EDAC: Rework workqueue handling

Hide the EDAC workqueue pointer in a separate compilation unit and add
accessors for the workqueue manipulations needed.

Remove edac_pci_reset_delay_period() which wasn't used by anything. It
seems it got added without a user with

  91b99041c1d5 ("drivers/edac: updated PCI monitoring")

Signed-off-by: Borislav Petkov <bp@suse.de>

drivers/edac/Makefile

@@ -10,7 +10,7 @@ obj-$(CONFIG_EDAC)			:= edac_stub.o
 obj-$(CONFIG_EDAC_MM_EDAC)		+= edac_core.o
 
 edac_core-y	:= edac_mc.o edac_device.o edac_mc_sysfs.o
-edac_core-y	+= edac_module.o edac_device_sysfs.o
+edac_core-y	+= edac_module.o edac_device_sysfs.o wq.o
 
 edac_core-$(CONFIG_EDAC_DEBUG)		+= debugfs.o
 

drivers/edac/edac_device.c

@@ -390,11 +390,9 @@ static void edac_device_workq_function(struct work_struct *work_req)
 	 * between integral seconds
 	 */
 	if (edac_dev->poll_msec == 1000)
-		queue_delayed_work(edac_workqueue, &edac_dev->work,
-				round_jiffies_relative(edac_dev->delay));
+		edac_queue_work(&edac_dev->work, round_jiffies_relative(edac_dev->delay));
 	else
-		queue_delayed_work(edac_workqueue, &edac_dev->work,
-				edac_dev->delay);
+		edac_queue_work(&edac_dev->work, edac_dev->delay);
 }
 
 /*
@@ -422,11 +420,9 @@ static void edac_device_workq_setup(struct edac_device_ctl_info *edac_dev,
 	 * to fire together on the 1 second exactly
 	 */
 	if (edac_dev->poll_msec == 1000)
-		queue_delayed_work(edac_workqueue, &edac_dev->work,
-				round_jiffies_relative(edac_dev->delay));
+		edac_queue_work(&edac_dev->work, round_jiffies_relative(edac_dev->delay));
 	else
-		queue_delayed_work(edac_workqueue, &edac_dev->work,
-				edac_dev->delay);
+		edac_queue_work(&edac_dev->work, edac_dev->delay);
 }
 
 /*
@@ -440,8 +436,7 @@ static void edac_device_workq_teardown(struct edac_device_ctl_info *edac_dev)
 
 	edac_dev->op_state = OP_OFFLINE;
 
-	cancel_delayed_work_sync(&edac_dev->work);
-	flush_workqueue(edac_workqueue);
+	edac_stop_work(&edac_dev->work);
 }
 
 /*
@@ -454,16 +449,15 @@ static void edac_device_workq_teardown(struct edac_device_ctl_info *edac_dev)
 void edac_device_reset_delay_period(struct edac_device_ctl_info *edac_dev,
 					unsigned long value)
 {
-	/* cancel the current workq request, without the mutex lock */
-	edac_device_workq_teardown(edac_dev);
+	unsigned long jiffs = msecs_to_jiffies(value);
 
-	/* acquire the mutex before doing the workq setup */
-	mutex_lock(&device_ctls_mutex);
+	if (value == 1000)
+		jiffs = round_jiffies_relative(value);
 
-	/* restart the workq request, with new delay value */
-	edac_device_workq_setup(edac_dev, value);
+	edac_dev->poll_msec = value;
+	edac_dev->delay	    = jiffs;
 
-	mutex_unlock(&device_ctls_mutex);
+	edac_mod_work(&edac_dev->work, jiffs);
 }
 
 /*

drivers/edac/edac_mc.c

@@ -548,8 +548,7 @@ static void edac_mc_workq_function(struct work_struct *work_req)
 	mutex_unlock(&mem_ctls_mutex);
 
 	/* Reschedule */
-	queue_delayed_work(edac_workqueue, &mci->work,
-			msecs_to_jiffies(edac_mc_get_poll_msec()));
+	edac_queue_work(&mci->work, msecs_to_jiffies(edac_mc_get_poll_msec()));
 }
 
 /*
@@ -561,8 +560,7 @@ static void edac_mc_workq_function(struct work_struct *work_req)
  *
  *		called with the mem_ctls_mutex held
  */
-static void edac_mc_workq_setup(struct mem_ctl_info *mci, unsigned msec,
-				bool init)
+static void edac_mc_workq_setup(struct mem_ctl_info *mci, unsigned msec)
 {
 	edac_dbg(0, "\n");
 
@@ -570,10 +568,9 @@ static void edac_mc_workq_setup(struct mem_ctl_info *mci, unsigned msec,
 	if (mci->op_state != OP_RUNNING_POLL)
 		return;
 
-	if (init)
-		INIT_DELAYED_WORK(&mci->work, edac_mc_workq_function);
+	INIT_DELAYED_WORK(&mci->work, edac_mc_workq_function);
 
-	mod_delayed_work(edac_workqueue, &mci->work, msecs_to_jiffies(msec));
+	edac_queue_work(&mci->work, msecs_to_jiffies(msec));
 }
 
 /*
@@ -588,8 +585,7 @@ static void edac_mc_workq_teardown(struct mem_ctl_info *mci)
 {
 	mci->op_state = OP_OFFLINE;
 
-	cancel_delayed_work_sync(&mci->work);
-	flush_workqueue(edac_workqueue);
+	edac_stop_work(&mci->work);
 }
 
 /*
@@ -608,9 +604,8 @@ void edac_mc_reset_delay_period(unsigned long value)
 	list_for_each(item, &mc_devices) {
 		mci = list_entry(item, struct mem_ctl_info, link);
 
