Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e876f208 authored by Ezequiel Garcia's avatar Ezequiel Garcia Committed by David S. Miller
Browse files

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: default avatarEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8af750d7

include/net/tso.h

0 → 100644
+20 −0
Original line number Diff line number Diff line 
#ifndef _TSO_H

#define _TSO_H



#include <net/ip.h>



struct tso_t {

	int next_frag_idx;

	void *data;

	size_t size;

	u16 ip_id;

	u32 tcp_seq;

};



int tso_count_descs(struct sk_buff *skb);

void tso_build_hdr(struct sk_buff *skb, char *hdr, struct tso_t *tso,

		   int size, bool is_last);

void tso_build_data(struct sk_buff *skb, struct tso_t *tso, int size);

void tso_start(struct sk_buff *skb, struct tso_t *tso);



#endif	/* _TSO_H */

net/core/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -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

net/core/tso.c

0 → 100644
+72 −0
Original line number Diff line number Diff line 
#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++;

	}

}