Merge branch 'sched/core' into sched/cleanups

9 files changed, 354 insertions, 169 deletions

diff --git a/drivers/scsi/cxgb3i/cxgb3i.h b/drivers/scsi/cxgb3i/cxgb3i.h
index fde6e4c634e..a7cf550b9cc 100644
--- a/drivers/scsi/cxgb3i/cxgb3i.h
+++ b/drivers/scsi/cxgb3i/cxgb3i.h
@@ -20,6 +20,7 @@
 #include <linux/list.h>
 #include <linux/netdevice.h>
 #include <linux/scatterlist.h>
+#include <linux/skbuff.h>
 #include <scsi/libiscsi_tcp.h>
 
 /* from cxgb3 LLD */
@@ -113,6 +114,26 @@ struct cxgb3i_endpoint {
 	struct cxgb3i_conn *cconn;
 };
 
+/**
+ * struct cxgb3i_task_data - private iscsi task data
+ *
+ * @nr_frags:	# of coalesced page frags (from scsi sgl)
+ * @frags:	coalesced page frags (from scsi sgl)
+ * @skb:	tx pdu skb
+ * @offset:	data offset for the next pdu
+ * @count:	max. possible pdu payload
+ * @sgoffset:	offset to the first sg entry for a given offset
+ */
+#define MAX_PDU_FRAGS	((ULP2_MAX_PDU_PAYLOAD + 512 - 1) / 512)
+struct cxgb3i_task_data {
+	unsigned short nr_frags;
+	skb_frag_t frags[MAX_PDU_FRAGS];
+	struct sk_buff *skb;
+	unsigned int offset;
+	unsigned int count;
+	unsigned int sgoffset;
+};
+
 int cxgb3i_iscsi_init(void);
 void cxgb3i_iscsi_cleanup(void);
 
diff --git a/drivers/scsi/cxgb3i/cxgb3i_ddp.c b/drivers/scsi/cxgb3i/cxgb3i_ddp.c
index 08f3a09d923..a83d36e4926 100644
--- a/drivers/scsi/cxgb3i/cxgb3i_ddp.c
+++ b/drivers/scsi/cxgb3i/cxgb3i_ddp.c
@@ -639,10 +639,11 @@ static int ddp_init(struct t3cdev *tdev)
 	write_unlock(&cxgb3i_ddp_rwlock);
 
 	ddp_log_info("nppods %u (0x%x ~ 0x%x), bits %u, mask 0x%x,0x%x "
-			"pkt %u,%u.\n",
+			"pkt %u/%u, %u/%u.\n",
 			ppmax, ddp->llimit, ddp->ulimit, ddp->idx_bits,
 			ddp->idx_mask, ddp->rsvd_tag_mask,
-			ddp->max_txsz, ddp->max_rxsz);
+			ddp->max_txsz, uinfo.max_txsz,
+			ddp->max_rxsz, uinfo.max_rxsz);
 	return 0;
 
 free_ddp_map:
@@ -654,8 +655,8 @@ free_ddp_map:
  * cxgb3i_adapter_ddp_init - initialize the adapter's ddp resource
  * @tdev: t3cdev adapter
  * @tformat: tag format
- * @txsz: max tx pkt size, filled in by this func.
- * @rxsz: max rx pkt size, filled in by this func.
+ * @txsz: max tx pdu payload size, filled in by this func.
+ * @rxsz: max rx pdu payload size, filled in by this func.
  * initialize the ddp pagepod manager for a given adapter if needed and
  * setup the tag format for a given iscsi entity
  */
@@ -685,10 +686,12 @@ int cxgb3i_adapter_ddp_init(struct t3cdev *tdev,
 		      tformat->sw_bits, tformat->rsvd_bits,
 		      tformat->rsvd_shift, tformat->rsvd_mask);
 
-	*txsz = ddp->max_txsz;
-	*rxsz = ddp->max_rxsz;
-	ddp_log_info("ddp max pkt size: %u, %u.\n",
-		     ddp->max_txsz, ddp->max_rxsz);
+	*txsz = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
+			ddp->max_txsz - ISCSI_PDU_NONPAYLOAD_LEN);
+	*rxsz = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
+			ddp->max_rxsz - ISCSI_PDU_NONPAYLOAD_LEN);
+	ddp_log_info("max payload size: %u/%u, %u/%u.\n",
+		     *txsz, ddp->max_txsz, *rxsz, ddp->max_rxsz);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(cxgb3i_adapter_ddp_init);
diff --git a/drivers/scsi/cxgb3i/cxgb3i_ddp.h b/drivers/scsi/cxgb3i/cxgb3i_ddp.h
index 5c7c4d95c49..3faae7831c8 100644
--- a/drivers/scsi/cxgb3i/cxgb3i_ddp.h
+++ b/drivers/scsi/cxgb3i/cxgb3i_ddp.h
@@ -13,6 +13,8 @@
 #ifndef __CXGB3I_ULP2_DDP_H__
 #define __CXGB3I_ULP2_DDP_H__
 
+#include <linux/vmalloc.h>
+
 /**
  * struct cxgb3i_tag_format - cxgb3i ulp tag format for an iscsi entity
  *
@@ -85,8 +87,9 @@ struct cxgb3i_ddp_info {
 	struct sk_buff **gl_skb;
 };
 
