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/module.h>
8 #include <linux/vmalloc.h>
9 #include <linux/mm.h>
10 #include <linux/errno.h>
11 #include <rdma/uverbs_ioctl.h>
12
13 #include "rxe.h"
14 #include "rxe_loc.h"
15 #include "rxe_queue.h"
16
rxe_mmap_release(struct kref * ref)17 void rxe_mmap_release(struct kref *ref)
18 {
19 struct rxe_mmap_info *ip = container_of(ref,
20 struct rxe_mmap_info, ref);
21 struct rxe_dev *rxe = to_rdev(ip->context->device);
22
23 spin_lock_bh(&rxe->pending_lock);
24
25 if (!list_empty(&ip->pending_mmaps))
26 list_del(&ip->pending_mmaps);
27
28 spin_unlock_bh(&rxe->pending_lock);
29
30 vfree(ip->obj); /* buf */
31 kfree(ip);
32 }
33
34 /*
35 * open and close keep track of how many times the memory region is mapped,
36 * to avoid releasing it.
37 */
rxe_vma_open(struct vm_area_struct * vma)38 static void rxe_vma_open(struct vm_area_struct *vma)
39 {
40 struct rxe_mmap_info *ip = vma->vm_private_data;
41
42 kref_get(&ip->ref);
43 }
44
rxe_vma_close(struct vm_area_struct * vma)45 static void rxe_vma_close(struct vm_area_struct *vma)
46 {
47 struct rxe_mmap_info *ip = vma->vm_private_data;
48
49 kref_put(&ip->ref, rxe_mmap_release);
50 }
51
52 static const struct vm_operations_struct rxe_vm_ops = {
53 .open = rxe_vma_open,
54 .close = rxe_vma_close,
55 };
56
57 /**
58 * rxe_mmap - create a new mmap region
59 * @context: the IB user context of the process making the mmap() call
60 * @vma: the VMA to be initialized
61 * Return zero if the mmap is OK. Otherwise, return an errno.
62 */
rxe_mmap(struct ib_ucontext * context,struct vm_area_struct * vma)63 int rxe_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
64 {
65 struct rxe_dev *rxe = to_rdev(context->device);
66 unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
67 unsigned long size = vma->vm_end - vma->vm_start;
68 struct rxe_mmap_info *ip, *pp;
69 int ret;
70
71 /*
72 * Search the device's list of objects waiting for a mmap call.
73 * Normally, this list is very short since a call to create a
74 * CQ, QP, or SRQ is soon followed by a call to mmap().
75 */
76 spin_lock_bh(&rxe->pending_lock);
77 list_for_each_entry_safe(ip, pp, &rxe->pending_mmaps, pending_mmaps) {
78 if (context != ip->context || (__u64)offset != ip->info.offset)
79 continue;
80
81 /* Don't allow a mmap larger than the object. */
82 if (size > ip->info.size) {
83 pr_err("mmap region is larger than the object!\n");
84 spin_unlock_bh(&rxe->pending_lock);
85 ret = -EINVAL;
86 goto done;
87 }
88
89 goto found_it;
90 }
91 pr_warn("unable to find pending mmap info\n");
92 spin_unlock_bh(&rxe->pending_lock);
93 ret = -EINVAL;
94 goto done;
95
96 found_it:
97 list_del_init(&ip->pending_mmaps);
98 spin_unlock_bh(&rxe->pending_lock);
99
100 ret = remap_vmalloc_range(vma, ip->obj, 0);
101 if (ret) {
102 pr_err("err %d from remap_vmalloc_range\n", ret);
103 goto done;
104 }
105
106 vma->vm_ops = &rxe_vm_ops;
107 vma->vm_private_data = ip;
108 rxe_vma_open(vma);
109 done:
110 return ret;
111 }
112
113 /*
114 * Allocate information for rxe_mmap
115 */
rxe_create_mmap_info(struct rxe_dev * rxe,u32 size,struct ib_udata * udata,void * obj)116 struct rxe_mmap_info *rxe_create_mmap_info(struct rxe_dev *rxe, u32 size,
117 struct ib_udata *udata, void *obj)
118 {
119 struct rxe_mmap_info *ip;
120
121 if (!udata)
122 return ERR_PTR(-EINVAL);
123
124 ip = kmalloc(sizeof(*ip), GFP_KERNEL);
125 if (!ip)
126 return ERR_PTR(-ENOMEM);
127
128 size = PAGE_ALIGN(size);
129
130 spin_lock_bh(&rxe->mmap_offset_lock);
131
132 if (rxe->mmap_offset == 0)
133 rxe->mmap_offset = ALIGN(PAGE_SIZE, SHMLBA);
134
135 ip->info.offset = rxe->mmap_offset;
136 rxe->mmap_offset += ALIGN(size, SHMLBA);
137
138 spin_unlock_bh(&rxe->mmap_offset_lock);
139
140 INIT_LIST_HEAD(&ip->pending_mmaps);
141 ip->info.size = size;
142 ip->context =
143 container_of(udata, struct uverbs_attr_bundle, driver_udata)
144 ->context;
145 ip->obj = obj;
146 kref_init(&ip->ref);
147
148 return ip;
149 }
150