drivers/android/binder_alloc.h

   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
  27 extern struct list_lru binder_alloc_lru;
  28 struct 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  */
  47 struct 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  */
  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  * @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 __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
 118 void binder_selftest_alloc(struct binder_alloc *alloc);
 119 #else
 120 static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
 121 #endif
 122 enum lru_status binder_alloc_free_page(struct list_head *item,
 123                                        struct list_lru_one *lru,
 124                                        spinlock_t *lock, void *cb_arg);
 125 extern 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);
 130 extern void binder_alloc_init(struct binder_alloc *alloc);
 131 extern int binder_alloc_shrinker_init(void);
 132 extern void binder_alloc_vma_close(struct binder_alloc *alloc);
 133 extern struct binder_buffer *
 134 binder_alloc_prepare_to_free(struct binder_alloc *alloc,
 135                              uintptr_t user_ptr);
 136 extern void binder_alloc_free_buf(struct binder_alloc *alloc,
 137                                   struct binder_buffer *buffer);
 138 extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 139                                      struct vm_area_struct *vma);
 140 extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
 141 extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
 142 extern void binder_alloc_print_allocated(struct seq_file *m,
 143                                          struct binder_alloc *alloc);
 144 void 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  */
 153 static inline size_t
 154 binder_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
 164 unsigned long
 165 binder_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
 171 void 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
 177 void 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