Soft RoCE driver

Soft RoCE (RXE) - The software RoCE driver

ib_rxe implements the RDMA transport and registers to the RDMA core
device as a kernel verbs provider. It also implements the packet IO
layer. On the other hand ib_rxe registers to the Linux netdev stack
as a udp encapsulating protocol, in that case RDMA, for sending and
receiving packets over any Ethernet device.  This yields a RDMA
transport over the UDP/Ethernet network layer forming a RoCEv2
compatible device.

The configuration procedure of the Soft RoCE drivers requires
binding to any existing Ethernet network device. This is done with
/sys interface.

A userspace Soft RoCE library (librxe) provides user applications
the ability to run with Soft RoCE devices.  The use of rxe verbs ins
user space requires the inclusion of librxe as a device specifics
plug-in to libibverbs. librxe is packaged separately.

Architecture:

     +-----------------------------------------------------------+
     |                          Application                      |
     +-----------------------------------------------------------+
                            +-----------------------------------+
                            |             libibverbs            |
User                        +-----------------------------------+
                            +----------------+ +----------------+
                            | librxe         | | HW RoCE lib    |
                            +----------------+ +----------------+
+---------------------------------------------------------------+
     +--------------+                           +------------+
     | Sockets      |                           | RDMA ULP   |
     +--------------+                           +------------+
     +--------------+                  +---------------------+
     | TCP/IP       |                  | ib_core             |
     +--------------+                  +---------------------+
                             +------------+ +----------------+
Kernel                       | ib_rxe     | | HW RoCE driver |
                             +------------+ +----------------+
     +------------------------------------+
     | NIC driver                         |
     +------------------------------------+

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     +-----------------------------------------------------------+
     |                          Application                      |
     +-----------------------------------------------------------+
                            +-----------------------------------+
                            |             libibverbs            |
User                        +-----------------------------------+
                            +----------------+ +----------------+
                            | librxe         | | HW RoCE lib    |
                            +----------------+ +----------------+
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     +--------------+                           +------------+
     | Sockets      |                           | RDMA ULP   |
     +--------------+                           +------------+
     +--------------+                  +---------------------+
     | TCP/IP       |                  | ib_core             |
     +--------------+                  +---------------------+
                             +------------+ +----------------+
Kernel                       | ib_rxe     | | HW RoCE driver |
                             +------------+ +----------------+
     +------------------------------------+
     | NIC driver                         |
     +------------------------------------+
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Soft RoCE resources:

[1[ https://github.com/SoftRoCE/librxe-dev librxe - source code in
Github
[2] https://github.com/SoftRoCE/rxe-dev/wiki/rxe-dev:-Home - Soft RoCE
Wiki page
[3] https://github.com/SoftRoCE/librxe-dev - Soft RoCE userspace library

Signed-off-by: Kamal Heib <kamalh@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Reviewed-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 420 insertions, 0 deletions

