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path: root/drivers/s390/net/qeth_tso.c
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Diffstat (limited to 'drivers/s390/net/qeth_tso.c')
-rw-r--r--drivers/s390/net/qeth_tso.c285
1 files changed, 285 insertions, 0 deletions
diff --git a/drivers/s390/net/qeth_tso.c b/drivers/s390/net/qeth_tso.c
new file mode 100644
index 00000000000..c91976274e7
--- /dev/null
+++ b/drivers/s390/net/qeth_tso.c
@@ -0,0 +1,285 @@
+/*
+ * linux/drivers/s390/net/qeth_tso.c ($Revision: 1.6 $)
+ *
+ * Header file for qeth TCP Segmentation Offload support.
+ *
+ * Copyright 2004 IBM Corporation
+ *
+ * Author(s): Frank Pavlic <pavlic@de.ibm.com>
+ *
+ * $Revision: 1.6 $ $Date: 2005/03/24 09:04:18 $
+ *
+ */
+
+#include <linux/skbuff.h>
+#include <linux/tcp.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <net/ip6_checksum.h>
+#include "qeth.h"
+#include "qeth_mpc.h"
+#include "qeth_tso.h"
+
+/**
+ * skb already partially prepared
+ * classic qdio header in skb->data
+ * */
+static inline struct qeth_hdr_tso *
+qeth_tso_prepare_skb(struct qeth_card *card, struct sk_buff **skb)
+{
+ int rc = 0;
+
+ QETH_DBF_TEXT(trace, 5, "tsoprsk");
+ rc = qeth_realloc_headroom(card, skb,sizeof(struct qeth_hdr_ext_tso));
+ if (rc)
+ return NULL;
+
+ return qeth_push_skb(card, skb, sizeof(struct qeth_hdr_ext_tso));
+}
+
+/**
+ * fill header for a TSO packet
+ */
+static inline void
+qeth_tso_fill_header(struct qeth_card *card, struct sk_buff *skb)
+{
+ struct qeth_hdr_tso *hdr;
+ struct tcphdr *tcph;
+ struct iphdr *iph;
+
+ QETH_DBF_TEXT(trace, 5, "tsofhdr");
+
+ hdr = (struct qeth_hdr_tso *) skb->data;
+ iph = skb->nh.iph;
+ tcph = skb->h.th;
+ /*fix header to TSO values ...*/
+ hdr->hdr.hdr.l3.id = QETH_HEADER_TYPE_TSO;
+ /*set values which are fix for the first approach ...*/
+ hdr->ext.hdr_tot_len = (__u16) sizeof(struct qeth_hdr_ext_tso);
+ hdr->ext.imb_hdr_no = 1;
+ hdr->ext.hdr_type = 1;
+ hdr->ext.hdr_version = 1;
+ hdr->ext.hdr_len = 28;
+ /*insert non-fix values */
+ hdr->ext.mss = skb_shinfo(skb)->tso_size;
+ hdr->ext.dg_hdr_len = (__u16)(iph->ihl*4 + tcph->doff*4);
+ hdr->ext.payload_len = (__u16)(skb->len - hdr->ext.dg_hdr_len -
+ sizeof(struct qeth_hdr_tso));
+}
+
+/**
+ * change some header values as requested by hardware
+ */
+static inline void
+qeth_tso_set_tcpip_header(struct qeth_card *card, struct sk_buff *skb)
+{
+ struct iphdr *iph;
+ struct ipv6hdr *ip6h;
+ struct tcphdr *tcph;
+
+ iph = skb->nh.iph;
+ ip6h = skb->nh.ipv6h;
+ tcph = skb->h.th;
+
+ tcph->check = 0;
+ if (skb->protocol == ETH_P_IPV6) {
+ ip6h->payload_len = 0;
+ tcph->check = ~csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+ 0, IPPROTO_TCP, 0);
+ return;
+ }
+ /*OSA want us to set these values ...*/
+ tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