+#define ISCSI_PDU_NONPAYLOAD_LEN	312 /* bhs(48) + ahs(256) + digest(8) */
 #define ULP2_MAX_PKT_SIZE	16224
-#define ULP2_MAX_PDU_PAYLOAD	(ULP2_MAX_PKT_SIZE - ISCSI_PDU_NONPAYLOAD_MAX)
+#define ULP2_MAX_PDU_PAYLOAD	(ULP2_MAX_PKT_SIZE - ISCSI_PDU_NONPAYLOAD_LEN)
 #define PPOD_PAGES_MAX		4
 #define PPOD_PAGES_SHIFT	2	/* 4 pages per pod */
 
diff --git a/drivers/scsi/cxgb3i/cxgb3i_init.c b/drivers/scsi/cxgb3i/cxgb3i_init.c
index 091ecb4d9f3..1ce9f244e46 100644
--- a/drivers/scsi/cxgb3i/cxgb3i_init.c
+++ b/drivers/scsi/cxgb3i/cxgb3i_init.c
@@ -12,8 +12,8 @@
 #include "cxgb3i.h"
 
 #define DRV_MODULE_NAME         "cxgb3i"
-#define DRV_MODULE_VERSION	"1.0.0"
-#define DRV_MODULE_RELDATE	"Jun. 1, 2008"
+#define DRV_MODULE_VERSION	"1.0.1"
+#define DRV_MODULE_RELDATE	"Jan. 2009"
 
 static char version[] =
 	"Chelsio S3xx iSCSI Driver " DRV_MODULE_NAME
diff --git a/drivers/scsi/cxgb3i/cxgb3i_iscsi.c b/drivers/scsi/cxgb3i/cxgb3i_iscsi.c
index d83464b9b3f..fa2a44f37b3 100644
--- a/drivers/scsi/cxgb3i/cxgb3i_iscsi.c
+++ b/drivers/scsi/cxgb3i/cxgb3i_iscsi.c
@@ -364,7 +364,8 @@ cxgb3i_session_create(struct iscsi_endpoint *ep, u16 cmds_max, u16 qdepth,
 
 	cls_session = iscsi_session_setup(&cxgb3i_iscsi_transport, shost,
 					  cmds_max,
-					  sizeof(struct iscsi_tcp_task),
+					  sizeof(struct iscsi_tcp_task) +
+					  sizeof(struct cxgb3i_task_data),
 					  initial_cmdsn, ISCSI_MAX_TARGET);
 	if (!cls_session)
 		return NULL;
@@ -402,17 +403,15 @@ static inline int cxgb3i_conn_max_xmit_dlength(struct iscsi_conn *conn)
 {
 	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 	struct cxgb3i_conn *cconn = tcp_conn->dd_data;
-	unsigned int max = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
-				 cconn->hba->snic->tx_max_size -
-				 ISCSI_PDU_NONPAYLOAD_MAX);
+	unsigned int max = max(512 * MAX_SKB_FRAGS, SKB_TX_HEADROOM);
 
+	max = min(cconn->hba->snic->tx_max_size, max);
 	if (conn->max_xmit_dlength)
-		conn->max_xmit_dlength = min_t(unsigned int,
-						conn->max_xmit_dlength, max);
+		conn->max_xmit_dlength = min(conn->max_xmit_dlength, max);
 	else
 		conn->max_xmit_dlength = max;
 	align_pdu_size(conn->max_xmit_dlength);
-	cxgb3i_log_info("conn 0x%p, max xmit %u.\n",
+	cxgb3i_api_debug("conn 0x%p, max xmit %u.\n",
 			 conn, conn->max_xmit_dlength);
 	return 0;
 }
@@ -427,9 +426,7 @@ static inline int cxgb3i_conn_max_recv_dlength(struct iscsi_conn *conn)
 {
 	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 	struct cxgb3i_conn *cconn = tcp_conn->dd_data;
-	unsigned int max = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
-				 cconn->hba->snic->rx_max_size -
-				 ISCSI_PDU_NONPAYLOAD_MAX);
+	unsigned int max = cconn->hba->snic->rx_max_size;
 
 	align_pdu_size(max);
 	if (conn->max_recv_dlength) {
@@ -439,8 +436,7 @@ static inline int cxgb3i_conn_max_recv_dlength(struct iscsi_conn *conn)
 					 conn->max_recv_dlength, max);
 			return -EINVAL;
 		}
-		conn->max_recv_dlength = min_t(unsigned int,
-						conn->max_recv_dlength, max);
+		conn->max_recv_dlength = min(conn->max_recv_dlength, max);
 		align_pdu_size(conn->max_recv_dlength);
 	} else
 		conn->max_recv_dlength = max;
@@ -844,7 +840,7 @@ static struct scsi_host_template cxgb3i_host_template = {
 	.proc_name		= "cxgb3i",
 	.queuecommand		= iscsi_queuecommand,
 	.change_queue_depth	= iscsi_change_queue_depth,
-	.can_queue		= 128 * (ISCSI_DEF_XMIT_CMDS_MAX - 1),
+	.can_queue		= CXGB3I_SCSI_QDEPTH_DFLT - 1,
 	.sg_tablesize		= SG_ALL,
 	.max_sectors		= 0xFFFF,
 	.cmd_per_lun		= ISCSI_DEF_CMD_PER_LUN,
diff --git a/drivers/scsi/cxgb3i/cxgb3i_offload.c b/drivers/scsi/cxgb3i/cxgb3i_offload.c
index a865f1fefe8..de3b3b614cc 100644
--- a/drivers/scsi/cxgb3i/cxgb3i_offload.c
+++ b/drivers/scsi/cxgb3i/cxgb3i_offload.c
@@ -23,19 +23,19 @@
 #include "cxgb3i_ddp.h"
 
