1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 #ifndef _ASM_POWERPC_PAGE_H 3 #define _ASM_POWERPC_PAGE_H 4 5 /* 6 * Copyright (C) 2001,2005 IBM Corporation. 7 */ 8 9 #ifndef __ASSEMBLY__ 10 #include <linux/types.h> 11 #include <linux/kernel.h> 12 #include <linux/bug.h> 13 #else 14 #include <asm/types.h> 15 #endif 16 #include <asm/asm-const.h> 17 18 /* 19 * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages 20 * on PPC44x and 4K/16K on 8xx). For PPC64 we support either 4K or 64K software 21 * page size. When using 64K pages however, whether we are really supporting 22 * 64K pages in HW or not is irrelevant to those definitions. 23 */ 24 #include <vdso/page.h> 25 26 #ifndef __ASSEMBLY__ 27 #ifndef CONFIG_HUGETLB_PAGE 28 #define HPAGE_SHIFT PAGE_SHIFT 29 #elif defined(CONFIG_PPC_BOOK3S_64) 30 extern unsigned int hpage_shift; 31 #define HPAGE_SHIFT hpage_shift 32 #elif defined(CONFIG_PPC_8xx) 33 #define HPAGE_SHIFT 19 /* 512k pages */ 34 #elif defined(CONFIG_PPC_E500) 35 #define HPAGE_SHIFT 22 /* 4M pages */ 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 * KERNELBASE is the virtual address of the start of the kernel, it's often 45 * the same as PAGE_OFFSET, but _might not be_. 46 * 47 * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET. 48 * 49 * PAGE_OFFSET is the virtual address of the start of lowmem. 50 * 51 * PHYSICAL_START is the physical address of the start of the kernel. 52 * 53 * MEMORY_START is the physical address of the start of lowmem. 54 * 55 * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on 56 * ppc32 and based on how they are set we determine MEMORY_START. 57 * 58 * For the linear mapping the following equation should be true: 59 * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START 60 * 61 * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START 62 * 63 * There are two ways to determine a physical address from a virtual one: 64 * va = pa + PAGE_OFFSET - MEMORY_START 65 * va = pa + KERNELBASE - PHYSICAL_START 66 * 67 * If you want to know something's offset from the start of the kernel you 68 * should subtract KERNELBASE. 69 * 70 * If you want to test if something's a kernel address, use is_kernel_addr(). 71 */ 72 73 #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START) 74 #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET) 75 #define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START)) 76 77 #if defined(CONFIG_NONSTATIC_KERNEL) 78 #ifndef __ASSEMBLY__ 79 80 extern phys_addr_t memstart_addr; 81 extern phys_addr_t kernstart_addr; 82 83 #if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC32) 84 extern long long virt_phys_offset; 85 #endif 86 87 #endif /* __ASSEMBLY__ */ 88 #define PHYSICAL_START kernstart_addr 89 90 #else /* !CONFIG_NONSTATIC_KERNEL */ 91 #define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START) 92 #endif 93 94 /* See Description below for VIRT_PHYS_OFFSET */ 95 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) 96 #ifdef CONFIG_RELOCATABLE 97 #define VIRT_PHYS_OFFSET virt_phys_offset 98 #else 99 #define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START) 100 #endif 101 #endif 102 103 #ifdef CONFIG_PPC64 104 #define MEMORY_START 0UL 105 #elif defined(CONFIG_NONSTATIC_KERNEL) 106 #define MEMORY_START memstart_addr 107 #else 108 #define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE) 109 #endif 110 111 #ifdef CONFIG_FLATMEM 112 #define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT)) 113 #endif 114 115 /* 116 * On Book-E parts we need __va to parse the device tree and we can't 117 * determine MEMORY_START until then. However we can determine PHYSICAL_START 118 * from information at hand (program counter, TLB lookup). 119 * 120 * On BookE with RELOCATABLE && PPC32 121 * 122 * With RELOCATABLE && PPC32, we support loading the kernel at any physical 123 * address without any restriction on the page alignment. 124 * 125 * We find the runtime address of _stext and relocate ourselves based on 126 * the following calculation: 127 * 128 * virtual_base = ALIGN_DOWN(KERNELBASE,256M) + 129 * MODULO(_stext.run,256M) 130 * and create the following mapping: 131 * 132 * ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M) 133 * 134 * When we process relocations, we cannot depend on the 135 * existing equation for the __va()/__pa() translations: 136 * 137 * __va(x) = (x) - PHYSICAL_START + KERNELBASE 138 * 139 * Where: 140 * PHYSICAL_START = kernstart_addr = Physical address of _stext 141 * KERNELBASE = Compiled virtual address of _stext. 