IB/mlx5: Add GSI QP wrapper

mlx5 creates special GSI QPs that has limited ability to control the P_Key
of transmitted packets. The sent P_Key is taken from the QP object,
similarly to what happens with regular UD QPs.

Create a software wrapper around GSI QPs that with the following patches
will be able to emulate the functionality of a GSI QP including control of
the P_Key per work request.

Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx5/Makefile

@@ -1,4 +1,4 @@
 obj-$(CONFIG_MLX5_INFINIBAND)	+= mlx5_ib.o
 
-mlx5_ib-y :=	main.o cq.o doorbell.o qp.o mem.o srq.o mr.o ah.o mad.o
+mlx5_ib-y :=	main.o cq.o doorbell.o qp.o mem.o srq.o mr.o ah.o mad.o gsi.o
 mlx5_ib-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += odp.o

drivers/infiniband/hw/mlx5/gsi.c

@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) 2016, 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 "mlx5_ib.h"
+
+struct mlx5_ib_gsi_qp {
+	struct ib_qp ibqp;
+	struct ib_qp *rx_qp;
+	u8 port_num;
+	struct ib_qp_cap cap;
+	enum ib_sig_type sq_sig_type;
+	/* Serialize qp state modifications */
+	struct mutex mutex;
+};
+
+static struct mlx5_ib_gsi_qp *gsi_qp(struct ib_qp *qp)
+{
+	return container_of(qp, struct mlx5_ib_gsi_qp, ibqp);
+}
+
+struct ib_qp *mlx5_ib_gsi_create_qp(struct ib_pd *pd,
+				    struct ib_qp_init_attr *init_attr)
+{
+	struct mlx5_ib_dev *dev = to_mdev(pd->device);
+	struct mlx5_ib_gsi_qp *gsi;
+	struct ib_qp_init_attr hw_init_attr = *init_attr;
+	const u8 port_num = init_attr->port_num;
+	int ret;
+
+	mlx5_ib_dbg(dev, "creating GSI QP\n");
+
+	if (port_num > ARRAY_SIZE(dev->devr.ports) || port_num < 1) {
+		mlx5_ib_warn(dev,
+			     "invalid port number %d during GSI QP creation\n",
+			     port_num);
+		return ERR_PTR(-EINVAL);
+	}
+
+	gsi = kzalloc(sizeof(*gsi), GFP_KERNEL);
+	if (!gsi)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_init(&gsi->mutex);
+
+	mutex_lock(&dev->devr.mutex);
+
+	if (dev->devr.ports[port_num - 1].gsi) {
+		mlx5_ib_warn(dev, "GSI QP already exists on port %d\n",
+			     port_num);
+		ret = -EBUSY;
+		goto err_free;
+	}
+
+	gsi->cap = init_attr->cap;
+	gsi->sq_sig_type = init_attr->sq_sig_type;
+	gsi->ibqp.qp_num = 1;
+	gsi->port_num = port_num;
+
+	hw_init_attr.qp_type = MLX5_IB_QPT_HW_GSI;
+	gsi->rx_qp = ib_create_qp(pd, &hw_init_attr);
+	if (IS_ERR(gsi->rx_qp)) {
+		mlx5_ib_warn(dev, "unable to create hardware GSI QP. error %ld\n",
+			     PTR_ERR(gsi->rx_qp));
+		ret = PTR_ERR(gsi->rx_qp);
+		goto err_free;
+	}
+
+	dev->devr.ports[init_attr->port_num - 1].gsi = gsi;
+
+	mutex_unlock(&dev->devr.mutex);
+
+	return &gsi->ibqp;
+
+err_free:
+	mutex_unlock(&dev->devr.mutex);
+	kfree(gsi);
+	return ERR_PTR(ret);
+}
+
+int mlx5_ib_gsi_destroy_qp(struct ib_qp *qp)
+{
+	struct mlx5_ib_dev *dev = to_mdev(qp->device);
+	struct mlx5_ib_gsi_qp *gsi = gsi_qp(qp);
+	const int port_num = gsi->port_num;
+	int ret;
+
+	mlx5_ib_dbg(dev, "destroying GSI QP\n");
+
+	mutex_lock(&dev->devr.mutex);
+	ret = ib_destroy_qp(gsi->rx_qp);
+	if (ret) {
+		mlx5_ib_warn(dev, "unable to destroy hardware GSI QP. error %d\n",
+			     ret);
+		mutex_unlock(&dev->devr.mutex);
+		return ret;
+	}
+	dev->devr.ports[port_num - 1].gsi = NULL;
+	mutex_unlock(&dev->devr.mutex);
+
+	kfree(gsi);
+
+	return 0;
+}
+
+int mlx5_ib_gsi_modify_qp(struct ib_qp *qp, struct ib_qp_attr *attr,
+			  int attr_mask)
+{
+	struct mlx5_ib_dev *dev = to_mdev(qp->device);
+	struct mlx5_ib_gsi_qp *gsi = gsi_qp(qp);
+	int ret;
+
+	mlx5_ib_dbg(dev, "modifying GSI QP to state %d\n", attr->qp_state);
+
+	mutex_lock(&gsi->mutex);
+	ret = ib_modify_qp(gsi->rx_qp, attr, attr_mask);
+	mutex_unlock(&gsi->mutex);
+
+	return ret;
+}
+
+int mlx5_ib_gsi_query_qp(struct ib_qp *qp, struct ib_qp_attr *qp_attr,
+			 int qp_attr_mask,
+			 struct ib_qp_init_attr *qp_init_attr)
+{
+	struct mlx5_ib_gsi_qp *gsi = gsi_qp(qp);
+	int ret;
+
+	mutex_lock(&gsi->mutex);
+	ret = ib_query_qp(gsi->rx_qp, qp_attr, qp_attr_mask, qp_init_attr);
+	qp_init_attr->cap = gsi->cap;
+	mutex_unlock(&gsi->mutex);
+
+	return ret;
+}
+
+int mlx5_ib_gsi_post_send(struct ib_qp *qp, struct ib_send_wr *wr,
+			  struct ib_send_wr **bad_wr)
+{
+	struct mlx5_ib_gsi_qp *gsi = gsi_qp(qp);
+
+	return ib_post_send(gsi->rx_qp, wr, bad_wr);
+}
+
+int mlx5_ib_gsi_post_recv(struct ib_qp *qp, struct ib_recv_wr *wr,
+			  struct ib_recv_wr **bad_wr)
+{
+	struct mlx5_ib_gsi_qp *gsi = gsi_qp(qp);
+
+	return ib_post_recv(gsi->rx_qp, wr, bad_wr);
+}

