diff mbox series

[v5,04/13] SIW object management

Message ID 20190219100903.15408-5-bmt@zurich.ibm.com (mailing list archive)
State Superseded
Delegated to: Jason Gunthorpe
Headers show
Series SIW: Request for Comments | expand

Commit Message

Bernard Metzler Feb. 19, 2019, 10:08 a.m. UTC 
Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
---
 drivers/infiniband/sw/siw/siw_obj.c | 341 ++++++++++++++++++++++++++++
 drivers/infiniband/sw/siw/siw_obj.h | 226 ++++++++++++++++++
 2 files changed, 567 insertions(+)
 create mode 100644 drivers/infiniband/sw/siw/siw_obj.c
 create mode 100644 drivers/infiniband/sw/siw/siw_obj.h

Comments

Leon Romanovsky Feb. 24, 2019, 1:17 p.m. UTC | #1 
On Tue, Feb 19, 2019 at 11:08:54AM +0100, Bernard Metzler wrote:
> Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
> ---
>  drivers/infiniband/sw/siw/siw_obj.c | 341 ++++++++++++++++++++++++++++
>  drivers/infiniband/sw/siw/siw_obj.h | 226 ++++++++++++++++++
>  2 files changed, 567 insertions(+)
>  create mode 100644 drivers/infiniband/sw/siw/siw_obj.c
>  create mode 100644 drivers/infiniband/sw/siw/siw_obj.h
>
> diff --git a/drivers/infiniband/sw/siw/siw_obj.c b/drivers/infiniband/sw/siw/siw_obj.c
> new file mode 100644
> index 000000000000..a086a3c9aca7
> --- /dev/null
> +++ b/drivers/infiniband/sw/siw/siw_obj.c
> @@ -0,0 +1,341 @@
> +// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
> +/*
> + * Software iWARP device driver
> + *
> + * Authors: Bernard Metzler <bmt@zurich.ibm.com>
> + *
> + * Copyright (c) 2008-2018, IBM Corporation
> + *
> + * 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
> + * 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.
> + *
> + *   - Neither the name of IBM nor the names of its contributors may be
> + *     used to endorse or promote products derived from this software without
> + *     specific prior written permission.
> + *
> + * 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 <linux/spinlock.h>
> +#include <linux/kref.h>
> +#include <linux/vmalloc.h>
> +
> +#include "siw.h"
> +#include "siw_obj.h"
> +#include "siw_cm.h"
> +
> +void siw_objhdr_init(struct siw_objhdr *hdr)
> +{
> +	kref_init(&hdr->ref);
> +}
> +
> +void siw_idr_init(struct siw_device *sdev)
> +{
> +	spin_lock_init(&sdev->lock);
> +
> +	idr_init(&sdev->qp_idr);
> +	idr_init(&sdev->cq_idr);
> +	idr_init(&sdev->pd_idr);
> +	idr_init(&sdev->mem_idr);
> +}
> +
> +void siw_idr_release(struct siw_device *sdev)
> +{
> +	idr_destroy(&sdev->qp_idr);
> +	idr_destroy(&sdev->cq_idr);
> +	idr_destroy(&sdev->pd_idr);
> +	idr_destroy(&sdev->mem_idr);
> +}
> +
> +static int siw_add_obj(spinlock_t *lock, struct idr *idr,
> +		       struct siw_objhdr *obj)
> +{
> +	unsigned long flags;
> +	int id, min_id;
> +
> +	get_random_bytes(&min_id, 4);
> +	min_id &= 0x00FFFFFF;
> +again:
> +	spin_lock_irqsave(lock, flags);
> +	id = idr_alloc(idr, obj, min_id, 0x00FFFFFF - 1, GFP_KERNEL);
> +	spin_unlock_irqrestore(lock, flags);
> +
> +	if (id > 0) {
> +		siw_objhdr_init(obj);
> +		obj->id = id;
> +	} else if (id == -ENOSPC && min_id != 1) {
> +		min_id = 1;
> +		goto again;
> +	} else {
> +		pr_warn("SIW: object ID space\n");
> +	}
> +	if (id > 0)
> +		return 0;
> +
> +	return id == 0 ? -ENOSPC : id;
> +}
> +
> +int siw_qp_add(struct siw_device *sdev, struct siw_qp *qp)
> +{
> +	int rv = siw_add_obj(&sdev->lock, &sdev->qp_idr, &qp->hdr);
> +
> +	if (!rv) {
> +		qp->hdr.sdev = sdev;
> +		siw_dbg_obj(qp, "new QP\n");
> +	}
> +	return rv;
> +}
> +
> +int siw_cq_add(struct siw_device *sdev, struct siw_cq *cq)
> +{
> +	int rv = siw_add_obj(&sdev->lock, &sdev->cq_idr, &cq->hdr);
> +
> +	if (!rv) {
> +		cq->hdr.sdev = sdev;
> +		siw_dbg_obj(cq, "new CQ\n");
> +	}
> +	return rv;
> +}
> +
> +int siw_pd_add(struct siw_device *sdev, struct siw_pd *pd)
> +{
> +	int rv = siw_add_obj(&sdev->lock, &sdev->pd_idr, &pd->hdr);
> +
> +	if (!rv) {
> +		pd->hdr.sdev = sdev;
> +		siw_dbg_obj(pd, "new PD\n");
> +	}
> +	return rv;
> +}
> +
> +/*
> + * Stag lookup is based on its index part only (24 bits).
> + * The code avoids special Stag of zero and tries to randomize
> + * STag values between 1 and SIW_STAG_MAX_INDEX.
> + */
> +int siw_mem_add(struct siw_device *sdev, struct siw_mem *m)
> +{
> +	unsigned long flags;
> +	int id, min_id, max_id = 0x00FFFFFF;
> +
> +	do {
> +		get_random_bytes(&min_id, 4);
> +		min_id &= 0x00FFFFFF;
> +	} while (min_id <= 0);
> +again:
> +	spin_lock_irqsave(&sdev->lock, flags);
> +	id = idr_alloc(&sdev->mem_idr, m, min_id, max_id, GFP_KERNEL);
> +	spin_unlock_irqrestore(&sdev->lock, flags);
> +
> +	if (id == -ENOMEM)
> +		return -ENOMEM;
> +
> +	if (id == -ENOSPC) {
> +		max_id = min_id;
> +		min_id /= 2;
> +		if (min_id <= 0) {
> +			pr_warn("SIW: memory ID space\n");
> +			return -ENOSPC;
> +		}
> +		goto again;
> +	}
> +	siw_objhdr_init(&m->hdr);
> +	m->hdr.id = id;
> +	m->hdr.sdev = sdev;
> +
> +	siw_dbg_obj(m, "new MEM object\n");
> +
> +	return 0;
> +}
> +
> +void siw_remove_obj(spinlock_t *lock, struct idr *idr,
> +		      struct siw_objhdr *hdr)
> +{
> +	unsigned long	flags;
> +
> +	spin_lock_irqsave(lock, flags);
> +	idr_remove(idr, hdr->id);
> +	spin_unlock_irqrestore(lock, flags);
> +}
> +
> +/********** routines to put objs back and free if no ref left *****/
> +
> +void siw_free_cq(struct kref *ref)
> +{
> +	struct siw_cq *cq =
> +		(container_of(container_of(ref, struct siw_objhdr, ref),
> +			      struct siw_cq, hdr));
> +
> +	siw_dbg_obj(cq, "free cq\n");
> +
> +	atomic_dec(&cq->hdr.sdev->num_cq);
> +	if (cq->queue)
> +		vfree(cq->queue);
> +	kfree(cq);
> +}
> +
> +void siw_free_qp(struct kref *ref)
> +{
> +	struct siw_qp *qp =
> +		container_of(container_of(ref, struct siw_objhdr, ref),
> +			     struct siw_qp, hdr);
> +	struct siw_device *sdev = qp->hdr.sdev;
> +	unsigned long flags;
> +
> +	siw_dbg_obj(qp, "free qp\n");
> +
> +	if (qp->cep)
> +		siw_cep_put(qp->cep);
> +
> +	siw_remove_obj(&sdev->lock, &sdev->qp_idr, &qp->hdr);
> +
> +	spin_lock_irqsave(&sdev->lock, flags);
> +	list_del(&qp->devq);
> +	spin_unlock_irqrestore(&sdev->lock, flags);
> +
> +	if (qp->sendq)
> +		vfree(qp->sendq);
> +	if (qp->recvq)
> +		vfree(qp->recvq);
> +	if (qp->irq)
> +		vfree(qp->irq);
> +	if (qp->orq)
> +		vfree(qp->orq);
> +
> +	siw_put_tx_cpu(qp->tx_cpu);
> +
> +	atomic_dec(&sdev->num_qp);
> +	kfree(qp);
> +}
> +
> +void siw_free_pd(struct kref *ref)
> +{
> +	struct siw_pd	*pd =
> +		container_of(container_of(ref, struct siw_objhdr, ref),
> +			     struct siw_pd, hdr);
> +
> +	siw_dbg_obj(pd, "free PD\n");
> +
> +	atomic_dec(&pd->hdr.sdev->num_pd);
> +}
> +
> +void siw_free_mem(struct kref *ref)
> +{
> +	struct siw_mem *m;
> +	struct siw_device *sdev;
> +
> +	m = container_of(container_of(ref, struct siw_objhdr, ref),
> +			 struct siw_mem, hdr);
> +	sdev = m->hdr.sdev;
> +
> +	siw_dbg_obj(m, "free mem\n");
> +
> +	atomic_dec(&sdev->num_mr);
> +
> +	if (SIW_MEM_IS_MW(m)) {
> +		struct siw_mw *mw = container_of(m, struct siw_mw, mem);
> +
> +		kfree_rcu(mw, rcu);
> +	} else {
> +		struct siw_mr *mr = container_of(m, struct siw_mr, mem);
> +		unsigned long flags;
> +
> +		siw_dbg(m->hdr.sdev, "[MEM %d]: has pbl: %s\n",
> +			OBJ_ID(m), mr->mem.is_pbl ? "y" : "n");
> +
> +		if (mr->pd)
> +			siw_pd_put(mr->pd);
> +
> +		if (mr->mem_obj) {
> +			if (mr->mem.is_pbl == 0)
> +				siw_umem_release(mr->umem);
> +			else
> +				siw_pbl_free(mr->pbl);
> +
> +		}
> +		spin_lock_irqsave(&sdev->lock, flags);
> +		list_del(&mr->devq);
> +		spin_unlock_irqrestore(&sdev->lock, flags);
> +
> +		kfree_rcu(mr, rcu);
> +	}
> +}
> +
> +void siw_wqe_put_mem(struct siw_wqe *wqe, enum siw_opcode op)
> +{
> +	switch (op) {
> +
> +	case SIW_OP_SEND:
> +	case SIW_OP_WRITE:
> +	case SIW_OP_SEND_WITH_IMM:
> +	case SIW_OP_SEND_REMOTE_INV:
> +	case SIW_OP_READ:
> +	case SIW_OP_READ_LOCAL_INV:
> +		if (!(wqe->sqe.flags & SIW_WQE_INLINE))
> +			siw_unref_mem_sgl(wqe->mem, wqe->sqe.num_sge);
> +		break;
> +
> +	case SIW_OP_RECEIVE:
> +		siw_unref_mem_sgl(wqe->mem, wqe->rqe.num_sge);
> +		break;
> +
> +	case SIW_OP_READ_RESPONSE:
> +		siw_unref_mem_sgl(wqe->mem, 1);
> +		break;
> +
> +	default:
> +		/*
> +		 * SIW_OP_INVAL_STAG and SIW_OP_REG_MR
> +		 * do not hold memory references
> +		 */
> +		break;
> +	}
> +}
> +
> +int siw_invalidate_stag(struct siw_pd *pd, u32 stag)
> +{
> +	u32 stag_idx = stag >> 8;
> +	struct siw_mem *mem = siw_mem_id2obj(pd->hdr.sdev, stag_idx);
> +	int rv = 0;
> +
> +	if (unlikely(!mem)) {
> +		siw_dbg(pd->hdr.sdev, "stag %u unknown\n", stag_idx);
> +		return -EINVAL;
> +	}
> +	if (unlikely(siw_mem2mr(mem)->pd != pd)) {
> +		siw_dbg(pd->hdr.sdev, "pd mismatch for stag %u\n", stag_idx);
> +		rv = -EACCES;
> +		goto out;
> +	}
> +	/*
> +	 * Per RDMA verbs definition, an STag may already be in invalid
> +	 * state if invalidation is requested. So no state check here.
> +	 */
> +	mem->stag_valid = 0;
> +
> +	siw_dbg(pd->hdr.sdev, "stag %u now valid\n", stag_idx);
> +out:
> +	siw_mem_put(mem);
> +	return rv;
> +}
> diff --git a/drivers/infiniband/sw/siw/siw_obj.h b/drivers/infiniband/sw/siw/siw_obj.h
> new file mode 100644
> index 000000000000..ed0575c22283
> --- /dev/null
> +++ b/drivers/infiniband/sw/siw/siw_obj.h
> @@ -0,0 +1,226 @@
> +// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
> +/*
> + * Software iWARP device driver
> + *
> + * Authors: Bernard Metzler <bmt@zurich.ibm.com>
> + *
> + * Copyright (c) 2008-2018, IBM Corporation
> + *
> + * 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
> + * 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.
> + *
> + *   - Neither the name of IBM nor the names of its contributors may be
> + *     used to endorse or promote products derived from this software without
> + *     specific prior written permission.
> + *
> + * 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.
> + */
> +
> +#ifndef _SIW_OBJ_H
> +#define _SIW_OBJ_H
> +
> +#include <linux/idr.h>
> +#include <linux/rwsem.h>
> +#include <linux/version.h>
> +#include <linux/sched.h>
> +#include <linux/semaphore.h>
> +
> +#include <rdma/ib_verbs.h>
> +
> +#include "siw_debug.h"
> +
> +extern void siw_free_qp(struct kref *ref);
> +extern void siw_free_pd(struct kref *ref);
> +extern void siw_free_cq(struct kref *ref);
> +extern void siw_free_mem(struct kref *ref);
> +
> +static inline struct siw_ucontext *to_siw_ctx(struct ib_ucontext *base_ctx)
> +{
> +	return container_of(base_ctx, struct siw_ucontext, ib_ucontext);
> +}
> +
> +static inline struct siw_qp *to_siw_qp(struct ib_qp *base_qp)
> +{
> +	return container_of(base_qp, struct siw_qp, base_qp);
> +}
> +
> +static inline struct siw_cq *to_siw_cq(struct ib_cq *base_cq)
> +{
> +	return container_of(base_cq, struct siw_cq, base_cq);
> +}
> +
> +static inline struct siw_srq *to_siw_srq(struct ib_srq *base_srq)
> +{
> +	return container_of(base_srq, struct siw_srq, base_srq);
> +}
> +
> +static inline struct siw_device *to_siw_dev(struct ib_device *base_dev)
> +{
> +	return container_of(base_dev, struct siw_device, base_dev);
> +}
> +
> +static inline struct siw_mr *to_siw_mr(struct ib_mr *base_mr)
> +{
> +	return container_of(base_mr, struct siw_mr, base_mr);
> +}
> +
> +static inline struct siw_pd *to_siw_pd(struct ib_pd *base_pd)
> +{
> +	return container_of(base_pd, struct siw_pd, base_pd);
> +}
> +
> +static inline void siw_cq_get(struct siw_cq *cq)
> +{
> +	kref_get(&cq->hdr.ref);
> +	siw_dbg_obj(cq, "new refcount: %d\n", kref_read(&cq->hdr.ref));
> +}
> +static inline void siw_qp_get(struct siw_qp *qp)
> +{
> +	kref_get(&qp->hdr.ref);
> +	siw_dbg_obj(qp, "new refcount: %d\n", kref_read(&qp->hdr.ref));
> +}
> +
> +static inline void siw_pd_get(struct siw_pd *pd)
> +{
> +	kref_get(&pd->hdr.ref);
> +	siw_dbg_obj(pd, "new refcount: %d\n", kref_read(&pd->hdr.ref));
> +}
> +
> +static inline void siw_mem_get(struct siw_mem *mem)
> +{
> +	kref_get(&mem->hdr.ref);
> +	siw_dbg_obj(mem, "new refcount: %d\n", kref_read(&mem->hdr.ref));
> +}

