[PATCH 4.9 24/28] s390/qeth: lock read device while queueing next buffer
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2018-03-29 18:00:43
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4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Julian Wiedmann <redacted> [ Upstream commit 17bf8c9b3d499d5168537c98b61eb7a1fcbca6c2 ] For calling ccw_device_start(), issue_next_read() needs to hold the device's ccwlock. This is satisfied for the IRQ handler path (where qeth_irq() gets called under the ccwlock), but we need explicit locking for the initial call by the MPC initialization. Signed-off-by: Julian Wiedmann <redacted> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/s390/net/qeth_core_main.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c@@ -522,8 +522,7 @@ static inline int qeth_is_cq(struct qeth queue == card->qdio.no_in_queues - 1; } - -static int qeth_issue_next_read(struct qeth_card *card) +static int __qeth_issue_next_read(struct qeth_card *card) { int rc; struct qeth_cmd_buffer *iob;
@@ -554,6 +553,17 @@ static int qeth_issue_next_read(struct q return rc; } +static int qeth_issue_next_read(struct qeth_card *card) +{ + int ret; + + spin_lock_irq(get_ccwdev_lock(CARD_RDEV(card))); + ret = __qeth_issue_next_read(card); + spin_unlock_irq(get_ccwdev_lock(CARD_RDEV(card))); + + return ret; +} + static struct qeth_reply *qeth_alloc_reply(struct qeth_card *card) { struct qeth_reply *reply;
@@ -1179,7 +1189,7 @@ static void qeth_irq(struct ccw_device * return; if (channel == &card->read && channel->state == CH_STATE_UP) - qeth_issue_next_read(card); + __qeth_issue_next_read(card); iob = channel->iob; index = channel->buf_no;