diff options
Diffstat (limited to 'drivers/char/ipmi/ipmi_msghandler.c')
| -rw-r--r-- | drivers/char/ipmi/ipmi_msghandler.c | 246 |
1 files changed, 170 insertions, 76 deletions
diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 6a77b264eb2..03f32611831 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -200,6 +200,10 @@ struct ipmi_smi * protects this. */ struct list_head users; + /* Information to supply to users. */ + unsigned char ipmi_version_major; + unsigned char ipmi_version_minor; + /* Used for wake ups at startup. */ wait_queue_head_t waitq; @@ -207,7 +211,10 @@ struct ipmi_smi char *my_dev_name; char *sysfs_name; - /* This is the lower-layer's sender routine. */ + /* This is the lower-layer's sender routine. Note that you + * must either be holding the ipmi_interfaces_mutex or be in + * an umpreemptible region to use this. You must fetch the + * value into a local variable and make sure it is not NULL. */ struct ipmi_smi_handlers *handlers; void *send_info; @@ -246,6 +253,7 @@ struct ipmi_smi spinlock_t events_lock; /* For dealing with event stuff. */ struct list_head waiting_events; unsigned int waiting_events_count; /* How many events in queue? */ + int delivering_events; /* The event receiver for my BMC, only really used at panic shutdown as a place to store this. */ @@ -357,7 +365,7 @@ static DEFINE_MUTEX(ipmi_interfaces_mutex); /* List of watchers that want to know when smi's are added and deleted. */ static struct list_head smi_watchers = LIST_HEAD_INIT(smi_watchers); -static DECLARE_RWSEM(smi_watchers_sem); +static DEFINE_MUTEX(smi_watchers_mutex); static void free_recv_msg_list(struct list_head *q) @@ -418,8 +426,9 @@ static void intf_free(struct kref *ref) } struct watcher_entry { + int intf_num; + ipmi_smi_t intf; struct list_head link; - int intf_num; }; int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher) @@ -428,36 +437,45 @@ int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher) struct list_head to_deliver = LIST_HEAD_INIT(to_deliver); struct watcher_entry *e, *e2; + mutex_lock(&smi_watchers_mutex); + mutex_lock(&ipmi_interfaces_mutex); + /* Build a list of things to deliver. */ list_for_each_entry_rcu(intf, &ipmi_interfaces, link) { if (intf->intf_num == -1) continue; e = kmalloc(sizeof(*e), GFP_KERNEL); if (!e) goto out_err; + kref_get(&intf->refcount); + e->intf = intf; e->intf_num = intf->intf_num; list_add_tail(&e->link, &to_deliver); } - down_write(&smi_watchers_sem); - list_add(&(watcher->link), &smi_watchers); - up_write(&smi_watchers_sem); + /* We will succeed, so add it to the list. */ + list_add(&watcher->link, &smi_watchers); mutex_unlock(&ipmi_interfaces_mutex); list_for_each_entry_safe(e, e2, &to_deliver, link) { list_del(&e->link); - watcher->new_smi(e->intf_num, intf->si_dev); + watcher->new_smi(e->intf_num, e->intf->si_dev); + kref_put(&e->intf->refcount, intf_free); kfree(e); } + mutex_unlock(&smi_watchers_mutex); return 0; out_err: + mutex_unlock(&ipmi_interfaces_mutex); + mutex_unlock(&smi_watchers_mutex); list_for_each_entry_safe(e, e2, &to_deliver, link) { list_del(&e->link); + kref_put(&e->intf->refcount, intf_free); kfree(e); } return -ENOMEM; @@ -465,25 +483,26 @@ int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher) int ipmi_smi_watcher_unregister(struct ipmi_smi_watcher *watcher) { - down_write(&smi_watchers_sem); + mutex_lock(&smi_watchers_mutex); list_del(&(watcher->link)); - up_write(&smi_watchers_sem); + mutex_unlock(&smi_watchers_mutex); return 0; } +/* + * Must be called with smi_watchers_mutex held. + */ static void call_smi_watchers(int i, struct device *dev) { struct ipmi_smi_watcher *w; - down_read(&smi_watchers_sem); list_for_each_entry(w, &smi_watchers, link) { if (try_module_get(w->owner)) { w->new_smi(i, dev); module_put(w->owner); } } - up_read(&smi_watchers_sem); } static int @@ -609,6 +628,17 @@ static void deliver_response(struct ipmi_recv_msg *msg) } } +static void +deliver_err_response(struct ipmi_recv_msg *msg, int err) +{ + msg->recv_type = IPMI_RESPONSE_RECV_TYPE; + msg->msg_data[0] = err; + msg->msg.netfn |= 1; /* Convert to a response. */ + msg->msg.data_len = 1; + msg->msg.data = msg->msg_data; + deliver_response(msg); +} + /* Find the next sequence number not being used and add the given message with the given timeout to the sequence table. This must be called with the interface's seq_lock held. */ @@ -746,14 +776,8 @@ static int intf_err_seq(ipmi_smi_t intf, } spin_unlock_irqrestore(&(intf->seq_lock), flags); - if (msg) { - msg->recv_type = IPMI_RESPONSE_RECV_TYPE; - msg->msg_data[0] = err; - msg->msg.netfn |= 1; /* Convert to a response. */ - msg->msg.data_len = 1; - msg->msg.data = msg->msg_data; - deliver_response(msg); - } + if (msg) + deliver_err_response(msg, err); return rv; } @@ -795,19 +819,18 @@ int ipmi_create_user(unsigned int if_num, if (!new_user) return -ENOMEM; - rcu_read_lock(); + mutex_lock(&ipmi_interfaces_mutex); list_for_each_entry_rcu(intf, &ipmi_interfaces, link) { if (intf->intf_num == if_num) goto found; } - rcu_read_unlock(); + /* Not found, return an error */ rv = -EINVAL; goto out_kfree; found: /* Note that each existing user holds a refcount to the interface. */ kref_get(&intf->refcount); - rcu_read_unlock(); kref_init(&new_user->refcount); new_user->handler = handler; @@ -828,6 +851,10 @@ int ipmi_create_user(unsigned int if_num, } } + /* Hold the lock so intf->handlers is guaranteed to be good + * until now */ + mutex_unlock(&ipmi_interfaces_mutex); + new_user->valid = 1; spin_lock_irqsave(&intf->seq_lock, flags); list_add_rcu(&new_user->link, &intf->users); @@ -838,6 +865,7 @@ int ipmi_create_user(unsigned int if_num, out_kref: kref_put(&intf->refcount, intf_free); out_kfree: + mutex_unlock(&ipmi_interfaces_mutex); kfree(new_user); return rv; } @@ -867,6 +895,7 @@ int ipmi_destroy_user(ipmi_user_t user) && (intf->seq_table[i].recv_msg->user == user)) { intf->seq_table[i].inuse = 0; + ipmi_free_recv_msg(intf->seq_table[i].recv_msg); } } spin_unlock_irqrestore(&intf->seq_lock, flags); @@ -893,9 +922,13 @@ int ipmi_destroy_user(ipmi_user_t user) kfree(rcvr); } - module_put(intf->handlers->owner); - if (intf->handlers->dec_usecount) - intf->handlers->dec_usecount(intf->send_info); + mutex_lock(&ipmi_interfaces_mutex); + if (intf->handlers) { + module_put(intf->handlers->owner); + if (intf->handlers->dec_usecount) + intf->handlers->dec_usecount(intf->send_info); + } + mutex_unlock(&ipmi_interfaces_mutex); kref_put(&intf->refcount, intf_free); @@ -908,8 +941,8 @@ void ipmi_get_version(ipmi_user_t user, unsigned char *major, unsigned char *minor) { - *major = ipmi_version_major(&user->intf->bmc->id); - *minor = ipmi_version_minor(&user->intf->bmc->id); + *major = user->intf->ipmi_version_major; + *minor = user->intf->ipmi_version_minor; } int ipmi_set_my_address(ipmi_user_t user, @@ -964,20 +997,33 @@ int ipmi_set_gets_events(ipmi_user_t user, int val) spin_lock_irqsave(&intf->events_lock, flags); user->gets_events = val; - if (val) { - /* Deliver any queued events. */ + if (intf->delivering_events) + /* + * Another thread is delivering events for this, so + * let it handle any new events. + */ + goto out; + + /* Deliver any queued events. */ + while (user->gets_events && !list_empty(&intf->waiting_events)) { list_for_each_entry_safe(msg, msg2, &intf->waiting_events, link) list_move_tail(&msg->link, &msgs); intf->waiting_events_count = 0; - } - /* Hold the events lock while doing this to preserve order. */ - list_for_each_entry_safe(msg, msg2, &msgs, link) { - msg->user = user; - kref_get(&user->refcount); - deliver_response(msg); + intf->delivering_events = 1; + spin_unlock_irqrestore(&intf->events_lock, flags); + + list_for_each_entry_safe(msg, msg2, &msgs, link) { + msg->user = user; + kref_get(&user->refcount); + deliver_response(msg); + } + + spin_lock_irqsave(&intf->events_lock, flags); + intf->delivering_events = 0; } + out: spin_unlock_irqrestore(&intf->events_lock, flags); return 0; @@ -1088,7 +1134,8 @@ int