linux_dsm_epyc7002/lib/xarray.c
Matthew Wilcox f8d5d0cc14 xarray: Add definition of struct xarray
This is a direct replacement for struct radix_tree_root.  Some of the
struct members have changed name; convert those, and use a #define so
that radix_tree users continue to work without change.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
2018-10-21 10:45:53 -04:00

45 lines
1.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* XArray implementation
* Copyright (c) 2017 Microsoft Corporation
* Author: Matthew Wilcox <willy@infradead.org>
*/
#include <linux/export.h>
#include <linux/xarray.h>
/*
* Coding conventions in this file:
*
* @xa is used to refer to the entire xarray.
* @xas is the 'xarray operation state'. It may be either a pointer to
* an xa_state, or an xa_state stored on the stack. This is an unfortunate
* ambiguity.
* @index is the index of the entry being operated on
* @mark is an xa_mark_t; a small number indicating one of the mark bits.
* @node refers to an xa_node; usually the primary one being operated on by
* this function.
* @offset is the index into the slots array inside an xa_node.
* @parent refers to the @xa_node closer to the head than @node.
* @entry refers to something stored in a slot in the xarray
*/
/**
* xa_init_flags() - Initialise an empty XArray with flags.
* @xa: XArray.
* @flags: XA_FLAG values.
*
* If you need to initialise an XArray with special flags (eg you need
* to take the lock from interrupt context), use this function instead
* of xa_init().
*
* Context: Any context.
*/
void xa_init_flags(struct xarray *xa, gfp_t flags)
{
spin_lock_init(&xa->xa_lock);
xa->xa_flags = flags;
xa->xa_head = NULL;
}
EXPORT_SYMBOL(xa_init_flags);