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Commit 26ed687f authored by Joachim Fenkes's avatar Joachim Fenkes Committed by Roland Dreier
Browse files

IB/ehca: Change idr spinlocks into rwlocks 



This eliminates lock contention among IRQs as well as the need to
disable IRQs around idr_find, because there are no IRQ writers.

Signed-off-by: default avatarJoachim Fenkes <fenkes@de.ibm.com>
Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent 28db6beb

drivers/infiniband/hw/ehca/ehca_classes.h

+2 −2
Original line number Diff line number Diff line
@@ -293,8 +293,8 @@ void ehca_cleanup_av_cache(void); 
int ehca_init_mrmw_cache(void);

void ehca_cleanup_mrmw_cache(void);



extern spinlock_t ehca_qp_idr_lock;

extern spinlock_t ehca_cq_idr_lock;

extern rwlock_t ehca_qp_idr_lock;

extern rwlock_t ehca_cq_idr_lock;

extern struct idr ehca_qp_idr;

extern struct idr ehca_cq_idr;

drivers/infiniband/hw/ehca/ehca_cq.c

+6 −6
Original line number Diff line number Diff line
@@ -163,9 +163,9 @@ struct ib_cq *ehca_create_cq(struct ib_device *device, int cqe, int comp_vector, 
			goto create_cq_exit1;

		}



		spin_lock_irqsave(&ehca_cq_idr_lock, flags);

		write_lock_irqsave(&ehca_cq_idr_lock, flags);

		ret = idr_get_new(&ehca_cq_idr, my_cq, &my_cq->token);

		spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);

		write_unlock_irqrestore(&ehca_cq_idr_lock, flags);



	} while (ret == -EAGAIN);
@@ -294,9 +294,9 @@ struct ib_cq *ehca_create_cq(struct ib_device *device, int cqe, int comp_vector, 
			 "cq_num=%x h_ret=%lx", my_cq, my_cq->cq_number, h_ret);



create_cq_exit2:

	spin_lock_irqsave(&ehca_cq_idr_lock, flags);

	write_lock_irqsave(&ehca_cq_idr_lock, flags);

	idr_remove(&ehca_cq_idr, my_cq->token);

	spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);

	write_unlock_irqrestore(&ehca_cq_idr_lock, flags);



create_cq_exit1:

	kmem_cache_free(cq_cache, my_cq);
@@ -334,9 +334,9 @@ int ehca_destroy_cq(struct ib_cq *cq) 
	 * remove the CQ from the idr first to make sure

	 * no more interrupt tasklets will touch this CQ

	 */

	spin_lock_irqsave(&ehca_cq_idr_lock, flags);

	write_lock_irqsave(&ehca_cq_idr_lock, flags);

	idr_remove(&ehca_cq_idr, my_cq->token);

	spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);

	write_unlock_irqrestore(&ehca_cq_idr_lock, flags);



	/* now wait until all pending events have completed */

	wait_event(my_cq->wait_completion, !atomic_read(&my_cq->nr_events));

drivers/infiniband/hw/ehca/ehca_irq.c

+8 −11
Original line number Diff line number Diff line
@@ -180,12 +180,11 @@ static void qp_event_callback(struct ehca_shca *shca, 
{

	struct ib_event event;

	struct ehca_qp *qp;

	unsigned long flags;

	u32 token = EHCA_BMASK_GET(EQE_QP_TOKEN, eqe);



	spin_lock_irqsave(&ehca_qp_idr_lock, flags);

	read_lock(&ehca_qp_idr_lock);

	qp = idr_find(&ehca_qp_idr, token);

	spin_unlock_irqrestore(&ehca_qp_idr_lock, flags);

	read_unlock(&ehca_qp_idr_lock);





	if (!qp)
@@ -209,14 +208,13 @@ static void cq_event_callback(struct ehca_shca *shca, 
			      u64 eqe)