I think that all this kref code is not actually needed and IB/core handles it.

Thanks
Bernard Metzler Feb. 27, 2019, 12:06 p.m. UTC | #2 
-----"Leon Romanovsky" <leon@kernel.org> wrote: -----

>To: "Bernard Metzler" <bmt@zurich.ibm.com>
>From: "Leon Romanovsky" <leon@kernel.org>
>Date: 02/24/2019 02:17PM
>Cc: linux-rdma@vger.kernel.org
>Subject: Re: [PATCH v5 04/13] SIW object management
>
>On Tue, Feb 19, 2019 at 11:08:54AM +0100, Bernard Metzler wrote:
>> Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
>> ---
>>  drivers/infiniband/sw/siw/siw_obj.c | 341
>++++++++++++++++++++++++++++
>>  drivers/infiniband/sw/siw/siw_obj.h | 226 ++++++++++++++++++
>>  2 files changed, 567 insertions(+)
>>  create mode 100644 drivers/infiniband/sw/siw/siw_obj.c
>>  create mode 100644 drivers/infiniband/sw/siw/siw_obj.h
>>
>> diff --git a/drivers/infiniband/sw/siw/siw_obj.c
>b/drivers/infiniband/sw/siw/siw_obj.c
>> new file mode 100644
>> index 000000000000..a086a3c9aca7
>> --- /dev/null
>> +++ b/drivers/infiniband/sw/siw/siw_obj.c
>> @@ -0,0 +1,341 @@
>> +// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
>> +/*
>> + * Software iWARP device driver
>> + *
>> + * Authors: Bernard Metzler <bmt@zurich.ibm.com>
>> + *
>> + * Copyright (c) 2008-2018, IBM Corporation
>> + *
>> + * 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
>> + * 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.
>> + *
>> + *   - Neither the name of IBM nor the names of its contributors
>may be
>> + *     used to endorse or promote products derived from this
>software without
>> + *     specific prior written permission.
>> + *
>> + * 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 <linux/spinlock.h>
>> +#include <linux/kref.h>
>> +#include <linux/vmalloc.h>
>> +
>> +#include "siw.h"
>> +#include "siw_obj.h"
>> +#include "siw_cm.h"
>> +
>> +void siw_objhdr_init(struct siw_objhdr *hdr)
>> +{
>> +	kref_init(&hdr->ref);
>> +}
>> +
>> +void siw_idr_init(struct siw_device *sdev)
>> +{
>> +	spin_lock_init(&sdev->lock);
>> +
>> +	idr_init(&sdev->qp_idr);
>> +	idr_init(&sdev->cq_idr);
>> +	idr_init(&sdev->pd_idr);
>> +	idr_init(&sdev->mem_idr);
>> +}
>> +
>> +void siw_idr_release(struct siw_device *sdev)
>> +{
>> +	idr_destroy(&sdev->qp_idr);
>> +	idr_destroy(&sdev->cq_idr);
>> +	idr_destroy(&sdev->pd_idr);
>> +	idr_destroy(&sdev->mem_idr);
>> +}
>> +
>> +static int siw_add_obj(spinlock_t *lock, struct idr *idr,
>> +		       struct siw_objhdr *obj)
>> +{
>> +	unsigned long flags;
>> +	int id, min_id;
>> +
>> +	get_random_bytes(&min_id, 4);
>> +	min_id &= 0x00FFFFFF;
>> +again:
>> +	spin_lock_irqsave(lock, flags);
>> +	id = idr_alloc(idr, obj, min_id, 0x00FFFFFF - 1, GFP_KERNEL);
>> +	spin_unlock_irqrestore(lock, flags);
>> +
>> +	if (id > 0) {
>> +		siw_objhdr_init(obj);
>> +		obj->id = id;
>> +	} else if (id == -ENOSPC && min_id != 1) {
>> +		min_id = 1;
>> +		goto again;
>> +	} else {
>> +		pr_warn("SIW: object ID space\n");
>> +	}
>> +	if (id > 0)
>> +		return 0;
>> +
>> +	return id == 0 ? -ENOSPC : id;
>> +}
>> +
>> +int siw_qp_add(struct siw_device *sdev, struct siw_qp *qp)
>> +{
>> +	int rv = siw_add_obj(&sdev->lock, &sdev->qp_idr, &qp->hdr);
>> +
>> +	if (!rv) {
>> +		qp->hdr.sdev = sdev;
>> +		siw_dbg_obj(qp, "new QP\n");
>> +	}
>> +	return rv;
>> +}
>> +
>> +int siw_cq_add(struct siw_device *sdev, struct siw_cq *cq)
>> +{
>> +	int rv = siw_add_obj(&sdev->lock, &sdev->cq_idr, &cq->hdr);
>> +
>> +	if (!rv) {
>> +		cq->hdr.sdev = sdev;
>> +		siw_dbg_obj(cq, "new CQ\n");
>> +	}
>> +	return rv;
>> +}
>> +
>> +int siw_pd_add(struct siw_device *sdev, struct siw_pd *pd)
>> +{
>> +	int rv = siw_add_obj(&sdev->lock, &sdev->pd_idr, &pd->hdr);
>> +
>> +	if (!rv) {
>> +		pd->hdr.sdev = sdev;
>> +		siw_dbg_obj(pd, "new PD\n");
>> +	}
>> +	return rv;
>> +}
>> +
>> +/*
>> + * Stag lookup is based on its index part only (24 bits).
>> + * The code avoids special Stag of zero and tries to randomize
>> + * STag values between 1 and SIW_STAG_MAX_INDEX.
>> + */
>> +int siw_mem_add(struct siw_device *sdev, struct siw_mem *m)
>> +{
>> +	unsigned long flags;
>> +	int id, min_id, max_id = 0x00FFFFFF;
>> +
>> +	do {
>> +		get_random_bytes(&min_id, 4);
>> +		min_id &= 0x00FFFFFF;
>> +	} while (min_id <= 0);
>> +again:
>> +	spin_lock_irqsave(&sdev->lock, flags);
>> +	id = idr_alloc(&sdev->mem_idr, m, min_id, max_id, GFP_KERNEL);
>> +	spin_unlock_irqrestore(&sdev->lock, flags);
>> +
>> +	if (id == -ENOMEM)
>> +		return -ENOMEM;
>> +
>> +	if (id == -ENOSPC) {
>> +		max_id = min_id;
>> +		min_id /= 2;
>> +		if (min_id <= 0) {
>> +			pr_warn("SIW: memory ID space\n");
>> +			return -ENOSPC;
>> +		}
>> +		goto again;
>> +	}
>> +	siw_objhdr_init(&m->hdr);
>> +	m->hdr.id = id;
>> +	m->hdr.sdev = sdev;
>> +
>> +	siw_dbg_obj(m, "new MEM object\n");
>> +
>> +	return 0;
>> +}
>> +
>> +void siw_remove_obj(spinlock_t *lock, struct idr *idr,
>> +		      struct siw_objhdr *hdr)
>> +{
>> +	unsigned long	flags;
>> +
>> +	spin_lock_irqsave(lock, flags);
>> +	idr_remove(idr, hdr->id);
>> +	spin_unlock_irqrestore(lock, flags);
>> +}
>> +
>> +/********** routines to put objs back and free if no ref left
>*****/
>> +
>> +void siw_free_cq(struct kref *ref)
>> +{
>> +	struct siw_cq *cq =
>> +		(container_of(container_of(ref, struct siw_objhdr, ref),
>> +			      struct siw_cq, hdr));
>> +
>> +	siw_dbg_obj(cq, "free cq\n");
>> +
>> +	atomic_dec(&cq->hdr.sdev->num_cq);
>> +	if (cq->queue)
>> +		vfree(cq->queue);
>> +	kfree(cq);
>> +}
>> +
>> +void siw_free_qp(struct kref *ref)
>> +{
>> +	struct siw_qp *qp =
>> +		container_of(container_of(ref, struct siw_objhdr, ref),
>> +			     struct siw_qp, hdr);
>> +	struct siw_device *sdev = qp->hdr.sdev;
>> +	unsigned long flags;
>> +
>> +	siw_dbg_obj(qp, "free qp\n");
>> +
>> +	if (qp->cep)
>> +		siw_cep_put(qp->cep);
>> +
>> +	siw_remove_obj(&sdev->lock, &sdev->qp_idr, &qp->hdr);
>> +
>> +	spin_lock_irqsave(&sdev->lock, flags);
>> +	list_del(&qp->devq);
>> +	spin_unlock_irqrestore(&sdev->lock, flags);
>> +
>> +	if (qp->sendq)
>> +		vfree(qp->sendq);
>> +	if (qp->recvq)
>> +		vfree(qp->recvq);
>> +	if (qp->irq)
>> +		vfree(qp->irq);
>> +	if (qp->orq)
>> +		vfree(qp->orq);
>> +
>> +	siw_put_tx_cpu(qp->tx_cpu);
>> +
>> +	atomic_dec(&sdev->num_qp);
>> +	kfree(qp);
>> +}
>> +
>> +void siw_free_pd(struct kref *ref)
>> +{
>> +	struct siw_pd	*pd =
>> +		container_of(container_of(ref, struct siw_objhdr, ref),
>> +			     struct siw_pd, hdr);
>> +
>> +	siw_dbg_obj(pd, "free PD\n");
>> +
>> +	atomic_dec(&pd->hdr.sdev->num_pd);
>> +}
>> +
>> +void siw_free_mem(struct kref *ref)
>> +{
>> +	struct siw_mem *m;
