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
18extern struct list_lru binder_alloc_lru;
19struct 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 * @clear_on_free:      %true if buffer must be zeroed after use
27 * @allow_user_free:    %true if user is allowed to free buffer
28 * @async_transaction:  %true if buffer is in use for an async txn
29 * @debug_id:           unique ID for debugging
30 * @transaction:        pointer to associated struct binder_transaction
31 * @target_node:        struct binder_node associated with this buffer
32 * @data_size:          size of @transaction data
33 * @offsets_size:       size of array of offsets
34 * @extra_buffers_size: size of space for other objects (like sg lists)
35 * @user_data:          user pointer to base of buffer space
36 * @pid:                pid to attribute the buffer to (caller)
37 *
38 * Bookkeeping structure for binder transaction buffers
39 */
40struct binder_buffer {
41	struct list_head entry; /* free and allocated entries by address */
42	struct rb_node rb_node; /* free entry by size or allocated entry */
43				/* by address */
44	unsigned free:1;
45	unsigned clear_on_free:1;
46	unsigned allow_user_free:1;
47	unsigned async_transaction:1;
48	unsigned debug_id:28;
49
50	struct binder_transaction *transaction;
51
52	struct binder_node *target_node;
53	size_t data_size;
54	size_t offsets_size;
55	size_t extra_buffers_size;
56	void __user *user_data;
57	int    pid;
58};
59
60/**
61 * struct binder_lru_page - page object used for binder shrinker
62 * @page_ptr: pointer to physical page in mmap'd space
63 * @lru:      entry in binder_alloc_lru
64 * @alloc:    binder_alloc for a proc
65 */
66struct binder_lru_page {
67	struct list_head lru;
68	struct page *page_ptr;
69	struct binder_alloc *alloc;
70};
71
72/**
73 * struct binder_alloc - per-binder proc state for binder allocator
74 * @vma:                vm_area_struct passed to mmap_handler
75 *                      (invarient after mmap)
76 * @tsk:                tid for task that called init for this proc
77 *                      (invariant after init)
78 * @vma_vm_mm:          copy of vma->vm_mm (invarient after mmap)
79 * @buffer:             base of per-proc address space mapped via mmap
80 * @buffers:            list of all buffers for this proc
81 * @free_buffers:       rb tree of buffers available for allocation
82 *                      sorted by size
83 * @allocated_buffers:  rb tree of allocated buffers sorted by address
84 * @free_async_space:   VA space available for async buffers. This is
85 *                      initialized at mmap time to 1/2 the full VA space
86 * @pages:              array of binder_lru_page
87 * @buffer_size:        size of address space specified via mmap
88 * @pid:                pid for associated binder_proc (invariant after init)
89 * @pages_high:         high watermark of offset in @pages
90 *
91 * Bookkeeping structure for per-proc address space management for binder
92 * buffers. It is normally initialized during binder_init() and binder_mmap()
93 * calls. The address space is used for both user-visible buffers and for
94 * struct binder_buffer objects used to track the user buffers
95 */
96struct binder_alloc {
97	struct mutex mutex;
98	struct vm_area_struct *vma;
99	struct mm_struct *vma_vm_mm;
100	void __user *buffer;
101	struct list_head buffers;
102	struct rb_root free_buffers;
103	struct rb_root allocated_buffers;
104	size_t free_async_space;
105	struct binder_lru_page *pages;
106	size_t buffer_size;
107	uint32_t buffer_free;
108	int pid;
109	size_t pages_high;
110};
111
112#ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST
113void binder_selftest_alloc(struct binder_alloc *alloc);
114#else
115static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
116#endif
117enum lru_status binder_alloc_free_page(struct list_head *item,
118				       struct list_lru_one *lru,
119				       spinlock_t *lock, void *cb_arg);
120extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
121						  size_t data_size,
122						  size_t offsets_size,
123						  size_t extra_buffers_size,
124						  int is_async,
125						  int pid);
126extern void binder_alloc_init(struct binder_alloc *alloc);
127extern int binder_alloc_shrinker_init(void);
128extern void binder_alloc_shrinker_exit(void);
129extern void binder_alloc_vma_close(struct binder_alloc *alloc);
130extern struct binder_buffer *
131binder_alloc_prepare_to_free(struct binder_alloc *alloc,
132			     uintptr_t user_ptr);
133extern void binder_alloc_free_buf(struct binder_alloc *alloc,
134				  struct binder_buffer *buffer);
135extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
136				     struct vm_area_struct *vma);
137extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
138extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
139extern void binder_alloc_print_allocated(struct seq_file *m,
140					 struct binder_alloc *alloc);
141void binder_alloc_print_pages(struct seq_file *m,
142			      struct binder_alloc *alloc);
143
144/**
145 * binder_alloc_get_free_async_space() - get free space available for async
146 * @alloc:	binder_alloc for this proc
147 *
148 * Return:	the bytes remaining in the address-space for async transactions
149 */
150static inline size_t
151binder_alloc_get_free_async_space(struct binder_alloc *alloc)
152{
153	size_t free_async_space;
154
155	mutex_lock(&alloc->mutex);
156	free_async_space = alloc->free_async_space;
157	mutex_unlock(&alloc->mutex);
158	return free_async_space;
159}
160
161unsigned long
162binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
163				 struct binder_buffer *buffer,
164				 binder_size_t buffer_offset,
165				 const void __user *from,
166				 size_t bytes);
167
168int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
169				struct binder_buffer *buffer,
170				binder_size_t buffer_offset,
171				void *src,
172				size_t bytes);
173
174int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
175				  void *dest,
176				  struct binder_buffer *buffer,
177				  binder_size_t buffer_offset,
178				  size_t bytes);
179
180#endif /* _LINUX_BINDER_ALLOC_H */
181
182