1 files changed, 128 insertions, 124 deletions

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 393c73c47f87..91c25706fa83 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -31,8 +31,7 @@
 #include "chp.h"
 
 int css_init_done = 0;
-static int need_reprobe = 0;
-static int max_ssid = 0;
+int max_ssid;
 
 struct channel_subsystem *channel_subsystems[__MAX_CSSID + 1];
 
@@ -315,12 +314,18 @@ int css_probe_device(struct subchannel_id schid)
 	int ret;
 	struct subchannel *sch;
 
-	sch = css_alloc_subchannel(schid);
-	if (IS_ERR(sch))
-		return PTR_ERR(sch);
+	if (cio_is_console(schid))
+		sch = cio_get_console_subchannel();
+	else {
+		sch = css_alloc_subchannel(schid);
+		if (IS_ERR(sch))
+			return PTR_ERR(sch);
+	}
 	ret = css_register_subchannel(sch);
-	if (ret)
-		put_device(&sch->dev);
+	if (ret) {
+		if (!cio_is_console(schid))
+			put_device(&sch->dev);
+	}
 	return ret;
 }
 
@@ -409,10 +414,14 @@ static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
 
 static struct idset *slow_subchannel_set;
 static spinlock_t slow_subchannel_lock;
+static wait_queue_head_t css_eval_wq;
+static atomic_t css_eval_scheduled;
 
 static int __init slow_subchannel_init(void)
 {
 	spin_lock_init(&slow_subchannel_lock);
+	atomic_set(&css_eval_scheduled, 0);
+	init_waitqueue_head(&css_eval_wq);
 	slow_subchannel_set = idset_sch_new();
 	if (!slow_subchannel_set) {
 		CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
@@ -468,9 +477,17 @@ static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
 
 static void css_slow_path_func(struct work_struct *unused)
 {
+	unsigned long flags;
+
 	CIO_TRACE_EVENT(4, "slowpath");
 	for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
 				   NULL);
+	spin_lock_irqsave(&slow_subchannel_lock, flags);
+	if (idset_is_empty(slow_subchannel_set)) {
+		atomic_set(&css_eval_scheduled, 0);
+		wake_up(&css_eval_wq);
+	}
+	spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 }
 
 static DECLARE_WORK(slow_path_work, css_slow_path_func);
@@ -482,6 +499,7 @@ void css_schedule_eval(struct subchannel_id schid)
 
 	spin_lock_irqsave(&slow_subchannel_lock, flags);
 	idset_sch_add(slow_subchannel_set, schid);
+	atomic_set(&css_eval_scheduled, 1);
 	queue_work(slow_path_wq, &slow_path_work);
 	spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 }
@@ -492,80 +510,53 @@ void css_schedule_eval_all(void)
 
 	spin_lock_irqsave(&slow_subchannel_lock, flags);
 	idset_fill(slow_subchannel_set);
+	atomic_set(&css_eval_scheduled, 1);
 	queue_work(slow_path_wq, &slow_path_work);
 	spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 }
 
-void css_wait_for_slow_path(void)
+static int __unset_registered(struct device *dev, void *data)
 {
-	flush_workqueue(slow_path_wq);
-}
-
-/* Reprobe subchannel if unregistered. */
-static int reprobe_subchannel(struct subchannel_id schid, void *data)
-{
-	int ret;
-
-	CIO_MSG_EVENT(6, "cio: reprobe 0.%x.%04x\n",
-		      schid.ssid, schid.sch_no);
-	if (need_reprobe)
-		return -EAGAIN;
-
-	ret = css_probe_device(schid);
-	switch (ret) {
-	case 0:
-		break;
-	case -ENXIO:
-	case -ENOMEM:
-	case -EIO:
-		/* These should abort looping */
-		break;
-	default:
-		ret = 0;
-	}
-
-	return ret;
-}
+	struct idset *set = data;
+	struct subchannel *sch = to_subchannel(dev);
 
-static void reprobe_after_idle(struct work_struct *unused)
-{
-	/* Make sure initial subchannel scan is done. */
-	wait_event(ccw_device_init_wq,
-		   atomic_read(&ccw_device_init_count) == 0);
-	if (need_reprobe)
-		css_schedule_reprobe();
+	idset_sch_del(set, sch->schid);
+	return 0;
 }
 
