qeth: add support for af_iucv HiperSockets transport

This patch extends the HiperSockets device driver to send and receive
af_iucv traffic over HiperSockets transport.
TX: Driver uses new asynchronous delivery of storage blocks to pass
    flow control/congestion information from the HiperSockets microcode
    to the af_iucv socket.
RX: Memory for incoming traffic is preallocated and passed to
    HiperSockets layer. If receiver is not capable to clean its buffers
    shared with HiperSockets and pass new memory to the HiperSockets
    layer this will cause flow control/congestion events on the
    sender.

Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: Einar Lueck <elelueck@de.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 190 insertions, 40 deletions

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 68a92b06526b..97172f8a15b7 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -21,6 +21,7 @@
 #include <linux/mii.h>
 #include <linux/kthread.h>
 #include <linux/slab.h>
+#include <net/iucv/af_iucv.h>
 
 #include <asm/ebcdic.h>
 #include <asm/io.h>
@@ -58,6 +59,10 @@ static void qeth_setup_ccw(struct qeth_channel *, unsigned char *, __u32);
 static void qeth_free_buffer_pool(struct qeth_card *);
 static int qeth_qdio_establish(struct qeth_card *);
 static void qeth_free_qdio_buffers(struct qeth_card *);
+static void qeth_notify_skbs(struct qeth_qdio_out_q *queue,
+		struct qeth_qdio_out_buffer *buf,
+		enum iucv_tx_notify notification);
+static void qeth_release_skbs(struct qeth_qdio_out_buffer *buf);
 static void qeth_clear_output_buffer(struct qeth_qdio_out_q *queue,
 		struct qeth_qdio_out_buffer *buf,
 		enum qeth_qdio_buffer_states newbufstate);
@@ -204,7 +209,7 @@ static int qeth_alloc_buffer_pool(struct qeth_card *card)
 
 	QETH_CARD_TEXT(card, 5, "alocpool");
 	for (i = 0; i < card->qdio.init_pool.buf_count; ++i) {
-		pool_entry = kmalloc(sizeof(*pool_entry), GFP_KERNEL);
+		pool_entry = kzalloc(sizeof(*pool_entry), GFP_KERNEL);
 		if (!pool_entry) {
 			qeth_free_buffer_pool(card);
 			return -ENOMEM;
@@ -331,6 +336,30 @@ static inline void qeth_free_cq(struct qeth_card *card)
 	card->qdio.out_bufstates = NULL;
 }
 
+static inline enum iucv_tx_notify qeth_compute_cq_notification(int sbalf15,
+	int delayed) {
+	enum iucv_tx_notify n;
+
+	switch (sbalf15) {
+	case 0:
+		n = delayed ? TX_NOTIFY_DELAYED_OK : TX_NOTIFY_OK;
+		break;
+	case 4:
+	case 16:
+	case 17:
+	case 18:
+		n = delayed ? TX_NOTIFY_DELAYED_UNREACHABLE :
+			TX_NOTIFY_UNREACHABLE;
+		break;
+	default:
+		n = delayed ? TX_NOTIFY_DELAYED_GENERALERROR :
+			TX_NOTIFY_GENERALERROR;
+		break;
+	}
+
+	return n;
+}
+
 static inline void qeth_cleanup_handled_pending(struct qeth_qdio_out_q *q,
 	int bidx, int forced_cleanup)
 {
@@ -345,6 +374,11 @@ static inline void qeth_cleanup_handled_pending(struct qeth_qdio_out_q *q,
 				struct qeth_qdio_out_buffer *f = c;
 				QETH_CARD_TEXT(f->q->card, 5, "fp");
 				QETH_CARD_TEXT_(f->q->card, 5, "%lx", (long) f);
+				/* release here to avoid interleaving between
+				   outbound tasklet and inbound tasklet
+				   regarding notifications and lifecycle */
+				qeth_release_skbs(c);
+
 				c = f->next_pending;
 				BUG_ON(head->next_pending != f);
 				head->next_pending = c;
@@ -363,6 +397,7 @@ static inline void qeth_qdio_handle_aob(struct qeth_card *card,
 		unsigned long phys_aob_addr) {
 	struct qaob *aob;
 	struct qeth_qdio_out_buffer *buffer;
+	enum iucv_tx_notify notification;
 
