diff options
Diffstat (limited to 'drivers/s390/char/sclp.c')
| -rw-r--r-- | drivers/s390/char/sclp.c | 248 |
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(®->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); |