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 */ 166