 	aob = (struct qaob *) phys_to_virt(phys_aob_addr);
 	QETH_CARD_TEXT(card, 5, "haob");
@@ -372,6 +407,22 @@ static inline void qeth_qdio_handle_aob(struct qeth_card *card,
 
 	BUG_ON(buffer == NULL);
 
+	if (atomic_cmpxchg(&buffer->state, QETH_QDIO_BUF_PRIMED,
+			   QETH_QDIO_BUF_IN_CQ) == QETH_QDIO_BUF_PRIMED) {
+		notification = TX_NOTIFY_OK;
+	} else {
+		BUG_ON(atomic_read(&buffer->state) != QETH_QDIO_BUF_PENDING);
+
+		atomic_set(&buffer->state, QETH_QDIO_BUF_IN_CQ);
+		notification = TX_NOTIFY_DELAYED_OK;
+	}
+
+	if (aob->aorc != 0)  {
+		QETH_CARD_TEXT_(card, 2, "aorc%02X", aob->aorc);
+		notification = qeth_compute_cq_notification(aob->aorc, 1);
+	}
+	qeth_notify_skbs(buffer->q, buffer, notification);
+
 	buffer->aob = NULL;
 	qeth_clear_output_buffer(buffer->q, buffer,
 				QETH_QDIO_BUF_HANDLED_DELAYED);
@@ -738,7 +789,7 @@ static int qeth_setup_channel(struct qeth_channel *channel)
 	QETH_DBF_TEXT(SETUP, 2, "setupch");
 	for (cnt = 0; cnt < QETH_CMD_BUFFER_NO; cnt++) {
 		channel->iob[cnt].data =
-			kmalloc(QETH_BUFSIZE, GFP_DMA|GFP_KERNEL);
+			kzalloc(QETH_BUFSIZE, GFP_DMA|GFP_KERNEL);
 		if (channel->iob[cnt].data == NULL)
 			break;
 		channel->iob[cnt].state = BUF_STATE_FREE;
@@ -1033,23 +1084,60 @@ out:
 	return;
 }
 
-static void qeth_clear_output_buffer(struct qeth_qdio_out_q *queue,
+static void qeth_notify_skbs(struct qeth_qdio_out_q *q,
 		struct qeth_qdio_out_buffer *buf,
-		enum qeth_qdio_buffer_states newbufstate)
+		enum iucv_tx_notify notification)
 {
-	int i;
 	struct sk_buff *skb;
 
-	/* is PCI flag set on buffer? */
-	if (buf->buffer->element[0].sflags & SBAL_SFLAGS0_PCI_REQ)
-		atomic_dec(&queue->set_pci_flags_count);
+	if (skb_queue_empty(&buf->skb_list))
+		goto out;
+	skb = skb_peek(&buf->skb_list);
+	while (skb) {
+		QETH_CARD_TEXT_(q->card, 5, "skbn%d", notification);
+		QETH_CARD_TEXT_(q->card, 5, "%lx", (long) skb);
+		if (skb->protocol == ETH_P_AF_IUCV) {
+			if (skb->sk) {
+				struct iucv_sock *iucv = iucv_sk(skb->sk);
+				iucv->sk_txnotify(skb, notification);
+			}
+		}
+		if (skb_queue_is_last(&buf->skb_list, skb))
+			skb = NULL;
+		else
+			skb = skb_queue_next(&buf->skb_list, skb);
+	}
+out:
+	return;
+}
+
+static void qeth_release_skbs(struct qeth_qdio_out_buffer *buf)
+{
+	struct sk_buff *skb;
 
