drivers/net/ethernet/mellanox/mlx4/cq.c - linux - Git at Google

 /*
  * Copyright (c) 2004, 2005 Topspin Communications.  All rights reserved.
  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
  * Copyright (c) 2005, 2006, 2007 Cisco Systems, Inc. All rights reserved.
  * Copyright (c) 2005, 2006, 2007, 2008 Mellanox Technologies. All rights reserved.
  * Copyright (c) 2004 Voltaire, Inc. 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/hardirq.h>
 #include <linux/export.h>

 #include <linux/mlx4/cmd.h>
 #include <linux/mlx4/cq.h>

 #include "mlx4.h"
 #include "icm.h"

 #define MLX4_CQ_STATUS_OK		( 0 << 28)
 #define MLX4_CQ_STATUS_OVERFLOW		( 9 << 28)
 #define MLX4_CQ_STATUS_WRITE_FAIL	(10 << 28)
 #define MLX4_CQ_FLAG_CC			( 1 << 18)
 #define MLX4_CQ_FLAG_OI			( 1 << 17)
 #define MLX4_CQ_STATE_ARMED		( 9 <<  8)
 #define MLX4_CQ_STATE_ARMED_SOL		( 6 <<  8)
 #define MLX4_EQ_STATE_FIRED		(10 <<  8)

 #define TASKLET_MAX_TIME 2
 #define TASKLET_MAX_TIME_JIFFIES msecs_to_jiffies(TASKLET_MAX_TIME)

 void mlx4_cq_tasklet_cb(struct tasklet_struct *t)
 {
 	unsigned long flags;
 	unsigned long end = jiffies + TASKLET_MAX_TIME_JIFFIES;
 	struct mlx4_eq_tasklet *ctx = from_tasklet(ctx, t, task);
 	struct mlx4_cq *mcq, *temp;

 	spin_lock_irqsave(&ctx->lock, flags);
 	list_splice_tail_init(&ctx->list, &ctx->process_list);
 	spin_unlock_irqrestore(&ctx->lock, flags);

 	list_for_each_entry_safe(mcq, temp, &ctx->process_list, tasklet_ctx.list) {
 		list_del_init(&mcq->tasklet_ctx.list);
 		mcq->tasklet_ctx.comp(mcq);
 		if (refcount_dec_and_test(&mcq->refcount))
 			complete(&mcq->free);
 		if (time_after(jiffies, end))
 			break;
 	}

 	if (!list_empty(&ctx->process_list))
 		tasklet_schedule(&ctx->task);
 }

 static void mlx4_add_cq_to_tasklet(struct mlx4_cq *cq)
 {
 	struct mlx4_eq_tasklet *tasklet_ctx = cq->tasklet_ctx.priv;
 	unsigned long flags;
 	bool kick;

 	spin_lock_irqsave(&tasklet_ctx->lock, flags);
 	/* When migrating CQs between EQs will be implemented, please note
 	 * that you need to sync this point. It is possible that
 	 * while migrating a CQ, completions on the old EQs could
 	 * still arrive.
 	 */
 	if (list_empty_careful(&cq->tasklet_ctx.list)) {
 		refcount_inc(&cq->refcount);
 		kick = list_empty(&tasklet_ctx->list);
 		list_add_tail(&cq->tasklet_ctx.list, &tasklet_ctx->list);
 		if (kick)
 			tasklet_schedule(&tasklet_ctx->task);
 	}
 	spin_unlock_irqrestore(&tasklet_ctx->lock, flags);
 }

 void mlx4_cq_completion(struct mlx4_dev *dev, u32 cqn)
 {
 	struct mlx4_cq *cq;

 	rcu_read_lock();
 	cq = radix_tree_lookup(&mlx4_priv(dev)->cq_table.tree,
 			       cqn & (dev->caps.num_cqs - 1));
 	rcu_read_unlock();

 	if (!cq) {
 		mlx4_dbg(dev, "Completion event for bogus CQ %08x\n", cqn);
 		return;
 	}

