target/cxgbit: add T6 iSCSI DDP completion feature

Chelsio T6 adapters reduce number of completion
to host by generating single completion for all
directly placed(DDP) iSCSI pdus in a sequence,
completion contains iSCSI hdr of the last pdu
in a sequence.

On receiving DDP completion cxgbit driver finds
iSCSI cmd using iscsit_find_cmd_from_itt_or_dump(),
then updates cmd->write_data_done, cmd->next_burst_len,
cmd->data_sn and calls __iscsit_check_dataout_hdr()
to validate iSCSI hdr.

(Update __iscsit_check_dataout_hdr parameter usage - nab)
Signed-off-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/iscsi/cxgbit/cxgbit_cm.c

@@ -1114,6 +1114,9 @@ cxgbit_pass_accept_rpl(struct cxgbit_sock *csk, struct cpl_pass_accept_req *req)
 	opt2 = RX_CHANNEL_V(0) |
 		RSS_QUEUE_VALID_F | RSS_QUEUE_V(csk->rss_qid);
 
+	if (!is_t5(lldi->adapter_type))
+		opt2 |= RX_FC_DISABLE_F;
+
 	if (req->tcpopt.tstamp)
 		opt2 |= TSTAMPS_EN_F;
 	if (req->tcpopt.sack)

drivers/target/iscsi/cxgbit/cxgbit_lro.h

@@ -31,8 +31,9 @@ enum cxgbit_pducb_flags {
 	PDUCBF_RX_DATA		= (1 << 1), /* received pdu payload */
 	PDUCBF_RX_STATUS	= (1 << 2), /* received ddp status */
 	PDUCBF_RX_DATA_DDPD	= (1 << 3), /* pdu payload ddp'd */
-	PDUCBF_RX_HCRC_ERR	= (1 << 4), /* header digest error */
-	PDUCBF_RX_DCRC_ERR	= (1 << 5), /* data digest error */
+	PDUCBF_RX_DDP_CMP	= (1 << 4), /* ddp completion */
+	PDUCBF_RX_HCRC_ERR	= (1 << 5), /* header digest error */
+	PDUCBF_RX_DCRC_ERR	= (1 << 6), /* data digest error */
 };
 
 struct cxgbit_lro_pdu_cb {

drivers/target/iscsi/cxgbit/cxgbit_main.c

@@ -165,29 +165,24 @@ static int cxgbit_uld_state_change(void *handle, enum cxgb4_state state)
 }
 
 static void
-cxgbit_proc_ddp_status(unsigned int tid, struct cpl_rx_data_ddp *cpl,
-		       struct cxgbit_lro_pdu_cb *pdu_cb)
+cxgbit_process_ddpvld(struct cxgbit_sock *csk, struct cxgbit_lro_pdu_cb *pdu_cb,
+		      u32 ddpvld)
 {
-	unsigned int status = ntohl(cpl->ddpvld);
 
-	pdu_cb->flags |= PDUCBF_RX_STATUS;
-	pdu_cb->ddigest = ntohl(cpl->ulp_crc);
-	pdu_cb->pdulen = ntohs(cpl->len);
-
-	if (status & (1 << CPL_RX_ISCSI_DDP_STATUS_HCRC_SHIFT)) {
-		pr_info("tid 0x%x, status 0x%x, hcrc bad.\n", tid, status);
+	if (ddpvld & (1 << CPL_RX_ISCSI_DDP_STATUS_HCRC_SHIFT)) {
+		pr_info("tid 0x%x, status 0x%x, hcrc bad.\n", csk->tid, ddpvld);
 		pdu_cb->flags |= PDUCBF_RX_HCRC_ERR;
 	}
 
