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  */
  41 extern 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  */
  74 enum 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 #ifdef CONFIG_PARAVIRT_CLOCK
  85         PVCLOCK_FIXMAP_BEGIN,
  86         PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1,
  87 #endif
  88 #endif
  89         FIX_DBGP_BASE,
  90         FIX_EARLYCON_MEM_BASE,
  91 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
  92         FIX_OHCI1394_BASE,
  93 #endif
  94 #ifdef CONFIG_X86_LOCAL_APIC
  95         FIX_APIC_BASE,  /* local (CPU) APIC) -- required for SMP or not */
  96 #endif
  97 #ifdef CONFIG_X86_IO_APIC
  98         FIX_IO_APIC_BASE_0,
  99         FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
 100 #endif
 101 #ifdef CONFIG_X86_VISWS_APIC
 102         FIX_CO_CPU,     /* Cobalt timer */
 103         FIX_CO_APIC,    /* Cobalt APIC Redirection Table */
 104         FIX_LI_PCIA,    /* Lithium PCI Bridge A */
 105         FIX_LI_PCIB,    /* Lithium PCI Bridge B */
 106 #endif
 107         FIX_RO_IDT,     /* Virtual mapping for read-only IDT */
 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
 153 extern 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
 160 extern int fixmaps_set;
 161
 162 extern pte_t *kmap_pte;
 163 extern pgprot_t kmap_prot;
 164 extern pte_t *pkmap_page_table;
 165
 166 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
 167 void native_set_fixmap(enum fixed_addresses idx,
 168                        phys_addr_t phys, pgprot_t flags);
 169
 170 #ifndef CONFIG_PARAVIRT
 171 static 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
 193 extern 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  */
 200 static __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
 217 static 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 */
 224 static __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 */