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