diff options
Diffstat (limited to 'drivers/s390/char/sclp.c')
| -rw-r--r-- | drivers/s390/char/sclp.c | 93 |
1 files changed, 62 insertions, 31 deletions
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c index 8a056df..f171de3 100644 --- a/drivers/s390/char/sclp.c +++ b/drivers/s390/char/sclp.c @@ -59,7 +59,8 @@ static volatile enum sclp_init_state_t { /* Internal state: is a request active at the sclp? */ static volatile enum sclp_running_state_t { sclp_running_state_idle, - sclp_running_state_running + sclp_running_state_running, + sclp_running_state_reset_pending } sclp_running_state = sclp_running_state_idle; /* Internal state: is a read request pending? */ @@ -88,15 +89,15 @@ static volatile enum sclp_mask_state_t { /* Timeout intervals in seconds.*/ #define SCLP_BUSY_INTERVAL 10 -#define SCLP_RETRY_INTERVAL 15 +#define SCLP_RETRY_INTERVAL 30 static void sclp_process_queue(void); static int sclp_init_mask(int calculate); static int sclp_init(void); /* Perform service call. Return 0 on success, non-zero otherwise. */ -static int -service_call(sclp_cmdw_t command, void *sccb) +int +sclp_service_call(sclp_cmdw_t command, void *sccb) { int cc; @@ -113,19 +114,17 @@ service_call(sclp_cmdw_t command, void *sccb) return 0; } -/* Request timeout handler. Restart the request queue. If DATA is non-zero, - * force restart of running request. */ +static inline void __sclp_make_read_req(void); + static void -sclp_request_timeout(unsigned long data) +__sclp_queue_read_req(void) { - unsigned long flags; - - if (data) { - spin_lock_irqsave(&sclp_lock, flags); - sclp_running_state = sclp_running_state_idle; - spin_unlock_irqrestore(&sclp_lock, flags); + if (sclp_reading_state == sclp_reading_state_idle) { + sclp_reading_state = sclp_reading_state_reading; + __sclp_make_read_req(); + /* Add request to head of queue */ + list_add(&sclp_read_req.list, &sclp_req_queue); } - sclp_process_queue(); } /* Set up request retry timer. Called while sclp_lock is locked. */ @@ -140,6 +139,29 @@ __sclp_set_request_timer(unsigned long time, void (*function)(unsigned long), add_timer(&sclp_request_timer); } +/* Request timeout handler. Restart the request queue. If DATA is non-zero, + * force restart of running request. */ +static void +sclp_request_timeout(unsigned long data) +{ + unsigned long flags; + + spin_lock_irqsave(&sclp_lock, flags); + if (data) { + if (sclp_running_state == sclp_running_state_running) { + /* Break running state and queue NOP read event request + * to get a defined interface state. */ + __sclp_queue_read_req(); + sclp_running_state = sclp_running_state_idle; + } + } else { + __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, + sclp_request_timeout, 0); + } + spin_unlock_irqrestore(&sclp_lock, flags); + sclp_process_queue(); +} + /* Try to start a request. Return zero if the request was successfully * started or if it will be started at a later time. Return non-zero otherwise. * Called while sclp_lock is locked. */ @@ -151,7 +173,7 @@ __sclp_start_request(struct sclp_req *req) if (sclp_running_state != sclp_running_state_idle) return 0; del_timer(&sclp_request_timer); - rc = service_call(req->command, req->sccb); + rc = sclp_service_call(req->command, req->sccb); req->start_count++; if (rc == 0) { @@ -191,7 +213,15 @@ sclp_process_queue(void) rc = __sclp_start_request(req); if (rc == 0) break; - /* Request failed. */ + /* Request failed */ + if (req->start_count > 1) { + /* Cannot abort already submitted request - could still + * be active at the SCLP */ + __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, + sclp_request_timeout, 