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Diffstat (limited to 'drivers/s390/char/sclp.c')
-rw-r--r--drivers/s390/char/sclp.c248
1 files changed, 218 insertions, 30 deletions
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index 4377e93a43d7..a983f5086788 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -1,11 +1,10 @@
/*
- * drivers/s390/char/sclp.c
- * core function to access sclp interface
+ * core function to access sclp interface
*
- * S390 version
- * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
- * Author(s): Martin Peschke <mpeschke@de.ibm.com>
- * Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2009
+ *
+ * Author(s): Martin Peschke <mpeschke@de.ibm.com>
+ * Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
#include <linux/module.h>
@@ -16,6 +15,9 @@
#include <linux/reboot.h>
#include <linux/jiffies.h>
#include <linux/init.h>
+#include <linux/suspend.h>
+#include <linux/completion.h>
+#include <linux/platform_device.h>
#include <asm/types.h>
#include <asm/s390_ext.h>
@@ -47,6 +49,16 @@ static struct sclp_req sclp_init_req;
static char sclp_read_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
static char sclp_init_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+/* Suspend request */
+static DECLARE_COMPLETION(sclp_request_queue_flushed);
+
+static void sclp_suspend_req_cb(struct sclp_req *req, void *data)
+{
+ complete(&sclp_request_queue_flushed);
+}
+
+static struct sclp_req sclp_suspend_req;
+
/* Timer for request retries. */
static struct timer_list sclp_request_timer;
@@ -84,6 +96,12 @@ static volatile enum sclp_mask_state_t {
sclp_mask_state_initializing
} sclp_mask_state = sclp_mask_state_idle;
+/* Internal state: is the driver suspended? */
+static enum sclp_suspend_state_t {
+ sclp_suspend_state_running,
+ sclp_suspend_state_suspended,
+} sclp_suspend_state = sclp_suspend_state_running;
+
/* Maximum retry counts */
#define SCLP_INIT_RETRY 3
#define SCLP_MASK_RETRY 3
@@ -211,6 +229,8 @@ sclp_process_queue(void)
del_timer(&sclp_request_timer);
while (!list_empty(&sclp_req_queue)) {
req = list_entry(sclp_req_queue.next, struct sclp_req, list);
+ if (!req->sccb)
+ goto do_post;
rc = __sclp_start_request(req);
if (rc == 0)
break;
@@ -222,6 +242,7 @@ sclp_process_queue(void)
sclp_request_timeout, 0);
break;
}
+do_post:
/* Post-processing for aborted request */
list_del(&req->list);
if (req->callback) {
@@ -233,6 +254,19 @@ sclp_process_queue(void)
spin_unlock_irqrestore(&sclp_lock, flags);
}
+static int __sclp_can_add_request(struct sclp_req *req)
+{
+ if (req == &sclp_suspend_req || req == &sclp_init_req)
+ return 1;
+ if (sclp_suspend_state != sclp_suspend_state_running)
+ return 0;
+ if (sclp_init_state != sclp_init_state_initialized)
+ return 0;
+ if (sclp_activation_state != sclp_activation_state_active)
+ return 0;
+ return 1;
+}
+
/* Queue a new request. Return zero on success, non-zero otherwise. */
int
sclp_add_request(struct sclp_req *req)
@@ -241,9 +275,7 @@ sclp_add_request(struct sclp_req *req)
int rc;
spin_lock_irqsave(&sclp_lock, flags);
- if ((sclp_init_state != sclp_init_state_initialized ||
- sclp_activation_state != sclp_activation_state_active) &&
- req != &sclp_init_req) {
+ if (!__sclp_can_add_request(req)) {
spin_unlock_irqrestore(&sclp_lock, flags);
