/* SPDX-License-Identifier: GPL-2.0-only */

  /*
   * Copyright (C) 2017 Google, Inc.

   */
  
  #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>

  #include <linux/list_lru.h>

  #include <uapi/linux/android/binder.h>

  extern struct list_lru binder_alloc_lru;

  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

   * @clear_on_free:      %true if buffer must be zeroed after use

   * @allow_user_free:    %true if user is allowed to free buffer
   * @async_transaction:  %true if buffer is in use for an async txn
   * @debug_id:           unique ID for debugging
   * @transaction:        pointer to associated struct binder_transaction
   * @target_node:        struct binder_node associated with this buffer
   * @data_size:          size of @transaction data
   * @offsets_size:       size of array of offsets
   * @extra_buffers_size: size of space for other objects (like sg lists)

   * @user_data:          user pointer to base of buffer space

   * @pid:                pid to attribute the buffer to (caller)

   *
   * 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 clear_on_free:1;

  	unsigned allow_user_free:1;
  	unsigned async_transaction: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;

  	void __user *user_data;

  	int    pid;

  };
  
  /**

   * struct binder_lru_page - page object used for binder shrinker
   * @page_ptr: pointer to physical page in mmap'd space
   * @lru:      entry in binder_alloc_lru
   * @alloc:    binder_alloc for a proc
   */
  struct binder_lru_page {
  	struct list_head lru;
  	struct page *page_ptr;
  	struct binder_alloc *alloc;
  };
  
  /**

   * 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

   * @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 binder_lru_page

   * @buffer_size:        size of address space specified via mmap
   * @pid:                pid for associated binder_proc (invariant after init)

   * @pages_high:         high watermark of offset in @pages

   *
   * 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 vm_area_struct *vma;
  	struct mm_struct *vma_vm_mm;

  	void __user *buffer;

  	struct list_head buffers;
  	struct rb_root free_buffers;
  	struct rb_root allocated_buffers;
  	size_t free_async_space;

  	struct binder_lru_page *pages;

  	size_t buffer_size;
  	uint32_t buffer_free;
  	int pid;

  	size_t pages_high;

  };

  #ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST
  void binder_selftest_alloc(struct binder_alloc *alloc);
  #else
  static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
  #endif

  enum lru_status binder_alloc_free_page(struct list_head *item,
  				       struct list_lru_one *lru,
  				       spinlock_t *lock, void *cb_arg);

  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,
  						  int pid);

  extern void binder_alloc_init(struct binder_alloc *alloc);

  extern int binder_alloc_shrinker_init(void);

  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);

  void binder_alloc_print_pages(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;
  }

  unsigned long
  binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
  				 struct binder_buffer *buffer,
  				 binder_size_t buffer_offset,
  				 const void __user *from,
  				 size_t bytes);

  int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
  				struct binder_buffer *buffer,
  				binder_size_t buffer_offset,
  				void *src,
  				size_t bytes);
  
  int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
  				  void *dest,
  				  struct binder_buffer *buffer,
  				  binder_size_t buffer_offset,
  				  size_t bytes);

  #endif /* _LINUX_BINDER_ALLOC_H */