>> +	struct siw_device *sdev;
>> +
>> +	m = container_of(container_of(ref, struct siw_objhdr, ref),
>> +			 struct siw_mem, hdr);
>> +	sdev = m->hdr.sdev;
>> +
>> +	siw_dbg_obj(m, "free mem\n");
>> +
>> +	atomic_dec(&sdev->num_mr);
>> +
>> +	if (SIW_MEM_IS_MW(m)) {
>> +		struct siw_mw *mw = container_of(m, struct siw_mw, mem);
>> +
>> +		kfree_rcu(mw, rcu);
>> +	} else {
>> +		struct siw_mr *mr = container_of(m, struct siw_mr, mem);
>> +		unsigned long flags;
>> +
>> +		siw_dbg(m->hdr.sdev, "[MEM %d]: has pbl: %s\n",
>> +			OBJ_ID(m), mr->mem.is_pbl ? "y" : "n");
>> +
>> +		if (mr->pd)
>> +			siw_pd_put(mr->pd);
>> +
>> +		if (mr->mem_obj) {
>> +			if (mr->mem.is_pbl == 0)
>> +				siw_umem_release(mr->umem);
>> +			else
>> +				siw_pbl_free(mr->pbl);
>> +
>> +		}
>> +		spin_lock_irqsave(&sdev->lock, flags);
>> +		list_del(&mr->devq);
>> +		spin_unlock_irqrestore(&sdev->lock, flags);
>> +
>> +		kfree_rcu(mr, rcu);
>> +	}
>> +}
>> +
>> +void siw_wqe_put_mem(struct siw_wqe *wqe, enum siw_opcode op)
>> +{
>> +	switch (op) {
>> +
>> +	case SIW_OP_SEND:
>> +	case SIW_OP_WRITE:
>> +	case SIW_OP_SEND_WITH_IMM:
>> +	case SIW_OP_SEND_REMOTE_INV:
>> +	case SIW_OP_READ:
>> +	case SIW_OP_READ_LOCAL_INV:
>> +		if (!(wqe->sqe.flags & SIW_WQE_INLINE))
>> +			siw_unref_mem_sgl(wqe->mem, wqe->sqe.num_sge);
>> +		break;
>> +
>> +	case SIW_OP_RECEIVE:
>> +		siw_unref_mem_sgl(wqe->mem, wqe->rqe.num_sge);
>> +		break;
>> +
>> +	case SIW_OP_READ_RESPONSE:
>> +		siw_unref_mem_sgl(wqe->mem, 1);
>> +		break;
>> +
>> +	default:
>> +		/*
>> +		 * SIW_OP_INVAL_STAG and SIW_OP_REG_MR
>> +		 * do not hold memory references
>> +		 */
>> +		break;
>> +	}
>> +}
>> +
>> +int siw_invalidate_stag(struct siw_pd *pd, u32 stag)
>> +{
>> +	u32 stag_idx = stag >> 8;
>> +	struct siw_mem *mem = siw_mem_id2obj(pd->hdr.sdev, stag_idx);
>> +	int rv = 0;
>> +
>> +	if (unlikely(!mem)) {
>> +		siw_dbg(pd->hdr.sdev, "stag %u unknown\n", stag_idx);
>> +		return -EINVAL;
>> +	}
>> +	if (unlikely(siw_mem2mr(mem)->pd != pd)) {
>> +		siw_dbg(pd->hdr.sdev, "pd mismatch for stag %u\n", stag_idx);
>> +		rv = -EACCES;
>> +		goto out;
>> +	}
>> +	/*
>> +	 * Per RDMA verbs definition, an STag may already be in invalid
>> +	 * state if invalidation is requested. So no state check here.
>> +	 */
>> +	mem->stag_valid = 0;
>> +
>> +	siw_dbg(pd->hdr.sdev, "stag %u now valid\n", stag_idx);
>> +out:
>> +	siw_mem_put(mem);
>> +	return rv;
>> +}
>> diff --git a/drivers/infiniband/sw/siw/siw_obj.h
>b/drivers/infiniband/sw/siw/siw_obj.h
>> new file mode 100644
>> index 000000000000..ed0575c22283
>> --- /dev/null
>> +++ b/drivers/infiniband/sw/siw/siw_obj.h
>> @@ -0,0 +1,226 @@
>> +// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
>> +/*
>> + * Software iWARP device driver
>> + *
>> + * Authors: Bernard Metzler <bmt@zurich.ibm.com>
>> + *
>> + * Copyright (c) 2008-2018, IBM Corporation
>> + *
>> + * 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
>> + * 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.
>> + *
>> + *   - Neither the name of IBM nor the names of its contributors
>may be
>> + *     used to endorse or promote products derived from this
>software without
>> + *     specific prior written permission.
>> + *
>> + * 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.
>> + */
>> +
>> +#ifndef _SIW_OBJ_H
>> +#define _SIW_OBJ_H
>> +
>> +#include <linux/idr.h>
>> +#include <linux/rwsem.h>
>> +#include <linux/version.h>
>> +#include <linux/sched.h>
>> +#include <linux/semaphore.h>
>> +
>> +#include <rdma/ib_verbs.h>
>> +
>> +#include "siw_debug.h"
>> +
>> +extern void siw_free_qp(struct kref *ref);
>> +extern void siw_free_pd(struct kref *ref);
>> +extern void siw_free_cq(struct kref *ref);
>> +extern void siw_free_mem(struct kref *ref);
>> +
>> +static inline struct siw_ucontext *to_siw_ctx(struct ib_ucontext
>*base_ctx)
>> +{
>> +	return container_of(base_ctx, struct siw_ucontext, ib_ucontext);
>> +}
>> +
>> +static inline struct siw_qp *to_siw_qp(struct ib_qp *base_qp)
>> +{
>> +	return container_of(base_qp, struct siw_qp, base_qp);
>> +}
>> +
>> +static inline struct siw_cq *to_siw_cq(struct ib_cq *base_cq)
>> +{
>> +	return container_of(base_cq, struct siw_cq, base_cq);
>> +}
>> +
>> +static inline struct siw_srq *to_siw_srq(struct ib_srq *base_srq)
>> +{
>> +	return container_of(base_srq, struct siw_srq, base_srq);
>> +}
>> +
>> +static inline struct siw_device *to_siw_dev(struct ib_device
>*base_dev)
>> +{
>> +	return container_of(base_dev, struct siw_device, base_dev);
>> +}
>> +
>> +static inline struct siw_mr *to_siw_mr(struct ib_mr *base_mr)
>> +{
>> +	return container_of(base_mr, struct siw_mr, base_mr);
>> +}
>> +
>> +static inline struct siw_pd *to_siw_pd(struct ib_pd *base_pd)
>> +{
>> +	return container_of(base_pd, struct siw_pd, base_pd);
>> +}
>> +
>> +static inline void siw_cq_get(struct siw_cq *cq)
>> +{
>> +	kref_get(&cq->hdr.ref);
>> +	siw_dbg_obj(cq, "new refcount: %d\n", kref_read(&cq->hdr.ref));
>> +}
>> +static inline void siw_qp_get(struct siw_qp *qp)
>> +{
>> +	kref_get(&qp->hdr.ref);
>> +	siw_dbg_obj(qp, "new refcount: %d\n", kref_read(&qp->hdr.ref));
>> +}
>> +
>> +static inline void siw_pd_get(struct siw_pd *pd)
>> +{
>> +	kref_get(&pd->hdr.ref);
>> +	siw_dbg_obj(pd, "new refcount: %d\n", kref_read(&pd->hdr.ref));
>> +}
>> +
>> +static inline void siw_mem_get(struct siw_mem *mem)
>> +{
>> +	kref_get(&mem->hdr.ref);
>> +	siw_dbg_obj(mem, "new refcount: %d\n", kref_read(&mem->hdr.ref));
>> +}
>
>I think that all this kref code is not actually needed and IB/core
>handles it.
>
I tend to agree for other objects than for user communication buffers.
Memory regions must be protected by the provider during in-flight 
access operations such as RDMA Read's or Write's. The memory must not
go away during those operations. I think same is true for associated
objects like QP and PD - and it is cheaper to bump up a ref counter
compared to taking locks.
I agree, there is potential for simplification. I would like to have
a closer look when the rdma core has been reshaped to explicitly
control the lifetime of all other objects - as it is now already
doing for PD's.
Leon Romanovsky Feb. 27, 2019, 12:47 p.m. UTC | #3 
On Wed, Feb 27, 2019 at 12:06:49PM +0000, Bernard Metzler wrote:
> -----"Leon Romanovsky" <leon@kernel.org> wrote: -----
>
> >To: "Bernard Metzler" <bmt@zurich.ibm.com>
> >From: "Leon Romanovsky" <leon@kernel.org>
> >Date: 02/24/2019 02:17PM
> >Cc: linux-rdma@vger.kernel.org
> >Subject: Re: [PATCH v5 04/13] SIW object management
> >
> >On Tue, Feb 19, 2019 at 11:08:54AM +0100, Bernard Metzler wrote:
> >> Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
> >> ---
> >>  drivers/infiniband/sw/siw/siw_obj.c | 341
> >++++++++++++++++++++++++++++
> >>  drivers/infiniband/sw/siw/siw_obj.h | 226 ++++++++++++++++++
> >>  2 files changed, 567 insertions(+)
> >>  create mode 100644 drivers/infiniband/sw/siw/siw_obj.c
> >>  create mode 100644 drivers/infiniband/sw/siw/siw_obj.h
> >>
> >> diff --git a/drivers/infiniband/sw/siw/siw_obj.c
> >b/drivers/infiniband/sw/siw/siw_obj.c
> >> new file mode 100644
> >> index 000000000000..a086a3c9aca7
> >> --- /dev/null
> >> +++ b/drivers/infiniband/sw/siw/siw_obj.c
> >> @@ -0,0 +1,341 @@
> >> +// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
> >> +/*
> >> + * Software iWARP device driver
> >> + *
> >> + * Authors: Bernard Metzler <bmt@zurich.ibm.com>
> >> + *
> >> + * Copyright (c) 2008-2018, IBM Corporation
> >> + *
> >> + * 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
> >> + * 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.
> >> + *
> >> + *   - Neither the name of IBM nor the names of its contributors
> >may be
> >> + *     used to endorse or promote products derived from this
> >software without
> >> + *     specific prior written permission.
> >> + *
> >> + * 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 <linux/spinlock.h>
> >> +#include <linux/kref.h>
> >> +#include <linux/vmalloc.h>
> >> +
> >> +#include "siw.h"
> >> +#include "siw_obj.h"
> >> +#include "siw_cm.h"
> >> +
> >> +void siw_objhdr_init(struct siw_objhdr *hdr)
> >> +{
> >> +	kref_init(&hdr->ref);
> >> +}
> >> +
> >> +void siw_idr_init(struct siw_device *sdev)
> >> +{
> >> +	spin_lock_init(&sdev->lock);
> >> +
> >> +	idr_init(&sdev->qp_idr);
> >> +	idr_init(&sdev->cq_idr);
> >> +	idr_init(&sdev->pd_idr);
> >> +	idr_init(&sdev->mem_idr);
> >> +}
> >> +
> >> +void siw_idr_release(struct siw_device *sdev)
> >> +{
> >> +	idr_destroy(&sdev->qp_idr);
> >> +	idr_destroy(&sdev->cq_idr);
> >> +	idr_destroy(&sdev->pd_idr);
> >> +	idr_destroy(&sdev->mem_idr);
> >> +}
> >> +
> >> +static int siw_add_obj(spinlock_t *lock, struct idr *idr,
> >> +		       struct siw_objhdr *obj)
> >> +{
> >> +	unsigned long flags;
> >> +	int id, min_id;
> >> +
> >> +	get_random_bytes(&min_id, 4);
> >> +	min_id &= 0x00FFFFFF;
> >> +again:
> >> +	spin_lock_irqsave(lock, flags);
> >> +	id = idr_alloc(idr, obj, min_id, 0x00FFFFFF - 1, GFP_KERNEL);
> >> +	spin_unlock_irqrestore(lock, flags);
> >> +
> >> +	if (id > 0) {
> >> +		siw_objhdr_init(obj);
> >> +		obj->id = id;
> >> +	} else if (id == -ENOSPC && min_id != 1) {
> >> +		min_id = 1;
> >> +		goto again;
> >> +	} else {
> >> +		pr_warn("SIW: object ID space\n");
> >> +	}
> >> +	if (id > 0)
> >> +		return 0;
> >> +
> >> +	return id == 0 ? -ENOSPC : id;
> >> +}
> >> +
> >> +int siw_qp_add(struct siw_device *sdev, struct siw_qp *qp)
> >> +{
> >> +	int rv = siw_add_obj(&sdev->lock, &sdev->qp_idr, &qp->hdr);
> >> +
> >> +	if (!rv) {
> >> +		qp->hdr.sdev = sdev;
> >> +		siw_dbg_obj(qp, "new QP\n");
> >> +	}
> >> +	return rv;
> >> +}
> >> +
> >> +int siw_cq_add(struct siw_device *sdev, struct siw_cq *cq)
> >> +{
> >> +	int rv = siw_add_obj(&sdev->lock, &sdev->cq_idr, &cq->hdr);
> >> +
> >> +	if (!rv) {
> >> +		cq->hdr.sdev = sdev;
> >> +		siw_dbg_obj(cq, "new CQ\n");
> >> +	}
> >> +	return rv;
> >> +}
> >> +
> >> +int siw_pd_add(struct siw_device *sdev, struct siw_pd *pd)
> >> +{
> >> +	int rv = siw_add_obj(&sdev->lock, &sdev->pd_idr, &pd->hdr);
> >> +
> >> +	if (!rv) {
> >> +		pd->hdr.sdev = sdev;
> >> +		siw_dbg_obj(pd, "new PD\n");
> >> +	}
> >> +	return rv;
> >> +}
> >> +
> >> +/*
> >> + * Stag lookup is based on its index part only (24 bits).
> >> + * The code avoids special Stag of zero and tries to randomize
> >> + * STag values between 1 and SIW_STAG_MAX_INDEX.
> >> + */
> >> +int siw_mem_add(struct siw_device *sdev, struct siw_mem *m)
> >> +{
> >> +	unsigned long flags;
> >> +	int id, min_id, max_id = 0x00FFFFFF;
> >> +
> >> +	do {
> >> +		get_random_bytes(&min_id, 4);
> >> +		min_id &= 0x00FFFFFF;
> >> +	} while (min_id <= 0);
> >> +again:
> >> +	spin_lock_irqsave(&sdev->lock, flags);
> >> +	id = idr_alloc(&sdev->mem_idr, m, min_id, max_id, GFP_KERNEL);
> >> +	spin_unlock_irqrestore(&sdev->lock, flags);
> >> +
> >> +	if (id == -ENOMEM)
> >> +		return -ENOMEM;
> >> +
> >> +	if (id == -ENOSPC) {
> >> +		max_id = min_id;
> >> +		min_id /= 2;
> >> +		if (min_id <= 0) {
> >> +			pr_warn("SIW: memory ID space\n");
> >> +			return -ENOSPC;
> >> +		}
> >> +		goto again;
> >> +	}
> >> +	siw_objhdr_init(&m->hdr);
> >> +	m->hdr.id = id;
> >> +	m->hdr.sdev = sdev;
> >> +
> >> +	siw_dbg_obj(m, "new MEM object\n");
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +void siw_remove_obj(spinlock_t *lock, struct idr *idr,
> >> +		      struct siw_objhdr *hdr)
> >> +{
> >> +	unsigned long	flags;
> >> +
> >> +	spin_lock_irqsave(lock, flags);
> >> +	idr_remove(idr, hdr->id);
> >> +	spin_unlock_irqrestore(lock, flags);
> >> +}
> >> +
> >> +/********** routines to put objs back and free if no ref left
> >*****/
> >> +
> >> +void siw_free_cq(struct kref *ref)
> >> +{
> >> +	struct siw_cq *cq =
> >> +		(container_of(container_of(ref, struct siw_objhdr, ref),
> >> +			      struct siw_cq, hdr));
> >> +
> >> +	siw_dbg_obj(cq, "free cq\n");
> >> +
> >> +	atomic_dec(&cq->hdr.sdev->num_cq);
> >> +	if (cq->queue)
> >> +		vfree(cq->queue);
> >> +	kfree(cq);
> >> +}
> >> +
> >> +void siw_free_qp(struct kref *ref)
> >> +{
> >> +	struct siw_qp *qp =
> >> +		container_of(container_of(ref, struct siw_objhdr, ref),
> >> +			     struct siw_qp, hdr);
> >> +	struct siw_device *sdev = qp->hdr.sdev;
> >> +	unsigned long flags;
> >> +
> >> +	siw_dbg_obj(qp, "free qp\n");
> >> +
> >> +	if (qp->cep)
> >> +		siw_cep_put(qp->cep);
> >> +
> >> +	siw_remove_obj(&sdev->lock, &sdev->qp_idr, &qp->hdr);
> >> +
> >> +	spin_lock_irqsave(&sdev->lock, flags);
> >> +	list_del(&qp->devq);
> >> +	spin_unlock_irqrestore(&sdev->lock, flags);
> >> +
> >> +	if (qp->sendq)
> >> +		vfree(qp->sendq);
> >> +	if (qp->recvq)
> >> +		vfree(qp->recvq);
> >> +	if (qp->irq)
> >> +		vfree(qp->irq);
> >> +	if (qp->orq)
> >> +		vfree(qp->orq);
> >> +
> >> +	siw_put_tx_cpu(qp->tx_cpu);
> >> +
> >> +	atomic_dec(&sdev->num_qp);
> >> +	kfree(qp);
> >> +}
> >> +
> >> +void siw_free_pd(struct kref *ref)
> >> +{
> >> +	struct siw_pd	*pd =
> >> +		container_of(container_of(ref, struct siw_objhdr, ref),
> >> +			     struct siw_pd, hdr);
> >> +
> >> +	siw_dbg_obj(pd, "free PD\n");
> >> +
> >> +	atomic_dec(&pd->hdr.sdev->num_pd);
> >> +}
> >> +
> >> +void siw_free_mem(struct kref *ref)
> >> +{