diff --git a/drivers/infiniband/sw/rxe/rxe_recv.c b/drivers/infiniband/sw/rxe/rxe_recv.c
new file mode 100644
index 000000000000..3d464c23e08b
--- /dev/null
+++ b/drivers/infiniband/sw/rxe/rxe_recv.c
@@ -0,0 +1,420 @@
+/*
+ * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
+ * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *	- Redistributions of source code must retain the above
+ *	  copyright notice, this list of conditions and the following
+ *	  disclaimer.
+ *
+ *	- Redistributions in binary form must reproduce the above
+ *	  copyright notice, this list of conditions and the following
+ *	  disclaimer in the documentation and/or other materials
+ *	  provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/skbuff.h>
+
+#include "rxe.h"
+#include "rxe_loc.h"
+
+static int check_type_state(struct rxe_dev *rxe, struct rxe_pkt_info *pkt,
+			    struct rxe_qp *qp)
+{
+	if (unlikely(!qp->valid))
+		goto err1;
+
+	switch (qp_type(qp)) {
+	case IB_QPT_RC:
+		if (unlikely((pkt->opcode & IB_OPCODE_RC) != 0)) {
+			pr_warn_ratelimited("bad qp type\n");
+			goto err1;
+		}
+		break;
+	case IB_QPT_UC:
+		if (unlikely(!(pkt->opcode & IB_OPCODE_UC))) {
+			pr_warn_ratelimited("bad qp type\n");
+			goto err1;
+		}
+		break;
+	case IB_QPT_UD:
+	case IB_QPT_SMI:
+	case IB_QPT_GSI:
+		if (unlikely(!(pkt->opcode & IB_OPCODE_UD))) {
+			pr_warn_ratelimited("bad qp type\n");
+			goto err1;
+		}
+		break;
+	default:
+		pr_warn_ratelimited("unsupported qp type\n");
+		goto err1;
+	}
+
+	if (pkt->mask & RXE_REQ_MASK) {
+		if (unlikely(qp->resp.state != QP_STATE_READY))
+			goto err1;
+	} else if (unlikely(qp->req.state < QP_STATE_READY ||
+				qp->req.state > QP_STATE_DRAINED)) {
+		goto err1;
+	}
+
+	return 0;
+
+err1:
+	return -EINVAL;
+}
+
+static void set_bad_pkey_cntr(struct rxe_port *port)
+{
+	spin_lock_bh(&port->port_lock);
+	port->attr.bad_pkey_cntr = min((u32)0xffff,
+				       port->attr.bad_pkey_cntr + 1);
+	spin_unlock_bh(&port->port_lock);
+}
+
+static void set_qkey_viol_cntr(struct rxe_port *port)
+{
+	spin_lock_bh(&port->port_lock);
+	port->attr.qkey_viol_cntr = min((u32)0xffff,
+					port->attr.qkey_viol_cntr + 1);
+	spin_unlock_bh(&port->port_lock);
+}
+
+static int check_keys(struct rxe_dev *rxe, struct rxe_pkt_info *pkt,
+		      u32 qpn, struct rxe_qp *qp)
+{
+	int i;
+	int found_pkey = 0;
+	struct rxe_port *port = &rxe->port;
+	u16 pkey = bth_pkey(pkt);
+
+	pkt->pkey_index = 0;
+
+	if (qpn == 1) {
+		for (i = 0; i < port->attr.pkey_tbl_len; i++) {
+			if (pkey_match(pkey, port->pkey_tbl[i])) {
+				pkt->pkey_index = i;
+				found_pkey = 1;
+				break;
+			}
+		}
+
+		if (!found_pkey) {
+			pr_warn_ratelimited("bad pkey = 0x%x\n", pkey);
+			set_bad_pkey_cntr(port);
+			goto err1;
+		}
+	} else if (qpn != 0) {
+		if (unlikely(!pkey_match(pkey,
+					 port->pkey_tbl[qp->attr.pkey_index]
+					))) {
+			pr_warn_ratelimited("bad pkey = 0x%0x\n", pkey);
+			set_bad_pkey_cntr(port);
+			goto err1;
+		}
+		pkt->pkey_index = qp->attr.pkey_index;
+	}
+
+	if ((qp_type(qp) == IB_QPT_UD || qp_type(qp) == IB_QPT_GSI) &&
+	    qpn != 0 && pkt->mask) {
+		u32 qkey = (qpn == 1) ? GSI_QKEY : qp->attr.qkey;
+
+		if (unlikely(deth_qkey(pkt) != qkey)) {
+			pr_warn_ratelimited("bad qkey, got 0x%x expected 0x%x for qpn 0x%x\n",
