LXR linux/drivers/infiniband/hw/ipath/ipath

   1/*
   2 * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
   3 *
   4 * This software is available to you under a choice of one of two
   5 * licenses.  You may choose to be licensed under the terms of the GNU
   6 * General Public License (GPL) Version 2, available from the file
   7 * COPYING in the main directory of this source tree, or the
   8 * OpenIB.org BSD license below:
   9 *
  10 *     Redistribution and use in source and binary forms, with or
  11 *     without modification, are permitted provided that the following
  12 *     conditions are met:
  13 *
  14 *      - Redistributions of source code must retain the above
  15 *        copyright notice, this list of conditions and the following
  16 *        disclaimer.
  17 *
  18 *      - Redistributions in binary form must reproduce the above
  19 *        copyright notice, this list of conditions and the following
  20 *        disclaimer in the documentation and/or other materials
  21 *        provided with the distribution.
  22 *
  23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30 * SOFTWARE.
  31 */
  32
  33#include <linux/module.h>
  34#include <linux/vmalloc.h>
  35#include <linux/slab.h>
  36#include <linux/mm.h>
  37#include <linux/errno.h>
  38#include <asm/pgtable.h>
  39
  40#include "ipath_verbs.h"
  41
  42/**
  43 * ipath_release_mmap_info - free mmap info structure
  44 * @ref: a pointer to the kref within struct ipath_mmap_info
  45 */
  46void ipath_release_mmap_info(struct kref *ref)
  47{
  48        struct ipath_mmap_info *ip =
  49                container_of(ref, struct ipath_mmap_info, ref);
  50        struct ipath_ibdev *dev = to_idev(ip->context->device);
  51
  52        spin_lock_irq(&dev->pending_lock);
  53        list_del(&ip->pending_mmaps);
  54        spin_unlock_irq(&dev->pending_lock);
  55
  56        vfree(ip->obj);
  57        kfree(ip);
  58}
  59
  60/*
  61 * open and close keep track of how many times the CQ is mapped,
  62 * to avoid releasing it.
  63 */
  64static void ipath_vma_open(struct vm_area_struct *vma)
  65{
  66        struct ipath_mmap_info *ip = vma->vm_private_data;
  67
  68        kref_get(&ip->ref);
  69}
  70
  71static void ipath_vma_close(struct vm_area_struct *vma)
  72{
  73        struct ipath_mmap_info *ip = vma->vm_private_data;
  74
  75        kref_put(&ip->ref, ipath_release_mmap_info);
  76}
  77
  78static const struct vm_operations_struct ipath_vm_ops = {
  79        .open =     ipath_vma_open,
  80        .close =    ipath_vma_close,
  81};
  82
  83/**
  84 * ipath_mmap - create a new mmap region
  85 * @context: the IB user context of the process making the mmap() call
  86 * @vma: the VMA to be initialized
  87 * Return zero if the mmap is OK. Otherwise, return an errno.
  88 */
  89int ipath_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
  90{
  91        struct ipath_ibdev *dev = to_idev(context->device);
  92        unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
  93        unsigned long size = vma->vm_end - vma->vm_start;
  94        struct ipath_mmap_info *ip, *pp;
  95        int ret = -EINVAL;
  96
  97        /*
  98         * Search the device's list of objects waiting for a mmap call.
  99         * Normally, this list is very short since a call to create a
 100         * CQ, QP, or SRQ is soon followed by a call to mmap().
 101         */
 102        spin_lock_irq(&dev->pending_lock);
 103        list_for_each_entry_safe(ip, pp, &dev->pending_mmaps,
 104                                 pending_mmaps) {
 105                /* Only the creator is allowed to mmap the object */
 106                if (context != ip->context || (__u64) offset != ip->offset)
 107                        continue;
 108                /* Don't allow a mmap larger than the object. */
 109                if (size > ip->size)
 110                        break;
 111
 112                list_del_init(&ip->pending_mmaps);
 113                spin_unlock_irq(&dev->pending_lock);
 114
 115                ret = remap_vmalloc_range(vma, ip->obj, 0);
 116                if (ret)
 117                        goto done;
 118                vma->vm_ops = &ipath_vm_ops;
 119                vma->vm_private_data = ip;
 120                ipath_vma_open(vma);
 121                goto done;
 122        }
 123        spin_unlock_irq(&dev->pending_lock);
 124done:
 125        return ret;
 126}
 127
 128/*
 129 * Allocate information for ipath_mmap
 130 */
 131struct ipath_mmap_info *ipath_create_mmap_info(struct ipath_ibdev *dev,
 132                                               u32 size,
 133                                               struct ib_ucontext *context,
 134                                               void *obj) {
 135        struct ipath_mmap_info *ip;
 136
 137        ip = kmalloc(sizeof *ip, GFP_KERNEL);
 138        if (!ip)
 139                goto bail;
 140
 141        size = PAGE_ALIGN(size);
 142
 143        spin_lock_irq(&dev->mmap_offset_lock);
 144        if (dev->mmap_offset == 0)
 145                dev->mmap_offset = PAGE_SIZE;
 146        ip->offset = dev->mmap_offset;
 147        dev->mmap_offset += size;
 148        spin_unlock_irq(&dev->mmap_offset_lock);
 149
 150        INIT_LIST_HEAD(&ip->pending_mmaps);
 151        ip->size = size;
 152        ip->context = context;
 153        ip->obj = obj;
 154        kref_init(&ip->ref);
 155
 156bail:
 157        return ip;
 158}
 159
 160void ipath_update_mmap_info(struct ipath_ibdev *dev,
 161                            struct ipath_mmap_info *ip,
 162                            u32 size, void *obj) {
 163        size = PAGE_ALIGN(size);
 164
 165        spin_lock_irq(&dev->mmap_offset_lock);
 166        if (dev->mmap_offset == 0)
 167                dev->mmap_offset = PAGE_SIZE;
 168        ip->offset = dev->mmap_offset;
 169        dev->mmap_offset += size;
 170        spin_unlock_irq(&dev->mmap_offset_lock);
 171
 172        ip->size = size;
 173        ip->obj = obj;
 174}
 175