[PATCH net-next 3/9] s390/qeth: unify the tracking of active cmds on ccw device

Julian Wiedmann
2021-06-11T07:33:59Z

We have one field to track _whether_ a cmd is active on a ccw device
('irq_pending'), and one to track _which_ cmd it is ('active_cmd').

Get rid of the irq_pending field, by testing active_cmd for NULL.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
---
drivers/s390/net/qeth_core.h | 14 +++++++-------
drivers/s390/net/qeth_core_main.c | 12 ++++--------
2 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index 4d29801bcf41..ad0e86aa99b2 100644
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -614,7 +614,6 @@ struct qeth_channel {
struct ccw_device *ccwdev;
struct qeth_cmd_buffer *active_cmd;
enum qeth_channel_states state;
- atomic_t irq_pending;
};

struct qeth_reply {
@@ -664,11 +663,6 @@ static inline struct ccw1 *__ccw_from_cmd(struct qeth_cmd_buffer *iob)
return (struct ccw1 *)(iob->data + ALIGN(iob->length, 8));
}

-static inline bool qeth_trylock_channel(struct qeth_channel *channel)
-{
- return atomic_cmpxchg(&channel->irq_pending, 0, 1) == 0;
-}
-
/**
* OSA card related definitions
*/
@@ -896,10 +890,16 @@ static inline bool qeth_use_tx_irqs(struct qeth_card *card)
static inline void qeth_unlock_channel(struct qeth_card *card,
struct qeth_channel *channel)
{
- atomic_set(&channel->irq_pending, 0);
+ xchg(&channel->active_cmd, NULL);
wake_up(&card->wait_q);
}

+static inline bool qeth_trylock_channel(struct qeth_channel *channel,
+ struct qeth_cmd_buffer *cmd)
+{
+ return cmpxchg(&channel->active_cmd, NULL, cmd) == NULL;
+}
+
struct qeth_trap_id {
__u16 lparnr;
char vmname[8];
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index f22f223a4a6c..83d540f8b527 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -1268,7 +1268,6 @@ static void qeth_irq(struct ccw_device *cdev, unsigned long intparm,
iob = (struct qeth_cmd_buffer *) (addr_t)intparm;
}

- channel->active_cmd = NULL;
qeth_unlock_channel(card, channel);

rc = qeth_check_irb_error(card, cdev, irb);
@@ -1715,11 +1714,10 @@ static int qeth_stop_channel(struct qeth_channel *channel)
rc = ccw_device_set_offline(cdev);

spin_lock_irq(get_ccwdev_lock(cdev));
- if (channel->active_cmd) {
+ if (channel->active_cmd)
dev_err(&cdev->dev, "Stopped channel while cmd %px was still active\n",
channel->active_cmd);
- channel->active_cmd = NULL;
- }
+
cdev->handler = NULL;
spin_unlock_irq(get_ccwdev_lock(cdev));

@@ -1732,7 +1730,7 @@ static int qeth_start_channel(struct qeth_channel *channel)
int rc;

channel->state = CH_STATE_DOWN;
- atomic_set(&channel->irq_pending, 0);
+ xchg(&channel->active_cmd, NULL);

spin_lock_irq(get_ccwdev_lock(cdev));
cdev->handler = qeth_irq;
@@ -2039,7 +2037,7 @@ static int qeth_send_control_data(struct qeth_card *card,
reply->param = reply_param;

timeout = wait_event_interruptible_timeout(card->wait_q,
- qeth_trylock_channel(channel),
+ qeth_trylock_channel(channel, iob),
timeout);
if (timeout <= 0) {
qeth_put_cmd(iob);
@@ -2059,8 +2057,6 @@ static int qeth_send_control_data(struct qeth_card *card,
spin_lock_irq(get_ccwdev_lock(channel->ccwdev));
rc = ccw_device_start_timeout(channel->ccwdev, __ccw_from_cmd(iob),
(addr_t) iob, 0, 0, timeout);
- if (!rc)
- channel->active_cmd = iob;
spin_unlock_irq(get_ccwdev_lock(channel->ccwdev));
if (rc) {
QETH_DBF_MESSAGE(2, "qeth_send_control_data on device %x: ccw_device_start rc = %i\n",
--
2.25.1