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/mm.h>
  36#include <linux/errno.h>
  37#include <asm/pgtable.h>
  38
  39#include "ipath_verbs.h"
  40
  41/**
  42 * ipath_release_mmap_info - free mmap info structure
  43 * @ref: a pointer to the kref within struct ipath_mmap_info
  44 */
  45void ipath_release_mmap_info(struct kref *ref)
  46{
  47        struct ipath_mmap_info *ip =
  48                container_of(ref, struct ipath_mmap_info, ref);
  49        struct ipath_ibdev *dev = to_idev(ip->context->device);
  50
  51        spin_lock_irq(&dev->pending_lock);
  52        list_del(&ip->pending_mmaps);
  53        spin_unlock_irq(&dev->pending_lock);
  54
  55        vfree(ip->obj);
  56        kfree(ip);
  57}
  58
  59/*
  60 * open and close keep track of how many times the CQ is mapped,
  61 * to avoid releasing it.
  62 */
  63static void ipath_vma_open(struct vm_area_struct *vma)
  64{
  65        struct ipath_mmap_info *ip = vma->vm_private_data;
  66
  67        kref_get(&ip->ref);
  68}
  69
  70static void ipath_vma_close(struct vm_area_struct *vma)
  71{
  72        struct ipath_mmap_info *ip = vma->vm_private_data;
  73
  74        kref_put(&ip->ref, ipath_release_mmap_info);
  75}
  76
  77static const struct vm_operations_struct ipath_vm_ops = {
  78        .open =     ipath_vma_open,
  79        .close =    ipath_vma_close,
  80};
  81
  82/**
  83 * ipath_mmap - create a new mmap region
  84 * @context: the IB user context of the process making the mmap() call
  85 * @vma: the VMA to be initialized
  86 * Return zero if the mmap is OK. Otherwise, return an errno.
  87 */
  88int ipath_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
  89{
  90        struct ipath_ibdev *dev = to_idev(context->device);
  91        unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
  92        unsigned long size = vma->vm_end - vma->vm_start;
  93        struct ipath_mmap_info *ip, *pp;
  94        int ret = -EINVAL;
  95
  96        /*
  97         * Search the device's list of objects waiting for a mmap call.
  98         * Normally, this list is very short since a call to create a
  99         * CQ, QP, or SRQ is soon followed by a call to mmap().
 100         */
 101        spin_lock_irq(&dev->pending_lock);
 102        list_for_each_entry_safe(ip, pp, &dev->pending_mmaps,
 103                                 pending_mmaps) {
 104                /* Only the creator is allowed to mmap the object */
 105                if (context != ip->context || (__u64) offset != ip->offset)
 106                        continue;
 107                /* Don't allow a mmap larger than the object. */
 108                if (size > ip->size)
 109                        break;
 110
 111                list_del_init(&ip->pending_mmaps);
 112                spin_unlock_irq(&dev->pending_lock);
 113
 114                ret = remap_vmalloc_range(vma, ip->obj, 0);
 115                if (ret)
 116                        goto done;
 117                vma->vm_ops = &ipath_vm_ops;
 118                vma->vm_private_data = ip;
 119                ipath_vma_open(vma);
 120                goto done;
 121        }
 122        spin_unlock_irq(&dev->pending_lock);
 123done:
 124        return ret;
 125}
 126
 127/*
 128 * Allocate information for ipath_mmap
 129 */
 130struct ipath_mmap_info *ipath_create_mmap_info(struct ipath_ibdev *dev,
 131                                               u32 size,
 132                                               struct ib_ucontext *context,
 133                                               void *obj) {
 134        struct ipath_mmap_info *ip;
 135
 136        ip = kmalloc(sizeof *ip, GFP_KERNEL);
 137        if (!ip)
 138                goto bail;
 139
 140        size = PAGE_ALIGN(size);
 141
 142        spin_lock_irq(&dev->mmap_offset_lock);
 143        if (dev->mmap_offset == 0)
 144                dev->mmap_offset = PAGE_SIZE;
 145        ip->offset = dev->mmap_offset;
 146        dev->mmap_offset += size;
 147        spin_unlock_irq(&dev->mmap_offset_lock);
 148
 149        INIT_LIST_HEAD(&ip->pending_mmaps);
 150        ip->size = size;
 151        ip->context = context;
 152        ip->obj = obj;
 153        kref_init(&ip->ref);
 154
 155bail:
 156        return ip;
 157}
 158
 159void ipath_update_mmap_info(struct ipath_ibdev *dev,
 160                            struct ipath_mmap_info *ip,
 161                            u32 size, void *obj) {
 162        size = PAGE_ALIGN(size);
 163
 164        spin_lock_irq(&dev->mmap_offset_lock);
 165        if (dev->mmap_offset == 0)
 166                dev->mmap_offset = PAGE_SIZE;
 167        ip->offset = dev->mmap_offset;
 168        dev->mmap_offset += size;
 169        spin_unlock_irq(&dev->mmap_offset_lock);
 170
 171        ip->size = size;
 172        ip->obj = obj;
 173}
 174