diff mbox series

[v7,04/25] RDMA/rtrs: core: lib functions shared between client and server modules

Message ID 20200116125915.14815-5-jinpuwang@gmail.com (mailing list archive)
State New, archived
Headers show
Series RTRS (former IBTRS) RDMA Transport Library and RNBD (former IBNBD) RDMA Network Block Device | expand

Commit Message

Jinpu Wang Jan. 16, 2020, 12:58 p.m. UTC
From: Jack Wang <jinpu.wang@cloud.ionos.com>

This is a set of library functions existing as a rtrs-core module,
used by client and server modules.

Mainly these functions wrap IB and RDMA calls and provide a bit higher
abstraction for implementing of RTRS protocol on client or server
sides.

Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
---
 drivers/infiniband/ulp/rtrs/rtrs.c | 597 +++++++++++++++++++++++++++++
 1 file changed, 597 insertions(+)
 create mode 100644 drivers/infiniband/ulp/rtrs/rtrs.c

Comments

Leon Romanovsky Jan. 19, 2020, 2:48 p.m. UTC | #1
On Thu, Jan 16, 2020 at 01:58:54PM +0100, Jack Wang wrote:
> From: Jack Wang <jinpu.wang@cloud.ionos.com>
>
> This is a set of library functions existing as a rtrs-core module,
> used by client and server modules.
>
> Mainly these functions wrap IB and RDMA calls and provide a bit higher
> abstraction for implementing of RTRS protocol on client or server
> sides.
>
> Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
> Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
> ---
>  drivers/infiniband/ulp/rtrs/rtrs.c | 597 +++++++++++++++++++++++++++++
>  1 file changed, 597 insertions(+)
>  create mode 100644 drivers/infiniband/ulp/rtrs/rtrs.c
>
> diff --git a/drivers/infiniband/ulp/rtrs/rtrs.c b/drivers/infiniband/ulp/rtrs/rtrs.c
> new file mode 100644
> index 000000000000..7b84d76e2a67
> --- /dev/null
> +++ b/drivers/infiniband/ulp/rtrs/rtrs.c
> @@ -0,0 +1,597 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * RDMA Transport Layer
> + *
> + * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
> + *
> + * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
> + *
> + * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
> + */
> +#undef pr_fmt
> +#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
> +
> +#include <linux/module.h>
> +#include <linux/inet.h>
> +
> +#include "rtrs-pri.h"
> +#include "rtrs-log.h"
> +
> +MODULE_DESCRIPTION("RDMA Transport Core");
> +MODULE_LICENSE("GPL");
> +
> +struct rtrs_iu *rtrs_iu_alloc(u32 queue_size, size_t size, gfp_t gfp_mask,
> +			      struct ib_device *dma_dev,
> +			      enum dma_data_direction dir,
> +			      void (*done)(struct ib_cq *cq, struct ib_wc *wc))
> +{
> +	struct rtrs_iu *ius, *iu;
> +	int i;
> +
> +	WARN_ON(!queue_size);
> +	ius = kcalloc(queue_size, sizeof(*ius), gfp_mask);
> +	if (unlikely(!ius))
> +		return NULL;

Let's do not add useless WARN_ON() and unlikely to every error path.

> +	for (i = 0; i < queue_size; i++) {
> +		iu = &ius[i];
> +		iu->buf = kzalloc(size, gfp_mask);
> +		if (unlikely(!iu->buf))
> +			goto err;
> +
> +		iu->dma_addr = ib_dma_map_single(dma_dev, iu->buf, size, dir);
> +		if (unlikely(ib_dma_mapping_error(dma_dev, iu->dma_addr)))
> +			goto err;
> +
> +		iu->cqe.done  = done;
> +		iu->size      = size;
> +		iu->direction = dir;
> +	}
> +	return ius;
> +err:
> +	rtrs_iu_free(ius, dir, dma_dev, i);
> +	return NULL;
> +}
> +EXPORT_SYMBOL_GPL(rtrs_iu_alloc);
> +
> +void rtrs_iu_free(struct rtrs_iu *ius, enum dma_data_direction dir,
> +		   struct ib_device *ibdev, u32 queue_size)
> +{
> +	struct rtrs_iu *iu;
> +	int i;
> +
> +	if (!ius)
> +		return;
> +
> +	for (i = 0; i < queue_size; i++) {
> +		iu = &ius[i];
> +		ib_dma_unmap_single(ibdev, iu->dma_addr, iu->size, dir);
> +		kfree(iu->buf);
> +	}
> +	kfree(ius);
> +}
> +EXPORT_SYMBOL_GPL(rtrs_iu_free);
> +
> +int rtrs_iu_post_recv(struct rtrs_con *con, struct rtrs_iu *iu)
> +{
> +	struct rtrs_sess *sess = con->sess;
> +	struct ib_recv_wr wr;
> +	struct ib_sge list;
> +
> +	list.addr   = iu->dma_addr;
> +	list.length = iu->size;
> +	list.lkey   = sess->dev->ib_pd->local_dma_lkey;
> +
> +	if (WARN_ON(list.length == 0)) {
> +		rtrs_wrn(con->sess,
> +			  "Posting receive work request failed, sg list is empty\n");

Both WARN_ON and warning message?