> >> +	struct siw_mem *m;
> >> +	struct siw_device *sdev;
> >> +
> >> +	m = container_of(container_of(ref, struct siw_objhdr, ref),
> >> +			 struct siw_mem, hdr);
> >> +	sdev = m->hdr.sdev;
> >> +
> >> +	siw_dbg_obj(m, "free mem\n");
> >> +
> >> +	atomic_dec(&sdev->num_mr);
> >> +
> >> +	if (SIW_MEM_IS_MW(m)) {
> >> +		struct siw_mw *mw = container_of(m, struct siw_mw, mem);
> >> +
> >> +		kfree_rcu(mw, rcu);
> >> +	} else {
> >> +		struct siw_mr *mr = container_of(m, struct siw_mr, mem);
> >> +		unsigned long flags;
> >> +
> >> +		siw_dbg(m->hdr.sdev, "[MEM %d]: has pbl: %s\n",
> >> +			OBJ_ID(m), mr->mem.is_pbl ? "y" : "n");
> >> +
> >> +		if (mr->pd)
> >> +			siw_pd_put(mr->pd);
> >> +
> >> +		if (mr->mem_obj) {
> >> +			if (mr->mem.is_pbl == 0)
> >> +				siw_umem_release(mr->umem);
> >> +			else
> >> +				siw_pbl_free(mr->pbl);
> >> +
> >> +		}
> >> +		spin_lock_irqsave(&sdev->lock, flags);
> >> +		list_del(&mr->devq);
> >> +		spin_unlock_irqrestore(&sdev->lock, flags);
> >> +
> >> +		kfree_rcu(mr, rcu);
> >> +	}
> >> +}
> >> +
> >> +void siw_wqe_put_mem(struct siw_wqe *wqe, enum siw_opcode op)
> >> +{
> >> +	switch (op) {
> >> +
> >> +	case SIW_OP_SEND:
> >> +	case SIW_OP_WRITE:
> >> +	case SIW_OP_SEND_WITH_IMM:
> >> +	case SIW_OP_SEND_REMOTE_INV:
> >> +	case SIW_OP_READ:
> >> +	case SIW_OP_READ_LOCAL_INV:
> >> +		if (!(wqe->sqe.flags & SIW_WQE_INLINE))
> >> +			siw_unref_mem_sgl(wqe->mem, wqe->sqe.num_sge);
> >> +		break;
> >> +
> >> +	case SIW_OP_RECEIVE:
> >> +		siw_unref_mem_sgl(wqe->mem, wqe->rqe.num_sge);
> >> +		break;
> >> +
> >> +	case SIW_OP_READ_RESPONSE:
> >> +		siw_unref_mem_sgl(wqe->mem, 1);
> >> +		break;
> >> +
> >> +	default:
> >> +		/*
> >> +		 * SIW_OP_INVAL_STAG and SIW_OP_REG_MR
> >> +		 * do not hold memory references
> >> +		 */
> >> +		break;
> >> +	}
> >> +}
> >> +
> >> +int siw_invalidate_stag(struct siw_pd *pd, u32 stag)
> >> +{
> >> +	u32 stag_idx = stag >> 8;
> >> +	struct siw_mem *mem = siw_mem_id2obj(pd->hdr.sdev, stag_idx);
> >> +	int rv = 0;
> >> +
> >> +	if (unlikely(!mem)) {
> >> +		siw_dbg(pd->hdr.sdev, "stag %u unknown\n", stag_idx);
> >> +		return -EINVAL;
> >> +	}
> >> +	if (unlikely(siw_mem2mr(mem)->pd != pd)) {
> >> +		siw_dbg(pd->hdr.sdev, "pd mismatch for stag %u\n", stag_idx);
> >> +		rv = -EACCES;
> >> +		goto out;
> >> +	}
> >> +	/*
> >> +	 * Per RDMA verbs definition, an STag may already be in invalid
> >> +	 * state if invalidation is requested. So no state check here.
> >> +	 */
> >> +	mem->stag_valid = 0;
> >> +
> >> +	siw_dbg(pd->hdr.sdev, "stag %u now valid\n", stag_idx);
> >> +out:
> >> +	siw_mem_put(mem);
> >> +	return rv;
> >> +}
> >> diff --git a/drivers/infiniband/sw/siw/siw_obj.h
> >b/drivers/infiniband/sw/siw/siw_obj.h
> >> new file mode 100644
> >> index 000000000000..ed0575c22283
> >> --- /dev/null
> >> +++ b/drivers/infiniband/sw/siw/siw_obj.h
> >> @@ -0,0 +1,226 @@
> >> +// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
> >> +/*
> >> + * Software iWARP device driver
> >> + *
> >> + * Authors: Bernard Metzler <bmt@zurich.ibm.com>
> >> + *
> >> + * Copyright (c) 2008-2018, IBM Corporation
> >> + *
> >> + * 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
> >> + * 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.
> >> + *
> >> + *   - Neither the name of IBM nor the names of its contributors
> >may be
> >> + *     used to endorse or promote products derived from this
> >software without
> >> + *     specific prior written permission.
> >> + *
> >> + * 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.
> >> + */
> >> +
> >> +#ifndef _SIW_OBJ_H
> >> +#define _SIW_OBJ_H
> >> +
> >> +#include <linux/idr.h>
> >> +#include <linux/rwsem.h>
> >> +#include <linux/version.h>
> >> +#include <linux/sched.h>
> >> +#include <linux/semaphore.h>
> >> +
> >> +#include <rdma/ib_verbs.h>
> >> +
> >> +#include "siw_debug.h"
> >> +
> >> +extern void siw_free_qp(struct kref *ref);
> >> +extern void siw_free_pd(struct kref *ref);
> >> +extern void siw_free_cq(struct kref *ref);
> >> +extern void siw_free_mem(struct kref *ref);
> >> +
> >> +static inline struct siw_ucontext *to_siw_ctx(struct ib_ucontext
> >*base_ctx)
> >> +{
> >> +	return container_of(base_ctx, struct siw_ucontext, ib_ucontext);
> >> +}
> >> +
> >> +static inline struct siw_qp *to_siw_qp(struct ib_qp *base_qp)
> >> +{
> >> +	return container_of(base_qp, struct siw_qp, base_qp);
> >> +}
> >> +
> >> +static inline struct siw_cq *to_siw_cq(struct ib_cq *base_cq)
> >> +{
> >> +	return container_of(base_cq, struct siw_cq, base_cq);
> >> +}
> >> +
> >> +static inline struct siw_srq *to_siw_srq(struct ib_srq *base_srq)
> >> +{
> >> +	return container_of(base_srq, struct siw_srq, base_srq);
> >> +}
> >> +
> >> +static inline struct siw_device *to_siw_dev(struct ib_device
> >*base_dev)
> >> +{
> >> +	return container_of(base_dev, struct siw_device, base_dev);
> >> +}
> >> +
> >> +static inline struct siw_mr *to_siw_mr(struct ib_mr *base_mr)
> >> +{
> >> +	return container_of(base_mr, struct siw_mr, base_mr);
> >> +}
> >> +
> >> +static inline struct siw_pd *to_siw_pd(struct ib_pd *base_pd)
> >> +{
> >> +	return container_of(base_pd, struct siw_pd, base_pd);
> >> +}
> >> +
> >> +static inline void siw_cq_get(struct siw_cq *cq)
> >> +{
> >> +	kref_get(&cq->hdr.ref);
> >> +	siw_dbg_obj(cq, "new refcount: %d\n", kref_read(&cq->hdr.ref));
> >> +}
> >> +static inline void siw_qp_get(struct siw_qp *qp)
> >> +{
> >> +	kref_get(&qp->hdr.ref);
> >> +	siw_dbg_obj(qp, "new refcount: %d\n", kref_read(&qp->hdr.ref));
> >> +}
> >> +
> >> +static inline void siw_pd_get(struct siw_pd *pd)
> >> +{
> >> +	kref_get(&pd->hdr.ref);
> >> +	siw_dbg_obj(pd, "new refcount: %d\n", kref_read(&pd->hdr.ref));
> >> +}
> >> +
> >> +static inline void siw_mem_get(struct siw_mem *mem)
> >> +{
> >> +	kref_get(&mem->hdr.ref);
> >> +	siw_dbg_obj(mem, "new refcount: %d\n", kref_read(&mem->hdr.ref));
> >> +}
> >
> >I think that all this kref code is not actually needed and IB/core
> >handles it.
> >
> I tend to agree for other objects than for user communication buffers.
> Memory regions must be protected by the provider during in-flight
> access operations such as RDMA Read's or Write's. The memory must not
> go away during those operations. I think same is true for associated
> objects like QP and PD - and it is cheaper to bump up a ref counter
> compared to taking locks.
> I agree, there is potential for simplification. I would like to have
> a closer look when the rdma core has been reshaped to explicitly
> control the lifetime of all other objects - as it is now already
> doing for PD's.