{

	struct ehca_cq *cq;

	unsigned long flags;

	u32 token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe);



	spin_lock_irqsave(&ehca_cq_idr_lock, flags);

	read_lock(&ehca_cq_idr_lock);

	cq = idr_find(&ehca_cq_idr, token);

	if (cq)

		atomic_inc(&cq->nr_events);

	spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);

	read_unlock(&ehca_cq_idr_lock);



	if (!cq)

		return;
@@ -411,7 +409,6 @@ static inline void process_eqe(struct ehca_shca *shca, struct ehca_eqe *eqe) 
{

	u64 eqe_value;

	u32 token;

	unsigned long flags;

	struct ehca_cq *cq;



	eqe_value = eqe->entry;
@@ -419,11 +416,11 @@ static inline void process_eqe(struct ehca_shca *shca, struct ehca_eqe *eqe) 
	if (EHCA_BMASK_GET(EQE_COMPLETION_EVENT, eqe_value)) {

		ehca_dbg(&shca->ib_device, "Got completion event");

		token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe_value);

		spin_lock_irqsave(&ehca_cq_idr_lock, flags);

		read_lock(&ehca_cq_idr_lock);

		cq = idr_find(&ehca_cq_idr, token);

		if (cq)

			atomic_inc(&cq->nr_events);

		spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);

		read_unlock(&ehca_cq_idr_lock);

		if (cq == NULL) {

			ehca_err(&shca->ib_device,

				 "Invalid eqe for non-existing cq token=%x",
@@ -480,11 +477,11 @@ void ehca_process_eq(struct ehca_shca *shca, int is_irq) 
		eqe_value = eqe_cache[eqe_cnt].eqe->entry;

		if (EHCA_BMASK_GET(EQE_COMPLETION_EVENT, eqe_value)) {

			token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe_value);

			spin_lock(&ehca_cq_idr_lock);

			read_lock(&ehca_cq_idr_lock);

			eqe_cache[eqe_cnt].cq = idr_find(&ehca_cq_idr, token);

			if (eqe_cache[eqe_cnt].cq)

				atomic_inc(&eqe_cache[eqe_cnt].cq->nr_events);

			spin_unlock(&ehca_cq_idr_lock);

			read_unlock(&ehca_cq_idr_lock);

			if (!eqe_cache[eqe_cnt].cq) {

				ehca_err(&shca->ib_device,

					 "Invalid eqe for non-existing cq "

drivers/infiniband/hw/ehca/ehca_main.c

+2 −2
Original line number Diff line number Diff line
@@ -96,8 +96,8 @@ MODULE_PARM_DESC(static_rate, 
MODULE_PARM_DESC(scaling_code,

		 "set scaling code (0: disabled/default, 1: enabled)");



DEFINE_SPINLOCK(ehca_qp_idr_lock);

DEFINE_SPINLOCK(ehca_cq_idr_lock);

DEFINE_RWLOCK(ehca_qp_idr_lock);

DEFINE_RWLOCK(ehca_cq_idr_lock);

DEFINE_IDR(ehca_qp_idr);

DEFINE_IDR(ehca_cq_idr);

drivers/infiniband/hw/ehca/ehca_qp.c

+6 −6
Original line number Diff line number Diff line
@@ -512,9 +512,9 @@ struct ehca_qp *internal_create_qp(struct ib_pd *pd, 
			goto create_qp_exit0;

		}



		spin_lock_irqsave(&ehca_qp_idr_lock, flags);

		write_lock_irqsave(&ehca_qp_idr_lock, flags);

		ret = idr_get_new(&ehca_qp_idr, my_qp, &my_qp->token);

		spin_unlock_irqrestore(&ehca_qp_idr_lock, flags);

		write_unlock_irqrestore(&ehca_qp_idr_lock, flags);



	} while (ret == -EAGAIN);
@@ -733,9 +733,9 @@ struct ehca_qp *internal_create_qp(struct ib_pd *pd, 
	hipz_h_destroy_qp(shca->ipz_hca_handle, my_qp);



create_qp_exit1:

	spin_lock_irqsave(&ehca_qp_idr_lock, flags);

	write_lock_irqsave(&ehca_qp_idr_lock, flags);

	idr_remove(&ehca_qp_idr, my_qp->token);

	spin_unlock_irqrestore(&ehca_qp_idr_lock, flags);

	write_unlock_irqrestore(&ehca_qp_idr_lock, flags);



create_qp_exit0:

	kmem_cache_free(qp_cache, my_qp);
@@ -1706,9 +1706,9 @@ int internal_destroy_qp(struct ib_device *dev, struct ehca_qp *my_qp, 
		}

	}



	spin_lock_irqsave(&ehca_qp_idr_lock, flags);

	write_lock_irqsave(&ehca_qp_idr_lock, flags);

	idr_remove(&ehca_qp_idr, my_qp->token);

	spin_unlock_irqrestore(&ehca_qp_idr_lock, flags);

	write_unlock_irqrestore(&ehca_qp_idr_lock, flags);



	h_ret = hipz_h_destroy_qp(shca->ipz_hca_handle, my_qp);

	if (h_ret != H_SUCCESS) {