Thanks
Jinpu Wang Jan. 20, 2020, 11:32 a.m. UTC | #2
On Sun, Jan 19, 2020 at 3:48 PM Leon Romanovsky <leon@kernel.org> wrote:
>
> On Thu, Jan 16, 2020 at 01:58:54PM +0100, Jack Wang wrote:
> > From: Jack Wang <jinpu.wang@cloud.ionos.com>
> >
> > This is a set of library functions existing as a rtrs-core module,
> > used by client and server modules.
> >
> > Mainly these functions wrap IB and RDMA calls and provide a bit higher
> > abstraction for implementing of RTRS protocol on client or server
> > sides.
> >
> > Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
> > Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
> > ---
> >  drivers/infiniband/ulp/rtrs/rtrs.c | 597 +++++++++++++++++++++++++++++
> >  1 file changed, 597 insertions(+)
> >  create mode 100644 drivers/infiniband/ulp/rtrs/rtrs.c
> >
> > diff --git a/drivers/infiniband/ulp/rtrs/rtrs.c b/drivers/infiniband/ulp/rtrs/rtrs.c
> > new file mode 100644
> > index 000000000000..7b84d76e2a67
> > --- /dev/null
> > +++ b/drivers/infiniband/ulp/rtrs/rtrs.c
> > @@ -0,0 +1,597 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * RDMA Transport Layer
> > + *
> > + * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
> > + *
> > + * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
> > + *
> > + * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
> > + */
> > +#undef pr_fmt
> > +#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
> > +
> > +#include <linux/module.h>
> > +#include <linux/inet.h>
> > +
> > +#include "rtrs-pri.h"
> > +#include "rtrs-log.h"
> > +
> > +MODULE_DESCRIPTION("RDMA Transport Core");
> > +MODULE_LICENSE("GPL");
> > +
> > +struct rtrs_iu *rtrs_iu_alloc(u32 queue_size, size_t size, gfp_t gfp_mask,
> > +                           struct ib_device *dma_dev,
> > +                           enum dma_data_direction dir,
> > +                           void (*done)(struct ib_cq *cq, struct ib_wc *wc))
> > +{
> > +     struct rtrs_iu *ius, *iu;
> > +     int i;
> > +
> > +     WARN_ON(!queue_size);
> > +     ius = kcalloc(queue_size, sizeof(*ius), gfp_mask);
> > +     if (unlikely(!ius))
> > +             return NULL;
>
> Let's do not add useless WARN_ON() and unlikely to every error path.
I can remove the WARN_ON, but the unlikey for error case seems normal to use,
small size memory allocation is unlikely to fail.

> > +int rtrs_iu_post_recv(struct rtrs_con *con, struct rtrs_iu *iu)
> > +{
> > +     struct rtrs_sess *sess = con->sess;
> > +     struct ib_recv_wr wr;
> > +     struct ib_sge list;
> > +
> > +     list.addr   = iu->dma_addr;
> > +     list.length = iu->size;
> > +     list.lkey   = sess->dev->ib_pd->local_dma_lkey;
> > +
> > +     if (WARN_ON(list.length == 0)) {
> > +             rtrs_wrn(con->sess,
> > +                       "Posting receive work request failed, sg list is empty\n");
>
> Both WARN_ON and warning message?
Will remove the WARN_ON.