-	if (status & (1 << CPL_RX_ISCSI_DDP_STATUS_DCRC_SHIFT)) {
-		pr_info("tid 0x%x, status 0x%x, dcrc bad.\n", tid, status);
+	if (ddpvld & (1 << CPL_RX_ISCSI_DDP_STATUS_DCRC_SHIFT)) {
+		pr_info("tid 0x%x, status 0x%x, dcrc bad.\n", csk->tid, ddpvld);
 		pdu_cb->flags |= PDUCBF_RX_DCRC_ERR;
 	}
 
-	if (status & (1 << CPL_RX_ISCSI_DDP_STATUS_PAD_SHIFT))
-		pr_info("tid 0x%x, status 0x%x, pad bad.\n", tid, status);
+	if (ddpvld & (1 << CPL_RX_ISCSI_DDP_STATUS_PAD_SHIFT))
+		pr_info("tid 0x%x, status 0x%x, pad bad.\n", csk->tid, ddpvld);
 
-	if ((status & (1 << CPL_RX_ISCSI_DDP_STATUS_DDP_SHIFT)) &&
+	if ((ddpvld & (1 << CPL_RX_ISCSI_DDP_STATUS_DDP_SHIFT)) &&
 	    (!(pdu_cb->flags & PDUCBF_RX_DATA))) {
 		pdu_cb->flags |= PDUCBF_RX_DATA_DDPD;
 	}
@@ -201,13 +196,17 @@ cxgbit_lro_add_packet_rsp(struct sk_buff *skb, u8 op, const __be64 *rsp)
 						lro_cb->pdu_idx);
 	struct cpl_rx_iscsi_ddp *cpl = (struct cpl_rx_iscsi_ddp *)(rsp + 1);
 
-	cxgbit_proc_ddp_status(lro_cb->csk->tid, cpl, pdu_cb);
+	cxgbit_process_ddpvld(lro_cb->csk, pdu_cb, be32_to_cpu(cpl->ddpvld));
+
+	pdu_cb->flags |= PDUCBF_RX_STATUS;
+	pdu_cb->ddigest = ntohl(cpl->ulp_crc);
+	pdu_cb->pdulen = ntohs(cpl->len);
 
 	if (pdu_cb->flags & PDUCBF_RX_HDR)
 		pdu_cb->complete = true;
 
-	lro_cb->complete = true;
 	lro_cb->pdu_totallen += pdu_cb->pdulen;
+	lro_cb->complete = true;
 	lro_cb->pdu_idx++;
 }
 
@@ -257,7 +256,7 @@ cxgbit_lro_add_packet_gl(struct sk_buff *skb, u8 op, const struct pkt_gl *gl)
 			cxgbit_skcb_flags(skb) = 0;
 
 		lro_cb->complete = false;
-	} else {
+	} else if (op == CPL_ISCSI_DATA) {
 		struct cpl_iscsi_data *cpl = (struct cpl_iscsi_data *)gl->va;
 
 		offset = sizeof(struct cpl_iscsi_data);
@@ -267,6 +266,36 @@ cxgbit_lro_add_packet_gl(struct sk_buff *skb, u8 op, const struct pkt_gl *gl)
 		pdu_cb->doffset = lro_cb->offset;
 		pdu_cb->nr_dfrags = gl->nfrags;
 		pdu_cb->dfrag_idx = skb_shinfo(skb)->nr_frags;
+		lro_cb->complete = false;
+	} else {
+		struct cpl_rx_iscsi_cmp *cpl;
+
+		cpl = (struct cpl_rx_iscsi_cmp *)gl->va;
+		offset = sizeof(struct cpl_rx_iscsi_cmp);
+		pdu_cb->flags |= (PDUCBF_RX_HDR | PDUCBF_RX_STATUS);
+		len = be16_to_cpu(cpl->len);
+		pdu_cb->hdr = gl->va + offset;
+		pdu_cb->hlen = len;
+		pdu_cb->hfrag_idx = skb_shinfo(skb)->nr_frags;
+		pdu_cb->ddigest = be32_to_cpu(cpl->ulp_crc);
+		pdu_cb->pdulen = ntohs(cpl->len);
+
+		if (unlikely(gl->nfrags > 1))
+			cxgbit_skcb_flags(skb) = 0;
+
+		cxgbit_process_ddpvld(lro_cb->csk, pdu_cb,
+				      be32_to_cpu(cpl->ddpvld));
+
+		if (pdu_cb->flags & PDUCBF_RX_DATA_DDPD) {
+			pdu_cb->flags |= PDUCBF_RX_DDP_CMP;
+			pdu_cb->complete = true;
+		} else if (pdu_cb->flags & PDUCBF_RX_DATA) {
+			pdu_cb->complete = true;
+		}
+
+		lro_cb->pdu_totallen += pdu_cb->hlen + pdu_cb->dlen;
+		lro_cb->complete = true;
+		lro_cb->pdu_idx++;
 	}
 
