drivers/infiniband/sw/rxe/rxe_mmap.c

   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
  44 void 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  */
  65 static 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
  72 static 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
  79 static const 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  */
  90 int 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
 123 found_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);
 136 done:
 137         return ret;
 138 }
 139
 140 /*
 141  * Allocate information for rxe_mmap
 142  */
 143 struct 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 = ALIGN(PAGE_SIZE, SHMLBA);
 160
 161         ip->info.offset = rxe->mmap_offset;
 162         rxe->mmap_offset += ALIGN(size, SHMLBA);
 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 }