 	skb = skb_dequeue(&buf->skb_list);
 	while (skb) {
+		QETH_CARD_TEXT(buf->q->card, 5, "skbr");
+		QETH_CARD_TEXT_(buf->q->card, 5, "%lx", (long) skb);
 		atomic_dec(&skb->users);
 		dev_kfree_skb_any(skb);
 		skb = skb_dequeue(&buf->skb_list);
 	}
+}
+
+static void qeth_clear_output_buffer(struct qeth_qdio_out_q *queue,
+		struct qeth_qdio_out_buffer *buf,
+		enum qeth_qdio_buffer_states newbufstate)
+{
+	int i;
+
+	/* is PCI flag set on buffer? */
+	if (buf->buffer->element[0].sflags & SBAL_SFLAGS0_PCI_REQ)
+		atomic_dec(&queue->set_pci_flags_count);
+
+	if (newbufstate == QETH_QDIO_BUF_EMPTY) {
+		qeth_release_skbs(buf);
+	}
 	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,
@@ -1111,14 +1199,16 @@ static void qeth_free_buffer_pool(struct qeth_card *card)
 
 static void qeth_free_qdio_buffers(struct qeth_card *card)
 {
-	int i;
+	int i, j;
 
 	if (atomic_xchg(&card->qdio.state, QETH_QDIO_UNINITIALIZED) ==
 		QETH_QDIO_UNINITIALIZED)
 		return;
 
 	qeth_free_cq(card);
-
+	cancel_delayed_work_sync(&card->buffer_reclaim_work);
+	for (j = 0; j < QDIO_MAX_BUFFERS_PER_Q; ++j)
+		kfree_skb(card->qdio.in_q->bufs[j].rx_skb);
 	kfree(card->qdio.in_q);
 	card->qdio.in_q = NULL;
 	/* inbound buffer pool */
@@ -1289,6 +1379,7 @@ static int qeth_setup_card(struct qeth_card *card)
 	card->ipato.invert6 = 0;
 	/* init QDIO stuff */
 	qeth_init_qdio_info(card);
+	INIT_DELAYED_WORK(&card->buffer_reclaim_work, qeth_buffer_reclaim_work);
 	return 0;
 }
 
@@ -1310,7 +1401,7 @@ static struct qeth_card *qeth_alloc_card(void)
 	if (!card)
 		goto out;
 	QETH_DBF_HEX(SETUP, 2, &card, sizeof(void *));
-	card->ip_tbd_list = kmalloc(sizeof(struct list_head), GFP_KERNEL);
+	card->ip_tbd_list = kzalloc(sizeof(struct list_head), GFP_KERNEL);
 	if (!card->ip_tbd_list) {
 		QETH_DBF_TEXT(SETUP, 0, "iptbdnom");
 		goto out_card;
@@ -2239,7 +2330,7 @@ static int qeth_alloc_qdio_buffers(struct qeth_card *card)
 		QETH_QDIO_ALLOCATED) != QETH_QDIO_UNINITIALIZED)
 		return 0;
 
-	card->qdio.in_q = kmalloc(sizeof(struct qeth_qdio_q),
+	card->qdio.in_q = kzalloc(sizeof(struct qeth_qdio_q),
 				   GFP_KERNEL);
 	if (!card->qdio.in_q)
 		goto out_nomem;
@@ -2247,27 +2338,28 @@ static int qeth_alloc_qdio_buffers(struct qeth_card *card)
 	QETH_DBF_HEX(SETUP, 2, &card->qdio.in_q, sizeof(void *));
 	memset(card->qdio.in_q, 0, sizeof(struct qeth_qdio_q));
 	/* give inbound qeth_qdio_buffers their qdio_buffers */
-	for (i = 0; i < QDIO_MAX_BUFFERS_PER_Q; ++i)
+	for (i = 0; i < QDIO_MAX_BUFFERS_PER_Q; ++i) {
 		card->qdio.in_q->bufs[i].buffer =
 			&card->qdio.in_q->qdio_bufs[i];
+		card->qdio.in_q->bufs[i].rx_skb = NULL;
+	}
 	/* inbound buffer pool */
 	if (qeth_alloc_buffer_pool(card))
 		goto out_freeinq;
 