 	cxgbit_copy_frags(skb, gl, offset);
@@ -413,6 +442,7 @@ cxgbit_uld_lro_rx_handler(void *hndl, const __be64 *rsp,
 	switch (op) {
 	case CPL_ISCSI_HDR:
 	case CPL_ISCSI_DATA:
+	case CPL_RX_ISCSI_CMP:
 	case CPL_RX_ISCSI_DDP:
 	case CPL_FW4_ACK:
 		lro_flush = false;
@@ -459,7 +489,8 @@ cxgbit_uld_lro_rx_handler(void *hndl, const __be64 *rsp,
 			return 0;
 		}
 
-		if (op == CPL_ISCSI_HDR || op == CPL_ISCSI_DATA) {
+		if ((op == CPL_ISCSI_HDR) || (op == CPL_ISCSI_DATA) ||
+		    (op == CPL_RX_ISCSI_CMP)) {
 			if (!cxgbit_lro_receive(csk, op, rsp, gl, lro_mgr,
 						napi))
 				return 0;

drivers/target/iscsi/cxgbit/cxgbit_target.c

@@ -1021,11 +1021,36 @@ static int cxgbit_handle_iscsi_dataout(struct cxgbit_sock *csk)
 	int rc, sg_nents, sg_off;
 	bool dcrc_err = false;
 
+	if (pdu_cb->flags & PDUCBF_RX_DDP_CMP) {
+		u32 offset = be32_to_cpu(hdr->offset);
+		u32 ddp_data_len;
+		u32 payload_length = ntoh24(hdr->dlength);
+		bool success = false;
+
+		cmd = iscsit_find_cmd_from_itt_or_dump(conn, hdr->itt, 0);
+		if (!cmd)
+			return 0;
+
+		ddp_data_len = offset - cmd->write_data_done;
+		atomic_long_add(ddp_data_len, &conn->sess->rx_data_octets);
+
+		cmd->write_data_done = offset;
+		cmd->next_burst_len = ddp_data_len;
+		cmd->data_sn = be32_to_cpu(hdr->datasn);
+
+		rc = __iscsit_check_dataout_hdr(conn, (unsigned char *)hdr,
+						cmd, payload_length, &success);
+		if (rc < 0)
+			return rc;
+		else if (!success)
+			return 0;
+	} else {
 		rc = iscsit_check_dataout_hdr(conn, (unsigned char *)hdr, &cmd);
 		if (rc < 0)
 			return rc;
 		else if (!cmd)
 			return 0;
+	}
 
 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
 		pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
@@ -1389,6 +1414,9 @@ static void cxgbit_lro_hskb_reset(struct cxgbit_sock *csk)
 	for (i = 0; i < ssi->nr_frags; i++)
 		put_page(skb_frag_page(&ssi->frags[i]));
 	ssi->nr_frags = 0;
+	skb->data_len = 0;
+	skb->truesize -= skb->len;
+	skb->len = 0;
 }
 
 static void
@@ -1402,39 +1430,42 @@ cxgbit_lro_skb_merge(struct cxgbit_sock *csk, struct sk_buff *skb, u8 pdu_idx)
 	unsigned int len = 0;
 
 	if (pdu_cb->flags & PDUCBF_RX_HDR) {
-		hpdu_cb->flags = pdu_cb->flags;
+		u8 hfrag_idx = hssi->nr_frags;
+
+		hpdu_cb->flags |= pdu_cb->flags;
 		hpdu_cb->seq = pdu_cb->seq;
 		hpdu_cb->hdr = pdu_cb->hdr;
 		hpdu_cb->hlen = pdu_cb->hlen;
 
