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 #ifndef __ASSEMBLY__
  18 #include <linux/kernel.h>
  19 #include <asm/acpi.h>
  20 #include <asm/apicdef.h>
  21 #include <asm/page.h>
  22 #ifdef CONFIG_X86_32
  23 #include <linux/threads.h>
  24 #include <asm/kmap_types.h>
  25 #else
  26 #include <uapi/asm/vsyscall.h>
  27 #endif
  28
  29 /*
  30  * We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall
  31  * uses fixmaps that relies on FIXADDR_TOP for proper address calculation.
  32  * Because of this, FIXADDR_TOP x86 integration was left as later work.
  33  */
  34 #ifdef CONFIG_X86_32
  35 /* used by vmalloc.c, vsyscall.lds.S.
  36  *
  37  * Leave one empty page between vmalloc'ed areas and
  38  * the start of the fixmap.
  39  */
  40 extern unsigned long __FIXADDR_TOP;
  41 #define FIXADDR_TOP     ((unsigned long)__FIXADDR_TOP)
  42 #else
  43 #define FIXADDR_TOP     (round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
  44                          PAGE_SIZE)
  45 #endif
  46
  47
  48 /*
  49  * Here we define all the compile-time 'special' virtual
  50  * addresses. The point is to have a constant address at
  51  * compile time, but to set the physical address only
  52  * in the boot process.
  53  * for x86_32: We allocate these special addresses
  54  * from the end of virtual memory (0xfffff000) backwards.
  55  * Also this lets us do fail-safe vmalloc(), we
  56  * can guarantee that these special addresses and
  57  * vmalloc()-ed addresses never overlap.
  58  *
  59  * These 'compile-time allocated' memory buffers are
  60  * fixed-size 4k pages (or larger if used with an increment
  61  * higher than 1). Use set_fixmap(idx,phys) to associate
  62  * physical memory with fixmap indices.
  63  *
  64  * TLB entries of such buffers will not be flushed across
  65  * task switches.
  66  */
  67 enum fixed_addresses {
  68 #ifdef CONFIG_X86_32
  69         FIX_HOLE,
  70 #else
  71 #ifdef CONFIG_X86_VSYSCALL_EMULATION
  72         VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
  73 #endif
  74 #endif
  75         FIX_DBGP_BASE,
  76         FIX_EARLYCON_MEM_BASE,
  77 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
  78         FIX_OHCI1394_BASE,
  79 #endif
  80 #ifdef CONFIG_X86_LOCAL_APIC
  81         FIX_APIC_BASE,  /* local (CPU) APIC) -- required for SMP or not */
  82 #endif
  83 #ifdef CONFIG_X86_IO_APIC
  84         FIX_IO_APIC_BASE_0,
  85         FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
  86 #endif
  87         FIX_RO_IDT,     /* Virtual mapping for read-only IDT */
  88 #ifdef CONFIG_X86_32
  89         FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
  90         FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
  91 #ifdef CONFIG_PCI_MMCONFIG
  92         FIX_PCIE_MCFG,
  93 #endif
  94 #endif
  95 #ifdef CONFIG_PARAVIRT
  96         FIX_PARAVIRT_BOOTMAP,
  97 #endif
  98         FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */
  99         FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
 100 #ifdef  CONFIG_X86_INTEL_MID
 101         FIX_LNW_VRTC,
 102 #endif
 103         __end_of_permanent_fixed_addresses,
 104
 105         /*
 106          * 512 temporary boot-time mappings, used by early_ioremap(),
 107          * before ioremap() is functional.
 108          *
 109          * If necessary we round it up to the next 512 pages boundary so
 110          * that we can have a single pgd entry and a single pte table:
 111          */
 112 #define NR_FIX_BTMAPS           64
 113 #define FIX_BTMAPS_SLOTS        8
 114 #define TOTAL_FIX_BTMAPS        (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
 115         FIX_BTMAP_END =
 116          (__end_of_permanent_fixed_addresses ^
 117           (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
 118          -PTRS_PER_PTE
 119          ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
 120            (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
 121          : __end_of_permanent_fixed_addresses,
 122         FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
 123 #ifdef CONFIG_X86_32
 124         FIX_WP_TEST,
 125 #endif
 126 #ifdef CONFIG_INTEL_TXT
 127         FIX_TBOOT_BASE,
 128 #endif
 129         __end_of_fixed_addresses
 130 };
 131
 132
 133 extern void reserve_top_address(unsigned long reserve);
 134
 135 #define FIXADDR_SIZE    (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
 136 #define FIXADDR_START           (FIXADDR_TOP - FIXADDR_SIZE)
 137
 138 extern int fixmaps_set;
 139
 140 extern pte_t *kmap_pte;
 141 #define kmap_prot PAGE_KERNEL
 142 extern pte_t *pkmap_page_table;
 143
 144 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
 145 void native_set_fixmap(enum fixed_addresses idx,
 146                        phys_addr_t phys, pgprot_t flags);
 147
 148 #ifndef CONFIG_PARAVIRT
 149 static inline void __set_fixmap(enum fixed_addresses idx,
 150                                 phys_addr_t phys, pgprot_t flags)
 151 {
 152         native_set_fixmap(idx, phys, flags);
 153 }
 154 #endif
 155
 156 #include <asm-generic/fixmap.h>
 157
 158 #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags)
 159 #define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0))
 160
 161 void __early_set_fixmap(enum fixed_addresses idx,
 162                         phys_addr_t phys, pgprot_t flags);
 163
 164 #endif /* !__ASSEMBLY__ */
 165 #endif /* _ASM_X86_FIXMAP_H */