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 * cpu_entry_area is a percpu region in the fixmap that contains things 49 * needed by the CPU and early entry/exit code. Real types aren't used 50 * for all fields here to avoid circular header dependencies. 51 * 52 * Every field is a virtual alias of some other allocated backing store. 53 * There is no direct allocation of a struct cpu_entry_area. 54 */ 55 struct cpu_entry_area { 56 char gdt[PAGE_SIZE]; 57 58 /* 59 * The GDT is just below cpu_tss and thus serves (on x86_64) as a 60 * a read-only guard page for the SYSENTER stack at the bottom 61 * of the TSS region. 62 */ 63 struct tss_struct tss; 64 }; 65 66 #define CPU_ENTRY_AREA_PAGES (sizeof(struct cpu_entry_area) / PAGE_SIZE) 67 68 /* 69 * Here we define all the compile-time 'special' virtual 70 * addresses. The point is to have a constant address at 71 * compile time, but to set the physical address only 72 * in the boot process. 73 * for x86_32: We allocate these special addresses 74 * from the end of virtual memory (0xfffff000) backwards. 75 * Also this lets us do fail-safe vmalloc(), we 76 * can guarantee that these special addresses and 77 * vmalloc()-ed addresses never overlap. 78 * 79 * These 'compile-time allocated' memory buffers are 80 * fixed-size 4k pages (or larger if used with an increment 81 * higher than 1). Use set_fixmap(idx,phys) to associate 82 * physical memory with fixmap indices. 83 * 84 * TLB entries of such buffers will not be flushed across 85 * task switches. 86 */ 87 enum fixed_addresses { 88 #ifdef CONFIG_X86_32 89 FIX_HOLE, 90 #else 91 #ifdef CONFIG_X86_VSYSCALL_EMULATION 92 VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT, 93 #endif 94 #endif 95 FIX_DBGP_BASE, 96 FIX_EARLYCON_MEM_BASE, 97 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT 98 FIX_OHCI1394_BASE, 99 #endif 100 #ifdef CONFIG_X86_LOCAL_APIC 101 FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */ 102 #endif 103 #ifdef CONFIG_X86_IO_APIC 104 FIX_IO_APIC_BASE_0, 105 FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1, 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 /* Fixmap entries to remap the GDTs, one per processor. */ 124 FIX_CPU_ENTRY_AREA_TOP, 125 FIX_CPU_ENTRY_AREA_BOTTOM = FIX_CPU_ENTRY_AREA_TOP + (CPU_ENTRY_AREA_PAGES * NR_CPUS) - 1, 126 127 #ifdef CONFIG_ACPI_APEI_GHES 128 /* Used for GHES mapping from assorted contexts */ 129 FIX_APEI_GHES_IRQ, 130 FIX_APEI_GHES_NMI, 131 #endif 132 133 __end_of_permanent_fixed_addresses, 134 135 /* 136 * 512 temporary boot-time mappings, used by early_ioremap(), 137 * before ioremap() is functional. 138 * 139 * If necessary we round it up to the next 512 pages boundary so 140 * that we can have a single pgd entry and a single pte table: 141 */ 142 #define NR_FIX_BTMAPS 64 143 #define FIX_BTMAPS_SLOTS 8 144 #define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) 145 FIX_BTMAP_END = 146 (__end_of_permanent_fixed_addresses ^ 147 (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) & 148 -PTRS_PER_PTE 149 ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 150 (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1)) 151 : __end_of_permanent_fixed_addresses, 152 FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1, 153 #ifdef CONFIG_X86_32 154 FIX_WP_TEST, 155 #endif 156 #ifdef CONFIG_INTEL_TXT 157 FIX_TBOOT_BASE, 158 #endif 159 __end_of_fixed_addresses 160 }; 161 162 163 extern void reserve_top_address(unsigned long reserve); 164 165 #define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) 166 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) 167 168 extern int fixmaps_set; 169 170 extern pte_t *kmap_pte; 171 #define kmap_prot PAGE_KERNEL 172 extern pte_t *pkmap_page_table; 173 174 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte); 175 void native_set_fixmap(enum fixed_addresses idx, 176 phys_addr_t phys, pgprot_t flags); 177 178 #ifndef CONFIG_PARAVIRT 179 static inline void __set_fixmap(enum fixed_addresses idx, 180 phys_addr_t phys, pgprot_t flags) 181 { 182 native_set_fixmap(idx, phys, flags); 183 } 184 #endif 185 186 /* 187 * FIXMAP_PAGE_NOCACHE is used for MMIO. Memory encryption is not 188 * supported for MMIO addresses, so make sure that the memory encryption 189 * mask is not part of the page attributes. 190 */ 191 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE 192 193 /* 194 * Early memremap routines used for in-place encryption. The mappings created 195 * by these routines are intended to be used as temporary mappings. 196 */ 197 void __init *early_memremap_encrypted(resource_size_t phys_addr, 198 unsigned long size); 199 void __init *early_memremap_encrypted_wp(resource_size_t phys_addr, 200 unsigned long size); 201 void __init *early_memremap_decrypted(resource_size_t phys_addr, 202 unsigned long size); 203 void __init *early_memremap_decrypted_wp(resource_size_t phys_addr, 204 unsigned long size); 205 206 #include <asm-generic/fixmap.h> 207 208 #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags) 209 #define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0)) 210 211 void __early_set_fixmap(enum fixed_addresses idx, 212 phys_addr_t phys, pgprot_t flags); 213 214 static inline unsigned int __get_cpu_entry_area_page_index(int cpu, int page) 215 { 216 BUILD_BUG_ON(sizeof(struct cpu_entry_area) % PAGE_SIZE != 0); 217 218 return FIX_CPU_ENTRY_AREA_BOTTOM - cpu*CPU_ENTRY_AREA_PAGES - page; 219 } 220 221 #define __get_cpu_entry_area_offset_index(cpu, offset) ({ \ 222 BUILD_BUG_ON(offset % PAGE_SIZE != 0); \ 223 __get_cpu_entry_area_page_index(cpu, offset / PAGE_SIZE); \ 224 }) 225 226 #define get_cpu_entry_area_index(cpu, field) \ 227 __get_cpu_entry_area_offset_index((cpu), offsetof(struct cpu_entry_area, field)) 228 229 static inline struct cpu_entry_area *get_cpu_entry_area(int cpu) 230 { 231 return (struct cpu_entry_area *)__fix_to_virt(__get_cpu_entry_area_page_index(cpu, 0)); 232 } 233 234 #endif /* !__ASSEMBLY__ */ 235 #endif /* _ASM_X86_FIXMAP_H */ 236