 #ifdef __DEBUG_C3CN_CONN__
-#define c3cn_conn_debug         cxgb3i_log_info
+#define c3cn_conn_debug		cxgb3i_log_debug
 #else
 #define c3cn_conn_debug(fmt...)
 #endif
 
 #ifdef __DEBUG_C3CN_TX__
-#define c3cn_tx_debug         cxgb3i_log_debug
+#define c3cn_tx_debug		cxgb3i_log_debug
 #else
 #define c3cn_tx_debug(fmt...)
 #endif
 
 #ifdef __DEBUG_C3CN_RX__
-#define c3cn_rx_debug         cxgb3i_log_debug
+#define c3cn_rx_debug		cxgb3i_log_debug
 #else
 #define c3cn_rx_debug(fmt...)
 #endif
@@ -47,9 +47,9 @@ static int cxgb3_rcv_win = 256 * 1024;
 module_param(cxgb3_rcv_win, int, 0644);
 MODULE_PARM_DESC(cxgb3_rcv_win, "TCP receive window in bytes (default=256KB)");
 
-static int cxgb3_snd_win = 64 * 1024;
+static int cxgb3_snd_win = 128 * 1024;
 module_param(cxgb3_snd_win, int, 0644);
-MODULE_PARM_DESC(cxgb3_snd_win, "TCP send window in bytes (default=64KB)");
+MODULE_PARM_DESC(cxgb3_snd_win, "TCP send window in bytes (default=128KB)");
 
 static int cxgb3_rx_credit_thres = 10 * 1024;
 module_param(cxgb3_rx_credit_thres, int, 0644);
@@ -301,8 +301,8 @@ static void act_open_req_arp_failure(struct t3cdev *dev, struct sk_buff *skb)
 static void skb_entail(struct s3_conn *c3cn, struct sk_buff *skb,
 		       int flags)
 {
-	CXGB3_SKB_CB(skb)->seq = c3cn->write_seq;
-	CXGB3_SKB_CB(skb)->flags = flags;
+	skb_tcp_seq(skb) = c3cn->write_seq;
+	skb_flags(skb) = flags;
 	__skb_queue_tail(&c3cn->write_queue, skb);
 }
 
@@ -457,12 +457,9 @@ static unsigned int wrlen __read_mostly;
  * The number of WRs needed for an skb depends on the number of fragments
  * in the skb and whether it has any payload in its main body.  This maps the
  * length of the gather list represented by an skb into the # of necessary WRs.
- *
- * The max. length of an skb is controlled by the max pdu size which is ~16K.
- * Also, assume the min. fragment length is the sector size (512), then add
- * extra fragment counts for iscsi bhs and payload padding.
+ * The extra two fragments are for iscsi bhs and payload padding.
  */
-#define SKB_WR_LIST_SIZE	(16384/512 + 3)
+#define SKB_WR_LIST_SIZE	(MAX_SKB_FRAGS + 2)
 static unsigned int skb_wrs[SKB_WR_LIST_SIZE] __read_mostly;
 
 static void s3_init_wr_tab(unsigned int wr_len)
@@ -485,7 +482,7 @@ static void s3_init_wr_tab(unsigned int wr_len)
 
 static inline void reset_wr_list(struct s3_conn *c3cn)
 {
-	c3cn->wr_pending_head = NULL;
+	c3cn->wr_pending_head = c3cn->wr_pending_tail = NULL;
 }
 
 /*
@@ -496,7 +493,7 @@ static inline void reset_wr_list(struct s3_conn *c3cn)
 static inline void enqueue_wr(struct s3_conn *c3cn,
 			      struct sk_buff *skb)
 {
-	skb_wr_data(skb) = NULL;
+	skb_tx_wr_next(skb) = NULL;
 
 	/*
 	 * We want to take an extra reference since both us and the driver
@@ -509,10 +506,22 @@ static inline void enqueue_wr(struct s3_conn *c3cn,
 	if (!c3cn->wr_pending_head)
 		c3cn->wr_pending_head = skb;
 	else
-		skb_wr_data(skb) = skb;
+		skb_tx_wr_next(c3cn->wr_pending_tail) = skb;
 	c3cn->wr_pending_tail = skb;
 }
 
+static int count_pending_wrs(struct s3_conn *c3cn)
+{
+	int n = 0;
+	const struct sk_buff *skb = c3cn->wr_pending_head;
+
+	while (skb) {
+		n += skb->csum;
+		skb = skb_tx_wr_next(skb);
+	}
+	return n;
+}
+
 static inline struct sk_buff *peek_wr(const struct s3_conn *c3cn)
 {
 	return c3cn->wr_pending_head;
@@ -529,8 +538,8 @@ static inline struct sk_buff *dequeue_wr(struct s3_conn *c3cn)
 
 	if (likely(skb)) {
 		/* Don't bother clearing the tail */
-		c3cn->wr_pending_head = skb_wr_data(skb);
-		skb_wr_data(skb) = NULL;
+		c3cn->wr_pending_head = skb_tx_wr_next(skb);
+		skb_tx_wr_next(skb) = NULL;
 	}
 	return skb;
 }
@@ -543,13 +552,14 @@ static void purge_wr_queue(struct s3_conn *c3cn)
 }
 
 static inline void make_tx_data_wr(struct s3_conn *c3cn, struct sk_buff *skb,
-				   int len)
+				   int len, int req_completion)
 {
 	struct tx_data_wr *req;
 
