drivers/infiniband/sw/rdmavt/mmap.c

   1 /*
   2  * Copyright(c) 2016 Intel Corporation.
   3  *
   4  * This file is provided under a dual BSD/GPLv2 license.  When using or
   5  * redistributing this file, you may do so under either license.
   6  *
   7  * GPL LICENSE SUMMARY
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of version 2 of the GNU General Public License as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * BSD LICENSE
  19  *
  20  * Redistribution and use in source and binary forms, with or without
  21  * modification, are permitted provided that the following conditions
  22  * are met:
  23  *
  24  *  - Redistributions of source code must retain the above copyright
  25  *    notice, this list of conditions and the following disclaimer.
  26  *  - Redistributions in binary form must reproduce the above copyright
  27  *    notice, this list of conditions and the following disclaimer in
  28  *    the documentation and/or other materials provided with the
  29  *    distribution.
  30  *  - Neither the name of Intel Corporation nor the names of its
  31  *    contributors may be used to endorse or promote products derived
  32  *    from this software without specific prior written permission.
  33  *
  34  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  35  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  36  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  37  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  38  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  39  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  40  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  41  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  42  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  43  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  44  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  45  *
  46  */
  47
  48 #include <linux/slab.h>
  49 #include <linux/vmalloc.h>
  50 #include <linux/mm.h>
  51 #include <asm/pgtable.h>
  52 #include "mmap.h"
  53
  54 /**
  55  * rvt_mmap_init - init link list and lock for mem map
  56  * @rdi: rvt dev struct
  57  */
  58 void rvt_mmap_init(struct rvt_dev_info *rdi)
  59 {
  60         INIT_LIST_HEAD(&rdi->pending_mmaps);
  61         spin_lock_init(&rdi->pending_lock);
  62         rdi->mmap_offset = PAGE_SIZE;
  63         spin_lock_init(&rdi->mmap_offset_lock);
  64 }
  65
  66 /**
  67  * rvt_release_mmap_info - free mmap info structure
  68  * @ref: a pointer to the kref within struct rvt_mmap_info
  69  */
  70 void rvt_release_mmap_info(struct kref *ref)
  71 {
  72         struct rvt_mmap_info *ip =
  73                 container_of(ref, struct rvt_mmap_info, ref);
  74         struct rvt_dev_info *rdi = ib_to_rvt(ip->context->device);
  75
  76         spin_lock_irq(&rdi->pending_lock);
  77         list_del(&ip->pending_mmaps);
  78         spin_unlock_irq(&rdi->pending_lock);
  79
  80         vfree(ip->obj);
  81         kfree(ip);
  82 }
  83
  84 static void rvt_vma_open(struct vm_area_struct *vma)
  85 {
  86         struct rvt_mmap_info *ip = vma->vm_private_data;
  87
  88         kref_get(&ip->ref);
  89 }
  90
  91 static void rvt_vma_close(struct vm_area_struct *vma)
  92 {
  93         struct rvt_mmap_info *ip = vma->vm_private_data;
  94
  95         kref_put(&ip->ref, rvt_release_mmap_info);
  96 }
  97
  98 static const struct vm_operations_struct rvt_vm_ops = {
  99         .open = rvt_vma_open,
 100         .close = rvt_vma_close,
 101 };
 102
 103 /**
 104  * rvt_mmap - create a new mmap region
 105  * @context: the IB user context of the process making the mmap() call
 106  * @vma: the VMA to be initialized
 107  *
 108  * Return: zero if the mmap is OK. Otherwise, return an errno.
 109  */
 110 int rvt_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
 111 {
 112         struct rvt_dev_info *rdi = ib_to_rvt(context->device);
 113         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 114         unsigned long size = vma->vm_end - vma->vm_start;
 115         struct rvt_mmap_info *ip, *pp;
 116         int ret = -EINVAL;
 117
 118         /*
 119          * Search the device's list of objects waiting for a mmap call.
 120          * Normally, this list is very short since a call to create a
 121          * CQ, QP, or SRQ is soon followed by a call to mmap().
 122          */
 123         spin_lock_irq(&rdi->pending_lock);
 124         list_for_each_entry_safe(ip, pp, &rdi->pending_mmaps,
 125                                  pending_mmaps) {
 126                 /* Only the creator is allowed to mmap the object */
 127                 if (context != ip->context || (__u64)offset != ip->offset)
 128                         continue;
 129                 /* Don't allow a mmap larger than the object. */
 130                 if (size > ip->size)
 131                         break;
 132
 133                 list_del_init(&ip->pending_mmaps);
 134                 spin_unlock_irq(&rdi->pending_lock);
 135
 136                 ret = remap_vmalloc_range(vma, ip->obj, 0);
 137                 if (ret)
 138                         goto done;
 139                 vma->vm_ops = &rvt_vm_ops;
 140                 vma->vm_private_data = ip;
 141                 rvt_vma_open(vma);
 142                 goto done;
 143         }
 144         spin_unlock_irq(&rdi->pending_lock);
 145 done:
 146         return ret;
 147 }
 148
 149 /**
 150  * rvt_create_mmap_info - allocate information for hfi1_mmap
 151  * @rdi: rvt dev struct
 152  * @size: size in bytes to map
 153  * @context: user context
 154  * @obj: opaque pointer to a cq, wq etc
 155  *
 156  * Return: rvt_mmap struct on success
 157  */
 158 struct rvt_mmap_info *rvt_create_mmap_info(struct rvt_dev_info *rdi,
 159                                            u32 size,
 160                                            struct ib_ucontext *context,
 161                                            void *obj)
 162 {
 163         struct rvt_mmap_info *ip;
 164
 165         ip = kmalloc_node(sizeof(*ip), GFP_KERNEL, rdi->dparms.node);
 166         if (!ip)
 167                 return ip;
 168
 169         size = PAGE_ALIGN(size);
 170
 171         spin_lock_irq(&rdi->mmap_offset_lock);
 172         if (rdi->mmap_offset == 0)
 173                 rdi->mmap_offset = PAGE_SIZE;
 174         ip->offset = rdi->mmap_offset;
 175         rdi->mmap_offset += size;
 176         spin_unlock_irq(&rdi->mmap_offset_lock);
 177
 178         INIT_LIST_HEAD(&ip->pending_mmaps);
 179         ip->size = size;
 180         ip->context = context;
 181         ip->obj = obj;
 182         kref_init(&ip->ref);
 183
 184         return ip;
 185 }
 186
 187 /**
 188  * rvt_update_mmap_info - update a mem map
 189  * @rdi: rvt dev struct
 190  * @ip: mmap info pointer
 191  * @size: size to grow by
 192  * @obj: opaque pointer to cq, wq, etc.
 193  */
 194 void rvt_update_mmap_info(struct rvt_dev_info *rdi, struct rvt_mmap_info *ip,
 195                           u32 size, void *obj)
 196 {
 197         size = PAGE_ALIGN(size);
 198
 199         spin_lock_irq(&rdi->mmap_offset_lock);
 200         if (rdi->mmap_offset == 0)
 201                 rdi->mmap_offset = PAGE_SIZE;
 202         ip->offset = rdi->mmap_offset;
 203         rdi->mmap_offset += size;
 204         spin_unlock_irq(&rdi->mmap_offset_lock);
 205
 206         ip->size = size;
 207         ip->obj = obj;
 208 }