IB/core manages lifetime for all objects, the difference between PD and
other objects in who allocates/free such memory.

From my experience of converting allocations, badly put kref is worse
than absence of it.

Thanks

>
Jason Gunthorpe March 8, 2019, 1:26 p.m. UTC | #4 
On Tue, Feb 19, 2019 at 11:08:54AM +0100, Bernard Metzler wrote:
> +
> +static inline void siw_pd_put(struct siw_pd *pd)
> +{
> +	siw_dbg_obj(pd, "old refcount: %d\n", kref_read(&pd->hdr.ref));
> +	kref_put(&pd->hdr.ref, siw_free_pd);
> +}
> +
> +/*
> + * siw_mem_id2obj()
> + *
> + * resolves memory from stag given by id. might be called from:
> + * o process context before sending out of sgl, or
> + * o in softirq when resolving target memory
> + */
> +static inline struct siw_mem *siw_mem_id2obj(struct siw_device *sdev, int id)
> +{
> +	struct siw_objhdr *obj;
> +	struct siw_mem *mem = NULL;
> +
> +	rcu_read_lock();
> +	obj = siw_get_obj(&sdev->mem_idr, id);
> +	rcu_read_unlock();

There is something wrong with this use of rcu:

 rcu_read_lock();
 struct siw_objhdr *obj = idr_find(idr, id);
 if (obj)
 		kref_get(&obj->ref);


1) Not a good idea to split locking and lookup, one function should
   handle both:

  rcu_read_lock()
  obj = __xa_load(xa, id);

2) It is racy, obj may have have gone to siw_free_mem -> kfree_rcu and
   now has a 0 ref, this will caus kref_get to warn_on.

