Commit 57e80e0b authored by Tyrel Datwyler's avatar Tyrel Datwyler Committed by Martin K. Petersen
Browse files

scsi: ibmvfc: Define per-queue state/list locks 

Define per-queue locks for protecting queue state and event pool sent/free
lists. The evt list lock is initially redundant but it allows the driver to
be modified in the follow-up patches to relax the queue locking around
submissions and completions.

Link: https://lore.kernel.org/r/20210106201835.1053593-4-tyreld@linux.ibm.com


Reviewed-by: default avatarBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: default avatarTyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent e4b26f3d

drivers/scsi/ibmvscsi/ibmvfc.c

+74 −19
Original line number Diff line number Diff line
@@ -176,8 +176,9 @@ static void ibmvfc_trc_start(struct ibmvfc_event *evt) 
	struct ibmvfc_mad_common *mad = &evt->iu.mad_common;

	struct ibmvfc_fcp_cmd_iu *iu = ibmvfc_get_fcp_iu(vhost, vfc_cmd);

	struct ibmvfc_trace_entry *entry;

	int index = atomic_inc_return(&vhost->trace_index) & IBMVFC_TRACE_INDEX_MASK;



	entry = &vhost->trace[vhost->trace_index++];

	entry = &vhost->trace[index];

	entry->evt = evt;

	entry->time = jiffies;

	entry->fmt = evt->crq.format;
@@ -211,8 +212,10 @@ static void ibmvfc_trc_end(struct ibmvfc_event *evt) 
	struct ibmvfc_mad_common *mad = &evt->xfer_iu->mad_common;

	struct ibmvfc_fcp_cmd_iu *iu = ibmvfc_get_fcp_iu(vhost, vfc_cmd);

	struct ibmvfc_fcp_rsp *rsp = ibmvfc_get_fcp_rsp(vhost, vfc_cmd);

	struct ibmvfc_trace_entry *entry = &vhost->trace[vhost->trace_index++];

	struct ibmvfc_trace_entry *entry;

	int index = atomic_inc_return(&vhost->trace_index) & IBMVFC_TRACE_INDEX_MASK;



	entry = &vhost->trace[index];

	entry->evt = evt;

	entry->time = jiffies;

	entry->fmt = evt->crq.format;
@@ -805,6 +808,7 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost) 
	} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));



	spin_lock_irqsave(vhost->host->host_lock, flags);

	spin_lock(vhost->crq.q_lock);

	vhost->state = IBMVFC_NO_CRQ;

	vhost->logged_in = 0;
@@ -821,6 +825,7 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost) 
		dev_warn(vhost->dev, "Partner adapter not ready\n");

	else if (rc != 0)

		dev_warn(vhost->dev, "Couldn't register crq (rc=%d)\n", rc);

	spin_unlock(vhost->crq.q_lock);

	spin_unlock_irqrestore(vhost->host->host_lock, flags);



	return rc;
@@ -853,10 +858,16 @@ static int ibmvfc_valid_event(struct ibmvfc_event_pool *pool, 
static void ibmvfc_free_event(struct ibmvfc_event *evt)

{

	struct ibmvfc_event_pool *pool = &evt->queue->evt_pool;

	unsigned long flags;



	BUG_ON(!ibmvfc_valid_event(pool, evt));

	BUG_ON(atomic_inc_return(&evt->free) != 1);



	spin_lock_irqsave(&evt->queue->l_lock, flags);

	list_add_tail(&evt->queue_list, &evt->queue->free);

	if (evt->eh_comp)

		complete(evt->eh_comp);

	spin_unlock_irqrestore(&evt->queue->l_lock, flags);

}



/**
@@ -875,12 +886,27 @@ static void ibmvfc_scsi_eh_done(struct ibmvfc_event *evt) 
		cmnd->scsi_done(cmnd);

	}



	if (evt->eh_comp)

		complete(evt->eh_comp);



	ibmvfc_free_event(evt);

}



/**

 * ibmvfc_complete_purge - Complete failed command list

 * @purge_list:		list head of failed commands

 *

 * This function runs completions on commands to fail as a result of a

 * host reset or platform migration. Caller must hold host_lock.

