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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2015-07-17 13:43:18 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2015-10-14 14:32:20 +0200
commit83e9d5d2d45e518deb8cb843bd2e41548c6bb9b2 (patch)
treeb15c94450a4253b4514db6c2cdada6860c3a2437 /drivers/s390/crypto
parent98733791e8ea9f700ce2c6feedcbeb7c4703359e (diff)
s390/zcrypt: fix suspend/resume of AP bus devices
If there are no devices on the AP bus there will not be a single call to the per-device ap_bus_suspend function. Even worse, there will not be a call to the per-device ap_bus_resume either and the AP will fail so resume correctly. Introduce a bus specific dev_pm_ops to suspend / resume the AP bus related things. While we are at it, simplify the power management code of the AP bus. Reviewd-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/crypto')
-rw-r--r--drivers/s390/crypto/ap_bus.c326
1 files changed, 160 insertions, 166 deletions
diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index 80af1bd473e1..8dfd1c9163a7 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -37,6 +37,7 @@
#include <linux/notifier.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
+#include <linux/suspend.h>
#include <asm/reset.h>
#include <asm/airq.h>
#include <linux/atomic.h>
@@ -52,8 +53,6 @@
static void ap_scan_bus(struct work_struct *);
static void ap_poll_all(unsigned long);
static enum hrtimer_restart ap_poll_timeout(struct hrtimer *);
-static int ap_poll_thread_start(void);
-static void ap_poll_thread_stop(void);
static void ap_request_timeout(unsigned long);
static inline void ap_schedule_poll_timer(void);
static int __ap_poll_device(struct ap_device *ap_dev, unsigned long *flags);
@@ -614,6 +613,78 @@ static void ap_decrease_queue_count(struct ap_device *ap_dev)
ap_dev->reset = AP_RESET_IGNORE;
}
+/**
+ * ap_poll_thread(): Thread that polls for finished requests.
+ * @data: Unused pointer
+ *
+ * AP bus poll thread. The purpose of this thread is to poll for
+ * finished requests in a loop if there is a "free" cpu - that is
+ * a cpu that doesn't have anything better to do. The polling stops
+ * as soon as there is another task or if all messages have been
+ * delivered.
+ */
+static int ap_poll_thread(void *data)
+{
+ DECLARE_WAITQUEUE(wait, current);
+ unsigned long flags;
+ struct ap_device *ap_dev;
+
+ set_user_nice(current, MAX_NICE);
+ set_freezable();
+ while (!kthread_should_stop()) {
+ add_wait_queue(&ap_poll_wait, &wait);
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (ap_suspend_flag ||
+ atomic_read(&ap_poll_requests) <= 0) {
+ schedule();
+ try_to_freeze();
+ }
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&ap_poll_wait, &wait);
+
+ if (need_resched()) {
+ schedule();
+ try_to_freeze();
+ continue;
+ }
+
+ flags = 0;
+ spin_lock_bh(&ap_device_list_lock);
+ list_for_each_entry(ap_dev, &ap_device_list, list) {
+ spin_lock(&ap_dev->lock);
+ __ap_poll_device(ap_dev, &flags);
+ spin_unlock(&ap_dev->lock);
+ }
+ spin_unlock_bh(&ap_device_list_lock);
+ } while (!kthread_should_stop());
+ return 0;
+}
+
+static int ap_poll_thread_start(void)
+{
+ int rc;
+
+ if (ap_using_interrupts() || ap_poll_kthread)
+ return 0;
+ mutex_lock(&ap_poll_thread_mutex);
+ ap_poll_kthread = kthread_run(ap_poll_thread, NULL, "appoll");
+ rc = PTR_RET(ap_poll_kthread);
+ if (rc)
+ ap_poll_kthread = NULL;
+ mutex_unlock(&ap_poll_thread_mutex);
+ return rc;
+}
+
+static void ap_poll_thread_stop(void)
+{
+ if (!ap_poll_kthread)
+ return;
+ mutex_lock(&ap_poll_thread_mutex);
+ kthread_stop(ap_poll_kthread);
+ ap_poll_kthread = NULL;
+ mutex_unlock(&ap_poll_thread_mutex);
+}
+
/*
* AP device related attributes.
