kern/drivers/net/mlx4/srq.c - upstream - Git at Google

 /*
  * Copyright (c) 2006, 2007 Cisco Systems, Inc. All rights reserved.
  * Copyright (c) 2007, 2008 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 <linux/mlx4/cmd.h>
 #include <linux/mlx4/srq.h>
 #include "mlx4.h"
 #include "icm.h"

 void mlx4_srq_event(struct mlx4_dev *dev, uint32_t srqn, int event_type)
 {
 	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
 	struct mlx4_srq *srq;

 	spin_lock_irqsave(&srq_table->lock);

 	srq = radix_tree_lookup(&srq_table->tree, srqn & (dev->caps.num_srqs - 1));
 	if (srq)
 		atomic_inc(&srq->refcount);

 	spin_unlock_irqsave(&srq_table->lock);

 	if (!srq) {
 		mlx4_warn(dev, "Async event for bogus SRQ %08x\n", srqn);
 		return;
 	}

 	srq->event(srq, event_type);

 	if (atomic_sub_and_test(&srq->refcount, 1))
 		complete(&srq->free);
 }

 static int mlx4_SW2HW_SRQ(struct mlx4_dev *dev, struct mlx4_cmd_mailbox *mailbox,
 			  int srq_num)
 {
 	return mlx4_cmd(dev, mailbox->dma, srq_num, 0,
 			MLX4_CMD_SW2HW_SRQ, MLX4_CMD_TIME_CLASS_A,
 			MLX4_CMD_WRAPPED);
 }

 static int mlx4_HW2SW_SRQ(struct mlx4_dev *dev, struct mlx4_cmd_mailbox *mailbox,
 			  int srq_num)
 {
 	return mlx4_cmd_box(dev, 0, mailbox ? mailbox->dma : 0, srq_num,
 			    mailbox ? 0 : 1, MLX4_CMD_HW2SW_SRQ,
 			    MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
 }

 static int mlx4_ARM_SRQ(struct mlx4_dev *dev, int srq_num, int limit_watermark)
 {
 	return mlx4_cmd(dev, limit_watermark, srq_num, 0, MLX4_CMD_ARM_SRQ,
 			MLX4_CMD_TIME_CLASS_B, MLX4_CMD_WRAPPED);
 }

 static int mlx4_QUERY_SRQ(struct mlx4_dev *dev, struct mlx4_cmd_mailbox *mailbox,
 			  int srq_num)
 {
 	return mlx4_cmd_box(dev, 0, mailbox->dma, srq_num, 0, MLX4_CMD_QUERY_SRQ,
 			    MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
 }

 int __mlx4_srq_alloc_icm(struct mlx4_dev *dev, int *srqn)
 {
 	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
 	int err;


 	*srqn = mlx4_bitmap_alloc(&srq_table->bitmap);
 	if (*srqn == -1)
 		return -ENOMEM;

 	err = mlx4_table_get(dev, &srq_table->table, *srqn, MEM_WAIT);
 	if (err)
 		goto err_out;

 	err = mlx4_table_get(dev, &srq_table->cmpt_table, *srqn, MEM_WAIT);
 	if (err)
 		goto err_put;
 	return 0;

 err_put:
 	mlx4_table_put(dev, &srq_table->table, *srqn);

 err_out:
 	mlx4_bitmap_free(&srq_table->bitmap, *srqn, MLX4_NO_RR);
 	return err;
 }

 static int mlx4_srq_alloc_icm(struct mlx4_dev *dev, int *srqn)
 {
 	uint64_t out_param;
 	int err;

 	if (mlx4_is_mfunc(dev)) {
 		err = mlx4_cmd_imm(dev, 0, &out_param, RES_SRQ,
 				   RES_OP_RESERVE_AND_MAP,
 				   MLX4_CMD_ALLOC_RES,
 				   MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
 		if (!err)
 			*srqn = get_param_l(&out_param);

 		return err;
 	}
 	return __mlx4_srq_alloc_icm(dev, srqn);
 }

 void __mlx4_srq_free_icm(struct mlx4_dev *dev, int srqn)
 {
 	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;

 	mlx4_table_put(dev, &srq_table->cmpt_table, srqn);
 	mlx4_table_put(dev, &srq_table->table, srqn);
 	mlx4_bitmap_free(&srq_table->bitmap, srqn, MLX4_NO_RR);
 }