+ 0, IPPROTO_TCP, 0);
+ iph->tot_len = 0;
+ iph->check = 0;
+}
+
+static inline struct qeth_hdr_tso *
+qeth_tso_prepare_packet(struct qeth_card *card, struct sk_buff *skb,
+ int ipv, int cast_type)
+{
+ struct qeth_hdr_tso *hdr;
+ int rc = 0;
+
+ QETH_DBF_TEXT(trace, 5, "tsoprep");
+
+ /*get headroom for tso qdio header */
+ hdr = (struct qeth_hdr_tso *) qeth_tso_prepare_skb(card, &skb);
+ if (hdr == NULL) {
+ QETH_DBF_TEXT_(trace, 4, "2err%d", rc);
+ return NULL;
+ }
+ memset(hdr, 0, sizeof(struct qeth_hdr_tso));
+ /*fill first 32 bytes of qdio header as used
+ *FIXME: TSO has two struct members
+ * with different names but same size
+ * */
+ qeth_fill_header(card, &hdr->hdr, skb, ipv, cast_type);
+ qeth_tso_fill_header(card, skb);
+ qeth_tso_set_tcpip_header(card, skb);
+ return hdr;
+}
+
+static inline int
+qeth_tso_get_queue_buffer(struct qeth_qdio_out_q *queue)
+{
+ struct qeth_qdio_out_buffer *buffer;
+ int flush_cnt = 0;
+
+ QETH_DBF_TEXT(trace, 5, "tsobuf");
+
+ /* force to non-packing*/
+ if (queue->do_pack)
+ queue->do_pack = 0;
+ buffer = &queue->bufs[queue->next_buf_to_fill];
+ /* get a new buffer if current is already in use*/
+ if ((atomic_read(&buffer->state) == QETH_QDIO_BUF_EMPTY) &&
+ (buffer->next_element_to_fill > 0)) {
+ atomic_set(&buffer->state, QETH_QDIO_BUF_PRIMED);
+ queue->next_buf_to_fill = (queue->next_buf_to_fill + 1) %
+ QDIO_MAX_BUFFERS_PER_Q;
+ flush_cnt++;
+ }
+ return flush_cnt;
+}
+
+static inline void
+__qeth_tso_fill_buffer_frag(struct qeth_qdio_out_buffer *buf,
+ struct sk_buff *skb)
+{
+ struct skb_frag_struct *frag;
+ struct qdio_buffer *buffer;
+ int fragno, cnt, element;
+ unsigned long addr;
+
+ QETH_DBF_TEXT(trace, 6, "tsfilfrg");
+
+ /*initialize variables ...*/
+ fragno = skb_shinfo(skb)->nr_frags;
+ buffer = buf->buffer;
+ element = buf->next_element_to_fill;
+ /*fill buffer elements .....*/
+ for (cnt = 0; cnt < fragno; cnt++) {
+ frag = &skb_shinfo(skb)->frags[cnt];
+ addr = (page_to_pfn(frag->page) << PAGE_SHIFT) +
+ frag->page_offset;
+ buffer->element[element].addr = (char *)addr;
+ buffer->element[element].length = frag->size;
+ if (cnt < (fragno - 1))
+ buffer->element[element].flags =
+ SBAL_FLAGS_MIDDLE_FRAG;
+ else
+ buffer->element[element].flags =
+ SBAL_FLAGS_LAST_FRAG;
+ element++;
+ }
+ buf->next_element_to_fill = element;
+}
+
+static inline int
+qeth_tso_fill_buffer(struct qeth_qdio_out_buffer *buf,
+ struct sk_buff *skb)
+{
+ int length, length_here, element;
+ int hdr_len;
+ struct qdio_buffer *buffer;
+ struct qeth_hdr_tso *hdr;
+ char *data;
+
+ QETH_DBF_TEXT(trace, 3, "tsfilbuf");
+
+ /*increment user count and queue skb ...*/
+ atomic_inc(&skb->users);
+ skb_queue_tail(&buf->skb_list, skb);
+
+ /*initialize all variables...*/
+ buffer = buf->buffer;
