LXR linux/arch/arm64/include/asm/fixmap.h

   1/*
   2 * fixmap.h: compile-time virtual memory allocation
   3 *
   4 * This file is subject to the terms and conditions of the GNU General Public
   5 * License.  See the file "COPYING" in the main directory of this archive
   6 * for more details.
   7 *
   8 * Copyright (C) 1998 Ingo Molnar
   9 * Copyright (C) 2013 Mark Salter <msalter@redhat.com>
  10 *
  11 * Adapted from arch/x86 version.
  12 *
  13 */
  14
  15#ifndef _ASM_ARM64_FIXMAP_H
  16#define _ASM_ARM64_FIXMAP_H
  17
  18#ifndef __ASSEMBLY__
  19#include <linux/kernel.h>
  20#include <linux/sizes.h>
  21#include <asm/boot.h>
  22#include <asm/page.h>
  23#include <asm/pgtable-prot.h>
  24
  25/*
  26 * Here we define all the compile-time 'special' virtual
  27 * addresses. The point is to have a constant address at
  28 * compile time, but to set the physical address only
  29 * in the boot process.
  30 *
  31 * These 'compile-time allocated' memory buffers are
  32 * page-sized. Use set_fixmap(idx,phys) to associate
  33 * physical memory with fixmap indices.
  34 *
  35 */
  36enum fixed_addresses {
  37        FIX_HOLE,
  38
  39        /*
  40         * Reserve a virtual window for the FDT that is 2 MB larger than the
  41         * maximum supported size, and put it at the top of the fixmap region.
  42         * The additional space ensures that any FDT that does not exceed
  43         * MAX_FDT_SIZE can be mapped regardless of whether it crosses any
  44         * 2 MB alignment boundaries.
  45         *
  46         * Keep this at the top so it remains 2 MB aligned.
  47         */
  48#define FIX_FDT_SIZE            (MAX_FDT_SIZE + SZ_2M)
  49        FIX_FDT_END,
  50        FIX_FDT = FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1,
  51
  52        FIX_EARLYCON_MEM_BASE,
  53        FIX_TEXT_POKE0,
  54        __end_of_permanent_fixed_addresses,
  55
  56        /*
  57         * Temporary boot-time mappings, used by early_ioremap(),
  58         * before ioremap() is functional.
  59         */
  60#define NR_FIX_BTMAPS           (SZ_256K / PAGE_SIZE)
  61#define FIX_BTMAPS_SLOTS        7
  62#define TOTAL_FIX_BTMAPS        (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
  63
  64        FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
  65        FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
  66
  67        /*
  68         * Used for kernel page table creation, so unmapped memory may be used
  69         * for tables.
  70         */
  71        FIX_PTE,
  72        FIX_PMD,
  73        FIX_PUD,
  74        FIX_PGD,
  75
  76        __end_of_fixed_addresses
  77};
  78
  79#define FIXADDR_SIZE    (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
  80#define FIXADDR_START   (FIXADDR_TOP - FIXADDR_SIZE)
  81
  82#define FIXMAP_PAGE_IO     __pgprot(PROT_DEVICE_nGnRE)
  83
  84void __init early_fixmap_init(void);
  85
  86#define __early_set_fixmap __set_fixmap
  87
  88#define __late_set_fixmap __set_fixmap
  89#define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR)
  90
  91extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
  92
  93#include <asm-generic/fixmap.h>
  94
  95#endif /* !__ASSEMBLY__ */
  96#endif /* _ASM_ARM64_FIXMAP_H */
  97