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 #else 16 #include <asm/types.h> 17 #endif 18 #include <asm/asm-compat.h> 19 #include <asm/kdump.h> 20 21 /* 22 * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages 23 * on PPC44x). For PPC64 we support either 4K or 64K software 24 * page size. When using 64K pages however, whether we are really supporting 25 * 64K pages in HW or not is irrelevant to those definitions. 26 */ 27 #if defined(CONFIG_PPC_256K_PAGES) 28 #define PAGE_SHIFT 18 29 #elif defined(CONFIG_PPC_64K_PAGES) 30 #define PAGE_SHIFT 16 31 #elif defined(CONFIG_PPC_16K_PAGES) 32 #define PAGE_SHIFT 14 33 #else 34 #define PAGE_SHIFT 12 35 #endif 36 37 #define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT) 38 39 #ifndef __ASSEMBLY__ 40 #ifdef CONFIG_HUGETLB_PAGE 41 extern unsigned int HPAGE_SHIFT; 42 #else 43 #define HPAGE_SHIFT PAGE_SHIFT 44 #endif 45 #define HPAGE_SIZE ((1UL) << HPAGE_SHIFT) 46 #define HPAGE_MASK (~(HPAGE_SIZE - 1)) 47 #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT) 48 #define HUGE_MAX_HSTATE (MMU_PAGE_COUNT-1) 49 #endif 50 51 /* 52 * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we 53 * assign PAGE_MASK to a larger type it gets extended the way we want 54 * (i.e. with 1s in the high bits) 55 */ 56 #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) 57 58 /* 59 * KERNELBASE is the virtual address of the start of the kernel, it's often 60 * the same as PAGE_OFFSET, but _might not be_. 61 * 62 * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET. 63 * 64 * PAGE_OFFSET is the virtual address of the start of lowmem. 65 * 66 * PHYSICAL_START is the physical address of the start of the kernel. 67 * 68 * MEMORY_START is the physical address of the start of lowmem. 69 * 70 * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on 71 * ppc32 and based on how they are set we determine MEMORY_START. 72 * 73 * For the linear mapping the following equation should be true: 74 * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START 75 * 76 * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START 77 * 78 * There are two ways to determine a physical address from a virtual one: 79 * va = pa + PAGE_OFFSET - MEMORY_START 80 * va = pa + KERNELBASE - PHYSICAL_START 81 * 82 * If you want to know something's offset from the start of the kernel you 83 * should subtract KERNELBASE. 84 * 85 * If you want to test if something's a kernel address, use is_kernel_addr(). 86 */ 87 88 #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START) 89 #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET) 90 #define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START)) 91 92 #if defined(CONFIG_NONSTATIC_KERNEL) 93 #ifndef __ASSEMBLY__ 94 95 extern phys_addr_t memstart_addr; 96 extern phys_addr_t kernstart_addr; 97 98 #ifdef CONFIG_RELOCATABLE_PPC32 99 extern long long virt_phys_offset; 100 #endif 101 102 #endif /* __ASSEMBLY__ */ 103 #define PHYSICAL_START kernstart_addr 104 105 #else /* !CONFIG_NONSTATIC_KERNEL */ 106 #define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START) 107 #endif 108 109 /* See Description below for VIRT_PHYS_OFFSET */ 110 #ifdef CONFIG_RELOCATABLE_PPC32 111 #define VIRT_PHYS_OFFSET virt_phys_offset 112 #else 113 #define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START) 114 #endif 115 116 117 #ifdef CONFIG_PPC64 118 #define MEMORY_START 0UL 119 #elif defined(CONFIG_NONSTATIC_KERNEL) 120 #define MEMORY_START memstart_addr 121 #else 122 #define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE) 123 #endif 124 125 #ifdef CONFIG_FLATMEM 126 #define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT)) 127 #define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr) 128 #endif 129 130 #define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT) 131 #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) 132 #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) 133 134 /* 135 * On Book-E parts we need __va to parse the device tree and we can't 136 * determine MEMORY_START until then. However we can determine PHYSICAL_START 137 * from information at hand (program counter, TLB lookup). 