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/math.h>
  21 #include <linux/sizes.h>
  22 #include <asm/boot.h>
  23 #include <asm/page.h>
  24 #include <asm/pgtable-prot.h>
  25
  26 /*
  27  * Here we define all the compile-time 'special' virtual
  28  * addresses. The point is to have a constant address at
  29  * compile time, but to set the physical address only
  30  * in the boot process.
  31  *
  32  * Each enum increment in these 'compile-time allocated'
  33  * memory buffers is page-sized. Use set_fixmap(idx,phys)
  34  * to associate physical memory with a fixmap index.
  35  */
  36 enum fixed_addresses {
  37         FIX_HOLE,
  38
  39         /*
  40          * Reserve a virtual window for the FDT that is a page bigger than the
  41          * maximum supported size. The additional space ensures that any FDT
  42          * that does not exceed MAX_FDT_SIZE can be mapped regardless of
  43          * whether it crosses any page boundary.
  44          */
  45         FIX_FDT_END,
  46         FIX_FDT = FIX_FDT_END + DIV_ROUND_UP(MAX_FDT_SIZE, PAGE_SIZE) + 1,
  47
  48         FIX_EARLYCON_MEM_BASE,
  49         FIX_TEXT_POKE0,
  50
  51 #ifdef CONFIG_ACPI_APEI_GHES
  52         /* Used for GHES mapping from assorted contexts */
  53         FIX_APEI_GHES_IRQ,
  54         FIX_APEI_GHES_SEA,
  55 #ifdef CONFIG_ARM_SDE_INTERFACE
  56         FIX_APEI_GHES_SDEI_NORMAL,
  57         FIX_APEI_GHES_SDEI_CRITICAL,
  58 #endif
  59 #endif /* CONFIG_ACPI_APEI_GHES */
  60
  61 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
  62 #ifdef CONFIG_RELOCATABLE
  63         FIX_ENTRY_TRAMP_TEXT4,  /* one extra slot for the data page */
  64 #endif
  65         FIX_ENTRY_TRAMP_TEXT3,
  66         FIX_ENTRY_TRAMP_TEXT2,
  67         FIX_ENTRY_TRAMP_TEXT1,
  68 #define TRAMP_VALIAS            (__fix_to_virt(FIX_ENTRY_TRAMP_TEXT1))
  69 #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
  70         __end_of_permanent_fixed_addresses,
  71
  72         /*
  73          * Temporary boot-time mappings, used by early_ioremap(),
  74          * before ioremap() is functional.
  75          */
  76 #define NR_FIX_BTMAPS           (SZ_256K / PAGE_SIZE)
  77 #define FIX_BTMAPS_SLOTS        7
  78 #define TOTAL_FIX_BTMAPS        (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
  79
  80         FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
  81         FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
  82
  83         /*
  84          * Used for kernel page table creation, so unmapped memory may be used
  85          * for tables.
  86          */
  87         FIX_PTE,
  88         FIX_PMD,
  89         FIX_PUD,
  90         FIX_P4D,
  91         FIX_PGD,
  92
  93         __end_of_fixed_addresses
  94 };
  95
  96 #define FIXADDR_SIZE            (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
  97 #define FIXADDR_START           (FIXADDR_TOP - FIXADDR_SIZE)
  98 #define FIXADDR_TOT_SIZE        (__end_of_fixed_addresses << PAGE_SHIFT)
  99 #define FIXADDR_TOT_START       (FIXADDR_TOP - FIXADDR_TOT_SIZE)
 100
 101 #define FIXMAP_PAGE_IO     __pgprot(PROT_DEVICE_nGnRE)
 102
 103 void __init early_fixmap_init(void);
 104
 105 #define __early_set_fixmap __set_fixmap
 106
 107 #define __late_set_fixmap __set_fixmap
 108 #define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR)
 109
 110 extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
 111
 112 #include <asm-generic/fixmap.h>
 113
 114 #endif /* !__ASSEMBLY__ */
 115 #endif /* _ASM_ARM64_FIXMAP_H */