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Diffstat (limited to 'drivers/android/binder_alloc.h')
| -rw-r--r-- | drivers/android/binder_alloc.h | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h new file mode 100644 index 000000000000..721c511431f9 --- /dev/null +++ b/drivers/android/binder_alloc.h @@ -0,0 +1,162 @@ +/* + * 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 debug_id:29; + + 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_buffer_lookup(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 */ + |