diff mbox

[v2,35/37] add rxe_sample.c

Message ID 20110724201229.865806162@systemfabricworks.com (mailing list archive)
State New, archived
Headers show

Commit Message

Robert Pearson July 24, 2011, 7:43 p.m. UTC
module that implements a soft IB device using ib_rxe in loopback.

Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com>

---
 drivers/infiniband/hw/rxe/rxe_sample.c |  226 +++++++++++++++++++++++++++++++++
 1 file changed, 226 insertions(+)



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Comments

Bart Van Assche Aug. 7, 2011, 8:08 a.m. UTC | #1
On Sun, Jul 24, 2011 at 9:43 PM,  <rpearson@systemfabricworks.com> wrote:
> module that implements a soft IB device using ib_rxe in loopback.
> +MODULE_DESCRIPTION("RDMA transport over Converged Enhanced Ethernet");

That's the same description as for the ib_rxe_net kernel module, so
one of the two probably should be updated.

> +MODULE_LICENSE("Dual BSD/GPL");
> +
> +static __be64 node_guid(struct rxe_dev *rxe)
> +{
> +	return cpu_to_be64(0x3333333333333333ULL);
> +}

In the OUI part of the above EUI-64 identifier the "M" (multicast) and
L ("locally administered") bits are set. I'm not sure that's fine.
Also, has it been considered to use __constant_cpu_to_be64() instead
of cpu_to_be64() ?

> +static __be64 port_guid(struct rxe_dev *rxe, unsigned int port_num)
> +{
> +	return cpu_to_be64(0x4444444444444444ULL);
> +}

Same remark here about __constant_cpu_to_be64().

> +/*
> + * the ofed core requires that we provide a valid device
> + * object for registration
> + */
> +static struct class *my_class;
> +static struct device *my_dev;

Probably the above comment should be updated since this driver is
being submitted for inclusion in the mainline Linux kernel ?

> +	if (av->attr.ah_flags & IB_AH_GRH)
> +		pkt->mask	|= RXE_GRH_MASK;

Please use a space instead of a tab before "|=".

> +static struct rxe_dev *rxe_sample;
> +
> +static int rxe_sample_add(void)
> +{
> +	int err;
> +	struct rxe_port *port;
> +
> +	rxe_sample = (struct rxe_dev *)ib_alloc_device(sizeof(*rxe_sample));
> +	if (!rxe_sample) {
> +		err = -ENOMEM;
> +		goto err1;
> +	}

Since calling rxe_sample_add() twice in a row is an error a check for
that condition might be appropriate, e.g. by inserting a
WARN_ON(rxe_sample) before the allocation.

> +static void rxe_sample_remove(void)
> +{
> +	if (!rxe_sample)
> +		goto done;
> +
> +	rxe_remove(rxe_sample);
> +
> +	pr_info("rxe_sample: removed %s\n",
> +		rxe_sample->ib_dev.name);
> +done:
> +	return;
> +}

Setting rxe_sample to NULL after the rxe_remove() call can be a help
to catch potential dangling pointer dereferences.

> +
> +static int __init rxe_sample_init(void)
> +{
> +	int err;
> +
> +	rxe_crc_disable = 1;
> +
> +	my_class = class_create(THIS_MODULE, "foo");
> +	my_dev = device_create(my_class, NULL, 0, NULL, "bar");
> +
> +	err = rxe_sample_add();
> +	return err;
> +}

Sorry, but it's not clear to me why a new class has to be created this
sample driver. Also, one should be aware that class and device names
are globally visible and hence should be meaningful - names like "foo"
and "bar" are not acceptable.

# find /sys -name foo -o -name bar
/sys/devices/virtual/foo
/sys/devices/virtual/foo/bar
/sys/class/foo
/sys/class/foo/bar

