OpenCloudOS-Kernel/arch/nds32/include/asm/highmem.h

56 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
// Copyright (C) 2005-2017 Andes Technology Corporation
#ifndef _ASM_HIGHMEM_H
#define _ASM_HIGHMEM_H
#include <asm/proc-fns.h>
#include <asm/kmap_types.h>
#include <asm/fixmap.h>
/*
* 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.
*/
/*
* Ordering is (from lower to higher memory addresses):
*
* high_memory
* Persistent kmap area
* PKMAP_BASE
* fixed_addresses
* FIXADDR_START
* FIXADDR_TOP
* Vmalloc area
* VMALLOC_START
* VMALLOC_END
*/
#define PKMAP_BASE ((FIXADDR_START - PGDIR_SIZE) & (PGDIR_MASK))
#define LAST_PKMAP PTRS_PER_PTE
#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))
static inline void flush_cache_kmaps(void)
{
cpu_dcache_wbinval_all();
}
/* declarations for highmem.c */
extern unsigned long highstart_pfn, highend_pfn;
extern pte_t *pkmap_page_table;
extern void kmap_init(void);
/*
* The following functions are already defined by <linux/highmem.h>
* when CONFIG_HIGHMEM is not set.
*/
#ifdef CONFIG_HIGHMEM
extern void *kmap_atomic_pfn(unsigned long pfn);
#endif
#endif