We statically allocate 8 cmd buffers on the read channel, when the only
IO left that's still using them is the long-running READ.
Replace this with a single allocated cmd, that gets restarted whenever
the READ completed.
This introduces refcounting for allocated cmds, so that the READ cmd can
survive the IO completion.
Signed-off-by: Julian Wiedmann <jwi@xxxxxxxxxxxxx>
---
drivers/s390/net/qeth_core.h | 7 ++++
drivers/s390/net/qeth_core_main.c | 54 ++++++++++++++++++-------------
drivers/s390/net/qeth_l2_main.c | 1 -
drivers/s390/net/qeth_l3_main.c | 1 -
4 files changed, 39 insertions(+), 24 deletions(-)
diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index 962945a63235..5bcdede5e955 100644
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -579,6 +579,7 @@ struct qeth_channel;
struct qeth_cmd_buffer {
enum qeth_cmd_buffer_state state;
unsigned int length;
+ refcount_t ref_count;
struct qeth_channel *channel;
struct qeth_reply *reply;
long timeout;
@@ -588,6 +589,11 @@ struct qeth_cmd_buffer {
void (*callback)(struct qeth_card *card, struct qeth_cmd_buffer *iob);
};
+static inline void qeth_get_cmd(struct qeth_cmd_buffer *iob)
+{
+ refcount_inc(&iob->ref_count);
+}
+
static inline struct qeth_ipa_cmd *__ipa_cmd(struct qeth_cmd_buffer *iob)
{
return (struct qeth_ipa_cmd *)(iob->data + IPA_PDU_HEADER_SIZE);
@@ -771,6 +777,7 @@ struct qeth_card {
enum qeth_card_states state;
spinlock_t lock;
struct ccwgroup_device *gdev;
+ struct qeth_cmd_buffer *read_cmd;
struct qeth_channel read;
struct qeth_channel write;
struct qeth_channel data;
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 11e6a3820421..fe3dfeaf5ceb 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -496,26 +496,21 @@ static void qeth_setup_ccw(struct ccw1 *ccw, u8 cmd_code, u8 flags, u32 len,
static int __qeth_issue_next_read(struct qeth_card *card)
{
- struct qeth_channel *channel = &card->read;
- struct qeth_cmd_buffer *iob;
- struct ccw1 *ccw;
+ struct qeth_cmd_buffer *iob = card->read_cmd;
+ struct qeth_channel *channel = iob->channel;
+ struct ccw1 *ccw = __ccw_from_cmd(iob);
int rc;
QETH_CARD_TEXT(card, 5, "issnxrd");
if (channel->state != CH_STATE_UP)
return -EIO;
- iob = qeth_get_buffer(channel);
- if (!iob) {
- dev_warn(&card->gdev->dev, "The qeth device driver "
- "failed to recover an error on the device\n");
- QETH_DBF_MESSAGE(2, "issue_next_read on device %x failed: no iob available\n",
- CARD_DEVID(card));
- return -ENOMEM;
- }
- ccw = __ccw_from_cmd(iob);
- qeth_setup_ccw(ccw, CCW_CMD_READ, 0, QETH_BUFSIZE, iob->data);
+ memset(iob->data, 0, iob->length);
+ qeth_setup_ccw(ccw, CCW_CMD_READ, 0, iob->length, iob->data);
iob->callback = qeth_issue_next_read_cb;
+ /* keep the cmd alive after completion: */
+ qeth_get_cmd(iob);
+
QETH_CARD_TEXT(card, 6, "noirqpnd");
rc = ccw_device_start(channel->ccwdev, ccw, (addr_t) iob, 0, 0);
if (rc) {
@@ -694,6 +689,16 @@ static int qeth_check_idx_response(struct qeth_card *card,
return 0;
}
+static void qeth_put_cmd(struct qeth_cmd_buffer *iob)
+{
+ if (refcount_dec_and_test(&iob->ref_count)) {
+ if (iob->reply)
+ qeth_put_reply(iob->reply);
+ kfree(iob->data);
+ kfree(iob);
+ }
+}
+
static struct qeth_cmd_buffer *__qeth_get_buffer(struct qeth_channel *channel)
{
__u8 index;
@@ -720,10 +725,7 @@ void qeth_release_buffer(struct qeth_cmd_buffer *iob)
unsigned long flags;
if (iob->state == BUF_STATE_MALLOC) {
- if (iob->reply)
- qeth_put_reply(iob->reply);
- kfree(iob->data);
- kfree(iob);
+ qeth_put_cmd(iob);
return;
}
@@ -787,6 +789,7 @@ static struct qeth_cmd_buffer *qeth_alloc_cmd(struct qeth_channel *channel,
}
iob->state = BUF_STATE_MALLOC;
+ refcount_set(&iob->ref_count, 1);
iob->channel = channel;
iob->timeout = timeout;
iob->length = length;
@@ -1445,10 +1448,14 @@ static struct qeth_card *qeth_alloc_card(struct ccwgroup_device *gdev)
dev_name(&gdev->dev));
if (!card->event_wq)
goto out_wq;
- if (qeth_setup_channel(&card->read, true))
- goto out_ip;
+
+ card->read_cmd = qeth_alloc_cmd(&card->read, QETH_BUFSIZE, 1, 0);
+ if (!card->read_cmd)
+ goto out_read_cmd;
+ if (qeth_setup_channel(&card->read, false))
+ goto out_read;
if (qeth_setup_channel(&card->write, true))
- goto out_channel;
+ goto out_write;
if (qeth_setup_channel(&card->data, false))
goto out_data;
card->qeth_service_level.seq_print = qeth_core_sl_print;
@@ -1457,9 +1464,11 @@ static struct qeth_card *qeth_alloc_card(struct ccwgroup_device *gdev)
out_data:
qeth_clean_channel(&card->write);
-out_channel:
+out_write:
qeth_clean_channel(&card->read);
-out_ip:
+out_read:
+ qeth_release_buffer(card->read_cmd);
+out_read_cmd:
destroy_workqueue(card->event_wq);
out_wq:
dev_set_drvdata(&gdev->dev, NULL);
@@ -4892,6 +4901,7 @@ static void qeth_core_free_card(struct qeth_card *card)
qeth_clean_channel(&card->read);
qeth_clean_channel(&card->write);
qeth_clean_channel(&card->data);
+ qeth_release_buffer(card->read_cmd);
destroy_workqueue(card->event_wq);
qeth_free_qdio_queues(card);
unregister_service_level(&card->qeth_service_level);
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index e1b25084dcd4..9565ef9747c1 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -292,7 +292,6 @@ static void qeth_l2_stop_card(struct qeth_card *card)
card->state = CARD_STATE_DOWN;
}
- qeth_clear_cmd_buffers(&card->read);
qeth_clear_cmd_buffers(&card->write);
flush_workqueue(card->event_wq);
card->info.mac_bits &= ~QETH_LAYER2_MAC_REGISTERED;
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 15758f45837d..4d66f9556451 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -1436,7 +1436,6 @@ static void qeth_l3_stop_card(struct qeth_card *card)
card->state = CARD_STATE_DOWN;
}
- qeth_clear_cmd_buffers(&card->read);
qeth_clear_cmd_buffers(&card->write);
flush_workqueue(card->event_wq);
}
--
2.17.1