 static void mlx4_srq_free_icm(struct mlx4_dev *dev, int srqn)
 {
 	uint64_t in_param = 0;

 	if (mlx4_is_mfunc(dev)) {
 		set_param_l(&in_param, srqn);
 		if (mlx4_cmd(dev, in_param, RES_SRQ, RES_OP_RESERVE_AND_MAP,
 			     MLX4_CMD_FREE_RES,
 			     MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED))
 			mlx4_warn(dev, "Failed freeing cq:%d\n", srqn);
 		return;
 	}
 	__mlx4_srq_free_icm(dev, srqn);
 }

 int mlx4_srq_alloc(struct mlx4_dev *dev, uint32_t pdn, uint32_t cqn,
 		   uint16_t xrcd,
 		   struct mlx4_mtt *mtt, uint64_t db_rec,
 		   struct mlx4_srq *srq)
 {
 	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
 	struct mlx4_cmd_mailbox *mailbox;
 	struct mlx4_srq_context *srq_context;
 	uint64_t mtt_addr;
 	int err;

 	err = mlx4_srq_alloc_icm(dev, &srq->srqn);
 	if (err)
 		return err;

 	spin_lock_irqsave(&srq_table->lock);
 	err = radix_tree_insert(&srq_table->tree, srq->srqn, srq);
 	spin_unlock_irqsave(&srq_table->lock);
 	if (err)
 		goto err_icm;

 	mailbox = mlx4_alloc_cmd_mailbox(dev);
 	if (IS_ERR(mailbox)) {
 		err = PTR_ERR(mailbox);
 		goto err_radix;
 	}

 	srq_context = mailbox->buf;
 	srq_context->state_logsize_srqn = cpu_to_be32((LOG2_UP(srq->max) << 24) |
 						      srq->srqn);
 	srq_context->logstride          = srq->wqe_shift - 4;
 	srq_context->xrcd		= cpu_to_be16(xrcd);
 	srq_context->pg_offset_cqn	= cpu_to_be32(cqn & 0xffffff);
 	srq_context->log_page_size      = mtt->page_shift - MLX4_ICM_PAGE_SHIFT;

 	mtt_addr = mlx4_mtt_addr(dev, mtt);
 	srq_context->mtt_base_addr_h    = mtt_addr >> 32;
 	srq_context->mtt_base_addr_l    = cpu_to_be32(mtt_addr & 0xffffffff);
 	srq_context->pd			= cpu_to_be32(pdn);
 	srq_context->db_rec_addr        = cpu_to_be64(db_rec);

 	err = mlx4_SW2HW_SRQ(dev, mailbox, srq->srqn);
 	mlx4_free_cmd_mailbox(dev, mailbox);
 	if (err)
 		goto err_radix;

 	atomic_set(&srq->refcount, 1);
 	init_completion(&srq->free);

 	return 0;

 err_radix:
 	spin_lock_irqsave(&srq_table->lock);
 	radix_tree_delete(&srq_table->tree, srq->srqn);
 	spin_unlock_irqsave(&srq_table->lock);

 err_icm:
 	mlx4_srq_free_icm(dev, srq->srqn);
 	return err;
 }
 EXPORT_SYMBOL_GPL(mlx4_srq_alloc);

 void mlx4_srq_free(struct mlx4_dev *dev, struct mlx4_srq *srq)
 {
 	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
 	int err;

 	err = mlx4_HW2SW_SRQ(dev, NULL, srq->srqn);
 	if (err)
 		mlx4_warn(dev, "HW2SW_SRQ failed (%d) for SRQN %06x\n", err, srq->srqn);

 	spin_lock_irqsave(&srq_table->lock);
 	radix_tree_delete(&srq_table->tree, srq->srqn);
 	spin_unlock_irqsave(&srq_table->lock);

 	if (atomic_sub_and_test(&srq->refcount, 1))
 		complete(&srq->free);
 	wait_for_completion(&srq->free);

 	mlx4_srq_free_icm(dev, srq->srqn);
 }
 EXPORT_SYMBOL_GPL(mlx4_srq_free);

