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Commit 58490f18 authored by Klaus-Dieter Wacker's avatar Klaus-Dieter Wacker Committed by David S. Miller
Browse files

qeth: HiperSockets SIGA retry support on CC=2. 



Qeth HiperSockets support now retries sending of packets when the
IBM System z signals a temporary resource shortage (e.g. target
buffer full). The packet is enqueued into the device queue.
After 3 times of unsuccessful send the packet is dropped.

Signed-off-by: default avatarKlaus-Dieter Wacker <kdwacker@de.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 31ffe249

drivers/s390/net/qeth_core.h

+9 −0
Original line number Diff line number Diff line
@@ -435,6 +435,7 @@ struct qeth_qdio_out_q { 
	 * index of buffer to be filled by driver; state EMPTY or PACKING

	 */

	int next_buf_to_fill;

	int sync_iqdio_error;

	/*

	 * number of buffers that are currently filled (PRIMED)

	 * -> these buffers are hardware-owned
@@ -685,6 +686,14 @@ struct qeth_mc_mac { 
	int is_vmac;

};



struct qeth_skb_data {

	__u32 magic;

	int count;

};



#define QETH_SKB_MAGIC 0x71657468

#define QETH_SIGA_CC2_RETRIES 3



struct qeth_card {

	struct list_head list;

	enum qeth_card_states state;

drivers/s390/net/qeth_core_main.c

+52 −8
Original line number Diff line number Diff line
@@ -927,8 +927,8 @@ out: 
	return;

}



static void qeth_clear_output_buffer(struct qeth_qdio_out_q *queue,

		 struct qeth_qdio_out_buffer *buf)

static void __qeth_clear_output_buffer(struct qeth_qdio_out_q *queue,

		 struct qeth_qdio_out_buffer *buf, unsigned int qeth_skip_skb)

{

	int i;

	struct sk_buff *skb;
@@ -937,12 +937,14 @@ static void qeth_clear_output_buffer(struct qeth_qdio_out_q *queue, 
	if (buf->buffer->element[0].flags & 0x40)

		atomic_dec(&queue->set_pci_flags_count);



	if (!qeth_skip_skb) {

		skb = skb_dequeue(&buf->skb_list);

		while (skb) {

			atomic_dec(&skb->users);

			dev_kfree_skb_any(skb);

			skb = skb_dequeue(&buf->skb_list);

		}

	}

	for (i = 0; i < QETH_MAX_BUFFER_ELEMENTS(queue->card); ++i) {

		if (buf->buffer->element[i].addr && buf->is_header[i])

			kmem_cache_free(qeth_core_header_cache,
@@ -957,6 +959,12 @@ static void qeth_clear_output_buffer(struct qeth_qdio_out_q *queue, 
	atomic_set(&buf->state, QETH_QDIO_BUF_EMPTY);

}



static void qeth_clear_output_buffer(struct qeth_qdio_out_q *queue,

		struct qeth_qdio_out_buffer *buf)

{

	__qeth_clear_output_buffer(queue, buf, 0);

}



void qeth_clear_qdio_buffers(struct qeth_card *card)

{

	int i, j;
@@ -2685,6 +2693,13 @@ static int qeth_handle_send_error(struct qeth_card *card, 
	int sbalf15 = buffer->buffer->element[15].flags & 0xff;



	QETH_DBF_TEXT(TRACE, 6, "hdsnderr");

	if (card->info.type == QETH_CARD_TYPE_IQD) {

		if (sbalf15 == 0) {

			qdio_err = 0;

		} else {

			qdio_err = 1;

		}

	}

	qeth_check_qdio_errors(buffer->buffer, qdio_err, "qouterr");



	if (!qdio_err)
@@ -2817,6 +2832,7 @@ static void qeth_flush_buffers(struct qeth_qdio_out_q *queue, int index, 
		}

	}



	queue->sync_iqdio_error = 0;

	queue->card->dev->trans_start = jiffies;

	if (queue->card->options.performance_stats) {

		queue->card->perf_stats.outbound_do_qdio_cnt++;
@@ -2832,6 +2848,10 @@ static void qeth_flush_buffers(struct qeth_qdio_out_q *queue, int index, 
		queue->card->perf_stats.outbound_do_qdio_time +=

			qeth_get_micros() -

			queue->card->perf_stats.outbound_do_qdio_start_time;

	if (rc > 0) {

		if (!(rc & QDIO_ERROR_SIGA_BUSY))

			queue->sync_iqdio_error = rc & 3;

	}

	if (rc) {

		queue->card->stats.tx_errors += count;

		/* ignore temporary SIGA errors without busy condition */
@@ -2899,6 +2919,7 @@ void qeth_qdio_output_handler(struct ccw_device *ccwdev, 
	struct qeth_qdio_out_q *queue = card->qdio.out_qs[__queue];

	struct qeth_qdio_out_buffer *buffer;

	int i;

	unsigned qeth_send_err;



	QETH_DBF_TEXT(TRACE, 6, "qdouhdl");

	if (qdio_error & QDIO_ERROR_ACTIVATE_CHECK_CONDITION) {
@@ -2915,8 +2936,9 @@ void qeth_qdio_output_handler(struct ccw_device *ccwdev, 
	}

	for (i = first_element; i < (first_element + count); ++i) {

		buffer = &queue->bufs[i % QDIO_MAX_BUFFERS_PER_Q];

		qeth_handle_send_error(card, buffer, qdio_error);

		qeth_clear_output_buffer(queue, buffer);

		qeth_send_err = qeth_handle_send_error(card, buffer, qdio_error);

		__qeth_clear_output_buffer(queue, buffer,

			(qeth_send_err == QETH_SEND_ERROR_RETRY) ? 1 : 0);

	}

	atomic_sub(count, &queue->used_buffers);

	/* check if we need to do something on this outbound queue */
@@ -3159,7 +3181,10 @@ int qeth_do_send_packet_fast(struct qeth_card *card, 
		int offset, int hd_len)

{

	struct qeth_qdio_out_buffer *buffer;

	struct sk_buff *skb1;

	struct qeth_skb_data *retry_ctrl;

	int index;

	int rc;



	/* spin until we get the queue ... */

	while (atomic_cmpxchg(&queue->state, QETH_OUT_Q_UNLOCKED,
@@ -3178,6 +3203,25 @@ int qeth_do_send_packet_fast(struct qeth_card *card, 
	atomic_set(&queue->state, QETH_OUT_Q_UNLOCKED);

	qeth_fill_buffer(queue, buffer, skb, hdr, offset, hd_len);

	qeth_flush_buffers(queue, index, 1);

	if (queue->sync_iqdio_error == 2) {

		skb1 = skb_dequeue(&buffer->skb_list);

		while (skb1) {

			atomic_dec(&skb1->users);

			skb1 = skb_dequeue(&buffer->skb_list);

		}

		retry_ctrl = (struct qeth_skb_data *) &skb->cb[16];

		if (retry_ctrl->magic != QETH_SKB_MAGIC) {

			retry_ctrl->magic = QETH_SKB_MAGIC;

			retry_ctrl->count = 0;

		}

		if (retry_ctrl->count < QETH_SIGA_CC2_RETRIES) {

			retry_ctrl->count++;

			rc = dev_queue_xmit(skb);

		} else {

			dev_kfree_skb_any(skb);

			QETH_DBF_TEXT(QERR, 2, "qrdrop");

		}

	}

	return 0;

out:

	atomic_set(&queue->state, QETH_OUT_Q_UNLOCKED);