Commit 246d8b18 authored by Sagi Grimberg's avatar Sagi Grimberg Committed by Doug Ledford
Browse files

IB/cq: Don't force IB_POLL_DIRECT poll context for ib_process_cq_direct 



polling the completion queue directly does not interfere
with the existing polling logic, hence drop the requirement.
Be aware that running ib_process_cq_direct with non IB_POLL_DIRECT
CQ may trigger concurrent CQ processing.

This can be used for polling mode ULPs.

Cc: Bart Van Assche <bart.vanassche@wdc.com>
Reported-by: default avatarSteve Wise <swise@opengridcomputing.com>
Signed-off-by: default avatarSagi Grimberg <sagi@grimberg.me>
[maxg: added wcs array argument to __ib_process_cq]
Signed-off-by: default avatarMax Gurtovoy <maxg@mellanox.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent aaebd377

drivers/infiniband/core/cq.c

+13 −10
Original line number Diff line number Diff line
@@ -25,9 +25,10 @@ 
#define IB_POLL_FLAGS \

	(IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS)



static int __ib_process_cq(struct ib_cq *cq, int budget)

static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc *poll_wc)

{

	int i, n, completed = 0;

	struct ib_wc *wcs = poll_wc ? : cq->wc;



	/*

	 * budget might be (-1) if the caller does not
@@ -35,9 +36,9 @@ static int __ib_process_cq(struct ib_cq *cq, int budget) 
	 * minimum here.

	 */

	while ((n = ib_poll_cq(cq, min_t(u32, IB_POLL_BATCH,

			budget - completed), cq->wc)) > 0) {

			budget - completed), wcs)) > 0) {

		for (i = 0; i < n; i++) {

			struct ib_wc *wc = &cq->wc[i];

			struct ib_wc *wc = &wcs[i];



			if (wc->wr_cqe)

				wc->wr_cqe->done(cq, wc);
@@ -60,18 +61,20 @@ static int __ib_process_cq(struct ib_cq *cq, int budget) 
 * @cq:		CQ to process

 * @budget:	number of CQEs to poll for

 *

 * This function is used to process all outstanding CQ entries on a

 * %IB_POLL_DIRECT CQ.  It does not offload CQ processing to a different

 * context and does not ask for completion interrupts from the HCA.

 * This function is used to process all outstanding CQ entries.

 * It does not offload CQ processing to a different context and does

 * not ask for completion interrupts from the HCA.

 * Using direct processing on CQ with non IB_POLL_DIRECT type may trigger

 * concurrent processing.

 *

 * Note: do not pass -1 as %budget unless it is guaranteed that the number

 * of completions that will be processed is small.

 */

int ib_process_cq_direct(struct ib_cq *cq, int budget)

{

	WARN_ON_ONCE(cq->poll_ctx != IB_POLL_DIRECT);

	struct ib_wc wcs[IB_POLL_BATCH];



	return __ib_process_cq(cq, budget);

	return __ib_process_cq(cq, budget, wcs);

}

EXPORT_SYMBOL(ib_process_cq_direct);
@@ -85,7 +88,7 @@ static int ib_poll_handler(struct irq_poll *iop, int budget) 
	struct ib_cq *cq = container_of(iop, struct ib_cq, iop);

	int completed;



	completed = __ib_process_cq(cq, budget);

	completed = __ib_process_cq(cq, budget, NULL);

	if (completed < budget) {

		irq_poll_complete(&cq->iop);

		if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
@@ -105,7 +108,7 @@ static void ib_cq_poll_work(struct work_struct *work) 
	struct ib_cq *cq = container_of(work, struct ib_cq, work);

	int completed;



	completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE);

	completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE, NULL);

	if (completed >= IB_POLL_BUDGET_WORKQUEUE ||

	    ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)

		queue_work(ib_comp_wq, &cq->work);

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