 int mlx4_srq_arm(struct mlx4_dev *dev, struct mlx4_srq *srq, int limit_watermark)
 {
 	return mlx4_ARM_SRQ(dev, srq->srqn, limit_watermark);
 }
 EXPORT_SYMBOL_GPL(mlx4_srq_arm);

 int mlx4_srq_query(struct mlx4_dev *dev, struct mlx4_srq *srq, int *limit_watermark)
 {
 	struct mlx4_cmd_mailbox *mailbox;
 	struct mlx4_srq_context *srq_context;
 	int err;

 	mailbox = mlx4_alloc_cmd_mailbox(dev);
 	if (IS_ERR(mailbox))
 		return PTR_ERR(mailbox);

 	srq_context = mailbox->buf;

 	err = mlx4_QUERY_SRQ(dev, mailbox, srq->srqn);
 	if (err)
 		goto err_out;
 	*limit_watermark = be16_to_cpu(srq_context->limit_watermark);

 err_out:
 	mlx4_free_cmd_mailbox(dev, mailbox);
 	return err;
 }
 EXPORT_SYMBOL_GPL(mlx4_srq_query);

 int mlx4_init_srq_table(struct mlx4_dev *dev)
 {
 	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
 	int err;

 	spinlock_init_irqsave(&srq_table->lock);
 	INIT_RADIX_TREE(&srq_table->tree, 0);
 	if (mlx4_is_slave(dev))
 		return 0;

 	err = mlx4_bitmap_init(&srq_table->bitmap, dev->caps.num_srqs,
 			       dev->caps.num_srqs - 1, dev->caps.reserved_srqs, 0);
 	if (err)
 		return err;

 	return 0;
 }

 void mlx4_cleanup_srq_table(struct mlx4_dev *dev)
 {
 	if (mlx4_is_slave(dev))
 		return;
 	mlx4_bitmap_cleanup(&mlx4_priv(dev)->srq_table.bitmap);
 }

 struct mlx4_srq *mlx4_srq_lookup(struct mlx4_dev *dev, uint32_t srqn)
 {
 	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
 	struct mlx4_srq *srq;
 	unsigned long flags;

 	spin_lock_irqsave(&srq_table->lock);
 	srq = radix_tree_lookup(&srq_table->tree,
 				srqn & (dev->caps.num_srqs - 1));
 	spin_unlock_irqsave(&srq_table->lock);

 	return srq;
 }
 EXPORT_SYMBOL_GPL(mlx4_srq_lookup);
	/*
	* Copyright (c) 2006, 2007 Cisco Systems, Inc. All rights reserved.
	* Copyright (c) 2007, 2008 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 <linux/mlx4/cmd.h>
	#include <linux/mlx4/srq.h>
	#include "mlx4.h"
	#include "icm.h"

	void mlx4_srq_event(struct mlx4_dev *dev, uint32_t srqn, int event_type)
	{
	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
	struct mlx4_srq *srq;

	spin_lock_irqsave(&srq_table->lock);

	srq = radix_tree_lookup(&srq_table->tree, srqn & (dev->caps.num_srqs - 1));
	if (srq)
	atomic_inc(&srq->refcount);

	spin_unlock_irqsave(&srq_table->lock);

	if (!srq) {
	mlx4_warn(dev, "Async event for bogus SRQ %08x\n", srqn);
	return;
	}

	srq->event(srq, event_type);

	if (atomic_sub_and_test(&srq->refcount, 1))
	complete(&srq->free);
	}

	static int mlx4_SW2HW_SRQ(struct mlx4_dev dev, struct mlx4_cmd_mailbox mailbox,
	int srq_num)
	{
	return mlx4_cmd(dev, mailbox->dma, srq_num, 0,
	MLX4_CMD_SW2HW_SRQ, MLX4_CMD_TIME_CLASS_A,
	MLX4_CMD_WRAPPED);
	}

	static int mlx4_HW2SW_SRQ(struct mlx4_dev dev, struct mlx4_cmd_mailbox mailbox,
	int srq_num)
	{
	return mlx4_cmd_box(dev, 0, mailbox ? mailbox->dma : 0, srq_num,
	mailbox ? 0 : 1, MLX4_CMD_HW2SW_SRQ,
	MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
	}