 	/* Acessing the CQ outside of rcu_read_lock is safe, because
 	 * the CQ is freed only after interrupt handling is completed.
 	 */
 	++cq->arm_sn;

 	cq->comp(cq);
 }

 void mlx4_cq_event(struct mlx4_dev *dev, u32 cqn, int event_type)
 {
 	struct mlx4_cq_table *cq_table = &mlx4_priv(dev)->cq_table;
 	struct mlx4_cq *cq;

 	rcu_read_lock();
 	cq = radix_tree_lookup(&cq_table->tree, cqn & (dev->caps.num_cqs - 1));
 	rcu_read_unlock();

 	if (!cq) {
 		mlx4_dbg(dev, "Async event for bogus CQ %08x\n", cqn);
 		return;
 	}

 	/* Acessing the CQ outside of rcu_read_lock is safe, because
 	 * the CQ is freed only after interrupt handling is completed.
 	 */
 	cq->event(cq, event_type);
 }

 static int mlx4_SW2HW_CQ(struct mlx4_dev *dev, struct mlx4_cmd_mailbox *mailbox,
 			 int cq_num, u8 opmod)
 {
 	return mlx4_cmd(dev, mailbox->dma, cq_num, opmod,
 			MLX4_CMD_SW2HW_CQ, MLX4_CMD_TIME_CLASS_A,
 			MLX4_CMD_WRAPPED);
 }

 static int mlx4_MODIFY_CQ(struct mlx4_dev *dev, struct mlx4_cmd_mailbox *mailbox,
 			 int cq_num, u32 opmod)
 {
 	return mlx4_cmd(dev, mailbox->dma, cq_num, opmod, MLX4_CMD_MODIFY_CQ,
 			MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
 }

 static int mlx4_HW2SW_CQ(struct mlx4_dev *dev, struct mlx4_cmd_mailbox *mailbox,
 			 int cq_num)
 {
 	return mlx4_cmd_box(dev, 0, mailbox ? mailbox->dma : 0,
 			    cq_num, mailbox ? 0 : 1, MLX4_CMD_HW2SW_CQ,
 			    MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
 }

 int mlx4_cq_modify(struct mlx4_dev *dev, struct mlx4_cq *cq,
 		   u16 count, u16 period)
 {
 	struct mlx4_cmd_mailbox *mailbox;
 	struct mlx4_cq_context *cq_context;
 	int err;

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

 	cq_context = mailbox->buf;
 	cq_context->cq_max_count = cpu_to_be16(count);
 	cq_context->cq_period    = cpu_to_be16(period);

 	err = mlx4_MODIFY_CQ(dev, mailbox, cq->cqn, 1);

 	mlx4_free_cmd_mailbox(dev, mailbox);
 	return err;
 }
 EXPORT_SYMBOL_GPL(mlx4_cq_modify);

 int mlx4_cq_resize(struct mlx4_dev *dev, struct mlx4_cq *cq,
 		   int entries, struct mlx4_mtt *mtt)
 {
 	struct mlx4_cmd_mailbox *mailbox;
 	struct mlx4_cq_context *cq_context;
 	u64 mtt_addr;
 	int err;

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

 	cq_context = mailbox->buf;
 	cq_context->logsize_usrpage = cpu_to_be32(ilog2(entries) << 24);
 	cq_context->log_page_size   = mtt->page_shift - 12;
 	mtt_addr = mlx4_mtt_addr(dev, mtt);
 	cq_context->mtt_base_addr_h = mtt_addr >> 32;
 	cq_context->mtt_base_addr_l = cpu_to_be32(mtt_addr & 0xffffffff);

 	err = mlx4_MODIFY_CQ(dev, mailbox, cq->cqn, 0);

 	mlx4_free_cmd_mailbox(dev, mailbox);
 	return err;
 }
 EXPORT_SYMBOL_GPL(mlx4_cq_resize);

 int __mlx4_cq_alloc_icm(struct mlx4_dev *dev, int *cqn)
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
 	struct mlx4_cq_table *cq_table = &priv->cq_table;
 	int err;

 	*cqn = mlx4_bitmap_alloc(&cq_table->bitmap);
 	if (*cqn == -1)
 		return -ENOMEM;

 	err = mlx4_table_get(dev, &cq_table->table, *cqn);
 	if (err)
 		goto err_out;

 	err = mlx4_table_get(dev, &cq_table->cmpt_table, *cqn);
 	if (err)
 		goto err_put;
 	return 0;

 err_put:
 	mlx4_table_put(dev, &cq_table->table, *cqn);

