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

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * highmem.h: virtual kernel memory mappings for high memory
   4 *
   5 * PowerPC version, stolen from the i386 version.
   6 *
   7 * Used in CONFIG_HIGHMEM systems for memory pages which
   8 * are not addressable by direct kernel virtual addresses.
   9 *
  10 * Copyright (C) 1999 Gerhard Wichert, Siemens AG
  11 *                    Gerhard.Wichert@pdb.siemens.de
  12 *
  13 *
  14 * Redesigned the x86 32-bit VM architecture to deal with
  15 * up to 16 Terrabyte physical memory. With current x86 CPUs
  16 * we now support up to 64 Gigabytes physical RAM.
  17 *
  18 * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
  19 */
  20
  21#ifndef _ASM_HIGHMEM_H
  22#define _ASM_HIGHMEM_H
  23
  24#ifdef __KERNEL__
  25
  26#include <linux/interrupt.h>
  27#include <asm/cacheflush.h>
  28#include <asm/page.h>
  29#include <asm/fixmap.h>
  30
  31extern pte_t *pkmap_page_table;
  32
  33/*
  34 * Right now we initialize only a single pte table. It can be extended
  35 * easily, subsequent pte tables have to be allocated in one physical
  36 * chunk of RAM.
  37 */
  38/*
  39 * We use one full pte table with 4K pages. And with 16K/64K/256K pages pte
  40 * table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP
  41 * and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP
  42 * in case of 16K/64K/256K page sizes.
  43 */
  44#ifdef CONFIG_PPC_4K_PAGES
  45#define PKMAP_ORDER     PTE_SHIFT
  46#else
  47#define PKMAP_ORDER     9
  48#endif
  49#define LAST_PKMAP      (1 << PKMAP_ORDER)
  50#ifndef CONFIG_PPC_4K_PAGES
  51#define PKMAP_BASE      (FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1))
  52#else
  53#define PKMAP_BASE      ((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK)
  54#endif
  55#define LAST_PKMAP_MASK (LAST_PKMAP-1)
  56#define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
  57#define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
  58
  59#define flush_cache_kmaps()     flush_cache_all()
  60
  61#define arch_kmap_local_set_pte(mm, vaddr, ptep, ptev)  \
  62        __set_pte_at(mm, vaddr, ptep, ptev, 1)
  63#define arch_kmap_local_post_map(vaddr, pteval) \
  64        local_flush_tlb_page(NULL, vaddr)
  65#define arch_kmap_local_post_unmap(vaddr)       \
  66        local_flush_tlb_page(NULL, vaddr)
  67
  68#endif /* __KERNEL__ */
  69
  70#endif /* _ASM_HIGHMEM_H */
  71