[S390] qeth: preallocated qeth header for hiper socket

For hiper socket devices this patch will economize the reallocation
of the tx skb data segment by allocating separate memory for the qdio
transport information (qeth header).

Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 46 insertions, 13 deletions

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index cebb25e36e82..7a5549919717 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -48,6 +48,8 @@ EXPORT_SYMBOL_GPL(qeth_dbf);
 
 struct qeth_card_list_struct qeth_core_card_list;
 EXPORT_SYMBOL_GPL(qeth_core_card_list);
+struct kmem_cache *qeth_core_header_cache;
+EXPORT_SYMBOL_GPL(qeth_core_header_cache);
 
 static struct device *qeth_core_root_dev;
 static unsigned int known_devices[][10] = QETH_MODELLIST_ARRAY;
@@ -933,6 +935,10 @@ static void qeth_clear_output_buffer(struct qeth_qdio_out_q *queue,
 	}
 	qeth_eddp_buf_release_contexts(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,
+				buf->buffer->element[i].addr);
+		buf->is_header[i] = 0;
 		buf->buffer->element[i].length = 0;
 		buf->buffer->element[i].addr = NULL;
 		buf->buffer->element[i].flags = 0;
@@ -3002,8 +3008,8 @@ int qeth_get_elements_no(struct qeth_card *card, void *hdr,
 	if (skb_shinfo(skb)->nr_frags > 0)
 		elements_needed = (skb_shinfo(skb)->nr_frags + 1);
 	if (elements_needed == 0)
-		elements_needed = 1 + (((((unsigned long) hdr) % PAGE_SIZE)
-			+ skb->len) >> PAGE_SHIFT);
+		elements_needed = 1 + (((((unsigned long) skb->data) %
+				PAGE_SIZE) + skb->len) >> PAGE_SHIFT);
 	if ((elements_needed + elems) > QETH_MAX_BUFFER_ELEMENTS(card)) {
 		QETH_DBF_MESSAGE(2, "Invalid size of IP packet "
 			"(Number=%d / Length=%d). Discarded.\n",
@@ -3015,7 +3021,8 @@ int qeth_get_elements_no(struct qeth_card *card, void *hdr,
 EXPORT_SYMBOL_GPL(qeth_get_elements_no);
 
 static inline void __qeth_fill_buffer(struct sk_buff *skb,
-	struct qdio_buffer *buffer, int is_tso, int *next_element_to_fill)
+	struct qdio_buffer *buffer, int is_tso, int *next_element_to_fill,
+	int offset)
 {
 	int length = skb->len;
 	int length_here;
@@ -3027,6 +3034,11 @@ static inline void __qeth_fill_buffer(struct sk_buff *skb,
 	data = skb->data;
 	first_lap = (is_tso == 0 ? 1 : 0);
 
+	if (offset >= 0) {
+		data = skb->data + offset;
+		first_lap = 0;
+	}
+
 	while (length > 0) {
 		/* length_here is the remaining amount of data in this page */
 		length_here = PAGE_SIZE - ((unsigned long) data % PAGE_SIZE);
@@ -3058,22 +3070,22 @@ static inline void __qeth_fill_buffer(struct sk_buff *skb,
 }
 
 static inline int qeth_fill_buffer(struct qeth_qdio_out_q *queue,
-		struct qeth_qdio_out_buffer *buf, struct sk_buff *skb)
+		struct qeth_qdio_out_buffer *buf, struct sk_buff *skb,
+		struct qeth_hdr *hdr, int offset, int hd_len)
 {
 	struct qdio_buffer *buffer;
-	struct qeth_hdr_tso *hdr;
 	int flush_cnt = 0, hdr_len, large_send = 0;
 
 	buffer = buf->buffer;
 	atomic_inc(&skb->users);
 	skb_queue_tail(&buf->skb_list, skb);
 
-	hdr  = (struct qeth_hdr_tso *) skb->data;
 	/*check first on TSO ....*/
-	if (hdr->hdr.hdr.l3.id == QETH_HEADER_TYPE_TSO) {
+	if (hdr->hdr.l3.id == QETH_HEADER_TYPE_TSO) {
 		int element = buf->next_element_to_fill;
 