Thanks Leon.
Leon Romanovsky Jan. 20, 2020, 1:30 p.m. UTC | #3
On Mon, Jan 20, 2020 at 12:32:00PM +0100, Jinpu Wang wrote:
> On Sun, Jan 19, 2020 at 3:48 PM Leon Romanovsky <leon@kernel.org> wrote:
> >
> > On Thu, Jan 16, 2020 at 01:58:54PM +0100, Jack Wang wrote:
> > > From: Jack Wang <jinpu.wang@cloud.ionos.com>
> > >
> > > This is a set of library functions existing as a rtrs-core module,
> > > used by client and server modules.
> > >
> > > Mainly these functions wrap IB and RDMA calls and provide a bit higher
> > > abstraction for implementing of RTRS protocol on client or server
> > > sides.
> > >
> > > Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
> > > Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
> > > ---
> > >  drivers/infiniband/ulp/rtrs/rtrs.c | 597 +++++++++++++++++++++++++++++
> > >  1 file changed, 597 insertions(+)
> > >  create mode 100644 drivers/infiniband/ulp/rtrs/rtrs.c
> > >
> > > diff --git a/drivers/infiniband/ulp/rtrs/rtrs.c b/drivers/infiniband/ulp/rtrs/rtrs.c
> > > new file mode 100644
> > > index 000000000000..7b84d76e2a67
> > > --- /dev/null
> > > +++ b/drivers/infiniband/ulp/rtrs/rtrs.c
> > > @@ -0,0 +1,597 @@
> > > +// SPDX-License-Identifier: GPL-2.0-or-later
> > > +/*
> > > + * RDMA Transport Layer
> > > + *
> > > + * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
> > > + *
> > > + * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
> > > + *
> > > + * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
> > > + */
> > > +#undef pr_fmt
> > > +#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
> > > +
> > > +#include <linux/module.h>
> > > +#include <linux/inet.h>
> > > +
> > > +#include "rtrs-pri.h"
> > > +#include "rtrs-log.h"
> > > +
> > > +MODULE_DESCRIPTION("RDMA Transport Core");
> > > +MODULE_LICENSE("GPL");
> > > +
> > > +struct rtrs_iu *rtrs_iu_alloc(u32 queue_size, size_t size, gfp_t gfp_mask,
> > > +                           struct ib_device *dma_dev,
> > > +                           enum dma_data_direction dir,
> > > +                           void (*done)(struct ib_cq *cq, struct ib_wc *wc))
> > > +{
> > > +     struct rtrs_iu *ius, *iu;
> > > +     int i;
> > > +
> > > +     WARN_ON(!queue_size);
> > > +     ius = kcalloc(queue_size, sizeof(*ius), gfp_mask);
> > > +     if (unlikely(!ius))
> > > +             return NULL;
> >
> > Let's do not add useless WARN_ON() and unlikely to every error path.
> I can remove the WARN_ON, but the unlikey for error case seems normal to use,
> small size memory allocation is unlikely to fail.

The unlikely() makes sense in data-path only and mostly it doesn't give
any performance advantage, kcalloc() in this function means that this
function is not performance oriented.

As general note, as long as this code will leave impression of
not-stable enough, we will have hard time to accept it. The overuse of
WARN_ON(), debug prints and micro-optimizations add to such feeling.

Thanks
Jinpu Wang Jan. 20, 2020, 2:08 p.m. UTC | #4
On Mon, Jan 20, 2020 at 2:30 PM Leon Romanovsky <leon@kernel.org> wrote:
>
> On Mon, Jan 20, 2020 at 12:32:00PM +0100, Jinpu Wang wrote:
> > On Sun, Jan 19, 2020 at 3:48 PM Leon Romanovsky <leon@kernel.org> wrote:
> > >
> > > On Thu, Jan 16, 2020 at 01:58:54PM +0100, Jack Wang wrote:
> > > > From: Jack Wang <jinpu.wang@cloud.ionos.com>
> > > >
> > > > This is a set of library functions existing as a rtrs-core module,
> > > > used by client and server modules.
> > > >
> > > > Mainly these functions wrap IB and RDMA calls and provide a bit higher
> > > > abstraction for implementing of RTRS protocol on client or server
> > > > sides.
> > > >
> > > > Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
> > > > Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
> > > > ---
> > > >  drivers/infiniband/ulp/rtrs/rtrs.c | 597 +++++++++++++++++++++++++++++
> > > >  1 file changed, 597 insertions(+)
> > > >  create mode 100644 drivers/infiniband/ulp/rtrs/rtrs.c
> > > >
> > > > diff --git a/drivers/infiniband/ulp/rtrs/rtrs.c b/drivers/infiniband/ulp/rtrs/rtrs.c
> > > > new file mode 100644
> > > > index 000000000000..7b84d76e2a67
> > > > --- /dev/null
> > > > +++ b/drivers/infiniband/ulp/rtrs/rtrs.c
> > > > @@ -0,0 +1,597 @@
> > > > +// SPDX-License-Identifier: GPL-2.0-or-later
> > > > +/*
> > > > + * RDMA Transport Layer
> > > > + *
> > > > + * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
> > > > + *
> > > > + * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
> > > > + *
> > > > + * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
> > > > + */
> > > > +#undef pr_fmt
> > > > +#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
> > > > +
> > > > +#include <linux/module.h>
> > > > +#include <linux/inet.h>
> > > > +
> > > > +#include "rtrs-pri.h"
> > > > +#include "rtrs-log.h"
> > > > +
> > > > +MODULE_DESCRIPTION("RDMA Transport Core");
> > > > +MODULE_LICENSE("GPL");
> > > > +
> > > > +struct rtrs_iu *rtrs_iu_alloc(u32 queue_size, size_t size, gfp_t gfp_mask,
> > > > +                           struct ib_device *dma_dev,
> > > > +                           enum dma_data_direction dir,
> > > > +                           void (*done)(struct ib_cq *cq, struct ib_wc *wc))
> > > > +{
> > > > +     struct rtrs_iu *ius, *iu;
> > > > +     int i;
> > > > +
> > > > +     WARN_ON(!queue_size);
> > > > +     ius = kcalloc(queue_size, sizeof(*ius), gfp_mask);
> > > > +     if (unlikely(!ius))
> > > > +             return NULL;
> > >
> > > Let's do not add useless WARN_ON() and unlikely to every error path.
> > I can remove the WARN_ON, but the unlikey for error case seems normal to use,
> > small size memory allocation is unlikely to fail.
>
> The unlikely() makes sense in data-path only and mostly it doesn't give
> any performance advantage, kcalloc() in this function means that this
> function is not performance oriented.
>