 	skb_reset_transport_header(skb);
 	req = (struct tx_data_wr *)__skb_push(skb, sizeof(*req));
-	req->wr_hi = htonl(V_WR_OP(FW_WROPCODE_OFLD_TX_DATA));
+	req->wr_hi = htonl(V_WR_OP(FW_WROPCODE_OFLD_TX_DATA) |
+			(req_completion ? F_WR_COMPL : 0));
 	req->wr_lo = htonl(V_WR_TID(c3cn->tid));
 	req->sndseq = htonl(c3cn->snd_nxt);
 	/* len includes the length of any HW ULP additions */
@@ -592,7 +602,7 @@ static int c3cn_push_tx_frames(struct s3_conn *c3cn, int req_completion)
 
 	if (unlikely(c3cn->state == C3CN_STATE_CONNECTING ||
 		     c3cn->state == C3CN_STATE_CLOSE_WAIT_1 ||
-		     c3cn->state == C3CN_STATE_ABORTING)) {
+		     c3cn->state >= C3CN_STATE_ABORTING)) {
 		c3cn_tx_debug("c3cn 0x%p, in closing state %u.\n",
 			      c3cn, c3cn->state);
 		return 0;
@@ -615,7 +625,7 @@ static int c3cn_push_tx_frames(struct s3_conn *c3cn, int req_completion)
 		if (c3cn->wr_avail < wrs_needed) {
 			c3cn_tx_debug("c3cn 0x%p, skb len %u/%u, frag %u, "
 				      "wr %d < %u.\n",
-				      c3cn, skb->len, skb->datalen, frags,
+				      c3cn, skb->len, skb->data_len, frags,
 				      wrs_needed, c3cn->wr_avail);
 			break;
 		}
@@ -627,20 +637,24 @@ static int c3cn_push_tx_frames(struct s3_conn *c3cn, int req_completion)
 		c3cn->wr_unacked += wrs_needed;
 		enqueue_wr(c3cn, skb);
 
-		if (likely(CXGB3_SKB_CB(skb)->flags & C3CB_FLAG_NEED_HDR)) {
-			len += ulp_extra_len(skb);
-			make_tx_data_wr(c3cn, skb, len);
-			c3cn->snd_nxt += len;
-			if ((req_completion
-			     && c3cn->wr_unacked == wrs_needed)
-			    || (CXGB3_SKB_CB(skb)->flags & C3CB_FLAG_COMPL)
-			    || c3cn->wr_unacked >= c3cn->wr_max / 2) {
-				struct work_request_hdr *wr = cplhdr(skb);
+		c3cn_tx_debug("c3cn 0x%p, enqueue, skb len %u/%u, frag %u, "
+				"wr %d, left %u, unack %u.\n",
+				c3cn, skb->len, skb->data_len, frags,
+				wrs_needed, c3cn->wr_avail, c3cn->wr_unacked);
+
 
-				wr->wr_hi |= htonl(F_WR_COMPL);
+		if (likely(skb_flags(skb) & C3CB_FLAG_NEED_HDR)) {
+			if ((req_completion &&
+				c3cn->wr_unacked == wrs_needed) ||
+			    (skb_flags(skb) & C3CB_FLAG_COMPL) ||
+			    c3cn->wr_unacked >= c3cn->wr_max / 2) {
+				req_completion = 1;
 				c3cn->wr_unacked = 0;
 			}
-			CXGB3_SKB_CB(skb)->flags &= ~C3CB_FLAG_NEED_HDR;
+			len += ulp_extra_len(skb);
+			make_tx_data_wr(c3cn, skb, len, req_completion);
+			c3cn->snd_nxt += len;
+			skb_flags(skb) &= ~C3CB_FLAG_NEED_HDR;
 		}
 
 		total_size += skb->truesize;
@@ -735,8 +749,11 @@ static void process_act_establish(struct s3_conn *c3cn, struct sk_buff *skb)
 	if (unlikely(c3cn_flag(c3cn, C3CN_ACTIVE_CLOSE_NEEDED)))
 		/* upper layer has requested closing */
 		send_abort_req(c3cn);
-	else if (c3cn_push_tx_frames(c3cn, 1))
+	else {
+		if (skb_queue_len(&c3cn->write_queue))
+			c3cn_push_tx_frames(c3cn, 1);
 		cxgb3i_conn_tx_open(c3cn);
+	}
 }
 
 static int do_act_establish(struct t3cdev *cdev, struct sk_buff *skb,
@@ -1082,8 +1099,8 @@ static void process_rx_iscsi_hdr(struct s3_conn *c3cn, struct sk_buff *skb)
 		return;
 	}
 
-	CXGB3_SKB_CB(skb)->seq = ntohl(hdr_cpl->seq);
-	CXGB3_SKB_CB(skb)->flags = 0;
+	skb_tcp_seq(skb) = ntohl(hdr_cpl->seq);
+	skb_flags(skb) = 0;
 
 	skb_reset_transport_header(skb);
 	__skb_pull(skb, sizeof(struct cpl_iscsi_hdr));
@@ -1103,12 +1120,12 @@ static void process_rx_iscsi_hdr(struct s3_conn *c3cn, struct sk_buff *skb)
 		goto abort_conn;
 
 	skb_ulp_mode(skb) = ULP2_FLAG_DATA_READY;
-	skb_ulp_pdulen(skb) = ntohs(ddp_cpl.len);
-	skb_ulp_ddigest(skb) = ntohl(ddp_cpl.ulp_crc);
+	skb_rx_pdulen(skb) = ntohs(ddp_cpl.len);
+	skb_rx_ddigest(skb) = ntohl(ddp_cpl.ulp_crc);
 	status = ntohl(ddp_cpl.ddp_status);
 
 	c3cn_rx_debug("rx skb 0x%p, len %u, pdulen %u, ddp status 0x%x.\n",
-		      skb, skb->len, skb_ulp_pdulen(skb), status);
+		      skb, skb->len, skb_rx_pdulen(skb), status);
 
 	if (status & (1 << RX_DDP_STATUS_HCRC_SHIFT))
 		skb_ulp_mode(skb) |= ULP2_FLAG_HCRC_ERROR;
@@ -1126,7 +1143,7 @@ static void process_rx_iscsi_hdr(struct s3_conn *c3cn, struct sk_buff *skb)
 	} else if (status & (1 << RX_DDP_STATUS_DDP_SHIFT))
 		skb_ulp_mode(skb) |= ULP2_FLAG_DATA_DDPED;
 
