IB/mlx4: Add CM paravirtualization

In CM para-virtualization:

1. Incoming requests are steered to the correct vHCA according to the
   embedded GID.
2. Communication IDs on outgoing requests are replaced by a globally
   unique ID, generated by the PPF, since there is no synchronization
   of ID generation between guests (and so these IDs are not
   guaranteed to be globally unique).  The guest's comm ID is stored,
   and is returned to the response MAD when it arrives.

Signed-off-by: Amir Vadai <amirv@mellanox.co.il>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>

4 files changed, 468 insertions, 2 deletions

diff --git a/drivers/infiniband/hw/mlx4/Makefile b/drivers/infiniband/hw/mlx4/Makefile
index 20d627d1f04..bf0aa901c31 100644
--- a/drivers/infiniband/hw/mlx4/Makefile
+++ b/drivers/infiniband/hw/mlx4/Makefile
@@ -1,3 +1,3 @@
 obj-$(CONFIG_MLX4_INFINIBAND)   += mlx4_ib.o
 
-mlx4_ib-y :=    ah.o cq.o doorbell.o mad.o main.o mr.o qp.o srq.o mcg.o
+mlx4_ib-y :=    ah.o cq.o doorbell.o mad.o main.o mr.o qp.o srq.o mcg.o cm.o
diff --git a/drivers/infiniband/hw/mlx4/cm.c b/drivers/infiniband/hw/mlx4/cm.c
new file mode 100644
index 00000000000..e25e4dafb8a
--- /dev/null
+++ b/drivers/infiniband/hw/mlx4/cm.c
@@ -0,0 +1,437 @@
+/*
+ * Copyright (c) 2012 Mellanox Technologies. 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 <rdma/ib_mad.h>
+
+#include <linux/mlx4/cmd.h>
+#include <linux/rbtree.h>
+#include <linux/idr.h>
+#include <rdma/ib_cm.h>
+
+#include "mlx4_ib.h"
+
+#define CM_CLEANUP_CACHE_TIMEOUT  (5 * HZ)
+
+struct id_map_entry {
+        struct rb_node node;
+
+        u32 sl_cm_id;
+        u32 pv_cm_id;
+        int slave_id;
+        int scheduled_delete;
+        struct mlx4_ib_dev *dev;
+
+        struct list_head list;
+        struct delayed_work timeout;
+};
+
+struct cm_generic_msg {
+        struct ib_mad_hdr hdr;
+
+        __be32 local_comm_id;
+        __be32 remote_comm_id;
+};
+
+struct cm_req_msg {
+        unsigned char unused[0x60];
+        union ib_gid primary_path_sgid;
+};
+
+
+static void set_local_comm_id(struct ib_mad *mad, u32 cm_id)
+{
+        struct cm_generic_msg *msg = (struct cm_generic_msg *)mad;
+        msg->local_comm_id = cpu_to_be32(cm_id);
+}
+
+static u32 get_local_comm_id(struct ib_mad *mad)
+{
+        struct cm_generic_msg *msg = (struct cm_generic_msg *)mad;
+
+        return be32_to_cpu(msg->local_comm_id);
+}
+
+static void set_remote_comm_id(struct ib_mad *mad, u32 cm_id)
+{
+        struct cm_generic_msg *msg = (struct cm_generic_msg *)mad;
+        msg->remote_comm_id = cpu_to_be32(cm_id);
+}
+
+static u32 get_remote_comm_id(struct ib_mad *mad)
+{
+        struct cm_generic_msg *msg = (struct cm_generic_msg *)mad;
+
+        return be32_to_cpu(msg->remote_comm_id);
+}
+
+static union ib_gid gid_from_req_msg(struct ib_device *ibdev, struct ib_mad *mad)
+{
+        struct cm_req_msg *msg = (struct cm_req_msg *)mad;
+
+        return msg->primary_path_sgid;
+}
+
+/* Lock should be taken before called */
+static struct id_map_entry *
+id_map_find_by_sl_id(struct ib_device *ibdev, u32 slave_id, u32 sl_cm_id)
+{
+        struct rb_root *sl_id_map = &to_mdev(ibdev)->sriov.sl_id_map;
+        struct rb_node *node = sl_id_map->rb_node;
+
+        while (node) {
+                struct id_map_entry *id_map_entry =