0); + break; + } + /* Post-processing for aborted request */ list_del(&req->list); if (req->callback) { spin_unlock_irqrestore(&sclp_lock, flags); @@ -221,7 +251,8 @@ sclp_add_request(struct sclp_req *req) list_add_tail(&req->list, &sclp_req_queue); rc = 0; /* Start if request is first in list */ - if (req->list.prev == &sclp_req_queue) { + if (sclp_running_state == sclp_running_state_idle && + req->list.prev == &sclp_req_queue) { rc = __sclp_start_request(req); if (rc) list_del(&req->list); @@ -294,7 +325,7 @@ __sclp_make_read_req(void) sccb = (struct sccb_header *) sclp_read_sccb; clear_page(sccb); memset(&sclp_read_req, 0, sizeof(struct sclp_req)); - sclp_read_req.command = SCLP_CMDW_READDATA; + sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA; sclp_read_req.status = SCLP_REQ_QUEUED; sclp_read_req.start_count = 0; sclp_read_req.callback = sclp_read_cb; @@ -334,6 +365,8 @@ sclp_interrupt_handler(__u16 code) finished_sccb = S390_lowcore.ext_params & 0xfffffff8; evbuf_pending = S390_lowcore.ext_params & 0x3; if (finished_sccb) { + del_timer(&sclp_request_timer); + sclp_running_state = sclp_running_state_reset_pending; req = __sclp_find_req(finished_sccb); if (req) { /* Request post-processing */ @@ -348,13 +381,8 @@ sclp_interrupt_handler(__u16 code) sclp_running_state = sclp_running_state_idle; } if (evbuf_pending && sclp_receive_mask != 0 && - sclp_reading_state == sclp_reading_state_idle && - sclp_activation_state == sclp_activation_state_active ) { - sclp_reading_state = sclp_reading_state_reading; - __sclp_make_read_req(); - /* Add request to head of queue */ - list_add(&sclp_read_req.list, &sclp_req_queue); - } + sclp_activation_state == sclp_activation_state_active) + __sclp_queue_read_req(); spin_unlock(&sclp_lock); sclp_process_queue(); } @@ -374,6 +402,7 @@ sclp_sync_wait(void) unsigned long flags; unsigned long cr0, cr0_sync; u64 timeout; + int irq_context; /* We'll be disabling timer interrupts, so we need a custom timeout * mechanism */ @@ -386,7 +415,9 @@ sclp_sync_wait(void) } local_irq_save(flags); /* Prevent bottom half from executing once we force interrupts open */ - local_bh_disable(); + irq_context = in_interrupt(); + if (!irq_context) + local_bh_disable(); /* Enable service-signal interruption, disable timer interrupts */ trace_hardirqs_on(); __ctl_store(cr0, 0, 0); @@ -402,19 +433,19 @@ sclp_sync_wait(void) get_clock() > timeout && del_timer(&sclp_request_timer)) sclp_request_timer.function(sclp_request_timer.data); - barrier(); cpu_relax(); } local_irq_disable(); __ctl_load(cr0, 0, 0); - _local_bh_enable(); + if (!irq_context) + _local_bh_enable(); local_irq_restore(flags); } EXPORT_SYMBOL(sclp_sync_wait); /* Dispatch changes in send and receive mask to registered listeners. */ -static inline void +static void sclp_dispatch_state_change(void) { struct list_head *l; @@ -597,7 +628,7 @@ __sclp_make_init_req(u32 receive_mask, u32 send_mask) sccb = (struct init_sccb *) sclp_init_sccb; clear_page(sccb); memset(&sclp_init_req, 0, sizeof(struct sclp_req)); - sclp_init_req.command = SCLP_CMDW_WRITEMASK; + sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK; sclp_init_req.status = SCLP_REQ_FILLED; sclp_init_req.start_count = 0; sclp_init_req.callback = NULL; @@ -800,7 +831,7 @@ sclp_check_interface(void) for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) { __sclp_make_init_req(0, 0); sccb = (struct init_sccb *) sclp_init_req.sccb; - rc = service_call(sclp_init_req.command, sccb); + rc = sclp_service_call(sclp_init_req.command, sccb); if (rc == -EIO) break; sclp_init_req.status = SCLP_REQ_RUNNING; |