 **/

static void ibmvfc_complete_purge(struct list_head *purge_list)

{

	struct ibmvfc_event *evt, *pos;



	list_for_each_entry_safe(evt, pos, purge_list, queue_list) {

		list_del(&evt->queue_list);

		ibmvfc_trc_end(evt);

		evt->done(evt);

	}

}



/**

 * ibmvfc_fail_request - Fail request with specified error code

 * @evt:		ibmvfc event struct
@@ -897,10 +923,7 @@ static void ibmvfc_fail_request(struct ibmvfc_event *evt, int error_code) 
	} else

		evt->xfer_iu->mad_common.status = cpu_to_be16(IBMVFC_MAD_DRIVER_FAILED);



	list_del(&evt->queue_list);

	del_timer(&evt->timer);

	ibmvfc_trc_end(evt);

	evt->done(evt);

}



/**
@@ -914,10 +937,14 @@ static void ibmvfc_fail_request(struct ibmvfc_event *evt, int error_code) 
static void ibmvfc_purge_requests(struct ibmvfc_host *vhost, int error_code)

{

	struct ibmvfc_event *evt, *pos;

	unsigned long flags;



	ibmvfc_dbg(vhost, "Purging all requests\n");

	spin_lock_irqsave(&vhost->crq.l_lock, flags);

	list_for_each_entry_safe(evt, pos, &vhost->crq.sent, queue_list)

		ibmvfc_fail_request(evt, error_code);

	list_splice_init(&vhost->crq.sent, &vhost->purge);

	spin_unlock_irqrestore(&vhost->crq.l_lock, flags);

}



/**
@@ -1314,6 +1341,7 @@ static int ibmvfc_init_event_pool(struct ibmvfc_host *vhost, 


	INIT_LIST_HEAD(&queue->sent);

	INIT_LIST_HEAD(&queue->free);

	spin_lock_init(&queue->l_lock);



	for (i = 0; i < pool->size; ++i) {

		struct ibmvfc_event *evt = &pool->events[i];
@@ -1368,11 +1396,14 @@ static void ibmvfc_free_event_pool(struct ibmvfc_host *vhost, 
static struct ibmvfc_event *ibmvfc_get_event(struct ibmvfc_queue *queue)

{

	struct ibmvfc_event *evt;

	unsigned long flags;



	spin_lock_irqsave(&queue->l_lock, flags);

	BUG_ON(list_empty(&queue->free));

	evt = list_entry(queue->free.next, struct ibmvfc_event, queue_list);

	atomic_set(&evt->free, 0);

	list_del(&evt->queue_list);

	spin_unlock_irqrestore(&queue->l_lock, flags);

	return evt;

}
@@ -1506,6 +1537,7 @@ static int ibmvfc_send_event(struct ibmvfc_event *evt, 
			     struct ibmvfc_host *vhost, unsigned long timeout)

{

	__be64 *crq_as_u64 = (__be64 *) &evt->crq;

	unsigned long flags;

	int rc;



	/* Copy the IU into the transfer area */
@@ -1517,7 +1549,6 @@ static int ibmvfc_send_event(struct ibmvfc_event *evt, 
	else

		BUG();



	list_add_tail(&evt->queue_list, &evt->queue->sent);

	timer_setup(&evt->timer, ibmvfc_timeout, 0);



	if (timeout) {
@@ -1525,11 +1556,15 @@ static int ibmvfc_send_event(struct ibmvfc_event *evt, 
		add_timer(&evt->timer);

	}



	spin_lock_irqsave(&evt->queue->l_lock, flags);

	list_add_tail(&evt->queue_list, &evt->queue->sent);



	mb();



	if ((rc = ibmvfc_send_crq(vhost, be64_to_cpu(crq_as_u64[0]),

				  be64_to_cpu(crq_as_u64[1])))) {

		list_del(&evt->queue_list);

		spin_unlock_irqrestore(&evt->queue->l_lock, flags);

		del_timer(&evt->timer);



		/* If send_crq returns H_CLOSED, return SCSI_MLQUEUE_HOST_BUSY.
@@ -1554,8 +1589,10 @@ static int ibmvfc_send_event(struct ibmvfc_event *evt, 
			evt->xfer_iu->mad_common.status = cpu_to_be16(IBMVFC_MAD_CRQ_ERROR);



		evt->done(evt);

	} else

	} else {

		spin_unlock_irqrestore(&evt->queue->l_lock, flags);

		ibmvfc_trc_start(evt);

	}



	return 0;

}
@@ -1663,9 +1700,6 @@ static void ibmvfc_scsi_done(struct ibmvfc_event *evt) 
		cmnd->scsi_done(cmnd);

	}



	if (evt->eh_comp)

		complete(evt->eh_comp);



	ibmvfc_free_event(evt);

