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ipmi: Make the smi watcher be disabled immediately when not needed

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The code to tell the lower layer to enable or disable watching for
certain things was lazy in disabling, it waited until a timer tick
to see if a disable was necessary.  Not a really big deal, but it
could be improved.

Modify the code to enable and disable watching immediately and don't
do it from the background timer any more.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Tested-by: Kamlakant Patel <kamlakant.patel@cavium.com>
This commit is contained in:
Corey Minyard 2018-10-24 15:17:04 -05:00
parent c65ea99659
commit e1891cffd4
4 changed files with 96 additions and 89 deletions
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164
drivers/char/ipmi/ipmi_msghandler.c
View File

@ -534,15 +534,20 @@ struct ipmi_smi {
atomic_t event_waiters;
unsigned int ticks_to_req_ev;
spinlock_t watch_lock; /* For dealing with watch stuff below. */
/* How many users are waiting for commands? */
atomic_t command_waiters;
unsigned int command_waiters;
/* How many users are waiting for watchdogs? */
atomic_t watchdog_waiters;
unsigned int watchdog_waiters;
/* How many users are waiting for message responses? */
unsigned int response_waiters;
/*
* Tells what the lower layer has last been asked to watch for,
* messages and/or watchdogs. Protected by xmit_msgs_lock.
* messages and/or watchdogs. Protected by watch_lock.
*/
unsigned int last_watch_mask;
@ -938,6 +943,64 @@ static void deliver_err_response(struct ipmi_smi *intf,
deliver_local_response(intf, msg);
}
static void smi_add_watch(struct ipmi_smi *intf, unsigned int flags)
{
unsigned long iflags;
if (!intf->handlers->set_need_watch)
return;
spin_lock_irqsave(&intf->watch_lock, iflags);
if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES)
intf->response_waiters++;
if (flags & IPMI_WATCH_MASK_CHECK_WATCHDOG)
intf->watchdog_waiters++;
if (flags & IPMI_WATCH_MASK_CHECK_COMMANDS)
intf->command_waiters++;
if ((intf->last_watch_mask & flags) != flags) {
intf->last_watch_mask |= flags;
intf->handlers->set_need_watch(intf->send_info,
intf->last_watch_mask);
}
spin_unlock_irqrestore(&intf->watch_lock, iflags);
}
static void smi_remove_watch(struct ipmi_smi *intf, unsigned int flags)
{
unsigned long iflags;
if (!intf->handlers->set_need_watch)
return;
spin_lock_irqsave(&intf->watch_lock, iflags);
if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES)
intf->response_waiters--;
if (flags & IPMI_WATCH_MASK_CHECK_WATCHDOG)
intf->watchdog_waiters--;
if (flags & IPMI_WATCH_MASK_CHECK_COMMANDS)
intf->command_waiters--;
flags = 0;
if (intf->response_waiters)
flags |= IPMI_WATCH_MASK_CHECK_MESSAGES;
if (intf->watchdog_waiters)
flags |= IPMI_WATCH_MASK_CHECK_WATCHDOG;
if (intf->command_waiters)
flags |= IPMI_WATCH_MASK_CHECK_COMMANDS;
if (intf->last_watch_mask != flags) {
intf->last_watch_mask = flags;
intf->handlers->set_need_watch(intf->send_info,
intf->last_watch_mask);
}
spin_unlock_irqrestore(&intf->watch_lock, iflags);
}
/*
* Find the next sequence number not being used and add the given
* message with the given timeout to the sequence table. This must be
@ -981,6 +1044,7 @@ static int intf_next_seq(struct ipmi_smi *intf,
*seq = i;
*seqid = intf->seq_table[i].seqid;
intf->curr_seq = (i+1)%IPMI_IPMB_NUM_SEQ;
smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
need_waiter(intf);
} else {
rv = -EAGAIN;
@ -1019,6 +1083,7 @@ static int intf_find_seq(struct ipmi_smi *intf,
&& (ipmi_addr_equal(addr, &msg->addr))) {
*recv_msg = msg;
intf->seq_table[seq].inuse = 0;
smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
rv = 0;
}
}
@ -1080,6 +1145,7 @@ static int intf_err_seq(struct ipmi_smi *intf,
struct seq_table *ent = &intf->seq_table[seq];
ent->inuse = 0;
smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
msg = ent->recv_msg;
rv = 0;
}
@ -1091,30 +1157,6 @@ static int intf_err_seq(struct ipmi_smi *intf,
return rv;
}
/* Must be called with xmit_msgs_lock held. */
static void smi_tell_to_watch(struct ipmi_smi *intf,
unsigned int flags,
struct ipmi_smi_msg *smi_msg)
{
if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES) {
if (!smi_msg)
return;
if (!smi_msg->needs_response)
return;
}
if (!intf->handlers->set_need_watch)
return;
if ((intf->last_watch_mask & flags) == flags)
return;
intf->last_watch_mask |= flags;
intf->handlers->set_need_watch(intf->send_info,
intf->last_watch_mask);
}
int ipmi_create_user(unsigned int if_num,
const struct ipmi_user_hndl *handler,
void *handler_data,
@ -1175,12 +1217,9 @@ int ipmi_create_user(unsigned int if_num,
spin_lock_irqsave(&intf->seq_lock, flags);
list_add_rcu(&new_user->link, &intf->users);
spin_unlock_irqrestore(&intf->seq_lock, flags);
if (handler->ipmi_watchdog_pretimeout) {
if (handler->ipmi_watchdog_pretimeout)
/* User wants pretimeouts, so make sure to watch for them. */
if (atomic_inc_return(&intf->watchdog_waiters) == 1)
smi_tell_to_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG,
NULL);
}
smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG);
srcu_read_unlock(&ipmi_interfaces_srcu, index);
*user = new_user;
return 0;
@ -1251,7 +1290,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
user->handler->shutdown(user->handler_data);
if (user->handler->ipmi_watchdog_pretimeout)
atomic_dec(&intf->watchdog_waiters);
smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG);
if (user->gets_events)
atomic_dec(&intf->event_waiters);
@ -1264,6 +1303,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
if (intf->seq_table[i].inuse
&& (intf->seq_table[i].recv_msg->user == user)) {
