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 
176