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author | Ezequiel Garcia <ezequiel.garcia@free-electrons.com> | 2014-05-19 13:59:52 -0300 |
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committer | David S. Miller <davem@davemloft.net> | 2014-05-22 14:57:15 -0400 |
commit | e876f208af18b074f800656e4d1b99da75b2135f (patch) | |
tree | daff9963d9fe03343b9dcac38d0dec07881d1db7 /net | |
parent | 8af750d739620a0028dc767b289b0ed1d61fb38b (diff) | |
download | linux-e876f208af18b074f800656e4d1b99da75b2135f.tar.gz linux-e876f208af18b074f800656e4d1b99da75b2135f.tar.bz2 linux-e876f208af18b074f800656e4d1b99da75b2135f.zip |
net: Add a software TSO helper API
Although the implementation probably needs a lot of work, this initial API
allows to implement software TSO in mvneta and mv643xx_eth drivers in a not
so intrusive way.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r-- | net/core/Makefile | 2 | ||||
-rw-r--r-- | net/core/tso.c | 72 |
2 files changed, 73 insertions, 1 deletions
diff --git a/net/core/Makefile b/net/core/Makefile index 826b925aa453..71093d94ad2b 100644 --- a/net/core/Makefile +++ b/net/core/Makefile @@ -9,7 +9,7 @@ obj-$(CONFIG_SYSCTL) += sysctl_net_core.o obj-y += dev.o ethtool.o dev_addr_lists.o dst.o netevent.o \ neighbour.o rtnetlink.o utils.o link_watch.o filter.o \ - sock_diag.o dev_ioctl.o + sock_diag.o dev_ioctl.o tso.o obj-$(CONFIG_XFRM) += flow.o obj-y += net-sysfs.o diff --git a/net/core/tso.c b/net/core/tso.c new file mode 100644 index 000000000000..097821dd3a8c --- /dev/null +++ b/net/core/tso.c @@ -0,0 +1,72 @@ +#include <net/ip.h> +#include <net/tso.h> + +/* Calculate expected number of TX descriptors */ +int tso_count_descs(struct sk_buff *skb) +{ + /* The Marvell Way */ + return skb_shinfo(skb)->gso_segs * 2 + skb_shinfo(skb)->nr_frags; +} + +void tso_build_hdr(struct sk_buff *skb, char *hdr, struct tso_t *tso, + int size, bool is_last) +{ + struct iphdr *iph; + struct tcphdr *tcph; + int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb); + int mac_hdr_len = skb_network_offset(skb); + + memcpy(hdr, skb->data, hdr_len); + iph = (struct iphdr *)(hdr + mac_hdr_len); + iph->id = htons(tso->ip_id); + iph->tot_len = htons(size + hdr_len - mac_hdr_len); + tcph = (struct tcphdr *)(hdr + skb_transport_offset(skb)); + tcph->seq = htonl(tso->tcp_seq); + tso->ip_id++; + + if (!is_last) { + /* Clear all special flags for not last packet */ + tcph->psh = 0; + tcph->fin = 0; + tcph->rst = 0; + } +} + +void tso_build_data(struct sk_buff *skb, struct tso_t *tso, int size) +{ + tso->tcp_seq += size; + tso->size -= size; + tso->data += size; + + if ((tso->size == 0) && + (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) { + skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx]; + + /* Move to next segment */ + tso->size = frag->size; + tso->data = page_address(frag->page.p) + frag->page_offset; + tso->next_frag_idx++; + } +} + +void tso_start(struct sk_buff *skb, struct tso_t *tso) +{ + int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb); + + tso->ip_id = ntohs(ip_hdr(skb)->id); + tso->tcp_seq = ntohl(tcp_hdr(skb)->seq); + tso->next_frag_idx = 0; + + /* Build first data */ + tso->size = skb_headlen(skb) - hdr_len; + tso->data = skb->data + hdr_len; + if ((tso->size == 0) && + (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) { + skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx]; + + /* Move to next segment */ + tso->size = frag->size; + tso->data = page_address(frag->page.p) + frag->page_offset; + tso->next_frag_idx++; + } +} |