[linux-2.6-block.git] / drivers / android / binder_alloc.h

/*
 * Copyright (C) 2017 Google, Inc.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#ifndef _LINUX_BINDER_ALLOC_H
#define _LINUX_BINDER_ALLOC_H

#include <linux/rbtree.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/rtmutex.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>

struct binder_transaction;

/**
 * struct binder_buffer - buffer used for binder transactions
 * @entry:              entry alloc->buffers
 * @rb_node:            node for allocated_buffers/free_buffers rb trees
 * @free:               true if buffer is free
 * @allow_user_free:    describe the second member of struct blah,
 * @async_transaction:  describe the second member of struct blah,
 * @debug_id:           describe the second member of struct blah,
 * @transaction:        describe the second member of struct blah,
 * @target_node:        describe the second member of struct blah,
 * @data_size:          describe the second member of struct blah,
 * @offsets_size:       describe the second member of struct blah,
 * @extra_buffers_size: describe the second member of struct blah,
 * @data:i              describe the second member of struct blah,
 *
 * Bookkeeping structure for binder transaction buffers
 */
struct binder_buffer {
	struct list_head entry; /* free and allocated entries by address */
	struct rb_node rb_node; /* free entry by size or allocated entry */
				/* by address */
	unsigned free:1;
	unsigned allow_user_free:1;
	unsigned async_transaction:1;
	unsigned free_in_progress:1;
	unsigned debug_id:28;

	struct binder_transaction *transaction;

	struct binder_node *target_node;
	size_t data_size;
	size_t offsets_size;
	size_t extra_buffers_size;
	uint8_t data[0];
};

/**
 * struct binder_alloc - per-binder proc state for binder allocator
 * @vma:                vm_area_struct passed to mmap_handler
 *                      (invarient after mmap)
 * @tsk:                tid for task that called init for this proc
 *                      (invariant after init)
 * @vma_vm_mm:          copy of vma->vm_mm (invarient after mmap)
 * @buffer:             base of per-proc address space mapped via mmap
 * @user_buffer_offset: offset between user and kernel VAs for buffer
 * @buffers:            list of all buffers for this proc
 * @free_buffers:       rb tree of buffers available for allocation
 *                      sorted by size
 * @allocated_buffers:  rb tree of allocated buffers sorted by address
 * @free_async_space:   VA space available for async buffers. This is
 *                      initialized at mmap time to 1/2 the full VA space
 * @pages:              array of physical page addresses for each
 *                      page of mmap'd space
 * @buffer_size:        size of address space specified via mmap
 * @pid:                pid for associated binder_proc (invariant after init)
 *
 * Bookkeeping structure for per-proc address space management for binder
 * buffers. It is normally initialized during binder_init() and binder_mmap()
 * calls. The address space is used for both user-visible buffers and for
 * struct binder_buffer objects used to track the user buffers
 */
struct binder_alloc {
	struct mutex mutex;
	struct task_struct *tsk;
	struct vm_area_struct *vma;
	struct mm_struct *vma_vm_mm;
	void *buffer;
	ptrdiff_t user_buffer_offset;
	struct list_head buffers;
	struct rb_root free_buffers;
	struct rb_root allocated_buffers;
	size_t free_async_space;
	struct page **pages;
	size_t buffer_size;
	uint32_t buffer_free;
	int pid;
};

extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
						  size_t data_size,
						  size_t offsets_size,
						  size_t extra_buffers_size,
						  int is_async);
extern void binder_alloc_init(struct binder_alloc *alloc);
extern void binder_alloc_vma_close(struct binder_alloc *alloc);
extern struct binder_buffer *
binder_alloc_prepare_to_free(struct binder_alloc *alloc,
			     uintptr_t user_ptr);
extern void binder_alloc_free_buf(struct binder_alloc *alloc,
				  struct binder_buffer *buffer);
extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
				     struct vm_area_struct *vma);
extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
extern void binder_alloc_print_allocated(struct seq_file *m,
					 struct binder_alloc *alloc);

/**
 * binder_alloc_get_free_async_space() - get free space available for async
 * @alloc:	binder_alloc for this proc
 *
 * Return:	the bytes remaining in the address-space for async transactions
 */
static inline size_t
binder_alloc_get_free_async_space(struct binder_alloc *alloc)
{
	size_t free_async_space;

	mutex_lock(&alloc->mutex);
	free_async_space = alloc->free_async_space;
	mutex_unlock(&alloc->mutex);
	return free_async_space;
}

/**
 * binder_alloc_get_user_buffer_offset() - get offset between kernel/user addrs
 * @alloc:	binder_alloc for this proc
 *
 * Return:	the offset between kernel and user-space addresses to use for
 * virtual address conversion
 */
static inline ptrdiff_t
binder_alloc_get_user_buffer_offset(struct binder_alloc *alloc)
{
	/*
	 * user_buffer_offset is constant if vma is set and
	 * undefined if vma is not set. It is possible to
	 * get here with !alloc->vma if the target process
	 * is dying while a transaction is being initiated.
	 * Returning the old value is ok in this case and
	 * the transaction will fail.
	 */
	return alloc->user_buffer_offset;
}

#endif /* _LINUX_BINDER_ALLOC_H */
Commit	Line	Data
0c972a05 TK	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
	25	struct binder_transaction;
	26
	27	/**
	28	* struct binder_buffer - buffer used for binder transactions
	29	* @entry: entry alloc->buffers
	30	* @rb_node: node for allocated_buffers/free_buffers rb trees
	31	* @free: true if buffer is free
	32	* @allow_user_free: describe the second member of struct blah,
	33	* @async_transaction: describe the second member of struct blah,
	34	* @debug_id: describe the second member of struct blah,
	35	* @transaction: describe the second member of struct blah,
	36	* @target_node: describe the second member of struct blah,
	37	* @data_size: describe the second member of struct blah,
	38	* @offsets_size: describe the second member of struct blah,
	39	* @extra_buffers_size: describe the second member of struct blah,
	40	* @data:i describe the second member of struct blah,
	41	*
	42	* Bookkeeping structure for binder transaction buffers
	43	*/
	44	struct binder_buffer {
	45	struct list_head entry; /* free and allocated entries by address */
	46	struct rb_node rb_node; /* free entry by size or allocated entry */
	47	/* by address */
	48	unsigned free:1;
	49	unsigned allow_user_free:1;
	50	unsigned async_transaction:1;
53d311cf TK	51	unsigned free_in_progress:1;
53d311cf TK	52	unsigned debug_id:28;
0c972a05 TK	53
	54	struct binder_transaction *transaction;
	55
	56	struct binder_node *target_node;
	57	size_t data_size;
	58	size_t offsets_size;
	59	size_t extra_buffers_size;
	60	uint8_t data[0];
	61	};
	62
	63	/**
	64	* struct binder_alloc - per-binder proc state for binder allocator
	65	* @vma: vm_area_struct passed to mmap_handler
	66	* (invarient after mmap)
	67	* @tsk: tid for task that called init for this proc
	68	* (invariant after init)
	69	* @vma_vm_mm: copy of vma->vm_mm (invarient after mmap)
	70	* @buffer: base of per-proc address space mapped via mmap
	71	* @user_buffer_offset: offset between user and kernel VAs for buffer
	72	* @buffers: list of all buffers for this proc
	73	* @free_buffers: rb tree of buffers available for allocation
	74	* sorted by size
	75	* @allocated_buffers: rb tree of allocated buffers sorted by address
	76	* @free_async_space: VA space available for async buffers. This is
	77	* initialized at mmap time to 1/2 the full VA space
	78	* @pages: array of physical page addresses for each
	79	* page of mmap'd space
	80	* @buffer_size: size of address space specified via mmap
	81	* @pid: pid for associated binder_proc (invariant after init)
	82	*
	83	* Bookkeeping structure for per-proc address space management for binder
	84	* buffers. It is normally initialized during binder_init() and binder_mmap()
	85	* calls. The address space is used for both user-visible buffers and for
	86	* struct binder_buffer objects used to track the user buffers
	87	*/
	88	struct binder_alloc {
	89	struct mutex mutex;
	90	struct task_struct *tsk;
	91	struct vm_area_struct *vma;
	92	struct mm_struct *vma_vm_mm;
	93	void *buffer;
	94	ptrdiff_t user_buffer_offset;
	95	struct list_head buffers;
	96	struct rb_root free_buffers;
	97	struct rb_root allocated_buffers;
	98	size_t free_async_space;
	99	struct page **pages;
	100	size_t buffer_size;
	101	uint32_t buffer_free;
	102	int pid;
	103	};
	104
	105	extern struct binder_buffer binder_alloc_new_buf(struct binder_alloc alloc,
	106	size_t data_size,
	107	size_t offsets_size,
	108	size_t extra_buffers_size,
	109	int is_async);
	110	extern void binder_alloc_init(struct binder_alloc *alloc);
	111	extern void binder_alloc_vma_close(struct binder_alloc *alloc);
	112	extern struct binder_buffer *
53d311cf TK	113	binder_alloc_prepare_to_free(struct binder_alloc *alloc,
53d311cf TK	114	uintptr_t user_ptr);
0c972a05 TK	115	extern void binder_alloc_free_buf(struct binder_alloc *alloc,
	116	struct binder_buffer *buffer);
	117	extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
	118	struct vm_area_struct *vma);
	119	extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
	120	extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
	121	extern void binder_alloc_print_allocated(struct seq_file *m,
	122	struct binder_alloc *alloc);
	123
	124	/**
	125	* binder_alloc_get_free_async_space() - get free space available for async
	126	* @alloc: binder_alloc for this proc
	127	*
	128	* Return: the bytes remaining in the address-space for async transactions
	129	*/
	130	static inline size_t
	131	binder_alloc_get_free_async_space(struct binder_alloc *alloc)
	132	{
	133	size_t free_async_space;
	134
	135	mutex_lock(&alloc->mutex);
	136	free_async_space = alloc->free_async_space;
	137	mutex_unlock(&alloc->mutex);
	138	return free_async_space;
	139	}
	140
	141	/**
	142	* binder_alloc_get_user_buffer_offset() - get offset between kernel/user addrs
	143	* @alloc: binder_alloc for this proc
	144	*
	145	* Return: the offset between kernel and user-space addresses to use for
	146	* virtual address conversion
	147	*/
	148	static inline ptrdiff_t
	149	binder_alloc_get_user_buffer_offset(struct binder_alloc *alloc)
	150	{
	151	/*
	152	* user_buffer_offset is constant if vma is set and
	153	* undefined if vma is not set. It is possible to
	154	* get here with !alloc->vma if the target process
	155	* is dying while a transaction is being initiated.
	156	* Returning the old value is ok in this case and
	157	* the transaction will fail.
	158	*/
	159	return alloc->user_buffer_offset;
	160	}
	161
	162	#endif /* _LINUX_BINDER_ALLOC_H */
	163