return -EIO;
}
@@ -254,10 +286,16 @@ sclp_add_request(struct sclp_req *req)
/* Start if request is first in list */
if (sclp_running_state == sclp_running_state_idle &&
req->list.prev == &sclp_req_queue) {
+ if (!req->sccb) {
+ list_del(&req->list);
+ rc = -ENODATA;
+ goto out;
+ }
rc = __sclp_start_request(req);
if (rc)
list_del(&req->list);
}
+out:
spin_unlock_irqrestore(&sclp_lock, flags);
return rc;
}
@@ -560,6 +598,7 @@ sclp_register(struct sclp_register *reg)
/* Trigger initial state change callback */
reg->sclp_receive_mask = 0;
reg->sclp_send_mask = 0;
+ reg->pm_event_posted = 0;
list_add(&reg->list, &sclp_reg_list);
spin_unlock_irqrestore(&sclp_lock, flags);
rc = sclp_init_mask(1);
@@ -880,20 +919,134 @@ static struct notifier_block sclp_reboot_notifier = {
.notifier_call = sclp_reboot_event
};
+/*
+ * Suspend/resume SCLP notifier implementation
+ */
+
+static void sclp_pm_event(enum sclp_pm_event sclp_pm_event, int rollback)
+{
+ struct sclp_register *reg;
+ unsigned long flags;
+
+ if (!rollback) {
+ spin_lock_irqsave(&sclp_lock, flags);
+ list_for_each_entry(reg, &sclp_reg_list, list)
+ reg->pm_event_posted = 0;
+ spin_unlock_irqrestore(&sclp_lock, flags);
+ }
+ do {
+ spin_lock_irqsave(&sclp_lock, flags);
+ list_for_each_entry(reg, &sclp_reg_list, list) {
+ if (rollback && reg->pm_event_posted)
+ goto found;
+ if (!rollback && !reg->pm_event_posted)
+ goto found;
+ }
+ spin_unlock_irqrestore(&sclp_lock, flags);
+ return;
+found:
+ spin_unlock_irqrestore(&sclp_lock, flags);
+ if (reg->pm_event_fn)
+ reg->pm_event_fn(reg, sclp_pm_event);
+ reg->pm_event_posted = rollback ? 0 : 1;
+ } while (1);
+}
+
+/*
+ * Susend/resume callbacks for platform device
+ */
+
+static int sclp_freeze(struct device *dev)
+{
+ unsigned long flags;
+ int rc;
+
+ sclp_pm_event(SCLP_PM_EVENT_FREEZE, 0);
+
+ spin_lock_irqsave(&sclp_lock, flags);
+ sclp_suspend_state = sclp_suspend_state_suspended;
+ spin_unlock_irqrestore(&sclp_lock, flags);
+
+ /* Init supend data */
+ memset(&sclp_suspend_req, 0, sizeof(sclp_suspend_req));
+ sclp_suspend_req.callback = sclp_suspend_req_cb;
+ sclp_suspend_req.status = SCLP_REQ_FILLED;
+ init_completion(&sclp_request_queue_flushed);
+
+ rc = sclp_add_request(&sclp_suspend_req);
+ if (rc == 0)
+ wait_for_completion(&sclp_request_queue_flushed);
+ else if (rc != -ENODATA)
+ goto fail_thaw;
+
+ rc = sclp_deactivate();
+ if (rc)
+ goto fail_thaw;
+ return 0;
+
+fail_thaw:
+ spin_lock_irqsave(&sclp_lock, flags);
+ sclp_suspend_state = sclp_suspend_state_running;
+ spin_unlock_irqrestore(&sclp_lock, flags);
+ sclp_pm_event(SCLP_PM_EVENT_THAW, 1);
+ return rc;
+}
+
+static int sclp_undo_suspend(enum sclp_pm_event event)
+{
+ unsigned long flags;
+ int rc;
+
+ rc = sclp_reactivate();
+ if (rc)
+ return rc;
+
+ spin_lock_irqsave(&sclp_lock, flags);
+ sclp_suspend_state = sclp_suspend_state_running;
+ spin_unlock_irqrestore(&sclp_lock, flags);
+
+ sclp_pm_event(event, 0);
+ return 0;
+}
+
+static int sclp_thaw(struct device *dev)
+{
+ return sclp_undo_suspend(SCLP_PM_EVENT_THAW);
+}
+
+static int sclp_restore(struct device *dev)
+{
+ return sclp_undo_suspend(SCLP_PM_EVENT_RESTORE);
+}
+
+static struct dev_pm_ops sclp_pm_ops = {
+ .freeze = sclp_freeze,
+ .thaw = sclp_thaw,
+ .restore = sclp_restore,
