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 #include <asm/pvclock.h>
  23 #ifdef CONFIG_X86_32
  24 #include <linux/threads.h>
  25 #include <asm/kmap_types.h>
  26 #else
  27 #include <uapi/asm/vsyscall.h>
  28 #endif
  29
  30 /*
  31  * We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall
  32  * uses fixmaps that relies on FIXADDR_TOP for proper address calculation.
  33  * Because of this, FIXADDR_TOP x86 integration was left as later work.
  34  */
  35 #ifdef CONFIG_X86_32
  36 /* used by vmalloc.c, vsyscall.lds.S.
  37  *
  38  * Leave one empty page between vmalloc'ed areas and
  39  * the start of the fixmap.
  40  */
  41 extern unsigned long __FIXADDR_TOP;
  42 #define FIXADDR_TOP     ((unsigned long)__FIXADDR_TOP)
  43 #else
  44 #define FIXADDR_TOP     (round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
  45                          PAGE_SIZE)
  46 #endif
  47
  48
  49 /*
  50  * Here we define all the compile-time 'special' virtual
  51  * addresses. The point is to have a constant address at
  52  * compile time, but to set the physical address only
  53  * in the boot process.
  54  * for x86_32: We allocate these special addresses
  55  * from the end of virtual memory (0xfffff000) backwards.
  56  * Also this lets us do fail-safe vmalloc(), we
  57  * can guarantee that these special addresses and
  58  * vmalloc()-ed addresses never overlap.
  59  *
  60  * These 'compile-time allocated' memory buffers are
  61  * fixed-size 4k pages (or larger if used with an increment
  62  * higher than 1). Use set_fixmap(idx,phys) to associate
  63  * physical memory with fixmap indices.
  64  *
  65  * TLB entries of such buffers will not be flushed across
  66  * task switches.
  67  */
  68 enum fixed_addresses {
  69 #ifdef CONFIG_X86_32
  70         FIX_HOLE,
  71 #else
  72         VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
  73 #ifdef CONFIG_PARAVIRT_CLOCK
  74         PVCLOCK_FIXMAP_BEGIN,
  75         PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1,
  76 #endif
  77 #endif
  78         FIX_DBGP_BASE,
  79         FIX_EARLYCON_MEM_BASE,
  80 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
  81         FIX_OHCI1394_BASE,
  82 #endif
  83 #ifdef CONFIG_X86_LOCAL_APIC
  84         FIX_APIC_BASE,  /* local (CPU) APIC) -- required for SMP or not */
  85 #endif
  86 #ifdef CONFIG_X86_IO_APIC
  87         FIX_IO_APIC_BASE_0,
  88         FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
  89 #endif
  90         FIX_RO_IDT,     /* Virtual mapping for read-only IDT */
  91 #ifdef CONFIG_X86_32
  92         FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
  93         FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
  94 #ifdef CONFIG_PCI_MMCONFIG
  95         FIX_PCIE_MCFG,
  96 #endif
  97 #endif
  98 #ifdef CONFIG_PARAVIRT
  99         FIX_PARAVIRT_BOOTMAP,
 100 #endif
 101         FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */
 102         FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
 103 #ifdef  CONFIG_X86_INTEL_MID
 104         FIX_LNW_VRTC,
 105 #endif
 106         __end_of_permanent_fixed_addresses,
 107
 108         /*
 109          * 256 temporary boot-time mappings, used by early_ioremap(),
 110          * before ioremap() is functional.
 111          *
 112          * If necessary we round it up to the next 256 pages boundary so
 113          * that we can have a single pgd entry and a single pte table:
 114          */
 115 #define NR_FIX_BTMAPS           64
 116 #define FIX_BTMAPS_SLOTS        4
 117 #define TOTAL_FIX_BTMAPS        (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
 118         FIX_BTMAP_END =
 119          (__end_of_permanent_fixed_addresses ^
 120           (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
 121          -PTRS_PER_PTE
 122          ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
 123            (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
 124          : __end_of_permanent_fixed_addresses,
 125         FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
 126 #ifdef CONFIG_X86_32
 127         FIX_WP_TEST,
 128 #endif
 129 #ifdef CONFIG_INTEL_TXT
 130         FIX_TBOOT_BASE,
 131 #endif
 132         __end_of_fixed_addresses
 133 };
 134
 135
 136 extern void reserve_top_address(unsigned long reserve);
 137
 138 #define FIXADDR_SIZE    (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
 139 #define FIXADDR_BOOT_SIZE       (__end_of_fixed_addresses << PAGE_SHIFT)
 140 #define FIXADDR_START           (FIXADDR_TOP - FIXADDR_SIZE)
 141 #define FIXADDR_BOOT_START      (FIXADDR_TOP - FIXADDR_BOOT_SIZE)
 142
 143 extern int fixmaps_set;
 144
 145 extern pte_t *kmap_pte;
 146 extern pgprot_t kmap_prot;
 147 extern pte_t *pkmap_page_table;
 148
 149 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
 150 void native_set_fixmap(enum fixed_addresses idx,
 151                        phys_addr_t phys, pgprot_t flags);
 152
 153 #ifndef CONFIG_PARAVIRT
 154 static inline void __set_fixmap(enum fixed_addresses idx,
 155                                 phys_addr_t phys, pgprot_t flags)
 156 {
 157         native_set_fixmap(idx, phys, flags);
 158 }
 159 #endif
 160
 161 #include <asm-generic/fixmap.h>
 162
 163 #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags)
 164 #define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0))
 165
 166 void __early_set_fixmap(enum fixed_addresses idx,
 167                         phys_addr_t phys, pgprot_t flags);
 168
 169 #endif /* !__ASSEMBLY__ */
 170 #endif /* _ASM_X86_FIXMAP_H */