	static int mlx4_ARM_SRQ(struct mlx4_dev *dev, int srq_num, int limit_watermark)
	{
	return mlx4_cmd(dev, limit_watermark, srq_num, 0, MLX4_CMD_ARM_SRQ,
	MLX4_CMD_TIME_CLASS_B, MLX4_CMD_WRAPPED);
	}

	static int mlx4_QUERY_SRQ(struct mlx4_dev dev, struct mlx4_cmd_mailbox mailbox,
	int srq_num)
	{
	return mlx4_cmd_box(dev, 0, mailbox->dma, srq_num, 0, MLX4_CMD_QUERY_SRQ,
	MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
	}

	int __mlx4_srq_alloc_icm(struct mlx4_dev dev, int srqn)
	{
	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
	int err;


	*srqn = mlx4_bitmap_alloc(&srq_table->bitmap);
	if (*srqn == -1)
	return -ENOMEM;

	err = mlx4_table_get(dev, &srq_table->table, *srqn, MEM_WAIT);
	if (err)
	goto err_out;

	err = mlx4_table_get(dev, &srq_table->cmpt_table, *srqn, MEM_WAIT);
	if (err)
	goto err_put;
	return 0;

	err_put:
	mlx4_table_put(dev, &srq_table->table, *srqn);

	err_out:
	mlx4_bitmap_free(&srq_table->bitmap, *srqn, MLX4_NO_RR);
	return err;
	}

	static int mlx4_srq_alloc_icm(struct mlx4_dev dev, int srqn)
	{
	uint64_t out_param;
	int err;

	if (mlx4_is_mfunc(dev)) {
	err = mlx4_cmd_imm(dev, 0, &out_param, RES_SRQ,
	RES_OP_RESERVE_AND_MAP,
	MLX4_CMD_ALLOC_RES,
	MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
	if (!err)
	*srqn = get_param_l(&out_param);

	return err;
	}
	return __mlx4_srq_alloc_icm(dev, srqn);
	}

	void __mlx4_srq_free_icm(struct mlx4_dev *dev, int srqn)
	{
	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;

	mlx4_table_put(dev, &srq_table->cmpt_table, srqn);
	mlx4_table_put(dev, &srq_table->table, srqn);
	mlx4_bitmap_free(&srq_table->bitmap, srqn, MLX4_NO_RR);
	}

	static void mlx4_srq_free_icm(struct mlx4_dev *dev, int srqn)
	{
	uint64_t in_param = 0;

	if (mlx4_is_mfunc(dev)) {
	set_param_l(&in_param, srqn);
	if (mlx4_cmd(dev, in_param, RES_SRQ, RES_OP_RESERVE_AND_MAP,
	MLX4_CMD_FREE_RES,
	MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED))
	mlx4_warn(dev, "Failed freeing cq:%d\n", srqn);
	return;
	}
	__mlx4_srq_free_icm(dev, srqn);
	}

	int mlx4_srq_alloc(struct mlx4_dev *dev, uint32_t pdn, uint32_t cqn,
	uint16_t xrcd,
	struct mlx4_mtt *mtt, uint64_t db_rec,
	struct mlx4_srq *srq)
	{
	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
	struct mlx4_cmd_mailbox *mailbox;
	struct mlx4_srq_context *srq_context;
	uint64_t mtt_addr;
	int err;

	err = mlx4_srq_alloc_icm(dev, &srq->srqn);
	if (err)
	return err;

	spin_lock_irqsave(&srq_table->lock);
	err = radix_tree_insert(&srq_table->tree, srq->srqn, srq);
	spin_unlock_irqsave(&srq_table->lock);
	if (err)
	goto err_icm;

	mailbox = mlx4_alloc_cmd_mailbox(dev);
	if (IS_ERR(mailbox)) {
	err = PTR_ERR(mailbox);
	goto err_radix;
	}

	srq_context = mailbox->buf;
	srq_context->state_logsize_srqn = cpu_to_be32((LOG2_UP(srq->max) << 24) \|
	srq->srqn);
	srq_context->logstride = srq->wqe_shift - 4;
	srq_context->xrcd = cpu_to_be16(xrcd);
	srq_context->pg_offset_cqn = cpu_to_be32(cqn & 0xffffff);
	srq_context->log_page_size = mtt->page_shift - MLX4_ICM_PAGE_SHIFT;