*/
@@ -827,25 +898,11 @@ static int ap_uevent (struct device *dev, struct kobj_uevent_env *env)
return retval;
}
-static int ap_bus_suspend(struct device *dev, pm_message_t state)
+static int ap_dev_suspend(struct device *dev, pm_message_t state)
{
struct ap_device *ap_dev = to_ap_dev(dev);
unsigned long flags;
- if (!ap_suspend_flag) {
- ap_suspend_flag = 1;
-
- /* Disable scanning for devices, thus we do not want to scan
- * for them after removing.
- */
- del_timer_sync(&ap_config_timer);
- if (ap_work_queue != NULL) {
- destroy_workqueue(ap_work_queue);
- ap_work_queue = NULL;
- }
-
- tasklet_disable(&ap_tasklet);
- }
/* Poll on the device until all requests are finished. */
do {
flags = 0;
@@ -854,72 +911,86 @@ static int ap_bus_suspend(struct device *dev, pm_message_t state)
spin_unlock_bh(&ap_dev->lock);
} while ((flags & 1) || (flags & 2));
- spin_lock_bh(&ap_dev->lock);
- ap_dev->unregistered = 1;
- spin_unlock_bh(&ap_dev->lock);
+ return 0;
+}
+static int ap_dev_resume(struct device *dev)
+{
return 0;
}
-static int ap_bus_resume(struct device *dev)
+static void ap_bus_suspend(void)
+{
+ ap_suspend_flag = 1;
+ /*
+ * Disable scanning for devices, thus we do not want to scan
+ * for them after removing.
+ */
+ del_timer_sync(&ap_config_timer);
+ flush_workqueue(ap_work_queue);
+ tasklet_disable(&ap_tasklet);
+}
+
+static int __ap_devices_unregister(struct device *dev, void *dummy)
+{
+ device_unregister(dev);
+ return 0;
+}
+
+static void ap_bus_resume(void)
{
- struct ap_device *ap_dev = to_ap_dev(dev);
int rc;
- if (ap_suspend_flag) {
- ap_suspend_flag = 0;
- if (ap_interrupts_available()) {
- if (!ap_using_interrupts()) {
- rc = register_adapter_interrupt(&ap_airq);
- ap_airq_flag = (rc == 0);
- }
- } else {
- if (ap_using_interrupts()) {
- unregister_adapter_interrupt(&ap_airq);
- ap_airq_flag = 0;
- }
- }
- ap_query_configuration();
- if (!user_set_domain) {
- ap_domain_index = -1;
- ap_select_domain();
- }
- init_timer(&ap_config_timer);
- ap_config_timer.function = ap_config_timeout;
- ap_config_timer.data = 0;
- ap_config_timer.expires = jiffies + ap_config_time * HZ;
- add_timer(&ap_config_timer);
- ap_work_queue = create_singlethread_workqueue("kapwork");
- if (!ap_work_queue)
- return -ENOMEM;
- tasklet_enable(&ap_tasklet);
- if (!ap_using_interrupts())
- ap_schedule_poll_timer();
- else
- tasklet_schedule(&ap_tasklet);
- if (ap_thread_flag)
- rc = ap_poll_thread_start();
- else
- rc = 0;
- } else
- rc = 0;
- if (AP_QID_QUEUE(ap_dev->qid) != ap_domain_index) {
- spin_lock_bh(&ap_dev->lock);
- ap_dev->qid = AP_MKQID(AP_QID_DEVICE(ap_dev->qid),
- ap_domain_index);
- spin_unlock_bh(&ap_dev->lock);
+ /* Unconditionally remove all AP devices */
+ bus_for_each_dev(&ap_bus_type, NULL, NULL, __ap_devices_unregister);
+ /* Reset thin interrupt setting */
+ if (ap_interrupts_available() && !ap_using_interrupts()) {
+ rc = register_adapter_interrupt(&ap_airq);
+ ap_airq_flag = (rc == 0);
}
+ if (!ap_interrupts_available() && ap_using_interrupts()) {
