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 42extern 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 96extern phys_addr_t memstart_addr; 97extern phys_addr_t kernstart_addr; 98 99#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC32) 100extern 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#ifndef __ASSEMBLY__ 130extern unsigned long max_mapnr; 131static inline bool pfn_valid(unsigned long pfn) 132{ 133 unsigned long min_pfn = ARCH_PFN_OFFSET; 134 135 return pfn >= min_pfn && pfn < max_mapnr; 136} 137#endif 138#endif 139 140#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT) 141#define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr)) 142#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) 143 144#ifdef CONFIG_PPC_BOOK3S_64 145/* 146 * On hash the vmalloc and other regions alias to the kernel region when passed 147 * through __pa(), which virt_to_pfn() uses. That means virt_addr_valid() can 148 * return true for some vmalloc addresses, which is incorrect. So explicitly 149 * check that the address is in the kernel region. 150 */ 151#define virt_addr_valid(kaddr) (REGION_ID(kaddr) == KERNEL_REGION_ID && \ 152 pfn_valid(virt_to_pfn(kaddr))) 153#else 154#define virt_addr_valid(kaddr) pfn_valid(virt_to_pfn(kaddr)) 155#endif 156 157/* 158 * On Book-E parts we need __va to parse the device tree and we can't 159 * determine MEMORY_START until then. However we can determine PHYSICAL_START 160 * from information at hand (program counter, TLB lookup). 161 * 162 * On BookE with RELOCATABLE && PPC32 163 * 164 * With RELOCATABLE && PPC32, we support loading the kernel at any physical 165 * address without any restriction on the page alignment. 166 * 167 * We find the runtime address of _stext and relocate ourselves based on 168 * the following calculation: 169 * 170 * virtual_base = ALIGN_DOWN(KERNELBASE,256M) + 171 * MODULO(_stext.run,256M) 172 * and create the following mapping: 173 * 174 * ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M) 175 * 176 * When we process relocations, we cannot depend on the 177 * existing equation for the __va()/__pa() translations: 178 * 179 * __va(x) = (x) - PHYSICAL_START + KERNELBASE 180 * 181 * Where: 182 * PHYSICAL_START = kernstart_addr = Physical address of _stext 183 * KERNELBASE = Compiled virtual address of _stext. 184 * 185 * This formula holds true iff, kernel load address is TLB page aligned. 186 * 187 * In our case, we need to also account for the shift in the kernel Virtual 188 * address. 189 * 190 * E.g., 191 * 192 * Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET). 193 * In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M 194 * 195 * Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000 196 * = 0xbc100000 , which is wrong. 197 * 198 * Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000 199 * according to our mapping. 200 * 201 * Hence we use the following formula to get the translations right: 202 * 203 * __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ] 204 * 205 * Where : 206 * PHYSICAL_START = dynamic load address.(kernstart_addr variable) 207 * Effective KERNELBASE = virtual_base = 208 * = ALIGN_DOWN(KERNELBASE,256M) + 209 * MODULO(PHYSICAL_START,256M) 210 * 211 * To make the cost of __va() / __pa() more light weight, we introduce 212 * a new variable virt_phys_offset, which will hold : 213 * 214 * virt_phys_offset = Effective KERNELBASE - PHYSICAL_START 215 * = ALIGN_DOWN(KERNELBASE,256M) - 216 * ALIGN_DOWN(PHYSICALSTART,256M) 217 * 218 * Hence : 219 * 220 * __va(x) = x - PHYSICAL_START + Effective KERNELBASE 221 * = x + virt_phys_offset 222 * 223 * and 224 * __pa(x) = x + PHYSICAL_START - Effective KERNELBASE 225 * = x - virt_phys_offset 226 * 227 * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use 228 * the other definitions for __va & __pa. 229 */ 230#if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) 231#define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET)) 