-static DECLARE_WORK(reprobe_idle_work, reprobe_after_idle);
-
-/* Work function used to reprobe all unregistered subchannels. */
-static void reprobe_all(struct work_struct *unused)
+void css_schedule_eval_all_unreg(void)
 {
-	int ret;
-
-	CIO_MSG_EVENT(4, "reprobe start\n");
+	unsigned long flags;
+	struct idset *unreg_set;
 
-	/* Make sure initial subchannel scan is done. */
-	if (atomic_read(&ccw_device_init_count) != 0) {
-		queue_work(ccw_device_work, &reprobe_idle_work);
+	/* Find unregistered subchannels. */
+	unreg_set = idset_sch_new();
+	if (!unreg_set) {
+		/* Fallback. */
+		css_schedule_eval_all();
 		return;
 	}
-	need_reprobe = 0;
-	ret = for_each_subchannel_staged(NULL, reprobe_subchannel, NULL);
-
-	CIO_MSG_EVENT(4, "reprobe done (rc=%d, need_reprobe=%d)\n", ret,
-		      need_reprobe);
+	idset_fill(unreg_set);
+	bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered);
+	/* Apply to slow_subchannel_set. */
+	spin_lock_irqsave(&slow_subchannel_lock, flags);
+	idset_add_set(slow_subchannel_set, unreg_set);
+	atomic_set(&css_eval_scheduled, 1);
+	queue_work(slow_path_wq, &slow_path_work);
+	spin_unlock_irqrestore(&slow_subchannel_lock, flags);
+	idset_free(unreg_set);
 }
 
-static DECLARE_WORK(css_reprobe_work, reprobe_all);
+void css_wait_for_slow_path(void)
+{
+	flush_workqueue(slow_path_wq);
+}
 
 /* Schedule reprobing of all unregistered subchannels. */
 void css_schedule_reprobe(void)
 {
-	need_reprobe = 1;
-	queue_work(slow_path_wq, &css_reprobe_work);
+	css_schedule_eval_all_unreg();
 }
-
 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
 
 /*
@@ -601,49 +592,6 @@ static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
 	css_evaluate_subchannel(mchk_schid, 0);
 }
 
-static int __init
-__init_channel_subsystem(struct subchannel_id schid, void *data)
-{
-	struct subchannel *sch;
-	int ret;
-
-	if (cio_is_console(schid))
-		sch = cio_get_console_subchannel();
-	else {
-		sch = css_alloc_subchannel(schid);
-		if (IS_ERR(sch))
-			ret = PTR_ERR(sch);
-		else
-			ret = 0;
-		switch (ret) {
-		case 0:
-			break;
-		case -ENOMEM:
-			panic("Out of memory in init_channel_subsystem\n");
-		/* -ENXIO: no more subchannels. */
-		case -ENXIO:
-			return ret;
-		/* -EIO: this subchannel set not supported. */
-		case -EIO:
-			return ret;
-		default:
-			return 0;
-		}
-	}
-	/*
-	 * We register ALL valid subchannels in ioinfo, even those
-	 * that have been present before init_channel_subsystem.
-	 * These subchannels can't have been registered yet (kmalloc
-	 * not working) so we do it now. This is true e.g. for the
-	 * console subchannel.
-	 */
-	if (css_register_subchannel(sch)) {
-		if (!cio_is_console(schid))
-			put_device(&sch->dev);
-	}
-	return 0;
-}
-
 static void __init
 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
 {
@@ -854,19 +802,30 @@ static struct notifier_block css_power_notifier = {
  * The struct subchannel's are created during probing (except for the
  * static console subchannel).
  */
-static int __init
-init_channel_subsystem (void)
+static int __init css_bus_init(void)
 {
 	int ret, i;
 
 	ret = chsc_determine_css_characteristics();
 	if (ret == -ENOMEM)
-		goto out; /* No need to continue. */
+		goto out;
 
 	ret = chsc_alloc_sei_area();
 	if (ret)
 		goto out;
 
