1/*
2 * Copyright (C) 2017 Google, Inc.
3 *
4 * This software is licensed under the terms of the GNU General Public
5 * License version 2, as published by the Free Software Foundation, and
6 * may be copied, distributed, and modified under those terms.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 */
14
15#ifndef _LINUX_BINDER_ALLOC_H
16#define _LINUX_BINDER_ALLOC_H
17
18#include <linux/rbtree.h>
19#include <linux/list.h>
20#include <linux/mm.h>
21#include <linux/rtmutex.h>
22#include <linux/vmalloc.h>
23#include <linux/slab.h>
24#include <linux/list_lru.h>
25#include <uapi/linux/android/binder.h>
26
27extern struct list_lru binder_alloc_lru;
28struct binder_transaction;
29
30/**
31 * struct binder_buffer - buffer used for binder transactions
32 * @entry: entry alloc->buffers
33 * @rb_node: node for allocated_buffers/free_buffers rb trees
34 * @free: %true if buffer is free
35 * @allow_user_free: %true if user is allowed to free buffer
36 * @async_transaction: %true if buffer is in use for an async txn
37 * @debug_id: unique ID for debugging
38 * @transaction: pointer to associated struct binder_transaction
39 * @target_node: struct binder_node associated with this buffer
40 * @data_size: size of @transaction data
41 * @offsets_size: size of array of offsets
42 * @extra_buffers_size: size of space for other objects (like sg lists)
43 * @user_data: user pointer to base of buffer space
44 *
45 * Bookkeeping structure for binder transaction buffers
46 */
47struct binder_buffer {
48 struct list_head entry; /* free and allocated entries by address */
49 struct rb_node rb_node; /* free entry by size or allocated entry */
50 /* by address */
51 unsigned free:1;
52 unsigned allow_user_free:1;
53 unsigned async_transaction:1;
54 unsigned debug_id:29;
55
56 struct binder_transaction *transaction;
57
58 struct binder_node *target_node;
59 size_t data_size;
60 size_t offsets_size;
61 size_t extra_buffers_size;
62 void __user *user_data;
63};
64
65/**
66 * struct binder_lru_page - page object used for binder shrinker
67 * @page_ptr: pointer to physical page in mmap'd space
68 * @lru: entry in binder_alloc_lru
69 * @alloc: binder_alloc for a proc
70 */
71struct binder_lru_page {
72 struct list_head lru;
73 struct page *page_ptr;
74 struct binder_alloc *alloc;
75};
76
77/**
78 * struct binder_alloc - per-binder proc state for binder allocator
79 * @vma: vm_area_struct passed to mmap_handler
80 * (invarient after mmap)
81 * @tsk: tid for task that called init for this proc
82 * (invariant after init)
83 * @vma_vm_mm: copy of vma->vm_mm (invarient after mmap)
84 * @buffer: base of per-proc address space mapped via mmap
85 * @buffers: list of all buffers for this proc
86 * @free_buffers: rb tree of buffers available for allocation
87 * sorted by size
88 * @allocated_buffers: rb tree of allocated buffers sorted by address
89 * @free_async_space: VA space available for async buffers. This is
90 * initialized at mmap time to 1/2 the full VA space
91 * @pages: array of binder_lru_page
92 * @buffer_size: size of address space specified via mmap
93 * @pid: pid for associated binder_proc (invariant after init)
94 * @pages_high: high watermark of offset in @pages
95 *
96 * Bookkeeping structure for per-proc address space management for binder
97 * buffers. It is normally initialized during binder_init() and binder_mmap()
98 * calls. The address space is used for both user-visible buffers and for
99 * struct binder_buffer objects used to track the user buffers
100 */
101struct binder_alloc {
102 struct mutex mutex;
103 struct vm_area_struct *vma;
104 struct mm_struct *vma_vm_mm;
105 void __user *buffer;
106 struct list_head buffers;
107 struct rb_root free_buffers;
108 struct rb_root allocated_buffers;
109 size_t free_async_space;
110 struct binder_lru_page *pages;
111 size_t buffer_size;
112 uint32_t buffer_free;
113 int pid;
114 size_t pages_high;
115};
116
117#ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST
118void binder_selftest_alloc(struct binder_alloc *alloc);
119#else
120static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
121#endif
122enum lru_status binder_alloc_free_page(struct list_head *item,
123 struct list_lru_one *lru,
124 spinlock_t *lock, void *cb_arg);
125extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
126 size_t data_size,
127 size_t offsets_size,
128 size_t extra_buffers_size,
129 int is_async);
130extern void binder_alloc_init(struct binder_alloc *alloc);
131extern int binder_alloc_shrinker_init(void);
132extern void binder_alloc_vma_close(struct binder_alloc *alloc);
133extern struct binder_buffer *
134binder_alloc_prepare_to_free(struct binder_alloc *alloc,
135 uintptr_t user_ptr);
136extern void binder_alloc_free_buf(struct binder_alloc *alloc,
137 struct binder_buffer *buffer);
138extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
139 struct vm_area_struct *vma);
140extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
141extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
142extern void binder_alloc_print_allocated(struct seq_file *m,
143 struct binder_alloc *alloc);
144void binder_alloc_print_pages(struct seq_file *m,
145 struct binder_alloc *alloc);
146
147/**
148 * binder_alloc_get_free_async_space() - get free space available for async
149 * @alloc: binder_alloc for this proc
150 *
151 * Return: the bytes remaining in the address-space for async transactions
152 */
153static inline size_t
154binder_alloc_get_free_async_space(struct binder_alloc *alloc)
155{
156 size_t free_async_space;
157
158 mutex_lock(&alloc->mutex);
159 free_async_space = alloc->free_async_space;
160 mutex_unlock(&alloc->mutex);
161 return free_async_space;
162}
163
164unsigned long
165binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
166 struct binder_buffer *buffer,
167 binder_size_t buffer_offset,
168 const void __user *from,
169 size_t bytes);
170
171void binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
172 struct binder_buffer *buffer,
173 binder_size_t buffer_offset,
174 void *src,
175 size_t bytes);
176
177void binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
178 void *dest,
179 struct binder_buffer *buffer,
180 binder_size_t buffer_offset,
181 size_t bytes);
182
183#endif /* _LINUX_BINDER_ALLOC_H */
184
185