Commit 71457d48 authored by Christian Gromm's avatar Christian Gromm Committed by Greg Kroah-Hartman
Browse files

staging: most: add fair buffer distribution 



This patch ensures a fair distribution of buffers, when two AIMs share a
single channel. The AIMs then won't be able to use more than half of all
pre-allocated buffers of the linked channel. However, in case the channel
is not shared, the AIM can exclusively use all available buffers.

Signed-off-by: default avatarAndrey Shvetsov <andrey.shvetsov@k2l.de>
Signed-off-by: default avatarChristian Gromm <christian.gromm@microchip.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c81c9c3e

drivers/staging/most/aim-cdev/cdev.c

+3 −2
Original line number Diff line number Diff line
@@ -165,7 +165,7 @@ static ssize_t aim_write(struct file *filp, const char __user *buf, 
	}

	mutex_unlock(&channel->io_mutex);



	mbo = most_get_mbo(channel->iface, channel->channel_id);

	mbo = most_get_mbo(channel->iface, channel->channel_id, &cdev_aim);



	if (!mbo) {

		if ((filp->f_flags & O_NONBLOCK))
@@ -173,7 +173,8 @@ static ssize_t aim_write(struct file *filp, const char __user *buf, 
		if (wait_event_interruptible(

			    channel->wq,

			    (mbo = most_get_mbo(channel->iface,

						channel->channel_id)) ||

						channel->channel_id,

						&cdev_aim)) ||

			    (!channel->dev)))

			return -ERESTARTSYS;

	}

drivers/staging/most/aim-network/networking.c

+1 −1
Original line number Diff line number Diff line
@@ -245,7 +245,7 @@ static netdev_tx_t most_nd_start_xmit(struct sk_buff *skb, 


	BUG_ON(nd->dev != dev);



	mbo = most_get_mbo(nd->iface, nd->tx.ch_id);

	mbo = most_get_mbo(nd->iface, nd->tx.ch_id, &aim);



	if (!mbo) {

		netif_stop_queue(dev);

drivers/staging/most/aim-sound/sound.c

+2 −1
Original line number Diff line number Diff line
@@ -251,7 +251,8 @@ static int playback_thread(void *data) 
		wait_event_interruptible(

			channel->playback_waitq,

			kthread_should_stop() ||

			(mbo = most_get_mbo(channel->iface, channel->id)));

			(mbo = most_get_mbo(channel->iface, channel->id,

					    &audio_aim)));



		if (!mbo)

			continue;

drivers/staging/most/hdm-dim2/dim2_hdm.c

+1 −1
Original line number Diff line number Diff line
@@ -669,7 +669,7 @@ static void request_netinfo(struct most_interface *most_iface, int ch_idx) 
		return;

	}



	mbo = most_get_mbo(&dev->most_iface, dev->atx_idx);

	mbo = most_get_mbo(&dev->most_iface, dev->atx_idx, NULL);

	if (!mbo)

		return;

drivers/staging/most/mostcore/core.c

+26 −1
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ static struct class *most_class; 
static struct device *class_glue_dir;

static struct ida mdev_id;

static int modref;

static int dummy_num_buffers;



struct most_c_obj {

	struct kobject kobj;
@@ -59,6 +60,8 @@ struct most_c_obj { 
	struct most_aim *second_aim;

	int first_aim_refs;

	int second_aim_refs;

	int first_num_buffers;

	int second_num_buffers;

	struct list_head trash_fifo;

	struct task_struct *hdm_enqueue_task;

	struct mutex stop_task_mutex;
@@ -1233,6 +1236,7 @@ static void arm_mbo(struct mbo *mbo) 
	}



	spin_lock_irqsave(&c->fifo_lock, flags);

	++*mbo->num_buffers_ptr;

	list_add_tail(&mbo->list, &c->fifo);

	spin_unlock_irqrestore(&c->fifo_lock, flags);
@@ -1286,6 +1290,7 @@ static int arm_mbo_chain(struct most_c_obj *c, int dir, 
			goto _error1;

		}

		mbo->complete = compl;

		mbo->num_buffers_ptr = &dummy_num_buffers;

		if (dir == MOST_CH_RX) {

			nq_hdm_mbo(mbo);

			atomic_inc(&c->mbo_nq_level);
@@ -1384,22 +1389,40 @@ most_c_obj *get_channel_by_iface(struct most_interface *iface, int id) 
 * This attempts to get a free buffer out of the channel fifo.

 * Returns a pointer to MBO on success or NULL otherwise.

 */

struct mbo *most_get_mbo(struct most_interface *iface, int id)

struct mbo *most_get_mbo(struct most_interface *iface, int id,

			 struct most_aim *aim)

{

	struct mbo *mbo;

	struct most_c_obj *c;

	unsigned long flags;

	int *num_buffers_ptr;



	c = get_channel_by_iface(iface, id);

	if (unlikely(!c))

		return NULL;



	if (c->first_aim_refs && c->second_aim_refs &&

	    ((aim == c->first_aim && c->first_num_buffers <= 0) ||

	     (aim == c->second_aim && c->second_num_buffers <= 0)))

		return NULL;



	if (aim == c->first_aim)

		num_buffers_ptr = &c->first_num_buffers;

	else if (aim == c->second_aim)

		num_buffers_ptr = &c->second_num_buffers;

	else

		num_buffers_ptr = &dummy_num_buffers;



	spin_lock_irqsave(&c->fifo_lock, flags);

	if (list_empty(&c->fifo)) {

		spin_unlock_irqrestore(&c->fifo_lock, flags);

		return NULL;

	}

	mbo = list_pop_mbo(&c->fifo);

	--*num_buffers_ptr;

	spin_unlock_irqrestore(&c->fifo_lock, flags);



	mbo->num_buffers_ptr = num_buffers_ptr;

	mbo->buffer_length = c->cfg.buffer_size;

	return mbo;

}
@@ -1530,6 +1553,8 @@ int most_start_channel(struct most_interface *iface, int id, 
		goto error;



	c->is_starving = 0;

	c->first_num_buffers = c->cfg.num_buffers / 2;

	c->second_num_buffers = c->cfg.num_buffers - c->first_num_buffers;

	atomic_set(&c->mbo_ref, num_buffer);



out: