1/* SPDX-License-Identifier: GPL-2.0 */
 2/*
 3 * highmem.h: virtual kernel memory mappings for high memory
 4 *
 5 * Used in CONFIG_HIGHMEM systems for memory pages which
 6 * are not addressable by direct kernel virtual addresses.
 7 *
 8 * Copyright (C) 1999 Gerhard Wichert, Siemens AG
 9 *		      Gerhard.Wichert@pdb.siemens.de
10 *
11 *
12 * Redesigned the x86 32-bit VM architecture to deal with 
13 * up to 16 Terrabyte physical memory. With current x86 CPUs
14 * we now support up to 64 Gigabytes physical RAM.
15 *
16 * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
17 */
18
19#ifndef _ASM_HIGHMEM_H
20#define _ASM_HIGHMEM_H
21
22#ifdef __KERNEL__
23
24#include <linux/interrupt.h>
25#include <linux/pgtable.h>
26#include <asm/vaddrs.h>
27#include <asm/pgtsrmmu.h>
 
28
29/* declarations for highmem.c */
30extern unsigned long highstart_pfn, highend_pfn;
31
32#define kmap_prot __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE)
33extern pte_t *pkmap_page_table;
34
 
 
35/*
36 * Right now we initialize only a single pte table. It can be extended
37 * easily, subsequent pte tables have to be allocated in one physical
38 * chunk of RAM.  Currently the simplest way to do this is to align the
39 * pkmap region on a pagetable boundary (4MB).
40 */
41#define LAST_PKMAP 1024
42#define PKMAP_SIZE (LAST_PKMAP << PAGE_SHIFT)
43#define PKMAP_BASE PMD_ALIGN(SRMMU_NOCACHE_VADDR + (SRMMU_MAX_NOCACHE_PAGES << PAGE_SHIFT))
44
45#define LAST_PKMAP_MASK (LAST_PKMAP - 1)
46#define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
47#define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
48
49#define PKMAP_END (PKMAP_ADDR(LAST_PKMAP))
50
51#define flush_cache_kmaps()	flush_cache_all()
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
52
53/* FIXME: Use __flush_*_one(vaddr) instead of flush_*_all() -- Anton */
54#define arch_kmap_local_pre_map(vaddr, pteval)	flush_cache_all()
55#define arch_kmap_local_pre_unmap(vaddr)	flush_cache_all()
56#define arch_kmap_local_post_map(vaddr, pteval)	flush_tlb_all()
57#define arch_kmap_local_post_unmap(vaddr)	flush_tlb_all()
58
59#endif /* __KERNEL__ */
60
61#endif /* _ASM_HIGHMEM_H */

 
 1/*
 2 * highmem.h: virtual kernel memory mappings for high memory
 3 *
 4 * Used in CONFIG_HIGHMEM systems for memory pages which
 5 * are not addressable by direct kernel virtual addresses.
 6 *
 7 * Copyright (C) 1999 Gerhard Wichert, Siemens AG
 8 *		      Gerhard.Wichert@pdb.siemens.de
 9 *
10 *
11 * Redesigned the x86 32-bit VM architecture to deal with 
12 * up to 16 Terrabyte physical memory. With current x86 CPUs
13 * we now support up to 64 Gigabytes physical RAM.
14 *
15 * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
16 */
17
18#ifndef _ASM_HIGHMEM_H
19#define _ASM_HIGHMEM_H
20
21#ifdef __KERNEL__
22
23#include <linux/interrupt.h>
 
24#include <asm/vaddrs.h>
25#include <asm/kmap_types.h>
26#include <asm/pgtable.h>
27
28/* declarations for highmem.c */
29extern unsigned long highstart_pfn, highend_pfn;
30
31extern pgprot_t kmap_prot;
32extern pte_t *pkmap_page_table;
33
34void kmap_init(void) __init;
35
36/*
37 * Right now we initialize only a single pte table. It can be extended
38 * easily, subsequent pte tables have to be allocated in one physical
39 * chunk of RAM.  Currently the simplest way to do this is to align the
40 * pkmap region on a pagetable boundary (4MB).
41 */
42#define LAST_PKMAP 1024
43#define PKMAP_SIZE (LAST_PKMAP << PAGE_SHIFT)
44#define PKMAP_BASE PMD_ALIGN(SRMMU_NOCACHE_VADDR + (SRMMU_MAX_NOCACHE_PAGES << PAGE_SHIFT))
45
46#define LAST_PKMAP_MASK (LAST_PKMAP - 1)
47#define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
48#define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
49
50#define PKMAP_END (PKMAP_ADDR(LAST_PKMAP))
51
52void *kmap_high(struct page *page);
53void kunmap_high(struct page *page);
54
55static inline void *kmap(struct page *page)
56{
57	BUG_ON(in_interrupt());
58	if (!PageHighMem(page))
59		return page_address(page);
60	return kmap_high(page);
61}
62
63static inline void kunmap(struct page *page)
64{
65	BUG_ON(in_interrupt());
66	if (!PageHighMem(page))
67		return;
68	kunmap_high(page);
69}
70
71void *kmap_atomic(struct page *page);
72void __kunmap_atomic(void *kvaddr);
73
74#define flush_cache_kmaps()	flush_cache_all()
 
75
76#endif /* __KERNEL__ */
77
78#endif /* _ASM_HIGHMEM_H */