RDMA/cxgb4: Fix LE hash collision bug for passive open connection

It establishes passive open connection through firmware work request. Passive
open connection will go through this path as now instead of listening server we
create a server filter which will redirect the incoming SYN packet to the
offload queue. After this driver tries to establish the connection using
firmware work request.

Signed-off-by: Vipul Pandya <vipul@chelsio.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 79 insertions, 6 deletions

diff --git a/drivers/infiniband/hw/cxgb4/device.c b/drivers/infiniband/hw/cxgb4/device.c
index cb4ecd783700..6b5b3d15e48d 100644
--- a/drivers/infiniband/hw/cxgb4/device.c
+++ b/drivers/infiniband/hw/cxgb4/device.c
@@ -279,6 +279,7 @@ static int stats_show(struct seq_file *seq, void *v)
 	seq_printf(seq, " DB State: %s Transitions %llu\n",
 		   db_state_str[dev->db_state],
 		   dev->rdev.stats.db_state_transitions);
+	seq_printf(seq, "TCAM_FULL: %10llu\n", dev->rdev.stats.tcam_full);
 	return 0;
 }
 
@@ -577,14 +578,76 @@ out:
 	return ctx;
 }
 
+static inline struct sk_buff *copy_gl_to_skb_pkt(const struct pkt_gl *gl,
+						 const __be64 *rsp,
+						 u32 pktshift)
+{
+	struct sk_buff *skb;
+
+	/*
+	 * Allocate space for cpl_pass_accept_req which will be synthesized by
+	 * driver. Once the driver synthesizes the request the skb will go
+	 * through the regular cpl_pass_accept_req processing.
+	 * The math here assumes sizeof cpl_pass_accept_req >= sizeof
+	 * cpl_rx_pkt.
+	 */
+	skb = alloc_skb(gl->tot_len + sizeof(struct cpl_pass_accept_req) +
+			sizeof(struct rss_header) - pktshift, GFP_ATOMIC);
+	if (unlikely(!skb))
+		return NULL;
+
+	 __skb_put(skb, gl->tot_len + sizeof(struct cpl_pass_accept_req) +
+		   sizeof(struct rss_header) - pktshift);
+
+	/*
+	 * This skb will contain:
+	 *   rss_header from the rspq descriptor (1 flit)
+	 *   cpl_rx_pkt struct from the rspq descriptor (2 flits)
+	 *   space for the difference between the size of an
+	 *      rx_pkt and pass_accept_req cpl (1 flit)
+	 *   the packet data from the gl
+	 */
+	skb_copy_to_linear_data(skb, rsp, sizeof(struct cpl_pass_accept_req) +
+				sizeof(struct rss_header));
+	skb_copy_to_linear_data_offset(skb, sizeof(struct rss_header) +
+				       sizeof(struct cpl_pass_accept_req),
+				       gl->va + pktshift,
+				       gl->tot_len - pktshift);
+	return skb;
+}
+
+static inline int recv_rx_pkt(struct c4iw_dev *dev, const struct pkt_gl *gl,
+			   const __be64 *rsp)
+{
+	unsigned int opcode = *(u8 *)rsp;
+	struct sk_buff *skb;
+
+	if (opcode != CPL_RX_PKT)
+		goto out;
+
+	skb = copy_gl_to_skb_pkt(gl , rsp, dev->rdev.lldi.sge_pktshift);
+	if (skb == NULL)
+		goto out;
+
+	if (c4iw_handlers[opcode] == NULL) {
+		pr_info("%s no handler opcode 0x%x...\n", __func__,
+		       opcode);
+		kfree_skb(skb);
+		goto out;
+	}
+	c4iw_handlers[opcode](dev, skb);
+	return 1;
+out:
+	return 0;
+}
+
 static int c4iw_uld_rx_handler(void *handle, const __be64 *rsp,
 			const struct pkt_gl *gl)
 {
 	struct uld_ctx *ctx = handle;
 	struct c4iw_dev *dev = ctx->dev;
 	struct sk_buff *skb;
-	const struct cpl_act_establish *rpl;
-	unsigned int opcode;
+	u8 opcode;
 
 	if (gl == NULL) {
 		/* omit RSS and rsp_ctrl at end of descriptor */
@@ -601,19 +664,29 @@ static int c4iw_uld_rx_handler(void *handle, const __be64 *rsp,
 		u32 qid = be32_to_cpu(rc->pldbuflen_qid);
 		c4iw_ev_handler(dev, qid);
 		return 0;
+	} else if (unlikely(*(u8 *)rsp != *(u8 *)gl->va)) {
+		if (recv_rx_pkt(dev, gl, rsp))
+			return 0;
+
+		pr_info("%s: unexpected FL contents at %p, " \
+		       "RSS %#llx, FL %#llx, len %u\n",
+		       pci_name(ctx->lldi.pdev), gl->va,
+		       (unsigned long long)be64_to_cpu(*rsp),
+		       (unsigned long long)be64_to_cpu(*(u64 *)gl->va),
+		       gl->tot_len);
+
+		return 0;
 	} else {
 		skb = cxgb4_pktgl_to_skb(gl, 128, 128);
 		if (unlikely(!skb))
 			goto nomem;
 	}
 
-	rpl = cplhdr(skb);
-	opcode = rpl->ot.opcode;
-
+	opcode = *(u8 *)rsp;
 	if (c4iw_handlers[opcode])
 		c4iw_handlers[opcode](dev, skb);
 	else
-		printk(KERN_INFO "%s no handler opcode 0x%x...\n", __func__,
+		pr_info("%s no handler opcode 0x%x...\n", __func__,
 		       opcode);
 
 	return 0;