67 lines
1.7 KiB
C
67 lines
1.7 KiB
C
/* 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))
|
|
|
|
extern void * kmap_high(struct page *page);
|
|
extern void kunmap_high(struct page *page);
|
|
|
|
extern void *kmap(struct page *page);
|
|
extern void kunmap(struct page *page);
|
|
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 */
|