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

 static int mlx4_cq_alloc_icm(struct mlx4_dev *dev, int *cqn, u8 usage)
 {
 	u32 in_modifier = RES_CQ | (((u32)usage & 3) << 30);
 	u64 out_param;
 	int err;

 	if (mlx4_is_mfunc(dev)) {
 		err = mlx4_cmd_imm(dev, 0, &out_param, in_modifier,
 				   RES_OP_RESERVE_AND_MAP, MLX4_CMD_ALLOC_RES,
 				   MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
 		if (err)
 			return err;
 		else {
 			*cqn = get_param_l(&out_param);
 			return 0;
 		}
 	}
 	return __mlx4_cq_alloc_icm(dev, cqn);
 }

 void __mlx4_cq_free_icm(struct mlx4_dev *dev, int cqn)
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
 	struct mlx4_cq_table *cq_table = &priv->cq_table;

 	mlx4_table_put(dev, &cq_table->cmpt_table, cqn);
 	mlx4_table_put(dev, &cq_table->table, cqn);
 	mlx4_bitmap_free(&cq_table->bitmap, cqn, MLX4_NO_RR);
 }

 static void mlx4_cq_free_icm(struct mlx4_dev *dev, int cqn)
 {
 	u64 in_param = 0;
 	int err;

 	if (mlx4_is_mfunc(dev)) {
 		set_param_l(&in_param, cqn);
 		err = mlx4_cmd(dev, in_param, RES_CQ, RES_OP_RESERVE_AND_MAP,
 			       MLX4_CMD_FREE_RES,
 			       MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
 		if (err)
 			mlx4_warn(dev, "Failed freeing cq:%d\n", cqn);
 	} else
 		__mlx4_cq_free_icm(dev, cqn);
 }

 static int mlx4_init_user_cqes(void *buf, int entries, int cqe_size)
 {
 	int entries_per_copy = PAGE_SIZE / cqe_size;
 	void *init_ents;
 	int err = 0;
 	int i;

 	init_ents = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!init_ents)
 		return -ENOMEM;

 	/* Populate a list of CQ entries to reduce the number of
 	 * copy_to_user calls. 0xcc is the initialization value
 	 * required by the FW.
 	 */
 	memset(init_ents, 0xcc, PAGE_SIZE);

 	if (entries_per_copy < entries) {
 		for (i = 0; i < entries / entries_per_copy; i++) {
 			err = copy_to_user((void __user *)buf, init_ents, PAGE_SIZE) ?
 				-EFAULT : 0;
 			if (err)
 				goto out;

 			buf += PAGE_SIZE;
 		}
 	} else {
 		err = copy_to_user((void __user *)buf, init_ents, entries * cqe_size) ?
 			-EFAULT : 0;
 	}

 out:
 	kfree(init_ents);

 	return err;
 }

 static void mlx4_init_kernel_cqes(struct mlx4_buf *buf,
 				  int entries,
 				  int cqe_size)
 {
 	int i;

 	if (buf->nbufs == 1)
 		memset(buf->direct.buf, 0xcc, entries * cqe_size);
 	else
 		for (i = 0; i < buf->npages; i++)
 			memset(buf->page_list[i].buf, 0xcc,
 			       1UL << buf->page_shift);
 }

 int mlx4_cq_alloc(struct mlx4_dev *dev, int nent,
 		  struct mlx4_mtt *mtt, struct mlx4_uar *uar, u64 db_rec,
 		  struct mlx4_cq *cq, unsigned vector, int collapsed,
 		  int timestamp_en, void *buf_addr, bool user_cq)
 {
 	bool sw_cq_init = dev->caps.flags2 & MLX4_DEV_CAP_FLAG2_SW_CQ_INIT;
 	struct mlx4_priv *priv = mlx4_priv(dev);
 	struct mlx4_cq_table *cq_table = &priv->cq_table;
 	struct mlx4_cmd_mailbox *mailbox;
 	struct mlx4_cq_context *cq_context;
 	u64 mtt_addr;
 	int err;

 	if (vector >= dev->caps.num_comp_vectors)
 		return -EINVAL;

 	cq->vector = vector;

 	err = mlx4_cq_alloc_icm(dev, &cq->cqn, cq->usage);
 	if (err)
 		return err;

 	spin_lock(&cq_table->lock);
 	err = radix_tree_insert(&cq_table->tree, cq->cqn, cq);
 	spin_unlock(&cq_table->lock);
 	if (err)
 		goto err_icm;

