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Commit d9b9f40b authored by Julian Wiedmann's avatar Julian Wiedmann Committed by David S. Miller
Browse files

s390/qeth: allocate a single cmd on read channel 



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: default avatarJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f3b783b1

drivers/s390/net/qeth_core.h

+7 −0
Original line number Diff line number Diff line
@@ -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;

drivers/s390/net/qeth_core_main.c

+32 −22
Original line number Diff line number Diff line
@@ -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);

drivers/s390/net/qeth_l2_main.c

+0 −1
Original line number Diff line number Diff line
@@ -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;

drivers/s390/net/qeth_l3_main.c

+0 −1
Original line number Diff line number Diff line
@@ -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);

}