+	/* Try to enable MSS. */
+	ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
+	switch (ret) {
+	case 0: /* Success. */
+		max_ssid = __MAX_SSID;
+		break;
+	case -ENOMEM:
+		goto out;
+	default:
+		max_ssid = 0;
+	}
+
 	ret = slow_subchannel_init();
 	if (ret)
 		goto out;
@@ -878,17 +837,6 @@ init_channel_subsystem (void)
 	if ((ret = bus_register(&css_bus_type)))
 		goto out;
 
-	/* Try to enable MSS. */
-	ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
-	switch (ret) {
-	case 0: /* Success. */
-		max_ssid = __MAX_SSID;
-		break;
-	case -ENOMEM:
-		goto out_bus;
-	default:
-		max_ssid = 0;
-	}
 	/* Setup css structure. */
 	for (i = 0; i <= __MAX_CSSID; i++) {
 		struct channel_subsystem *css;
@@ -934,7 +882,6 @@ init_channel_subsystem (void)
 	/* Enable default isc for I/O subchannels. */
 	isc_register(IO_SCH_ISC);
 
-	for_each_subchannel(__init_channel_subsystem, NULL);
 	return 0;
 out_file:
 	if (css_chsc_characteristics.secm)
@@ -955,17 +902,76 @@ out_unregister:
 					   &dev_attr_cm_enable);
 		device_unregister(&css->device);
 	}
-out_bus:
 	bus_unregister(&css_bus_type);
 out:
 	crw_unregister_handler(CRW_RSC_CSS);
 	chsc_free_sei_area();
-	kfree(slow_subchannel_set);
+	idset_free(slow_subchannel_set);
 	pr_alert("The CSS device driver initialization failed with "
 		 "errno=%d\n", ret);
 	return ret;
 }
 
+static void __init css_bus_cleanup(void)
+{
+	struct channel_subsystem *css;
+	int i;
+
+	for (i = 0; i <= __MAX_CSSID; i++) {
+		css = channel_subsystems[i];
+		device_unregister(&css->pseudo_subchannel->dev);
+		css->pseudo_subchannel = NULL;
+		if (css_chsc_characteristics.secm)
+			device_remove_file(&css->device, &dev_attr_cm_enable);
+		device_unregister(&css->device);
+	}
+	bus_unregister(&css_bus_type);
+	crw_unregister_handler(CRW_RSC_CSS);
+	chsc_free_sei_area();
+	idset_free(slow_subchannel_set);
+	isc_unregister(IO_SCH_ISC);
+}
+
+static int __init channel_subsystem_init(void)
+{
+	int ret;
+
+	ret = css_bus_init();
+	if (ret)
+		return ret;
+
+	ret = io_subchannel_init();
+	if (ret)
+		css_bus_cleanup();
+
+	return ret;
+}
+subsys_initcall(channel_subsystem_init);
+
+static int css_settle(struct device_driver *drv, void *unused)
+{
+	struct css_driver *cssdrv = to_cssdriver(drv);
+
+	if (cssdrv->settle)
+		cssdrv->settle();
+	return 0;
+}
+
+/*
+ * Wait for the initialization of devices to finish, to make sure we are
+ * done with our setup if the search for the root device starts.
+ */
+static int __init channel_subsystem_init_sync(void)
+{
+	/* Start initial subchannel evaluation. */
+	css_schedule_eval_all();
+	/* Wait for the evaluation of subchannels to finish. */
+	wait_event(css_eval_wq, atomic_read(&css_eval_scheduled) == 0);
+	/* Wait for the subchannel type specific initialization to finish */
+	return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
+}
+subsys_initcall_sync(channel_subsystem_init_sync);
+
 int sch_is_pseudo_sch(struct subchannel *sch)
 {
 	return sch == to_css(sch->dev.parent)->pseudo_subchannel;
@@ -1135,7 +1141,5 @@ void css_driver_unregister(struct css_driver *cdrv)
 }
 EXPORT_SYMBOL_GPL(css_driver_unregister);
 
-subsys_initcall(init_channel_subsystem);
-
 MODULE_LICENSE("GPL");
 EXPORT_SYMBOL(css_bus_type);