Thanks for the clarification, it is not in the data path, sure can be
removed, we will review the usage
and remove the unnecessary ones.
diff mbox series

Patch

diff --git a/drivers/infiniband/ulp/rtrs/rtrs.c b/drivers/infiniband/ulp/rtrs/rtrs.c
new file mode 100644
index 000000000000..7b84d76e2a67
--- /dev/null
+++ b/drivers/infiniband/ulp/rtrs/rtrs.c
@@ -0,0 +1,597 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RDMA Transport Layer
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ *
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ *
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+#undef pr_fmt
+#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
+
+#include <linux/module.h>
+#include <linux/inet.h>
+
+#include "rtrs-pri.h"
+#include "rtrs-log.h"
+
+MODULE_DESCRIPTION("RDMA Transport Core");
+MODULE_LICENSE("GPL");
+
+struct rtrs_iu *rtrs_iu_alloc(u32 queue_size, size_t size, gfp_t gfp_mask,
+			      struct ib_device *dma_dev,
+			      enum dma_data_direction dir,
+			      void (*done)(struct ib_cq *cq, struct ib_wc *wc))
+{
+	struct rtrs_iu *ius, *iu;
+	int i;
+
+	WARN_ON(!queue_size);
+	ius = kcalloc(queue_size, sizeof(*ius), gfp_mask);
+	if (unlikely(!ius))
+		return NULL;
+	for (i = 0; i < queue_size; i++) {
+		iu = &ius[i];
+		iu->buf = kzalloc(size, gfp_mask);
+		if (unlikely(!iu->buf))
+			goto err;
+
+		iu->dma_addr = ib_dma_map_single(dma_dev, iu->buf, size, dir);
+		if (unlikely(ib_dma_mapping_error(dma_dev, iu->dma_addr)))
+			goto err;
+
+		iu->cqe.done  = done;
+		iu->size      = size;
+		iu->direction = dir;
+	}
+	return ius;
+err:
+	rtrs_iu_free(ius, dir, dma_dev, i);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(rtrs_iu_alloc);
+
+void rtrs_iu_free(struct rtrs_iu *ius, enum dma_data_direction dir,
+		   struct ib_device *ibdev, u32 queue_size)
+{
+	struct rtrs_iu *iu;
+	int i;
+
+	if (!ius)
+		return;
+
+	for (i = 0; i < queue_size; i++) {
+		iu = &ius[i];
+		ib_dma_unmap_single(ibdev, iu->dma_addr, iu->size, dir);
+		kfree(iu->buf);
+	}
+	kfree(ius);
+}
+EXPORT_SYMBOL_GPL(rtrs_iu_free);
+
+int rtrs_iu_post_recv(struct rtrs_con *con, struct rtrs_iu *iu)
+{
+	struct rtrs_sess *sess = con->sess;
+	struct ib_recv_wr wr;
+	struct ib_sge list;
+
+	list.addr   = iu->dma_addr;
+	list.length = iu->size;
+	list.lkey   = sess->dev->ib_pd->local_dma_lkey;
+
+	if (WARN_ON(list.length == 0)) {
+		rtrs_wrn(con->sess,
+			  "Posting receive work request failed, sg list is empty\n");
+		return -EINVAL;
+	}
+	wr = (struct ib_recv_wr) {
+	.wr_cqe  = &iu->cqe,
+	.sg_list = &list,
+	.num_sge = 1,
+	};
+
+	return ib_post_recv(con->qp, &wr, NULL);
+}
+EXPORT_SYMBOL_GPL(rtrs_iu_post_recv);
+
+int rtrs_post_recv_empty(struct rtrs_con *con, struct ib_cqe *cqe)
+{
+	struct ib_recv_wr wr;
+
+	wr = (struct ib_recv_wr) {
+	.wr_cqe  = cqe,
+	};
+
+	return ib_post_recv(con->qp, &wr, NULL);
+}
+EXPORT_SYMBOL_GPL(rtrs_post_recv_empty);
+