+ hdr = (struct qeth_hdr_tso *)skb->data;
+ hdr_len = sizeof(struct qeth_hdr_tso) + hdr->ext.dg_hdr_len;
+ data = skb->data + hdr_len;
+ length = skb->len - hdr_len;
+ element = buf->next_element_to_fill;
+ /*fill first buffer entry only with header information */
+ buffer->element[element].addr = skb->data;
+ buffer->element[element].length = hdr_len;
+ buffer->element[element].flags = SBAL_FLAGS_FIRST_FRAG;
+ buf->next_element_to_fill++;
+
+ if (skb_shinfo(skb)->nr_frags > 0) {
+ __qeth_tso_fill_buffer_frag(buf, skb);
+ goto out;
+ }
+
+ /*start filling buffer entries ...*/
+ element++;
+ while (length > 0) {
+ /* length_here is the remaining amount of data in this page */
+ length_here = PAGE_SIZE - ((unsigned long) data % PAGE_SIZE);
+ if (length < length_here)
+ length_here = length;
+ buffer->element[element].addr = data;
+ buffer->element[element].length = length_here;
+ length -= length_here;
+ if (!length)
+ buffer->element[element].flags =
+ SBAL_FLAGS_LAST_FRAG;
+ else
+ buffer->element[element].flags =
+ SBAL_FLAGS_MIDDLE_FRAG;
+ data += length_here;
+ element++;
+ }
+ /*set the buffer to primed ...*/
+ buf->next_element_to_fill = element;
+out:
+ atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
+ return 1;
+}
+
+int
+qeth_tso_send_packet(struct qeth_card *card, struct sk_buff *skb,
+ struct qeth_qdio_out_q *queue, int ipv, int cast_type)
+{
+ int flush_cnt = 0;
+ struct qeth_hdr_tso *hdr;
+ struct qeth_qdio_out_buffer *buffer;
+ int start_index;
+
+ QETH_DBF_TEXT(trace, 3, "tsosend");
+
+ if (!(hdr = qeth_tso_prepare_packet(card, skb, ipv, cast_type)))
+ return -ENOMEM;
+ /*check if skb fits in one SBAL ...*/
+ if (!(qeth_get_elements_no(card, (void*)hdr, skb)))
+ return -EINVAL;
+ /*lock queue, force switching to non-packing and send it ...*/
+ while (atomic_compare_and_swap(QETH_OUT_Q_UNLOCKED,
+ QETH_OUT_Q_LOCKED,
+ &queue->state));
+ start_index = queue->next_buf_to_fill;
+ buffer = &queue->bufs[queue->next_buf_to_fill];
+ /*check if card is too busy ...*/
+ if (atomic_read(&buffer->state) != QETH_QDIO_BUF_EMPTY){
+ card->stats.tx_dropped++;
+ goto out;
+ }
+ /*let's force to non-packing and get a new SBAL*/
+ flush_cnt += qeth_tso_get_queue_buffer(queue);
+ buffer = &queue->bufs[queue->next_buf_to_fill];
+ if (atomic_read(&buffer->state) != QETH_QDIO_BUF_EMPTY) {
+ card->stats.tx_dropped++;
+ goto out;
+ }
+ flush_cnt += qeth_tso_fill_buffer(buffer, skb);
+ queue->next_buf_to_fill = (queue->next_buf_to_fill + 1) %
+ QDIO_MAX_BUFFERS_PER_Q;
+out:
+ atomic_set(&queue->state, QETH_OUT_Q_UNLOCKED);
+ if (flush_cnt)
+ qeth_flush_buffers(queue, 0, start_index, flush_cnt);
+ /*do some statistics */
+ card->stats.tx_packets++;
+ card->stats.tx_bytes += skb->len;
+ return 0;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-02 16:14:00 +0000