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