iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

s390/qeth: prepare for copy-free TSO transmission

Browse Source 
Add all the necessary TSO plumbing to the copy-less transmit path.
This includes calculating the right length of required protocol headers,
and always building a separate buffer element for the TSO headers.

A follow-up patch will then switch TSO traffic over to this path.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Julian Wiedmann 2018-09-17 17:36:02 +02:00 committed by David S. Miller
parent 5549426466
commit e517b649b3
4 changed files with 77 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/s390/net/qeth_core.h
View File

@ -26,6 +26,7 @@
#include <net/ipv6.h>
#include <net/if_inet6.h>
#include <net/addrconf.h>
#include <net/tcp.h>
#include <asm/debug.h>
#include <asm/qdio.h>

10
drivers/s390/net/qeth_core_main.c
View File

@ -3845,7 +3845,8 @@ int qeth_hdr_chk_and_bounce(struct sk_buff *skb, struct qeth_hdr **hdr, int len)
}
EXPORT_SYMBOL_GPL(qeth_hdr_chk_and_bounce);
#define QETH_HDR_CACHE_OBJ_SIZE (sizeof(struct qeth_hdr) + ETH_HLEN)
#define QETH_HDR_CACHE_OBJ_SIZE (sizeof(struct qeth_hdr_tso) + \
MAX_TCP_HEADER)
/**
* qeth_add_hw_header() - add a HW header to an skb.
@ -3880,7 +3881,11 @@ check_layout:
if (qeth_get_elements_for_range(start, end + contiguous) == 1) {
/* Push HW header into same page as first protocol header. */
push_ok = true;
__elements = qeth_count_elements(skb, 0);
/* ... but TSO always needs a separate element for headers: */
if (skb_is_gso(skb))
__elements = 1 + qeth_count_elements(skb, proto_len);
else
__elements = qeth_count_elements(skb, 0);
} else if (!proto_len && qeth_get_elements_for_range(start, end) == 1) {
/* Push HW header into a new page. */
push_ok = true;
@ -4193,6 +4198,7 @@ int qeth_xmit(struct qeth_card *card, struct sk_buff *skb,
hd_len = hw_hdr_len + proto_len;
data_offset = proto_len;
}
memset(hdr, 0, hw_hdr_len);
fill_header(card, hdr, skb, ipv, cast_type, frame_len);
is_sg = skb_is_nonlinear(skb);

1
drivers/s390/net/qeth_l2_main.c
View File

@ -199,7 +199,6 @@ static void qeth_l2_fill_header(struct qeth_card *card, struct qeth_hdr *hdr,
{
struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb_mac_header(skb);
memset(hdr, 0, sizeof(struct qeth_hdr));
hdr->hdr.l2.id = QETH_HEADER_TYPE_LAYER2;
hdr->hdr.l2.pkt_length = data_len;

