arch/x86/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  *
  10  * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
  11  * x86_32 and x86_64 integration by Gustavo F. Padovan, February 2009
  12  */
  13
  14 #ifndef _ASM_X86_FIXMAP_H
  15 #define _ASM_X86_FIXMAP_H
  16
  17 /*
  18  * Exposed to assembly code for setting up initial page tables. Cannot be
  19  * calculated in assembly code (fixmap entries are an enum), but is sanity
  20  * checked in the actual fixmap C code to make sure that the fixmap is
  21  * covered fully.
  22  */
  23 #define FIXMAP_PMD_NUM  2
  24 /* fixmap starts downwards from the 507th entry in level2_fixmap_pgt */
  25 #define FIXMAP_PMD_TOP  507
  26
  27 #ifndef __ASSEMBLY__
  28 #include <linux/kernel.h>
  29 #include <asm/acpi.h>
  30 #include <asm/apicdef.h>
  31 #include <asm/page.h>
  32 #ifdef CONFIG_X86_32
  33 #include <linux/threads.h>
  34 #include <asm/kmap_types.h>
  35 #else
  36 #include <uapi/asm/vsyscall.h>
  37 #endif
  38
  39 /*
  40  * We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall
  41  * uses fixmaps that relies on FIXADDR_TOP for proper address calculation.
  42  * Because of this, FIXADDR_TOP x86 integration was left as later work.
  43  */
  44 #ifdef CONFIG_X86_32
  45 /* used by vmalloc.c, vsyscall.lds.S.
  46  *
  47  * Leave one empty page between vmalloc'ed areas and
  48  * the start of the fixmap.
  49  */
  50 extern unsigned long __FIXADDR_TOP;
  51 #define FIXADDR_TOP     ((unsigned long)__FIXADDR_TOP)
  52 #else
  53 #define FIXADDR_TOP     (round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
  54                          PAGE_SIZE)
  55 #endif
  56
  57 /*
  58  * Here we define all the compile-time 'special' virtual
  59  * addresses. The point is to have a constant address at
  60  * compile time, but to set the physical address only
  61  * in the boot process.
  62  * for x86_32: We allocate these special addresses
  63  * from the end of virtual memory (0xfffff000) backwards.
  64  * Also this lets us do fail-safe vmalloc(), we
  65  * can guarantee that these special addresses and
  66  * vmalloc()-ed addresses never overlap.
  67  *
  68  * These 'compile-time allocated' memory buffers are
  69  * fixed-size 4k pages (or larger if used with an increment
  70  * higher than 1). Use set_fixmap(idx,phys) to associate
  71  * physical memory with fixmap indices.
  72  *
  73  * TLB entries of such buffers will not be flushed across
  74  * task switches.
  75  */
  76 enum fixed_addresses {
  77 #ifdef CONFIG_X86_32
  78         FIX_HOLE,
  79 #else
  80 #ifdef CONFIG_X86_VSYSCALL_EMULATION
  81         VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
  82 #endif
  83 #endif
  84         FIX_DBGP_BASE,
  85         FIX_EARLYCON_MEM_BASE,
  86 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
  87         FIX_OHCI1394_BASE,
  88 #endif
  89 #ifdef CONFIG_X86_LOCAL_APIC
  90         FIX_APIC_BASE,  /* local (CPU) APIC) -- required for SMP or not */
  91 #endif
  92 #ifdef CONFIG_X86_IO_APIC
  93         FIX_IO_APIC_BASE_0,
  94         FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
  95 #endif
  96 #ifdef CONFIG_X86_32
  97         FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
  98         FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
  99 #ifdef CONFIG_PCI_MMCONFIG
 100         FIX_PCIE_MCFG,
 101 #endif
 102 #endif
 103 #ifdef CONFIG_PARAVIRT
 104         FIX_PARAVIRT_BOOTMAP,
 105 #endif
 106         FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */
 107         FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
 108 #ifdef  CONFIG_X86_INTEL_MID
 109         FIX_LNW_VRTC,
 110 #endif
 111
 112 #ifdef CONFIG_ACPI_APEI_GHES
 113         /* Used for GHES mapping from assorted contexts */
 114         FIX_APEI_GHES_IRQ,
 115         FIX_APEI_GHES_NMI,
 116 #endif
 117
 118         __end_of_permanent_fixed_addresses,
 119
 120         /*
 121          * 512 temporary boot-time mappings, used by early_ioremap(),
 122          * before ioremap() is functional.
 123          *
 124          * If necessary we round it up to the next 512 pages boundary so
 125          * that we can have a single pgd entry and a single pte table:
 126          */
 127 #define NR_FIX_BTMAPS           64
 128 #define FIX_BTMAPS_SLOTS        8
 129 #define TOTAL_FIX_BTMAPS        (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
 130         FIX_BTMAP_END =
 131          (__end_of_permanent_fixed_addresses ^
 132           (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
 133          -PTRS_PER_PTE
 134          ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
 135            (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
 136          : __end_of_permanent_fixed_addresses,
 137         FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
 138 #ifdef CONFIG_X86_32
 139         FIX_WP_TEST,
 140 #endif
 141 #ifdef CONFIG_INTEL_TXT
 142         FIX_TBOOT_BASE,
 143 #endif
 144         __end_of_fixed_addresses
 145 };
 146
 147
 148 extern void reserve_top_address(unsigned long reserve);
 149
 150 #define FIXADDR_SIZE            (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
 151 #define FIXADDR_START           (FIXADDR_TOP - FIXADDR_SIZE)
 152 #define FIXADDR_TOT_SIZE        (__end_of_fixed_addresses << PAGE_SHIFT)
 153 #define FIXADDR_TOT_START       (FIXADDR_TOP - FIXADDR_TOT_SIZE)
 154
 155 extern int fixmaps_set;
 156
 157 extern pte_t *kmap_pte;
 158 #define kmap_prot PAGE_KERNEL
 159 extern pte_t *pkmap_page_table;
 160
 161 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
 162 void native_set_fixmap(enum fixed_addresses idx,
 163                        phys_addr_t phys, pgprot_t flags);
 164
 165 #ifndef CONFIG_PARAVIRT
 166 static inline void __set_fixmap(enum fixed_addresses idx,
 167                                 phys_addr_t phys, pgprot_t flags)
 168 {
 169         native_set_fixmap(idx, phys, flags);
 170 }
 171 #endif
 172
 173 /*
 174  * FIXMAP_PAGE_NOCACHE is used for MMIO. Memory encryption is not
 175  * supported for MMIO addresses, so make sure that the memory encryption
 176  * mask is not part of the page attributes.
 177  */
 178 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE
 179
 180 /*
 181  * Early memremap routines used for in-place encryption. The mappings created
 182  * by these routines are intended to be used as temporary mappings.
 183  */
 184 void __init *early_memremap_encrypted(resource_size_t phys_addr,
 185                                       unsigned long size);
 186 void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
 187                                          unsigned long size);
 188 void __init *early_memremap_decrypted(resource_size_t phys_addr,
 189                                       unsigned long size);
 190 void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
 191                                          unsigned long size);
 192
 193 #include <asm-generic/fixmap.h>
 194
 195 #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags)
 196 #define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0))
 197
 198 void __early_set_fixmap(enum fixed_addresses idx,
 199                         phys_addr_t phys, pgprot_t flags);
 200
 201 #endif /* !__ASSEMBLY__ */
 202 #endif /* _ASM_X86_FIXMAP_H */