142 * 143 * This formula holds true iff, kernel load address is TLB page aligned. 144 * 145 * In our case, we need to also account for the shift in the kernel Virtual 146 * address. 147 * 148 * E.g., 149 * 150 * Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET). 151 * In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M 152 * 153 * Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000 154 * = 0xbc100000 , which is wrong. 155 * 156 * Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000 157 * according to our mapping. 158 * 159 * Hence we use the following formula to get the translations right: 160 * 161 * __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ] 162 * 163 * Where : 164 * PHYSICAL_START = dynamic load address.(kernstart_addr variable) 165 * Effective KERNELBASE = virtual_base = 166 * = ALIGN_DOWN(KERNELBASE,256M) + 167 * MODULO(PHYSICAL_START,256M) 168 * 169 * To make the cost of __va() / __pa() more light weight, we introduce 170 * a new variable virt_phys_offset, which will hold : 171 * 172 * virt_phys_offset = Effective KERNELBASE - PHYSICAL_START 173 * = ALIGN_DOWN(KERNELBASE,256M) - 174 * ALIGN_DOWN(PHYSICALSTART,256M) 175 * 176 * Hence : 177 * 178 * __va(x) = x - PHYSICAL_START + Effective KERNELBASE 179 * = x + virt_phys_offset 180 * 181 * and 182 * __pa(x) = x + PHYSICAL_START - Effective KERNELBASE 183 * = x - virt_phys_offset 184 * 185 * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use 186 * the other definitions for __va & __pa. 187 */ 188 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) 189 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET)) 190 #define __pa(x) ((phys_addr_t)(unsigned long)(x) - VIRT_PHYS_OFFSET) 191 #else 192 #ifdef CONFIG_PPC64 193 194 #define VIRTUAL_WARN_ON(x) WARN_ON(IS_ENABLED(CONFIG_DEBUG_VIRTUAL) && (x)) 195 196 /* 197 * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET 198 * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit. 199 * This also results in better code generation. 200 */ 201 #define __va(x) \ 202 ({ \ 203 VIRTUAL_WARN_ON((unsigned long)(x) >= PAGE_OFFSET); \ 204 (void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET); \ 205 }) 206 207 #define __pa(x) \ 208 ({ \ 209 VIRTUAL_WARN_ON((unsigned long)(x) < PAGE_OFFSET); \ 210 (unsigned long)(x) & 0x0fffffffffffffffUL; \ 211 }) 212 213 #else /* 32-bit, non book E */ 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 #endif 218 219 #ifndef __ASSEMBLY__ 220 static inline unsigned long virt_to_pfn(const void *kaddr) 221 { 222 return __pa(kaddr) >> PAGE_SHIFT; 223 } 224 225 static inline const void *pfn_to_kaddr(unsigned long pfn) 226 { 227 return __va(pfn << PAGE_SHIFT); 228 } 229 #endif 230 231 #define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr)) 232 #define virt_addr_valid(vaddr) ({ \ 233 unsigned long _addr = (unsigned long)vaddr; \ 234 _addr >= PAGE_OFFSET && _addr < (unsigned long)high_memory && \ 235 pfn_valid(virt_to_pfn((void *)_addr)); \ 236 }) 237 238 /* 239 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI, 240 * and needs to be executable. This means the whole heap ends 241 * up being executable. 242 */ 243 #define VM_DATA_DEFAULT_FLAGS32 VM_DATA_FLAGS_TSK_EXEC 244 #define VM_DATA_DEFAULT_FLAGS64 VM_DATA_FLAGS_NON_EXEC 245 246 #ifdef __powerpc64__ 247 #include <asm/page_64.h> 248 #else 249 #include <asm/page_32.h> 250 #endif 251 252 /* 253 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for 254 * "kernelness", use is_kernel_addr() - it should do what you want. 255 */ 256 #ifdef CONFIG_PPC_BOOK3E_64 257 #define is_kernel_addr(x) ((x) >= 0x8000000000000000ul) 258 #elif defined(CONFIG_PPC_BOOK3S_64) 259 #define is_kernel_addr(x) ((x) >= PAGE_OFFSET) 260 #else 261 #define is_kernel_addr(x) ((x) >= TASK_SIZE) 262 #endif 263 264 #ifndef __ASSEMBLY__ 265 266 #ifdef CONFIG_PPC_BOOK3S_64 267 #include <asm/pgtable-be-types.h> 268 #else 269 #include <asm/pgtable-types.h> 270 #endif 271 272 struct page; 273 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg); 274 extern void copy_user_page(void *to, void *from, unsigned long vaddr, 275 struct page *p); 276 extern int devmem_is_allowed(unsigned long pfn); 277 278 #ifdef CONFIG_PPC_SMLPAR 279 void arch_free_page(struct page *page, int order); 280 #define HAVE_ARCH_FREE_PAGE 281 #endif 282 283 struct vm_area_struct; 284 285 extern unsigned long kernstart_virt_addr; 286 287 static inline unsigned long kaslr_offset(void) 288 { 289 return kernstart_virt_addr - KERNELBASE; 290 } 291 292 #include <asm-generic/memory_model.h> 293 #endif /* __ASSEMBLY__ */ 294 295 #endif /* _ASM_POWERPC_PAGE_H */ 296