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

 	cq_context = mailbox->buf;
 	cq_context->flags	    = cpu_to_be32(!!collapsed << 18);
 	if (timestamp_en)
 		cq_context->flags  |= cpu_to_be32(1 << 19);

 	cq_context->logsize_usrpage =
 		cpu_to_be32((ilog2(nent) << 24) |
 			    mlx4_to_hw_uar_index(dev, uar->index));
 	cq_context->comp_eqn	    = priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(vector)].eqn;
 	cq_context->log_page_size   = mtt->page_shift - MLX4_ICM_PAGE_SHIFT;

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

 	if (sw_cq_init) {
 		if (user_cq) {
 			err = mlx4_init_user_cqes(buf_addr, nent,
 						  dev->caps.cqe_size);
 			if (err)
 				sw_cq_init = false;
 		} else {
 			mlx4_init_kernel_cqes(buf_addr, nent,
 					      dev->caps.cqe_size);
 		}
 	}

 	err = mlx4_SW2HW_CQ(dev, mailbox, cq->cqn, sw_cq_init);

 	mlx4_free_cmd_mailbox(dev, mailbox);
 	if (err)
 		goto err_radix;

 	cq->cons_index = 0;
 	cq->arm_sn     = 1;
 	cq->uar        = uar;
 	refcount_set(&cq->refcount, 1);
 	init_completion(&cq->free);
 	cq->comp = mlx4_add_cq_to_tasklet;
 	cq->tasklet_ctx.priv =
 		&priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(vector)].tasklet_ctx;
 	INIT_LIST_HEAD(&cq->tasklet_ctx.list);


 	cq->irq = priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(vector)].irq;
 	return 0;

 err_radix:
 	spin_lock(&cq_table->lock);
 	radix_tree_delete(&cq_table->tree, cq->cqn);
 	spin_unlock(&cq_table->lock);

 err_icm:
 	mlx4_cq_free_icm(dev, cq->cqn);

 	return err;
 }
 EXPORT_SYMBOL_GPL(mlx4_cq_alloc);

 void mlx4_cq_free(struct mlx4_dev *dev, struct mlx4_cq *cq)
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
 	struct mlx4_cq_table *cq_table = &priv->cq_table;
 	int err;

 	err = mlx4_HW2SW_CQ(dev, NULL, cq->cqn);
 	if (err)
 		mlx4_warn(dev, "HW2SW_CQ failed (%d) for CQN %06x\n", err, cq->cqn);

 	spin_lock(&cq_table->lock);
 	radix_tree_delete(&cq_table->tree, cq->cqn);
 	spin_unlock(&cq_table->lock);

 	synchronize_irq(priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(cq->vector)].irq);
 	if (priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(cq->vector)].irq !=
 	    priv->eq_table.eq[MLX4_EQ_ASYNC].irq)
 		synchronize_irq(priv->eq_table.eq[MLX4_EQ_ASYNC].irq);

 	if (refcount_dec_and_test(&cq->refcount))
 		complete(&cq->free);
 	wait_for_completion(&cq->free);

 	mlx4_cq_free_icm(dev, cq->cqn);
 }
 EXPORT_SYMBOL_GPL(mlx4_cq_free);

 int mlx4_init_cq_table(struct mlx4_dev *dev)
 {
 	struct mlx4_cq_table *cq_table = &mlx4_priv(dev)->cq_table;

 	spin_lock_init(&cq_table->lock);
 	INIT_RADIX_TREE(&cq_table->tree, GFP_ATOMIC);
 	if (mlx4_is_slave(dev))
 		return 0;

 	return mlx4_bitmap_init(&cq_table->bitmap, dev->caps.num_cqs,
 				dev->caps.num_cqs - 1, dev->caps.reserved_cqs, 0);
 }

