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#include <asm/pvclock.h>
  23#ifdef CONFIG_X86_32
  24#include <linux/threads.h>
  25#include <asm/kmap_types.h>
  26#else
  27#include <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 */
  41extern unsigned long __FIXADDR_TOP;
  42#define FIXADDR_TOP     ((unsigned long)__FIXADDR_TOP)
  43
  44#define FIXADDR_USER_START     __fix_to_virt(FIX_VDSO)
  45#define FIXADDR_USER_END       __fix_to_virt(FIX_VDSO - 1)
  46#else
  47#define FIXADDR_TOP     (VSYSCALL_END-PAGE_SIZE)
  48
  49/* Only covers 32bit vsyscalls currently. Need another set for 64bit. */
  50#define FIXADDR_USER_START      ((unsigned long)VSYSCALL32_VSYSCALL)
  51#define FIXADDR_USER_END        (FIXADDR_USER_START + PAGE_SIZE)
  52#endif
  53
  54
  55/*
  56 * Here we define all the compile-time 'special' virtual
  57 * addresses. The point is to have a constant address at
  58 * compile time, but to set the physical address only
  59 * in the boot process.
  60 * for x86_32: We allocate these special addresses
  61 * from the end of virtual memory (0xfffff000) backwards.
  62 * Also this lets us do fail-safe vmalloc(), we
  63 * can guarantee that these special addresses and
  64 * vmalloc()-ed addresses never overlap.
  65 *
  66 * These 'compile-time allocated' memory buffers are
  67 * fixed-size 4k pages (or larger if used with an increment
  68 * higher than 1). Use set_fixmap(idx,phys) to associate
  69 * physical memory with fixmap indices.
  70 *
  71 * TLB entries of such buffers will not be flushed across
  72 * task switches.
  73 */
  74enum fixed_addresses {
  75#ifdef CONFIG_X86_32
  76        FIX_HOLE,
  77        FIX_VDSO,
  78#else
  79        VSYSCALL_LAST_PAGE,
  80        VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE
  81                            + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
  82        VVAR_PAGE,
  83        VSYSCALL_HPET,
  84#endif
  85#ifdef CONFIG_PARAVIRT_CLOCK
  86        PVCLOCK_FIXMAP_BEGIN,
  87        PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1,
  88#endif
  89#ifdef CONFIG_HYPERV_TSCPAGE
  90        HVCLOCK_TSC_PAGE,
  91#endif
  92        FIX_DBGP_BASE,
  93        FIX_EARLYCON_MEM_BASE,
  94#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
  95        FIX_OHCI1394_BASE,
  96#endif
  97#ifdef CONFIG_X86_LOCAL_APIC
  98        FIX_APIC_BASE,  /* local (CPU) APIC) -- required for SMP or not */
  99#endif
 100#ifdef CONFIG_X86_IO_APIC
 101        FIX_IO_APIC_BASE_0,
 102        FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
 103#endif
 104#ifdef CONFIG_X86_VISWS_APIC
 105        FIX_CO_CPU,     /* Cobalt timer */
 106        FIX_CO_APIC,    /* Cobalt APIC Redirection Table */
 107        FIX_LI_PCIA,    /* Lithium PCI Bridge A */
 108        FIX_LI_PCIB,    /* Lithium PCI Bridge B */
 109#endif
 110        FIX_RO_IDT,     /* Virtual mapping for read-only IDT */
 111#ifdef CONFIG_X86_32
 112        FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
 113        FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
 114#ifdef CONFIG_PCI_MMCONFIG
 115        FIX_PCIE_MCFG,
 116#endif
 117#endif
 118#ifdef CONFIG_PARAVIRT
 119        FIX_PARAVIRT_BOOTMAP,
 120#endif
 121        FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */
 122        FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
 123#ifdef  CONFIG_X86_INTEL_MID
 124        FIX_LNW_VRTC,
 125#endif
 126        __end_of_permanent_fixed_addresses,
 127
 128        /*
 129         * 512 temporary boot-time mappings, used by early_ioremap(),
 130         * before ioremap() is functional.