232#define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET) 233#else 234#ifdef CONFIG_PPC64 235/* 236 * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET 237 * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit. 238 */ 239#define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET)) 240#define __pa(x) ((unsigned long)(x) & 0x0fffffffffffffffUL) 241 242#else /* 32-bit, non book E */ 243#define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START)) 244#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START) 245#endif 246#endif 247 248/* 249 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI, 250 * and needs to be executable. This means the whole heap ends 251 * up being executable. 252 */ 253#define VM_DATA_DEFAULT_FLAGS32 \ 254 (((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \ 255 VM_READ | VM_WRITE | \ 256 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) 257 258#define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \ 259 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) 260 261#ifdef __powerpc64__ 262#include <asm/page_64.h> 263#else 264#include <asm/page_32.h> 265#endif 266 267/* align addr on a size boundary - adjust address up/down if needed */ 268#define _ALIGN_UP(addr, size) __ALIGN_KERNEL(addr, size) 269#define _ALIGN_DOWN(addr, size) ((addr)&(~((typeof(addr))(size)-1))) 270 271/* align addr on a size boundary - adjust address up if needed */ 272#define _ALIGN(addr,size) _ALIGN_UP(addr,size) 273 274/* 275 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for 276 * "kernelness", use is_kernel_addr() - it should do what you want. 277 */ 278#ifdef CONFIG_PPC_BOOK3E_64 279#define is_kernel_addr(x) ((x) >= 0x8000000000000000ul) 280#else 281#define is_kernel_addr(x) ((x) >= PAGE_OFFSET) 282#endif 283 284#ifndef CONFIG_PPC_BOOK3S_64 285/* 286 * Use the top bit of the higher-level page table entries to indicate whether 287 * the entries we point to contain hugepages. This works because we know that 288 * the page tables live in kernel space. If we ever decide to support having 289 * page tables at arbitrary addresses, this breaks and will have to change. 290 */ 291#ifdef CONFIG_PPC64 292#define PD_HUGE 0x8000000000000000 293#else 294#define PD_HUGE 0x80000000 295#endif 296 297#else /* CONFIG_PPC_BOOK3S_64 */ 298/* 299 * Book3S 64 stores real addresses in the hugepd entries to 300 * avoid overlaps with _PAGE_PRESENT and _PAGE_PTE. 301 */ 302#define HUGEPD_ADDR_MASK (0x0ffffffffffffffful & ~HUGEPD_SHIFT_MASK) 303#endif /* CONFIG_PPC_BOOK3S_64 */ 304 305/* 306 * Some number of bits at the level of the page table that points to 307 * a hugepte are used to encode the size. This masks those bits. 308 */ 309#define HUGEPD_SHIFT_MASK 0x3f 310 311#ifndef __ASSEMBLY__ 312 313#ifdef CONFIG_PPC_BOOK3S_64 314#include <asm/pgtable-be-types.h> 315#else 316#include <asm/pgtable-types.h> 317#endif 318 319 320#ifndef CONFIG_HUGETLB_PAGE 321#define is_hugepd(pdep) (0) 322#define pgd_huge(pgd) (0) 323#endif /* CONFIG_HUGETLB_PAGE */ 324 325struct page; 326extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg); 327extern void copy_user_page(void *to, void *from, unsigned long vaddr, 328 struct page *p); 329extern int page_is_ram(unsigned long pfn); 330extern int devmem_is_allowed(unsigned long pfn); 331 332#ifdef CONFIG_PPC_SMLPAR 333void arch_free_page(struct page *page, int order); 334#define HAVE_ARCH_FREE_PAGE 335#endif 336 337struct vm_area_struct; 338#ifdef CONFIG_PPC_BOOK3S_64 339/* 340 * For BOOK3s 64 with 4k and 64K linux page size 341 * we want to use pointers, because the page table 342 * actually store pfn 343 */ 344typedef pte_t *pgtable_t; 345#else 346#if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC64) 347typedef pte_t *pgtable_t; 348#else 349typedef struct page *pgtable_t; 350#endif 351#endif 352 353#include <asm-generic/memory_model.h> 354#endif /* __ASSEMBLY__ */ 355#include <asm/slice.h> 356 357#endif /* _ASM_POWERPC_PAGE_H */ 358