-		memcpy(&hssi->frags[0], &ssi->frags[pdu_cb->hfrag_idx],
+		memcpy(&hssi->frags[hfrag_idx], &ssi->frags[pdu_cb->hfrag_idx],
 		       sizeof(skb_frag_t));
 
-		get_page(skb_frag_page(&hssi->frags[0]));
-		hssi->nr_frags = 1;
-		hpdu_cb->frags = 1;
-		hpdu_cb->hfrag_idx = 0;
+		get_page(skb_frag_page(&hssi->frags[hfrag_idx]));
+		hssi->nr_frags++;
+		hpdu_cb->frags++;
+		hpdu_cb->hfrag_idx = hfrag_idx;
 
-		len = hssi->frags[0].size;
-		hskb->len = len;
-		hskb->data_len = len;
-		hskb->truesize = len;
+		len = hssi->frags[hfrag_idx].size;
+		hskb->len += len;
+		hskb->data_len += len;
+		hskb->truesize += len;
 	}
 
 	if (pdu_cb->flags & PDUCBF_RX_DATA) {
-		u8 hfrag_idx = 1, i;
+		u8 dfrag_idx = hssi->nr_frags, i;
 
 		hpdu_cb->flags |= pdu_cb->flags;
+		hpdu_cb->dfrag_idx = dfrag_idx;
 
 		len = 0;
-		for (i = 0; i < pdu_cb->nr_dfrags; hfrag_idx++, i++) {
-			memcpy(&hssi->frags[hfrag_idx],
+		for (i = 0; i < pdu_cb->nr_dfrags; dfrag_idx++, i++) {
+			memcpy(&hssi->frags[dfrag_idx],
 			       &ssi->frags[pdu_cb->dfrag_idx + i],
 			       sizeof(skb_frag_t));
 
-			get_page(skb_frag_page(&hssi->frags[hfrag_idx]));
+			get_page(skb_frag_page(&hssi->frags[dfrag_idx]));
 
-			len += hssi->frags[hfrag_idx].size;
+			len += hssi->frags[dfrag_idx].size;
 
 			hssi->nr_frags++;
 			hpdu_cb->frags++;
@@ -1443,7 +1474,6 @@ cxgbit_lro_skb_merge(struct cxgbit_sock *csk, struct sk_buff *skb, u8 pdu_idx)
 		hpdu_cb->dlen = pdu_cb->dlen;
 		hpdu_cb->doffset = hpdu_cb->hlen;
 		hpdu_cb->nr_dfrags = pdu_cb->nr_dfrags;
-		hpdu_cb->dfrag_idx = 1;
 		hskb->len += len;
 		hskb->data_len += len;
 		hskb->truesize += len;
@@ -1528,10 +1558,15 @@ static int cxgbit_rx_lro_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
 
 static int cxgbit_rx_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
 {
+	struct cxgb4_lld_info *lldi = &csk->com.cdev->lldi;
 	int ret = -1;
 
-	if (likely(cxgbit_skcb_flags(skb) & SKCBF_RX_LRO))
+	if (likely(cxgbit_skcb_flags(skb) & SKCBF_RX_LRO)) {
+		if (is_t5(lldi->adapter_type))
 			ret = cxgbit_rx_lro_skb(csk, skb);
+		else
+			ret = cxgbit_process_lro_skb(csk, skb);
+	}
 
 	__kfree_skb(skb);
 	return ret;