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