Commit 0a0bcb04 authored by Mike Marciniszyn's avatar Mike Marciniszyn Committed by Doug Ledford
Browse files

IB/hfi1: Fix loss of BECN with AHG 



AHG may be armed to use the stored header, which by design is limited
to edits in the PSN/A 32 bit word (bth2).

When the code is trying to send a BECN, the use of the stored header
will lose the BECN bit.

Fix by avoiding AHG when getting ready to send a BECN. This is
accomplished by always claiming the packet is not a middle packet which
is an AHG precursor.  BECNs are not a normal case and this should not
hurt AHG optimizations.

Cc: <stable@vger.kernel.org> # 4.14.x
Reviewed-by: default avatarMichael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: default avatarMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: default avatarDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent 5da9e742

drivers/infiniband/hw/hfi1/ruc.c

+40 −10
Original line number Diff line number Diff line
@@ -733,6 +733,20 @@ static inline void hfi1_make_ruc_bth(struct rvt_qp *qp, 
	ohdr->bth[2] = cpu_to_be32(bth2);

}



/**

 * hfi1_make_ruc_header_16B - build a 16B header

 * @qp: the queue pair

 * @ohdr: a pointer to the destination header memory

 * @bth0: bth0 passed in from the RC/UC builder

 * @bth2: bth2 passed in from the RC/UC builder

 * @middle: non zero implies indicates ahg "could" be used

 * @ps: the current packet state

 *

 * This routine may disarm ahg under these situations:

 * - packet needs a GRH

 * - BECN needed

 * - migration state not IB_MIG_MIGRATED

 */

static inline void hfi1_make_ruc_header_16B(struct rvt_qp *qp,

					    struct ib_other_headers *ohdr,

					    u32 bth0, u32 bth2, int middle,
@@ -777,6 +791,12 @@ static inline void hfi1_make_ruc_header_16B(struct rvt_qp *qp, 
	else

		middle = 0;



	if (qp->s_flags & RVT_S_ECN) {

		qp->s_flags &= ~RVT_S_ECN;

		/* we recently received a FECN, so return a BECN */

		becn = true;

		middle = 0;

	}

	if (middle)

		build_ahg(qp, bth2);

	else
@@ -784,11 +804,6 @@ static inline void hfi1_make_ruc_header_16B(struct rvt_qp *qp, 


	bth0 |= pkey;

	bth0 |= extra_bytes << 20;

	if (qp->s_flags & RVT_S_ECN) {

		qp->s_flags &= ~RVT_S_ECN;

		/* we recently received a FECN, so return a BECN */

		becn = true;

	}

	hfi1_make_ruc_bth(qp, ohdr, bth0, bth1, bth2);



	if (!ppd->lid)
@@ -806,6 +821,20 @@ static inline void hfi1_make_ruc_header_16B(struct rvt_qp *qp, 
			  pkey, becn, 0, l4, priv->s_sc);

}



/**

 * hfi1_make_ruc_header_9B - build a 9B header

 * @qp: the queue pair

 * @ohdr: a pointer to the destination header memory

 * @bth0: bth0 passed in from the RC/UC builder

 * @bth2: bth2 passed in from the RC/UC builder

 * @middle: non zero implies indicates ahg "could" be used

 * @ps: the current packet state

 *

 * This routine may disarm ahg under these situations:

 * - packet needs a GRH

 * - BECN needed

 * - migration state not IB_MIG_MIGRATED

 */

static inline void hfi1_make_ruc_header_9B(struct rvt_qp *qp,

					   struct ib_other_headers *ohdr,

					   u32 bth0, u32 bth2, int middle,
@@ -839,6 +868,12 @@ static inline void hfi1_make_ruc_header_9B(struct rvt_qp *qp, 
	else

		middle = 0;



	if (qp->s_flags & RVT_S_ECN) {

		qp->s_flags &= ~RVT_S_ECN;

		/* we recently received a FECN, so return a BECN */

		bth1 |= (IB_BECN_MASK << IB_BECN_SHIFT);

		middle = 0;

	}

	if (middle)

		build_ahg(qp, bth2);

	else
@@ -846,11 +881,6 @@ static inline void hfi1_make_ruc_header_9B(struct rvt_qp *qp, 


	bth0 |= pkey;

	bth0 |= extra_bytes << 20;

	if (qp->s_flags & RVT_S_ECN) {

		qp->s_flags &= ~RVT_S_ECN;

		/* we recently received a FECN, so return a BECN */

		bth1 |= (IB_BECN_MASK << IB_BECN_SHIFT);

	}

	hfi1_make_ruc_bth(qp, ohdr, bth0, bth1, bth2);

	hfi1_make_ib_hdr(&ps->s_txreq->phdr.hdr.ibh,

			 lrh0,

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