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 #define PAGE_SHIFT CONFIG_PPC_PAGE_SHIFT 25 #define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT) 26 27 #ifndef __ASSEMBLY__ 28 #ifndef CONFIG_HUGETLB_PAGE 29 #define HPAGE_SHIFT PAGE_SHIFT 30 #elif defined(CONFIG_PPC_BOOK3S_64) 31 extern unsigned int hpage_shift; 32 #define HPAGE_SHIFT hpage_shift 33 #elif defined(CONFIG_PPC_8xx) 34 #define HPAGE_SHIFT 19 /* 512k pages */ 35 #elif defined(CONFIG_PPC_E500) 36 #define HPAGE_SHIFT 22 /* 4M pages */ 37 #endif 38 #define HPAGE_SIZE ((1UL) << HPAGE_SHIFT) 39 #define HPAGE_MASK (~(HPAGE_SIZE - 1)) 40 #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT) 41 #define HUGE_MAX_HSTATE (MMU_PAGE_COUNT-1) 42 #endif 43 44 /* 45 * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we 46 * assign PAGE_MASK to a larger type it gets extended the way we want 47 * (i.e. with 1s in the high bits) 48 */ 49 #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) 50 51 /* 52 * KERNELBASE is the virtual address of the start of the kernel, it's often 53 * the same as PAGE_OFFSET, but _might not be_. 54 * 55 * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET. 56 * 57 * PAGE_OFFSET is the virtual address of the start of lowmem. 58 * 59 * PHYSICAL_START is the physical address of the start of the kernel. 60 * 61 * MEMORY_START is the physical address of the start of lowmem. 62 * 63 * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on 64 * ppc32 and based on how they are set we determine MEMORY_START. 65 * 66 * For the linear mapping the following equation should be true: 67 * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START 68 * 69 * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START 70 * 71 * There are two ways to determine a physical address from a virtual one: 72 * va = pa + PAGE_OFFSET - MEMORY_START 73 * va = pa + KERNELBASE - PHYSICAL_START 74 * 75 * If you want to know something's offset from the start of the kernel you 76 * should subtract KERNELBASE. 77 * 78 * If you want to test if something's a kernel address, use is_kernel_addr(). 79 */ 80 81 #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START) 82 #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET) 83 #define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START)) 84 85 #if defined(CONFIG_NONSTATIC_KERNEL) 86 #ifndef __ASSEMBLY__ 87 88 extern phys_addr_t memstart_addr; 89 extern phys_addr_t kernstart_addr; 90 91 #if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC32) 92 extern long long virt_phys_offset; 93 #endif 94 95 #endif /* __ASSEMBLY__ */ 96 #define PHYSICAL_START kernstart_addr 97 98 #else /* !CONFIG_NONSTATIC_KERNEL */ 99 #define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START) 100 #endif 101 102 /* See Description below for VIRT_PHYS_OFFSET */ 103 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) 104 #ifdef CONFIG_RELOCATABLE 105 #define VIRT_PHYS_OFFSET virt_phys_offset 106 #else 107 #define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START) 108 #endif 109 #endif 110 111 #ifdef CONFIG_PPC64 112 #define MEMORY_START 0UL 113 #elif defined(CONFIG_NONSTATIC_KERNEL) 114 #define MEMORY_START memstart_addr 115 #else 116 #define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE) 117 #endif 118 119 #ifdef CONFIG_FLATMEM 120 #define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT)) 121 #endif 122 123 /* 124 * On Book-E parts we need __va to parse the device tree and we can't 125 * determine MEMORY_START until then. However we can determine PHYSICAL_START 126 * from information at hand (program counter, TLB lookup). 127 * 128 * On BookE with RELOCATABLE && PPC32 129 * 130 * With RELOCATABLE && PPC32, we support loading the kernel at any physical 131 * address without any restriction on the page alignment. 132 * 133 * We find the runtime address of _stext and relocate ourselves based on 134 * the following calculation: 135 * 136 * virtual_base = ALIGN_DOWN(KERNELBASE,256M) + 137 * MODULO(_stext.run,256M) 138 * and create the following mapping: 139 * 140 * ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M) 141 * 142 * When we process relocations, we cannot depend on the 143 * existing equation for the __va()/__pa() translations: 144 * 145 * __va(x) = (x) - PHYSICAL_START + KERNELBASE 146 * 147 * Where: 148 * PHYSICAL_START = kernstart_addr = Physical address of _stext 149 * KERNELBASE = Compiled virtual address of _stext. 150 * 151 * This formula holds true iff, kernel load address is TLB page aligned. 152 * 153 * In our case, we need to also account for the shift in the kernel Virtual 154 * address. 155 * 156 * E.g., 157 * 158 * Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET). 159 * In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M 160 * 161 * Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000 162 * = 0xbc100000 , which is wrong. 163 * 164 * Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000 165 * according to our mapping. 166 * 167 * Hence we use the following formula to get the translations right: 168 * 169 * __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ] 170 * 171 * Where : 172 * PHYSICAL_START = dynamic load address.