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Commit 76663f56 authored by Chris Lew's avatar Chris Lew
Browse files

net: qrtr: mhi: Create list for pending ul transfers 



QRTR does not serialize sends like the dl path. Create a list of
pending transactions so multiple transfers can happen at the same time
without corruption. If there is a sock attached to the skb, take a
reference to the sock. This prevents the sock from being released while
waiting for the ul callback from MHI.

Change-Id: I2d9359ec616497f3dda4f2762d142cdd33796a88
Signed-off-by: default avatarChris Lew <clew@codeaurora.org>
parent f6fbeafa

net/qrtr/mhi.c

+62 −17
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/skbuff.h>

#include <linux/mod_devicetable.h>

#include <linux/mhi.h>

#include <net/sock.h>



#include "qrtr.h"
@@ -21,9 +22,29 @@ struct qrtr_mhi_dev { 
	struct qrtr_endpoint ep;

	struct mhi_device *mhi_dev;

	struct device *dev;

	struct completion ul_done;

	spinlock_t ul_lock;		/* lock to protect ul_pkts */

	struct list_head ul_pkts;

};



struct qrtr_mhi_pkt {

	struct list_head node;

	struct sk_buff *skb;

	struct kref refcount;

	struct completion done;

};



static void qrtr_mhi_pkt_release(struct kref *ref)

{

	struct qrtr_mhi_pkt *pkt = container_of(ref, struct qrtr_mhi_pkt,

						refcount);

	struct sock *sk = pkt->skb->sk;



	consume_skb(pkt->skb);

	if (sk)

		sock_put(sk);

	kfree(pkt);

}



/* from mhi to qrtr */

static void qcom_mhi_qrtr_dl_callback(struct mhi_device *mhi_dev,

				      struct mhi_result *mhi_res)
@@ -45,39 +66,63 @@ static void qcom_mhi_qrtr_ul_callback(struct mhi_device *mhi_dev, 
				      struct mhi_result *mhi_res)

{

	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);

	struct sk_buff *skb = mhi_res->buf_addr;

	struct qrtr_mhi_pkt *pkt;



	if (!mhi_res->transaction_status) {

		complete(&qdev->ul_done);

		consume_skb(skb);

	} else {

		kfree_skb(skb);

	}

	spin_lock_bh(&qdev->ul_lock);

	pkt = list_first_entry(&qdev->ul_pkts, struct qrtr_mhi_pkt, node);

	list_del(&pkt->node);

	complete_all(&pkt->done);



	kref_put(&pkt->refcount, qrtr_mhi_pkt_release);

	spin_unlock_bh(&qdev->ul_lock);

}



/* from qrtr to mhi */

static int qcom_mhi_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb)

{

	struct qrtr_mhi_dev *qdev = container_of(ep, struct qrtr_mhi_dev, ep);

	struct qrtr_mhi_pkt *pkt;

	int rc;



	rc = skb_linearize(skb);

	if (rc)

		goto out;

	if (rc) {

		kfree_skb(skb);

		return rc;

	}



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

	if (!pkt) {

		kfree_skb(skb);

		return -ENOMEM;

	}



	reinit_completion(&qdev->ul_done);

	init_completion(&pkt->done);

	kref_init(&pkt->refcount);

	kref_get(&pkt->refcount);

	pkt->skb = skb;



	spin_lock_bh(&qdev->ul_lock);

	list_add_tail(&pkt->node, &qdev->ul_pkts);

	rc = mhi_queue_transfer(qdev->mhi_dev, DMA_TO_DEVICE, skb, skb->len,

				MHI_EOT);

	if (rc)

		goto out;

	if (rc) {

		list_del(&pkt->node);

		kfree_skb(skb);

		kfree(pkt);

		spin_unlock_bh(&qdev->ul_lock);

		return rc;

	}

	spin_unlock_bh(&qdev->ul_lock);

	if (skb->sk)

		sock_hold(skb->sk);



	rc = wait_for_completion_interruptible_timeout(&qdev->ul_done, HZ * 5);

	rc = wait_for_completion_interruptible_timeout(&pkt->done, HZ * 5);

	if (rc > 0)

		rc = 0;

	else if (rc == 0)

		rc = -ETIMEDOUT;



out:

	kref_put(&pkt->refcount, qrtr_mhi_pkt_release);

	return rc;

}
@@ -95,7 +140,8 @@ static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev, 
	qdev->dev = &mhi_dev->dev;

	qdev->ep.xmit = qcom_mhi_qrtr_send;



	init_completion(&qdev->ul_done);

	INIT_LIST_HEAD(&qdev->ul_pkts);

	spin_lock_init(&qdev->ul_lock);



	rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);

	if (rc)
@@ -113,7 +159,6 @@ static void qcom_mhi_qrtr_remove(struct mhi_device *mhi_dev) 
	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);



	qrtr_endpoint_unregister(&qdev->ep);

	complete(&qdev->ul_done);

	dev_set_drvdata(&mhi_dev->dev, NULL);

}