LXR linux/drivers/android/binder

   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 * @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 */
  38struct 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 */
  62struct 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 */
  92struct 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
 109void binder_selftest_alloc(struct binder_alloc *alloc);
 110#else
 111static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
 112#endif
 113enum lru_status binder_alloc_free_page(struct list_head *item,
 114                                       struct list_lru_one *lru,
 115                                       spinlock_t *lock, void *cb_arg);
 116extern 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);
 121extern void binder_alloc_init(struct binder_alloc *alloc);
 122extern int binder_alloc_shrinker_init(void);
 123extern void binder_alloc_vma_close(struct binder_alloc *alloc);
 124extern struct binder_buffer *
 125binder_alloc_prepare_to_free(struct binder_alloc *alloc,
 126                             uintptr_t user_ptr);
 127extern void binder_alloc_free_buf(struct binder_alloc *alloc,
 128                                  struct binder_buffer *buffer);
 129extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 130                                     struct vm_area_struct *vma);
 131extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
 132extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
 133extern void binder_alloc_print_allocated(struct seq_file *m,
 134                                         struct binder_alloc *alloc);
 135void 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 */
 144static inline size_t
 145binder_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
 155unsigned long
 156binder_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
 162int 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
 168int 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