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-const.h> 20 21 /* 22 * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages 23 * on PPC44x and 4K/16K on 8xx). 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 #define PAGE_SHIFT CONFIG_PPC_PAGE_SHIFT 28 #define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT) 29 30 #ifndef __ASSEMBLY__ 31 #ifdef CONFIG_HUGETLB_PAGE 32 extern bool hugetlb_disabled; 33 extern unsigned int HPAGE_SHIFT; 34 #else 35 #define HPAGE_SHIFT PAGE_SHIFT 36 #endif 37 #define HPAGE_SIZE ((1UL) << HPAGE_SHIFT) 38 #define HPAGE_MASK (~(HPAGE_SIZE - 1)) 39 #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT) 40 #define HUGE_MAX_HSTATE (MMU_PAGE_COUNT-1) 41 #endif 42 43 /* 44 * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we 45 * assign PAGE_MASK to a larger type it gets extended the way we want 46 * (i.e. with 1s in the high bits) 47 */ 48 #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) 49 50 /* 51 * KERNELBASE is the virtual address of the start of the kernel, it's often 52 * the same as PAGE_OFFSET, but _might not be_. 53 * 54 * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET. 55 * 56 * PAGE_OFFSET is the virtual address of the start of lowmem. 57 * 58 * PHYSICAL_START is the physical address of the start of the kernel. 59 * 60 * MEMORY_START is the physical address of the start of lowmem. 61 * 62 * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on 63 * ppc32 and based on how they are set we determine MEMORY_START. 64 * 65 * For the linear mapping the following equation should be true: 66 * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START 67 * 68 * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START 69 * 70 * There are two ways to determine a physical address from a virtual one: 71 * va = pa + PAGE_OFFSET - MEMORY_START 72 * va = pa + KERNELBASE - PHYSICAL_START 73 * 74 * If you want to know something's offset from the start of the kernel you 75 * should subtract KERNELBASE. 76 * 77 * If you want to test if something's a kernel address, use is_kernel_addr(). 78 */ 79 80 #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START) 81 #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET) 82 #define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START)) 83 84 #if defined(CONFIG_NONSTATIC_KERNEL) 85 #ifndef __ASSEMBLY__ 86 87 extern phys_addr_t memstart_addr; 88 extern phys_addr_t kernstart_addr; 89 90 #if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC32) 91 extern long long virt_phys_offset; 92 #endif 93 94 #endif /* __ASSEMBLY__ */ 95 #define PHYSICAL_START kernstart_addr 96 97 #else /* !CONFIG_NONSTATIC_KERNEL */ 98 #define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START) 99 #endif 100 101 /* See Description below for VIRT_PHYS_OFFSET */ 102 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) 103 #ifdef CONFIG_RELOCATABLE 104 #define VIRT_PHYS_OFFSET virt_phys_offset 105 #else 106 #define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START) 107 #endif 108 #endif 109 110 #ifdef CONFIG_PPC64 111 #define MEMORY_START 0UL 112 #elif defined(CONFIG_NONSTATIC_KERNEL) 113 #define MEMORY_START memstart_addr 114 #else 115 #define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE) 116 #endif 117 118 #ifdef CONFIG_FLATMEM 119 #define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT)) 120 #ifndef __ASSEMBLY__ 121 extern unsigned long max_mapnr; 122 static inline bool pfn_valid(unsigned long pfn) 123 { 124 unsigned long min_pfn = ARCH_PFN_OFFSET; 125 126 return pfn >= min_pfn && pfn < max_mapnr; 127 } 128 #endif 129 #endif 130 131 #define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT) 132 #define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr)) 133 #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) 134 135 #ifdef CONFIG_PPC_BOOK3S_64 136 /* 137 * On hash the vmalloc and other regions alias to the kernel region when passed 138 * through __pa(), which virt_to_pfn() uses. That means virt_addr_valid() can 139 * return true for some vmalloc addresses, which is incorrect. So explicitly 140 * check that the address is in the kernel region. 141 */ 142 #define virt_addr_valid(kaddr) (REGION_ID(kaddr) == KERNEL_REGION_ID && \ 143 pfn_valid(virt_to_pfn(kaddr))) 144 #else 145 #define virt_addr_valid(kaddr) pfn_valid(virt_to_pfn(kaddr)) 146 #endif 147 148 /* 149 * On Book-E parts we need __va to parse the device tree and we can't 150 * determine MEMORY_START until then. However we can determine PHYSICAL_START 151 * from information at hand (program counter, TLB lookup). 152 * 153 * On BookE with RELOCATABLE && PPC32 154 * 155 * With RELOCATABLE && PPC32, we support loading the kernel at any physical 156 * address without any restriction on the page alignment. 157 * 158 * We find the runtime address of _stext and relocate ourselves based on 159 * the following calculation: 160 * 161 * virtual_base = ALIGN_DOWN(KERNELBASE,256M) + 162 * MODULO(_stext.run,256M) 163 * and create the following mapping: 164 * 165 * ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M) 166 * 167 * When we process relocations, we cannot depend on the 168 * existing equation for the __va()/__pa() translations: 169 * 170 * __va(x) = (x) - PHYSICAL_START + KERNELBASE 171 * 172 * Where: 173 * PHYSICAL_START = kernstart_addr = Physical address of _stext 174 * KERNELBASE = Compiled virtual address of _stext. 