(kernstart_addr variable) 173 * Effective KERNELBASE = virtual_base = 174 * = ALIGN_DOWN(KERNELBASE,256M) + 175 * MODULO(PHYSICAL_START,256M) 176 * 177 * To make the cost of __va() / __pa() more light weight, we introduce 178 * a new variable virt_phys_offset, which will hold : 179 * 180 * virt_phys_offset = Effective KERNELBASE - PHYSICAL_START 181 * = ALIGN_DOWN(KERNELBASE,256M) - 182 * ALIGN_DOWN(PHYSICALSTART,256M) 183 * 184 * Hence : 185 * 186 * __va(x) = x - PHYSICAL_START + Effective KERNELBASE 187 * = x + virt_phys_offset 188 * 189 * and 190 * __pa(x) = x + PHYSICAL_START - Effective KERNELBASE 191 * = x - virt_phys_offset 192 * 193 * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use 194 * the other definitions for __va & __pa. 195 */ 196 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) 197 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET)) 198 #define __pa(x) ((phys_addr_t)(unsigned long)(x) - VIRT_PHYS_OFFSET) 199 #else 200 #ifdef CONFIG_PPC64 201 202 #define VIRTUAL_WARN_ON(x) WARN_ON(IS_ENABLED(CONFIG_DEBUG_VIRTUAL) && (x)) 203 204 /* 205 * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET 206 * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit. 207 * This also results in better code generation. 208 */ 209 #define __va(x) \ 210 ({ \ 211 VIRTUAL_WARN_ON((unsigned long)(x) >= PAGE_OFFSET); \ 212 (void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET); \ 213 }) 214 215 #define __pa(x) \ 216 ({ \ 217 VIRTUAL_WARN_ON((unsigned long)(x) < PAGE_OFFSET); \ 218 (unsigned long)(x) & 0x0fffffffffffffffUL; \ 219 }) 220 221 #else /* 32-bit, non book E */ 222 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START)) 223 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START) 224 #endif 225 #endif 226 227 #ifndef __ASSEMBLY__ 228 static inline unsigned long virt_to_pfn(const void *kaddr) 229 { 230 return __pa(kaddr) >> PAGE_SHIFT; 231 } 232 233 static inline const void *pfn_to_kaddr(unsigned long pfn) 234 { 235 return __va(pfn << PAGE_SHIFT); 236 } 237 #endif 238 239 #define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr)) 240 #define virt_addr_valid(vaddr) ({ \ 241 unsigned long _addr = (unsigned long)vaddr; \ 242 _addr >= PAGE_OFFSET && _addr < (unsigned long)high_memory && \ 243 pfn_valid(virt_to_pfn((void *)_addr)); \ 244 }) 245 246 /* 247 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI, 248 * and needs to be executable. This means the whole heap ends 249 * up being executable. 250 */ 251 #define VM_DATA_DEFAULT_FLAGS32 VM_DATA_FLAGS_TSK_EXEC 252 #define VM_DATA_DEFAULT_FLAGS64 VM_DATA_FLAGS_NON_EXEC 253 254 #ifdef __powerpc64__ 255 #include <asm/page_64.h> 256 #else 257 #include <asm/page_32.h> 258 #endif 259 260 /* 261 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for 262 * "kernelness", use is_kernel_addr() - it should do what you want. 263 */ 264 #ifdef CONFIG_PPC_BOOK3E_64 265 #define is_kernel_addr(x) ((x) >= 0x8000000000000000ul) 266 #elif defined(CONFIG_PPC_BOOK3S_64) 267 #define is_kernel_addr(x) ((x) >= PAGE_OFFSET) 268 #else 269 #define is_kernel_addr(x) ((x) >= TASK_SIZE) 270 #endif 271 272 #ifndef CONFIG_PPC_BOOK3S_64 273 /* 274 * Use the top bit of the higher-level page table entries to indicate whether 275 * the entries we point to contain hugepages. This works because we know that 276 * the page tables live in kernel space. If we ever decide to support having 277 * page tables at arbitrary addresses, this breaks and will have to change. 278 */ 279 #ifdef CONFIG_PPC64 280 #define PD_HUGE 0x8000000000000000UL 281 #else 282 #define PD_HUGE 0x80000000 283 #endif 284 285 #else /* CONFIG_PPC_BOOK3S_64 */ 286 /* 287 * Book3S 64 stores real addresses in the hugepd entries to 288 * avoid overlaps with _PAGE_PRESENT and _PAGE_PTE. 289 */ 290 #define HUGEPD_ADDR_MASK (0x0ffffffffffffffful & ~HUGEPD_SHIFT_MASK) 291 #endif /* CONFIG_PPC_BOOK3S_64 */ 292 293 /* 294 * Some number of bits at the level of the page table that points to 295 * a hugepte are used to encode the size. This masks those bits. 296 * On 8xx, HW assistance requires 4k alignment for the hugepte. 297 */ 298 #ifdef CONFIG_PPC_8xx 299 #define HUGEPD_SHIFT_MASK 0xfff 300 #else 301 #define HUGEPD_SHIFT_MASK 0x3f 302 #endif 303 304 #ifndef __ASSEMBLY__ 305 306 #ifdef CONFIG_PPC_BOOK3S_64 307 #include <asm/pgtable-be-types.h> 308 #else 309 #include <asm/pgtable-types.h> 310 #endif 311 312 struct page; 313 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg); 314 extern void copy_user_page(void *to, void *from, unsigned long vaddr, 315 struct page *p); 316 extern int devmem_is_allowed(unsigned long pfn); 317 318 #ifdef CONFIG_PPC_SMLPAR 319 void arch_free_page(struct page *page, int order); 320 #define HAVE_ARCH_FREE_PAGE 321 #endif 322 323 struct vm_area_struct; 324 325 extern unsigned long kernstart_virt_addr; 326 327 static inline unsigned long kaslr_offset(void) 328 { 329 return kernstart_virt_addr - KERNELBASE; 330 } 331 332 #include <asm-generic/memory_model.h> 333 #endif /* __ASSEMBLY__ */ 334 335 #endif /* _ASM_POWERPC_PAGE_H */ 336