LXR linux/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 <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 */
  40extern unsigned long __FIXADDR_TOP;
  41#define FIXADDR_TOP     ((unsigned long)__FIXADDR_TOP)
  42
  43#define FIXADDR_USER_START     __fix_to_virt(FIX_VDSO)
  44#define FIXADDR_USER_END       __fix_to_virt(FIX_VDSO - 1)
  45#else
  46#define FIXADDR_TOP     (VSYSCALL_END-PAGE_SIZE)
  47
  48/* Only covers 32bit vsyscalls currently. Need another set for 64bit. */
  49#define FIXADDR_USER_START      ((unsigned long)VSYSCALL32_VSYSCALL)
  50#define FIXADDR_USER_END        (FIXADDR_USER_START + PAGE_SIZE)
  51#endif
  52
  53
  54/*
  55 * Here we define all the compile-time 'special' virtual
  56 * addresses. The point is to have a constant address at
  57 * compile time, but to set the physical address only
  58 * in the boot process.
  59 * for x86_32: We allocate these special addresses
  60 * from the end of virtual memory (0xfffff000) backwards.
  61 * Also this lets us do fail-safe vmalloc(), we
  62 * can guarantee that these special addresses and
  63 * vmalloc()-ed addresses never overlap.
  64 *
  65 * These 'compile-time allocated' memory buffers are
  66 * fixed-size 4k pages (or larger if used with an increment
  67 * higher than 1). Use set_fixmap(idx,phys) to associate
  68 * physical memory with fixmap indices.
  69 *
  70 * TLB entries of such buffers will not be flushed across
  71 * task switches.
  72 */
  73enum fixed_addresses {
  74#ifdef CONFIG_X86_32
  75        FIX_HOLE,
  76        FIX_VDSO,
  77#else
  78        VSYSCALL_LAST_PAGE,
  79        VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE
  80                            + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
  81        VVAR_PAGE,
  82        VSYSCALL_HPET,
  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_VISWS_APIC
  97        FIX_CO_CPU,     /* Cobalt timer */
  98        FIX_CO_APIC,    /* Cobalt APIC Redirection Table */
  99        FIX_LI_PCIA,    /* Lithium PCI Bridge A */
 100        FIX_LI_PCIB,    /* Lithium PCI Bridge B */
 101#endif
 102#ifdef CONFIG_X86_F00F_BUG
 103        FIX_F00F_IDT,   /* Virtual mapping for IDT */
 104#endif
 105#ifdef CONFIG_X86_CYCLONE_TIMER
 106        FIX_CYCLONE_TIMER, /*cyclone timer register*/
 107#endif
 108#ifdef CONFIG_X86_32
 109        FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
 110        FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
 111#ifdef CONFIG_PCI_MMCONFIG
 112        FIX_PCIE_MCFG,
 113#endif
 114#endif
 115#ifdef CONFIG_PARAVIRT
 116        FIX_PARAVIRT_BOOTMAP,
 117#endif
 118        FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */
 119        FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
 120#ifdef  CONFIG_X86_INTEL_MID
 121        FIX_LNW_VRTC,
 122#endif
 123        __end_of_permanent_fixed_addresses,
 124
 125        /*
 126         * 256 temporary boot-time mappings, used by early_ioremap(),
 127         * before ioremap() is functional.
 128         *
 129         * If necessary we round it up to the next 256 pages boundary so
 130         * that we can have a single pgd entry and a single pte table:
 131         */
 132#define NR_FIX_BTMAPS           64
 133#define FIX_BTMAPS_SLOTS        4
 134#define TOTAL_FIX_BTMAPS        (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
 135        FIX_BTMAP_END =
 136         (__end_of_permanent_fixed_addresses ^
 137          (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
 138         -PTRS_PER_PTE
 139         ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
 140           (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
 141         : __end_of_permanent_fixed_addresses,
 142        FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
 143#ifdef CONFIG_X86_32
 144        FIX_WP_TEST,
 145#endif
 146#ifdef CONFIG_INTEL_TXT
 147        FIX_TBOOT_BASE,
 148#endif
 149        __end_of_fixed_addresses
 150};
 151
 152
 153extern void reserve_top_address(unsigned long reserve);
 154
 155#define FIXADDR_SIZE    (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
 156#define FIXADDR_BOOT_SIZE       (__end_of_fixed_addresses << PAGE_SHIFT)
 157#define FIXADDR_START           (FIXADDR_TOP - FIXADDR_SIZE)
 158#define FIXADDR_BOOT_START      (FIXADDR_TOP - FIXADDR_BOOT_SIZE)
 159
 160extern int fixmaps_set;
 161
 162extern pte_t *kmap_pte;
 163extern pgprot_t kmap_prot;
 164extern pte_t *pkmap_page_table;
 165
 166void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
 167void native_set_fixmap(enum fixed_addresses idx,
 168                       phys_addr_t phys, pgprot_t flags);
 169
 170#ifndef CONFIG_PARAVIRT
 171static inline void __set_fixmap(enum fixed_addresses idx,
 172                                phys_addr_t phys, pgprot_t flags)
 173{
 174        native_set_fixmap(idx, phys, flags);
 175}
 176#endif
 177
 178#define set_fixmap(idx, phys)                           \
 179        __set_fixmap(idx, phys, PAGE_KERNEL)
 180
 181/*
 182 * Some hardware wants to get fixmapped without caching.
 183 */
 184#define set_fixmap_nocache(idx, phys)                   \
 185        __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
 186
 187#define clear_fixmap(idx)                       \
 188        __set_fixmap(idx, 0, __pgprot(0))
 189
 190#define __fix_to_virt(x)        (FIXADDR_TOP - ((x) << PAGE_SHIFT))
 191#define __virt_to_fix(x)        ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
 192
 193extern void __this_fixmap_does_not_exist(void);
 194
 195/*
 196 * 'index to address' translation. If anyone tries to use the idx
 197 * directly without translation, we catch the bug with a NULL-deference
 198 * kernel oops. Illegal ranges of incoming indices are caught too.
 199 */
 200static __always_inline unsigned long fix_to_virt(const unsigned int idx)
 201{
 202        /*
 203         * this branch gets completely eliminated after inlining,
 204         * except when someone tries to use fixaddr indices in an
 205         * illegal way. (such as mixing up address types or using
 206         * out-of-range indices).
 207         *
 208         * If it doesn't get removed, the linker will complain
 209         * loudly with a reasonably clear error message..
 210         */
 211        if (idx >= __end_of_fixed_addresses)
 212                __this_fixmap_does_not_exist();
 213
 214        return __fix_to_virt(idx);
 215}
 216
 217static inline unsigned long virt_to_fix(const unsigned long vaddr)
 218{
 219        BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
 220        return __virt_to_fix(vaddr);
 221}
 222
 223/* Return an pointer with offset calculated */
 224static __always_inline unsigned long
 225__set_fixmap_offset(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
 226{
 227        __set_fixmap(idx, phys, flags);
 228        return fix_to_virt(idx) + (phys & (PAGE_SIZE - 1));
 229}
 230
 231#define set_fixmap_offset(idx, phys)                    \
 232        __set_fixmap_offset(idx, phys, PAGE_KERNEL)
 233
 234#define set_fixmap_offset_nocache(idx, phys)                    \
 235        __set_fixmap_offset(idx, phys, PAGE_KERNEL_NOCACHE)
 236
 237#endif /* !__ASSEMBLY__ */
 238#endif /* _ASM_X86_FIXMAP_H */
 239