Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 78 insertions, 0 deletions

diff --git a/kernel/net/core/tso.c b/kernel/net/core/tso.c
new file mode 100644
index 000000000..630b30b4f
--- /dev/null
+++ b/kernel/net/core/tso.c
@@ -0,0 +1,78 @@
+#include <linux/export.h>
+#include <net/ip.h>
+#include <net/tso.h>
+#include <asm/unaligned.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;
+}
+EXPORT_SYMBOL(tso_count_descs);
+
+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));
+	put_unaligned_be32(tso->tcp_seq, &tcph->seq);
+	tso->ip_id++;
+
+	if (!is_last) {
+		/* Clear all special flags for not last packet */
+		tcph->psh = 0;
+		tcph->fin = 0;
+		tcph->rst = 0;
+	}
+}
+EXPORT_SYMBOL(tso_build_hdr);
+
+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++;
+	}
+}
+EXPORT_SYMBOL(tso_build_data);
+
+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++;
+	}
+}
+EXPORT_SYMBOL(tso_start);