138 * 139 * On BookE with RELOCATABLE (RELOCATABLE_PPC32) 140 * 141 * With RELOCATABLE_PPC32, we support loading the kernel at any physical 142 * address without any restriction on the page alignment. 143 * 144 * We find the runtime address of _stext and relocate ourselves based on 145 * the following calculation: 146 * 147 * virtual_base = ALIGN_DOWN(KERNELBASE,256M) + 148 * MODULO(_stext.run,256M) 149 * and create the following mapping: 150 * 151 * ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M) 152 * 153 * When we process relocations, we cannot depend on the 154 * existing equation for the __va()/__pa() translations: 155 * 156 * __va(x) = (x) - PHYSICAL_START + KERNELBASE 157 * 158 * Where: 159 * PHYSICAL_START = kernstart_addr = Physical address of _stext 160 * KERNELBASE = Compiled virtual address of _stext. 161 * 162 * This formula holds true iff, kernel load address is TLB page aligned. 163 * 164 * In our case, we need to also account for the shift in the kernel Virtual 165 * address. 166 * 167 * E.g., 168 * 169 * Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET). 170 * In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M 171 * 172 * Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000 173 * = 0xbc100000 , which is wrong. 174 * 175 * Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000 176 * according to our mapping. 177 * 178 * Hence we use the following formula to get the translations right: 179 * 180 * __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ] 181 * 182 * Where : 183 * PHYSICAL_START = dynamic load address.(kernstart_addr variable) 184 * Effective KERNELBASE = virtual_base = 185 * = ALIGN_DOWN(KERNELBASE,256M) + 186 * MODULO(PHYSICAL_START,256M) 187 * 188 * To make the cost of __va() / __pa() more light weight, we introduce 189 * a new variable virt_phys_offset, which will hold : 190 * 191 * virt_phys_offset = Effective KERNELBASE - PHYSICAL_START 192 * = ALIGN_DOWN(KERNELBASE,256M) - 193 * ALIGN_DOWN(PHYSICALSTART,256M) 194 * 195 * Hence : 196 * 197 * __va(x) = x - PHYSICAL_START + Effective KERNELBASE 198 * = x + virt_phys_offset 199 * 200 * and 201 * __pa(x) = x + PHYSICAL_START - Effective KERNELBASE 202 * = x - virt_phys_offset 203 * 204 * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use 205 * the other definitions for __va & __pa. 206 */ 207 #ifdef CONFIG_BOOKE 208 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET)) 209 #define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET) 210 #else 211 #ifdef CONFIG_PPC64 212 /* 213 * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET 214 * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit. 215 */ 216 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET)) 217 #define __pa(x) ((unsigned long)(x) & 0x0fffffffffffffffUL) 218 219 #else /* 32-bit, non book E */ 220 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START)) 221 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START) 222 #endif 223 #endif 224 225 /* 226 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI, 227 * and needs to be executable. This means the whole heap ends 228 * up being executable. 229 */ 230 #define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \ 231 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) 232 233 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \ 234 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) 235 236 #ifdef __powerpc64__ 237 #include <asm/page_64.h> 238 #else 239 #include <asm/page_32.h> 240 #endif 241 242 /* align addr on a size boundary - adjust address up/down if needed */ 243 #define _ALIGN_UP(addr,size) (((addr)+((size)-1))&(~((size)-1))) 244 #define _ALIGN_DOWN(addr,size) ((addr)&(~((size)-1))) 245 246 /* align addr on a size boundary - adjust address up if needed */ 247 #define _ALIGN(addr,size) _ALIGN_UP(addr,size) 248 249 /* 250 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for 251 * "kernelness", use is_kernel_addr() - it should do what you want. 252 */ 253 #ifdef CONFIG_PPC_BOOK3E_64 254 #define is_kernel_addr(x) ((x) >= 0x8000000000000000ul) 255 #else 256 #define is_kernel_addr(x) ((x) >= PAGE_OFFSET) 257 #endif 258 259 #ifndef CONFIG_PPC_BOOK3S_64 260 /* 261 * Use the top bit of the higher-level page table entries to indicate whether 262 * the entries we point to contain hugepages. This works because we know that 263 * the page tables live in kernel space. If we ever decide to support having 264 * page tables at arbitrary addresses, this breaks and will have to change. 