 	/* outbound */
 	card->qdio.out_qs =
-		kmalloc(card->qdio.no_out_queues *
+		kzalloc(card->qdio.no_out_queues *
 			sizeof(struct qeth_qdio_out_q *), GFP_KERNEL);
 	if (!card->qdio.out_qs)
 		goto out_freepool;
 	for (i = 0; i < card->qdio.no_out_queues; ++i) {
-		card->qdio.out_qs[i] = kmalloc(sizeof(struct qeth_qdio_out_q),
+		card->qdio.out_qs[i] = kzalloc(sizeof(struct qeth_qdio_out_q),
 					       GFP_KERNEL);
 		if (!card->qdio.out_qs[i])
 			goto out_freeoutq;
 		QETH_DBF_TEXT_(SETUP, 2, "outq %i", i);
 		QETH_DBF_HEX(SETUP, 2, &card->qdio.out_qs[i], sizeof(void *));
-		memset(card->qdio.out_qs[i], 0, sizeof(struct qeth_qdio_out_q));
 		card->qdio.out_qs[i]->queue_no = i;
 		/* give outbound qeth_qdio_buffers their qdio_buffers */
 		for (j = 0; j < QDIO_MAX_BUFFERS_PER_Q; ++j) {
@@ -2565,6 +2657,12 @@ static int qeth_init_input_buffer(struct qeth_card *card,
 	struct qeth_buffer_pool_entry *pool_entry;
 	int i;
 
+	if ((card->options.cq == QETH_CQ_ENABLED) && (!buf->rx_skb)) {
+		buf->rx_skb = dev_alloc_skb(QETH_RX_PULL_LEN + ETH_HLEN);
+		if (!buf->rx_skb)
+			return 1;
+	}
+
 	pool_entry = qeth_find_free_buffer_pool_entry(card);
 	if (!pool_entry)
 		return 1;
@@ -2954,9 +3052,19 @@ int qeth_check_qdio_errors(struct qeth_card *card, struct qdio_buffer *buf,
 }
 EXPORT_SYMBOL_GPL(qeth_check_qdio_errors);
 
+void qeth_buffer_reclaim_work(struct work_struct *work)
+{
+	struct qeth_card *card = container_of(work, struct qeth_card,
+		buffer_reclaim_work.work);
+
+	QETH_CARD_TEXT_(card, 2, "brw:%x", card->reclaim_index);
+	qeth_queue_input_buffer(card, card->reclaim_index);
+}
+
 void qeth_queue_input_buffer(struct qeth_card *card, int index)
 {
 	struct qeth_qdio_q *queue = card->qdio.in_q;
+	struct list_head *lh;
 	int count;
 	int i;
 	int rc;
@@ -2988,6 +3096,20 @@ void qeth_queue_input_buffer(struct qeth_card *card, int index)
 			atomic_add_unless(&card->force_alloc_skb, -1, 0);
 		}
 
