1 #ifndef _ASM_POWERPC_PAGE_H 2 #define _ASM_POWERPC_PAGE_H 3 4 /* 5 * Copyright (C) 2001,2005 IBM Corporation. 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 */ 12 13 #ifndef __ASSEMBLY__ 14 #include <linux/types.h> 15 #include <linux/kernel.h> 16 #else 17 #include <asm/types.h> 18 #endif 19 #include <asm/asm-compat.h> 20 #include <asm/kdump.h> 21 22 /* 23 * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages 24 * on PPC44x). For PPC64 we support either 4K or 64K software 25 * page size. When using 64K pages however, whether we are really supporting 26 * 64K pages in HW or not is irrelevant to those definitions. 27 */ 28 #if defined(CONFIG_PPC_256K_PAGES) 29 #define PAGE_SHIFT 18 30 #elif defined(CONFIG_PPC_64K_PAGES) 31 #define PAGE_SHIFT 16 32 #elif defined(CONFIG_PPC_16K_PAGES) 33 #define PAGE_SHIFT 14 34 #else 35 #define PAGE_SHIFT 12 36 #endif 37 38 #define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT) 39 40 #ifndef __ASSEMBLY__ 41 #ifdef CONFIG_HUGETLB_PAGE 42 extern bool hugetlb_disabled; 43 extern unsigned int HPAGE_SHIFT; 44 #else 45 #define HPAGE_SHIFT PAGE_SHIFT 46 #endif 47 #define HPAGE_SIZE ((1UL) << HPAGE_SHIFT) 48 #define HPAGE_MASK (~(HPAGE_SIZE - 1)) 49 #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT) 50 #define HUGE_MAX_HSTATE (MMU_PAGE_COUNT-1) 51 #endif 52 53 /* 54 * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we 55 * assign PAGE_MASK to a larger type it gets extended the way we want 56 * (i.e. with 1s in the high bits) 57 */ 58 #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) 59 60 /* 61 * KERNELBASE is the virtual address of the start of the kernel, it's often 62 * the same as PAGE_OFFSET, but _might not be_. 63 * 64 * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET. 65 * 66 * PAGE_OFFSET is the virtual address of the start of lowmem. 67 * 68 * PHYSICAL_START is the physical address of the start of the kernel. 69 * 70 * MEMORY_START is the physical address of the start of lowmem. 71 * 72 * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on 73 * ppc32 and based on how they are set we determine MEMORY_START. 74 * 75 * For the linear mapping the following equation should be true: 76 * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START 77 * 78 * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START 79 * 80 * There are two ways to determine a physical address from a virtual one: 81 * va = pa + PAGE_OFFSET - MEMORY_START 82 * va = pa + KERNELBASE - PHYSICAL_START 83 * 84 * If you want to know something's offset from the start of the kernel you 85 * should subtract KERNELBASE. 86 * 87 * If you want to test if something's a kernel address, use is_kernel_addr(). 88 */ 89 90 #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START) 91 #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET) 92 #define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START)) 93 94 #if defined(CONFIG_NONSTATIC_KERNEL) 95 #ifndef __ASSEMBLY__ 96 97 extern phys_addr_t memstart_addr; 98 extern phys_addr_t kernstart_addr; 99 100 #if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC32) 101 extern long long virt_phys_offset; 102 #endif 103 104 #endif /* __ASSEMBLY__ */ 105 #define PHYSICAL_START kernstart_addr 106 107 #else /* !CONFIG_NONSTATIC_KERNEL */ 108 #define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START) 109 #endif 110 111 /* See Description below for VIRT_PHYS_OFFSET */ 112 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) 113 #ifdef CONFIG_RELOCATABLE 114 #define VIRT_PHYS_OFFSET virt_phys_offset 115 #else 116 #define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START) 117 #endif 118 #endif 119 120 #ifdef CONFIG_PPC64 121 #define MEMORY_START 0UL 122 #elif defined(CONFIG_NONSTATIC_KERNEL) 123 #define MEMORY_START memstart_addr 124 #else 125 #define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE) 126 #endif 127 