265 */ 266 #ifdef CONFIG_PPC64 267 #define PD_HUGE 0x8000000000000000 268 #else 269 #define PD_HUGE 0x80000000 270 #endif 271 #endif /* CONFIG_PPC_BOOK3S_64 */ 272 273 /* 274 * Some number of bits at the level of the page table that points to 275 * a hugepte are used to encode the size. This masks those bits. 276 */ 277 #define HUGEPD_SHIFT_MASK 0x3f 278 279 #ifndef __ASSEMBLY__ 280 281 #undef STRICT_MM_TYPECHECKS 282 283 #ifdef STRICT_MM_TYPECHECKS 284 /* These are used to make use of C type-checking. */ 285 286 /* PTE level */ 287 typedef struct { pte_basic_t pte; } pte_t; 288 #define pte_val(x) ((x).pte) 289 #define __pte(x) ((pte_t) { (x) }) 290 291 /* 64k pages additionally define a bigger "real PTE" type that gathers 292 * the "second half" part of the PTE for pseudo 64k pages 293 */ 294 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64) 295 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t; 296 #else 297 typedef struct { pte_t pte; } real_pte_t; 298 #endif 299 300 /* PMD level */ 301 #ifdef CONFIG_PPC64 302 typedef struct { unsigned long pmd; } pmd_t; 303 #define pmd_val(x) ((x).pmd) 304 #define __pmd(x) ((pmd_t) { (x) }) 305 306 /* PUD level exusts only on 4k pages */ 307 #ifndef CONFIG_PPC_64K_PAGES 308 typedef struct { unsigned long pud; } pud_t; 309 #define pud_val(x) ((x).pud) 310 #define __pud(x) ((pud_t) { (x) }) 311 #endif /* !CONFIG_PPC_64K_PAGES */ 312 #endif /* CONFIG_PPC64 */ 313 314 /* PGD level */ 315 typedef struct { unsigned long pgd; } pgd_t; 316 #define pgd_val(x) ((x).pgd) 317 #define __pgd(x) ((pgd_t) { (x) }) 318 319 /* Page protection bits */ 320 typedef struct { unsigned long pgprot; } pgprot_t; 321 #define pgprot_val(x) ((x).pgprot) 322 #define __pgprot(x) ((pgprot_t) { (x) }) 323 324 #else 325 326 /* 327 * .. while these make it easier on the compiler 328 */ 329 330 typedef pte_basic_t pte_t; 331 #define pte_val(x) (x) 332 #define __pte(x) (x) 333 334 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64) 335 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t; 336 #else 337 typedef pte_t real_pte_t; 338 #endif 339 340 341 #ifdef CONFIG_PPC64 342 typedef unsigned long pmd_t; 343 #define pmd_val(x) (x) 344 #define __pmd(x) (x) 345 346 #ifndef CONFIG_PPC_64K_PAGES 347 typedef unsigned long pud_t; 348 #define pud_val(x) (x) 349 #define __pud(x) (x) 350 #endif /* !CONFIG_PPC_64K_PAGES */ 351 #endif /* CONFIG_PPC64 */ 352 353 typedef unsigned long pgd_t; 354 #define pgd_val(x) (x) 355 #define pgprot_val(x) (x) 356 357 typedef unsigned long pgprot_t; 358 #define __pgd(x) (x) 359 #define __pgprot(x) (x) 360 361 #endif 362 363 typedef struct { signed long pd; } hugepd_t; 364 365 #ifdef CONFIG_HUGETLB_PAGE 366 #ifdef CONFIG_PPC_BOOK3S_64 367 static inline int hugepd_ok(hugepd_t hpd) 368 { 369 /* 370 * hugepd pointer, bottom two bits == 00 and next 4 bits 371 * indicate size of table 372 */ 373 return (((hpd.pd & 0x3) == 0x0) && ((hpd.pd & HUGEPD_SHIFT_MASK) != 0)); 374 } 375 #else 376 static inline int hugepd_ok(hugepd_t hpd) 377 { 378 return (hpd.pd > 0); 379 } 380 #endif 381 382 #define is_hugepd(hpd) (hugepd_ok(hpd)) 383 #define pgd_huge pgd_huge 384 int pgd_huge(pgd_t pgd); 385 #else /* CONFIG_HUGETLB_PAGE */ 386 #define is_hugepd(pdep) 0 387 #define pgd_huge(pgd) 0 388 #endif /* CONFIG_HUGETLB_PAGE */ 389 #define __hugepd(x) ((hugepd_t) { (x) }) 390 391 struct page; 392 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg); 393 extern void copy_user_page(void *to, void *from, unsigned long vaddr, 394 struct page *p); 395 extern int page_is_ram(unsigned long pfn); 396 extern int devmem_is_allowed(unsigned long pfn); 397 398 #ifdef CONFIG_PPC_SMLPAR 399 void arch_free_page(struct page *page, int order); 400 #define HAVE_ARCH_FREE_PAGE 401 #endif 402 403 struct vm_area_struct; 404 405 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC64) 406 typedef pte_t *pgtable_t; 407 #else 408 typedef struct page *pgtable_t; 409 #endif 410 411 #include <asm-generic/memory_model.h> 412 #endif /* __ASSEMBLY__ */ 413 414 #endif /* _ASM_POWERPC_PAGE_H */ 415