RDMA: Update workqueue usage

* ib_wq is added, which is used as the common workqueue for infiniband
  instead of the system workqueue.  All system workqueue usages
  including flush_scheduled_work() callers are converted to use and
  flush ib_wq.

* cancel_delayed_work() + flush_scheduled_work() converted to
  cancel_delayed_work_sync().

* qib_wq is removed and ib_wq is used instead.

This is to prepare for deprecation of flush_scheduled_work().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/core/cache.c

@@ -308,7 +308,7 @@ static void ib_cache_event(struct ib_event_handler *handler,
 			INIT_WORK(&work->work, ib_cache_task);
 			work->device   = event->device;
 			work->port_num = event->element.port_num;
-			schedule_work(&work->work);
+			queue_work(ib_wq, &work->work);
 		}
 	}
 }
@@ -368,7 +368,7 @@ static void ib_cache_cleanup_one(struct ib_device *device)
 	int p;
 
 	ib_unregister_event_handler(&device->cache.event_handler);
-	flush_scheduled_work();
+	flush_workqueue(ib_wq);
 
 	for (p = 0; p <= end_port(device) - start_port(device); ++p) {
 		kfree(device->cache.pkey_cache[p]);

drivers/infiniband/core/device.c

@@ -38,7 +38,6 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/mutex.h>
-#include <linux/workqueue.h>
 
 #include "core_priv.h"
 
@@ -52,6 +51,9 @@ struct ib_client_data {
 	void *            data;
 };
 
+struct workqueue_struct *ib_wq;
+EXPORT_SYMBOL_GPL(ib_wq);
+
 static LIST_HEAD(device_list);
 static LIST_HEAD(client_list);
 
@@ -718,6 +720,10 @@ static int __init ib_core_init(void)
 {
 	int ret;
 
+	ib_wq = alloc_workqueue("infiniband", 0, 0);
+	if (!ib_wq)
+		return -ENOMEM;
+
 	ret = ib_sysfs_setup();
 	if (ret)
 		printk(KERN_WARNING "Couldn't create InfiniBand device class\n");
@@ -726,6 +732,7 @@ static int __init ib_core_init(void)
 	if (ret) {
 		printk(KERN_WARNING "Couldn't set up InfiniBand P_Key/GID cache\n");
 		ib_sysfs_cleanup();
+		destroy_workqueue(ib_wq);
 	}
 
 	return ret;
@@ -736,7 +743,7 @@ static void __exit ib_core_cleanup(void)
 	ib_cache_cleanup();
 	ib_sysfs_cleanup();
 	/* Make sure that any pending umem accounting work is done. */
-	flush_scheduled_work();
+	destroy_workqueue(ib_wq);
 }
 
 module_init(ib_core_init);

drivers/infiniband/core/sa_query.c

@@ -425,7 +425,7 @@ static void ib_sa_event(struct ib_event_handler *handler, struct ib_event *event
 		port->sm_ah = NULL;
 		spin_unlock_irqrestore(&port->ah_lock, flags);
 
-		schedule_work(&sa_dev->port[event->element.port_num -
+		queue_work(ib_wq, &sa_dev->port[event->element.port_num -
 					    sa_dev->start_port].update_task);
 	}
 }

drivers/infiniband/core/umem.c

@@ -262,7 +262,7 @@ void ib_umem_release(struct ib_umem *umem)
 			umem->mm   = mm;
 			umem->diff = diff;
 
-			schedule_work(&umem->work);
+			queue_work(ib_wq, &umem->work);
 			return;
 		}
 	} else

drivers/infiniband/hw/ipath/ipath_driver.c

@@ -755,7 +755,7 @@ static void __devexit ipath_remove_one(struct pci_dev *pdev)
 	 */
 	ipath_shutdown_device(dd);
 
-	flush_scheduled_work();
+	flush_workqueue(ib_wq);
 
 	if (dd->verbs_dev)
 		ipath_unregister_ib_device(dd->verbs_dev);

drivers/infiniband/hw/ipath/ipath_user_pages.c

@@ -220,7 +220,7 @@ void ipath_release_user_pages_on_close(struct page **p, size_t num_pages)
 	work->mm = mm;
 	work->num_pages = num_pages;
 
