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/*
* Copyright (C) 2013 Kay Sievers
* Copyright (C) 2013 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Copyright (C) 2013 Linux Foundation
* Copyright (C) 2013 Daniel Mack <daniel@zonque.org>
*
* kdbus is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the
* Free Software Foundation; either version 2.1 of the License, or (at
* your option) any later version.
*/
#ifndef __KDBUS_POOL_H
#define __KDBUS_POOL_H
/*
* Messages sent with KDBUS_CMD_MSG_SEND are copied direcly by the
* sending process into the receiver's pool. The receiver has provided
* the memory and registered it with KDBUS_HELLO_POOL.
*
* Messages received with KDBUS_CMD_MSG_RECV just return a pointer
* into the pool.
*
* The internally allocated memory needs to be returned by the receiver
* with * KDBUS_CMD_MSG_RELEASE.
*/
/* The receiver-provided buffer managed as a pool of allocated and free
* slices containing the queued messages. */
struct kdbus_pool {
void __user *buf; /* receiver-supplied buffer */
size_t size; /* size of buffer */
size_t busy; /* allocated size */
struct list_head slices; /* all slices sorted by address */
struct rb_root slices_busy; /* tree of allocated slices */
struct rb_root slices_free; /* tree of free slices */
};
/* The pool has one or more slices, always spanning the entire size of the
* pool.
*
* Every slice is an element in a list sorted by the buffer address, to
* provide access to the next neighbor slice.
*
* Every slice is member in either the busy or the free tree. The free
* tree is organized by slice size, the busy tree organized by buffer
* address. */
struct kdbus_slice {
void __user *buf; /* address of slice */
size_t size; /* size of slice */
struct list_head entry;
struct rb_node rb_node;
bool free;
struct page **pg; /* pages mapped by the slice */
unsigned int pg_n; /* number of pages */
size_t pg_off; /* offset into the first page */
void *pg_buf; /* kernel address of mapped pages */
};
int kdbus_pool_init(struct kdbus_pool *pool, void __user *buf, size_t size);
void kdbus_pool_cleanup(struct kdbus_pool *pool);
bool kdbus_pool_is_anon_map(struct mm_struct *mm,
void __user *buf, size_t size);
void __user *kdbus_pool_alloc(struct kdbus_pool *pool, size_t size,
struct kdbus_slice **slice);
int kdbus_pool_free(struct kdbus_pool *pool, void __user *buf);
int kdbus_pool_slice_map(struct kdbus_slice *slice, struct task_struct *task);
void kdbus_pool_slice_unmap(struct kdbus_slice *slice);
int kdbus_pool_slice_copy(struct kdbus_slice *slice, size_t off,
void *buf, size_t size);
int kdbus_pool_slice_copy_user(struct kdbus_slice *slice, size_t off,
void __user *buf, size_t size);
#endif
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