 void mlx4_cleanup_cq_table(struct mlx4_dev *dev)
 {
 	if (mlx4_is_slave(dev))
 		return;
 	/* Nothing to do to clean up radix_tree */
 	mlx4_bitmap_cleanup(&mlx4_priv(dev)->cq_table.bitmap);
 }
	/*
	* Copyright (c) 2004, 2005 Topspin Communications. All rights reserved.
	* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
	* Copyright (c) 2005, 2006, 2007 Cisco Systems, Inc. All rights reserved.
	* Copyright (c) 2005, 2006, 2007, 2008 Mellanox Technologies. All rights reserved.
	* Copyright (c) 2004 Voltaire, Inc. 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/hardirq.h>
	#include <linux/export.h>

	#include <linux/mlx4/cmd.h>
	#include <linux/mlx4/cq.h>

	#include "mlx4.h"
	#include "icm.h"

	#define MLX4_CQ_STATUS_OK ( 0 << 28)
	#define MLX4_CQ_STATUS_OVERFLOW ( 9 << 28)
	#define MLX4_CQ_STATUS_WRITE_FAIL (10 << 28)
	#define MLX4_CQ_FLAG_CC ( 1 << 18)
	#define MLX4_CQ_FLAG_OI ( 1 << 17)
	#define MLX4_CQ_STATE_ARMED ( 9 << 8)
	#define MLX4_CQ_STATE_ARMED_SOL ( 6 << 8)
	#define MLX4_EQ_STATE_FIRED (10 << 8)

	#define TASKLET_MAX_TIME 2
	#define TASKLET_MAX_TIME_JIFFIES msecs_to_jiffies(TASKLET_MAX_TIME)

	void mlx4_cq_tasklet_cb(struct tasklet_struct *t)
	{
	unsigned long flags;
	unsigned long end = jiffies + TASKLET_MAX_TIME_JIFFIES;
	struct mlx4_eq_tasklet *ctx = from_tasklet(ctx, t, task);
	struct mlx4_cq mcq, temp;

	spin_lock_irqsave(&ctx->lock, flags);
	list_splice_tail_init(&ctx->list, &ctx->process_list);
	spin_unlock_irqrestore(&ctx->lock, flags);

	list_for_each_entry_safe(mcq, temp, &ctx->process_list, tasklet_ctx.list) {
	list_del_init(&mcq->tasklet_ctx.list);
	mcq->tasklet_ctx.comp(mcq);
	if (refcount_dec_and_test(&mcq->refcount))
	complete(&mcq->free);
	if (time_after(jiffies, end))
	break;
	}

	if (!list_empty(&ctx->process_list))
	tasklet_schedule(&ctx->task);
	}

	static void mlx4_add_cq_to_tasklet(struct mlx4_cq *cq)
	{
	struct mlx4_eq_tasklet *tasklet_ctx = cq->tasklet_ctx.priv;
	unsigned long flags;
	bool kick;

	spin_lock_irqsave(&tasklet_ctx->lock, flags);
	/* When migrating CQs between EQs will be implemented, please note
	* that you need to sync this point. It is possible that
	* while migrating a CQ, completions on the old EQs could
	* still arrive.
	*/
	if (list_empty_careful(&cq->tasklet_ctx.list)) {
	refcount_inc(&cq->refcount);
	kick = list_empty(&tasklet_ctx->list);
	list_add_tail(&cq->tasklet_ctx.list, &tasklet_ctx->list);
	if (kick)
	tasklet_schedule(&tasklet_ctx->task);
	}
	spin_unlock_irqrestore(&tasklet_ctx->lock, flags);
	}

	void mlx4_cq_completion(struct mlx4_dev *dev, u32 cqn)
	{
	struct mlx4_cq *cq;

	rcu_read_lock();
	cq = radix_tree_lookup(&mlx4_priv(dev)->cq_table.tree,
	cqn & (dev->caps.num_cqs - 1));
	rcu_read_unlock();

	if (!cq) {
	mlx4_dbg(dev, "Completion event for bogus CQ %08x\n", cqn);
	return;
	}

