Commit 8f5de6fb authored by Xabier Marquiegui's avatar Xabier Marquiegui Committed by David S. Miller
Browse files

ptp: support multiple timestamp event readers 



Use linked lists to create one event queue per open file. This enables
simultaneous readers for timestamp event queues.

Signed-off-by: default avatarXabier Marquiegui <reibax@gmail.com>
Suggested-by: default avatarRichard Cochran <richardcochran@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d26ab5a3

drivers/ptp/ptp_chardev.c

+49 −19
Original line number Diff line number Diff line
@@ -103,6 +103,31 @@ int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin, 


int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)

{

	struct ptp_clock *ptp =

		container_of(pccontext->clk, struct ptp_clock, clock);

	struct timestamp_event_queue *queue;



	queue = kzalloc(sizeof(*queue), GFP_KERNEL);

	if (!queue)

		return -EINVAL;

	spin_lock_init(&queue->lock);

	list_add_tail(&queue->qlist, &ptp->tsevqs);

	pccontext->private_clkdata = queue;

	return 0;

}



int ptp_release(struct posix_clock_context *pccontext)

{

	struct timestamp_event_queue *queue = pccontext->private_clkdata;

	unsigned long flags;



	if (queue) {

		pccontext->private_clkdata = NULL;

		spin_lock_irqsave(&queue->lock, flags);

		list_del(&queue->qlist);

		spin_unlock_irqrestore(&queue->lock, flags);

		kfree(queue);

	}

	return 0;

}
@@ -441,10 +466,11 @@ __poll_t ptp_poll(struct posix_clock_context *pccontext, struct file *fp, 
		container_of(pccontext->clk, struct ptp_clock, clock);

	struct timestamp_event_queue *queue;



	poll_wait(fp, &ptp->tsev_wq, wait);

	queue = pccontext->private_clkdata;

	if (!queue)

		return EPOLLERR;



	/* Extract only the first element in the queue list */

	queue = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue, qlist);

	poll_wait(fp, &ptp->tsev_wq, wait);



	return queue_cnt(queue) ? EPOLLIN : 0;

}
@@ -462,36 +488,36 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags, 
	size_t qcnt, i;

	int result;



	/* Extract only the first element in the queue list */

	queue = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,

				 qlist);

	queue = pccontext->private_clkdata;

	if (!queue) {

		result = -EINVAL;

		goto exit;

	}



	if (cnt % sizeof(struct ptp_extts_event) != 0)

		return -EINVAL;

	if (cnt % sizeof(struct ptp_extts_event) != 0) {

		result = -EINVAL;

		goto exit;

	}



	if (cnt > EXTTS_BUFSIZE)

		cnt = EXTTS_BUFSIZE;



	cnt = cnt / sizeof(struct ptp_extts_event);



	if (mutex_lock_interruptible(&ptp->tsevq_mux))

		return -ERESTARTSYS;



	if (wait_event_interruptible(ptp->tsev_wq,

				     ptp->defunct || queue_cnt(queue))) {

		mutex_unlock(&ptp->tsevq_mux);

		return -ERESTARTSYS;

	}



	if (ptp->defunct) {

		mutex_unlock(&ptp->tsevq_mux);

		return -ENODEV;

		result = -ENODEV;

		goto exit;

	}



	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);

	if (!event) {

		mutex_unlock(&ptp->tsevq_mux);

		return -ENOMEM;

		result = -ENOMEM;

		goto exit;

	}



	spin_lock_irqsave(&queue->lock, flags);
@@ -510,12 +536,16 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags, 


	cnt = cnt * sizeof(struct ptp_extts_event);



	mutex_unlock(&ptp->tsevq_mux);



	result = cnt;

	if (copy_to_user(buf, event, cnt))

	if (copy_to_user(buf, event, cnt)) {

		result = -EFAULT;

		goto free_event;

	}



free_event:

	kfree(event);

exit:

	if (result < 0)

		ptp_release(pccontext);

	return result;

}

drivers/ptp/ptp_clock.c

+2 −4
Original line number Diff line number Diff line
@@ -162,6 +162,7 @@ static struct posix_clock_operations ptp_clock_ops = { 
	.clock_settime	= ptp_clock_settime,

	.ioctl		= ptp_ioctl,

	.open		= ptp_open,

	.release	= ptp_release,

	.poll		= ptp_poll,

	.read		= ptp_read,

};
@@ -174,7 +175,6 @@ static void ptp_clock_release(struct device *dev) 


	ptp_cleanup_pin_groups(ptp);

	kfree(ptp->vclock_index);

	mutex_destroy(&ptp->tsevq_mux);

	mutex_destroy(&ptp->pincfg_mux);

	mutex_destroy(&ptp->n_vclocks_mux);

	/* Delete first entry */
@@ -242,9 +242,8 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, 
	queue = kzalloc(sizeof(*queue), GFP_KERNEL);

	if (!queue)

		goto no_memory_queue;

	spin_lock_init(&queue->lock);

	list_add_tail(&queue->qlist, &ptp->tsevqs);

	mutex_init(&ptp->tsevq_mux);

	spin_lock_init(&queue->lock);

	mutex_init(&ptp->pincfg_mux);

	mutex_init(&ptp->n_vclocks_mux);

	init_waitqueue_head(&ptp->tsev_wq);
@@ -345,7 +344,6 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, 
	if (ptp->kworker)

		kthread_destroy_worker(ptp->kworker);

kworker_err:

	mutex_destroy(&ptp->tsevq_mux);

	mutex_destroy(&ptp->pincfg_mux);

	mutex_destroy(&ptp->n_vclocks_mux);

	list_del(&queue->qlist);

drivers/ptp/ptp_private.h

+0 −1
Original line number Diff line number Diff line
@@ -38,7 +38,6 @@ struct ptp_clock { 
	struct pps_device *pps_source;

	long dialed_frequency; /* remembers the frequency adjustment */

	struct list_head tsevqs; /* timestamp fifo list */

	struct mutex tsevq_mux; /* one process at a time reading the fifo */

	struct mutex pincfg_mux; /* protect concurrent info->pin_config access */

	wait_queue_head_t tsev_wq;

	int defunct; /* tells readers to go away when clock is being removed */

drivers/ptp/ptp_sysfs.c

+4 −5
Original line number Diff line number Diff line
@@ -81,15 +81,15 @@ static ssize_t extts_fifo_show(struct device *dev, 
	size_t qcnt;

	int cnt = 0;



	cnt = list_count_nodes(&ptp->tsevqs);

	if (cnt <= 0)

		goto out;



	/* The sysfs fifo will always draw from the fist queue */

	queue = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,

				 qlist);



	memset(&event, 0, sizeof(event));



	if (mutex_lock_interruptible(&ptp->tsevq_mux))

		return -ERESTARTSYS;



	spin_lock_irqsave(&queue->lock, flags);

	qcnt = queue_cnt(queue);

	if (qcnt) {
@@ -104,7 +104,6 @@ static ssize_t extts_fifo_show(struct device *dev, 
	cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n",

		       event.index, event.t.sec, event.t.nsec);

out:

	mutex_unlock(&ptp->tsevq_mux);

	return cnt;

}

static DEVICE_ATTR(fifo, 0444, extts_fifo_show, NULL);