+int rtrs_iu_post_send(struct rtrs_con *con, struct rtrs_iu *iu, size_t size,
+		       struct ib_send_wr *head)
+{
+	struct rtrs_sess *sess = con->sess;
+	struct ib_send_wr wr;
+	struct ib_sge list;
+
+	if (WARN_ON(size == 0))
+		return -EINVAL;
+
+	list.addr   = iu->dma_addr;
+	list.length = size;
+	list.lkey   = sess->dev->ib_pd->local_dma_lkey;
+
+	wr = (struct ib_send_wr) {
+	.wr_cqe     = &iu->cqe,
+	.sg_list    = &list,
+	.num_sge    = 1,
+	.opcode     = IB_WR_SEND,
+	.send_flags = IB_SEND_SIGNALED,
+	};
+
+	if (head) {
+		struct ib_send_wr *tail = head;
+
+		while (tail->next)
+			tail = tail->next;
+		tail->next = &wr;
+	} else {
+		head = &wr;
+	}
+
+	return ib_post_send(con->qp, head, NULL);
+}
+EXPORT_SYMBOL_GPL(rtrs_iu_post_send);
+
+int rtrs_iu_post_rdma_write_imm(struct rtrs_con *con, struct rtrs_iu *iu,
+				 struct ib_sge *sge, unsigned int num_sge,
+				 u32 rkey, u64 rdma_addr, u32 imm_data,
+				 enum ib_send_flags flags,
+				 struct ib_send_wr *head)
+{
+	struct ib_rdma_wr wr;
+	int i;
+
+	wr = (struct ib_rdma_wr) {
+	.wr.wr_cqe	  = &iu->cqe,
+	.wr.sg_list	  = sge,
+	.wr.num_sge	  = num_sge,
+	.rkey		  = rkey,
+	.remote_addr	  = rdma_addr,
+	.wr.opcode	  = IB_WR_RDMA_WRITE_WITH_IMM,
+	.wr.ex.imm_data = cpu_to_be32(imm_data),
+	.wr.send_flags  = flags,
+	};
+
+	/*
+	 * If one of the sges has 0 size, the operation will fail with an
+	 * length error
+	 */
+	for (i = 0; i < num_sge; i++)
+		if (WARN_ON(sge[i].length == 0))
+			return -EINVAL;
+
+	if (head) {
+		struct ib_send_wr *tail = head;
+
+		while (tail->next)
+			tail = tail->next;
+		tail->next = &wr.wr;
+	} else {
+		head = &wr.wr;
+	}
+
+	return ib_post_send(con->qp, head, NULL);
+}
+EXPORT_SYMBOL_GPL(rtrs_iu_post_rdma_write_imm);
+
+int rtrs_post_rdma_write_imm_empty(struct rtrs_con *con, struct ib_cqe *cqe,
+				    u32 imm_data, enum ib_send_flags flags,
+				    struct ib_send_wr *head)
+{
+	struct ib_send_wr wr;
+
+	wr = (struct ib_send_wr) {
+	.wr_cqe	= cqe,
+	.send_flags	= flags,
+	.opcode	= IB_WR_RDMA_WRITE_WITH_IMM,
+	.ex.imm_data	= cpu_to_be32(imm_data),
+	};
+
+	if (head) {
+		struct ib_send_wr *tail = head;
+
+		while (tail->next)
+			tail = tail->next;
+		tail->next = &wr;
+	} else {
+		head = &wr;
+	}
+
+	return ib_post_send(con->qp, head, NULL);
+}
+EXPORT_SYMBOL_GPL(rtrs_post_rdma_write_imm_empty);
+
+static void qp_event_handler(struct ib_event *ev, void *ctx)
+{
+	struct rtrs_con *con = ctx;
+
+	switch (ev->event) {
+	case IB_EVENT_COMM_EST:
+		rtrs_info(con->sess, "QP event %s (%d) received\n",
+			   ib_event_msg(ev->event), ev->event);
+		rdma_notify(con->cm_id, IB_EVENT_COMM_EST);
+		break;
+	default:
+		rtrs_info(con->sess, "Unhandled QP event %s (%d) received\n",
+			   ib_event_msg(ev->event), ev->event);
+		break;
+	}
+}
+
+static int create_cq(struct rtrs_con *con, int cq_vector, u16 cq_size,
+		     enum ib_poll_context poll_ctx)
+{
+	struct rdma_cm_id *cm_id = con->cm_id;
+	struct ib_cq *cq;
+
+	cq = ib_alloc_cq(cm_id->device, con, cq_size,
