Merge branch 'wip-2.6.34' into old-private-masterarchived-private-master

1 files changed, 129 insertions, 23 deletions

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 91c25706fa83..511649115bd7 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -18,6 +18,7 @@
 #include <linux/list.h>
 #include <linux/reboot.h>
 #include <linux/suspend.h>
+#include <linux/proc_fs.h>
 #include <asm/isc.h>
 #include <asm/crw.h>
 
@@ -133,6 +134,8 @@ out:
         return rc;
 }
 
+static void css_sch_todo(struct work_struct *work);
+
 static struct subchannel *
 css_alloc_subchannel(struct subchannel_id schid)
 {
@@ -147,6 +150,7 @@ css_alloc_subchannel(struct subchannel_id schid)
                 kfree(sch);
                 return ERR_PTR(ret);
         }
+        INIT_WORK(&sch->todo_work, css_sch_todo);
         return sch;
 }
 
@@ -190,6 +194,51 @@ void css_sch_device_unregister(struct subchannel *sch)
 }
 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
 
+static void css_sch_todo(struct work_struct *work)
+{
+        struct subchannel *sch;
+        enum sch_todo todo;
+
+        sch = container_of(work, struct subchannel, todo_work);
+        /* Find out todo. */
+        spin_lock_irq(sch->lock);
+        todo = sch->todo;
+        CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
+                      sch->schid.sch_no, todo);
+        sch->todo = SCH_TODO_NOTHING;
+        spin_unlock_irq(sch->lock);
+        /* Perform todo. */
+        if (todo == SCH_TODO_UNREG)
+                css_sch_device_unregister(sch);
+        /* Release workqueue ref. */
+        put_device(&sch->dev);
+}
+
+/**
+ * css_sched_sch_todo - schedule a subchannel operation
+ * @sch: subchannel
+ * @todo: todo
+ *
+ * Schedule the operation identified by @todo to be performed on the slow path
+ * workqueue. Do nothing if another operation with higher priority is already
+ * scheduled. Needs to be called with subchannel lock held.
+ */
+void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
+{
+        CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
+                      sch->schid.ssid, sch->schid.sch_no, todo);
+        if (sch->todo >= todo)
+                return;
+        /* Get workqueue ref. */
+        if (!get_device(&sch->dev))
+                return;
+        sch->todo = todo;
+        if (!queue_work(cio_work_q, &sch->todo_work)) {
+                /* Already queued, release workqueue ref. */
+                put_device(&sch->dev);
+        }
+}
+
 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
 {
         int i;
@@ -376,8 +425,8 @@ static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
                 /* Unusable - ignore. */
                 return 0;
         }
-        CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
-                         "slow path.\n", schid.ssid, schid.sch_no, CIO_OPER);
+        CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid.ssid,
+                      schid.sch_no);
 
         return css_probe_device(schid);
 }
@@ -394,6 +443,10 @@ static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
                                 "Got subchannel machine check but "
                                 "no sch_event handler provided.\n");
         }
+        if (ret != 0 && ret != -EAGAIN) {
+                CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
+                              sch->schid.ssid, sch->schid.sch_no, ret);
+        }
         return ret;
 }
 
@@ -491,7 +544,7 @@ static void css_slow_path_func(struct work_struct *unused)
 }
 
 static DECLARE_WORK(slow_path_work, css_slow_path_func);
-struct workqueue_struct *slow_path_wq;
+struct workqueue_struct *cio_work_q;
 
 void css_schedule_eval(struct subchannel_id schid)
 {
@@ -500,7 +553,7 @@ 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);
+        queue_work(cio_work_q, &slow_path_work);
         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 }
 
@@ -511,7 +564,7 @@ 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);
+        queue_work(cio_work_q, &slow_path_work);
         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 }
 
@@ -542,14 +595,14 @@ void css_schedule_eval_all_unreg(void)
         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);
+        queue_work(cio_work_q, &slow_path_work);
         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
         idset_free(unreg_set);
 }
 
 void css_wait_for_slow_path(void)
 {
-        flush_workqueue(slow_path_wq);
+        flush_workqueue(cio_work_q);
 }
 
