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 26 extern struct list_lru binder_alloc_lru; 27 struct binder_transaction; 28 29 /** 30 * struct binder_buffer - buffer used for binder transactions 31 * @entry: entry alloc->buffers 32 * @rb_node: node for allocated_buffers/free_buffers rb trees 33 * @free: %true if buffer is free 34 * @allow_user_free: %true if user is allowed to free buffer 35 * @async_transaction: %true if buffer is in use for an async txn 36 * @debug_id: unique ID for debugging 37 * @transaction: pointer to associated struct binder_transaction 38 * @target_node: struct binder_node associated with this buffer 39 * @data_size: size of @transaction data 40 * @offsets_size: size of array of offsets 41 * @extra_buffers_size: size of space for other objects (like sg lists) 42 * @data: pointer to base of buffer space 43 * 44 * Bookkeeping structure for binder transaction buffers 45 */ 46 struct binder_buffer { 47 struct list_head entry; /* free and allocated entries by address */ 48 struct rb_node rb_node; /* free entry by size or allocated entry */ 49 /* by address */ 50 unsigned free:1; 51 unsigned allow_user_free:1; 52 unsigned async_transaction:1; 53 unsigned debug_id:29; 54 55 struct binder_transaction *transaction; 56 57 struct binder_node *target_node; 58 size_t data_size; 59 size_t offsets_size; 60 size_t extra_buffers_size; 61 void *data; 62 }; 63 64 /** 65 * struct binder_lru_page - page object used for binder shrinker 66 * @page_ptr: pointer to physical page in mmap'd space 67 * @lru: entry in binder_alloc_lru 68 * @alloc: binder_alloc for a proc 69 */ 70 struct binder_lru_page { 71 struct list_head lru; 72 struct page *page_ptr; 73 struct binder_alloc *alloc; 74 }; 75 76 /** 77 * struct binder_alloc - per-binder proc state for binder allocator 78 * @vma: vm_area_struct passed to mmap_handler 79 * (invarient after mmap) 80 * @tsk: tid for task that called init for this proc 81 * (invariant after init) 82 * @vma_vm_mm: copy of vma->vm_mm (invarient after mmap) 83 * @buffer: base of per-proc address space mapped via mmap 84 * @user_buffer_offset: offset between user and kernel VAs for buffer 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 */ 101 struct binder_alloc { 102 struct mutex mutex; 103 struct vm_area_struct *vma; 104 struct mm_struct *vma_vm_mm; 105 void *buffer; 106 ptrdiff_t user_buffer_offset; 107 struct list_head buffers; 108 struct rb_root free_buffers; 109 struct rb_root allocated_buffers; 110 size_t free_async_space; 111 struct binder_lru_page *pages; 112 size_t buffer_size; 113 uint32_t buffer_free; 114 int pid; 115 size_t pages_high; 116 }; 117 118 #ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST 119 void binder_selftest_alloc(struct binder_alloc *alloc); 120 #else 121 static inline void binder_selftest_alloc(struct binder_alloc *alloc) {} 122 #endif 123 enum lru_status binder_alloc_free_page(struct list_head *item, 124 struct list_lru_one *lru, 125 spinlock_t *lock, void *cb_arg); 126 extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc, 127 size_t data_size, 128 size_t offsets_size, 129 size_t extra_buffers_size, 130 int is_async); 131 extern void binder_alloc_init(struct binder_alloc *alloc); 132 extern int binder_alloc_shrinker_init(void); 133 extern void binder_alloc_vma_close(struct binder_alloc *alloc); 134 extern struct binder_buffer * 135 binder_alloc_prepare_to_free(struct binder_alloc *alloc, 136 uintptr_t user_ptr); 137 extern void binder_alloc_free_buf(struct binder_alloc *alloc, 138 struct binder_buffer *buffer); 139 extern int binder_alloc_mmap_handler(struct binder_alloc *alloc, 140 struct vm_area_struct *vma); 141 extern void binder_alloc_deferred_release(struct binder_alloc *alloc); 142 extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc); 143 extern void binder_alloc_print_allocated(struct seq_file *m, 144 struct binder_alloc *alloc); 145 void binder_alloc_print_pages(struct seq_file *m, 146 struct binder_alloc *alloc); 147 148 /** 149 * binder_alloc_get_free_async_space() - get free space available for async 150 * @alloc: binder_alloc for this proc 151 * 152 * Return: the bytes remaining in the address-space for async transactions 153 */ 154 static inline size_t 155 binder_alloc_get_free_async_space(struct binder_alloc *alloc) 156 { 157 size_t free_async_space; 158 159 mutex_lock(&alloc->mutex); 160 free_async_space = alloc->free_async_space; 161 mutex_unlock(&alloc->mutex); 162 return free_async_space; 163 } 164 165 /** 166 * binder_alloc_get_user_buffer_offset() - get offset between kernel/user addrs 167 * @alloc: binder_alloc for this proc 168 * 169 * Return: the offset between kernel and user-space addresses to use for 170 * virtual address conversion 171 */ 172 static inline ptrdiff_t 173 binder_alloc_get_user_buffer_offset(struct binder_alloc *alloc) 174 { 175 /* 176 * user_buffer_offset is constant if vma is set and 177 * undefined if vma is not set. It is possible to 178 * get here with !alloc->vma if the target process 179 * is dying while a transaction is being initiated. 180 * Returning the old value is ok in this case and 181 * the transaction will fail. 182 */ 183 return alloc->user_buffer_offset; 184 } 185 186 #endif /* _LINUX_BINDER_ALLOC_H */ 187 188