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Commit 4dd72636 authored by Amrani, Ram's avatar Amrani, Ram Committed by Doug Ledford
Browse files

RDMA/qedr: destroy CQ only after HW releases it 



Wait for all relevant CNQ interrupts before freeing the CQ.
Don't invoke completion handlers for a destroyed CQ.

Signed-off-by: default avatarRam Amrani <Ram.Amrani@cavium.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent 942b3b2c

drivers/infiniband/hw/qedr/main.c

+9 −2
Original line number Diff line number Diff line
@@ -438,14 +438,21 @@ static irqreturn_t qedr_irq_handler(int irq, void *handle) 


		cq->arm_flags = 0;



		if (cq->ibcq.comp_handler)

		if (!cq->destroyed && cq->ibcq.comp_handler)

			(*cq->ibcq.comp_handler)

				(&cq->ibcq, cq->ibcq.cq_context);



		/* The CQ's CNQ notification counter is checked before

		 * destroying the CQ in a busy-wait loop that waits for all of

		 * the CQ's CNQ interrupts to be processed. It is increased

		 * here, only after the completion handler, to ensure that the

		 * the handler is not running when the CQ is destroyed.

		 */

		cq->cnq_notif++;



		sw_comp_cons = qed_chain_get_cons_idx(&cnq->pbl);



		cnq->n_comp++;



	}



	qed_ops->rdma_cnq_prod_update(cnq->dev->rdma_ctx, cnq->index,

drivers/infiniband/hw/qedr/qedr.h

+2 −0
Original line number Diff line number Diff line
@@ -272,6 +272,8 @@ struct qedr_cq { 
	u32 cq_cons;



	struct qedr_userq q;

	u8 destroyed;

	u16 cnq_notif;

};



struct qedr_pd {

drivers/infiniband/hw/qedr/verbs.c

+64 −0
Original line number Diff line number Diff line
@@ -822,6 +822,17 @@ int qedr_arm_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags flags) 
{

	struct qedr_cq *cq = get_qedr_cq(ibcq);

	unsigned long sflags;

	struct qedr_dev *dev;



	dev = get_qedr_dev(ibcq->device);



	if (cq->destroyed) {

		DP_ERR(dev,

		       "warning: arm was invoked after destroy for cq %p (icid=%d)\n",

		       cq, cq->icid);

		return -EINVAL;

	}





	if (cq->cq_type == QEDR_CQ_TYPE_GSI)

		return 0;
@@ -987,16 +998,22 @@ int qedr_resize_cq(struct ib_cq *ibcq, int new_cnt, struct ib_udata *udata) 
	return 0;

}



#define QEDR_DESTROY_CQ_MAX_ITERATIONS		(10)

#define QEDR_DESTROY_CQ_ITER_DURATION		(10)



int qedr_destroy_cq(struct ib_cq *ibcq)

{

	struct qedr_dev *dev = get_qedr_dev(ibcq->device);

	struct qed_rdma_destroy_cq_out_params oparams;

	struct qed_rdma_destroy_cq_in_params iparams;

	struct qedr_cq *cq = get_qedr_cq(ibcq);

	int iter;

	int rc;



	DP_DEBUG(dev, QEDR_MSG_CQ, "destroy cq %p (icid=%d)\n", cq, cq->icid);



	cq->destroyed = 1;



	/* GSIs CQs are handled by driver, so they don't exist in the FW */

	if (cq->cq_type == QEDR_CQ_TYPE_GSI)

		goto done;
@@ -1013,10 +1030,50 @@ int qedr_destroy_cq(struct ib_cq *ibcq) 
		ib_umem_release(cq->q.umem);

	}



	/* We don't want the IRQ handler to handle a non-existing CQ so we

	 * wait until all CNQ interrupts, if any, are received. This will always

	 * happen and will always happen very fast. If not, then a serious error

	 * has occured. That is why we can use a long delay.

	 * We spin for a short time so we don’t lose time on context switching

	 * in case all the completions are handled in that span. Otherwise

	 * we sleep for a while and check again. Since the CNQ may be

	 * associated with (only) the current CPU we use msleep to allow the

	 * current CPU to be freed.

	 * The CNQ notification is increased in qedr_irq_handler().

	 */

	iter = QEDR_DESTROY_CQ_MAX_ITERATIONS;

	while (oparams.num_cq_notif != READ_ONCE(cq->cnq_notif) && iter) {

		udelay(QEDR_DESTROY_CQ_ITER_DURATION);

		iter--;

	}



	iter = QEDR_DESTROY_CQ_MAX_ITERATIONS;

	while (oparams.num_cq_notif != READ_ONCE(cq->cnq_notif) && iter) {

		msleep(QEDR_DESTROY_CQ_ITER_DURATION);

		iter--;

	}



	if (oparams.num_cq_notif != cq->cnq_notif)

		goto err;



	/* Note that we don't need to have explicit code to wait for the

	 * completion of the event handler because it is invoked from the EQ.

	 * Since the destroy CQ ramrod has also been received on the EQ we can

	 * be certain that there's no event handler in process.

	 */

done:

	cq->sig = ~cq->sig;



	kfree(cq);



	return 0;



err:

	DP_ERR(dev,

	       "CQ %p (icid=%d) not freed, expecting %d ints but got %d ints\n",

	       cq, cq->icid, oparams.num_cq_notif, cq->cnq_notif);



	return -EINVAL;

}



static inline int get_gid_info_from_table(struct ib_qp *ibqp,
@@ -3419,6 +3476,13 @@ int qedr_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc) 
	int update = 0;

	int done = 0;



	if (cq->destroyed) {

		DP_ERR(dev,

		       "warning: poll was invoked after destroy for cq %p (icid=%d)\n",

		       cq, cq->icid);

		return 0;

	}



	if (cq->cq_type == QEDR_CQ_TYPE_GSI)

		return qedr_gsi_poll_cq(ibcq, num_entries, wc);