1 // SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
2 /*
3 * Copyright(c) 2016 Intel Corporation.
4 */
5
6 #include <linux/slab.h>
7 #include <linux/vmalloc.h>
8 #include <linux/mm.h>
9 #include <rdma/uverbs_ioctl.h>
10 #include "mmap.h"
11
12 /**
13 * rvt_mmap_init - init link list and lock for mem map
14 * @rdi: rvt dev struct
15 */
rvt_mmap_init(struct rvt_dev_info * rdi)16 void rvt_mmap_init(struct rvt_dev_info *rdi)
17 {
18 INIT_LIST_HEAD(&rdi->pending_mmaps);
19 spin_lock_init(&rdi->pending_lock);
20 rdi->mmap_offset = PAGE_SIZE;
21 spin_lock_init(&rdi->mmap_offset_lock);
22 }
23
24 /**
25 * rvt_release_mmap_info - free mmap info structure
26 * @ref: a pointer to the kref within struct rvt_mmap_info
27 */
rvt_release_mmap_info(struct kref * ref)28 void rvt_release_mmap_info(struct kref *ref)
29 {
30 struct rvt_mmap_info *ip =
31 container_of(ref, struct rvt_mmap_info, ref);
32 struct rvt_dev_info *rdi = ib_to_rvt(ip->context->device);
33
34 spin_lock_irq(&rdi->pending_lock);
35 list_del(&ip->pending_mmaps);
36 spin_unlock_irq(&rdi->pending_lock);
37
38 vfree(ip->obj);
39 kfree(ip);
40 }
41
rvt_vma_open(struct vm_area_struct * vma)42 static void rvt_vma_open(struct vm_area_struct *vma)
43 {
44 struct rvt_mmap_info *ip = vma->vm_private_data;
45
46 kref_get(&ip->ref);
47 }
48
rvt_vma_close(struct vm_area_struct * vma)49 static void rvt_vma_close(struct vm_area_struct *vma)
50 {
51 struct rvt_mmap_info *ip = vma->vm_private_data;
52
53 kref_put(&ip->ref, rvt_release_mmap_info);
54 }
55
56 static const struct vm_operations_struct rvt_vm_ops = {
57 .open = rvt_vma_open,
58 .close = rvt_vma_close,
59 };
60
61 /**
62 * rvt_mmap - create a new mmap region
63 * @context: the IB user context of the process making the mmap() call
64 * @vma: the VMA to be initialized
65 *
66 * Return: zero if the mmap is OK. Otherwise, return an errno.
67 */
rvt_mmap(struct ib_ucontext * context,struct vm_area_struct * vma)68 int rvt_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
69 {
70 struct rvt_dev_info *rdi = ib_to_rvt(context->device);
71 unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
72 unsigned long size = vma->vm_end - vma->vm_start;
73 struct rvt_mmap_info *ip, *pp;
74 int ret = -EINVAL;
75
76 /*
77 * Search the device's list of objects waiting for a mmap call.
78 * Normally, this list is very short since a call to create a
79 * CQ, QP, or SRQ is soon followed by a call to mmap().
80 */
81 spin_lock_irq(&rdi->pending_lock);
82 list_for_each_entry_safe(ip, pp, &rdi->pending_mmaps,
83 pending_mmaps) {
84 /* Only the creator is allowed to mmap the object */
85 if (context != ip->context || (__u64)offset != ip->offset)
86 continue;
87 /* Don't allow a mmap larger than the object. */
88 if (size > ip->size)
89 break;
90
91 list_del_init(&ip->pending_mmaps);
92 spin_unlock_irq(&rdi->pending_lock);
93
94 ret = remap_vmalloc_range(vma, ip->obj, 0);
95 if (ret)
96 goto done;
97 vma->vm_ops = &rvt_vm_ops;
98 vma->vm_private_data = ip;
99 rvt_vma_open(vma);
100 goto done;
101 }
102 spin_unlock_irq(&rdi->pending_lock);
103 done:
104 return ret;
105 }
106
107 /**
108 * rvt_create_mmap_info - allocate information for hfi1_mmap
109 * @rdi: rvt dev struct
110 * @size: size in bytes to map
111 * @udata: user data (must be valid!)
112 * @obj: opaque pointer to a cq, wq etc
113 *
114 * Return: rvt_mmap struct on success, ERR_PTR on failure
115 */
rvt_create_mmap_info(struct rvt_dev_info * rdi,u32 size,struct ib_udata * udata,void * obj)116 struct rvt_mmap_info *rvt_create_mmap_info(struct rvt_dev_info *rdi, u32 size,
117 struct ib_udata *udata, void *obj)
118 {
119 struct rvt_mmap_info *ip;
120
121 if (!udata)
122 return ERR_PTR(-EINVAL);
123
124 ip = kmalloc_node(sizeof(*ip), GFP_KERNEL, rdi->dparms.node);
125 if (!ip)
126 return ERR_PTR(-ENOMEM);
127
128 size = PAGE_ALIGN(size);
129
130 spin_lock_irq(&rdi->mmap_offset_lock);
131 if (rdi->mmap_offset == 0)
132 rdi->mmap_offset = ALIGN(PAGE_SIZE, SHMLBA);
133 ip->offset = rdi->mmap_offset;
134 rdi->mmap_offset += ALIGN(size, SHMLBA);
135 spin_unlock_irq(&rdi->mmap_offset_lock);
136
137 INIT_LIST_HEAD(&ip->pending_mmaps);
138 ip->size = size;
139 ip->context =
140 container_of(udata, struct uverbs_attr_bundle, driver_udata)
141 ->context;
142 ip->obj = obj;
143 kref_init(&ip->ref);
144
145 return ip;
146 }
147
148 /**
149 * rvt_update_mmap_info - update a mem map
150 * @rdi: rvt dev struct
151 * @ip: mmap info pointer
152 * @size: size to grow by
153 * @obj: opaque pointer to cq, wq, etc.
154 */
rvt_update_mmap_info(struct rvt_dev_info * rdi,struct rvt_mmap_info * ip,u32 size,void * obj)155 void rvt_update_mmap_info(struct rvt_dev_info *rdi, struct rvt_mmap_info *ip,
156 u32 size, void *obj)
157 {
158 size = PAGE_ALIGN(size);
159
160 spin_lock_irq(&rdi->mmap_offset_lock);
161 if (rdi->mmap_offset == 0)
162 rdi->mmap_offset = PAGE_SIZE;
163 ip->offset = rdi->mmap_offset;
164 rdi->mmap_offset += size;
165 spin_unlock_irq(&rdi->mmap_offset_lock);
166
167 ip->size = size;
168 ip->obj = obj;
169 }
170