+					    deth_qkey(pkt), qkey, qpn);
+			set_qkey_viol_cntr(port);
+			goto err1;
+		}
+	}
+
+	return 0;
+
+err1:
+	return -EINVAL;
+}
+
+static int check_addr(struct rxe_dev *rxe, struct rxe_pkt_info *pkt,
+		      struct rxe_qp *qp)
+{
+	struct sk_buff *skb = PKT_TO_SKB(pkt);
+
+	if (qp_type(qp) != IB_QPT_RC && qp_type(qp) != IB_QPT_UC)
+		goto done;
+
+	if (unlikely(pkt->port_num != qp->attr.port_num)) {
+		pr_warn_ratelimited("port %d != qp port %d\n",
+				    pkt->port_num, qp->attr.port_num);
+		goto err1;
+	}
+
+	if (skb->protocol == htons(ETH_P_IP)) {
+		struct in_addr *saddr =
+			&qp->pri_av.sgid_addr._sockaddr_in.sin_addr;
+		struct in_addr *daddr =
+			&qp->pri_av.dgid_addr._sockaddr_in.sin_addr;
+
+		if (ip_hdr(skb)->daddr != saddr->s_addr) {
+			pr_warn_ratelimited("dst addr %pI4 != qp source addr %pI4\n",
+					    &ip_hdr(skb)->daddr,
+					    &saddr->s_addr);
+			goto err1;
+		}
+
+		if (ip_hdr(skb)->saddr != daddr->s_addr) {
+			pr_warn_ratelimited("source addr %pI4 != qp dst addr %pI4\n",
+					    &ip_hdr(skb)->saddr,
+					    &daddr->s_addr);
+			goto err1;
+		}
+
+	} else if (skb->protocol == htons(ETH_P_IPV6)) {
+		struct in6_addr *saddr =
+			&qp->pri_av.sgid_addr._sockaddr_in6.sin6_addr;
+		struct in6_addr *daddr =
+			&qp->pri_av.dgid_addr._sockaddr_in6.sin6_addr;
+
+		if (memcmp(&ipv6_hdr(skb)->daddr, saddr, sizeof(*saddr))) {
+			pr_warn_ratelimited("dst addr %pI6 != qp source addr %pI6\n",
+					    &ipv6_hdr(skb)->daddr, saddr);
+			goto err1;
+		}
+
+		if (memcmp(&ipv6_hdr(skb)->saddr, daddr, sizeof(*daddr))) {
+			pr_warn_ratelimited("source addr %pI6 != qp dst addr %pI6\n",
+					    &ipv6_hdr(skb)->saddr, daddr);
+			goto err1;
+		}
+	}
+
+done:
+	return 0;
+
+err1:
+	return -EINVAL;
+}
+
+static int hdr_check(struct rxe_pkt_info *pkt)
+{
+	struct rxe_dev *rxe = pkt->rxe;
+	struct rxe_port *port = &rxe->port;
+	struct rxe_qp *qp = NULL;
+	u32 qpn = bth_qpn(pkt);
+	int index;
+	int err;
+
+	if (unlikely(bth_tver(pkt) != BTH_TVER)) {
+		pr_warn_ratelimited("bad tver\n");
+		goto err1;
+	}
+
+	if (qpn != IB_MULTICAST_QPN) {
+		index = (qpn == 0) ? port->qp_smi_index :
+			((qpn == 1) ? port->qp_gsi_index : qpn);
+		qp = rxe_pool_get_index(&rxe->qp_pool, index);
+		if (unlikely(!qp)) {
+			pr_warn_ratelimited("no qp matches qpn 0x%x\n", qpn);
+			goto err1;
+		}
+
+		err = check_type_state(rxe, pkt, qp);
+		if (unlikely(err))
+			goto err2;
+
+		err = check_addr(rxe, pkt, qp);
+		if (unlikely(err))
+			goto err2;
+
+		err = check_keys(rxe, pkt, qpn, qp);
+		if (unlikely(err))
+			goto err2;
+	} else {
+		if (unlikely((pkt->mask & RXE_GRH_MASK) == 0)) {
+			pr_warn_ratelimited("no grh for mcast qpn\n");
+			goto err1;
+		}
+	}
+
+	pkt->qp = qp;
+	return 0;
+
+err2:
+	if (qp)
+		rxe_drop_ref(qp);
+err1:
+	return -EINVAL;
+}
+
+static inline void rxe_rcv_pkt(struct rxe_dev *rxe,
+			       struct rxe_pkt_info *pkt,
+			       struct sk_buff *skb)
+{
+	if (pkt->mask & RXE_REQ_MASK)
+		rxe_resp_queue_pkt(rxe, pkt->qp, skb);
+	else
+		rxe_comp_queue_pkt(rxe, pkt->qp, skb);
+}
+
+static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb)
+{
+	struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
+	struct rxe_mc_grp *mcg;
+	struct sk_buff *skb_copy;
+	struct rxe_mc_elem *mce;
+	struct rxe_qp *qp;
+	union ib_gid dgid;
