From: Julian Wiedmann <jwi@linux.ibm.com>
Subject: s390/qeth: uninstall IRQ handler on device removal
Patch-mainline: v4.20-rc1
Git-commit: 121ca39aa5585def682a2c8592983442438b84dc
References: FATE#326377, LTC#169210, bsc#1115382

Summary:        qeth: Full-blown TCP Segmentation Offload
Description:    As of now, qeth only supports TCP Segmentation Offload (TSO)
                for IPv4 in Layer3 devices. This feature extends the existing
                support to IPv6, and adds support for TSO in both IP variants
                for Layer2.

                To cleanly pull in all the necessary changes to the transmit
                code, update the qeth driver to the current 4.20 level.


Upstream-Description:

             s390/qeth: uninstall IRQ handler on device removal

             When setting up, qeth installs its IRQ handler on the ccw devices. But
             the IRQ handler is not cleared on removal - so even after qeth yields
             control of the ccw devices, spurious interrupts would still be presented
             to us.

             Make (de-)installation of the IRQ handler part of the ccw channel
             setup/removal helpers, and while at it also add the appropriate locking.
             Shift around qeth_setup_channel() to avoid a forward declaration for
             qeth_irq().

             Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
             Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/s390/net/qeth_core_main.c |  102 ++++++++++++++++++++------------------
 1 file changed, 54 insertions(+), 48 deletions(-)

--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -899,44 +899,6 @@ out:
 	qeth_release_buffer(channel, iob);
 }
 
-static int qeth_setup_channel(struct qeth_channel *channel, bool alloc_buffers)
-{
-	int cnt;
-
-	QETH_DBF_TEXT(SETUP, 2, "setupch");
-
-	channel->ccw = kmalloc(sizeof(struct ccw1), GFP_KERNEL | GFP_DMA);
-	if (!channel->ccw)
-		return -ENOMEM;
-	channel->state = CH_STATE_DOWN;
-	atomic_set(&channel->irq_pending, 0);
-	init_waitqueue_head(&channel->wait_q);
-
-	if (!alloc_buffers)
-		return 0;
-
-	for (cnt = 0; cnt < QETH_CMD_BUFFER_NO; cnt++) {
-		channel->iob[cnt].data =
-			kzalloc(QETH_BUFSIZE, GFP_DMA|GFP_KERNEL);
-		if (channel->iob[cnt].data == NULL)
-			break;
-		channel->iob[cnt].state = BUF_STATE_FREE;
-		channel->iob[cnt].channel = channel;
-		channel->iob[cnt].callback = qeth_send_control_data_cb;
-		channel->iob[cnt].rc = 0;
-	}
-	if (cnt < QETH_CMD_BUFFER_NO) {
-		kfree(channel->ccw);
-		while (cnt-- > 0)
-			kfree(channel->iob[cnt].data);
-		return -ENOMEM;
-	}
-	channel->io_buf_no = 0;
-	spin_lock_init(&channel->iob_lock);
-
-	return 0;
-}
-
 static int qeth_set_thread_start_bit(struct qeth_card *card,
 		unsigned long thread)
 {
@@ -1335,14 +1297,61 @@ static void qeth_free_buffer_pool(struct
 
 static void qeth_clean_channel(struct qeth_channel *channel)
 {
+	struct ccw_device *cdev = channel->ccwdev;
 	int cnt;
 
 	QETH_DBF_TEXT(SETUP, 2, "freech");
+
+	spin_lock_irq(get_ccwdev_lock(cdev));
+	cdev->handler = NULL;
+	spin_unlock_irq(get_ccwdev_lock(cdev));
+
 	for (cnt = 0; cnt < QETH_CMD_BUFFER_NO; cnt++)
 		kfree(channel->iob[cnt].data);
 	kfree(channel->ccw);
 }
 
+static int qeth_setup_channel(struct qeth_channel *channel, bool alloc_buffers)
+{
+	struct ccw_device *cdev = channel->ccwdev;
+	int cnt;
+
+	QETH_DBF_TEXT(SETUP, 2, "setupch");
+
+	channel->ccw = kmalloc(sizeof(struct ccw1), GFP_KERNEL | GFP_DMA);
+	if (!channel->ccw)
+		return -ENOMEM;
+	channel->state = CH_STATE_DOWN;
+	atomic_set(&channel->irq_pending, 0);
+	init_waitqueue_head(&channel->wait_q);
+
+	spin_lock_irq(get_ccwdev_lock(cdev));
+	cdev->handler = qeth_irq;
+	spin_unlock_irq(get_ccwdev_lock(cdev));
+
+	if (!alloc_buffers)
+		return 0;
+
+	for (cnt = 0; cnt < QETH_CMD_BUFFER_NO; cnt++) {
+		channel->iob[cnt].data =
+			kzalloc(QETH_BUFSIZE, GFP_DMA|GFP_KERNEL);
+		if (channel->iob[cnt].data == NULL)
+			break;
+		channel->iob[cnt].state = BUF_STATE_FREE;
+		channel->iob[cnt].channel = channel;
+		channel->iob[cnt].callback = qeth_send_control_data_cb;
+		channel->iob[cnt].rc = 0;
+	}
+	if (cnt < QETH_CMD_BUFFER_NO) {
+		qeth_clean_channel(channel);
+		return -ENOMEM;
+	}
+	channel->io_buf_no = 0;
+	spin_lock_init(&channel->iob_lock);
+
+	return 0;
+}
+
 static void qeth_set_single_write_queues(struct qeth_card *card)
 {
 	if ((atomic_read(&card->qdio.state) != QETH_QDIO_UNINITIALIZED) &&
@@ -1493,7 +1502,7 @@ static void qeth_core_sl_print(struct se
 			CARD_BUS_ID(card), card->info.mcl_level);
 }
 
-static struct qeth_card *qeth_alloc_card(void)
+static struct qeth_card *qeth_alloc_card(struct ccwgroup_device *gdev)
 {
 	struct qeth_card *card;
 
@@ -1502,6 +1511,11 @@ static struct qeth_card *qeth_alloc_card
 	if (!card)
 		goto out;
 	QETH_DBF_HEX(SETUP, 2, &card, sizeof(void *));
+
+	card->gdev = gdev;
+	CARD_RDEV(card) = gdev->cdev[0];
+	CARD_WDEV(card) = gdev->cdev[1];
+	CARD_DDEV(card) = gdev->cdev[2];
 	if (qeth_setup_channel(&card->read, true))
 		goto out_ip;
 	if (qeth_setup_channel(&card->write, true))
@@ -5768,7 +5782,7 @@ static int qeth_core_probe_device(struct
 
 	QETH_DBF_TEXT_(SETUP, 2, "%s", dev_name(&gdev->dev));
 
-	card = qeth_alloc_card();
+	card = qeth_alloc_card(gdev);
 	if (!card) {
 		QETH_DBF_TEXT_(SETUP, 2, "1err%d", -ENOMEM);
 		rc = -ENOMEM;
@@ -5784,15 +5798,7 @@ static int qeth_core_probe_device(struct
 			goto err_card;
 	}
 
-	card->read.ccwdev  = gdev->cdev[0];
-	card->write.ccwdev = gdev->cdev[1];
-	card->data.ccwdev  = gdev->cdev[2];
 	dev_set_drvdata(&gdev->dev, card);
-	card->gdev = gdev;
-	gdev->cdev[0]->handler = qeth_irq;
-	gdev->cdev[1]->handler = qeth_irq;
-	gdev->cdev[2]->handler = qeth_irq;
-
 	qeth_setup_card(card);
 	qeth_update_from_chp_desc(card);