+			 cq_vector, poll_ctx);
+	if (IS_ERR(cq)) {
+		rtrs_err(con->sess, "Creating completion queue failed, errno: %ld\n",
+			  PTR_ERR(cq));
+		return PTR_ERR(cq);
+	}
+	con->cq = cq;
+
+	return 0;
+}
+
+static int create_qp(struct rtrs_con *con, struct ib_pd *pd,
+		     u16 wr_queue_size, u32 max_sge)
+{
+	struct ib_qp_init_attr init_attr = {NULL};
+	struct rdma_cm_id *cm_id = con->cm_id;
+	int ret;
+
+	init_attr.cap.max_send_wr = wr_queue_size;
+	init_attr.cap.max_recv_wr = wr_queue_size;
+	init_attr.cap.max_recv_sge = 1;
+	init_attr.event_handler = qp_event_handler;
+	init_attr.qp_context = con;
+	init_attr.cap.max_send_sge = max_sge;
+
+	init_attr.qp_type = IB_QPT_RC;
+	init_attr.send_cq = con->cq;
+	init_attr.recv_cq = con->cq;
+	init_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
+
+	ret = rdma_create_qp(cm_id, pd, &init_attr);
+	if (unlikely(ret)) {
+		rtrs_err(con->sess, "Creating QP failed, err: %d\n", ret);
+		return ret;
+	}
+	con->qp = cm_id->qp;
+
+	return ret;
+}
+
+int rtrs_cq_qp_create(struct rtrs_sess *sess, struct rtrs_con *con,
+		       u32 max_send_sge, int cq_vector, u16 cq_size,
+		       u16 wr_queue_size, enum ib_poll_context poll_ctx)
+{
+	int err;
+
+	err = create_cq(con, cq_vector, cq_size, poll_ctx);
+	if (unlikely(err))
+		return err;
+
+	err = create_qp(con, sess->dev->ib_pd, wr_queue_size, max_send_sge);
+	if (unlikely(err)) {
+		ib_free_cq(con->cq);
+		con->cq = NULL;
+		return err;
+	}
+	con->sess = sess;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtrs_cq_qp_create);
+
+void rtrs_cq_qp_destroy(struct rtrs_con *con)
+{
+	if (con->qp) {
+		rdma_destroy_qp(con->cm_id);
+		con->qp = NULL;
+	}
+	if (con->cq) {
+		ib_free_cq(con->cq);
+		con->cq = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(rtrs_cq_qp_destroy);
+
+static void schedule_hb(struct rtrs_sess *sess)
+{
+	queue_delayed_work(sess->hb_wq, &sess->hb_dwork,
+			   msecs_to_jiffies(sess->hb_interval_ms));
+}
+
+void rtrs_send_hb_ack(struct rtrs_sess *sess)
+{
+	struct rtrs_con *usr_con = sess->con[0];
+	u32 imm;
+	int err;
+
+	imm = rtrs_to_imm(RTRS_HB_ACK_IMM, 0);
+	err = rtrs_post_rdma_write_imm_empty(usr_con, sess->hb_cqe, imm,
+					      IB_SEND_SIGNALED, NULL);
+	if (unlikely(err)) {
+		sess->hb_err_handler(usr_con);
+		return;
+	}
+}
+EXPORT_SYMBOL_GPL(rtrs_send_hb_ack);
+
+static void hb_work(struct work_struct *work)
+{
+	struct rtrs_con *usr_con;
+	struct rtrs_sess *sess;
+	u32 imm;
+	int err;
+
+	sess = container_of(to_delayed_work(work), typeof(*sess), hb_dwork);
+	usr_con = sess->con[0];
+
+	if (sess->hb_missed_cnt > sess->hb_missed_max) {
+		sess->hb_err_handler(usr_con);
+		return;
+	}
+	if (sess->hb_missed_cnt++) {
+		/* Reschedule work without sending hb */
+		schedule_hb(sess);
+		return;
+	}
+	imm = rtrs_to_imm(RTRS_HB_MSG_IMM, 0);
+	err = rtrs_post_rdma_write_imm_empty(usr_con, sess->hb_cqe, imm,
+					      IB_SEND_SIGNALED, NULL);
+	if (unlikely(err)) {