+ unregister_adapter_interrupt(&ap_airq);
+ ap_airq_flag = 0;
+ }
+ /* Reset domain */
+ if (!user_set_domain)
+ ap_domain_index = -1;
+ /* Get things going again */
+ ap_suspend_flag = 0;
+ if (ap_airq_flag)
+ xchg(ap_airq.lsi_ptr, 0);
+ tasklet_enable(&ap_tasklet);
queue_work(ap_work_queue, &ap_config_work);
+ wake_up(&ap_poll_wait);
+}
- return rc;
+static int ap_power_event(struct notifier_block *this, unsigned long event,
+ void *ptr)
+{
+ switch (event) {
+ case PM_HIBERNATION_PREPARE:
+ case PM_SUSPEND_PREPARE:
+ ap_bus_suspend();
+ break;
+ case PM_POST_HIBERNATION:
+ case PM_POST_SUSPEND:
+ ap_bus_resume();
+ break;
+ default:
+ break;
+ }
+ return NOTIFY_DONE;
}
+static struct notifier_block ap_power_notifier = {
+ .notifier_call = ap_power_event,
+};
static struct bus_type ap_bus_type = {
.name = "ap",
.match = &ap_bus_match,
.uevent = &ap_uevent,
- .suspend = ap_bus_suspend,
- .resume = ap_bus_resume
+ .suspend = ap_dev_suspend,
+ .resume = ap_dev_resume,
};
static int ap_device_probe(struct device *dev)
@@ -1017,6 +1088,8 @@ EXPORT_SYMBOL(ap_driver_unregister);
void ap_bus_force_rescan(void)
{
+ if (ap_suspend_flag)
+ return;
/* reconfigure the AP bus rescan timer. */
mod_timer(&ap_config_timer, jiffies + ap_config_time * HZ);
/* processing a asynchronous bus rescan */
@@ -1102,9 +1175,8 @@ static ssize_t ap_poll_thread_store(struct bus_type *bus,
if (flag) {
rc = ap_poll_thread_start();
if (rc)
- return rc;
- }
- else
+ count = rc;
+ } else
ap_poll_thread_stop();
return count;
}
@@ -1309,7 +1381,8 @@ out:
static void ap_interrupt_handler(struct airq_struct *airq)
{
inc_irq_stat(IRQIO_APB);
- tasklet_schedule(&ap_tasklet);
+ if (!ap_suspend_flag)
+ tasklet_schedule(&ap_tasklet);
}
/**
@@ -1341,9 +1414,8 @@ static void ap_scan_bus(struct work_struct *unused)
int rc, i;
ap_query_configuration();
- if (ap_select_domain() != 0) {
+ if (ap_select_domain() != 0)
return;
- }
for (i = 0; i < AP_DEVICES; i++) {
qid = AP_MKQID(i, ap_domain_index);
@@ -1422,9 +1494,10 @@ static void ap_scan_bus(struct work_struct *unused)
}
}
-static void
-ap_config_timeout(unsigned long ptr)
+static void ap_config_timeout(unsigned long ptr)
{
+ if (ap_suspend_flag)
+ return;
queue_work(ap_work_queue, &ap_config_work);
ap_config_timer.expires = jiffies + ap_config_time * HZ;
add_timer(&ap_config_timer);
@@ -1706,7 +1779,8 @@ EXPORT_SYMBOL(ap_cancel_message);
*/
static enum hrtimer_restart ap_poll_timeout(struct hrtimer *unused)
{
- tasklet_schedule(&ap_tasklet);
+ if (!ap_suspend_flag)
+ tasklet_schedule(&ap_tasklet);
return HRTIMER_NORESTART;
}
@@ -1778,84 +1852,6 @@ static void ap_poll_all(unsigned long dummy)
}
/**
- * ap_poll_thread(): Thread that polls for finished requests.
- * @data: Unused pointer
- *
- * AP bus poll thread. The purpose of this thread is to poll for
- * finished requests in a loop if there is a "free" cpu - that is
- * a cpu that doesn't have anything better to do. The polling stops
- * as soon as there is another task or if all messages have been
- * delivered.