 /* Schedule reprobing of all unregistered subchannels. */
@@ -684,6 +737,7 @@ static int __init setup_css(int nr)
         css->pseudo_subchannel->dev.parent = &css->device;
         css->pseudo_subchannel->dev.release = css_subchannel_release;
         dev_set_name(&css->pseudo_subchannel->dev, "defunct");
+        mutex_init(&css->pseudo_subchannel->reg_mutex);
         ret = cio_create_sch_lock(css->pseudo_subchannel);
         if (ret) {
                 kfree(css->pseudo_subchannel);
@@ -816,15 +870,10 @@ static int __init css_bus_init(void)
 
         /* 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:
+        if (ret)
                 max_ssid = 0;
-        }
+        else /* Success. */
+                max_ssid = __MAX_SSID;
 
         ret = slow_subchannel_init();
         if (ret)
@@ -939,12 +988,21 @@ static int __init channel_subsystem_init(void)
         ret = css_bus_init();
         if (ret)
                 return ret;
-
+        cio_work_q = create_singlethread_workqueue("cio");
+        if (!cio_work_q) {
+                ret = -ENOMEM;
+                goto out_bus;
+        }
         ret = io_subchannel_init();
         if (ret)
-                css_bus_cleanup();
+                goto out_wq;
 
         return ret;
+out_wq:
+        destroy_workqueue(cio_work_q);
+out_bus:
+        css_bus_cleanup();
+        return ret;
 }
 subsys_initcall(channel_subsystem_init);
 
@@ -953,10 +1011,25 @@ static int css_settle(struct device_driver *drv, void *unused)
         struct css_driver *cssdrv = to_cssdriver(drv);
 
         if (cssdrv->settle)
-                cssdrv->settle();
+                return cssdrv->settle();
         return 0;
 }
 
+int css_complete_work(void)
+{
+        int ret;
+
+        /* Wait for the evaluation of subchannels to finish. */
+        ret = wait_event_interruptible(css_eval_wq,
+                                       atomic_read(&css_eval_scheduled) == 0);
+        if (ret)
+                return -EINTR;
+        flush_workqueue(cio_work_q);
+        /* Wait for the subchannel type specific initialization to finish */
+        return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
+}
+
+
 /*
  * 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.
@@ -965,13 +1038,46 @@ 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);
+        css_complete_work();
+        return 0;
 }
 subsys_initcall_sync(channel_subsystem_init_sync);
 
+void channel_subsystem_reinit(void)
+{
+        chsc_enable_facility(CHSC_SDA_OC_MSS);
+}
+
+#ifdef CONFIG_PROC_FS
+static ssize_t cio_settle_write(struct file *file, const char __user *buf,
+                                size_t count, loff_t *ppos)
+{
+        int ret;
+
+        /* Handle pending CRW's. */
+        crw_wait_for_channel_report();
+        ret = css_complete_work();
+
+        return ret ? ret : count;
+}
+
+static const struct file_operations cio_settle_proc_fops = {
+        .write = cio_settle_write,
+};
+
+static int __init cio_settle_init(void)
+{
+        struct proc_dir_entry *entry;
+
+        entry = proc_create("cio_settle", S_IWUSR, NULL,
+                            &cio_settle_proc_fops);
+        if (!entry)
+                return -ENOMEM;
+        return 0;
+}
+device_initcall(cio_settle_init);
+#endif /*CONFIG_PROC_FS*/
+
 int sch_is_pseudo_sch(struct subchannel *sch)
 {
         return sch == to_css(sch->dev.parent)->pseudo_subchannel;
@@ -1095,7 +1201,7 @@ static int css_pm_restore(struct device *dev)
         return drv->restore ? drv->restore(sch) : 0;
 }
 
-static struct dev_pm_ops css_pm_ops = {
+static const struct dev_pm_ops css_pm_ops = {
         .prepare = css_pm_prepare,
         .complete = css_pm_complete,
         .freeze = css_pm_freeze,