[PATCH v2 1/6 2.6.29-rc] cxgb3i - transmit work-request fixes
From: Karen Xie <kxie@xxxxxxxxxxx>
- resize the work-request credit array to be based on skb's MAX_SKB_FRAGS.
- split the skb cb into tx and rx portion
- increase the default transmit window to 128K.
- stop queueing up the outgoing pdus if transmit window is full.
Signed-off-by: Karen Xie <kxie@xxxxxxxxxxx>
---
drivers/scsi/cxgb3i/cxgb3i_offload.c | 146 ++++++++++++++++++++++++----------
drivers/scsi/cxgb3i/cxgb3i_offload.h | 28 ++++---
2 files changed, 121 insertions(+), 53 deletions(-)
diff --git a/drivers/scsi/cxgb3i/cxgb3i_offload.c b/drivers/scsi/cxgb3i/cxgb3i_offload.c
index a865f1f..de3b3b6 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 d231569..df1eae0 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 */
--
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