93
drivers/s390/net/qeth_l3_main.c
View File

@ -2008,7 +2008,6 @@ static void qeth_l3_fill_af_iucv_hdr(struct qeth_hdr *hdr, struct sk_buff *skb,
char daddr[16];
struct af_iucv_trans_hdr *iucv_hdr;
memset(hdr, 0, sizeof(struct qeth_hdr));
hdr->hdr.l3.id = QETH_HEADER_TYPE_LAYER3;
hdr->hdr.l3.length = data_len;
hdr->hdr.l3.flags = QETH_HDR_IPV6 | QETH_CAST_UNICAST;
@ -2038,10 +2037,22 @@ static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr,
{
struct vlan_ethhdr *veth = vlan_eth_hdr(skb);
memset(hdr, 0, sizeof(struct qeth_hdr));
hdr->hdr.l3.id = QETH_HEADER_TYPE_LAYER3;
hdr->hdr.l3.length = data_len;
if (skb_is_gso(skb)) {
hdr->hdr.l3.id = QETH_HEADER_TYPE_TSO;
} else {
hdr->hdr.l3.id = QETH_HEADER_TYPE_LAYER3;
if (skb->ip_summed == CHECKSUM_PARTIAL) {
qeth_tx_csum(skb, &hdr->hdr.l3.ext_flags, ipv);
/* some HW requires combined L3+L4 csum offload: */
if (ipv == 4)
hdr->hdr.l3.ext_flags |= QETH_HDR_EXT_CSUM_HDR_REQ;
if (card->options.performance_stats)
card->perf_stats.tx_csum++;
}
}
if (ipv == 4 || IS_IQD(card)) {
/* NETIF_F_HW_VLAN_CTAG_TX */
if (skb_vlan_tag_present(skb)) {
@ -2053,15 +2064,6 @@ static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr,
hdr->hdr.l3.vlan_id = ntohs(veth->h_vlan_TCI);
}
if (!skb_is_gso(skb) && skb->ip_summed == CHECKSUM_PARTIAL) {
qeth_tx_csum(skb, &hdr->hdr.l3.ext_flags, ipv);
/* some HW requires combined L3+L4 csum offload: */
if (ipv == 4)
hdr->hdr.l3.ext_flags |= QETH_HDR_EXT_CSUM_HDR_REQ;
if (card->options.performance_stats)
card->perf_stats.tx_csum++;
}
/* OSA only: */
if (!ipv) {
hdr->hdr.l3.flags = QETH_HDR_PASSTHRU;
@ -2100,6 +2102,22 @@ static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr,
rcu_read_unlock();
}
static void qeth_l3_fill_tso_ext(struct qeth_hdr_tso *hdr,
unsigned int payload_len, struct sk_buff *skb,
unsigned int proto_len)
{
struct qeth_hdr_ext_tso *ext = &hdr->ext;
ext->hdr_tot_len = sizeof(*ext);
ext->imb_hdr_no = 1;
ext->hdr_type = 1;
ext->hdr_version = 1;
ext->hdr_len = 28;
ext->payload_len = payload_len;
ext->mss = skb_shinfo(skb)->gso_size;
ext->dg_hdr_len = proto_len;
}
static void qeth_tso_fill_header(struct qeth_card *card,
struct qeth_hdr *qhdr, struct sk_buff *skb)
{
@ -2108,8 +2126,6 @@ static void qeth_tso_fill_header(struct qeth_card *card,
struct iphdr *iph = ip_hdr(skb);
struct ipv6hdr *ip6h = ipv6_hdr(skb);
/*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;
@ -2173,20 +2189,35 @@ static void qeth_l3_fixup_headers(struct sk_buff *skb)
/* this is safe, IPv6 traffic takes a different path */
if (skb->ip_summed == CHECKSUM_PARTIAL)
iph->check = 0;
if (skb_is_gso(skb)) {
iph->tot_len = 0;
tcp_hdr(skb)->check = ~tcp_v4_check(0, iph->saddr,
iph->daddr, 0);
}
}
static int qeth_l3_xmit_offload(struct qeth_card *card, struct sk_buff *skb,
struct qeth_qdio_out_q *queue, int ipv,
int cast_type)
{
const unsigned int hw_hdr_len = sizeof(struct qeth_hdr);
unsigned int frame_len, elements;
unsigned int hw_hdr_len, proto_len, frame_len, elements;
unsigned char eth_hdr[ETH_HLEN];
bool is_tso = skb_is_gso(skb);
unsigned int data_offset = 0;
struct qeth_hdr *hdr = NULL;
unsigned int hd_len = 0;
int push_len, rc;
bool is_sg;
if (is_tso) {
hw_hdr_len = sizeof(struct qeth_hdr_tso);
proto_len = skb_transport_offset(skb) + tcp_hdrlen(skb) -
ETH_HLEN;
} else {
hw_hdr_len = sizeof(struct qeth_hdr);
proto_len = 0;
}
/* re-use the L2 header area for the HW header: */
rc = skb_cow_head(skb, hw_hdr_len - ETH_HLEN);
if (rc)
@ -2196,28 +2227,36 @@ static int qeth_l3_xmit_offload(struct qeth_card *card, struct sk_buff *skb,
frame_len = skb->len;
qeth_l3_fixup_headers(skb);
push_len = qeth_add_hw_header(card, skb, &hdr, hw_hdr_len, 0,
push_len = qeth_add_hw_header(card, skb, &hdr, hw_hdr_len, proto_len,
&elements);
if (push_len < 0)
return push_len;
if (!push_len) {
/* hdr was added discontiguous from skb->data */
hd_len = hw_hdr_len;
if (is_tso || !push_len) {
/* HW header needs its own buffer element. */
hd_len = hw_hdr_len + proto_len;
data_offset = push_len + proto_len;
}
memset(hdr, 0, hw_hdr_len);
if (skb->protocol == htons(ETH_P_AF_IUCV))
if (skb->protocol == htons(ETH_P_AF_IUCV)) {
qeth_l3_fill_af_iucv_hdr(hdr, skb, frame_len);
else
} else {
qeth_l3_fill_header(card, hdr, skb, ipv, cast_type, frame_len);
if (is_tso)
qeth_l3_fill_tso_ext((struct qeth_hdr_tso *) hdr,
frame_len - proto_len, skb,
proto_len);
}
is_sg = skb_is_nonlinear(skb);
if (IS_IQD(card)) {
rc = qeth_do_send_packet_fast(queue, skb, hdr, 0, hd_len);
rc = qeth_do_send_packet_fast(queue, skb, hdr, data_offset,
hd_len);
} else {
/* TODO: drop skb_orphan() once TX completion is fast enough */
skb_orphan(skb);
rc = qeth_do_send_packet(card, queue, skb, hdr, 0, hd_len,
elements);
rc = qeth_do_send_packet(card, queue, skb, hdr, data_offset,
hd_len, elements);
}
if (!rc) {
@ -2225,6 +2264,10 @@ static int qeth_l3_xmit_offload(struct qeth_card *card, struct sk_buff *skb,
card->perf_stats.buf_elements_sent += elements;
if (is_sg)
card->perf_stats.sg_skbs_sent++;
if (is_tso) {
card->perf_stats.large_send_bytes += frame_len;
card->perf_stats.large_send_cnt++;
}
}
} else {
if (!push_len)