+                        rb_entry(node, struct id_map_entry, node);
+
+                if (id_map_entry->sl_cm_id > sl_cm_id)
+                        node = node->rb_left;
+                else if (id_map_entry->sl_cm_id < sl_cm_id)
+                        node = node->rb_right;
+                else if (id_map_entry->slave_id > slave_id)
+                        node = node->rb_left;
+                else if (id_map_entry->slave_id < slave_id)
+                        node = node->rb_right;
+                else
+                        return id_map_entry;
+        }
+        return NULL;
+}
+
+static void id_map_ent_timeout(struct work_struct *work)
+{
+        struct delayed_work *delay = to_delayed_work(work);
+        struct id_map_entry *ent = container_of(delay, struct id_map_entry, timeout);
+        struct id_map_entry *db_ent, *found_ent;
+        struct mlx4_ib_dev *dev = ent->dev;
+        struct mlx4_ib_sriov *sriov = &dev->sriov;
+        struct rb_root *sl_id_map = &sriov->sl_id_map;
+        int pv_id = (int) ent->pv_cm_id;
+
+        spin_lock(&sriov->id_map_lock);
+        db_ent = (struct id_map_entry *)idr_find(&sriov->pv_id_table, pv_id);
+        if (!db_ent)
+                goto out;
+        found_ent = id_map_find_by_sl_id(&dev->ib_dev, ent->slave_id, ent->sl_cm_id);
+        if (found_ent && found_ent == ent)
+                rb_erase(&found_ent->node, sl_id_map);
+        idr_remove(&sriov->pv_id_table, pv_id);
+
+out:
+        list_del(&ent->list);
+        spin_unlock(&sriov->id_map_lock);
+        kfree(ent);
+}
+
+static void id_map_find_del(struct ib_device *ibdev, int pv_cm_id)
+{
+        struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;
+        struct rb_root *sl_id_map = &sriov->sl_id_map;
+        struct id_map_entry *ent, *found_ent;
+
+        spin_lock(&sriov->id_map_lock);
+        ent = (struct id_map_entry *)idr_find(&sriov->pv_id_table, pv_cm_id);
+        if (!ent)
+                goto out;
+        found_ent = id_map_find_by_sl_id(ibdev, ent->slave_id, ent->sl_cm_id);
+        if (found_ent && found_ent == ent)
+                rb_erase(&found_ent->node, sl_id_map);
+        idr_remove(&sriov->pv_id_table, pv_cm_id);
+out:
+        spin_unlock(&sriov->id_map_lock);
+}
+
+static void sl_id_map_add(struct ib_device *ibdev, struct id_map_entry *new)
+{
+        struct rb_root *sl_id_map = &to_mdev(ibdev)->sriov.sl_id_map;
+        struct rb_node **link = &sl_id_map->rb_node, *parent = NULL;
+        struct id_map_entry *ent;
+        int slave_id = new->slave_id;
+        int sl_cm_id = new->sl_cm_id;
+
+        ent = id_map_find_by_sl_id(ibdev, slave_id, sl_cm_id);
+        if (ent) {
+                pr_debug("overriding existing sl_id_map entry (cm_id = %x)\n",
+                         sl_cm_id);
+
+                rb_replace_node(&ent->node, &new->node, sl_id_map);
+                return;
+        }
+
+        /* Go to the bottom of the tree */
+        while (*link) {
+                parent = *link;
+                ent = rb_entry(parent, struct id_map_entry, node);
+
+                if (ent->sl_cm_id > sl_cm_id || (ent->sl_cm_id == sl_cm_id && ent->slave_id > slave_id))
+                        link = &(*link)->rb_left;
+                else
+                        link = &(*link)->rb_right;