-		hdr_len = sizeof(struct qeth_hdr_tso) + hdr->ext.dg_hdr_len;
+		hdr_len = sizeof(struct qeth_hdr_tso) +
+			((struct qeth_hdr_tso *)hdr)->ext.dg_hdr_len;
 		/*fill first buffer entry only with header information */
 		buffer->element[element].addr = skb->data;
 		buffer->element[element].length = hdr_len;
@@ -3083,9 +3095,20 @@ static inline int qeth_fill_buffer(struct qeth_qdio_out_q *queue,
 		skb->len  -= hdr_len;
 		large_send = 1;
 	}
+
+	if (offset >= 0) {
+		int element = buf->next_element_to_fill;
+		buffer->element[element].addr = hdr;
+		buffer->element[element].length = sizeof(struct qeth_hdr) +
+							hd_len;
+		buffer->element[element].flags = SBAL_FLAGS_FIRST_FRAG;
+		buf->is_header[element] = 1;
+		buf->next_element_to_fill++;
+	}
+
 	if (skb_shinfo(skb)->nr_frags == 0)
 		__qeth_fill_buffer(skb, buffer, large_send,
-				   (int *)&buf->next_element_to_fill);
+				(int *)&buf->next_element_to_fill, offset);
 	else
 		__qeth_fill_buffer_frag(skb, buffer, large_send,
 					(int *)&buf->next_element_to_fill);
@@ -3115,7 +3138,7 @@ static inline int qeth_fill_buffer(struct qeth_qdio_out_q *queue,
 int qeth_do_send_packet_fast(struct qeth_card *card,
 		struct qeth_qdio_out_q *queue, struct sk_buff *skb,
 		struct qeth_hdr *hdr, int elements_needed,
-		struct qeth_eddp_context *ctx)
+		struct qeth_eddp_context *ctx, int offset, int hd_len)
 {
 	struct qeth_qdio_out_buffer *buffer;
 	int buffers_needed = 0;
@@ -3148,7 +3171,7 @@ int qeth_do_send_packet_fast(struct qeth_card *card,
 	}
 	atomic_set(&queue->state, QETH_OUT_Q_UNLOCKED);
 	if (ctx == NULL) {
-		qeth_fill_buffer(queue, buffer, skb);
+		qeth_fill_buffer(queue, buffer, skb, hdr, offset, hd_len);
 		qeth_flush_buffers(queue, index, 1);
 	} else {
 		flush_cnt = qeth_eddp_fill_buffer(queue, ctx, index);
@@ -3224,7 +3247,7 @@ int qeth_do_send_packet(struct qeth_card *card, struct qeth_qdio_out_q *queue,
 		}
 	}
 	if (ctx == NULL)
-		tmp = qeth_fill_buffer(queue, buffer, skb);
+		tmp = qeth_fill_buffer(queue, buffer, skb, hdr, -1, 0);
 	else {
 		tmp = qeth_eddp_fill_buffer(queue, ctx,
 						queue->next_buf_to_fill);
@@ -4443,8 +4466,17 @@ static int __init qeth_core_init(void)
 	rc = IS_ERR(qeth_core_root_dev) ? PTR_ERR(qeth_core_root_dev) : 0;
 	if (rc)
 		goto register_err;
-	return 0;
 
+	qeth_core_header_cache = kmem_cache_create("qeth_hdr",
+			sizeof(struct qeth_hdr) + ETH_HLEN, 64, 0, NULL);
+	if (!qeth_core_header_cache) {
+		rc = -ENOMEM;
+		goto slab_err;
+	}
+
+	return 0;
+slab_err:
+	s390_root_dev_unregister(qeth_core_root_dev);
 register_err:
 	driver_remove_file(&qeth_core_ccwgroup_driver.driver,
 			   &driver_attr_group);
@@ -4466,6 +4498,7 @@ static void __exit qeth_core_exit(void)
 			   &driver_attr_group);
 	ccwgroup_driver_unregister(&qeth_core_ccwgroup_driver);
 	ccw_driver_unregister(&qeth_ccw_driver);
+	kmem_cache_destroy(qeth_core_header_cache);
 	qeth_unregister_dbf_views();
 	PRINT_INFO("core functions removed\n");
 }