arch/microblaze/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/init.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/uaccess.h>
  26 #include <asm/fixmap.h>
  27
  28 extern pte_t *pkmap_page_table;
  29
  30 /*
  31  * Right now we initialize only a single pte table. It can be extended
  32  * easily, subsequent pte tables have to be allocated in one physical
  33  * chunk of RAM.
  34  */
  35 /*
  36  * We use one full pte table with 4K pages. And with 16K/64K/256K pages pte
  37  * table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP
  38  * and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP
  39  * in case of 16K/64K/256K page sizes.
  40  */
  41
  42 #define PKMAP_ORDER     PTE_SHIFT
  43 #define LAST_PKMAP      (1 << PKMAP_ORDER)
  44
  45 #define PKMAP_BASE      ((FIXADDR_START - PAGE_SIZE * (LAST_PKMAP + 1)) \
  46                                                                 & PMD_MASK)
  47
  48 #define LAST_PKMAP_MASK (LAST_PKMAP - 1)
  49 #define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
  50 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
  51
  52 #define flush_cache_kmaps()     { flush_icache(); flush_dcache(); }
  53
  54 #define arch_kmap_local_post_map(vaddr, pteval) \
  55         local_flush_tlb_page(NULL, vaddr);
  56 #define arch_kmap_local_post_unmap(vaddr)       \
  57         local_flush_tlb_page(NULL, vaddr);
  58
  59 #endif /* __KERNEL__ */
  60
  61 #endif /* _ASM_HIGHMEM_H */