diff options
| -rw-r--r-- | drivers/s390/char/sclp.c | 82 | ||||
| -rw-r--r-- | drivers/s390/char/sclp.h | 9 | ||||
| -rw-r--r-- | drivers/s390/char/sclp_cmd.c | 17 |
3 files changed, 104 insertions, 4 deletions
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c index 1fe264379e0d..e9ede5980994 100644 --- a/drivers/s390/char/sclp.c +++ b/drivers/s390/char/sclp.c @@ -91,6 +91,9 @@ static struct sclp_req sclp_suspend_req; /* Timer for request retries. */ static struct timer_list sclp_request_timer; +/* Timer for queued requests. */ +static struct timer_list sclp_queue_timer; + /* Internal state: is the driver initialized? */ static volatile enum sclp_init_state_t { sclp_init_state_uninitialized, @@ -215,6 +218,76 @@ sclp_request_timeout(unsigned long data) sclp_process_queue(); } +/* + * Returns the expire value in jiffies of the next pending request timeout, + * if any. Needs to be called with sclp_lock. + */ +static unsigned long __sclp_req_queue_find_next_timeout(void) +{ + unsigned long expires_next = 0; + struct sclp_req *req; + + list_for_each_entry(req, &sclp_req_queue, list) { + if (!req->queue_expires) + continue; + if (!expires_next || + (time_before(req->queue_expires, expires_next))) + expires_next = req->queue_expires; + } + return expires_next; +} + +/* + * Returns expired request, if any, and removes it from the list. + */ +static struct sclp_req *__sclp_req_queue_remove_expired_req(void) +{ + unsigned long flags, now; + struct sclp_req *req; + + spin_lock_irqsave(&sclp_lock, flags); + now = jiffies; + /* Don't need list_for_each_safe because we break out after list_del */ + list_for_each_entry(req, &sclp_req_queue, list) { + if (!req->queue_expires) + continue; + if (time_before_eq(req->queue_expires, now)) { + if (req->status == SCLP_REQ_QUEUED) { + req->status = SCLP_REQ_QUEUED_TIMEOUT; + list_del(&req->list); + goto out; + } + } + } + req = NULL; +out: + spin_unlock_irqrestore(&sclp_lock, flags); + return req; +} + +/* + * Timeout handler for queued requests. Removes request from list and + * invokes callback. This timer can be set per request in situations where + * waiting too long would be harmful to the system, e.g. during SE reboot. + */ +static void sclp_req_queue_timeout(unsigned long data) +{ + unsigned long flags, expires_next; + struct sclp_req *req; + + do { + req = __sclp_req_queue_remove_expired_req(); + if (req && req->callback) + req->callback(req, req->callback_data); + } while (req); + + spin_lock_irqsave(&sclp_lock, flags); + expires_next = __sclp_req_queue_find_next_timeout(); + if (expires_next) + mod_timer(&sclp_queue_timer, expires_next); + spin_unlock_irqrestore(&sclp_lock, flags); +} + /* 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. */ @@ -317,6 +390,13 @@ sclp_add_request(struct sclp_req *req) req->start_count = 0; list_add_tail(&req->list, &sclp_req_queue); rc = 0; + if (req->queue_timeout) { + req->queue_expires = jiffies + req->queue_timeout * HZ; + if (!timer_pending(&sclp_queue_timer) || + time_after(sclp_queue_timer.expires, req->queue_expires)) + mod_timer(&sclp_queue_timer, req->queue_expires); + } else + req->queue_expires = 0; /* Start if request is first in list */ if (sclp_running_state == sclp_running_state_idle && req->list.prev == &sclp_req_queue) { @@ -1113,6 +1193,8 @@ sclp_init(void) INIT_LIST_HEAD(&sclp_reg_list); list_add(&sclp_state_change_event.list, &sclp_reg_list); init_timer(&sclp_request_timer); + init_timer(&sclp_queue_timer); + sclp_queue_timer.function = sclp_req_queue_timeout; /* Check interface */ spin_unlock_irqrestore(&sclp_lock, flags); rc = sclp_check_interface(); diff --git a/drivers/s390/char/sclp.h b/drivers/s390/char/sclp.h index fea76aed9eea..a68b5ec7d042 100644 --- a/drivers/s390/char/sclp.h +++ b/drivers/s390/char/sclp.h @@ -133,6 +133,11 @@ struct sclp_req { /* Callback that is called after reaching final status. */ void (*callback)(struct sclp_req *, void *data); void *callback_data; + int queue_timeout; /* request queue timeout (sec), set by + caller of sclp_add_request(), if + needed */ + /* Internal fields */ + unsigned long queue_expires; /* request queue timeout (jiffies) */ }; #define SCLP_REQ_FILLED 0x00 /* request is ready to be processed */ @@ -140,6 +145,9 @@ struct sclp_req { #define SCLP_REQ_RUNNING 0x02 /* request is currently running */ #define SCLP_REQ_DONE 0x03 /* request is completed successfully */ #define SCLP_REQ_FAILED 0x05 /* request is finally failed */ +#define SCLP_REQ_QUEUED_TIMEOUT 0x06 /* request on queue timed out */ + +#define SCLP_QUEUE_INTERVAL 5 /* timeout interval for request queue */ /* function pointers that a high level driver has to use for registration */ /* of some routines it wants to be called from the low level driver */ @@ -173,6 +181,7 @@ int sclp_deactivate(void); int sclp_reactivate(void); int sclp_service_call(sclp_cmdw_t command, void *sccb); int sclp_sync_request(sclp_cmdw_t command, void *sccb); +int sclp_sync_request_timeout(sclp_cmdw_t command, void *sccb, int timeout); int sclp_sdias_init(void); void sclp_sdias_exit(void); diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c index 49af8eeb90ea..6e8f90f84e49 100644 --- a/drivers/s390/char/sclp_cmd.c +++ b/drivers/s390/char/sclp_cmd.c @@ -37,6 +37,11 @@ static void sclp_sync_callback(struct sclp_req *req, void *data) int sclp_sync_request(sclp_cmdw_t cmd, void *sccb) { + return sclp_sync_request_timeout(cmd, sccb, 0); +} + +int sclp_sync_request_timeout(sclp_cmdw_t cmd, void *sccb, int timeout) +{ struct completion completion; struct sclp_req *request; int rc; @@ -44,6 +49,8 @@ int sclp_sync_request(sclp_cmdw_t cmd, void *sccb) request = kzalloc(sizeof(*request), GFP_KERNEL); if (!request) return -ENOMEM; + if (timeout) + request->queue_timeout = timeout; request->command = cmd; request->sccb = sccb; request->status = SCLP_REQ_FILLED; @@ -110,7 +117,8 @@ int sclp_get_cpu_info(struct sclp_cpu_info *info) if (!sccb) return -ENOMEM; sccb->header.length = sizeof(*sccb); - rc = sclp_sync_request(SCLP_CMDW_READ_CPU_INFO, sccb); + rc = sclp_sync_request_timeout(SCLP_CMDW_READ_CPU_INFO, sccb, + SCLP_QUEUE_INTERVAL); if (rc) goto out; if (sccb->header.response_code != 0x0010) { @@ -144,7 +152,7 @@ static int do_cpu_configure(sclp_cmdw_t cmd) if (!sccb) return -ENOMEM; sccb->header.length = sizeof(*sccb); - rc = sclp_sync_request(cmd, sccb); + rc = sclp_sync_request_timeout(cmd, sccb, SCLP_QUEUE_INTERVAL); if (rc) goto out; switch (sccb->header.response_code) { @@ -214,7 +222,7 @@ static int do_assign_storage(sclp_cmdw_t cmd, u16 rn) return -ENOMEM; sccb->header.length = PAGE_SIZE; sccb->rn = rn; - rc = sclp_sync_request(cmd, sccb); + rc = sclp_sync_request_timeout(cmd, sccb, SCLP_QUEUE_INTERVAL); if (rc) goto out; switch (sccb->header.response_code) { @@ -269,7 +277,8 @@ static int sclp_attach_storage(u8 id) if (!sccb) return -ENOMEM; sccb->header.length = PAGE_SIZE; - rc = sclp_sync_request(0x00080001 | id << 8, sccb); + rc = sclp_sync_request_timeout(0x00080001 | id << 8, sccb, + SCLP_QUEUE_INTERVAL); if (rc) goto out; switch (sccb->header.response_code) { |