ipmi_unregister_for_cmd(ipmi_user_t user, void ipmi_user_set_run_to_completion(ipmi_user_t user, int val) { ipmi_smi_t intf = user->intf; - intf->handlers->set_run_to_completion(intf->send_info, val); + if (intf->handlers) + intf->handlers->set_run_to_completion(intf->send_info, val); } static unsigned char @@ -1199,10 +1246,11 @@ static int i_ipmi_request(ipmi_user_t user, int retries, unsigned int retry_time_ms) { - int rv = 0; - struct ipmi_smi_msg *smi_msg; - struct ipmi_recv_msg *recv_msg; - unsigned long flags; + int rv = 0; + struct ipmi_smi_msg *smi_msg; + struct ipmi_recv_msg *recv_msg; + unsigned long flags; + struct ipmi_smi_handlers *handlers; if (supplied_recv) { @@ -1225,6 +1273,13 @@ static int i_ipmi_request(ipmi_user_t user, } } + rcu_read_lock(); + handlers = intf->handlers; + if (!handlers) { + rv = -ENODEV; + goto out_err; + } + recv_msg->user = user; if (user) kref_get(&user->refcount); @@ -1541,11 +1596,14 @@ static int i_ipmi_request(ipmi_user_t user, printk("\n"); } #endif - intf->handlers->sender(intf->send_info, smi_msg, priority); + + handlers->sender(intf->send_info, smi_msg, priority); + rcu_read_unlock(); return 0; out_err: + rcu_read_unlock(); ipmi_free_smi_msg(smi_msg); ipmi_free_recv_msg(recv_msg); return rv; @@ -2492,13 +2550,8 @@ int ipmi_register_smi(struct ipmi_smi_handlers *handlers, int rv; ipmi_smi_t intf; ipmi_smi_t tintf; - int version_major; - int version_minor; struct list_head *link; - version_major = ipmi_version_major(device_id); - version_minor = ipmi_version_minor(device_id); - /* Make sure the driver is actually initialized, this handles problems with initialization order. */ if (!initialized) { @@ -2515,6 +2568,10 @@ int ipmi_register_smi(struct ipmi_smi_handlers *handlers, if (!intf) return -ENOMEM; memset(intf, 0, sizeof(*intf)); + + intf->ipmi_version_major = ipmi_version_major(device_id); + intf->ipmi_version_minor = ipmi_version_minor(device_id); + intf->bmc = kzalloc(sizeof(*intf->bmc), GFP_KERNEL); if (!intf->bmc) { kfree(intf); @@ -2554,6 +2611,7 @@ int ipmi_register_smi(struct ipmi_smi_handlers *handlers, spin_lock_init(&intf->counter_lock); intf->proc_dir = NULL; + mutex_lock(&smi_watchers_mutex); mutex_lock(&ipmi_interfaces_mutex); /* Look for a hole in the numbers. */ i = 0; @@ -2577,8 +2635,9 @@ int ipmi_register_smi(struct ipmi_smi_handlers *handlers, get_guid(intf); - if ((version_major > 1) - || ((version_major == 1) && (version_minor >= 5))) + if ((intf->ipmi_version_major > 1) + || ((intf->ipmi_version_major == 1) + && (intf->ipmi_version_minor >= 5))) { /* Start scanning the channels to see what is available. */ @@ -2607,8 +2666,10 @@ int ipmi_register_smi(struct ipmi_smi_handlers *handlers, if (rv) { if (intf->proc_dir) remove_proc_entries(intf); + intf->handlers = NULL; list_del_rcu(&intf->link); mutex_unlock(&ipmi_interfaces_mutex); + mutex_unlock(&smi_watchers_mutex); synchronize_rcu(); kref_put(&intf->refcount, intf_free); } else { @@ -2616,30 +2677,50 @@ int ipmi_register_smi(struct ipmi_smi_handlers *handlers, intf->intf_num = i; mutex_unlock(&ipmi_interfaces_mutex); call_smi_watchers(i, intf->si_dev); + mutex_unlock(&smi_watchers_mutex); } return rv; } +static void cleanup_smi_msgs(ipmi_smi_t intf) +{ + int i; + struct seq_table *ent; + + /* No need for locks, the interface is down. */ + for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) { + ent = &(intf->seq_table[i]); + if (!ent->inuse) + continue; + deliver_err_response(ent->recv_msg, IPMI_ERR_UNSPECIFIED); + } +} + int ipmi_unregister_smi(ipmi_smi_t intf) { struct ipmi_smi_watcher *w; + int intf_num = intf->intf_num; ipmi_bmc_unregister(intf); + mutex_lock(&smi_watchers_mutex); mutex_lock(&ipmi_interfaces_mutex); + intf->intf_num = -1; + intf->handlers = NULL; list_del_rcu(&intf->link); mutex_unlock(&ipmi_interfaces_mutex); synchronize_rcu(); + cleanup_smi_msgs(intf); + remove_proc_entries(intf); /* Call all the watcher interfaces to tell them that an interface is gone. */ - down_read(&smi_watchers_sem); list_for_each_entry(w, &smi_watchers, link) - w->smi_gone(intf->intf_num); - up_read(&smi_watchers_sem); + w->smi_gone(intf_num); + mutex_unlock(&smi_watchers_mutex); kref_put(&intf->refcount, intf_free); return 0; @@ -2721,6 +2802,7 @@ static int handle_ipmb_get_msg_cmd(ipmi_smi_t intf, struct ipmi_ipmb_addr *ipmb_addr; struct ipmi_recv_msg *recv_msg; unsigned long flags; + struct ipmi_smi_handlers *handlers; if (msg->rsp_size < 10) { /* Message not big enough, just ignore it. */ @@ -2777,10 +2859,16 @@ static int handle_ipmb_get_msg_cmd(ipmi_smi_t intf, printk("\n"); } #endif - intf->handlers->sender(intf->send_info, msg, 0); - - rv = -1; /* We used the message, so return the value that - causes it to not be freed or queued. */ + rcu_read_lock(); + handlers = intf->handlers; + if (handlers) { + handlers->sender(intf->send_info, msg, 0); + /* We used the message, so return the value + that causes it to not be freed or + queued. */ + rv = -1; + } + rcu_read_unlock(); } else { /* Deliver the message to the user. */ spin_lock_irqsave(&intf->counter_lock, flags); @@ -3370,16 +3458,6 @@ void ipmi_smi_watchdog_pretimeout(ipmi_smi_t intf) rcu_read_unlock(); } -static void -handle_msg_timeout(struct ipmi_recv_msg *msg) -{ - msg->recv_type = IPMI_RESPONSE_RECV_TYPE; - msg->msg_data[0] = IPMI_TIMEOUT_COMPLETION_CODE; - msg->msg.netfn |= 1; /* Convert to a response. */ - msg->msg.data_len = 1; - msg->msg.data = msg->msg_data; - deliver_response(msg); -} static struct ipmi_smi_msg * smi_from_recv_msg(ipmi_smi_t intf, struct ipmi_recv_msg *recv_msg, @@ -3411,7 +3489,11 @@ static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent, struct list_head *timeouts, long timeout_period, int slot, unsigned long *flags) { - struct ipmi_recv_msg *msg; + struct ipmi_recv_msg *msg; + struct ipmi_smi_handlers *handlers; + + if (intf->intf_num == -1) + return; if (!ent->inuse) return; @@ -3454,13 +3536,19 @@ static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent, return; spin_unlock_irqrestore(&intf->seq_lock, *flags); + /* Send the new message. We send with a zero * priority. It timed out, I doubt time is * that critical now, and high priority * messages are really only for messages to the * local MC, which don't get resent. */ - intf->handlers->sender(intf->send_info, - smi_msg, 0); + handlers = intf->handlers; + if (handlers) + intf->handlers->sender(intf->send_info, + smi_msg, 0); + else + ipmi_free_smi_msg(smi_msg); + spin_lock_irqsave(&intf->seq_lock, *flags); } } @@ -3504,18 +3592,24 @@ static void ipmi_timeout_handler(long timeout_period) spin_unlock_irqrestore(&intf->seq_lock, flags); list_for_each_entry_safe(msg, msg2, &timeouts, link) - handle_msg_timeout(msg); + deliver_err_response(msg, IPMI_TIMEOUT_COMPLETION_CODE); } rcu_read_unlock(); } static void ipmi_request_event(void) { - ipmi_smi_t intf; + ipmi_smi_t intf; + struct ipmi_smi_handlers *handlers; rcu_read_lock(); - list_for_each_entry_rcu(intf, &ipmi_interfaces, link) - intf->handlers->request_events(intf->send_info); + /* Called from the timer, no need to check if handlers is + * valid. */ + list_for_each_entry_rcu(intf, &ipmi_interfaces, link) { + handlers = intf->handlers; + if (handlers) + handlers->request_events(intf->send_info); + } rcu_read_unlock(); } @@ -3679,8 +3773,8 @@ static void send_panic_events(char *str) /* For every registered interface, send the event. */ list_for_each_entry_rcu(intf, &ipmi_interfaces, link) { - if (intf->intf_num == -1) - /* Interface was not ready yet. */ + if (!intf->handlers) + /* Interface is not ready. */ continue; /* Send the event announcing the panic. */ @@ -3846,8 +3940,8 @@ static int panic_event(struct notifier_block *this, /* For every registered interface, set it to run to completion. */ list_for_each_entry_rcu(intf, &ipmi_interfaces, link) { - if (intf->intf_num == -1) - /* Interface was not ready yet. */ + if (!intf->handlers) + /* Interface is not ready. */ continue; intf->handlers->set_run_to_completion(intf->send_info, 1); |