linux-stable-rt/drivers/infiniband/hw/ipath/ipath_mmap.c

122 lines
3.6 KiB
C

/*
* 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;
}