    if (obj)
      if (!kref_get_unless_zero(&obj->ref))
           obj = NULL

Jason
diff mbox series

Patch

diff --git a/drivers/infiniband/sw/siw/siw_obj.c b/drivers/infiniband/sw/siw/siw_obj.c
new file mode 100644
index 000000000000..a086a3c9aca7
--- /dev/null
+++ b/drivers/infiniband/sw/siw/siw_obj.c
@@ -0,0 +1,341 @@ 
+// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
+/*
+ * Software iWARP device driver
+ *
+ * Authors: Bernard Metzler <bmt@zurich.ibm.com>
+ *
+ * Copyright (c) 2008-2018, IBM Corporation
+ *
+ * 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
+ * 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.
+ *
+ *   - Neither the name of IBM nor the names of its contributors may be
+ *     used to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * 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 <linux/spinlock.h>
+#include <linux/kref.h>
+#include <linux/vmalloc.h>
+
+#include "siw.h"
+#include "siw_obj.h"
+#include "siw_cm.h"
+
+void siw_objhdr_init(struct siw_objhdr *hdr)
+{
+	kref_init(&hdr->ref);
+}
+
+void siw_idr_init(struct siw_device *sdev)
+{
+	spin_lock_init(&sdev->lock);
+
+	idr_init(&sdev->qp_idr);
+	idr_init(&sdev->cq_idr);
+	idr_init(&sdev->pd_idr);
+	idr_init(&sdev->mem_idr);
+}
+
+void siw_idr_release(struct siw_device *sdev)
+{
+	idr_destroy(&sdev->qp_idr);
+	idr_destroy(&sdev->cq_idr);
+	idr_destroy(&sdev->pd_idr);
+	idr_destroy(&sdev->mem_idr);
+}
+
+static int siw_add_obj(spinlock_t *lock, struct idr *idr,
+		       struct siw_objhdr *obj)
+{
+	unsigned long flags;
+	int id, min_id;
+
+	get_random_bytes(&min_id, 4);
+	min_id &= 0x00FFFFFF;
+again:
+	spin_lock_irqsave(lock, flags);
+	id = idr_alloc(idr, obj, min_id, 0x00FFFFFF - 1, GFP_KERNEL);
+	spin_unlock_irqrestore(lock, flags);
+
+	if (id > 0) {
+		siw_objhdr_init(obj);
+		obj->id = id;
+	} else if (id == -ENOSPC && min_id != 1) {
+		min_id = 1;
+		goto again;
+	} else {
+		pr_warn("SIW: object ID space\n");
+	}
+	if (id > 0)
+		return 0;
+
+	return id == 0 ? -ENOSPC : id;
+}
+
+int siw_qp_add(struct siw_device *sdev, struct siw_qp *qp)
+{
+	int rv = siw_add_obj(&sdev->lock, &sdev->qp_idr, &qp->hdr);
+
+	if (!rv) {
+		qp->hdr.sdev = sdev;
+		siw_dbg_obj(qp, "new QP\n");
+	}
+	return rv;
+}
+
+int siw_cq_add(struct siw_device *sdev, struct siw_cq *cq)
+{
+	int rv = siw_add_obj(&sdev->lock, &sdev->cq_idr, &cq->hdr);
+
+	if (!rv) {
+		cq->hdr.sdev = sdev;
+		siw_dbg_obj(cq, "new CQ\n");
+	}
+	return rv;
+}
+
+int siw_pd_add(struct siw_device *sdev, struct siw_pd *pd)
+{
+	int rv = siw_add_obj(&sdev->lock, &sdev->pd_idr, &pd->hdr);
+
+	if (!rv) {
+		pd->hdr.sdev = sdev;
+		siw_dbg_obj(pd, "new PD\n");
+	}
+	return rv;
+}
+
+/*
+ * Stag lookup is based on its index part only (24 bits).
+ * The code avoids special Stag of zero and tries to randomize
+ * STag values between 1 and SIW_STAG_MAX_INDEX.
+ */
+int siw_mem_add(struct siw_device *sdev, struct siw_mem *m)
+{
+	unsigned long flags;
+	int id, min_id, max_id = 0x00FFFFFF;
+
+	do {
+		get_random_bytes(&min_id, 4);
+		min_id &= 0x00FFFFFF;
+	} while (min_id <= 0);
+again:
+	spin_lock_irqsave(&sdev->lock, flags);
+	id = idr_alloc(&sdev->mem_idr, m, min_id, max_id, GFP_KERNEL);
+	spin_unlock_irqrestore(&sdev->lock, flags);
+
+	if (id == -ENOMEM)
+		return -ENOMEM;
+
+	if (id == -ENOSPC) {
+		max_id = min_id;
+		min_id /= 2;
+		if (min_id <= 0) {
+			pr_warn("SIW: memory ID space\n");
+			return -ENOSPC;
+		}
+		goto again;
+	}
+	siw_objhdr_init(&m->hdr);
+	m->hdr.id = id;
+	m->hdr.sdev = sdev;
+
+	siw_dbg_obj(m, "new MEM object\n");
+
+	return 0;
+}
+
+void siw_remove_obj(spinlock_t *lock, struct idr *idr,
+		      struct siw_objhdr *hdr)
+{
+	unsigned long	flags;
+
+	spin_lock_irqsave(lock, flags);
+	idr_remove(idr, hdr->id);
+	spin_unlock_irqrestore(lock, flags);
+}
+
+/********** routines to put objs back and free if no ref left *****/
+
+void siw_free_cq(struct kref *ref)
+{
+	struct siw_cq *cq =
+		(container_of(container_of(ref, struct siw_objhdr, ref),
+			      struct siw_cq, hdr));
+
+	siw_dbg_obj(cq, "free cq\n");
+
+	atomic_dec(&cq->hdr.sdev->num_cq);
+	if (cq->queue)
+		vfree(cq->queue);
+	kfree(cq);
+}
+
+void siw_free_qp(struct kref *ref)
+{
+	struct siw_qp *qp =
+		container_of(container_of(ref, struct siw_objhdr, ref),
+			     struct siw_qp, hdr);
+	struct siw_device *sdev = qp->hdr.sdev;
+	unsigned long flags;
+
+	siw_dbg_obj(qp, "free qp\n");
+
+	if (qp->cep)
+		siw_cep_put(qp->cep);
+
+	siw_remove_obj(&sdev->lock, &sdev->qp_idr, &qp->hdr);
+
+	spin_lock_irqsave(&sdev->lock, flags);
+	list_del(&qp->devq);
+	spin_unlock_irqrestore(&sdev->lock, flags);
+
+	if (qp->sendq)
+		vfree(qp->sendq);
+	if (qp->recvq)
+		vfree(qp->recvq);
+	if (qp->irq)
+		vfree(qp->irq);
+	if (qp->orq)
+		vfree(qp->orq);
+
+	siw_put_tx_cpu(qp->tx_cpu);
+
+	atomic_dec(&sdev->num_qp);
+	kfree(qp);
+}
+
+void siw_free_pd(struct kref *ref)
+{
+	struct siw_pd	*pd =
+		container_of(container_of(ref, struct siw_objhdr, ref),
+			     struct siw_pd, hdr);
+
+	siw_dbg_obj(pd, "free PD\n");
+
+	atomic_dec(&pd->hdr.sdev->num_pd);
+}
+
+void siw_free_mem(struct kref *ref)
+{
+	struct siw_mem *m;
+	struct siw_device *sdev;
+
+	m = container_of(container_of(ref, struct siw_objhdr, ref),
+			 struct siw_mem, hdr);
+	sdev = m->hdr.sdev;
+
+	siw_dbg_obj(m, "free mem\n");
+
+	atomic_dec(&sdev->num_mr);
+
+	if (SIW_MEM_IS_MW(m)) {
+		struct siw_mw *mw = container_of(m, struct siw_mw, mem);
+
+		kfree_rcu(mw, rcu);
+	} else {
+		struct siw_mr *mr = container_of(m, struct siw_mr, mem);
+		unsigned long flags;
+
+		siw_dbg(m->hdr.sdev, "[MEM %d]: has pbl: %s\n",
+			OBJ_ID(m), mr->mem.is_pbl ? "y" : "n");
+
+		if (mr->pd)
+			siw_pd_put(mr->pd);
+
+		if (mr->mem_obj) {
+			if (mr->mem.is_pbl == 0)
+				siw_umem_release(mr->umem);
+			else
+				siw_pbl_free(mr->pbl);
+
+		}
+		spin_lock_irqsave(&sdev->lock, flags);
+		list_del(&mr->devq);
+		spin_unlock_irqrestore(&sdev->lock, flags);
+
+		kfree_rcu(mr, rcu);
+	}
+}
+
+void siw_wqe_put_mem(struct siw_wqe *wqe, enum siw_opcode op)
+{
+	switch (op) {
+
+	case SIW_OP_SEND:
+	case SIW_OP_WRITE:
+	case SIW_OP_SEND_WITH_IMM:
+	case SIW_OP_SEND_REMOTE_INV:
+	case SIW_OP_READ:
+	case SIW_OP_READ_LOCAL_INV:
+		if (!(wqe->sqe.flags & SIW_WQE_INLINE))
+			siw_unref_mem_sgl(wqe->mem, wqe->sqe.num_sge);
+		break;
+
+	case SIW_OP_RECEIVE:
+		siw_unref_mem_sgl(wqe->mem, wqe->rqe.num_sge);
+		break;
+
+	case SIW_OP_READ_RESPONSE:
+		siw_unref_mem_sgl(wqe->mem, 1);
+		break;
+