-	c3cn->rcv_nxt = ntohl(ddp_cpl.seq) + skb_ulp_pdulen(skb);
+	c3cn->rcv_nxt = ntohl(ddp_cpl.seq) + skb_rx_pdulen(skb);
 	__pskb_trim(skb, len);
 	__skb_queue_tail(&c3cn->receive_queue, skb);
 	cxgb3i_conn_pdu_ready(c3cn);
@@ -1151,12 +1168,27 @@ static int do_iscsi_hdr(struct t3cdev *t3dev, struct sk_buff *skb, void *ctx)
  * Process an acknowledgment of WR completion.  Advance snd_una and send the
  * next batch of work requests from the write queue.
  */
+static void check_wr_invariants(struct s3_conn *c3cn)
+{
+	int pending = count_pending_wrs(c3cn);
+
+	if (unlikely(c3cn->wr_avail + pending != c3cn->wr_max))
+		cxgb3i_log_error("TID %u: credit imbalance: avail %u, "
+				"pending %u, total should be %u\n",
+				c3cn->tid, c3cn->wr_avail, pending,
+				c3cn->wr_max);
+}
+
 static void process_wr_ack(struct s3_conn *c3cn, struct sk_buff *skb)
 {
 	struct cpl_wr_ack *hdr = cplhdr(skb);
 	unsigned int credits = ntohs(hdr->credits);
 	u32 snd_una = ntohl(hdr->snd_una);
 
+	c3cn_tx_debug("%u WR credits, avail %u, unack %u, TID %u, state %u.\n",
+			credits, c3cn->wr_avail, c3cn->wr_unacked,
+			c3cn->tid, c3cn->state);
+
 	c3cn->wr_avail += credits;
 	if (c3cn->wr_unacked > c3cn->wr_max - c3cn->wr_avail)
 		c3cn->wr_unacked = c3cn->wr_max - c3cn->wr_avail;
@@ -1171,6 +1203,17 @@ static void process_wr_ack(struct s3_conn *c3cn, struct sk_buff *skb)
 			break;
 		}
 		if (unlikely(credits < p->csum)) {
+			struct tx_data_wr *w = cplhdr(p);
+			cxgb3i_log_error("TID %u got %u WR credits need %u, "
+					 "len %u, main body %u, frags %u, "
+					 "seq # %u, ACK una %u, ACK nxt %u, "
+					 "WR_AVAIL %u, WRs pending %u\n",
+					 c3cn->tid, credits, p->csum, p->len,
+					 p->len - p->data_len,
+					 skb_shinfo(p)->nr_frags,
+					 ntohl(w->sndseq), snd_una,
+					 ntohl(hdr->snd_nxt), c3cn->wr_avail,
+					 count_pending_wrs(c3cn) - credits);
 			p->csum -= credits;
 			break;
 		} else {
@@ -1180,15 +1223,24 @@ static void process_wr_ack(struct s3_conn *c3cn, struct sk_buff *skb)
 		}
 	}
 
-	if (unlikely(before(snd_una, c3cn->snd_una)))
+	check_wr_invariants(c3cn);
+
+	if (unlikely(before(snd_una, c3cn->snd_una))) {
+		cxgb3i_log_error("TID %u, unexpected sequence # %u in WR_ACK "
+				 "snd_una %u\n",
+				 c3cn->tid, snd_una, c3cn->snd_una);
 		goto out_free;
+	}
 
 	if (c3cn->snd_una != snd_una) {
 		c3cn->snd_una = snd_una;
 		dst_confirm(c3cn->dst_cache);
 	}
 
-	if (skb_queue_len(&c3cn->write_queue) && c3cn_push_tx_frames(c3cn, 0))
+	if (skb_queue_len(&c3cn->write_queue)) {
+		if (c3cn_push_tx_frames(c3cn, 0))
+			cxgb3i_conn_tx_open(c3cn);
+	} else
 		cxgb3i_conn_tx_open(c3cn);
 out_free:
 	__kfree_skb(skb);
@@ -1452,7 +1504,7 @@ static void init_offload_conn(struct s3_conn *c3cn,
 			      struct dst_entry *dst)
 {
 	BUG_ON(c3cn->cdev != cdev);
-	c3cn->wr_max = c3cn->wr_avail = T3C_DATA(cdev)->max_wrs;
+	c3cn->wr_max = c3cn->wr_avail = T3C_DATA(cdev)->max_wrs - 1;
 	c3cn->wr_unacked = 0;
 	c3cn->mss_idx = select_mss(c3cn, dst_mtu(dst));
 
@@ -1671,9 +1723,17 @@ int cxgb3i_c3cn_send_pdus(struct s3_conn *c3cn, struct sk_buff *skb)
 		goto out_err;
 	}
 
