root/drivers/infiniband/sw/rxe/rxe_mmap.c

DEFINITIONS

1. rxe_mmap_release
2. rxe_vma_open
3. rxe_vma_close
4. rxe_mmap
5. rxe_create_mmap_info

   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 <rdma/uverbs_ioctl.h>
  40 
  41 #include "rxe.h"
  42 #include "rxe_loc.h"
  43 #include "rxe_queue.h"
  44 
  45 void 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  */
  66 static 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 
  73 static 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 
  80 static 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  */
  91 int 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 
 124 found_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);
 137 done:
 138         return ret;
 139 }
 140 
 141 /*
 142  * Allocate information for rxe_mmap
 143  */
 144 struct rxe_mmap_info *rxe_create_mmap_info(struct rxe_dev *rxe, u32 size,
 145                                            struct ib_udata *udata, void *obj)
 146 {
 147         struct rxe_mmap_info *ip;
 148 
 149         if (!udata)
 150                 return ERR_PTR(-EINVAL);
 151 
 152         ip = kmalloc(sizeof(*ip), GFP_KERNEL);
 153         if (!ip)
 154                 return ERR_PTR(-ENOMEM);
 155 
 156         size = PAGE_ALIGN(size);
 157 
 158         spin_lock_bh(&rxe->mmap_offset_lock);
 159 
 160         if (rxe->mmap_offset == 0)
 161                 rxe->mmap_offset = ALIGN(PAGE_SIZE, SHMLBA);
 162 
 163         ip->info.offset = rxe->mmap_offset;
 164         rxe->mmap_offset += ALIGN(size, SHMLBA);
 165 
 166         spin_unlock_bh(&rxe->mmap_offset_lock);
 167 
 168         INIT_LIST_HEAD(&ip->pending_mmaps);
 169         ip->info.size = size;
 170         ip->context =
 171                 container_of(udata, struct uverbs_attr_bundle, driver_udata)
 172                         ->context;
 173         ip->obj = obj;
 174         kref_init(&ip->ref);
 175 
 176         return ip;
 177 }