LXR linux/drivers/infiniband/sw/rxe/rxe

   1/*
   2 * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
   3 * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
   4 *
   5 * This software is available to you under a choice of one of two
   6 * licenses.  You may choose to be licensed under the terms of the GNU
   7 * General Public License (GPL) Version 2, available from the file
   8 * COPYING in the main directory of this source tree, or the
   9 * OpenIB.org BSD license below:
  10 *
  11 *     Redistribution and use in source and binary forms, with or
  12 *     without modification, are permitted provided that the following
  13 *     conditions are met:
  14 *
  15 *      - Redistributions of source code must retain the above
  16 *        copyright notice, this list of conditions and the following
  17 *        disclaimer.
  18 *
  19 *      - Redistributions in binary form must reproduce the above
  20 *        copyright notice, this list of conditions and the following
  21 *        disclaimer in the documentation and/or other materials
  22 *        provided with the distribution.
  23 *
  24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31 * SOFTWARE.
  32 */
  33
  34#include <linux/module.h>
  35#include <linux/vmalloc.h>
  36#include <linux/mm.h>
  37#include <linux/errno.h>
  38#include <asm/pgtable.h>
  39
  40#include "rxe.h"
  41#include "rxe_loc.h"
  42#include "rxe_queue.h"
  43
  44void rxe_mmap_release(struct kref *ref)
  45{
  46        struct rxe_mmap_info *ip = container_of(ref,
  47                                        struct rxe_mmap_info, ref);
  48        struct rxe_dev *rxe = to_rdev(ip->context->device);
  49
  50        spin_lock_bh(&rxe->pending_lock);
  51
  52        if (!list_empty(&ip->pending_mmaps))
  53                list_del(&ip->pending_mmaps);
  54
  55        spin_unlock_bh(&rxe->pending_lock);
  56
  57        vfree(ip->obj);         /* buf */
  58        kfree(ip);
  59}
  60
  61/*
  62 * open and close keep track of how many times the memory region is mapped,
  63 * to avoid releasing it.
  64 */
  65static void rxe_vma_open(struct vm_area_struct *vma)
  66{
  67        struct rxe_mmap_info *ip = vma->vm_private_data;
  68
  69        kref_get(&ip->ref);
  70}
  71
  72static void rxe_vma_close(struct vm_area_struct *vma)
  73{
  74        struct rxe_mmap_info *ip = vma->vm_private_data;
  75
  76        kref_put(&ip->ref, rxe_mmap_release);
  77}
  78
  79static struct vm_operations_struct rxe_vm_ops = {
  80        .open = rxe_vma_open,
  81        .close = rxe_vma_close,
  82};
  83
  84/**
  85 * rxe_mmap - create a new mmap region
  86 * @context: the IB user context of the process making the mmap() call
  87 * @vma: the VMA to be initialized
  88 * Return zero if the mmap is OK. Otherwise, return an errno.
  89 */
  90int rxe_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
  91{
  92        struct rxe_dev *rxe = to_rdev(context->device);
  93        unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
  94        unsigned long size = vma->vm_end - vma->vm_start;
  95        struct rxe_mmap_info *ip, *pp;
  96        int ret;
  97
  98        /*
  99         * Search the device's list of objects waiting for a mmap call.
 100         * Normally, this list is very short since a call to create a
 101         * CQ, QP, or SRQ is soon followed by a call to mmap().
 102         */
 103        spin_lock_bh(&rxe->pending_lock);
 104        list_for_each_entry_safe(ip, pp, &rxe->pending_mmaps, pending_mmaps) {
 105                if (context != ip->context || (__u64)offset != ip->info.offset)
 106                        continue;
 107
 108                /* Don't allow a mmap larger than the object. */
 109                if (size > ip->info.size) {
 110                        pr_err("mmap region is larger than the object!\n");
 111                        spin_unlock_bh(&rxe->pending_lock);
 112                        ret = -EINVAL;
 113                        goto done;
 114                }
 115
 116                goto found_it;
 117        }
 118        pr_warn("unable to find pending mmap info\n");
 119        spin_unlock_bh(&rxe->pending_lock);
 120        ret = -EINVAL;
 121        goto done;
 122
 123found_it:
 124        list_del_init(&ip->pending_mmaps);
 125        spin_unlock_bh(&rxe->pending_lock);
 126
 127        ret = remap_vmalloc_range(vma, ip->obj, 0);
 128        if (ret) {
 129                pr_err("err %d from remap_vmalloc_range\n", ret);
 130                goto done;
 131        }
 132
 133        vma->vm_ops = &rxe_vm_ops;
 134        vma->vm_private_data = ip;
 135        rxe_vma_open(vma);
 136done:
 137        return ret;
 138}
 139
 140/*
 141 * Allocate information for rxe_mmap
 142 */
 143struct rxe_mmap_info *rxe_create_mmap_info(struct rxe_dev *rxe,
 144                                           u32 size,
 145                                           struct ib_ucontext *context,
 146                                           void *obj)
 147{
 148        struct rxe_mmap_info *ip;
 149
 150        ip = kmalloc(sizeof(*ip), GFP_KERNEL);
 151        if (!ip)
 152                return NULL;
 153
 154        size = PAGE_ALIGN(size);
 155
 156        spin_lock_bh(&rxe->mmap_offset_lock);
 157
 158        if (rxe->mmap_offset == 0)
 159                rxe->mmap_offset = PAGE_SIZE;
 160
 161        ip->info.offset = rxe->mmap_offset;
 162        rxe->mmap_offset += size;
 163
 164        spin_unlock_bh(&rxe->mmap_offset_lock);
 165
 166        INIT_LIST_HEAD(&ip->pending_mmaps);
 167        ip->info.size = size;
 168        ip->context = context;
 169        ip->obj = obj;
 170        kref_init(&ip->ref);
 171
 172        return ip;
 173}
 174