1// SPDX-License-Identifier: GPL-2.0
2#include <linux/init.h>
3#include <linux/module.h>
4#include <linux/sizes.h>
5#include <asm/page.h>
6#include <asm/addrspace.h>
7
8/*
9 * This is the offset of the uncached section from its cached alias.
10 *
11 * Legacy platforms handle trivial transitions between cached and
12 * uncached segments by making use of the 1:1 mapping relationship in
13 * 512MB lowmem, others via a special uncached mapping.
14 *
15 * Default value only valid in 29 bit mode, in 32bit mode this will be
16 * updated by the early PMB initialization code.
17 */
18unsigned long cached_to_uncached = SZ_512M;
19unsigned long uncached_size = SZ_512M;
20unsigned long uncached_start, uncached_end;
21EXPORT_SYMBOL(uncached_start);
22EXPORT_SYMBOL(uncached_end);
23
24int virt_addr_uncached(unsigned long kaddr)
25{
26	return (kaddr >= uncached_start) && (kaddr < uncached_end);
27}
28EXPORT_SYMBOL(virt_addr_uncached);
29
30void __init uncached_init(void)
31{
32#if defined(CONFIG_29BIT) || !defined(CONFIG_MMU)
33	uncached_start = P2SEG;
34#else
35	uncached_start = memory_end;
36#endif
37	uncached_end = uncached_start + uncached_size;
38}
39
40void __init uncached_resize(unsigned long size)
41{
42	uncached_size = size;
43	uncached_end = uncached_start + uncached_size;
44}
45