	/* Acessing the CQ outside of rcu_read_lock is safe, because
	* the CQ is freed only after interrupt handling is completed.
	*/
	++cq->arm_sn;

	cq->comp(cq);
	}

	void mlx4_cq_event(struct mlx4_dev *dev, u32 cqn, int event_type)
	{
	struct mlx4_cq_table *cq_table = &mlx4_priv(dev)->cq_table;
	struct mlx4_cq *cq;

	rcu_read_lock();
	cq = radix_tree_lookup(&cq_table->tree, cqn & (dev->caps.num_cqs - 1));
	rcu_read_unlock();

	if (!cq) {
	mlx4_dbg(dev, "Async event for bogus CQ %08x\n", cqn);
	return;
	}

	/* Acessing the CQ outside of rcu_read_lock is safe, because
	* the CQ is freed only after interrupt handling is completed.
	*/
	cq->event(cq, event_type);
	}

	static int mlx4_SW2HW_CQ(struct mlx4_dev dev, struct mlx4_cmd_mailbox mailbox,
	int cq_num, u8 opmod)
	{
	return mlx4_cmd(dev, mailbox->dma, cq_num, opmod,
	MLX4_CMD_SW2HW_CQ, MLX4_CMD_TIME_CLASS_A,
	MLX4_CMD_WRAPPED);
	}

	static int mlx4_MODIFY_CQ(struct mlx4_dev dev, struct mlx4_cmd_mailbox mailbox,
	int cq_num, u32 opmod)
	{
	return mlx4_cmd(dev, mailbox->dma, cq_num, opmod, MLX4_CMD_MODIFY_CQ,
	MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
	}

	static int mlx4_HW2SW_CQ(struct mlx4_dev dev, struct mlx4_cmd_mailbox mailbox,
	int cq_num)
	{
	return mlx4_cmd_box(dev, 0, mailbox ? mailbox->dma : 0,
	cq_num, mailbox ? 0 : 1, MLX4_CMD_HW2SW_CQ,
	MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
	}

	int mlx4_cq_modify(struct mlx4_dev dev, struct mlx4_cq cq,
	u16 count, u16 period)
	{
	struct mlx4_cmd_mailbox *mailbox;
	struct mlx4_cq_context *cq_context;
	int err;

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

	cq_context = mailbox->buf;
	cq_context->cq_max_count = cpu_to_be16(count);
	cq_context->cq_period = cpu_to_be16(period);

	err = mlx4_MODIFY_CQ(dev, mailbox, cq->cqn, 1);

	mlx4_free_cmd_mailbox(dev, mailbox);
	return err;
	}
	EXPORT_SYMBOL_GPL(mlx4_cq_modify);

	int mlx4_cq_resize(struct mlx4_dev dev, struct mlx4_cq cq,
	int entries, struct mlx4_mtt *mtt)
	{
	struct mlx4_cmd_mailbox *mailbox;
	struct mlx4_cq_context *cq_context;
	u64 mtt_addr;
	int err;

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

	cq_context = mailbox->buf;
	cq_context->logsize_usrpage = cpu_to_be32(ilog2(entries) << 24);
	cq_context->log_page_size = mtt->page_shift - 12;
	mtt_addr = mlx4_mtt_addr(dev, mtt);
	cq_context->mtt_base_addr_h = mtt_addr >> 32;
	cq_context->mtt_base_addr_l = cpu_to_be32(mtt_addr & 0xffffffff);

	err = mlx4_MODIFY_CQ(dev, mailbox, cq->cqn, 0);

	mlx4_free_cmd_mailbox(dev, mailbox);
	return err;
	}
	EXPORT_SYMBOL_GPL(mlx4_cq_resize);

	int __mlx4_cq_alloc_icm(struct mlx4_dev dev, int cqn)
	{
	struct mlx4_priv *priv = mlx4_priv(dev);
	struct mlx4_cq_table *cq_table = &priv->cq_table;
	int err;

	*cqn = mlx4_bitmap_alloc(&cq_table->bitmap);
	if (*cqn == -1)
	return -ENOMEM;

	err = mlx4_table_get(dev, &cq_table->table, *cqn);
	if (err)
	goto err_out;

	err = mlx4_table_get(dev, &cq_table->cmpt_table, *cqn);
	if (err)
	goto err_put;
	return 0;

	err_put:
	mlx4_table_put(dev, &cq_table->table, *cqn);