-		edac_mc_workq_setup(mci, value, false);
+		edac_mod_work(&mci->work, value);
 	}
-
 	mutex_unlock(&mem_ctls_mutex);
 }
 
@@ -781,7 +776,7 @@ int edac_mc_add_mc_with_groups(struct mem_ctl_info *mci,
 		/* This instance is NOW RUNNING */
 		mci->op_state = OP_RUNNING_POLL;
 
-		edac_mc_workq_setup(mci, edac_mc_get_poll_msec(), true);
+		edac_mc_workq_setup(mci, edac_mc_get_poll_msec());
 	} else {
 		mci->op_state = OP_RUNNING_INTERRUPT;
 	}

drivers/edac/edac_module.c

@@ -43,9 +43,6 @@ module_param_call(edac_debug_level, edac_set_debug_level, param_get_int,
 MODULE_PARM_DESC(edac_debug_level, "EDAC debug level: [0-4], default: 2");
 #endif
 
-/* scope is to module level only */
-struct workqueue_struct *edac_workqueue;
-
 /*
  * edac_op_state_to_string()
  */
@@ -65,32 +62,6 @@ char *edac_op_state_to_string(int opstate)
 	return "UNKNOWN";
 }
 
-/*
- * edac_workqueue_setup
- *	initialize the edac work queue for polling operations
- */
-static int edac_workqueue_setup(void)
-{
-	edac_workqueue = create_singlethread_workqueue("edac-poller");
-	if (edac_workqueue == NULL)
-		return -ENODEV;
-	else
-		return 0;
-}
-
-/*
- * edac_workqueue_teardown
- *	teardown the edac workqueue
- */
-static void edac_workqueue_teardown(void)
-{
-	if (edac_workqueue) {
-		flush_workqueue(edac_workqueue);
-		destroy_workqueue(edac_workqueue);
-		edac_workqueue = NULL;
-	}
-}
-
 /*
  * sysfs object: /sys/devices/system/edac
  *	need to export to other files

drivers/edac/edac_module.h

@@ -47,7 +47,12 @@ extern int edac_device_create_sysfs(struct edac_device_ctl_info *edac_dev);
 extern void edac_device_remove_sysfs(struct edac_device_ctl_info *edac_dev);
 
 /* edac core workqueue: single CPU mode */
-extern struct workqueue_struct *edac_workqueue;
+int edac_workqueue_setup(void);
+void edac_workqueue_teardown(void);
+bool edac_queue_work(struct delayed_work *work, unsigned long delay);
+bool edac_stop_work(struct delayed_work *work);
+bool edac_mod_work(struct delayed_work *work, unsigned long delay);
+
 extern void edac_device_reset_delay_period(struct edac_device_ctl_info
 					   *edac_dev, unsigned long value);
 extern void edac_mc_reset_delay_period(unsigned long value);

drivers/edac/edac_pci.c

@@ -209,7 +209,7 @@ static void edac_pci_workq_function(struct work_struct *work_req)
 			delay = msecs_to_jiffies(msec);
 
 		/* Reschedule only if we are in POLL mode */
-		queue_delayed_work(edac_workqueue, &pci->work, delay);
+		edac_queue_work(&pci->work, delay);
 	}
 
 	mutex_unlock(&edac_pci_ctls_mutex);
@@ -229,8 +229,8 @@ static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
 	edac_dbg(0, "\n");
 
 	INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
-	queue_delayed_work(edac_workqueue, &pci->work,
-			msecs_to_jiffies(edac_pci_get_poll_msec()));
+
+	edac_queue_work(&pci->work, msecs_to_jiffies(edac_pci_get_poll_msec()));
 }
 
 /*
@@ -243,32 +243,8 @@ static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
 
 	pci->op_state = OP_OFFLINE;
 
-	cancel_delayed_work_sync(&pci->work);
-	flush_workqueue(edac_workqueue);
-}
-
-/*
- * edac_pci_reset_delay_period
- *
- *	called with a new period value for the workq period
- *	a) stop current workq timer
- *	b) restart workq timer with new value
- */
-void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci,
-				 unsigned long value)
-{
-	edac_dbg(0, "\n");
-
-	edac_pci_workq_teardown(pci);
-
-	/* need to lock for the setup */
-	mutex_lock(&edac_pci_ctls_mutex);
-
-	edac_pci_workq_setup(pci, value);
-
-	mutex_unlock(&edac_pci_ctls_mutex);
+	edac_stop_work(&pci->work);
 }
-EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period);
 
 /*
  * edac_pci_alloc_index: Allocate a unique PCI index number

drivers/edac/wq.c

@@ -0,0 +1,42 @@
+#include "edac_module.h"
+
+static struct workqueue_struct *wq;
+
+bool edac_queue_work(struct delayed_work *work, unsigned long delay)
+{
+	return queue_delayed_work(wq, work, delay);
+}
+EXPORT_SYMBOL_GPL(edac_queue_work);
+
+bool edac_mod_work(struct delayed_work *work, unsigned long delay)
+{
+	return mod_delayed_work(wq, work, delay);
+}
+EXPORT_SYMBOL_GPL(edac_mod_work);
+
+bool edac_stop_work(struct delayed_work *work)
+{
+	bool ret;
+
+	ret = cancel_delayed_work_sync(work);
+	flush_workqueue(wq);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(edac_stop_work);
+
+int edac_workqueue_setup(void)
+{
+	wq = create_singlethread_workqueue("edac-poller");
+	if (!wq)
+		return -ENODEV;
+	else
+		return 0;
+}
+
+void edac_workqueue_teardown(void)
+{
+	flush_workqueue(wq);
+	destroy_workqueue(wq);
+	wq = NULL;
+}