- */
-static int ap_poll_thread(void *data)
-{
- DECLARE_WAITQUEUE(wait, current);
- unsigned long flags;
- int requests;
- struct ap_device *ap_dev;
-
- set_user_nice(current, MAX_NICE);
- while (1) {
- if (ap_suspend_flag)
- return 0;
- if (need_resched()) {
- schedule();
- continue;
- }
- add_wait_queue(&ap_poll_wait, &wait);
- set_current_state(TASK_INTERRUPTIBLE);
- if (kthread_should_stop())
- break;
- requests = atomic_read(&ap_poll_requests);
- if (requests <= 0)
- schedule();
- set_current_state(TASK_RUNNING);
- remove_wait_queue(&ap_poll_wait, &wait);
-
- flags = 0;
- spin_lock_bh(&ap_device_list_lock);
- list_for_each_entry(ap_dev, &ap_device_list, list) {
- spin_lock(&ap_dev->lock);
- __ap_poll_device(ap_dev, &flags);
- spin_unlock(&ap_dev->lock);
- }
- spin_unlock_bh(&ap_device_list_lock);
- }
- set_current_state(TASK_RUNNING);
- remove_wait_queue(&ap_poll_wait, &wait);
- return 0;
-}
-
-static int ap_poll_thread_start(void)
-{
- int rc;
-
- if (ap_using_interrupts() || ap_suspend_flag)
- return 0;
- mutex_lock(&ap_poll_thread_mutex);
- if (!ap_poll_kthread) {
- ap_poll_kthread = kthread_run(ap_poll_thread, NULL, "appoll");
- rc = PTR_RET(ap_poll_kthread);
- if (rc)
- ap_poll_kthread = NULL;
- }
- else
- rc = 0;
- mutex_unlock(&ap_poll_thread_mutex);
- return rc;
-}
-
-static void ap_poll_thread_stop(void)
-{
- mutex_lock(&ap_poll_thread_mutex);
- if (ap_poll_kthread) {
- kthread_stop(ap_poll_kthread);
- ap_poll_kthread = NULL;
- }
- mutex_unlock(&ap_poll_thread_mutex);
-}
-
-/**
* ap_request_timeout(): Handling of request timeouts
* @data: Holds the AP device.
*
@@ -1865,6 +1861,8 @@ static void ap_request_timeout(unsigned long data)
{
struct ap_device *ap_dev = (struct ap_device *) data;
+ if (ap_suspend_flag)
+ return;
if (ap_dev->reset == AP_RESET_ARMED) {
ap_dev->reset = AP_RESET_DO;
@@ -1990,8 +1988,14 @@ int __init ap_module_init(void)
goto out_work;
}
+ rc = register_pm_notifier(&ap_power_notifier);
+ if (rc)
+ goto out_pm;
+
return 0;
+out_pm:
+ ap_poll_thread_stop();
out_work:
del_timer_sync(&ap_config_timer);
hrtimer_cancel(&ap_poll_timer);
@@ -2010,11 +2014,6 @@ out:
return rc;
}
-static int __ap_match_all(struct device *dev, void *data)
-{
- return 1;
-}
-
/**
* ap_modules_exit(): The module termination code
*
@@ -2023,7 +2022,6 @@ static int __ap_match_all(struct device *dev, void *data)
void ap_module_exit(void)
{
int i;
- struct device *dev;
ap_reset_domain();
ap_poll_thread_stop();
@@ -2031,14 +2029,10 @@ void ap_module_exit(void)
hrtimer_cancel(&ap_poll_timer);
destroy_workqueue(ap_work_queue);
tasklet_kill(&ap_tasklet);
- while ((dev = bus_find_device(&ap_bus_type, NULL, NULL,
- __ap_match_all)))
- {
- device_unregister(dev);
- put_device(dev);
- }
+ bus_for_each_dev(&ap_bus_type, NULL, NULL, __ap_devices_unregister);
for (i = 0; ap_bus_attrs[i]; i++)
bus_remove_file(&ap_bus_type, ap_bus_attrs[i]);
+ unregister_pm_notifier(&ap_power_notifier);
root_device_unregister(ap_root_device);
bus_unregister(&ap_bus_type);
kfree(ap_configuration);