -1978,7 +1978,7 @@ void hfi1_rc_rcv(struct hfi1_packet *packet) 
	}



	psn = be32_to_cpu(ohdr->bth[2]);

	opcode = bth0 >> 24;

	opcode = (bth0 >> 24) & 0xff;



	/*

	 * Process responses (ACKs) before anything else.  Note that the
@@ -2391,19 +2391,19 @@ void hfi1_rc_hdrerr( 
	struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);

	int diff;

	u32 opcode;

	u32 psn;

	u32 psn, bth0;



	/* Check for GRH */

	ohdr = &hdr->u.oth;

	if (has_grh)

		ohdr = &hdr->u.l.oth;



	opcode = be32_to_cpu(ohdr->bth[0]);

	if (hfi1_ruc_check_hdr(ibp, hdr, has_grh, qp, opcode))

	bth0 = be32_to_cpu(ohdr->bth[0]);

	if (hfi1_ruc_check_hdr(ibp, hdr, has_grh, qp, bth0))

		return;



	psn = be32_to_cpu(ohdr->bth[2]);

	opcode >>= 24;

	opcode = (bth0 >> 24) & 0xff;



	/* Only deal with RDMA Writes for now */

	if (opcode < IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) {

drivers/staging/rdma/hfi1/uc.c

+9 −6
Original line number Diff line number Diff line
@@ -268,7 +268,7 @@ void hfi1_uc_rcv(struct hfi1_packet *packet) 
	u32 tlen = packet->tlen;

	struct hfi1_qp *qp = packet->qp;

	struct hfi1_other_headers *ohdr = packet->ohdr;

	u32 opcode;

	u32 bth0, opcode;

	u32 hdrsize = packet->hlen;

	u32 psn;

	u32 pad;
@@ -278,10 +278,9 @@ void hfi1_uc_rcv(struct hfi1_packet *packet) 
	int has_grh = rcv_flags & HFI1_HAS_GRH;

	int ret;

	u32 bth1;

	struct ib_grh *grh = NULL;



	opcode = be32_to_cpu(ohdr->bth[0]);

	if (hfi1_ruc_check_hdr(ibp, hdr, has_grh, qp, opcode))

	bth0 = be32_to_cpu(ohdr->bth[0]);

	if (hfi1_ruc_check_hdr(ibp, hdr, has_grh, qp, bth0))

		return;



	bth1 = be32_to_cpu(ohdr->bth[1]);
@@ -303,6 +302,7 @@ void hfi1_uc_rcv(struct hfi1_packet *packet) 
		}



		if (bth1 & HFI1_FECN_SMASK) {

			struct ib_grh *grh = NULL;

			u16 pkey = (u16)be32_to_cpu(ohdr->bth[0]);

			u16 slid = be16_to_cpu(hdr->lrh[3]);

			u16 dlid = be16_to_cpu(hdr->lrh[1]);
@@ -310,13 +310,16 @@ void hfi1_uc_rcv(struct hfi1_packet *packet) 
			u8 sc5;



			sc5 = ibp->sl_to_sc[qp->remote_ah_attr.sl];

			if (has_grh)

				grh = &hdr->u.l.grh;



			return_cnp(ibp, qp, src_qp, pkey, dlid, slid, sc5, grh);

			return_cnp(ibp, qp, src_qp, pkey, dlid, slid, sc5,

				   grh);

		}

	}



	psn = be32_to_cpu(ohdr->bth[2]);

	opcode >>= 24;

	opcode = (bth0 >> 24) & 0xff;



	/* Compare the PSN verses the expected PSN. */

	if (unlikely(cmp_psn(psn, qp->r_psn) != 0)) {

drivers/staging/rdma/hfi1/verbs.c

+35 −6
Original line number Diff line number Diff line
@@ -2152,11 +2152,40 @@ void hfi1_schedule_send(struct hfi1_qp *qp) 
void hfi1_cnp_rcv(struct hfi1_packet *packet)

{

	struct hfi1_ibport *ibp = &packet->rcd->ppd->ibport_data;



	if (packet->qp->ibqp.qp_type == IB_QPT_UC)

		hfi1_uc_rcv(packet);

	else if (packet->qp->ibqp.qp_type == IB_QPT_UD)

		hfi1_ud_rcv(packet);

	else

	struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);

	struct hfi1_ib_header *hdr = packet->hdr;

	struct hfi1_qp *qp = packet->qp;

	u32 lqpn, rqpn = 0;

	u16 rlid = 0;

	u8 sl, sc5, sc4_bit, svc_type;

	bool sc4_set = has_sc4_bit(packet);



	switch (packet->qp->ibqp.qp_type) {

	case IB_QPT_UC:

		rlid = qp->remote_ah_attr.dlid;

		rqpn = qp->remote_qpn;

		svc_type = IB_CC_SVCTYPE_UC;

		break;

	case IB_QPT_RC:

		rlid = qp->remote_ah_attr.dlid;

		rqpn = qp->remote_qpn;

		svc_type = IB_CC_SVCTYPE_RC;

		break;

	case IB_QPT_SMI:

	case IB_QPT_GSI:

	case IB_QPT_UD:

		svc_type = IB_CC_SVCTYPE_UD;

		break;

	default:

		ibp->n_pkt_drops++;

		return;

	}



	sc4_bit = sc4_set << 4;

	sc5 = (be16_to_cpu(hdr->lrh[0]) >> 12) & 0xf;

	sc5 |= sc4_bit;

	sl = ibp->sc_to_sl[sc5];

	lqpn = qp->ibqp.qp_num;



	process_becn(ppd, sl, rlid, lqpn, rqpn, svc_type);

}