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 */ 12 13 #ifndef _ASM_FIXMAP_H 14 #define _ASM_FIXMAP_H 15 16 17 /* used by vmalloc.c, vsyscall.lds.S. 18 * 19 * Leave one empty page between vmalloc'ed areas and 20 * the start of the fixmap. 21 */ 22 extern unsigned long __FIXADDR_TOP; 23 #define FIXADDR_USER_START __fix_to_virt(FIX_VDSO) 24 #define FIXADDR_USER_END __fix_to_virt(FIX_VDSO - 1) 25 26 #ifndef __ASSEMBLY__ 27 #include <linux/kernel.h> 28 #include <asm/acpi.h> 29 #include <asm/apicdef.h> 30 #include <asm/page.h> 31 #ifdef CONFIG_HIGHMEM 32 #include <linux/threads.h> 33 #include <asm/kmap_types.h> 34 #endif 35 36 /* 37 * Here we define all the compile-time 'special' virtual 38 * addresses. The point is to have a constant address at 39 * compile time, but to set the physical address only 40 * in the boot process. We allocate these special addresses 41 * from the end of virtual memory (0xfffff000) backwards. 42 * Also this lets us do fail-safe vmalloc(), we 43 * can guarantee that these special addresses and 44 * vmalloc()-ed addresses never overlap. 45 * 46 * these 'compile-time allocated' memory buffers are 47 * fixed-size 4k pages. (or larger if used with an increment 48 * highger than 1) use fixmap_set(idx,phys) to associate 49 * physical memory with fixmap indices. 50 * 51 * TLB entries of such buffers will not be flushed across 52 * task switches. 53 */ 54 enum fixed_addresses { 55 FIX_HOLE, 56 FIX_VDSO, 57 FIX_DBGP_BASE, 58 FIX_EARLYCON_MEM_BASE, 59 #ifdef CONFIG_X86_LOCAL_APIC 60 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */ 61 #endif 62 #ifdef CONFIG_X86_IO_APIC 63 FIX_IO_APIC_BASE_0, 64 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS-1, 65 #endif 66 #ifdef CONFIG_X86_VISWS_APIC 67 FIX_CO_CPU, /* Cobalt timer */ 68 FIX_CO_APIC, /* Cobalt APIC Redirection Table */ 69 FIX_LI_PCIA, /* Lithium PCI Bridge A */ 70 FIX_LI_PCIB, /* Lithium PCI Bridge B */ 71 #endif 72 #ifdef CONFIG_X86_F00F_BUG 73 FIX_F00F_IDT, /* Virtual mapping for IDT */ 74 #endif 75 #ifdef CONFIG_X86_CYCLONE_TIMER 76 FIX_CYCLONE_TIMER, /*cyclone timer register*/ 77 #endif 78 #ifdef CONFIG_HIGHMEM 79 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ 80 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, 81 #endif 82 #ifdef CONFIG_ACPI 83 FIX_ACPI_BEGIN, 84 FIX_ACPI_END = FIX_ACPI_BEGIN + FIX_ACPI_PAGES - 1, 85 #endif 86 #ifdef CONFIG_PCI_MMCONFIG 87 FIX_PCIE_MCFG, 88 #endif 89 #ifdef CONFIG_PARAVIRT 90 FIX_PARAVIRT_BOOTMAP, 91 #endif 92 __end_of_permanent_fixed_addresses, 93 /* temporary boot-time mappings, used before ioremap() is functional */ 94 #define NR_FIX_BTMAPS 16 95 FIX_BTMAP_END = __end_of_permanent_fixed_addresses, 96 FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS - 1, 97 FIX_WP_TEST, 98 __end_of_fixed_addresses 99 }; 100 101 extern void __set_fixmap (enum fixed_addresses idx, 102 unsigned long phys, pgprot_t flags); 103 extern void reserve_top_address(unsigned long reserve); 104 105 #define set_fixmap(idx, phys) \ 106 __set_fixmap(idx, phys, PAGE_KERNEL) 107 /* 108 * Some hardware wants to get fixmapped without caching. 109 */ 110 #define set_fixmap_nocache(idx, phys) \ 111 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) 112 113 #define clear_fixmap(idx) \ 114 __set_fixmap(idx, 0, __pgprot(0)) 115 116 #define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP) 117 118 #define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) 119 #define __FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) 120 #define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE) 121 #define FIXADDR_BOOT_START (FIXADDR_TOP - __FIXADDR_BOOT_SIZE) 122 123 #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) 124 #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) 125 126 extern void __this_fixmap_does_not_exist(void); 127 128 /* 129 * 'index to address' translation. If anyone tries to use the idx 130 * directly without tranlation, we catch the bug with a NULL-deference 131 * kernel oops. Illegal ranges of incoming indices are caught too. 132 */ 133 static __always_inline unsigned long fix_to_virt(const unsigned int idx) 134 { 135 /* 136 * this branch gets completely eliminated after inlining, 137 * except when someone tries to use fixaddr indices in an 138 * illegal way. (such as mixing up address types or using 139 * out-of-range indices). 140 * 141 * If it doesn't get removed, the linker will complain 142 * loudly with a reasonably clear error message.. 143 */ 144 if (idx >= __end_of_fixed_addresses) 145 __this_fixmap_does_not_exist(); 146 147 return __fix_to_virt(idx); 148 } 149 150 static inline unsigned long virt_to_fix(const unsigned long vaddr) 151 { 152 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); 153 return __virt_to_fix(vaddr); 154 } 155 156 #endif /* !__ASSEMBLY__ */ 157 #endif 158
