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 */
16void 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 */
28void 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
42static 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
49static 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
56static 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 */
68int 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);
103done:
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 */
116struct 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 */
155void 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