 131         *
 132         * If necessary we round it up to the next 512 pages boundary so
 133         * that we can have a single pgd entry and a single pte table:
 134         */
 135#define NR_FIX_BTMAPS           64
 136#define FIX_BTMAPS_SLOTS        8
 137#define TOTAL_FIX_BTMAPS        (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
 138        FIX_BTMAP_END =
 139         (__end_of_permanent_fixed_addresses ^
 140          (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
 141         -PTRS_PER_PTE
 142         ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
 143           (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
 144         : __end_of_permanent_fixed_addresses,
 145        FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
 146#ifdef CONFIG_X86_32
 147        FIX_WP_TEST,
 148#endif
 149#ifdef CONFIG_INTEL_TXT
 150        FIX_TBOOT_BASE,
 151#endif
 152        __end_of_fixed_addresses
 153};
 154
 155
 156extern void reserve_top_address(unsigned long reserve);
 157
 158#define FIXADDR_SIZE    (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
 159#define FIXADDR_BOOT_SIZE       (__end_of_fixed_addresses << PAGE_SHIFT)
 160#define FIXADDR_START           (FIXADDR_TOP - FIXADDR_SIZE)
 161#define FIXADDR_BOOT_START      (FIXADDR_TOP - FIXADDR_BOOT_SIZE)
 162
 163extern int fixmaps_set;
 164
 165extern pte_t *kmap_pte;
 166extern pgprot_t kmap_prot;
 167extern pte_t *pkmap_page_table;
 168
 169void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
 170void native_set_fixmap(enum fixed_addresses idx,
 171                       phys_addr_t phys, pgprot_t flags);
 172
 173#ifndef CONFIG_PARAVIRT
 174static inline void __set_fixmap(enum fixed_addresses idx,
 175                                phys_addr_t phys, pgprot_t flags)
 176{
 177        native_set_fixmap(idx, phys, flags);
 178}
 179#endif
 180
 181/*
 182 * FIXMAP_PAGE_NOCACHE is used for MMIO. Memory encryption is not
 183 * supported for MMIO addresses, so make sure that the memory encryption
 184 * mask is not part of the page attributes.
 185 */
 186#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE
 187
 188/*
 189 * Early memremap routines used for in-place encryption. The mappings created
 190 * by these routines are intended to be used as temporary mappings.
 191 */
 192void __init *early_memremap_encrypted(resource_size_t phys_addr,
 193                                      unsigned long size);
 194void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
 195                                         unsigned long size);
 196void __init *early_memremap_decrypted(resource_size_t phys_addr,
 197                                      unsigned long size);
 198void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
 199                                         unsigned long size);
 200
 201#define set_fixmap(idx, phys)                           \
 202        __set_fixmap(idx, phys, PAGE_KERNEL)
 203
 204/*
 205 * Some hardware wants to get fixmapped without caching.
 206 */
 207#define set_fixmap_nocache(idx, phys)                   \
 208        __set_fixmap(idx, phys, FIXMAP_PAGE_NOCACHE)
 209
 210/*
 211 * Some fixmaps are for IO
 212 */
 213#define set_fixmap_io(idx, phys)                        \
 214        __set_fixmap(idx, phys, PAGE_KERNEL_IO)
 215
 216#define clear_fixmap(idx)                       \
 217        __set_fixmap(idx, 0, __pgprot(0))
 218
 219#define __fix_to_virt(x)        (FIXADDR_TOP - ((x) << PAGE_SHIFT))
 220#define __virt_to_fix(x)        ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
 221
 222extern void __this_fixmap_does_not_exist(void);
 223
 224/*
 225 * 'index to address' translation. If anyone tries to use the idx
 226 * directly without translation, we catch the bug with a NULL-deference
 227 * kernel oops. Illegal ranges of incoming indices are caught too.
 228 */
 229static __always_inline unsigned long fix_to_virt(const unsigned int idx)
 230{
 231        /*
 232         * this branch gets completely eliminated after inlining,
 233         * except when someone tries to use fixaddr indices in an
 234         * illegal way. (such as mixing up address types or using
 235         * out-of-range indices).
 236         *
 237         * If it doesn't get removed, the linker will complain
 238         * loudly with a reasonably clear error message..
 239         */
 240        if (idx >= __end_of_fixed_addresses)
 241                __this_fixmap_does_not_exist();
 242
 243        return __fix_to_virt(idx);
 244}
 245
 246static inline unsigned long virt_to_fix(const unsigned long vaddr)
 247{
 248        BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
 249        return __virt_to_fix(vaddr);
 250}
 251
 252/* Return an pointer with offset calculated */
 253static __always_inline unsigned long
 254__set_fixmap_offset(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
 255{
 256        __set_fixmap(idx, phys, flags);
 257        return fix_to_virt(idx) + (phys & (PAGE_SIZE - 1));
 258}
 259
 260#define set_fixmap_offset(idx, phys)                    \
 261        __set_fixmap_offset(idx, phys, PAGE_KERNEL)
 262
 263#define set_fixmap_offset_nocache(idx, phys)                    \
 264        __set_fixmap_offset(idx, phys, PAGE_KERNEL_NOCACHE)
 265
 266#endif /* !__ASSEMBLY__ */
 267#endif /* _ASM_X86_FIXMAP_H */
 268