intf->seq_table[i].inuse = 0;
smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
}
}
@ -1606,8 +1646,7 @@ int ipmi_register_for_cmd(struct ipmi_user *user,
goto out_unlock;
}
if (atomic_inc_return(&intf->command_waiters) == 1)
smi_tell_to_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS, NULL);
smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS);
list_add_rcu(&rcvr->link, &intf->cmd_rcvrs);
@ -1657,7 +1696,7 @@ int ipmi_unregister_for_cmd(struct ipmi_user *user,
synchronize_rcu();
release_ipmi_user(user, index);
while (rcvrs) {
atomic_dec(&intf->command_waiters);
smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS);
rcvr = rcvrs;
rcvrs = rcvr->next;
kfree(rcvr);
@ -1785,8 +1824,6 @@ static void smi_send(struct ipmi_smi *intf,
spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
smi_msg = smi_add_send_msg(intf, smi_msg, priority);
smi_tell_to_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES, smi_msg);
if (!run_to_completion)
spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
@ -1986,9 +2023,6 @@ static int i_ipmi_req_ipmb(struct ipmi_smi *intf,
ipmb_seq, broadcast,
source_address, source_lun);
/* We will be getting a response in the BMC message queue. */
smi_msg->needs_response = true;
/*
* Copy the message into the recv message data, so we
* can retransmit it later if necessary.
@ -2176,7 +2210,6 @@ static int i_ipmi_request(struct ipmi_user *user,
goto out;
}
}
smi_msg->needs_response = false;
rcu_read_lock();
if (intf->in_shutdown) {
@ -3390,9 +3423,8 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
INIT_LIST_HEAD(&intf->xmit_msgs);
INIT_LIST_HEAD(&intf->hp_xmit_msgs);
spin_lock_init(&intf->events_lock);
spin_lock_init(&intf->watch_lock);
atomic_set(&intf->event_waiters, 0);
atomic_set(&intf->watchdog_waiters, 0);
atomic_set(&intf->command_waiters, 0);
intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
INIT_LIST_HEAD(&intf->waiting_events);
intf->waiting_events_count = 0;
@ -4408,8 +4440,6 @@ static void smi_recv_tasklet(unsigned long val)
}
}
smi_tell_to_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES, newmsg);
if (!run_to_completion)
spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
if (newmsg)
@ -4537,7 +4567,7 @@ static void check_msg_timeout(struct ipmi_smi *intf, struct seq_table *ent,
struct list_head *timeouts,
unsigned long timeout_period,
int slot, unsigned long *flags,
unsigned int *watch_mask)
bool *need_timer)
{
struct ipmi_recv_msg *msg;
@ -4549,13 +4579,14 @@ static void check_msg_timeout(struct ipmi_smi *intf, struct seq_table *ent,
if (timeout_period < ent->timeout) {
ent->timeout -= timeout_period;
*watch_mask |= IPMI_WATCH_MASK_CHECK_MESSAGES;
*need_timer = true;
return;
}
if (ent->retries_left == 0) {
/* The message has used all its retries. */
ent->inuse = 0;
smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
msg = ent->recv_msg;
list_add_tail(&msg->link, timeouts);
if (ent->broadcast)
@ -4568,7 +4599,7 @@ static void check_msg_timeout(struct ipmi_smi *intf, struct seq_table *ent,
struct ipmi_smi_msg *smi_msg;
/* More retries, send again. */
*watch_mask |= IPMI_WATCH_MASK_CHECK_MESSAGES;
*need_timer = true;
/*
* Start with the max timer, set to normal timer after
@ -4613,20 +4644,20 @@ static void check_msg_timeout(struct ipmi_smi *intf, struct seq_table *ent,
}
}
static unsigned int ipmi_timeout_handler(struct ipmi_smi *intf,
unsigned long timeout_period)
static bool ipmi_timeout_handler(struct ipmi_smi *intf,
unsigned long timeout_period)
{
struct list_head timeouts;
struct ipmi_recv_msg *msg, *msg2;
unsigned long flags;
int i;
unsigned int watch_mask = 0;
bool need_timer = false;
if (!intf->bmc_registered) {
kref_get(&intf->refcount);
if (!schedule_work(&intf->bmc_reg_work)) {
kref_put(&intf->refcount, intf_free);
watch_mask |= IPMI_WATCH_MASK_INTERNAL;
need_timer = true;
}
}
@ -4646,7 +4677,7 @@ static unsigned int ipmi_timeout_handler(struct ipmi_smi *intf,
for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++)
check_msg_timeout(intf, &intf->seq_table[i],
&timeouts, timeout_period, i,
&flags, &watch_mask);
&flags, &need_timer);
spin_unlock_irqrestore(&intf->seq_lock, flags);
list_for_each_entry_safe(msg, msg2, &timeouts, link)
@ -4677,7 +4708,7 @@ static unsigned int ipmi_timeout_handler(struct ipmi_smi *intf,
tasklet_schedule(&intf->recv_tasklet);
return watch_mask;
return need_timer;
}
static void ipmi_request_event(struct ipmi_smi *intf)
@ -4697,9 +4728,8 @@ static atomic_t stop_operation;
static void ipmi_timeout(struct timer_list *unused)
{
struct ipmi_smi *intf;
unsigned int watch_mask = 0;
bool need_timer = false;
int index;
unsigned long flags;
if (atomic_read(&stop_operation))
return;
@ -4712,28 +4742,14 @@ static void ipmi_timeout(struct timer_list *unused)
ipmi_request_event(intf);
intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
}
watch_mask |= IPMI_WATCH_MASK_INTERNAL;
need_timer = true;
}
if (atomic_read(&intf->watchdog_waiters))
watch_mask |= IPMI_WATCH_MASK_CHECK_WATCHDOG;
if (atomic_read(&intf->command_waiters))
watch_mask |= IPMI_WATCH_MASK_CHECK_COMMANDS;
watch_mask |= ipmi_timeout_handler(intf, IPMI_TIMEOUT_TIME);
spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
if (watch_mask != intf->last_watch_mask &&
intf->handlers->set_need_watch)
intf->handlers->set_need_watch(intf->send_info,
watch_mask);
intf->last_watch_mask = watch_mask;
spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
need_timer |= ipmi_timeout_handler(intf, IPMI_TIMEOUT_TIME);
}
srcu_read_unlock(&ipmi_interfaces_srcu, index);
if (watch_mask)
if (need_timer)
mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
}