-	err = -EPIPE;
 	if (c3cn->err) {
 		c3cn_tx_debug("c3cn 0x%p, err %d.\n", c3cn, c3cn->err);
+		err = -EPIPE;
+		goto out_err;
+	}
+
+	if (c3cn->write_seq - c3cn->snd_una >= cxgb3_snd_win) {
+		c3cn_tx_debug("c3cn 0x%p, snd %u - %u > %u.\n",
+				c3cn, c3cn->write_seq, c3cn->snd_una,
+				cxgb3_snd_win);
+		err = -EAGAIN;
 		goto out_err;
 	}
 
diff --git a/drivers/scsi/cxgb3i/cxgb3i_offload.h b/drivers/scsi/cxgb3i/cxgb3i_offload.h
index d23156907ff..6344b9eb258 100644
--- a/drivers/scsi/cxgb3i/cxgb3i_offload.h
+++ b/drivers/scsi/cxgb3i/cxgb3i_offload.h
@@ -178,25 +178,33 @@ void cxgb3i_c3cn_release(struct s3_conn *);
  * @flag:	see C3CB_FLAG_* below
  * @ulp_mode:	ULP mode/submode of sk_buff
  * @seq:	tcp sequence number
- * @ddigest:	pdu data digest
- * @pdulen:	recovered pdu length
- * @wr_data:	scratch area for tx wr
  */
+struct cxgb3_skb_rx_cb {
+	__u32 ddigest;			/* data digest */
+	__u32 pdulen;			/* recovered pdu length */
+};
+
+struct cxgb3_skb_tx_cb {
+	struct sk_buff *wr_next;	/* next wr */
+};
+
 struct cxgb3_skb_cb {
 	__u8 flags;
 	__u8 ulp_mode;
 	__u32 seq;
-	__u32 ddigest;
-	__u32 pdulen;
-	struct sk_buff *wr_data;
+	union {
+		struct cxgb3_skb_rx_cb rx;
+		struct cxgb3_skb_tx_cb tx;
+	};
 };
 
 #define CXGB3_SKB_CB(skb)	((struct cxgb3_skb_cb *)&((skb)->cb[0]))
-
+#define skb_flags(skb)		(CXGB3_SKB_CB(skb)->flags)
 #define skb_ulp_mode(skb)	(CXGB3_SKB_CB(skb)->ulp_mode)
-#define skb_ulp_ddigest(skb)	(CXGB3_SKB_CB(skb)->ddigest)
-#define skb_ulp_pdulen(skb)	(CXGB3_SKB_CB(skb)->pdulen)
-#define skb_wr_data(skb)	(CXGB3_SKB_CB(skb)->wr_data)
+#define skb_tcp_seq(skb)	(CXGB3_SKB_CB(skb)->seq)
+#define skb_rx_ddigest(skb)	(CXGB3_SKB_CB(skb)->rx.ddigest)
+#define skb_rx_pdulen(skb)	(CXGB3_SKB_CB(skb)->rx.pdulen)
+#define skb_tx_wr_next(skb)	(CXGB3_SKB_CB(skb)->tx.wr_next)
 
 enum c3cb_flags {
 	C3CB_FLAG_NEED_HDR = 1 << 0,	/* packet needs a TX_DATA_WR header */
@@ -217,6 +225,7 @@ struct sge_opaque_hdr {
 /* for TX: a skb must have a headroom of at least TX_HEADER_LEN bytes */
 #define TX_HEADER_LEN \
 		(sizeof(struct tx_data_wr) + sizeof(struct sge_opaque_hdr))
+#define SKB_TX_HEADROOM		SKB_MAX_HEAD(TX_HEADER_LEN)
 
 /*
  * get and set private ip for iscsi traffic
diff --git a/drivers/scsi/cxgb3i/cxgb3i_pdu.c b/drivers/scsi/cxgb3i/cxgb3i_pdu.c
index ce7ce8c6094..17115c230d6 100644
--- a/drivers/scsi/cxgb3i/cxgb3i_pdu.c
+++ b/drivers/scsi/cxgb3i/cxgb3i_pdu.c
@@ -32,6 +32,10 @@
 #define cxgb3i_tx_debug(fmt...)
 #endif
 
+/* always allocate rooms for AHS */
+#define SKB_TX_PDU_HEADER_LEN	\
+	(sizeof(struct iscsi_hdr) + ISCSI_MAX_AHS_SIZE)
+static unsigned int skb_extra_headroom;
 static struct page *pad_page;
 
 /*
@@ -146,12 +150,13 @@ static inline void tx_skb_setmode(struct sk_buff *skb, int hcrc, int dcrc)
 
 void cxgb3i_conn_cleanup_task(struct iscsi_task *task)
 {
-	struct iscsi_tcp_task *tcp_task = task->dd_data;
+	struct cxgb3i_task_data *tdata = task->dd_data +
+					sizeof(struct iscsi_tcp_task);
 
 	/* never reached the xmit task callout */
-	if (tcp_task->dd_data)
-		kfree_skb(tcp_task->dd_data);
-	tcp_task->dd_data = NULL;
+	if (tdata->skb)
+		__kfree_skb(tdata->skb);
+	memset(tdata, 0, sizeof(struct cxgb3i_task_data));
 
 	/* MNC - Do we need a check in case this is called but
 	 * cxgb3i_conn_alloc_pdu has never been called on the task */
@@ -159,28 +164,102 @@ void cxgb3i_conn_cleanup_task(struct iscsi_task *task)
 	iscsi_tcp_cleanup_task(task);
 }
 
