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-rw-r--r--drivers/android/binder_alloc.h162
1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h
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+/*
+ * 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 */
+

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