2
drivers/char/ipmi/ipmi_si_intf.c
View File

@ -1066,7 +1066,7 @@ static void set_need_watch(void *send_info, unsigned int watch_mask)
unsigned long flags;
int enable;
enable = !!(watch_mask & ~IPMI_WATCH_MASK_INTERNAL);
enable = !!watch_mask;
atomic_set(&smi_info->need_watch, enable);
spin_lock_irqsave(&smi_info->si_lock, flags);

2
drivers/char/ipmi/ipmi_ssif.c
View File

@ -1129,7 +1129,7 @@ static void ssif_set_need_watch(void *send_info, unsigned int watch_mask)
if (watch_mask & IPMI_WATCH_MASK_CHECK_MESSAGES)
timeout = SSIF_WATCH_MSG_TIMEOUT;
else if (watch_mask & ~IPMI_WATCH_MASK_INTERNAL)
else if (watch_mask)
timeout = SSIF_WATCH_WATCHDOG_TIMEOUT;
flags = ipmi_ssif_lock_cond(ssif_info, &oflags);

17
include/linux/ipmi_smi.h
View File

@ -32,14 +32,11 @@ struct ipmi_smi;
/*
* Flags for set_check_watch() below. Tells if the SMI should be
* waiting for watchdog timeouts, commands and/or messages. There is
* also an internal flag for the message handler, SMIs should ignore
* it.
* waiting for watchdog timeouts, commands and/or messages.
*/
#define IPMI_WATCH_MASK_INTERNAL (1 << 0)
#define IPMI_WATCH_MASK_CHECK_MESSAGES (1 << 1)
#define IPMI_WATCH_MASK_CHECK_WATCHDOG (1 << 2)
#define IPMI_WATCH_MASK_CHECK_COMMANDS (1 << 3)
#define IPMI_WATCH_MASK_CHECK_MESSAGES (1 << 0)
#define IPMI_WATCH_MASK_CHECK_WATCHDOG (1 << 1)
#define IPMI_WATCH_MASK_CHECK_COMMANDS (1 << 2)
/*
* Messages to/from the lower layer. The smi interface will take one
@ -66,12 +63,6 @@ struct ipmi_smi_msg {
int rsp_size;
unsigned char rsp[IPMI_MAX_MSG_LENGTH];
/*
* There should be a response message coming back in the BMC
* message queue.
*/
bool needs_response;
/*
* Will be called when the system is done with the message
* (presumably to free it).