[S390] pm: css bus power management callbacks

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

4 files changed, 164 insertions, 7 deletions

diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 883f16f96f2..1ecd3e56764 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -549,8 +549,7 @@ cleanup:
         return ret;
 }
 
-static int
-__chsc_do_secm(struct channel_subsystem *css, int enable, void *page)
+int __chsc_do_secm(struct channel_subsystem *css, int enable, void *page)
 {
         struct {
                 struct chsc_header request;
diff --git a/drivers/s390/cio/chsc.h b/drivers/s390/cio/chsc.h
index ba59bceace9..425e8f89a6c 100644
--- a/drivers/s390/cio/chsc.h
+++ b/drivers/s390/cio/chsc.h
@@ -90,6 +90,7 @@ extern void chsc_free_sei_area(void);
 extern int chsc_enable_facility(int);
 struct channel_subsystem;
 extern int chsc_secm(struct channel_subsystem *, int);
+int __chsc_do_secm(struct channel_subsystem *css, int enable, void *page);
 
 int chsc_chp_vary(struct chp_id chpid, int on);
 int chsc_determine_channel_path_desc(struct chp_id chpid, int fmt, int rfmt,
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 0085d890179..85d43c6bcb6 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -1,10 +1,10 @@
 /*
- *  drivers/s390/cio/css.c
- *  driver for channel subsystem
+ * driver for channel subsystem
  *
- *    Copyright IBM Corp. 2002,2008
- *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
- *               Cornelia Huck (cornelia.huck@de.ibm.com)
+ * Copyright IBM Corp. 2002, 2009
+ *
+ * Author(s): Arnd Bergmann (arndb@de.ibm.com)
+ *            Cornelia Huck (cornelia.huck@de.ibm.com)
  */
 
 #define KMSG_COMPONENT "cio"
@@ -17,6 +17,7 @@
 #include <linux/errno.h>
 #include <linux/list.h>
 #include <linux/reboot.h>
+#include <linux/suspend.h>
 #include <asm/isc.h>
 #include <asm/crw.h>
 
@@ -780,6 +781,79 @@ static struct notifier_block css_reboot_notifier = {
 };
 
 /*
+ * Since the css devices are neither on a bus nor have a class
+ * nor have a special device type, we cannot stop/restart channel
+ * path measurements via the normal suspend/resume callbacks, but have
+ * to use notifiers.
+ */
+static int css_power_event(struct notifier_block *this, unsigned long event,
+                           void *ptr)
+{
+        void *secm_area;
+        int ret, i;
+
+        switch (event) {
+        case PM_HIBERNATION_PREPARE:
+        case PM_SUSPEND_PREPARE:
+                ret = NOTIFY_DONE;
+                for (i = 0; i <= __MAX_CSSID; i++) {
+                        struct channel_subsystem *css;
+
+                        css = channel_subsystems[i];
+                        mutex_lock(&css->mutex);
+                        if (!css->cm_enabled) {
+                                mutex_unlock(&css->mutex);
+                                continue;
+                        }
+                        secm_area = (void *)get_zeroed_page(GFP_KERNEL |
+                                                            GFP_DMA);
+                        if (secm_area) {
+                                if (__chsc_do_secm(css, 0, secm_area))
+                                        ret = NOTIFY_BAD;
+                                free_page((unsigned long)secm_area);
+                        } else
+                                ret = NOTIFY_BAD;
+
+                        mutex_unlock(&css->mutex);
+                }
+                break;
+        case PM_POST_HIBERNATION:
+        case PM_POST_SUSPEND:
+                ret = NOTIFY_DONE;
+                for (i = 0; i <= __MAX_CSSID; i++) {
+                        struct channel_subsystem *css;
+
+                        css = channel_subsystems[i];
+                        mutex_lock(&css->mutex);
+                        if (!css->cm_enabled) {
+                                mutex_unlock(&css->mutex);
+                                continue;
+                        }
+                        secm_area = (void *)get_zeroed_page(GFP_KERNEL |
+                                                            GFP_DMA);
+                        if (secm_area) {
+                                if (__chsc_do_secm(css, 1, secm_area))
+                                        ret = NOTIFY_BAD;
+                                free_page((unsigned long)secm_area);
+                        } else
+                                ret = NOTIFY_BAD;
+
+                        mutex_unlock(&css->mutex);
+                }
+                /* search for subchannels, which appeared during hibernation */
+                css_schedule_reprobe();
+                break;
+        default:
+                ret = NOTIFY_DONE;
+        }
+        return ret;
+
+}
+static struct notifier_block css_power_notifier = {
+        .notifier_call = css_power_event,
+};
+
+/*
  * Now that the driver core is running, we can setup our channel subsystem.
  * The struct subchannel's are created during probing (except for the
  * static console subchannel).
@@ -852,6 +926,11 @@ init_channel_subsystem (void)
         ret = register_reboot_notifier(&css_reboot_notifier);
         if (ret)
                 goto out_unregister;
+        ret = register_pm_notifier(&css_power_notifier);
+        if (ret) {
+                unregister_reboot_notifier(&css_reboot_notifier);
+                goto out_unregister;
+        }
         css_init_done = 1;
 
