int cxgb3i_conn_init_pdu(struct iscsi_task *task, unsigned int offset,
unsigned int count)
{
struct iscsi_conn *conn = task->conn;
struct iscsi_tcp_task *tcp_task = task->dd_data;
struct cxgb3i_task_data *tdata = tcp_task->dd_data;
struct sk_buff *skb = tdata->skb;
unsigned int datalen = count;
int i, padlen = iscsi_padding(count);
struct page *pg;
cxgb3i_tx_debug("task 0x%p,0x%p, offset %u, count %u, skb 0x%p.\n",
task, task->sc, offset, count, skb);
skb_put(skb, task->hdr_len);
tx_skb_setmode(skb, conn->hdrdgst_en, datalen ? conn->datadgst_en : 0);
if (!count)
return 0;
if (task->sc) {
struct scsi_data_buffer *sdb = scsi_out(task->sc);
struct scatterlist *sg = NULL;
int err;
tdata->offset = offset;
tdata->count = count;
err = sgl_seek_offset(sdb->table.sgl, sdb->table.nents,
tdata->offset, &tdata->sgoffset, &sg);
if (err < 0) {
cxgb3i_log_warn("tpdu, sgl %u, bad offset %u/%u.\n",
sdb->table.nents, tdata->offset,
sdb->length);
return err;
}
err = sgl_read_to_frags(sg, tdata->sgoffset, tdata->count,
tdata->frags, MAX_PDU_FRAGS);
if (err < 0) {
cxgb3i_log_warn("tpdu, sgl %u, bad offset %u + %u.\n",
sdb->table.nents, tdata->offset,
tdata->count);
return err;
}
tdata->nr_frags = err;
if (tdata->nr_frags > MAX_SKB_FRAGS ||
(padlen && tdata->nr_frags == MAX_SKB_FRAGS)) {
char *dst = skb->data + task->hdr_len;
skb_frag_t *frag = tdata->frags;
/* data fits in the skb's headroom */
for (i = 0; i < tdata->nr_frags; i++, frag++) {
char *src = kmap_atomic(frag->page,
KM_SOFTIRQ0);
memcpy(dst, src+frag->page_offset, frag->size);
dst += frag->size;
kunmap_atomic(src, KM_SOFTIRQ0);
}
if (padlen) {
memset(dst, 0, padlen);
padlen = 0;
}
skb_put(skb, count + padlen);
} else {
/* data fit into frag_list */
for (i = 0; i < tdata->nr_frags; i++)
get_page(tdata->frags[i].page);
memcpy(skb_shinfo(skb)->frags, tdata->frags,
sizeof(skb_frag_t) * tdata->nr_frags);
skb_shinfo(skb)->nr_frags = tdata->nr_frags;
skb->len += count;
skb->data_len += count;
skb->truesize += count;
}
} else {
pg = virt_to_page(task->data);
get_page(pg);
skb_fill_page_desc(skb, 0, pg, offset_in_page(task->data),
count);
skb->len += count;
skb->data_len += count;
skb->truesize += count;
}
if (padlen) {
i = skb_shinfo(skb)->nr_frags;
get_page(pad_page);
skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, pad_page, 0,
padlen);
skb->data_len += padlen;
skb->truesize += padlen;
skb->len += padlen;
}
return 0;
}
/**
* iscsi_tcp_segment_done - check whether the segment is complete
* @tcp_conn: iscsi tcp connection
* @segment: iscsi segment to check
* @recv: set to one of this is called from the recv path
* @copied: number of bytes copied
*
* Check if we're done receiving this segment. If the receive
* buffer is full but we expect more data, move on to the
* next entry in the scatterlist.
*
* If the amount of data we received isn't a multiple of 4,
* we will transparently receive the pad bytes, too.
*
* This function must be re-entrant.
*/
int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn,
struct iscsi_segment *segment, int recv,
unsigned copied)
{
struct scatterlist sg;
unsigned int pad;
ISCSI_DBG_TCP(tcp_conn->iscsi_conn, "copied %u %u size %u %s\n",
segment->copied, copied, segment->size,
recv ? "recv" : "xmit");
if (segment->hash && copied) {
/*
* If a segment is kmapd we must unmap it before sending
* to the crypto layer since that will try to kmap it again.
*/
iscsi_tcp_segment_unmap(segment);
if (!segment->data) {
sg_init_table(&sg, 1);
sg_set_page(&sg, sg_page(segment->sg), copied,
segment->copied + segment->sg_offset +
segment->sg->offset);
} else
sg_init_one(&sg, segment->data + segment->copied,
copied);
crypto_hash_update(segment->hash, &sg, copied);
}
segment->copied += copied;
if (segment->copied < segment->size) {
iscsi_tcp_segment_map(segment, recv);
return 0;
}
segment->total_copied += segment->copied;
segment->copied = 0;
segment->size = 0;
/* Unmap the current scatterlist page, if there is one. */
iscsi_tcp_segment_unmap(segment);
/* Do we have more scatterlist entries? */
ISCSI_DBG_TCP(tcp_conn->iscsi_conn, "total copied %u total size %u\n",
segment->total_copied, segment->total_size);
if (segment->total_copied < segment->total_size) {
/* Proceed to the next entry in the scatterlist. */
iscsi_tcp_segment_init_sg(segment, sg_next(segment->sg),
0);
iscsi_tcp_segment_map(segment, recv);
BUG_ON(segment->size == 0);
return 0;
}
/* Do we need to handle padding? */
if (!(tcp_conn->iscsi_conn->session->tt->caps & CAP_PADDING_OFFLOAD)) {
pad = iscsi_padding(segment->total_copied);
if (pad != 0) {
ISCSI_DBG_TCP(tcp_conn->iscsi_conn,
"consume %d pad bytes\n", pad);
segment->total_size += pad;
segment->size = pad;
segment->data = segment->padbuf;
return 0;
}
}
/*
* Set us up for transferring the data digest. hdr digest
* is completely handled in hdr done function.
*/
if (segment->hash) {
crypto_hash_final(segment->hash, segment->digest);
iscsi_tcp_segment_splice_digest(segment,
recv ? segment->recv_digest : segment->digest);
return 0;
}
return 1;
}