+	default:
+		/*
+		 * SIW_OP_INVAL_STAG and SIW_OP_REG_MR
+		 * do not hold memory references
+		 */
+		break;
+	}
+}
+
+int siw_invalidate_stag(struct siw_pd *pd, u32 stag)
+{
+	u32 stag_idx = stag >> 8;
+	struct siw_mem *mem = siw_mem_id2obj(pd->hdr.sdev, stag_idx);
+	int rv = 0;
+
+	if (unlikely(!mem)) {
+		siw_dbg(pd->hdr.sdev, "stag %u unknown\n", stag_idx);
+		return -EINVAL;
+	}
+	if (unlikely(siw_mem2mr(mem)->pd != pd)) {
+		siw_dbg(pd->hdr.sdev, "pd mismatch for stag %u\n", stag_idx);
+		rv = -EACCES;
+		goto out;
+	}
+	/*
+	 * Per RDMA verbs definition, an STag may already be in invalid
+	 * state if invalidation is requested. So no state check here.
+	 */
+	mem->stag_valid = 0;
+
+	siw_dbg(pd->hdr.sdev, "stag %u now valid\n", stag_idx);
+out:
+	siw_mem_put(mem);
+	return rv;
+}
diff --git a/drivers/infiniband/sw/siw/siw_obj.h b/drivers/infiniband/sw/siw/siw_obj.h
new file mode 100644
index 000000000000..ed0575c22283
--- /dev/null
+++ b/drivers/infiniband/sw/siw/siw_obj.h
@@ -0,0 +1,226 @@ 
+// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
+/*
+ * Software iWARP device driver
+ *
+ * Authors: Bernard Metzler <bmt@zurich.ibm.com>
+ *
+ * Copyright (c) 2008-2018, IBM Corporation
+ *
+ * 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
+ * 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.
+ *
+ *   - Neither the name of IBM nor the names of its contributors may be
+ *     used to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * 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.
+ */
+
+#ifndef _SIW_OBJ_H
+#define _SIW_OBJ_H
+
+#include <linux/idr.h>
+#include <linux/rwsem.h>
+#include <linux/version.h>
+#include <linux/sched.h>
+#include <linux/semaphore.h>
+
+#include <rdma/ib_verbs.h>
+
+#include "siw_debug.h"
+
+extern void siw_free_qp(struct kref *ref);
+extern void siw_free_pd(struct kref *ref);
+extern void siw_free_cq(struct kref *ref);
+extern void siw_free_mem(struct kref *ref);
+
+static inline struct siw_ucontext *to_siw_ctx(struct ib_ucontext *base_ctx)
+{
+	return container_of(base_ctx, struct siw_ucontext, ib_ucontext);
+}
+
+static inline struct siw_qp *to_siw_qp(struct ib_qp *base_qp)
+{
+	return container_of(base_qp, struct siw_qp, base_qp);
+}
+
+static inline struct siw_cq *to_siw_cq(struct ib_cq *base_cq)
+{
+	return container_of(base_cq, struct siw_cq, base_cq);
+}
+
+static inline struct siw_srq *to_siw_srq(struct ib_srq *base_srq)
+{
+	return container_of(base_srq, struct siw_srq, base_srq);
+}
+
+static inline struct siw_device *to_siw_dev(struct ib_device *base_dev)
+{
+	return container_of(base_dev, struct siw_device, base_dev);
+}
+
+static inline struct siw_mr *to_siw_mr(struct ib_mr *base_mr)
+{
+	return container_of(base_mr, struct siw_mr, base_mr);
+}
+
+static inline struct siw_pd *to_siw_pd(struct ib_pd *base_pd)
+{
+	return container_of(base_pd, struct siw_pd, base_pd);
+}
+
+static inline void siw_cq_get(struct siw_cq *cq)
+{
+	kref_get(&cq->hdr.ref);
+	siw_dbg_obj(cq, "new refcount: %d\n", kref_read(&cq->hdr.ref));
+}
+static inline void siw_qp_get(struct siw_qp *qp)
+{
+	kref_get(&qp->hdr.ref);
+	siw_dbg_obj(qp, "new refcount: %d\n", kref_read(&qp->hdr.ref));
+}
+
+static inline void siw_pd_get(struct siw_pd *pd)
+{
+	kref_get(&pd->hdr.ref);
+	siw_dbg_obj(pd, "new refcount: %d\n", kref_read(&pd->hdr.ref));
+}
+
+static inline void siw_mem_get(struct siw_mem *mem)
+{
+	kref_get(&mem->hdr.ref);
+	siw_dbg_obj(mem, "new refcount: %d\n", kref_read(&mem->hdr.ref));
+}
+
+static inline void siw_mem_put(struct siw_mem *mem)
+{
+	siw_dbg_obj(mem, "old refcount: %d\n", kref_read(&mem->hdr.ref));
+	kref_put(&mem->hdr.ref, siw_free_mem);
+}
+
+static inline void siw_unref_mem_sgl(struct siw_mem **mem,
+				     unsigned int num_sge)
+{
+	while (num_sge) {
+		if (*mem == NULL)
+			break;
+
+		siw_mem_put(*mem);
+		*mem = NULL;
+		mem++; num_sge--;
+	}
+}
+
+static inline struct siw_objhdr *siw_get_obj(struct idr *idr, int id)
+{
+	struct siw_objhdr *obj = idr_find(idr, id);
+
+	if (obj)
+		kref_get(&obj->ref);
+
+	return obj;
+}
+
+static inline struct siw_cq *siw_cq_id2obj(struct siw_device *sdev, int id)
+{
+	struct siw_objhdr *obj = siw_get_obj(&sdev->cq_idr, id);
+
+	if (obj)
+		return container_of(obj, struct siw_cq, hdr);
+
+	return NULL;
+}
+
+static inline struct siw_qp *siw_qp_id2obj(struct siw_device *sdev, int id)
+{
+	struct siw_objhdr *obj = siw_get_obj(&sdev->qp_idr, id);
+
+	if (obj)
+		return container_of(obj, struct siw_qp, hdr);
+
+	return NULL;
+}
+
+static inline void siw_cq_put(struct siw_cq *cq)
+{
+	siw_dbg_obj(cq, "old refcount: %d\n", kref_read(&cq->hdr.ref));
+	kref_put(&cq->hdr.ref, siw_free_cq);
+}
+
+static inline void siw_qp_put(struct siw_qp *qp)
+{
+	siw_dbg_obj(qp, "old refcount: %d\n", kref_read(&qp->hdr.ref));
+	kref_put(&qp->hdr.ref, siw_free_qp);
+}
+
+static inline void siw_pd_put(struct siw_pd *pd)
+{
+	siw_dbg_obj(pd, "old refcount: %d\n", kref_read(&pd->hdr.ref));
+	kref_put(&pd->hdr.ref, siw_free_pd);
+}
+
+/*
+ * siw_mem_id2obj()
+ *
+ * resolves memory from stag given by id. might be called from:
+ * o process context before sending out of sgl, or
+ * o in softirq when resolving target memory
+ */
+static inline struct siw_mem *siw_mem_id2obj(struct siw_device *sdev, int id)
+{
+	struct siw_objhdr *obj;
+	struct siw_mem *mem = NULL;
+
+	rcu_read_lock();
+	obj = siw_get_obj(&sdev->mem_idr, id);
+	rcu_read_unlock();
+
+	if (likely(obj)) {
+		mem = container_of(obj, struct siw_mem, hdr);
+		siw_dbg_obj(mem, "new refcount: %d\n",
+			    kref_read(&obj->ref));
+	}
+	return mem;
+}
+
+extern void siw_remove_obj(spinlock_t *lock, struct idr *idr,
+				struct siw_objhdr *hdr);
+
+extern void siw_objhdr_init(struct siw_objhdr *hdr);
+extern void siw_idr_init(struct siw_device *dev);
+extern void siw_idr_release(struct siw_device *dev);
+
+extern struct siw_cq *siw_cq_id2obj(struct siw_device *dev, int id);
+extern struct siw_qp *siw_qp_id2obj(struct siw_device *dev, int id);
+extern struct siw_mem *siw_mem_id2obj(struct siw_device *dev, int id);
+
+extern int siw_qp_add(struct siw_device *dev, struct siw_qp *qp);
+extern int siw_cq_add(struct siw_device *dev, struct siw_cq *cq);
+extern int siw_pd_add(struct siw_device *dev, struct siw_pd *pd);
+extern int siw_mem_add(struct siw_device *dev, struct siw_mem *mem);
+
+extern struct siw_wqe *siw_freeq_wqe_get(struct siw_qp *qp);
+
+extern int siw_invalidate_stag(struct siw_pd *pd, u32 stag);
+#endif