summaryrefslogtreecommitdiff
path: root/arch/mips/include/asm/highmem.h
blob: 24e7e7e5cc7b817a21d9a12f4bc5d1f58d7eca25 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * highmem.h: virtual kernel memory mappings for high memory
 *
 * Used in CONFIG_HIGHMEM systems for memory pages which
 * are not addressable by direct kernel virtual addresses.
 *
 * Copyright (C) 1999 Gerhard Wichert, Siemens AG
 *		      Gerhard.Wichert@pdb.siemens.de
 *
 *
 * Redesigned the x86 32-bit VM architecture to deal with
 * up to 16 Terabyte physical memory. With current x86 CPUs
 * we now support up to 64 Gigabytes physical RAM.
 *
 * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
 */
#ifndef _ASM_HIGHMEM_H
#define _ASM_HIGHMEM_H

#ifdef __KERNEL__

#include <linux/bug.h>
#include <linux/interrupt.h>
#include <linux/uaccess.h>
#include <asm/cpu-features.h>
#include <asm/kmap_types.h>

/* declarations for highmem.c */
extern unsigned long highstart_pfn, highend_pfn;

extern pte_t *pkmap_page_table;

/*
 * Right now we initialize only a single pte table. It can be extended
 * easily, subsequent pte tables have to be allocated in one physical
 * chunk of RAM.
 */
#ifdef CONFIG_PHYS_ADDR_T_64BIT
#define LAST_PKMAP 512
#else
#define LAST_PKMAP 1024
#endif

#define LAST_PKMAP_MASK (LAST_PKMAP-1)
#define PKMAP_NR(virt)	((virt-PKMAP_BASE) >> PAGE_SHIFT)
#define PKMAP_ADDR(nr)	(PKMAP_BASE + ((nr) << PAGE_SHIFT))

#define ARCH_HAS_KMAP_FLUSH_TLB
extern void kmap_flush_tlb(unsigned long addr);
extern void *kmap_atomic(struct page *page);
extern void __kunmap_atomic(void *kvaddr);
extern void *kmap_atomic_pfn(unsigned long pfn);

#define flush_cache_kmaps()	BUG_ON(cpu_has_dc_aliases)

extern void kmap_init(void);

#define kmap_prot PAGE_KERNEL

#endif /* __KERNEL__ */

#endif /* _ASM_HIGHMEM_H */