-	schedule_work(&work->work);
+	queue_work(ib_wq, &work->work);
 	return;
 
 bail_mm:

drivers/infiniband/hw/qib/qib_iba7220.c

@@ -1692,8 +1692,7 @@ static void qib_7220_quiet_serdes(struct qib_pportdata *ppd)
 	ppd->lflags &= ~QIBL_IB_AUTONEG_INPROG;
 	spin_unlock_irqrestore(&ppd->lflags_lock, flags);
 	wake_up(&ppd->cpspec->autoneg_wait);
-	cancel_delayed_work(&ppd->cpspec->autoneg_work);
+	cancel_delayed_work_sync(&ppd->cpspec->autoneg_work);
-	flush_scheduled_work();
 
 	shutdown_7220_relock_poll(ppd->dd);
 	val = qib_read_kreg64(ppd->dd, kr_xgxs_cfg);
@@ -3515,8 +3514,8 @@ static void try_7220_autoneg(struct qib_pportdata *ppd)
 
 	toggle_7220_rclkrls(ppd->dd);
 	/* 2 msec is minimum length of a poll cycle */
-	schedule_delayed_work(&ppd->cpspec->autoneg_work,
+	queue_delayed_work(ib_wq, &ppd->cpspec->autoneg_work,
-			      msecs_to_jiffies(2));
+			   msecs_to_jiffies(2));
 }
 
 /*

drivers/infiniband/hw/qib/qib_iba7322.c

@@ -2406,10 +2406,9 @@ static void qib_7322_mini_quiet_serdes(struct qib_pportdata *ppd)
 	ppd->lflags &= ~QIBL_IB_AUTONEG_INPROG;
 	spin_unlock_irqrestore(&ppd->lflags_lock, flags);
 	wake_up(&ppd->cpspec->autoneg_wait);
-	cancel_delayed_work(&ppd->cpspec->autoneg_work);
+	cancel_delayed_work_sync(&ppd->cpspec->autoneg_work);
 	if (ppd->dd->cspec->r1)
-		cancel_delayed_work(&ppd->cpspec->ipg_work);
+		cancel_delayed_work_sync(&ppd->cpspec->ipg_work);
-	flush_scheduled_work();
 
 	ppd->cpspec->chase_end = 0;
 	if (ppd->cpspec->chase_timer.data) /* if initted */
@@ -2706,7 +2705,7 @@ static noinline void unknown_7322_gpio_intr(struct qib_devdata *dd)
 			if (!(pins & mask)) {
 				++handled;
 				qd->t_insert = get_jiffies_64();
-				schedule_work(&qd->work);
+				queue_work(ib_wq, &qd->work);
 			}
 		}
 	}
@@ -4990,8 +4989,8 @@ static void try_7322_autoneg(struct qib_pportdata *ppd)
 	set_7322_ibspeed_fast(ppd, QIB_IB_DDR);
 	qib_7322_mini_pcs_reset(ppd);
 	/* 2 msec is minimum length of a poll cycle */
-	schedule_delayed_work(&ppd->cpspec->autoneg_work,
+	queue_delayed_work(ib_wq, &ppd->cpspec->autoneg_work,
-			      msecs_to_jiffies(2));
+			   msecs_to_jiffies(2));
 }
 
 /*
@@ -5121,7 +5120,8 @@ static void try_7322_ipg(struct qib_pportdata *ppd)
 		ib_free_send_mad(send_buf);
 retry:
 	delay = 2 << ppd->cpspec->ipg_tries;
-	schedule_delayed_work(&ppd->cpspec->ipg_work, msecs_to_jiffies(delay));
+	queue_delayed_work(ib_wq, &ppd->cpspec->ipg_work,
+			   msecs_to_jiffies(delay));
 }
 
 /*

drivers/infiniband/hw/qib/qib_init.c

@@ -80,7 +80,6 @@ unsigned qib_wc_pat = 1; /* default (1) is to use PAT, not MTRR */
 module_param_named(wc_pat, qib_wc_pat, uint, S_IRUGO);
 MODULE_PARM_DESC(wc_pat, "enable write-combining via PAT mechanism");
 
-struct workqueue_struct *qib_wq;
 struct workqueue_struct *qib_cq_wq;
 
 static void verify_interrupt(unsigned long);
@@ -1044,24 +1043,10 @@ static int __init qlogic_ib_init(void)
 	if (ret)
 		goto bail;
 
-	/*
-	 * We create our own workqueue mainly because we want to be
-	 * able to flush it when devices are being removed.  We can't
-	 * use schedule_work()/flush_scheduled_work() because both
-	 * unregister_netdev() and linkwatch_event take the rtnl lock,
-	 * so flush_scheduled_work() can deadlock during device
-	 * removal.
-	 */
-	qib_wq = create_workqueue("qib");
-	if (!qib_wq) {
-		ret = -ENOMEM;
-		goto bail_dev;
-	}
-
 	qib_cq_wq = create_singlethread_workqueue("qib_cq");
 	if (!qib_cq_wq) {
 		ret = -ENOMEM;
-		goto bail_wq;
+		goto bail_dev;
 	}
 
