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: describe the second member of struct blah, 35 * @async_transaction: describe the second member of struct blah, 36 * @debug_id: describe the second member of struct blah, 37 * @transaction: describe the second member of struct blah, 38 * @target_node: describe the second member of struct blah, 39 * @data_size: describe the second member of struct blah, 40 * @offsets_size: describe the second member of struct blah, 41 * @extra_buffers_size: describe the second member of struct blah, 42 * @data:i describe the second member of struct blah, 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 free_in_progress:1; 54 unsigned debug_id:28; 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 *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 */ 71 struct 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 * @user_buffer_offset: offset between user and kernel VAs for buffer 86 * @buffers: list of all buffers for this proc 87 * @free_buffers: rb tree of buffers available for allocation 88 * sorted by size 89 * @allocated_buffers: rb tree of allocated buffers sorted by address 90 * @free_async_space: VA space available for async buffers. This is 91 * initialized at mmap time to 1/2 the full VA space 92 * @pages: array of binder_lru_page 93 * @buffer_size: size of address space specified via mmap 94 * @pid: pid for associated binder_proc (invariant after init) 95 * @pages_high: high watermark of offset in @pages 96 * 97 * Bookkeeping structure for per-proc address space management for binder 98 * buffers. It is normally initialized during binder_init() and binder_mmap() 99 * calls. The address space is used for both user-visible buffers and for 100 * struct binder_buffer objects used to track the user buffers 101 */ 102 struct binder_alloc { 103 struct mutex mutex; 104 struct vm_area_struct *vma; 105 struct mm_struct *vma_vm_mm; 106 void *buffer; 107 ptrdiff_t user_buffer_offset; 108 struct list_head buffers; 109 struct rb_root free_buffers; 110 struct rb_root allocated_buffers; 111 size_t free_async_space; 112 struct binder_lru_page *pages; 113 size_t buffer_size; 114 uint32_t buffer_free; 115 int pid; 116 size_t pages_high; 117 }; 118 119 #ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST 120 void binder_selftest_alloc(struct binder_alloc *alloc); 121 #else 122 static inline void binder_selftest_alloc(struct binder_alloc *alloc) {} 123 #endif 124 enum lru_status binder_alloc_free_page(struct list_head *item, 125 struct list_lru_one *lru, 126 spinlock_t *lock, void *cb_arg); 127 extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc, 128 size_t data_size, 129 size_t offsets_size, 130 size_t extra_buffers_size, 131 int is_async); 132 extern void binder_alloc_init(struct binder_alloc *alloc); 133 extern int binder_alloc_shrinker_init(void); 134 extern void binder_alloc_vma_close(struct binder_alloc *alloc); 135 extern struct binder_buffer * 136 binder_alloc_prepare_to_free(struct binder_alloc *alloc, 137 uintptr_t user_ptr); 138 extern void binder_alloc_free_buf(struct binder_alloc *alloc, 139 struct binder_buffer *buffer); 140 extern int binder_alloc_mmap_handler(struct binder_alloc *alloc, 141 struct vm_area_struct *vma); 142 extern void binder_alloc_deferred_release(struct binder_alloc *alloc); 143 extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc); 144 extern void binder_alloc_print_allocated(struct seq_file *m, 145 struct binder_alloc *alloc); 146 void binder_alloc_print_pages(struct seq_file *m, 147 struct binder_alloc *alloc); 148 149 /** 150 * binder_alloc_get_free_async_space() - get free space available for async 151 * @alloc: binder_alloc for this proc 152 * 153 * Return: the bytes remaining in the address-space for async transactions 154 */ 155 static inline size_t 156 binder_alloc_get_free_async_space(struct binder_alloc *alloc) 157 { 158 size_t free_async_space; 159 160 mutex_lock(&alloc->mutex); 161 free_async_space = alloc->free_async_space; 162 mutex_unlock(&alloc->mutex); 163 return free_async_space; 164 } 165 166 /** 167 * binder_alloc_get_user_buffer_offset() - get offset between kernel/user addrs 168 * @alloc: binder_alloc for this proc 169 * 170 * Return: the offset between kernel and user-space addresses to use for 171 * virtual address conversion 172 */ 173 static inline ptrdiff_t 174 binder_alloc_get_user_buffer_offset(struct binder_alloc *alloc) 175 { 176 /* 177 * user_buffer_offset is constant if vma is set and 178 * undefined if vma is not set. It is possible to 179 * get here with !alloc->vma if the target process 180 * is dying while a transaction is being initiated. 181 * Returning the old value is ok in this case and 182 * the transaction will fail. 183 */ 184 return alloc->user_buffer_offset; 185 } 186 187 #endif /* _LINUX_BINDER_ALLOC_H */ 188 189