-/*
- * We do not support ahs yet
- */
+static int sgl_seek_offset(struct scatterlist *sgl, unsigned int sgcnt,
+				unsigned int offset, unsigned int *off,
+				struct scatterlist **sgp)
+{
+	int i;
+	struct scatterlist *sg;
+
+	for_each_sg(sgl, sg, sgcnt, i) {
+		if (offset < sg->length) {
+			*off = offset;
+			*sgp = sg;
+			return 0;
+		}
+		offset -= sg->length;
+	}
+	return -EFAULT;
+}
+
+static int sgl_read_to_frags(struct scatterlist *sg, unsigned int sgoffset,
+				unsigned int dlen, skb_frag_t *frags,
+				int frag_max)
+{
+	unsigned int datalen = dlen;
+	unsigned int sglen = sg->length - sgoffset;
+	struct page *page = sg_page(sg);
+	int i;
+
+	i = 0;
+	do {
+		unsigned int copy;
+
+		if (!sglen) {
+			sg = sg_next(sg);
+			if (!sg) {
+				cxgb3i_log_error("%s, sg NULL, len %u/%u.\n",
+						 __func__, datalen, dlen);
+				return -EINVAL;
+			}
+			sgoffset = 0;
+			sglen = sg->length;
+			page = sg_page(sg);
+
+		}
+		copy = min(datalen, sglen);
+		if (i && page == frags[i - 1].page &&
+		    sgoffset + sg->offset ==
+			frags[i - 1].page_offset + frags[i - 1].size) {
+			frags[i - 1].size += copy;
+		} else {
+			if (i >= frag_max) {
+				cxgb3i_log_error("%s, too many pages %u, "
+						 "dlen %u.\n", __func__,
+						 frag_max, dlen);
+				return -EINVAL;
+			}
+
+			frags[i].page = page;
+			frags[i].page_offset = sg->offset + sgoffset;
+			frags[i].size = copy;
+			i++;
+		}
+		datalen -= copy;
+		sgoffset += copy;
+		sglen -= copy;
+	} while (datalen);
+
+	return i;
+}
+
 int cxgb3i_conn_alloc_pdu(struct iscsi_task *task, u8 opcode)
 {
+	struct iscsi_conn *conn = task->conn;
 	struct iscsi_tcp_task *tcp_task = task->dd_data;
-	struct sk_buff *skb;
+	struct cxgb3i_task_data *tdata = task->dd_data + sizeof(*tcp_task);
+	struct scsi_cmnd *sc = task->sc;
+	int headroom = SKB_TX_PDU_HEADER_LEN;
 
+	tcp_task->dd_data = tdata;
 	task->hdr = NULL;
-	/* always allocate rooms for AHS */
-	skb = alloc_skb(sizeof(struct iscsi_hdr) + ISCSI_MAX_AHS_SIZE +
-			TX_HEADER_LEN,  GFP_ATOMIC);
-	if (!skb)
+
+	/* write command, need to send data pdus */
+	if (skb_extra_headroom && (opcode == ISCSI_OP_SCSI_DATA_OUT ||
+	    (opcode == ISCSI_OP_SCSI_CMD &&
+	    (scsi_bidi_cmnd(sc) || sc->sc_data_direction == DMA_TO_DEVICE))))
+		headroom += min(skb_extra_headroom, conn->max_xmit_dlength);
+
+	tdata->skb = alloc_skb(TX_HEADER_LEN + headroom, GFP_ATOMIC);
+	if (!tdata->skb)
 		return -ENOMEM;
+	skb_reserve(tdata->skb, TX_HEADER_LEN);
 
 	cxgb3i_tx_debug("task 0x%p, opcode 0x%x, skb 0x%p.\n",
-			task, opcode, skb);
+			task, opcode, tdata->skb);
 
-	tcp_task->dd_data = skb;
-	skb_reserve(skb, TX_HEADER_LEN);
-	task->hdr = (struct iscsi_hdr *)skb->data;
-	task->hdr_max = sizeof(struct iscsi_hdr);
+	task->hdr = (struct iscsi_hdr *)tdata->skb->data;
+	task->hdr_max = SKB_TX_PDU_HEADER_LEN;
 
 	/* data_out uses scsi_cmd's itt */
 	if (opcode != ISCSI_OP_SCSI_DATA_OUT)
@@ -192,13 +271,13 @@ int cxgb3i_conn_alloc_pdu(struct iscsi_task *task, u8 opcode)
 int cxgb3i_conn_init_pdu(struct iscsi_task *task, unsigned int offset,
 			      unsigned int count)
 {
-	struct iscsi_tcp_task *tcp_task = task->dd_data;
-	struct sk_buff *skb = tcp_task->dd_data;
 	struct iscsi_conn *conn = task->conn;
-	struct page *pg;
+	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);
-	skb_frag_t *frag;
+	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);
@@ -209,90 +288,94 @@ int cxgb3i_conn_init_pdu(struct iscsi_task *task, unsigned int offset,
 		return 0;
 
 	if (task->sc) {
-		struct scatterlist *sg;
-		struct scsi_data_buffer *sdb;
-		unsigned int sgoffset = offset;
-		struct page *sgpg;
-		unsigned int sglen;
-
-		sdb = scsi_out(task->sc);
-		sg = sdb->table.sgl;
-
-		for_each_sg(sdb->table.sgl, sg, sdb->table.nents, i) {
-			cxgb3i_tx_debug("sg %d, page 0x%p, len %u offset %u\n",
-					i, sg_page(sg), sg->length, sg->offset);
-
-			if (sgoffset < sg->length)
-				break;
-			sgoffset -= sg->length;
+		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;
 		}
-		sgpg = sg_page(sg);
-		sglen = sg->length - sgoffset;
-
-		do {
-			int j = skb_shinfo(skb)->nr_frags;
-			unsigned int copy;
-
-			if (!sglen) {
-				sg = sg_next(sg);
-				sgpg = sg_page(sg);
-				sgoffset = 0;
-				sglen = sg->length;
-				++i;
+		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);
 			}
-			copy = min(sglen, datalen);
-			if (j && skb_can_coalesce(skb, j, sgpg,
-						  sg->offset + sgoffset)) {
-				skb_shinfo(skb)->frags[j - 1].size += copy;
-			} else {
-				get_page(sgpg);
-				skb_fill_page_desc(skb, j, sgpg,
-						   sg->offset + sgoffset, copy);
+			if (padlen) {
+				memset(dst, 0, padlen);
+				padlen = 0;
 			}
-			sgoffset += copy;
-			sglen -= copy;
-			datalen -= copy;
-		} while (datalen);
+			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);
 