128 #ifdef CONFIG_FLATMEM 129 #define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT)) 130 #ifndef __ASSEMBLY__ 131 extern unsigned long max_mapnr; 132 static inline bool pfn_valid(unsigned long pfn) 133 { 134 unsigned long min_pfn = ARCH_PFN_OFFSET; 135 136 return pfn >= min_pfn && pfn < max_mapnr; 137 } 138 #endif 139 #endif 140 141 #define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT) 142 #define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr)) 143 #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) 144 145 #ifdef CONFIG_PPC_BOOK3S_64 146 /* 147 * On hash the vmalloc and other regions alias to the kernel region when passed 148 * through __pa(), which virt_to_pfn() uses. That means virt_addr_valid() can 149 * return true for some vmalloc addresses, which is incorrect. So explicitly 150 * check that the address is in the kernel region. 151 */ 152 #define virt_addr_valid(kaddr) (REGION_ID(kaddr) == KERNEL_REGION_ID && \ 153 pfn_valid(virt_to_pfn(kaddr))) 154 #else 155 #define virt_addr_valid(kaddr) pfn_valid(virt_to_pfn(kaddr)) 156 #endif 157 158 /* 159 * On Book-E parts we need __va to parse the device tree and we can't 160 * determine MEMORY_START until then. However we can determine PHYSICAL_START 161 * from information at hand (program counter, TLB lookup). 162 * 163 * On BookE with RELOCATABLE && PPC32 164 * 165 * With RELOCATABLE && PPC32, we support loading the kernel at any physical 166 * address without any restriction on the page alignment. 167 * 168 * We find the runtime address of _stext and relocate ourselves based on 169 * the following calculation: 170 * 171 * virtual_base = ALIGN_DOWN(KERNELBASE,256M) + 172 * MODULO(_stext.run,256M) 173 * and create the following mapping: 174 * 175 * ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M) 176 * 177 * When we process relocations, we cannot depend on the 178 * existing equation for the __va()/__pa() translations: 179 * 180 * __va(x) = (x) - PHYSICAL_START + KERNELBASE 181 * 182 * Where: 183 * PHYSICAL_START = kernstart_addr = Physical address of _stext 184 * KERNELBASE = Compiled virtual address of _stext. 185 * 186 * This formula holds true iff, kernel load address is TLB page aligned. 187 * 188 * In our case, we need to also account for the shift in the kernel Virtual 189 * address. 190 * 191 * E.g., 192 * 193 * Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET). 194 * In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M 195 * 196 * Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000 197 * = 0xbc100000 , which is wrong. 198 * 199 * Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000 200 * according to our mapping. 201 * 202 * Hence we use the following formula to get the translations right: 203 * 204 * __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ] 205 * 206 * Where : 207 * PHYSICAL_START = dynamic load address.(kernstart_addr variable) 208 * Effective KERNELBASE = virtual_base = 209 * = ALIGN_DOWN(KERNELBASE,256M) + 210 * MODULO(PHYSICAL_START,256M) 211 * 212 * To make the cost of __va() / __pa() more light weight, we introduce 213 * a new variable virt_phys_offset, which will hold : 214 * 215 * virt_phys_offset = Effective KERNELBASE - PHYSICAL_START 216 * = ALIGN_DOWN(KERNELBASE,256M) - 217 * ALIGN_DOWN(PHYSICALSTART,256M) 218 * 219 * Hence : 220 * 221 * __va(x) = x - PHYSICAL_START + Effective KERNELBASE 222 * = x + virt_phys_offset 223 * 224 * and 225 * __pa(x) = x + PHYSICAL_START - Effective KERNELBASE 226 * = x - virt_phys_offset 227 * 228 * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use 229 * the other definitions for __va & __pa. 230 */ 231 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) 232 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET)) 233 #define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET) 234 #else 235 #ifdef CONFIG_PPC64 236 /* 237 * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET 238 * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit. 239 */ 240 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET)) 241 #define __pa(x) ((unsigned long)(x) & 0x0fffffffffffffffUL) 242 243 #else /* 32-bit, non book E */ 244 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START)) 245 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START) 246 #endif 247 #endif 248 249 /* 250 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI, 251 * and needs to be executable. This means the whole heap ends 252 * up being executable. 253 */ 254 #define VM_DATA_DEFAULT_FLAGS32 \ 255 (((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \ 256 VM_READ | VM_WRITE | \ 257 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) 258 259 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \ 260 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) 261 262 #ifdef __powerpc64__ 263 #include <asm/page_64.h> 264 #else 265 #include <asm/page_32.h> 266 #endif 267 268 /* align addr on a size boundary - adjust address up/down if needed */ 269 #define _ALIGN_UP(addr, size) __ALIGN_KERNEL(addr, size) 270 #define _ALIGN_DOWN(addr, size) ((addr)&(~((typeof(addr))(size)-1))) 271 272 /* align addr on a size boundary - adjust address up if needed */ 273 #define _ALIGN(addr,size) _ALIGN_UP(addr,size) 274 275 /* 276 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for 277 * "kernelness", use is_kernel_addr() - it should do what you want. 278 */ 279 #ifdef CONFIG_PPC_BOOK3E_64 280 #define is_kernel_addr(x) ((x) >= 0x8000000000000000ul) 281 #else 282 #define is_kernel_addr(x) ((x) >= PAGE_OFFSET) 283 #endif 284 285 #ifndef CONFIG_PPC_BOOK3S_64 286 /* 287 * Use the top bit of the higher-level page table entries to indicate whether 288 * the entries we point to contain hugepages. This works because we know that 289 * the page tables live in kernel space. If we ever decide to support having 290 * page tables at arbitrary addresses, this breaks and will have to change. 291 */ 292 #ifdef CONFIG_PPC64 293 #define PD_HUGE 0x8000000000000000 294 #else 295 #define PD_HUGE 0x80000000 296 #endif 297 298 #else /* CONFIG_PPC_BOOK3S_64 */ 299 /* 300 * Book3S 64 stores real addresses in the hugepd entries to 301 * avoid overlaps with _PAGE_PRESENT and _PAGE_PTE. 302 */ 303 #define HUGEPD_ADDR_MASK (0x0ffffffffffffffful & ~HUGEPD_SHIFT_MASK) 304 #endif /* CONFIG_PPC_BOOK3S_64 */ 305 306 /* 307 * Some number of bits at the level of the page table that points to 308 * a hugepte are used to encode the size. This masks those bits. 309 */ 310 #define HUGEPD_SHIFT_MASK 0x3f 311 312 #ifndef __ASSEMBLY__ 313 314 #ifdef CONFIG_PPC_BOOK3S_64 315 #include <asm/pgtable-be-types.h> 316 #else 317 #include <asm/pgtable-types.h> 318 #endif 319 320 321 #ifndef CONFIG_HUGETLB_PAGE 322 #define is_hugepd(pdep) (0) 323 #define pgd_huge(pgd) (0) 324 #endif /* CONFIG_HUGETLB_PAGE */ 325 326 struct page; 327 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg); 328 extern void copy_user_page(void *to, void *from, unsigned long vaddr, 329 struct page *p); 330 extern int page_is_ram(unsigned long pfn); 331 extern int devmem_is_allowed(unsigned long pfn); 332 333 #ifdef CONFIG_PPC_SMLPAR 334 void arch_free_page(struct page *page, int order); 335 #define HAVE_ARCH_FREE_PAGE 336 #endif 337 338 struct vm_area_struct; 339 #ifdef CONFIG_PPC_BOOK3S_64 340 /* 341 * For BOOK3s 64 with 4k and 64K linux page size 342 * we want to use pointers, because the page table 343 * actually store pfn 344 */ 345 typedef pte_t *pgtable_t; 346 #else 347 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC64) 348 typedef pte_t *pgtable_t; 349 #else 350 typedef struct page *pgtable_t; 351 #endif 352 #endif 353 354 #include <asm-generic/memory_model.h> 355 #endif /* __ASSEMBLY__ */ 356 #include <asm/slice.h> 357 358 #endif /* _ASM_POWERPC_PAGE_H */ 359