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