+};
+
+static struct platform_driver sclp_pdrv = {
+ .driver = {
+ .name = "sclp",
+ .owner = THIS_MODULE,
+ .pm = &sclp_pm_ops,
+ },
+};
+
+static struct platform_device *sclp_pdev;
+
/* Initialize SCLP driver. Return zero if driver is operational, non-zero
* otherwise. */
static int
sclp_init(void)
{
unsigned long flags;
- int rc;
+ int rc = 0;
spin_lock_irqsave(&sclp_lock, flags);
/* Check for previous or running initialization */
- if (sclp_init_state != sclp_init_state_uninitialized) {
- spin_unlock_irqrestore(&sclp_lock, flags);
- return 0;
- }
+ if (sclp_init_state != sclp_init_state_uninitialized)
+ goto fail_unlock;
sclp_init_state = sclp_init_state_initializing;
/* Set up variables */
INIT_LIST_HEAD(&sclp_req_queue);
@@ -904,27 +1057,17 @@ sclp_init(void)
spin_unlock_irqrestore(&sclp_lock, flags);
rc = sclp_check_interface();
spin_lock_irqsave(&sclp_lock, flags);
- if (rc) {
- sclp_init_state = sclp_init_state_uninitialized;
- spin_unlock_irqrestore(&sclp_lock, flags);
- return rc;
- }
+ if (rc)
+ goto fail_init_state_uninitialized;
/* Register reboot handler */
rc = register_reboot_notifier(&sclp_reboot_notifier);
- if (rc) {
- sclp_init_state = sclp_init_state_uninitialized;
- spin_unlock_irqrestore(&sclp_lock, flags);
- return rc;
- }
+ if (rc)
+ goto fail_init_state_uninitialized;
/* Register interrupt handler */
rc = register_early_external_interrupt(0x2401, sclp_interrupt_handler,
&ext_int_info_hwc);
- if (rc) {
- unregister_reboot_notifier(&sclp_reboot_notifier);
- sclp_init_state = sclp_init_state_uninitialized;
- spin_unlock_irqrestore(&sclp_lock, flags);
- return rc;
- }
+ if (rc)
+ goto fail_unregister_reboot_notifier;
sclp_init_state = sclp_init_state_initialized;
spin_unlock_irqrestore(&sclp_lock, flags);
/* Enable service-signal external interruption - needs to happen with
@@ -932,11 +1075,56 @@ sclp_init(void)
ctl_set_bit(0, 9);
sclp_init_mask(1);
return 0;
+
+fail_unregister_reboot_notifier:
+ unregister_reboot_notifier(&sclp_reboot_notifier);
+fail_init_state_uninitialized:
+ sclp_init_state = sclp_init_state_uninitialized;
+fail_unlock:
+ spin_unlock_irqrestore(&sclp_lock, flags);
+ return rc;
}
+/*
+ * SCLP panic notifier: If we are suspended, we thaw SCLP in order to be able
+ * to print the panic message.
+ */
+static int sclp_panic_notify(struct notifier_block *self,
+ unsigned long event, void *data)
+{
+ if (sclp_suspend_state == sclp_suspend_state_suspended)
+ sclp_undo_suspend(SCLP_PM_EVENT_THAW);
+ return NOTIFY_OK;
+}
+
+static struct notifier_block sclp_on_panic_nb = {
+ .notifier_call = sclp_panic_notify,
+ .priority = SCLP_PANIC_PRIO,
+};
+
static __init int sclp_initcall(void)
{
+ int rc;
+
+ rc = platform_driver_register(&sclp_pdrv);
+ if (rc)
+ return rc;
+ sclp_pdev = platform_device_register_simple("sclp", -1, NULL, 0);
+ rc = IS_ERR(sclp_pdev) ? PTR_ERR(sclp_pdev) : 0;
+ if (rc)
+ goto fail_platform_driver_unregister;
+ rc = atomic_notifier_chain_register(&panic_notifier_list,
+ &sclp_on_panic_nb);
+ if (rc)
+ goto fail_platform_device_unregister;
+
return sclp_init();
+
+fail_platform_device_unregister:
+ platform_device_unregister(sclp_pdev);
+fail_platform_driver_unregister:
+ platform_driver_unregister(&sclp_pdrv);
+ return rc;
}
arch_initcall(sclp_initcall);