diff options
Diffstat (limited to 'drivers/s390/char/sclp_vt220.c')
-rw-r--r-- | drivers/s390/char/sclp_vt220.c | 118 |
1 files changed, 79 insertions, 39 deletions
diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c index a839aa531d7c..5518e24946aa 100644 --- a/drivers/s390/char/sclp_vt220.c +++ b/drivers/s390/char/sclp_vt220.c @@ -1,10 +1,9 @@ /* - * drivers/s390/char/sclp_vt220.c - * SCLP VT220 terminal driver. + * SCLP VT220 terminal driver. * - * S390 version - * Copyright IBM Corp. 2003,2008 - * Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com> + * Copyright IBM Corp. 2003, 2009 + * + * Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com> */ #include <linux/module.h> @@ -69,8 +68,11 @@ static struct list_head sclp_vt220_empty; /* List of pending requests */ static struct list_head sclp_vt220_outqueue; -/* Number of requests in outqueue */ -static int sclp_vt220_outqueue_count; +/* Suspend mode flag */ +static int sclp_vt220_suspended; + +/* Flag that output queue is currently running */ +static int sclp_vt220_queue_running; /* Timer used for delaying write requests to merge subsequent messages into * a single buffer */ @@ -92,6 +94,8 @@ static int __initdata sclp_vt220_init_count; static int sclp_vt220_flush_later; static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf); +static void sclp_vt220_pm_event_fn(struct sclp_register *reg, + enum sclp_pm_event sclp_pm_event); static int __sclp_vt220_emit(struct sclp_vt220_request *request); static void sclp_vt220_emit_current(void); @@ -100,7 +104,8 @@ static struct sclp_register sclp_vt220_register = { .send_mask = EVTYP_VT220MSG_MASK, .receive_mask = EVTYP_VT220MSG_MASK, .state_change_fn = NULL, - .receiver_fn = sclp_vt220_receiver_fn + .receiver_fn = sclp_vt220_receiver_fn, + .pm_event_fn = sclp_vt220_pm_event_fn, }; @@ -120,15 +125,19 @@ sclp_vt220_process_queue(struct sclp_vt220_request *request) spin_lock_irqsave(&sclp_vt220_lock, flags); /* Move request from outqueue to empty queue */ list_del(&request->list); - sclp_vt220_outqueue_count--; list_add_tail((struct list_head *) page, &sclp_vt220_empty); /* Check if there is a pending buffer on the out queue. */ request = NULL; if (!list_empty(&sclp_vt220_outqueue)) request = list_entry(sclp_vt220_outqueue.next, struct sclp_vt220_request, list); + if (!request || sclp_vt220_suspended) { + sclp_vt220_queue_running = 0; + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + break; + } spin_unlock_irqrestore(&sclp_vt220_lock, flags); - } while (request && __sclp_vt220_emit(request)); + } while (__sclp_vt220_emit(request)); if (request == NULL && sclp_vt220_flush_later) sclp_vt220_emit_current(); /* Check if the tty needs a wake up call */ @@ -212,26 +221,7 @@ __sclp_vt220_emit(struct sclp_vt220_request *request) } /* - * Queue and emit given request. - */ -static void -sclp_vt220_emit(struct sclp_vt220_request *request) -{ - unsigned long flags; - int count; - - spin_lock_irqsave(&sclp_vt220_lock, flags); - list_add_tail(&request->list, &sclp_vt220_outqueue); - count = sclp_vt220_outqueue_count++; - spin_unlock_irqrestore(&sclp_vt220_lock, flags); - /* Emit only the first buffer immediately - callback takes care of - * the rest */ - if (count == 0 && __sclp_vt220_emit(request)) - sclp_vt220_process_queue(request); -} - -/* - * Queue and emit current request. Return zero on success, non-zero otherwise. + * Queue and emit current request. */ static void sclp_vt220_emit_current(void) @@ -241,22 +231,33 @@ sclp_vt220_emit_current(void) struct sclp_vt220_sccb *sccb; spin_lock_irqsave(&sclp_vt220_lock, flags); - request = NULL; - if (sclp_vt220_current_request != NULL) { + if (sclp_vt220_current_request) { sccb = (struct sclp_vt220_sccb *) sclp_vt220_current_request->sclp_req.sccb; /* Only emit buffers with content */ if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) { - request = sclp_vt220_current_request; + list_add_tail(&sclp_vt220_current_request->list, + &sclp_vt220_outqueue); sclp_vt220_current_request = NULL; if (timer_pending(&sclp_vt220_timer)) del_timer(&sclp_vt220_timer); } sclp_vt220_flush_later = 0; } + if (sclp_vt220_queue_running || sclp_vt220_suspended) + goto out_unlock; + if (list_empty(&sclp_vt220_outqueue)) + goto out_unlock; + request = list_first_entry(&sclp_vt220_outqueue, + struct sclp_vt220_request, list); + sclp_vt220_queue_running = 1; + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + + if (__sclp_vt220_emit(request)) + sclp_vt220_process_queue(request); + return; +out_unlock: spin_unlock_irqrestore(&sclp_vt220_lock, flags); - if (request != NULL) - sclp_vt220_emit(request); } #define SCLP_NORMAL_WRITE 0x00 @@ -396,7 +397,7 @@ __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule, if (sclp_vt220_current_request == NULL) { while (list_empty(&sclp_vt220_empty)) { spin_unlock_irqrestore(&sclp_vt220_lock, flags); - if (may_fail) + if (may_fail || sclp_vt220_suspended) goto out; else sclp_sync_wait(); @@ -531,7 +532,7 @@ sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch) static void sclp_vt220_flush_chars(struct tty_struct *tty) { - if (sclp_vt220_outqueue_count == 0) + if (!sclp_vt220_queue_running) sclp_vt220_emit_current(); else sclp_vt220_flush_later = 1; @@ -635,7 +636,6 @@ static int __init __sclp_vt220_init(int num_pages) init_timer(&sclp_vt220_timer); sclp_vt220_current_request = NULL; sclp_vt220_buffered_chars = 0; - sclp_vt220_outqueue_count = 0; sclp_vt220_tty = NULL; sclp_vt220_flush_later = 0; @@ -736,7 +736,7 @@ static void __sclp_vt220_flush_buffer(void) spin_lock_irqsave(&sclp_vt220_lock, flags); if (timer_pending(&sclp_vt220_timer)) del_timer(&sclp_vt220_timer); - while (sclp_vt220_outqueue_count > 0) { + while (sclp_vt220_queue_running) { spin_unlock_irqrestore(&sclp_vt220_lock, flags); sclp_sync_wait(); spin_lock_irqsave(&sclp_vt220_lock, flags); @@ -744,6 +744,46 @@ static void __sclp_vt220_flush_buffer(void) spin_unlock_irqrestore(&sclp_vt220_lock, flags); } +/* + * Resume console: If there are cached messages, emit them. + */ +static void sclp_vt220_resume(void) +{ + unsigned long flags; + + spin_lock_irqsave(&sclp_vt220_lock, flags); + sclp_vt220_suspended = 0; + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + sclp_vt220_emit_current(); +} + +/* + * Suspend console: Set suspend flag and flush console + */ +static void sclp_vt220_suspend(void) +{ + unsigned long flags; + + spin_lock_irqsave(&sclp_vt220_lock, flags); + sclp_vt220_suspended = 1; + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + __sclp_vt220_flush_buffer(); +} + +static void sclp_vt220_pm_event_fn(struct sclp_register *reg, + enum sclp_pm_event sclp_pm_event) +{ + switch (sclp_pm_event) { + case SCLP_PM_EVENT_FREEZE: + sclp_vt220_suspend(); + break; + case SCLP_PM_EVENT_RESTORE: + case SCLP_PM_EVENT_THAW: + sclp_vt220_resume(); + break; + } +} + static int sclp_vt220_notify(struct notifier_block *self, unsigned long event, void *data) |