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