LXR linux/arch/sparc/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 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 */
  62