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#include <linux/shm.h>
  40
  41#include "rxe.h"
  42#include "rxe_loc.h"
  43#include "rxe_queue.h"
  44
  45void rxe_mmap_release(struct kref *ref)
  46{
  47        struct rxe_mmap_info *ip = container_of(ref,
  48                                        struct rxe_mmap_info, ref);
  49        struct rxe_dev *rxe = to_rdev(ip->context->device);
  50
  51        spin_lock_bh(&rxe->pending_lock);
  52
  53        if (!list_empty(&ip->pending_mmaps))
  54                list_del(&ip->pending_mmaps);
  55
  56        spin_unlock_bh(&rxe->pending_lock);
  57
  58        vfree(ip->obj);         /* buf */
  59        kfree(ip);
  60}
  61
  62/*
  63 * open and close keep track of how many times the memory region is mapped,
  64 * to avoid releasing it.
  65 */
  66static void rxe_vma_open(struct vm_area_struct *vma)
  67{
  68        struct rxe_mmap_info *ip = vma->vm_private_data;
  69
  70        kref_get(&ip->ref);
  71}
  72
  73static void rxe_vma_close(struct vm_area_struct *vma)
  74{
  75        struct rxe_mmap_info *ip = vma->vm_private_data;
  76
  77        kref_put(&ip->ref, rxe_mmap_release);
  78}
  79
  80static const struct vm_operations_struct rxe_vm_ops = {
  81        .open = rxe_vma_open,
  82        .close = rxe_vma_close,
  83};
  84
  85/**
  86 * rxe_mmap - create a new mmap region
  87 * @context: the IB user context of the process making the mmap() call
  88 * @vma: the VMA to be initialized
  89 * Return zero if the mmap is OK. Otherwise, return an errno.
  90 */
  91int rxe_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
  92{
  93        struct rxe_dev *rxe = to_rdev(context->device);
  94        unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
  95        unsigned long size = vma->vm_end - vma->vm_start;
  96        struct rxe_mmap_info *ip, *pp;
  97        int ret;
  98
  99        /*
 100         * Search the device's list of objects waiting for a mmap call.
 101         * Normally, this list is very short since a call to create a
 102         * CQ, QP, or SRQ is soon followed by a call to mmap().
 103         */
 104        spin_lock_bh(&rxe->pending_lock);
 105        list_for_each_entry_safe(ip, pp, &rxe->pending_mmaps, pending_mmaps) {
 106                if (context != ip->context || (__u64)offset != ip->info.offset)
 107                        continue;
 108
 109                /* Don't allow a mmap larger than the object. */
 110                if (size > ip->info.size) {
 111                        pr_err("mmap region is larger than the object!\n");
 112                        spin_unlock_bh(&rxe->pending_lock);
 113                        ret = -EINVAL;
 114                        goto done;
 115                }
 116
 117                goto found_it;
 118        }
 119        pr_warn("unable to find pending mmap info\n");
 120        spin_unlock_bh(&rxe->pending_lock);
 121        ret = -EINVAL;
 122        goto done;
 123
 124found_it:
 125        list_del_init(&ip->pending_mmaps);
 126        spin_unlock_bh(&rxe->pending_lock);
 127
 128        ret = remap_vmalloc_range(vma, ip->obj, 0);
 129        if (ret) {
 130                pr_err("err %d from remap_vmalloc_range\n", ret);
 131                goto done;
 132        }
 133
 134        vma->vm_ops = &rxe_vm_ops;
 135        vma->vm_private_data = ip;
 136        rxe_vma_open(vma);
 137done:
 138        return ret;
 139}
 140
 141/*
 142 * Allocate information for rxe_mmap
 143 */
 144struct rxe_mmap_info *rxe_create_mmap_info(struct rxe_dev *rxe,
 145                                           u32 size,
 146                                           struct ib_ucontext *context,
 147                                           void *obj)
 148{
 149        struct rxe_mmap_info *ip;
 150
 151        ip = kmalloc(sizeof(*ip), GFP_KERNEL);
 152        if (!ip)
 153                return NULL;
 154
 155        size = PAGE_ALIGN(size);
 156
 157        spin_lock_bh(&rxe->mmap_offset_lock);
 158
 159        if (rxe->mmap_offset == 0)
 160                rxe->mmap_offset = ALIGN(PAGE_SIZE, SHMLBA);
 161
 162        ip->info.offset = rxe->mmap_offset;
 163        rxe->mmap_offset += ALIGN(size, SHMLBA);
 164
 165        spin_unlock_bh(&rxe->mmap_offset_lock);
 166
 167        INIT_LIST_HEAD(&ip->pending_mmaps);
 168        ip->info.size = size;
 169        ip->context = context;
 170        ip->obj = obj;
 171        kref_init(&ip->ref);
 172
 173        return ip;
 174}
 175