Logo Search packages:      
Sourcecode: linux version File versions  Download package

ipath_mmap.c

/*
 * Copyright (c) 2006, 2007 QLogic Corporation. 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);
      struct ipath_ibdev *dev = to_idev(ip->context->device);

      spin_lock_irq(&dev->pending_lock);
      list_del(&ip->pending_mmaps);
      spin_unlock_irq(&dev->pending_lock);

      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);
}

static void ipath_vma_close(struct vm_area_struct *vma)
{
      struct ipath_mmap_info *ip = vma->vm_private_data;

      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);
      list_for_each_entry_safe(ip, pp, &dev->pending_mmaps,
                         pending_mmaps) {
            /* Only the creator is allowed to mmap the object */
            if (context != ip->context || (__u64) offset != ip->offset)
                  continue;
            /* Don't allow a mmap larger than the object. */
            if (size > ip->size)
                  break;

            list_del_init(&ip->pending_mmaps);
            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;
}

/*
 * Allocate information for ipath_mmap
 */
struct ipath_mmap_info *ipath_create_mmap_info(struct ipath_ibdev *dev,
                                     u32 size,
                                     struct ib_ucontext *context,
                                     void *obj) {
      struct ipath_mmap_info *ip;

      ip = kmalloc(sizeof *ip, GFP_KERNEL);
      if (!ip)
            goto bail;

      size = PAGE_ALIGN(size);

      spin_lock_irq(&dev->mmap_offset_lock);
      if (dev->mmap_offset == 0)
            dev->mmap_offset = PAGE_SIZE;
      ip->offset = dev->mmap_offset;
      dev->mmap_offset += size;
      spin_unlock_irq(&dev->mmap_offset_lock);

      INIT_LIST_HEAD(&ip->pending_mmaps);
      ip->size = size;
      ip->context = context;
      ip->obj = obj;
      kref_init(&ip->ref);

bail:
      return ip;
}

void ipath_update_mmap_info(struct ipath_ibdev *dev,
                      struct ipath_mmap_info *ip,
                      u32 size, void *obj) {
      size = PAGE_ALIGN(size);

      spin_lock_irq(&dev->mmap_offset_lock);
      if (dev->mmap_offset == 0)
            dev->mmap_offset = PAGE_SIZE;
      ip->offset = dev->mmap_offset;
      dev->mmap_offset += size;
      spin_unlock_irq(&dev->mmap_offset_lock);

      ip->size = size;
      ip->obj = obj;
}

Generated by  Doxygen 1.6.0   Back to index