}
@@ -2219,28 +2253,28 @@ static int ibmvfc_wait_for_ops(struct ibmvfc_host *vhost, void *device, 
	ENTER;

	do {

		wait = 0;

		spin_lock_irqsave(vhost->host->host_lock, flags);

		spin_lock_irqsave(&vhost->crq.l_lock, flags);

		list_for_each_entry(evt, &vhost->crq.sent, queue_list) {

			if (match(evt, device)) {

				evt->eh_comp = &comp;

				wait++;

			}

		}

		spin_unlock_irqrestore(vhost->host->host_lock, flags);

		spin_unlock_irqrestore(&vhost->crq.l_lock, flags);



		if (wait) {

			timeout = wait_for_completion_timeout(&comp, timeout);



			if (!timeout) {

				wait = 0;

				spin_lock_irqsave(vhost->host->host_lock, flags);

				spin_lock_irqsave(&vhost->crq.l_lock, flags);

				list_for_each_entry(evt, &vhost->crq.sent, queue_list) {

					if (match(evt, device)) {

						evt->eh_comp = NULL;

						wait++;

					}

				}

				spin_unlock_irqrestore(vhost->host->host_lock, flags);

				spin_unlock_irqrestore(&vhost->crq.l_lock, flags);

				if (wait)

					dev_err(vhost->dev, "Timed out waiting for aborted commands\n");

				LEAVE;
@@ -2277,14 +2311,16 @@ static int ibmvfc_cancel_all(struct scsi_device *sdev, int type) 
	u16 status;



	ENTER;

	spin_lock_irqsave(vhost->host->host_lock, flags);

	found_evt = NULL;

	spin_lock_irqsave(vhost->host->host_lock, flags);

	spin_lock(&vhost->crq.l_lock);

	list_for_each_entry(evt, &vhost->crq.sent, queue_list) {

		if (evt->cmnd && evt->cmnd->device == sdev) {

			found_evt = evt;

			break;

		}

	}

	spin_unlock(&vhost->crq.l_lock);



	if (!found_evt) {

		if (vhost->log_level > IBMVFC_DEFAULT_LOG_LEVEL)
@@ -2414,14 +2450,16 @@ static int ibmvfc_abort_task_set(struct scsi_device *sdev) 
	unsigned long flags, timeout = IBMVFC_ABORT_TIMEOUT;

	int rsp_code = 0;



	spin_lock_irqsave(vhost->host->host_lock, flags);

	found_evt = NULL;

	spin_lock_irqsave(vhost->host->host_lock, flags);

	spin_lock(&vhost->crq.l_lock);

	list_for_each_entry(evt, &vhost->crq.sent, queue_list) {

		if (evt->cmnd && evt->cmnd->device == sdev) {

			found_evt = evt;

			break;

		}

	}

	spin_unlock(&vhost->crq.l_lock);



	if (!found_evt) {

		if (vhost->log_level > IBMVFC_DEFAULT_LOG_LEVEL)
@@ -2935,7 +2973,9 @@ static void ibmvfc_handle_crq(struct ibmvfc_crq *crq, struct ibmvfc_host *vhost) 
	}



	del_timer(&evt->timer);

	spin_lock(&evt->queue->l_lock);

	list_del(&evt->queue_list);

	spin_unlock(&evt->queue->l_lock);

	ibmvfc_trc_end(evt);

	evt->done(evt);

}
@@ -3328,6 +3368,7 @@ static void ibmvfc_tasklet(void *data) 
	int done = 0;



	spin_lock_irqsave(vhost->host->host_lock, flags);

	spin_lock(vhost->crq.q_lock);

	while (!done) {

		/* Pull all the valid messages off the async CRQ */

		while ((async = ibmvfc_next_async_crq(vhost)) != NULL) {
@@ -3358,6 +3399,7 @@ static void ibmvfc_tasklet(void *data) 
			done = 1;

	}



	spin_unlock(vhost->crq.q_lock);

	spin_unlock_irqrestore(vhost->host->host_lock, flags);

}
@@ -4734,6 +4776,7 @@ static void ibmvfc_do_work(struct ibmvfc_host *vhost) 
	struct ibmvfc_target *tgt;

	unsigned long flags;

	struct fc_rport *rport;