Bart.
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diff mbox

Patch

Index: infiniband/drivers/infiniband/hw/rxe/rxe_sample.c
===================================================================
--- /dev/null
+++ infiniband/drivers/infiniband/hw/rxe/rxe_sample.c
@@ -0,0 +1,226 @@ 
+/*
+ * Copyright (c) 2009-2011 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.
+ */
+
+/*
+ * sample driver for IB transport over rxe
+ * implements a simple loopback device on module load
+ */
+
+#include <linux/skbuff.h>
+
+#include <linux/device.h>
+
+#include "rxe.h"
+
+MODULE_AUTHOR("Bob Pearson");
+MODULE_DESCRIPTION("RDMA transport over Converged Enhanced Ethernet");
+MODULE_LICENSE("Dual BSD/GPL");
+
+static __be64 node_guid(struct rxe_dev *rxe)
+{
+	return cpu_to_be64(0x3333333333333333ULL);
+}
+
+static __be64 port_guid(struct rxe_dev *rxe, unsigned int port_num)
+{
+	return cpu_to_be64(0x4444444444444444ULL);
+}
+
+/*
+ * the ofed core requires that we provide a valid device
+ * object for registration
+ */
+static struct class *my_class;
+static struct device *my_dev;
+
+static struct device *dma_device(struct rxe_dev *rxe)
+{
+	return my_dev;
+}
+
+static int mcast_add(struct rxe_dev *rxe, union ib_gid *mgid)
+{
+	return 0;
+}
+
+static int mcast_delete(struct rxe_dev *rxe, union ib_gid *mgid)
+{
+	return 0;
+}
+
+/* just loopback packet */
+static int send(struct rxe_dev *rxe, struct sk_buff *skb)
+{
+	struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
+
+	pkt->rxe = rxe;
+	pkt->mask = RXE_LRH_MASK;
+
+	return rxe_rcv(skb);
+}
+
+static struct sk_buff *init_packet(struct rxe_dev *rxe, struct rxe_av *av,
+				   int paylen)
+{
+	struct sk_buff *skb;
+	struct rxe_pkt_info *pkt;
+
+	paylen += RXE_LRH_BYTES;
+
+	if (av->attr.ah_flags & IB_AH_GRH)
+		paylen += RXE_GRH_BYTES;
+
+	skb = alloc_skb(paylen, GFP_ATOMIC);
+	if (!skb)
+		return NULL;
+
+	skb->dev	= NULL;
+	skb->protocol	= 0;
+
+	pkt		= SKB_TO_PKT(skb);
+	pkt->rxe	= rxe;
+	pkt->port_num	= 1;
+	pkt->hdr	= skb_put(skb, paylen);
+	pkt->mask	= RXE_LRH_MASK;
+	if (av->attr.ah_flags & IB_AH_GRH)
+		pkt->mask	|= RXE_GRH_MASK;
+
+	return skb;
+}
+
+static int init_av(struct rxe_dev *rxe, struct ib_ah_attr *attr,
+		   struct rxe_av *av)
+{
+	if (!av->attr.dlid)
+		av->attr.dlid = 1;
+	return 0;
+}
+
+static char *parent_name(struct rxe_dev *rxe, unsigned int port_num)
+{
+	return "sample";
+}
+
+static enum rdma_link_layer link_layer(struct rxe_dev *rxe,
+				       unsigned int port_num)
+{
+	return IB_LINK_LAYER_INFINIBAND;
+}
+
+static struct rxe_ifc_ops ifc_ops = {
+	.node_guid	= node_guid,
+	.port_guid	= port_guid,
+	.dma_device	= dma_device,
+	.mcast_add	= mcast_add,
+	.mcast_delete	= mcast_delete,
+	.send		= send,
+	.init_packet	= init_packet,
+	.init_av	= init_av,
+	.parent_name	= parent_name,
+	.link_layer	= link_layer,
+};
+
+static struct rxe_dev *rxe_sample;
+
+static int rxe_sample_add(void)
+{
+	int err;
+	struct rxe_port *port;
+
+	rxe_sample = (struct rxe_dev *)ib_alloc_device(sizeof(*rxe_sample));
+	if (!rxe_sample) {
+		err = -ENOMEM;
+		goto err1;
+	}
+
+	rxe_sample->ifc_ops = &ifc_ops;
+
+	err = rxe_add(rxe_sample, 4500);
+	if (err)
+		goto err2;
+
+	/* bit of a hack */
+	port = &rxe_sample->port[0];
+	port->attr.state = IB_PORT_ACTIVE;
+	port->attr.phys_state = 5;
+	port->attr.max_mtu = IB_MTU_4096;
+	port->attr.active_mtu = IB_MTU_4096;
+	port->mtu_cap = IB_MTU_4096;
+	port->attr.lid = 1;
+
+	pr_info("rxe_sample: added %s\n",
+		 rxe_sample->ib_dev.name);
+	return 0;
+
+err2:
+	ib_dealloc_device(&rxe_sample->ib_dev);
+err1:
+	return err;
+}
+
+static void rxe_sample_remove(void)
+{
+	if (!rxe_sample)
+		goto done;
+
+	rxe_remove(rxe_sample);
+
+	pr_info("rxe_sample: removed %s\n",
+		rxe_sample->ib_dev.name);
+done:
+	return;
+}
+
+static int __init rxe_sample_init(void)
+{
+	int err;
+
+	rxe_crc_disable = 1;
+
+	my_class = class_create(THIS_MODULE, "foo");
+	my_dev = device_create(my_class, NULL, 0, NULL, "bar");
+
+	err = rxe_sample_add();
+	return err;
+}
+
+static void __exit rxe_sample_exit(void)
+{
+	rxe_sample_remove();
+
+	device_destroy(my_class, my_dev->devt);
+	class_destroy(my_class);
+	return;
+}
+
+module_init(rxe_sample_init);
+module_exit(rxe_sample_exit);