+		if (!count) {
+			i = 0;
+			list_for_each(lh, &card->qdio.in_buf_pool.entry_list)
+				i++;
+			if (i == card->qdio.in_buf_pool.buf_count) {
+				QETH_CARD_TEXT(card, 2, "qsarbw");
+				card->reclaim_index = index;
+				schedule_delayed_work(
+					&card->buffer_reclaim_work,
+					QETH_RECLAIM_WORK_TIME);
+			}
+			return;
+		}
+
 		/*
 		 * according to old code it should be avoided to requeue all
 		 * 128 buffers in order to benefit from PCI avoidance.
@@ -3396,15 +3518,34 @@ void qeth_qdio_output_handler(struct ccw_device *ccwdev,
 		if (queue->bufstates &&
 		    (queue->bufstates[bidx].flags &
 		     QDIO_OUTBUF_STATE_FLAG_PENDING) != 0) {
+			BUG_ON(card->options.cq != QETH_CQ_ENABLED);
+
+			if (atomic_cmpxchg(&buffer->state,
+					   QETH_QDIO_BUF_PRIMED,
+					   QETH_QDIO_BUF_PENDING) ==
+				QETH_QDIO_BUF_PRIMED) {
+				qeth_notify_skbs(queue, buffer,
+						 TX_NOTIFY_PENDING);
+			}
 			buffer->aob = queue->bufstates[bidx].aob;
 			QETH_CARD_TEXT_(queue->card, 5, "pel%d", bidx);
-			QETH_CARD_TEXT_(queue->card, 5, "aob");
+			QETH_CARD_TEXT(queue->card, 5, "aob");
 			QETH_CARD_TEXT_(queue->card, 5, "%lx",
 					virt_to_phys(buffer->aob));
 			BUG_ON(bidx < 0 || bidx >= QDIO_MAX_BUFFERS_PER_Q);
-			if (qeth_init_qdio_out_buf(queue, bidx))
+			if (qeth_init_qdio_out_buf(queue, bidx)) {
+				QETH_CARD_TEXT(card, 2, "outofbuf");
 				qeth_schedule_recovery(card);
+			}
 		} else {
+			if (card->options.cq == QETH_CQ_ENABLED) {
+				enum iucv_tx_notify n;
+
+				n = qeth_compute_cq_notification(
+					buffer->buffer->element[15].sflags, 0);
+				qeth_notify_skbs(queue, buffer, n);
+			}
+
 			qeth_clear_output_buffer(queue, buffer,
 						QETH_QDIO_BUF_EMPTY);
 		}
@@ -4335,7 +4476,7 @@ static int qeth_qdio_establish(struct qeth_card *card)
 	qeth_create_qib_param_field(card, qib_param_field);
 	qeth_create_qib_param_field_blkt(card, qib_param_field);
 
-	in_sbal_ptrs = kmalloc(card->qdio.no_in_queues *
+	in_sbal_ptrs = kzalloc(card->qdio.no_in_queues *
 			       QDIO_MAX_BUFFERS_PER_Q * sizeof(void *),
 			       GFP_KERNEL);
 	if (!in_sbal_ptrs) {
@@ -4359,7 +4500,7 @@ static int qeth_qdio_establish(struct qeth_card *card)
 	qeth_qdio_establish_cq(card, in_sbal_ptrs, queue_start_poll);
 
 	out_sbal_ptrs =
-		kmalloc(card->qdio.no_out_queues * QDIO_MAX_BUFFERS_PER_Q *
+		kzalloc(card->qdio.no_out_queues * QDIO_MAX_BUFFERS_PER_Q *
 			sizeof(void *), GFP_KERNEL);
 	if (!out_sbal_ptrs) {
 		rc = -ENOMEM;
@@ -4557,29 +4698,36 @@ out:
 }
 EXPORT_SYMBOL_GPL(qeth_core_hardsetup_card);
 