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

	static int mlx4_cq_alloc_icm(struct mlx4_dev dev, int cqn, u8 usage)
	{
	u32 in_modifier = RES_CQ \| (((u32)usage & 3) << 30);
	u64 out_param;
	int err;

	if (mlx4_is_mfunc(dev)) {
	err = mlx4_cmd_imm(dev, 0, &out_param, in_modifier,
	RES_OP_RESERVE_AND_MAP, MLX4_CMD_ALLOC_RES,
	MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
	if (err)
	return err;
	else {
	*cqn = get_param_l(&out_param);
	return 0;
	}
	}
	return __mlx4_cq_alloc_icm(dev, cqn);
	}

	void __mlx4_cq_free_icm(struct mlx4_dev *dev, int cqn)
	{
	struct mlx4_priv *priv = mlx4_priv(dev);
	struct mlx4_cq_table *cq_table = &priv->cq_table;

	mlx4_table_put(dev, &cq_table->cmpt_table, cqn);
	mlx4_table_put(dev, &cq_table->table, cqn);
	mlx4_bitmap_free(&cq_table->bitmap, cqn, MLX4_NO_RR);
	}

	static void mlx4_cq_free_icm(struct mlx4_dev *dev, int cqn)
	{
	u64 in_param = 0;
	int err;

	if (mlx4_is_mfunc(dev)) {
	set_param_l(&in_param, cqn);
	err = mlx4_cmd(dev, in_param, RES_CQ, RES_OP_RESERVE_AND_MAP,
	MLX4_CMD_FREE_RES,
	MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
	if (err)
	mlx4_warn(dev, "Failed freeing cq:%d\n", cqn);
	} else
	__mlx4_cq_free_icm(dev, cqn);
	}

	static int mlx4_init_user_cqes(void *buf, int entries, int cqe_size)
	{
	int entries_per_copy = PAGE_SIZE / cqe_size;
	void *init_ents;
	int err = 0;
	int i;

	init_ents = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (!init_ents)
	return -ENOMEM;

	/* Populate a list of CQ entries to reduce the number of
	* copy_to_user calls. 0xcc is the initialization value
	* required by the FW.
	*/
	memset(init_ents, 0xcc, PAGE_SIZE);

	if (entries_per_copy < entries) {
	for (i = 0; i < entries / entries_per_copy; i++) {
	err = copy_to_user((void __user *)buf, init_ents, PAGE_SIZE) ?
	-EFAULT : 0;
	if (err)
	goto out;

	buf += PAGE_SIZE;
	}
	} else {
	err = copy_to_user((void __user )buf, init_ents, entries cqe_size) ?
	-EFAULT : 0;
	}

	out:
	kfree(init_ents);

	return err;
	}

	static void mlx4_init_kernel_cqes(struct mlx4_buf *buf,
	int entries,
	int cqe_size)
	{
	int i;

	if (buf->nbufs == 1)
	memset(buf->direct.buf, 0xcc, entries * cqe_size);
	else
	for (i = 0; i < buf->npages; i++)
	memset(buf->page_list[i].buf, 0xcc,
	1UL << buf->page_shift);
	}

	int mlx4_cq_alloc(struct mlx4_dev *dev, int nent,
	struct mlx4_mtt mtt, struct mlx4_uar uar, u64 db_rec,
	struct mlx4_cq *cq, unsigned vector, int collapsed,
	int timestamp_en, void *buf_addr, bool user_cq)
	{
	bool sw_cq_init = dev->caps.flags2 & MLX4_DEV_CAP_FLAG2_SW_CQ_INIT;
	struct mlx4_priv *priv = mlx4_priv(dev);
	struct mlx4_cq_table *cq_table = &priv->cq_table;
	struct mlx4_cmd_mailbox *mailbox;
	struct mlx4_cq_context *cq_context;
	u64 mtt_addr;
	int err;

	if (vector >= dev->caps.num_comp_vectors)
	return -EINVAL;

	cq->vector = vector;

	err = mlx4_cq_alloc_icm(dev, &cq->cqn, cq->usage);
	if (err)
	return err;

	spin_lock(&cq_table->lock);
	err = radix_tree_insert(&cq_table->tree, cq->cqn, cq);
	spin_unlock(&cq_table->lock);
	if (err)
	goto err_icm;

