Viewing file:  highmem.h (1.7 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/* 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_size.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.
*/
#if defined(CONFIG_PHYS_ADDR_T_64BIT) || defined(CONFIG_MIPS_HUGE_TLB_SUPPORT)
#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);
#define flush_cache_kmaps() BUG_ON(cpu_has_dc_aliases)
#define arch_kmap_local_set_pte(mm, vaddr, ptep, ptev) set_pte(ptep, ptev)
#define arch_kmap_local_post_map(vaddr, pteval) local_flush_tlb_one(vaddr)
#define arch_kmap_local_post_unmap(vaddr) local_flush_tlb_one(vaddr)
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */
|