         /* Enable default isc for I/O subchannels. */
@@ -953,6 +1032,73 @@ static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
         return ret;
 }
 
+static int css_pm_prepare(struct device *dev)
+{
+        struct subchannel *sch = to_subchannel(dev);
+        struct css_driver *drv;
+
+        if (mutex_is_locked(&sch->reg_mutex))
+                return -EAGAIN;
+        if (!sch->dev.driver)
+                return 0;
+        drv = to_cssdriver(sch->dev.driver);
+        /* Notify drivers that they may not register children. */
+        return drv->prepare ? drv->prepare(sch) : 0;
+}
+
+static void css_pm_complete(struct device *dev)
+{
+        struct subchannel *sch = to_subchannel(dev);
+        struct css_driver *drv;
+
+        if (!sch->dev.driver)
+                return;
+        drv = to_cssdriver(sch->dev.driver);
+        if (drv->complete)
+                drv->complete(sch);
+}
+
+static int css_pm_freeze(struct device *dev)
+{
+        struct subchannel *sch = to_subchannel(dev);
+        struct css_driver *drv;
+
+        if (!sch->dev.driver)
+                return 0;
+        drv = to_cssdriver(sch->dev.driver);
+        return drv->freeze ? drv->freeze(sch) : 0;
+}
+
+static int css_pm_thaw(struct device *dev)
+{
+        struct subchannel *sch = to_subchannel(dev);
+        struct css_driver *drv;
+
+        if (!sch->dev.driver)
+                return 0;
+        drv = to_cssdriver(sch->dev.driver);
+        return drv->thaw ? drv->thaw(sch) : 0;
+}
+
+static int css_pm_restore(struct device *dev)
+{
+        struct subchannel *sch = to_subchannel(dev);
+        struct css_driver *drv;
+
+        if (!sch->dev.driver)
+                return 0;
+        drv = to_cssdriver(sch->dev.driver);
+        return drv->restore ? drv->restore(sch) : 0;
+}
+
+static struct dev_pm_ops css_pm_ops = {
+        .prepare = css_pm_prepare,
+        .complete = css_pm_complete,
+        .freeze = css_pm_freeze,
+        .thaw = css_pm_thaw,
+        .restore = css_pm_restore,
+};
+
 struct bus_type css_bus_type = {
         .name     = "css",
         .match    = css_bus_match,
@@ -960,6 +1106,7 @@ struct bus_type css_bus_type = {
         .remove   = css_remove,
         .shutdown = css_shutdown,
         .uevent   = css_uevent,
+        .pm = &css_pm_ops,
 };
 
 /**
diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h
index 57ebf120f82..9763eeec745 100644
--- a/drivers/s390/cio/css.h
+++ b/drivers/s390/cio/css.h
@@ -70,6 +70,11 @@ struct chp_link;
  * @probe: function called on probe
  * @remove: function called on remove
  * @shutdown: called at device shutdown
+ * @prepare: prepare for pm state transition
+ * @complete: undo work done in @prepare
+ * @freeze: callback for freezing during hibernation snapshotting
+ * @thaw: undo work done in @freeze
+ * @restore: callback for restoring after hibernation
  * @name: name of the device driver
  */
 struct css_driver {
@@ -82,6 +87,11 @@ struct css_driver {
         int (*probe)(struct subchannel *);
         int (*remove)(struct subchannel *);
         void (*shutdown)(struct subchannel *);
+        int (*prepare) (struct subchannel *);
+        void (*complete) (struct subchannel *);
+        int (*freeze)(struct subchannel *);
+        int (*thaw) (struct subchannel *);
+        int (*restore)(struct subchannel *);
         const char *name;
 };