 	/*
@@ -1091,8 +1076,6 @@ static int __init qlogic_ib_init(void)
 	idr_destroy(&qib_unit_table);
 bail_cq_wq:
 	destroy_workqueue(qib_cq_wq);
-bail_wq:
-	destroy_workqueue(qib_wq);
 bail_dev:
 	qib_dev_cleanup();
 bail:
@@ -1116,7 +1099,6 @@ static void __exit qlogic_ib_cleanup(void)
 
 	pci_unregister_driver(&qib_driver);
 
-	destroy_workqueue(qib_wq);
 	destroy_workqueue(qib_cq_wq);
 
 	qib_cpulist_count = 0;
@@ -1289,7 +1271,7 @@ static int __devinit qib_init_one(struct pci_dev *pdev,
 
 	if (qib_mini_init || initfail || ret) {
 		qib_stop_timers(dd);
-		flush_scheduled_work();
+		flush_workqueue(ib_wq);
 		for (pidx = 0; pidx < dd->num_pports; ++pidx)
 			dd->f_quiet_serdes(dd->pport + pidx);
 		if (qib_mini_init)
@@ -1338,8 +1320,8 @@ static void __devexit qib_remove_one(struct pci_dev *pdev)
 
 	qib_stop_timers(dd);
 
-	/* wait until all of our (qsfp) schedule_work() calls complete */
+	/* wait until all of our (qsfp) queue_work() calls complete */
-	flush_scheduled_work();
+	flush_workqueue(ib_wq);
 
 	ret = qibfs_remove(dd);
 	if (ret)

drivers/infiniband/hw/qib/qib_qsfp.c

@@ -485,7 +485,7 @@ void qib_qsfp_init(struct qib_qsfp_data *qd,
 		goto bail;
 	/* We see a module, but it may be unwise to look yet. Just schedule */
 	qd->t_insert = get_jiffies_64();
-	schedule_work(&qd->work);
+	queue_work(ib_wq, &qd->work);
 bail:
 	return;
 }
@@ -493,10 +493,9 @@ void qib_qsfp_init(struct qib_qsfp_data *qd,
 void qib_qsfp_deinit(struct qib_qsfp_data *qd)
 {
 	/*
-	 * There is nothing to do here for now.  our
+	 * There is nothing to do here for now.  our work is scheduled
-	 * work is scheduled with schedule_work(), and
+	 * with queue_work(), and flush_workqueue() from remove_one
-	 * flush_scheduled_work() from remove_one will
+	 * will block until all work setup with queue_work()
-	 * block until all work ssetup with schedule_work()
 	 * completes.
 	 */
 }

drivers/infiniband/hw/qib/qib_verbs.h

@@ -805,7 +805,6 @@ static inline int qib_send_ok(struct qib_qp *qp)
 		 !(qp->s_flags & QIB_S_ANY_WAIT_SEND));
 }
 
-extern struct workqueue_struct *qib_wq;
 extern struct workqueue_struct *qib_cq_wq;
 
 /*
@@ -814,7 +813,7 @@ extern struct workqueue_struct *qib_cq_wq;
 static inline void qib_schedule_send(struct qib_qp *qp)
 {
 	if (qib_send_ok(qp))
-		queue_work(qib_wq, &qp->s_work);
+		queue_work(ib_wq, &qp->s_work);
 }
 
 static inline int qib_pkey_ok(u16 pkey1, u16 pkey2)

drivers/infiniband/ulp/srp/ib_srp.c

@@ -638,7 +638,7 @@ static int srp_reconnect_target(struct srp_target_port *target)
 	if (target->state == SRP_TARGET_CONNECTING) {
 		target->state = SRP_TARGET_DEAD;
 		INIT_WORK(&target->work, srp_remove_work);
-		schedule_work(&target->work);
+		queue_work(ib_wq, &target->work);
 	}
 	spin_unlock_irq(&target->lock);
 
@@ -2199,7 +2199,7 @@ static void srp_remove_one(struct ib_device *device)
 		 * started before we marked our target ports as
 		 * removed, and any target port removal tasks.
 		 */
-		flush_scheduled_work();
+		flush_workqueue(ib_wq);
 
 		list_for_each_entry_safe(target, tmp_target,
 					 &host->target_list, list) {

include/rdma/ib_verbs.h

@@ -47,10 +47,13 @@
 #include <linux/list.h>
 #include <linux/rwsem.h>
 #include <linux/scatterlist.h>
+#include <linux/workqueue.h>
 
 #include <asm/atomic.h>
 #include <asm/uaccess.h>
 
+extern struct workqueue_struct *ib_wq;
+
 union ib_gid {
 	u8	raw[16];
 	struct {