text: /*
   * Copyright (c) 2006 QLogic, 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/module.h>
  #include <linux/vmalloc.h>
  #include <linux/mm.h>
  #include <linux/errno.h>
  #include <asm/pgtable.h>
  
  #include "ipath_verbs.h"
  
  /**
   * ipath_release_mmap_info - free mmap info structure
   * @ref: a pointer to the kref within struct ipath_mmap_info
   */
  void ipath_release_mmap_info(struct kref *ref)
  {
  	struct ipath_mmap_info *ip =
  		container_of(ref, struct ipath_mmap_info, ref);
  
  	vfree(ip->obj);
  	kfree(ip);
  }
  
  /*
   * open and close keep track of how many times the CQ is mapped,
   * to avoid releasing it.
   */
  static void ipath_vma_open(struct vm_area_struct *vma)
  {
  	struct ipath_mmap_info *ip = vma->vm_private_data;
  
  	kref_get(&ip->ref);
  	ip->mmap_cnt++;
  }
  
  static void ipath_vma_close(struct vm_area_struct *vma)
  {
  	struct ipath_mmap_info *ip = vma->vm_private_data;
  
  	ip->mmap_cnt--;
  	kref_put(&ip->ref, ipath_release_mmap_info);
  }
  
  static struct vm_operations_struct ipath_vm_ops = {
  	.open =     ipath_vma_open,
  	.close =    ipath_vma_close,
  };
  
  /**
   * ipath_mmap - create a new mmap region
   * @context: the IB user context of the process making the mmap() call
   * @vma: the VMA to be initialized
   * Return zero if the mmap is OK. Otherwise, return an errno.
   */
  int ipath_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
  {
  	struct ipath_ibdev *dev = to_idev(context->device);
  	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
  	unsigned long size = vma->vm_end - vma->vm_start;
  	struct ipath_mmap_info *ip, **pp;
  	int ret = -EINVAL;
  
  	/*
  	 * Search the device's list of objects waiting for a mmap call.
  	 * Normally, this list is very short since a call to create a
  	 * CQ, QP, or SRQ is soon followed by a call to mmap().
  	 */
  	spin_lock_irq(&dev->pending_lock);
  	for (pp = &dev->pending_mmaps; (ip = *pp); pp = &ip->next) {
  		/* Only the creator is allowed to mmap the object */
  		if (context != ip->context || (void *) offset != ip->obj)
  			continue;
  		/* Don't allow a mmap larger than the object. */
  		if (size > ip->size)
  			break;
  
  		*pp = ip->next;
  		spin_unlock_irq(&dev->pending_lock);
  
  		ret = remap_vmalloc_range(vma, ip->obj, 0);
  		if (ret)
  			goto done;
  		vma->vm_ops = &ipath_vm_ops;
  		vma->vm_private_data = ip;
  		ipath_vma_open(vma);
  		goto done;
  	}
  	spin_unlock_irq(&dev->pending_lock);
  done:
  	return ret;
  }
  