-static inline int qeth_create_skb_frag(struct qdio_buffer_element *element,
+static inline int qeth_create_skb_frag(struct qeth_qdio_buffer *qethbuffer,
+		struct qdio_buffer_element *element,
 		struct sk_buff **pskb, int offset, int *pfrag, int data_len)
 {
 	struct page *page = virt_to_page(element->addr);
 	if (*pskb == NULL) {
-		/* the upper protocol layers assume that there is data in the
-		 * skb itself. Copy a small amount (64 bytes) to make them
-		 * happy. */
-		*pskb = dev_alloc_skb(64 + ETH_HLEN);
-		if (!(*pskb))
-			return -ENOMEM;
+		if (qethbuffer->rx_skb) {
+			/* only if qeth_card.options.cq == QETH_CQ_ENABLED */
+			*pskb = qethbuffer->rx_skb;
+			qethbuffer->rx_skb = NULL;
+		} else {
+			*pskb = dev_alloc_skb(QETH_RX_PULL_LEN + ETH_HLEN);
+			if (!(*pskb))
+				return -ENOMEM;
+		}
+
 		skb_reserve(*pskb, ETH_HLEN);
-		if (data_len <= 64) {
+		if (data_len <= QETH_RX_PULL_LEN) {
 			memcpy(skb_put(*pskb, data_len), element->addr + offset,
 				data_len);
 		} else {
 			get_page(page);
-			memcpy(skb_put(*pskb, 64), element->addr + offset, 64);
-			skb_fill_page_desc(*pskb, *pfrag, page, offset + 64,
-				data_len - 64);
-			(*pskb)->data_len += data_len - 64;
-			(*pskb)->len      += data_len - 64;
-			(*pskb)->truesize += data_len - 64;
+			memcpy(skb_put(*pskb, QETH_RX_PULL_LEN),
+			       element->addr + offset, QETH_RX_PULL_LEN);
+			skb_fill_page_desc(*pskb, *pfrag, page,
+				offset + QETH_RX_PULL_LEN,
+				data_len - QETH_RX_PULL_LEN);
+			(*pskb)->data_len += data_len - QETH_RX_PULL_LEN;
+			(*pskb)->len      += data_len - QETH_RX_PULL_LEN;
+			(*pskb)->truesize += data_len - QETH_RX_PULL_LEN;
 			(*pfrag)++;
 		}
 	} else {
@@ -4596,11 +4744,12 @@ static inline int qeth_create_skb_frag(struct qdio_buffer_element *element,
 }
 
 struct sk_buff *qeth_core_get_next_skb(struct qeth_card *card,
-		struct qdio_buffer *buffer,
+		struct qeth_qdio_buffer *qethbuffer,
 		struct qdio_buffer_element **__element, int *__offset,
 		struct qeth_hdr **hdr)
 {
 	struct qdio_buffer_element *element = *__element;
+	struct qdio_buffer *buffer = qethbuffer->buffer;
 	int offset = *__offset;
 	struct sk_buff *skb = NULL;
 	int skb_len = 0;
@@ -4645,9 +4794,10 @@ struct sk_buff *qeth_core_get_next_skb(struct qeth_card *card,
 	if (!skb_len)
 		return NULL;
 
-	if ((skb_len >= card->options.rx_sg_cb) &&
-	    (!(card->info.type == QETH_CARD_TYPE_OSN)) &&
-	    (!atomic_read(&card->force_alloc_skb))) {
+	if (((skb_len >= card->options.rx_sg_cb) &&
+	     (!(card->info.type == QETH_CARD_TYPE_OSN)) &&
+	     (!atomic_read(&card->force_alloc_skb))) ||
+	    (card->options.cq == QETH_CQ_ENABLED)) {
 		use_rx_sg = 1;
 	} else {
 		skb = dev_alloc_skb(skb_len + headroom);
@@ -4662,8 +4812,8 @@ struct sk_buff *qeth_core_get_next_skb(struct qeth_card *card,
 		data_len = min(skb_len, (int)(element->length - offset));
 		if (data_len) {
 			if (use_rx_sg) {
-				if (qeth_create_skb_frag(element, &skb, offset,
-				    &frag, data_len))
+				if (qeth_create_skb_frag(qethbuffer, element,
+				    &skb, offset, &frag, data_len))
 					goto no_mem;
 			} else {
 				memcpy(skb_put(skb, data_len), data_ptr,