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, 193 insertions, 0 deletions

diff --git a/drivers/infiniband/sw/rxe/rxe_srq.c b/drivers/infiniband/sw/rxe/rxe_srq.c
new file mode 100644
index 000000000000..2a6e3cd2d4e8
--- /dev/null
+++ b/drivers/infiniband/sw/rxe/rxe_srq.c
@@ -0,0 +1,193 @@
+/*
+ * 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 "rxe.h"
+#include "rxe_loc.h"
+#include "rxe_queue.h"
+
+int rxe_srq_chk_attr(struct rxe_dev *rxe, struct rxe_srq *srq,
+		     struct ib_srq_attr *attr, enum ib_srq_attr_mask mask)
+{
+	if (srq && srq->error) {
+		pr_warn("srq in error state\n");
+		goto err1;
+	}
+
+	if (mask & IB_SRQ_MAX_WR) {
+		if (attr->max_wr > rxe->attr.max_srq_wr) {
+			pr_warn("max_wr(%d) > max_srq_wr(%d)\n",
+				attr->max_wr, rxe->attr.max_srq_wr);
+			goto err1;
+		}
+
+		if (attr->max_wr <= 0) {
+			pr_warn("max_wr(%d) <= 0\n", attr->max_wr);
+			goto err1;
+		}
+
+		if (srq && srq->limit && (attr->max_wr < srq->limit)) {
+			pr_warn("max_wr (%d) < srq->limit (%d)\n",
+				attr->max_wr, srq->limit);
+			goto err1;
+		}
+
+		if (attr->max_wr < RXE_MIN_SRQ_WR)
+			attr->max_wr = RXE_MIN_SRQ_WR;
+	}
+
+	if (mask & IB_SRQ_LIMIT) {
+		if (attr->srq_limit > rxe->attr.max_srq_wr) {
+			pr_warn("srq_limit(%d) > max_srq_wr(%d)\n",
+				attr->srq_limit, rxe->attr.max_srq_wr);
+			goto err1;
+		}
+
+		if (srq && (attr->srq_limit > srq->rq.queue->buf->index_mask)) {
+			pr_warn("srq_limit (%d) > cur limit(%d)\n",
+				attr->srq_limit,
+				 srq->rq.queue->buf->index_mask);
+			goto err1;
+		}
+	}
+
+	if (mask == IB_SRQ_INIT_MASK) {
+		if (attr->max_sge > rxe->attr.max_srq_sge) {
+			pr_warn("max_sge(%d) > max_srq_sge(%d)\n",
+				attr->max_sge, rxe->attr.max_srq_sge);
+			goto err1;
+		}
+
+		if (attr->max_sge < RXE_MIN_SRQ_SGE)
+			attr->max_sge = RXE_MIN_SRQ_SGE;
+	}
+
+	return 0;
+
+err1:
+	return -EINVAL;
+}
+
+int rxe_srq_from_init(struct rxe_dev *rxe, struct rxe_srq *srq,
+		      struct ib_srq_init_attr *init,
+		      struct ib_ucontext *context, struct ib_udata *udata)
+{
+	int err;
+	int srq_wqe_size;
+	struct rxe_queue *q;
+
+	srq->ibsrq.event_handler	= init->event_handler;
+	srq->ibsrq.srq_context		= init->srq_context;
+	srq->limit		= init->attr.srq_limit;
+	srq->srq_num		= srq->pelem.index;
+	srq->rq.max_wr		= init->attr.max_wr;
+	srq->rq.max_sge		= init->attr.max_sge;
+
+	srq_wqe_size		= rcv_wqe_size(srq->rq.max_sge);
+
+	spin_lock_init(&srq->rq.producer_lock);
+	spin_lock_init(&srq->rq.consumer_lock);
+
+	q = rxe_queue_init(rxe, &srq->rq.max_wr,
+			   srq_wqe_size);
+	if (!q) {
+		pr_warn("unable to allocate queue for srq\n");
+		return -ENOMEM;
+	}
+
+	srq->rq.queue = q;
+
+	err = do_mmap_info(rxe, udata, false, context, q->buf,
+			   q->buf_size, &q->ip);
+	if (err)
+		return err;
+
+	if (udata && udata->outlen >= sizeof(struct mminfo) + sizeof(u32)) {
+		if (copy_to_user(udata->outbuf + sizeof(struct mminfo),
+				 &srq->srq_num, sizeof(u32)))
+			return -EFAULT;
+	}
+	return 0;
+}
+
+int rxe_srq_from_attr(struct rxe_dev *rxe, struct rxe_srq *srq,
+		      struct ib_srq_attr *attr, enum ib_srq_attr_mask mask,
+		      struct ib_udata *udata)
+{
+	int err;
+	struct rxe_queue *q = srq->rq.queue;
+	struct mminfo mi = { .offset = 1, .size = 0};
+
+	if (mask & IB_SRQ_MAX_WR) {
+		/* Check that we can write the mminfo struct to user space */
+		if (udata && udata->inlen >= sizeof(__u64)) {
+			__u64 mi_addr;
+
+			/* Get address of user space mminfo struct */
+			err = ib_copy_from_udata(&mi_addr, udata,
+						 sizeof(mi_addr));
+			if (err)
+				goto err1;
+
+			udata->outbuf = (void __user *)(unsigned long)mi_addr;
+			udata->outlen = sizeof(mi);
+
+			if (!access_ok(VERIFY_WRITE,
+				       (void __user *)udata->outbuf,
+					udata->outlen)) {
+				err = -EFAULT;
+				goto err1;
+			}
+		}
+
+		err = rxe_queue_resize(q, (unsigned int *)&attr->max_wr,
+				       rcv_wqe_size(srq->rq.max_sge),
+				       srq->rq.queue->ip ?
+						srq->rq.queue->ip->context :
+						NULL,
+				       udata, &srq->rq.producer_lock,
+				       &srq->rq.consumer_lock);
+		if (err)
+			goto err2;
+	}
+
+	if (mask & IB_SRQ_LIMIT)
+		srq->limit = attr->srq_limit;
+
+	return 0;
+
+err2:
+	rxe_queue_cleanup(q);
+	srq->rq.queue = NULL;
+err1:
+	return err;
+}