-		while (datalen) {
-			i = skb_shinfo(skb)->nr_frags;
-			frag = &skb_shinfo(skb)->frags[i];
-
-			get_page(pg);
-			frag->page = pg;
-			frag->page_offset = 0;
-			frag->size = min((unsigned int)PAGE_SIZE, datalen);
-
-			skb_shinfo(skb)->nr_frags++;
-			datalen -= frag->size;
-			pg++;
-		}
+		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;
-		frag = &skb_shinfo(skb)->frags[i];
-		frag->page = pad_page;
-		frag->page_offset = 0;
-		frag->size = padlen;
-		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;
 	}
 
-	datalen = count + padlen;
-	skb->data_len += datalen;
-	skb->truesize += datalen;
-	skb->len += datalen;
 	return 0;
 }
 
 int cxgb3i_conn_xmit_pdu(struct iscsi_task *task)
 {
-	struct iscsi_tcp_task *tcp_task = task->dd_data;
-	struct sk_buff *skb = tcp_task->dd_data;
 	struct iscsi_tcp_conn *tcp_conn = task->conn->dd_data;
 	struct cxgb3i_conn *cconn = tcp_conn->dd_data;
+	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;
 	int err;
 
@@ -300,13 +383,14 @@ int cxgb3i_conn_xmit_pdu(struct iscsi_task *task)
 		return 0;
 
 	datalen = skb->data_len;
-	tcp_task->dd_data = NULL;
+	tdata->skb = NULL;
 	err = cxgb3i_c3cn_send_pdus(cconn->cep->c3cn, skb);
-	cxgb3i_tx_debug("task 0x%p, skb 0x%p, len %u/%u, rv %d.\n",
-			task, skb, skb->len, skb->data_len, err);
 	if (err > 0) {
 		int pdulen = err;
 
+	cxgb3i_tx_debug("task 0x%p, skb 0x%p, len %u/%u, rv %d.\n",
+			task, skb, skb->len, skb->data_len, err);
+
 		if (task->conn->hdrdgst_en)
 			pdulen += ISCSI_DIGEST_SIZE;
 		if (datalen && task->conn->datadgst_en)
@@ -325,12 +409,14 @@ int cxgb3i_conn_xmit_pdu(struct iscsi_task *task)
 		return err;
 	}
 	/* reset skb to send when we are called again */
-	tcp_task->dd_data = skb;
+	tdata->skb = skb;
 	return -EAGAIN;
 }
 
 int cxgb3i_pdu_init(void)
 {
+	if (SKB_TX_HEADROOM > (512 * MAX_SKB_FRAGS))
+		skb_extra_headroom = SKB_TX_HEADROOM;
 	pad_page = alloc_page(GFP_KERNEL);
 	if (!pad_page)
 		return -ENOMEM;
@@ -366,7 +452,9 @@ void cxgb3i_conn_pdu_ready(struct s3_conn *c3cn)
 	skb = skb_peek(&c3cn->receive_queue);
 	while (!err && skb) {
 		__skb_unlink(skb, &c3cn->receive_queue);
-		read += skb_ulp_pdulen(skb);
+		read += skb_rx_pdulen(skb);
+		cxgb3i_rx_debug("conn 0x%p, cn 0x%p, rx skb 0x%p, pdulen %u.\n",
+				conn, c3cn, skb, skb_rx_pdulen(skb));
 		err = cxgb3i_conn_read_pdu_skb(conn, skb);
 		__kfree_skb(skb);
 		skb = skb_peek(&c3cn->receive_queue);
@@ -377,6 +465,11 @@ void cxgb3i_conn_pdu_ready(struct s3_conn *c3cn)
 		cxgb3i_c3cn_rx_credits(c3cn, read);
 	}
 	conn->rxdata_octets += read;
+
+	if (err) {
+		cxgb3i_log_info("conn 0x%p rx failed err %d.\n", conn, err);
+		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+	}
 }
 
 void cxgb3i_conn_tx_open(struct s3_conn *c3cn)
diff --git a/drivers/scsi/cxgb3i/cxgb3i_pdu.h b/drivers/scsi/cxgb3i/cxgb3i_pdu.h
index a3f685cc236..0770b23d90d 100644
--- a/drivers/scsi/cxgb3i/cxgb3i_pdu.h
+++ b/drivers/scsi/cxgb3i/cxgb3i_pdu.h
@@ -53,7 +53,7 @@ struct cpl_rx_data_ddp_norss {
 #define ULP2_FLAG_DCRC_ERROR		0x20
 #define ULP2_FLAG_PAD_ERROR		0x40
 
-void cxgb3i_conn_closing(struct s3_conn *);
+void cxgb3i_conn_closing(struct s3_conn *c3cn);
 void cxgb3i_conn_pdu_ready(struct s3_conn *c3cn);
 void cxgb3i_conn_tx_open(struct s3_conn *c3cn);
 #endif