1/* SPDX-License-Identifier: GPL-2.0 */
2// Copyright (C) 2005-2017 Andes Technology Corporation
3
4#ifndef _ASM_HIGHMEM_H
5#define _ASM_HIGHMEM_H
6
7#include <asm/proc-fns.h>
8#include <asm/kmap_types.h>
9#include <asm/fixmap.h>
10
11/*
12 * Right now we initialize only a single pte table. It can be extended
13 * easily, subsequent pte tables have to be allocated in one physical
14 * chunk of RAM.
15 */
16/*
17 * Ordering is (from lower to higher memory addresses):
18 *
19 * high_memory
20 *			Persistent kmap area
21 * PKMAP_BASE
22 *			fixed_addresses
23 * FIXADDR_START
24 * FIXADDR_TOP
25 *			Vmalloc area
26 * VMALLOC_START
27 * VMALLOC_END
28 */
29#define PKMAP_BASE		((FIXADDR_START - PGDIR_SIZE) & (PGDIR_MASK))
30#define LAST_PKMAP		PTRS_PER_PTE
31#define LAST_PKMAP_MASK		(LAST_PKMAP - 1)
32#define PKMAP_NR(virt)		(((virt) - (PKMAP_BASE)) >> PAGE_SHIFT)
33#define PKMAP_ADDR(nr)		(PKMAP_BASE + ((nr) << PAGE_SHIFT))
34
35static inline void flush_cache_kmaps(void)
36{
37	cpu_dcache_wbinval_all();
38}
39
40/* declarations for highmem.c */
41extern unsigned long highstart_pfn, highend_pfn;
42
43extern pte_t *pkmap_page_table;
44
45extern void kmap_init(void);
46
47/*
48 * The following functions are already defined by <linux/highmem.h>
49 * when CONFIG_HIGHMEM is not set.
50 */
51#ifdef CONFIG_HIGHMEM
52extern void *kmap_atomic_pfn(unsigned long pfn);
53#endif
54
55#endif
56