175 * 176 * This formula holds true iff, kernel load address is TLB page aligned. 177 * 178 * In our case, we need to also account for the shift in the kernel Virtual 179 * address. 180 * 181 * E.g., 182 * 183 * Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET). 184 * In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M 185 * 186 * Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000 187 * = 0xbc100000 , which is wrong. 188 * 189 * Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000 190 * according to our mapping. 191 * 192 * Hence we use the following formula to get the translations right: 193 * 194 * __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ] 195 * 196 * Where : 197 * PHYSICAL_START = dynamic load address.(kernstart_addr variable) 198 * Effective KERNELBASE = virtual_base = 199 * = ALIGN_DOWN(KERNELBASE,256M) + 200 * MODULO(PHYSICAL_START,256M) 201 * 202 * To make the cost of __va() / __pa() more light weight, we introduce 203 * a new variable virt_phys_offset, which will hold : 204 * 205 * virt_phys_offset = Effective KERNELBASE - PHYSICAL_START 206 * = ALIGN_DOWN(KERNELBASE,256M) - 207 * ALIGN_DOWN(PHYSICALSTART,256M) 208 * 209 * Hence : 210 * 211 * __va(x) = x - PHYSICAL_START + Effective KERNELBASE 212 * = x + virt_phys_offset 213 * 214 * and 215 * __pa(x) = x + PHYSICAL_START - Effective KERNELBASE 216 * = x - virt_phys_offset 217 * 218 * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use 219 * the other definitions for __va & __pa. 220 */ 221 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) 222 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET)) 223 #define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET) 224 #else 225 #ifdef CONFIG_PPC64 226 /* 227 * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET 228 * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit. 229 */ 230 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET)) 231 #define __pa(x) ((unsigned long)(x) & 0x0fffffffffffffffUL) 232 233 #else /* 32-bit, non book E */ 234 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START)) 235 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START) 236 #endif 237 #endif 238 239 /* 240 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI, 241 * and needs to be executable. This means the whole heap ends 242 * up being executable. 243 */ 244 #define VM_DATA_DEFAULT_FLAGS32 \ 245 (((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \ 246 VM_READ | VM_WRITE | \ 247 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) 248 249 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \ 250 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) 251 252 #ifdef __powerpc64__ 253 #include <asm/page_64.h> 254 #else 255 #include <asm/page_32.h> 256 #endif 257 258 /* align addr on a size boundary - adjust address up/down if needed */ 259 #define _ALIGN_UP(addr, size) __ALIGN_KERNEL(addr, size) 260 #define _ALIGN_DOWN(addr, size) ((addr)&(~((typeof(addr))(size)-1))) 261 262 /* align addr on a size boundary - adjust address up if needed */ 263 #define _ALIGN(addr,size) _ALIGN_UP(addr,size) 264 265 /* 266 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for 267 * "kernelness", use is_kernel_addr() - it should do what you want. 268 */ 269 #ifdef CONFIG_PPC_BOOK3E_64 270 #define is_kernel_addr(x) ((x) >= 0x8000000000000000ul) 271 #else 272 #define is_kernel_addr(x) ((x) >= PAGE_OFFSET) 273 #endif 274 275 #ifndef CONFIG_PPC_BOOK3S_64 276 /* 277 * Use the top bit of the higher-level page table entries to indicate whether 278 * the entries we point to contain hugepages. This works because we know that 279 * the page tables live in kernel space. If we ever decide to support having 280 * page tables at arbitrary addresses, this breaks and will have to change. 281 */ 282 #ifdef CONFIG_PPC64 283 #define PD_HUGE 0x8000000000000000UL 284 #else 285 #define PD_HUGE 0x80000000 286 #endif 287 288 #else /* CONFIG_PPC_BOOK3S_64 */ 289 /* 290 * Book3S 64 stores real addresses in the hugepd entries to 291 * avoid overlaps with _PAGE_PRESENT and _PAGE_PTE. 292 */ 293 #define HUGEPD_ADDR_MASK (0x0ffffffffffffffful & ~HUGEPD_SHIFT_MASK) 294 #endif /* CONFIG_PPC_BOOK3S_64 */ 295 296 /* 297 * Some number of bits at the level of the page table that points to 298 * a hugepte are used to encode the size. This masks those bits. 299 */ 300 #define HUGEPD_SHIFT_MASK 0x3f 301 302 #ifndef __ASSEMBLY__ 303 304 #ifdef CONFIG_PPC_BOOK3S_64 305 #include <asm/pgtable-be-types.h> 306 #else 307 #include <asm/pgtable-types.h> 308 #endif 309 310 311 #ifndef CONFIG_HUGETLB_PAGE 312 #define is_hugepd(pdep) (0) 313 #define pgd_huge(pgd) (0) 314 #endif /* CONFIG_HUGETLB_PAGE */ 315 316 struct page; 317 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg); 318 extern void copy_user_page(void *to, void *from, unsigned long vaddr, 319 struct page *p); 320 extern int devmem_is_allowed(unsigned long pfn); 321 322 #ifdef CONFIG_PPC_SMLPAR 323 void arch_free_page(struct page *page, int order); 324 #define HAVE_ARCH_FREE_PAGE 325 #endif 326 327 struct vm_area_struct; 328 329 #include <asm-generic/memory_model.h> 330 #endif /* __ASSEMBLY__ */ 331 #include <asm/slice.h> 332 333 #define ARCH_ZONE_DMA_BITS 31 334 335 #endif /* _ASM_POWERPC_PAGE_H */ 336