+		sess->hb_err_handler(usr_con);
+		return;
+	}
+
+	schedule_hb(sess);
+}
+
+void rtrs_init_hb(struct rtrs_sess *sess, struct ib_cqe *cqe,
+		   unsigned int interval_ms, unsigned int missed_max,
+		   rtrs_hb_handler_t *err_handler,
+		   struct workqueue_struct *wq)
+{
+	sess->hb_cqe = cqe;
+	sess->hb_interval_ms = interval_ms;
+	sess->hb_err_handler = err_handler;
+	sess->hb_wq = wq;
+	sess->hb_missed_max = missed_max;
+	sess->hb_missed_cnt = 0;
+	INIT_DELAYED_WORK(&sess->hb_dwork, hb_work);
+}
+EXPORT_SYMBOL_GPL(rtrs_init_hb);
+
+void rtrs_start_hb(struct rtrs_sess *sess)
+{
+	schedule_hb(sess);
+}
+EXPORT_SYMBOL_GPL(rtrs_start_hb);
+
+void rtrs_stop_hb(struct rtrs_sess *sess)
+{
+	cancel_delayed_work_sync(&sess->hb_dwork);
+	sess->hb_missed_cnt = 0;
+	sess->hb_missed_max = 0;
+}
+EXPORT_SYMBOL_GPL(rtrs_stop_hb);
+
+static int rtrs_str_gid_to_sockaddr(const char *addr, size_t len,
+				     short port, struct sockaddr_storage *dst)
+{
+	struct sockaddr_ib *dst_ib = (struct sockaddr_ib *)dst;
+	int ret;
+
+	/*
+	 * We can use some of the IPv6 functions since GID is a valid
+	 * IPv6 address format
+	 */
+	ret = in6_pton(addr, len, dst_ib->sib_addr.sib_raw, '\0', NULL);
+	if (ret == 0)
+		return -EINVAL;
+
+	dst_ib->sib_family = AF_IB;
+	/*
+	 * Use the same TCP server port number as the IB service ID
+	 * on the IB port space range
+	 */
+	dst_ib->sib_sid = cpu_to_be64(RDMA_IB_IP_PS_IB | port);
+	dst_ib->sib_sid_mask = cpu_to_be64(0xffffffffffffffffULL);
+	dst_ib->sib_pkey = cpu_to_be16(0xffff);
+
+	return 0;
+}
+
+/**
+ * rtrs_str_to_sockaddr() - Convert rtrs address string to sockaddr
+ * @addr:	String representation of an addr (IPv4, IPv6 or IB GID):
+ *              - "ip:192.168.1.1"
+ *              - "ip:fe80::200:5aee:feaa:20a2"
+ *              - "gid:fe80::200:5aee:feaa:20a2"
+ * @len:        String address length
+ * @port:	Destination port
+ * @dst:	Destination sockaddr structure
+ *
+ * Returns 0 if conversion successful. Non-zero on error.
+ */
+static int rtrs_str_to_sockaddr(const char *addr, size_t len,
+				 short port, struct sockaddr_storage *dst)
+{
+	if (strncmp(addr, "gid:", 4) == 0) {
+		return rtrs_str_gid_to_sockaddr(addr + 4, len - 4, port, dst);
+	} else if (strncmp(addr, "ip:", 3) == 0) {
+		char port_str[8];
+		char *cpy;
+		int err;
+
+		snprintf(port_str, sizeof(port_str), "%u", port);
+		cpy = kstrndup(addr + 3, len - 3, GFP_KERNEL);
+		err = cpy ? inet_pton_with_scope(&init_net, AF_UNSPEC,
+						 cpy, port_str, dst) : -ENOMEM;
+		kfree(cpy);
+
+		return err;
+	}
+	return -EPROTONOSUPPORT;
+}
+
+int sockaddr_to_str(const struct sockaddr *addr, char *buf, size_t len)
+{
+	int cnt;
+
+	switch (addr->sa_family) {
+	case AF_IB:
+		cnt = scnprintf(buf, len, "gid:%pI6",
+			&((struct sockaddr_ib *)addr)->sib_addr.sib_raw);
+		return cnt;
+	case AF_INET:
+		cnt = scnprintf(buf, len, "ip:%pI4",
+			&((struct sockaddr_in *)addr)->sin_addr);
+		return cnt;
