SG: Change sg_set_page() to take length and offset argument

Most drivers need to set length and offset as well, so may as well fold
those three lines into one.

Add sg_assign_page() for those two locations that only needed to set
the page, where the offset/length is set outside of the function context.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 4e2c84f..7b7c6c4 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2045,9 +2045,7 @@
 	if (copy > 0) {
 		if (copy > len)
 			copy = len;
-		sg_set_page(&sg[elt], virt_to_page(skb->data + offset));
-		sg[elt].offset = (unsigned long)(skb->data + offset) % PAGE_SIZE;
-		sg[elt].length = copy;
+		sg_set_buf(sg, skb->data + offset, copy);
 		elt++;
 		if ((len -= copy) == 0)
 			return elt;
@@ -2065,9 +2063,8 @@
 
 			if (copy > len)
 				copy = len;
-			sg_set_page(&sg[elt], frag->page);
-			sg[elt].offset = frag->page_offset+offset-start;
-			sg[elt].length = copy;
+			sg_set_page(&sg[elt], frag->page, copy,
+					frag->page_offset+offset-start);
 			elt++;
 			if (!(len -= copy))
 				return elt;
diff --git a/net/ieee80211/ieee80211_crypt_tkip.c b/net/ieee80211/ieee80211_crypt_tkip.c
index 74d0175..4cce353 100644
--- a/net/ieee80211/ieee80211_crypt_tkip.c
+++ b/net/ieee80211/ieee80211_crypt_tkip.c
@@ -537,13 +537,8 @@
 		return -1;
 	}
 	sg_init_table(sg, 2);
-	sg_set_page(&sg[0], virt_to_page(hdr));
-	sg[0].offset = offset_in_page(hdr);
-	sg[0].length = 16;
-
-	sg_set_page(&sg[1], virt_to_page(data));
-	sg[1].offset = offset_in_page(data);
-	sg[1].length = data_len;
+	sg_set_buf(&sg[0], hdr, 16);
+	sg_set_buf(&sg[1], data, data_len);
 
 	if (crypto_hash_setkey(tfm_michael, key, 8))
 		return -1;
diff --git a/net/sctp/auth.c b/net/sctp/auth.c
index cbd64b2..621113a 100644
--- a/net/sctp/auth.c
+++ b/net/sctp/auth.c
@@ -727,9 +727,7 @@
 	/* set up scatter list */
 	end = skb_tail_pointer(skb);
 	sg_init_table(&sg, 1);
-	sg_set_page(&sg, virt_to_page(auth));
-	sg.offset = (unsigned long)(auth) % PAGE_SIZE;
-	sg.length = end - (unsigned char *)auth;
+	sg_set_buf(&sg, auth, end - (unsigned char *)auth);
 
 	desc.tfm = asoc->ep->auth_hmacs[hmac_id];
 	desc.flags = 0;
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 658476c..c055212 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -1514,9 +1514,7 @@
 
 		/* Sign the message.  */
 		sg_init_table(&sg, 1);
-		sg_set_page(&sg, virt_to_page(&cookie->c));
-		sg.offset = (unsigned long)(&cookie->c) % PAGE_SIZE;
-		sg.length = bodysize;
+		sg_set_buf(&sg, &cookie->c, bodysize);
 		keylen = SCTP_SECRET_SIZE;
 		key = (char *)ep->secret_key[ep->current_key];
 		desc.tfm = sctp_sk(ep->base.sk)->hmac;
@@ -1587,9 +1585,7 @@
 	/* Check the signature.  */
 	keylen = SCTP_SECRET_SIZE;
 	sg_init_table(&sg, 1);
-	sg_set_page(&sg, virt_to_page(bear_cookie));
-	sg.offset = (unsigned long)(bear_cookie) % PAGE_SIZE;
-	sg.length = bodysize;
+	sg_set_buf(&sg, bear_cookie, bodysize);
 	key = (char *)ep->secret_key[ep->current_key];
 	desc.tfm = sctp_sk(ep->base.sk)->hmac;
 	desc.flags = 0;
diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c
index 32be431..24711be 100644
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -199,7 +199,7 @@
 	} else {
 		in_page = sg_page(sg);
 	}
-	sg_set_page(&desc->infrags[desc->fragno], in_page);
+	sg_assign_page(&desc->infrags[desc->fragno], in_page);
 	desc->fragno++;
 	desc->fraglen += sg->length;
 	desc->pos += sg->length;
@@ -215,11 +215,10 @@
 	if (ret)
 		return ret;
 	if (fraglen) {
-		sg_set_page(&desc->outfrags[0], sg_page(sg));
-		desc->outfrags[0].offset = sg->offset + sg->length - fraglen;
-		desc->outfrags[0].length = fraglen;
+		sg_set_page(&desc->outfrags[0], sg_page(sg), fraglen,
+				sg->offset + sg->length - fraglen);
 		desc->infrags[0] = desc->outfrags[0];
-		sg_set_page(&desc->infrags[0], in_page);
+		sg_assign_page(&desc->infrags[0], in_page);
 		desc->fragno = 1;
 		desc->fraglen = fraglen;
 	} else {
@@ -287,9 +286,8 @@
 	if (ret)
 		return ret;
 	if (fraglen) {
-		sg_set_page(&desc->frags[0], sg_page(sg));
-		desc->frags[0].offset = sg->offset + sg->length - fraglen;
-		desc->frags[0].length = fraglen;
+		sg_set_page(&desc->frags[0], sg_page(sg), fraglen,
+				sg->offset + sg->length - fraglen);
 		desc->fragno = 1;
 		desc->fraglen = fraglen;
 	} else {
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 3d1f7cd..f38dac3 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -1059,9 +1059,7 @@
 		do {
 			if (thislen > page_len)
 				thislen = page_len;
-			sg_set_page(sg, buf->pages[i]);
-			sg->offset = page_offset;
-			sg->length = thislen;
+			sg_set_page(sg, buf->pages[i], thislen, page_offset);
 			ret = actor(sg, data);
 			if (ret)
 				goto out;
diff --git a/net/xfrm/xfrm_algo.c b/net/xfrm/xfrm_algo.c
index 313d4be..fa45989 100644
--- a/net/xfrm/xfrm_algo.c
+++ b/net/xfrm/xfrm_algo.c
@@ -553,9 +553,7 @@
 		if (copy > len)
 			copy = len;
 
-		sg_set_page(&sg, virt_to_page(skb->data + offset));
-		sg.offset = (unsigned long)(skb->data + offset) % PAGE_SIZE;
-		sg.length = copy;
+		sg_set_buf(&sg, skb->data + offset, copy);
 
 		err = icv_update(desc, &sg, copy);
 		if (unlikely(err))
@@ -578,9 +576,8 @@
 			if (copy > len)
 				copy = len;
 
-			sg_set_page(&sg, frag->page);
-			sg.offset = frag->page_offset + offset-start;
-			sg.length = copy;
+			sg_set_page(&sg, frag->page, copy,
+					frag->page_offset + offset-start);
 
 			err = icv_update(desc, &sg, copy);
 			if (unlikely(err))