1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (C) 2017 Google, Inc.
4 */
5
6 #ifndef _LINUX_BINDER_ALLOC_H
7 #define _LINUX_BINDER_ALLOC_H
8
9 #include <linux/rbtree.h>
10 #include <linux/list.h>
11 #include <linux/mm.h>
12 #include <linux/rtmutex.h>
13 #include <linux/vmalloc.h>
14 #include <linux/slab.h>
15 #include <linux/list_lru.h>
16 #include <uapi/linux/android/binder.h>
17
18 extern struct list_lru binder_alloc_lru;
19 struct binder_transaction;
20
21 /**
22 * struct binder_buffer - buffer used for binder transactions
23 * @entry: entry alloc->buffers
24 * @rb_node: node for allocated_buffers/free_buffers rb trees
25 * @free: %true if buffer is free
26 * @allow_user_free: %true if user is allowed to free buffer
27 * @async_transaction: %true if buffer is in use for an async txn
28 * @debug_id: unique ID for debugging
29 * @transaction: pointer to associated struct binder_transaction
30 * @target_node: struct binder_node associated with this buffer
31 * @data_size: size of @transaction data
32 * @offsets_size: size of array of offsets
33 * @extra_buffers_size: size of space for other objects (like sg lists)
34 * @user_data: user pointer to base of buffer space
35 *
36 * Bookkeeping structure for binder transaction buffers
37 */
38 struct binder_buffer {
39 struct list_head entry; /* free and allocated entries by address */
40 struct rb_node rb_node; /* free entry by size or allocated entry */
41 /* by address */
42 unsigned free:1;
43 unsigned allow_user_free:1;
44 unsigned async_transaction:1;
45 unsigned debug_id:29;
46
47 struct binder_transaction *transaction;
48
49 struct binder_node *target_node;
50 size_t data_size;
51 size_t offsets_size;
52 size_t extra_buffers_size;
53 void __user *user_data;
54 };
55
56 /**
57 * struct binder_lru_page - page object used for binder shrinker
58 * @page_ptr: pointer to physical page in mmap'd space
59 * @lru: entry in binder_alloc_lru
60 * @alloc: binder_alloc for a proc
61 */
62 struct binder_lru_page {
63 struct list_head lru;
64 struct page *page_ptr;
65 struct binder_alloc *alloc;
66 };
67
68 /**
69 * struct binder_alloc - per-binder proc state for binder allocator
70 * @vma: vm_area_struct passed to mmap_handler
71 * (invarient after mmap)
72 * @tsk: tid for task that called init for this proc
73 * (invariant after init)
74 * @vma_vm_mm: copy of vma->vm_mm (invarient after mmap)
75 * @buffer: base of per-proc address space mapped via mmap
76 * @buffers: list of all buffers for this proc
77 * @free_buffers: rb tree of buffers available for allocation
78 * sorted by size
79 * @allocated_buffers: rb tree of allocated buffers sorted by address
80 * @free_async_space: VA space available for async buffers. This is
81 * initialized at mmap time to 1/2 the full VA space
82 * @pages: array of binder_lru_page
83 * @buffer_size: size of address space specified via mmap
84 * @pid: pid for associated binder_proc (invariant after init)
85 * @pages_high: high watermark of offset in @pages
86 *
87 * Bookkeeping structure for per-proc address space management for binder
88 * buffers. It is normally initialized during binder_init() and binder_mmap()
89 * calls. The address space is used for both user-visible buffers and for
90 * struct binder_buffer objects used to track the user buffers
91 */
92 struct binder_alloc {
93 struct mutex mutex;
94 struct vm_area_struct *vma;
95 struct mm_struct *vma_vm_mm;
96 void __user *buffer;
97 struct list_head buffers;
98 struct rb_root free_buffers;
99 struct rb_root allocated_buffers;
100 size_t free_async_space;
101 struct binder_lru_page *pages;
102 size_t buffer_size;
103 uint32_t buffer_free;
104 int pid;
105 size_t pages_high;
106 };
107
108 #ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST
109 void binder_selftest_alloc(struct binder_alloc *alloc);
110 #else
111 static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
112 #endif
113 enum lru_status binder_alloc_free_page(struct list_head *item,
114 struct list_lru_one *lru,
115 spinlock_t *lock, void *cb_arg);
116 extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
117 size_t data_size,
118 size_t offsets_size,
119 size_t extra_buffers_size,
120 int is_async);
121 extern void binder_alloc_init(struct binder_alloc *alloc);
122 extern int binder_alloc_shrinker_init(void);
123 extern void binder_alloc_vma_close(struct binder_alloc *alloc);
124 extern struct binder_buffer *
125 binder_alloc_prepare_to_free(struct binder_alloc *alloc,
126 uintptr_t user_ptr);
127 extern void binder_alloc_free_buf(struct binder_alloc *alloc,
128 struct binder_buffer *buffer);
129 extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
130 struct vm_area_struct *vma);
131 extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
132 extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
133 extern void binder_alloc_print_allocated(struct seq_file *m,
134 struct binder_alloc *alloc);
135 void binder_alloc_print_pages(struct seq_file *m,
136 struct binder_alloc *alloc);
137
138 /**
139 * binder_alloc_get_free_async_space() - get free space available for async
140 * @alloc: binder_alloc for this proc
141 *
142 * Return: the bytes remaining in the address-space for async transactions
143 */
144 static inline size_t
145 binder_alloc_get_free_async_space(struct binder_alloc *alloc)
146 {
147 size_t free_async_space;
148
149 mutex_lock(&alloc->mutex);
150 free_async_space = alloc->free_async_space;
151 mutex_unlock(&alloc->mutex);
152 return free_async_space;
153 }
154
155 unsigned long
156 binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
157 struct binder_buffer *buffer,
158 binder_size_t buffer_offset,
159 const void __user *from,
160 size_t bytes);
161
162 int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
163 struct binder_buffer *buffer,
164 binder_size_t buffer_offset,
165 void *src,
166 size_t bytes);
167
168 int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
169 void *dest,
170 struct binder_buffer *buffer,
171 binder_size_t buffer_offset,
172 size_t bytes);
173
174 #endif /* _LINUX_BINDER_ALLOC_H */
175