s390/qdio: allow for non-contiguous SBAL array in init_data

Upper-layer drivers allocate their SBALs by calling qdio_alloc_buffers()
for each individual queue. But when later passing the SBAL addresses to
qdio_establish(), they need to be in a single array of pointers.
So if the driver uses multiple Input or Output queues, it needs to
allocate a temporary array just to present all its SBAL pointers in this
layout.

This patch slightly changes the format of the QDIO initialization data,
so that drivers can pass a per-queue array where each element points to
a queue's SBAL array.
zfcp doesn't use multiple queues, so the impact there is trivial.
For qeth this brings a nice reduction in complexity, and removes
a page-sized allocation.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

2 files changed, 13 insertions, 51 deletions

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index acda230323d5..e0b26310ecab 100644
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -181,11 +181,12 @@ struct qeth_vnicc_info {
 /*****************************************************************************/
 /* QDIO queue and buffer handling                                            */
 /*****************************************************************************/
-#define QETH_MAX_QUEUES 4
+#define QETH_MAX_OUT_QUEUES	4
 #define QETH_IQD_MIN_TXQ	2	/* One for ucast, one for mcast. */
 #define QETH_IQD_MCAST_TXQ	0
 #define QETH_IQD_MIN_UCAST_TXQ	1
 
+#define QETH_MAX_IN_QUEUES	2
 #define QETH_RX_COPYBREAK      (PAGE_SIZE >> 1)
 #define QETH_IN_BUF_SIZE_DEFAULT 65536
 #define QETH_IN_BUF_COUNT_DEFAULT 64
@@ -539,7 +540,7 @@ struct qeth_qdio_info {
 
 	/* output */
 	int no_out_queues;
-	struct qeth_qdio_out_q *out_qs[QETH_MAX_QUEUES];
+	struct qeth_qdio_out_q *out_qs[QETH_MAX_OUT_QUEUES];
 	struct qdio_outbuf_state *out_bufstates;
 
 	/* priority queueing */
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 19b2773fc2d3..4f90f11942b1 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -4812,28 +4812,13 @@ out:
 	return;
 }
 
-static void qeth_qdio_establish_cq(struct qeth_card *card,
-				   struct qdio_buffer **in_sbal_ptrs)
-{
-	int i;
-
-	if (card->options.cq == QETH_CQ_ENABLED) {
-		int offset = QDIO_MAX_BUFFERS_PER_Q *
-			     (card->qdio.no_in_queues - 1);
-
-		for (i = 0; i < QDIO_MAX_BUFFERS_PER_Q; i++)
-			in_sbal_ptrs[offset + i] =
-				card->qdio.c_q->bufs[i].buffer;
-	}
-}
-
 static int qeth_qdio_establish(struct qeth_card *card)
 {
+	struct qdio_buffer **out_sbal_ptrs[QETH_MAX_OUT_QUEUES];
+	struct qdio_buffer **in_sbal_ptrs[QETH_MAX_IN_QUEUES];
 	struct qdio_initialize init_data;
 	char *qib_param_field;
-	struct qdio_buffer **in_sbal_ptrs;
-	struct qdio_buffer **out_sbal_ptrs;
-	int i, j, k;
+	unsigned int i;
 	int rc = 0;
 
 	QETH_CARD_TEXT(card, 2, "qdioest");
@@ -4847,32 +4832,12 @@ 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 = kcalloc(card->qdio.no_in_queues * QDIO_MAX_BUFFERS_PER_Q,
-			       sizeof(void *),
-			       GFP_KERNEL);
-	if (!in_sbal_ptrs) {
-		rc = -ENOMEM;
-		goto out_free_qib_param;
-	}
-
-	for (i = 0; i < QDIO_MAX_BUFFERS_PER_Q; i++)
-		in_sbal_ptrs[i] = card->qdio.in_q->bufs[i].buffer;
-
-	qeth_qdio_establish_cq(card, in_sbal_ptrs);
-
-	out_sbal_ptrs =
-		kcalloc(card->qdio.no_out_queues * QDIO_MAX_BUFFERS_PER_Q,
-			sizeof(void *),
-			GFP_KERNEL);
-	if (!out_sbal_ptrs) {
-		rc = -ENOMEM;
-		goto out_free_in_sbals;
-	}
+	in_sbal_ptrs[0] = card->qdio.in_q->qdio_bufs;
+	if (card->options.cq == QETH_CQ_ENABLED)
+		in_sbal_ptrs[1] = card->qdio.c_q->qdio_bufs;
 
-	for (i = 0, k = 0; i < card->qdio.no_out_queues; ++i)
-		for (j = 0; j < QDIO_MAX_BUFFERS_PER_Q; j++, k++)
-			out_sbal_ptrs[k] =
-				card->qdio.out_qs[i]->bufs[j]->buffer;
+	for (i = 0; i < card->qdio.no_out_queues; i++)
+		out_sbal_ptrs[i] = card->qdio.out_qs[i]->qdio_bufs;
 
 	memset(&init_data, 0, sizeof(struct qdio_initialize));
 	init_data.cdev                   = CARD_DDEV(card);
@@ -4917,10 +4882,6 @@ static int qeth_qdio_establish(struct qeth_card *card)
 		break;
 	}
 out:
-	kfree(out_sbal_ptrs);
-out_free_in_sbals:
-	kfree(in_sbal_ptrs);
-out_free_qib_param:
 	kfree(qib_param_field);
 out_free_nothing:
 	return rc;
@@ -5986,7 +5947,7 @@ static struct net_device *qeth_alloc_netdev(struct qeth_card *card)
 	switch (card->info.type) {
 	case QETH_CARD_TYPE_IQD:
 		dev = alloc_netdev_mqs(sizeof(*priv), "hsi%d", NET_NAME_UNKNOWN,
-				       ether_setup, QETH_MAX_QUEUES, 1);
+				       ether_setup, QETH_MAX_OUT_QUEUES, 1);
 		break;
 	case QETH_CARD_TYPE_OSM:
 		dev = alloc_etherdev(sizeof(*priv));
@@ -5996,7 +5957,7 @@ static struct net_device *qeth_alloc_netdev(struct qeth_card *card)
 				   ether_setup);
 		break;
 	default:
-		dev = alloc_etherdev_mqs(sizeof(*priv), QETH_MAX_QUEUES, 1);
+		dev = alloc_etherdev_mqs(sizeof(*priv), QETH_MAX_OUT_QUEUES, 1);
 	}
 
 	if (!dev)