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

	cq_context = mailbox->buf;
	cq_context->flags = cpu_to_be32(!!collapsed << 18);
	if (timestamp_en)
	cq_context->flags \|= cpu_to_be32(1 << 19);

	cq_context->logsize_usrpage =
	cpu_to_be32((ilog2(nent) << 24) \|
	mlx4_to_hw_uar_index(dev, uar->index));
	cq_context->comp_eqn = priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(vector)].eqn;
	cq_context->log_page_size = mtt->page_shift - MLX4_ICM_PAGE_SHIFT;

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

	if (sw_cq_init) {
	if (user_cq) {
	err = mlx4_init_user_cqes(buf_addr, nent,
	dev->caps.cqe_size);
	if (err)
	sw_cq_init = false;
	} else {
	mlx4_init_kernel_cqes(buf_addr, nent,
	dev->caps.cqe_size);
	}
	}

	err = mlx4_SW2HW_CQ(dev, mailbox, cq->cqn, sw_cq_init);

	mlx4_free_cmd_mailbox(dev, mailbox);
	if (err)
	goto err_radix;

	cq->cons_index = 0;
	cq->arm_sn = 1;
	cq->uar = uar;
	refcount_set(&cq->refcount, 1);
	init_completion(&cq->free);
	cq->comp = mlx4_add_cq_to_tasklet;
	cq->tasklet_ctx.priv =
	&priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(vector)].tasklet_ctx;
	INIT_LIST_HEAD(&cq->tasklet_ctx.list);


	cq->irq = priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(vector)].irq;
	return 0;

	err_radix:
	spin_lock(&cq_table->lock);
	radix_tree_delete(&cq_table->tree, cq->cqn);
	spin_unlock(&cq_table->lock);

	err_icm:
	mlx4_cq_free_icm(dev, cq->cqn);

	return err;
	}
	EXPORT_SYMBOL_GPL(mlx4_cq_alloc);

	void mlx4_cq_free(struct mlx4_dev dev, struct mlx4_cq cq)
	{
	struct mlx4_priv *priv = mlx4_priv(dev);
	struct mlx4_cq_table *cq_table = &priv->cq_table;
	int err;

	err = mlx4_HW2SW_CQ(dev, NULL, cq->cqn);
	if (err)
	mlx4_warn(dev, "HW2SW_CQ failed (%d) for CQN %06x\n", err, cq->cqn);

	spin_lock(&cq_table->lock);
	radix_tree_delete(&cq_table->tree, cq->cqn);
	spin_unlock(&cq_table->lock);

	synchronize_irq(priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(cq->vector)].irq);
	if (priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(cq->vector)].irq !=
	priv->eq_table.eq[MLX4_EQ_ASYNC].irq)
	synchronize_irq(priv->eq_table.eq[MLX4_EQ_ASYNC].irq);

	if (refcount_dec_and_test(&cq->refcount))
	complete(&cq->free);
	wait_for_completion(&cq->free);

	mlx4_cq_free_icm(dev, cq->cqn);
	}
	EXPORT_SYMBOL_GPL(mlx4_cq_free);

	int mlx4_init_cq_table(struct mlx4_dev *dev)
	{
	struct mlx4_cq_table *cq_table = &mlx4_priv(dev)->cq_table;

	spin_lock_init(&cq_table->lock);
	INIT_RADIX_TREE(&cq_table->tree, GFP_ATOMIC);
	if (mlx4_is_slave(dev))
	return 0;

	return mlx4_bitmap_init(&cq_table->bitmap, dev->caps.num_cqs,
	dev->caps.num_cqs - 1, dev->caps.reserved_cqs, 0);
	}

	void mlx4_cleanup_cq_table(struct mlx4_dev *dev)
	{
	if (mlx4_is_slave(dev))
	return;
	/* Nothing to do to clean up radix_tree */
	mlx4_bitmap_cleanup(&mlx4_priv(dev)->cq_table.bitmap);
	}