+	case AF_INET6:
+		cnt = scnprintf(buf, len, "ip:%pI6c",
+			  &((struct sockaddr_in6 *)addr)->sin6_addr);
+		return cnt;
+	}
+	cnt = scnprintf(buf, len, "<invalid address family>");
+	pr_err("Invalid address family\n");
+	return cnt;
+}
+EXPORT_SYMBOL(sockaddr_to_str);
+
+int rtrs_addr_to_sockaddr(const char *str, size_t len, short port,
+			   struct rtrs_addr *addr)
+{
+	const char *d;
+
+	d = strchr(str, ',');
+	if (!d)
+		d = strchr(str, '@');
+	if (d) {
+		if (rtrs_str_to_sockaddr(str, d - str, 0, addr->src))
+			return -EINVAL;
+		d += 1;
+		len -= d - str;
+		str  = d;
+
+	} else {
+		addr->src = NULL;
+	}
+	return rtrs_str_to_sockaddr(str, len, port, addr->dst);
+}
+EXPORT_SYMBOL(rtrs_addr_to_sockaddr);
+
+void rtrs_rdma_dev_pd_init(enum ib_pd_flags pd_flags,
+			    struct rtrs_rdma_dev_pd *pool)
+{
+	WARN_ON(pool->ops && (!pool->ops->alloc ^ !pool->ops->free));
+	INIT_LIST_HEAD(&pool->list);
+	mutex_init(&pool->mutex);
+	pool->pd_flags = pd_flags;
+}
+EXPORT_SYMBOL(rtrs_rdma_dev_pd_init);
+
+void rtrs_rdma_dev_pd_deinit(struct rtrs_rdma_dev_pd *pool)
+{
+	mutex_destroy(&pool->mutex);
+	WARN_ON(!list_empty(&pool->list));
+}
+EXPORT_SYMBOL(rtrs_rdma_dev_pd_deinit);
+
+static void dev_free(struct kref *ref)
+{
+	struct rtrs_rdma_dev_pd *pool;
+	struct rtrs_ib_dev *dev;
+
+	dev = container_of(ref, typeof(*dev), ref);
+	pool = dev->pool;
+
+	mutex_lock(&pool->mutex);
+	list_del(&dev->entry);
+	mutex_unlock(&pool->mutex);
+
+	if (pool->ops && pool->ops->deinit)
+		pool->ops->deinit(dev);
+
+	ib_dealloc_pd(dev->ib_pd);
+
+	if (pool->ops && pool->ops->free)
+		pool->ops->free(dev);
+	else
+		kfree(dev);
+}
+
+int rtrs_ib_dev_put(struct rtrs_ib_dev *dev)
+{
+	return kref_put(&dev->ref, dev_free);
+}
+EXPORT_SYMBOL(rtrs_ib_dev_put);
+
+static int rtrs_ib_dev_get(struct rtrs_ib_dev *dev)
+{
+	return kref_get_unless_zero(&dev->ref);
+}
+
+struct rtrs_ib_dev *
+rtrs_ib_dev_find_or_add(struct ib_device *ib_dev,
+			 struct rtrs_rdma_dev_pd *pool)
+{
+	struct rtrs_ib_dev *dev;
+
+	mutex_lock(&pool->mutex);
+	list_for_each_entry(dev, &pool->list, entry) {
+		if (dev->ib_dev->node_guid == ib_dev->node_guid &&
+		    rtrs_ib_dev_get(dev))
+			goto out_unlock;
+	}
+	if (pool->ops && pool->ops->alloc)
+		dev = pool->ops->alloc();
+	else
+		dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (IS_ERR_OR_NULL(dev))
+		goto out_err;
+
+	kref_init(&dev->ref);
+	dev->pool = pool;
+	dev->ib_dev = ib_dev;
+	dev->ib_pd = ib_alloc_pd(ib_dev, pool->pd_flags);
+	if (IS_ERR(dev->ib_pd))
+		goto out_free_dev;
+
+	if (pool->ops && pool->ops->init && pool->ops->init(dev))
+		goto out_free_pd;
+
+	list_add(&dev->entry, &pool->list);
+out_unlock:
+	mutex_unlock(&pool->mutex);
+	return dev;
+
+out_free_pd:
+	ib_dealloc_pd(dev->ib_pd);
+out_free_dev:
+	if (pool->ops && pool->ops->free)
+		pool->ops->free(dev);
+	else
+		kfree(dev);
+out_err:
+	mutex_unlock(&pool->mutex);
+	return NULL;
+}
+EXPORT_SYMBOL(rtrs_ib_dev_find_or_add);