	mtt_addr = mlx4_mtt_addr(dev, mtt);
	srq_context->mtt_base_addr_h = mtt_addr >> 32;
	srq_context->mtt_base_addr_l = cpu_to_be32(mtt_addr & 0xffffffff);
	srq_context->pd = cpu_to_be32(pdn);
	srq_context->db_rec_addr = cpu_to_be64(db_rec);

	err = mlx4_SW2HW_SRQ(dev, mailbox, srq->srqn);
	mlx4_free_cmd_mailbox(dev, mailbox);
	if (err)
	goto err_radix;

	atomic_set(&srq->refcount, 1);
	init_completion(&srq->free);

	return 0;

	err_radix:
	spin_lock_irqsave(&srq_table->lock);
	radix_tree_delete(&srq_table->tree, srq->srqn);
	spin_unlock_irqsave(&srq_table->lock);

	err_icm:
	mlx4_srq_free_icm(dev, srq->srqn);
	return err;
	}
	EXPORT_SYMBOL_GPL(mlx4_srq_alloc);

	void mlx4_srq_free(struct mlx4_dev dev, struct mlx4_srq srq)
	{
	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
	int err;

	err = mlx4_HW2SW_SRQ(dev, NULL, srq->srqn);
	if (err)
	mlx4_warn(dev, "HW2SW_SRQ failed (%d) for SRQN %06x\n", err, srq->srqn);

	spin_lock_irqsave(&srq_table->lock);
	radix_tree_delete(&srq_table->tree, srq->srqn);
	spin_unlock_irqsave(&srq_table->lock);

	if (atomic_sub_and_test(&srq->refcount, 1))
	complete(&srq->free);
	wait_for_completion(&srq->free);

	mlx4_srq_free_icm(dev, srq->srqn);
	}
	EXPORT_SYMBOL_GPL(mlx4_srq_free);

	int mlx4_srq_arm(struct mlx4_dev dev, struct mlx4_srq srq, int limit_watermark)
	{
	return mlx4_ARM_SRQ(dev, srq->srqn, limit_watermark);
	}
	EXPORT_SYMBOL_GPL(mlx4_srq_arm);

	int mlx4_srq_query(struct mlx4_dev dev, struct mlx4_srq srq, int *limit_watermark)
	{
	struct mlx4_cmd_mailbox *mailbox;
	struct mlx4_srq_context *srq_context;
	int err;

	mailbox = mlx4_alloc_cmd_mailbox(dev);
	if (IS_ERR(mailbox))
	return PTR_ERR(mailbox);

	srq_context = mailbox->buf;

	err = mlx4_QUERY_SRQ(dev, mailbox, srq->srqn);
	if (err)
	goto err_out;
	*limit_watermark = be16_to_cpu(srq_context->limit_watermark);

	err_out:
	mlx4_free_cmd_mailbox(dev, mailbox);
	return err;
	}
	EXPORT_SYMBOL_GPL(mlx4_srq_query);

	int mlx4_init_srq_table(struct mlx4_dev *dev)
	{
	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
	int err;

	spinlock_init_irqsave(&srq_table->lock);
	INIT_RADIX_TREE(&srq_table->tree, 0);
	if (mlx4_is_slave(dev))
	return 0;

	err = mlx4_bitmap_init(&srq_table->bitmap, dev->caps.num_srqs,
	dev->caps.num_srqs - 1, dev->caps.reserved_srqs, 0);
	if (err)
	return err;

	return 0;
	}

	void mlx4_cleanup_srq_table(struct mlx4_dev *dev)
	{
	if (mlx4_is_slave(dev))
	return;
	mlx4_bitmap_cleanup(&mlx4_priv(dev)->srq_table.bitmap);
	}

	struct mlx4_srq mlx4_srq_lookup(struct mlx4_dev dev, uint32_t srqn)
	{
	struct mlx4_srq_table *srq_table = &mlx4_priv(dev)->srq_table;
	struct mlx4_srq *srq;
	unsigned long flags;

	spin_lock_irqsave(&srq_table->lock);
	srq = radix_tree_lookup(&srq_table->tree,
	srqn & (dev->caps.num_srqs - 1));
	spin_unlock_irqsave(&srq_table->lock);

	return srq;
	}
	EXPORT_SYMBOL_GPL(mlx4_srq_lookup);