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_dev(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_dev(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_dev(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}
149