LXR linux/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 */
  58void 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 */
  70void 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
  84static 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
  91static 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
  98static 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 */
 110int 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);
 145done:
 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 */
 158struct 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 = ALIGN(PAGE_SIZE, SHMLBA);
 174        ip->offset = rdi->mmap_offset;
 175        rdi->mmap_offset += ALIGN(size, SHMLBA);
 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 */
 194void 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}
 209