+	int err;
+
+	if (skb->protocol == htons(ETH_P_IP))
+		ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
+				       (struct in6_addr *)&dgid);
+	else if (skb->protocol == htons(ETH_P_IPV6))
+		memcpy(&dgid, &ipv6_hdr(skb)->daddr, sizeof(dgid));
+
+	/* lookup mcast group corresponding to mgid, takes a ref */
+	mcg = rxe_pool_get_key(&rxe->mc_grp_pool, &dgid);
+	if (!mcg)
+		goto err1;	/* mcast group not registered */
+
+	spin_lock_bh(&mcg->mcg_lock);
+
+	list_for_each_entry(mce, &mcg->qp_list, qp_list) {
+		qp = mce->qp;
+		pkt = SKB_TO_PKT(skb);
+
+		/* validate qp for incoming packet */
+		err = check_type_state(rxe, pkt, qp);
+		if (err)
+			continue;
+
+		err = check_keys(rxe, pkt, bth_qpn(pkt), qp);
+		if (err)
+			continue;
+
+		/* if *not* the last qp in the list
+		 * make a copy of the skb to post to the next qp
+		 */
+		skb_copy = (mce->qp_list.next != &mcg->qp_list) ?
+				skb_clone(skb, GFP_KERNEL) : NULL;
+
+		pkt->qp = qp;
+		rxe_add_ref(qp);
+		rxe_rcv_pkt(rxe, pkt, skb);
+
+		skb = skb_copy;
+		if (!skb)
+			break;
+	}
+
+	spin_unlock_bh(&mcg->mcg_lock);
+
+	rxe_drop_ref(mcg);	/* drop ref from rxe_pool_get_key. */
+
+err1:
+	if (skb)
+		kfree_skb(skb);
+}
+
+static int rxe_match_dgid(struct rxe_dev *rxe, struct sk_buff *skb)
+{
+	union ib_gid dgid;
+	union ib_gid *pdgid;
+	u16 index;
+
+	if (skb->protocol == htons(ETH_P_IP)) {
+		ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
+				       (struct in6_addr *)&dgid);
+		pdgid = &dgid;
+	} else {
+		pdgid = (union ib_gid *)&ipv6_hdr(skb)->daddr;
+	}
+
+	return ib_find_cached_gid_by_port(&rxe->ib_dev, pdgid,
+					  IB_GID_TYPE_ROCE_UDP_ENCAP,
+					  1, rxe->ndev, &index);
+}
+
+/* rxe_rcv is called from the interface driver */
+int rxe_rcv(struct sk_buff *skb)
+{
+	int err;
+	struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
+	struct rxe_dev *rxe = pkt->rxe;
+	__be32 *icrcp;
+	u32 calc_icrc, pack_icrc;
+
+	pkt->offset = 0;
+
+	if (unlikely(skb->len < pkt->offset + RXE_BTH_BYTES))
+		goto drop;
+
+	if (unlikely(rxe_match_dgid(rxe, skb) < 0)) {
+		pr_warn_ratelimited("failed matching dgid\n");
+		goto drop;
+	}
+
+	pkt->opcode = bth_opcode(pkt);
+	pkt->psn = bth_psn(pkt);
+	pkt->qp = NULL;
+	pkt->mask |= rxe_opcode[pkt->opcode].mask;
+
+	if (unlikely(skb->len < header_size(pkt)))
+		goto drop;
+
+	err = hdr_check(pkt);
+	if (unlikely(err))
+		goto drop;
+
+	/* Verify ICRC */
+	icrcp = (__be32 *)(pkt->hdr + pkt->paylen - RXE_ICRC_SIZE);
+	pack_icrc = be32_to_cpu(*icrcp);
+
+	calc_icrc = rxe_icrc_hdr(pkt, skb);
+	calc_icrc = crc32_le(calc_icrc, (u8 *)payload_addr(pkt), payload_size(pkt));
+	calc_icrc = cpu_to_be32(~calc_icrc);
+	if (unlikely(calc_icrc != pack_icrc)) {
+		char saddr[sizeof(struct in6_addr)];
+
+		if (skb->protocol == htons(ETH_P_IPV6))
+			sprintf(saddr, "%pI6", &ipv6_hdr(skb)->saddr);
+		else if (skb->protocol == htons(ETH_P_IP))
+			sprintf(saddr, "%pI4", &ip_hdr(skb)->saddr);
+		else
+			sprintf(saddr, "unknown");
+
+		pr_warn_ratelimited("bad ICRC from %s\n", saddr);
+		goto drop;
+	}
+
+	if (unlikely(bth_qpn(pkt) == IB_MULTICAST_QPN))
+		rxe_rcv_mcast_pkt(rxe, skb);
+	else
+		rxe_rcv_pkt(rxe, pkt, skb);
+
+	return 0;
+
+drop:
+	if (pkt->qp)
+		rxe_drop_ref(pkt->qp);
+
+	kfree_skb(skb);
+	return 0;
+}
+EXPORT_SYMBOL(rxe_rcv);