	LIST_HEAD(purge);

	int rc;



	ibmvfc_log_ae(vhost, vhost->events_to_log);
@@ -4746,6 +4789,8 @@ static void ibmvfc_do_work(struct ibmvfc_host *vhost) 
		break;

	case IBMVFC_HOST_ACTION_RESET:

		vhost->action = IBMVFC_HOST_ACTION_TGT_DEL;

		list_splice_init(&vhost->purge, &purge);

		ibmvfc_complete_purge(&purge);

		spin_unlock_irqrestore(vhost->host->host_lock, flags);

		rc = ibmvfc_reset_crq(vhost);

		spin_lock_irqsave(vhost->host->host_lock, flags);
@@ -4759,6 +4804,8 @@ static void ibmvfc_do_work(struct ibmvfc_host *vhost) 
		break;

	case IBMVFC_HOST_ACTION_REENABLE:

		vhost->action = IBMVFC_HOST_ACTION_TGT_DEL;

		list_splice_init(&vhost->purge, &purge);

		ibmvfc_complete_purge(&purge);

		spin_unlock_irqrestore(vhost->host->host_lock, flags);

		rc = ibmvfc_reenable_crq_queue(vhost);

		spin_lock_irqsave(vhost->host->host_lock, flags);
@@ -4936,6 +4983,9 @@ static int ibmvfc_alloc_queue(struct ibmvfc_host *vhost, 
	size_t fmt_size;



	ENTER;

	spin_lock_init(&queue->_lock);

	queue->q_lock = &queue->_lock;



	switch (fmt) {

	case IBMVFC_CRQ_FMT:

		fmt_size = sizeof(*queue->msgs.crq);
@@ -5098,6 +5148,7 @@ static int ibmvfc_alloc_mem(struct ibmvfc_host *vhost) 


	vhost->trace = kcalloc(IBMVFC_NUM_TRACE_ENTRIES,

			       sizeof(struct ibmvfc_trace_entry), GFP_KERNEL);

	atomic_set(&vhost->trace_index, -1);



	if (!vhost->trace)

		goto free_disc_buffer;
@@ -5214,6 +5265,7 @@ static int ibmvfc_probe(struct vio_dev *vdev, const struct vio_device_id *id) 


	vhost = shost_priv(shost);

	INIT_LIST_HEAD(&vhost->targets);

	INIT_LIST_HEAD(&vhost->purge);

	sprintf(vhost->name, IBMVFC_NAME);

	vhost->host = shost;

	vhost->dev = dev;
@@ -5298,6 +5350,7 @@ static int ibmvfc_probe(struct vio_dev *vdev, const struct vio_device_id *id) 
static int ibmvfc_remove(struct vio_dev *vdev)

{

	struct ibmvfc_host *vhost = dev_get_drvdata(&vdev->dev);

	LIST_HEAD(purge);

	unsigned long flags;



	ENTER;
@@ -5315,6 +5368,8 @@ static int ibmvfc_remove(struct vio_dev *vdev) 


	spin_lock_irqsave(vhost->host->host_lock, flags);

	ibmvfc_purge_requests(vhost, DID_ERROR);

	list_splice_init(&vhost->purge, &purge);

	ibmvfc_complete_purge(&purge);

	spin_unlock_irqrestore(vhost->host->host_lock, flags);

	ibmvfc_free_event_pool(vhost, &vhost->crq);

drivers/scsi/ibmvscsi/ibmvfc.h

+6 −1
Original line number Diff line number Diff line
@@ -768,10 +768,13 @@ struct ibmvfc_queue { 
	dma_addr_t msg_token;

	enum ibmvfc_msg_fmt fmt;

	int size, cur;

	spinlock_t _lock;

	spinlock_t *q_lock;



	struct ibmvfc_event_pool evt_pool;

	struct list_head sent;

	struct list_head free;

	spinlock_t l_lock;

};



enum ibmvfc_host_action {
@@ -808,11 +811,13 @@ struct ibmvfc_host { 
	enum ibmvfc_host_action action;

#define IBMVFC_NUM_TRACE_INDEX_BITS		8

#define IBMVFC_NUM_TRACE_ENTRIES		(1 << IBMVFC_NUM_TRACE_INDEX_BITS)

#define IBMVFC_TRACE_INDEX_MASK			(IBMVFC_NUM_TRACE_ENTRIES - 1)

#define IBMVFC_TRACE_SIZE	(sizeof(struct ibmvfc_trace_entry) * IBMVFC_NUM_TRACE_ENTRIES)

	struct ibmvfc_trace_entry *trace;

	u32 trace_index:IBMVFC_NUM_TRACE_INDEX_BITS;

	atomic_t trace_index;

	int num_targets;

	struct list_head targets;

	struct list_head purge;

	struct device *dev;

	struct dma_pool *sg_pool;

	mempool_t *tgt_pool;