Commit a9b5bb5c authored by Allen Pais's avatar Allen Pais Committed by Corey Minyard
Browse files

ipmi: Convert from tasklet to BH workqueue 

The only generic interface to execute asynchronously in the BH context is
tasklet; however, it's marked deprecated and has some design flaws. To
replace tasklets, BH workqueue support was recently added. A BH workqueue
behaves similarly to regular workqueues except that the queued work items
are executed in the BH context.

This patch converts drivers/char/ipmi/* from tasklet to BH workqueue.

Based on the work done by Tejun Heo <tj@kernel.org>
Branch: https://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git

 for-6.10

Signed-off-by: default avatarAllen Pais <allen.lkml@gmail.com>
Message-Id: <20240327160314.9982-7-apais@linux.microsoft.com>
[Removed a duplicate include of workqueue.h]
Signed-off-by: default avatarCorey Minyard <minyard@acm.org>
parent 8d025e20

drivers/char/ipmi/ipmi_msghandler.c

+14 −15
Original line number Diff line number Diff line
@@ -41,7 +41,7 @@ 


static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void);

static int ipmi_init_msghandler(void);

static void smi_recv_tasklet(struct tasklet_struct *t);

static void smi_recv_work(struct work_struct *t);

static void handle_new_recv_msgs(struct ipmi_smi *intf);

static void need_waiter(struct ipmi_smi *intf);

static int handle_one_recv_msg(struct ipmi_smi *intf,
@@ -498,13 +498,13 @@ struct ipmi_smi { 
	/*

	 * Messages queued for delivery.  If delivery fails (out of memory

	 * for instance), They will stay in here to be processed later in a

	 * periodic timer interrupt.  The tasklet is for handling received

	 * periodic timer interrupt.  The workqueue is for handling received

	 * messages directly from the handler.

	 */

	spinlock_t       waiting_rcv_msgs_lock;

	struct list_head waiting_rcv_msgs;

	atomic_t	 watchdog_pretimeouts_to_deliver;

	struct tasklet_struct recv_tasklet;

	struct work_struct recv_work;



	spinlock_t             xmit_msgs_lock;

	struct list_head       xmit_msgs;
@@ -704,7 +704,7 @@ static void clean_up_interface_data(struct ipmi_smi *intf) 
	struct cmd_rcvr  *rcvr, *rcvr2;

	struct list_head list;



	tasklet_kill(&intf->recv_tasklet);

	cancel_work_sync(&intf->recv_work);



	free_smi_msg_list(&intf->waiting_rcv_msgs);

	free_recv_msg_list(&intf->waiting_events);
@@ -1319,7 +1319,7 @@ static void free_user(struct kref *ref) 
{

	struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount);



	/* SRCU cleanup must happen in task context. */

	/* SRCU cleanup must happen in workqueue context. */

	queue_work(remove_work_wq, &user->remove_work);

}
@@ -3605,8 +3605,7 @@ int ipmi_add_smi(struct module *owner, 
	intf->curr_seq = 0;

	spin_lock_init(&intf->waiting_rcv_msgs_lock);

	INIT_LIST_HEAD(&intf->waiting_rcv_msgs);

	tasklet_setup(&intf->recv_tasklet,

		     smi_recv_tasklet);

	INIT_WORK(&intf->recv_work, smi_recv_work);

	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 0);

	spin_lock_init(&intf->xmit_msgs_lock);

	INIT_LIST_HEAD(&intf->xmit_msgs);
@@ -4779,7 +4778,7 @@ static void handle_new_recv_msgs(struct ipmi_smi *intf) 
			 * To preserve message order, quit if we

			 * can't handle a message.  Add the message

			 * back at the head, this is safe because this

			 * tasklet is the only thing that pulls the

			 * workqueue is the only thing that pulls the

			 * messages.

			 */

			list_add(&smi_msg->link, &intf->waiting_rcv_msgs);
@@ -4812,10 +4811,10 @@ static void handle_new_recv_msgs(struct ipmi_smi *intf) 
	}

}



static void smi_recv_tasklet(struct tasklet_struct *t)

static void smi_recv_work(struct work_struct *t)

{

	unsigned long flags = 0; /* keep us warning-free. */

	struct ipmi_smi *intf = from_tasklet(intf, t, recv_tasklet);

	struct ipmi_smi *intf = from_work(intf, t, recv_work);

	int run_to_completion = intf->run_to_completion;

	struct ipmi_smi_msg *newmsg = NULL;
@@ -4866,7 +4865,7 @@ void ipmi_smi_msg_received(struct ipmi_smi *intf, 


	/*

	 * To preserve message order, we keep a queue and deliver from

	 * a tasklet.

	 * a workqueue.

	 */

	if (!run_to_completion)

		spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
@@ -4887,9 +4886,9 @@ void ipmi_smi_msg_received(struct ipmi_smi *intf, 
		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);



	if (run_to_completion)

		smi_recv_tasklet(&intf->recv_tasklet);

		smi_recv_work(&intf->recv_work);

	else

		tasklet_schedule(&intf->recv_tasklet);

		queue_work(system_bh_wq, &intf->recv_work);

}

EXPORT_SYMBOL(ipmi_smi_msg_received);
@@ -4899,7 +4898,7 @@ void ipmi_smi_watchdog_pretimeout(struct ipmi_smi *intf) 
		return;



	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 1);

	tasklet_schedule(&intf->recv_tasklet);

	queue_work(system_bh_wq, &intf->recv_work);

}

EXPORT_SYMBOL(ipmi_smi_watchdog_pretimeout);
@@ -5068,7 +5067,7 @@ static bool ipmi_timeout_handler(struct ipmi_smi *intf, 
				       flags);

	}



	tasklet_schedule(&intf->recv_tasklet);

	queue_work(system_bh_wq, &intf->recv_work);



	return need_timer;

}