drivers/infiniband/hw/mlx5/main.c

@@ -1970,6 +1970,8 @@ static int create_dev_resources(struct mlx5_ib_resources *devr)
 
 	dev = container_of(devr, struct mlx5_ib_dev, devr);
 
+	mutex_init(&devr->mutex);
+
 	devr->p0 = mlx5_ib_alloc_pd(&dev->ib_dev, NULL, NULL);
 	if (IS_ERR(devr->p0)) {
 		ret = PTR_ERR(devr->p0);

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -163,6 +163,11 @@ struct mlx5_ib_flow_db {
 #define MLX5_IB_SEND_UMR_FAIL_IF_FREE (IB_SEND_RESERVED_START << 1)
 #define MLX5_IB_SEND_UMR_UPDATE_MTT (IB_SEND_RESERVED_START << 2)
 #define MLX5_IB_QPT_REG_UMR	IB_QPT_RESERVED1
+/*
+ * IB_QPT_GSI creates the software wrapper around GSI, and MLX5_IB_QPT_HW_GSI
+ * creates the actual hardware QP.
+ */
+#define MLX5_IB_QPT_HW_GSI	IB_QPT_RESERVED2
 #define MLX5_IB_WR_UMR		IB_WR_RESERVED1
 
 /* Private QP creation flags to be passed in ib_qp_init_attr.create_flags.
@@ -502,13 +507,22 @@ struct mlx5_mr_cache {
 	unsigned long		last_add;
 };
 
+struct mlx5_ib_gsi_qp;
+
+struct mlx5_ib_port_resources {
+	struct mlx5_ib_gsi_qp *gsi;
+};
+
 struct mlx5_ib_resources {
 	struct ib_cq	*c0;
 	struct ib_xrcd	*x0;
 	struct ib_xrcd	*x1;
 	struct ib_pd	*p0;
 	struct ib_srq	*s0;
 	struct ib_srq	*s1;
+	struct mlx5_ib_port_resources ports[2];
+	/* Protects changes to the port resources */
+	struct mutex	mutex;
 };
 
 struct mlx5_roce {
@@ -754,6 +768,20 @@ static inline void mlx5_ib_qp_enable_pagefaults(struct mlx5_ib_qp *qp)  {}
 __be16 mlx5_get_roce_udp_sport(struct mlx5_ib_dev *dev, u8 port_num,
 			       int index);
 
+/* GSI QP helper functions */
+struct ib_qp *mlx5_ib_gsi_create_qp(struct ib_pd *pd,
+				    struct ib_qp_init_attr *init_attr);
+int mlx5_ib_gsi_destroy_qp(struct ib_qp *qp);
+int mlx5_ib_gsi_modify_qp(struct ib_qp *qp, struct ib_qp_attr *attr,
+			  int attr_mask);
+int mlx5_ib_gsi_query_qp(struct ib_qp *qp, struct ib_qp_attr *qp_attr,
+			 int qp_attr_mask,
+			 struct ib_qp_init_attr *qp_init_attr);
+int mlx5_ib_gsi_post_send(struct ib_qp *qp, struct ib_send_wr *wr,
+			  struct ib_send_wr **bad_wr);
+int mlx5_ib_gsi_post_recv(struct ib_qp *qp, struct ib_recv_wr *wr,
+			  struct ib_recv_wr **bad_wr);
+
 static inline void init_query_mad(struct ib_smp *mad)
 {
 	mad->base_version  = 1;
@@ -773,7 +801,7 @@ static inline u8 convert_access(int acc)
 
 static inline int is_qp1(enum ib_qp_type qp_type)
 {
-	return qp_type == IB_QPT_GSI;
+	return qp_type == MLX5_IB_QPT_HW_GSI;
 }
 
 #define MLX5_MAX_UMR_SHIFT 16