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_64 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 <asm/boot.h>
  21 #include <asm/page.h>
  22
  23 /*
  24  * Here we define all the compile-time 'special' virtual
  25  * addresses. The point is to have a constant address at
  26  * compile time, but to set the physical address only
  27  * in the boot process.
  28  *
  29  * These 'compile-time allocated' memory buffers are
  30  * page-sized. Use set_fixmap(idx,phys) to associate
  31  * physical memory with fixmap indices.
  32  *
  33  */
  34 enum fixed_addresses {
  35         FIX_HOLE,
  36
  37         /*
  38          * Reserve a virtual window for the FDT that is 2 MB larger than the
  39          * maximum supported size, and put it at the top of the fixmap region.
  40          * The additional space ensures that any FDT that does not exceed
  41          * MAX_FDT_SIZE can be mapped regardless of whether it crosses any
  42          * 2 MB alignment boundaries.
  43          *
  44          * Keep this at the top so it remains 2 MB aligned.
  45          */
  46 #define FIX_FDT_SIZE            (MAX_FDT_SIZE + SZ_2M)
  47         FIX_FDT_END,
  48         FIX_FDT = FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1,
  49
  50         FIX_EARLYCON_MEM_BASE,
  51         FIX_TEXT_POKE0,
  52         __end_of_permanent_fixed_addresses,
  53
  54         /*
  55          * Temporary boot-time mappings, used by early_ioremap(),
  56          * before ioremap() is functional.
  57          */
  58 #ifdef CONFIG_ARM64_64K_PAGES
  59 #define NR_FIX_BTMAPS           4
  60 #else
  61 #define NR_FIX_BTMAPS           64
  62 #endif
  63 #define FIX_BTMAPS_SLOTS        7
  64 #define TOTAL_FIX_BTMAPS        (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
  65
  66         FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
  67         FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
  68         __end_of_fixed_addresses
  69 };
  70
  71 #define FIXADDR_SIZE    (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
  72 #define FIXADDR_START   (FIXADDR_TOP - FIXADDR_SIZE)
  73
  74 #define FIXMAP_PAGE_IO     __pgprot(PROT_DEVICE_nGnRE)
  75
  76 void __init early_fixmap_init(void);
  77
  78 #define __early_set_fixmap __set_fixmap
  79
  80 #define __late_set_fixmap __set_fixmap
  81 #define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR)
  82
  83 extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
  84
  85 #include <asm-generic/fixmap.h>
  86
  87 #endif /* !__ASSEMBLY__ */
  88 #endif /* _ASM_ARM64_FIXMAP_H */