1// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
  2/*
  3 * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
  4 * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
  5 */
  6
  7#include <linux/vmalloc.h>
  8#include <linux/mm.h>
  9#include <linux/errno.h>
 10#include <rdma/uverbs_ioctl.h>
 11
 12#include "rxe.h"
 13#include "rxe_loc.h"
 14#include "rxe_queue.h"
 15
 16void rxe_mmap_release(struct kref *ref)
 17{
 18	struct rxe_mmap_info *ip = container_of(ref,
 19					struct rxe_mmap_info, ref);
 20	struct rxe_dev *rxe = to_rdev(ip->context->device);
 21
 22	spin_lock_bh(&rxe->pending_lock);
 23
 24	if (!list_empty(&ip->pending_mmaps))
 25		list_del(&ip->pending_mmaps);
 26
 27	spin_unlock_bh(&rxe->pending_lock);
 28
 29	vfree(ip->obj);		/* buf */
 30	kfree(ip);
 31}
 32
 33/*
 34 * open and close keep track of how many times the memory region is mapped,
 35 * to avoid releasing it.
 36 */
 37static void rxe_vma_open(struct vm_area_struct *vma)
 38{
 39	struct rxe_mmap_info *ip = vma->vm_private_data;
 40
 41	kref_get(&ip->ref);
 42}
 43
 44static void rxe_vma_close(struct vm_area_struct *vma)
 45{
 46	struct rxe_mmap_info *ip = vma->vm_private_data;
 47
 48	kref_put(&ip->ref, rxe_mmap_release);
 49}
 50
 51static const struct vm_operations_struct rxe_vm_ops = {
 52	.open = rxe_vma_open,
 53	.close = rxe_vma_close,
 54};
 55
 56/**
 57 * rxe_mmap - create a new mmap region
 58 * @context: the IB user context of the process making the mmap() call
 59 * @vma: the VMA to be initialized
 60 * Return zero if the mmap is OK. Otherwise, return an errno.
 61 */
 62int rxe_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
 63{
 64	struct rxe_dev *rxe = to_rdev(context->device);
 65	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 66	unsigned long size = vma->vm_end - vma->vm_start;
 67	struct rxe_mmap_info *ip, *pp;
 68	int ret;
 69
 70	/*
 71	 * Search the device's list of objects waiting for a mmap call.
 72	 * Normally, this list is very short since a call to create a
 73	 * CQ, QP, or SRQ is soon followed by a call to mmap().
 74	 */
 75	spin_lock_bh(&rxe->pending_lock);
 76	list_for_each_entry_safe(ip, pp, &rxe->pending_mmaps, pending_mmaps) {
 77		if (context != ip->context || (__u64)offset != ip->info.offset)
 78			continue;
 79
 80		/* Don't allow a mmap larger than the object. */
 81		if (size > ip->info.size) {
 82			rxe_dbg(rxe, "mmap region is larger than the object!\n");
 83			spin_unlock_bh(&rxe->pending_lock);
 84			ret = -EINVAL;
 85			goto done;
 86		}
 87
 88		goto found_it;
 89	}
 90	rxe_dbg(rxe, "unable to find pending mmap info\n");
 91	spin_unlock_bh(&rxe->pending_lock);
 92	ret = -EINVAL;
 93	goto done;
 94
 95found_it:
 96	list_del_init(&ip->pending_mmaps);
 97	spin_unlock_bh(&rxe->pending_lock);
 98
 99	ret = remap_vmalloc_range(vma, ip->obj, 0);
100	if (ret) {
101		rxe_dbg(rxe, "err %d from remap_vmalloc_range\n", ret);
102		goto done;
103	}
104
105	vma->vm_ops = &rxe_vm_ops;
106	vma->vm_private_data = ip;
107	rxe_vma_open(vma);
108done:
109	return ret;
110}
111
112/*
113 * Allocate information for rxe_mmap
114 */
115struct rxe_mmap_info *rxe_create_mmap_info(struct rxe_dev *rxe, u32 size,
116					   struct ib_udata *udata, void *obj)
117{
118	struct rxe_mmap_info *ip;
119
120	if (!udata)
121		return ERR_PTR(-EINVAL);
122
123	ip = kmalloc(sizeof(*ip), GFP_KERNEL);
124	if (!ip)
125		return ERR_PTR(-ENOMEM);
126
127	size = PAGE_ALIGN(size);
128
129	spin_lock_bh(&rxe->mmap_offset_lock);
130
131	if (rxe->mmap_offset == 0)
132		rxe->mmap_offset = ALIGN(PAGE_SIZE, SHMLBA);
133
134	ip->info.offset = rxe->mmap_offset;
135	rxe->mmap_offset += ALIGN(size, SHMLBA);
136
137	spin_unlock_bh(&rxe->mmap_offset_lock);
138
139	INIT_LIST_HEAD(&ip->pending_mmaps);
140	ip->info.size = size;
141	ip->context =
142		container_of(udata, struct uverbs_attr_bundle, driver_udata)
143			->context;
144	ip->obj = obj;
145	kref_init(&ip->ref);
146
147	return ip;
148}