LXR linux/arch/mips/include/asm/highmem.h

   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 Terabyte 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#ifndef _ASM_HIGHMEM_H
  19#define _ASM_HIGHMEM_H
  20
  21#ifdef __KERNEL__
  22
  23#include <linux/bug.h>
  24#include <linux/interrupt.h>
  25#include <linux/uaccess.h>
  26#include <asm/cpu-features.h>
  27#include <asm/kmap_size.h>
  28
  29/* declarations for highmem.c */
  30extern unsigned long highstart_pfn, highend_pfn;
  31
  32extern pte_t *pkmap_page_table;
  33
  34/*
  35 * Right now we initialize only a single pte table. It can be extended
  36 * easily, subsequent pte tables have to be allocated in one physical
  37 * chunk of RAM.
  38 */
  39#if defined(CONFIG_PHYS_ADDR_T_64BIT) || defined(CONFIG_MIPS_HUGE_TLB_SUPPORT)
  40#define LAST_PKMAP 512
  41#else
  42#define LAST_PKMAP 1024
  43#endif
  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 ARCH_HAS_KMAP_FLUSH_TLB
  50extern void kmap_flush_tlb(unsigned long addr);
  51
  52#define flush_cache_kmaps()     BUG_ON(cpu_has_dc_aliases)
  53
  54#define arch_kmap_local_set_pte(mm, vaddr, ptep, ptev)  set_pte(ptep, ptev)
  55#define arch_kmap_local_post_map(vaddr, pteval) local_flush_tlb_one(vaddr)
  56#define arch_kmap_local_post_unmap(vaddr)       local_flush_tlb_one(vaddr)
  57
  58#endif /* __KERNEL__ */
  59
  60#endif /* _ASM_HIGHMEM_H */
  61