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 #else 13 #include <asm/types.h> 14 #endif 15 #include <asm/asm-const.h> 16 17 /* 18 * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages 19 * on PPC44x and 4K/16K on 8xx). For PPC64 we support either 4K or 64K software 20 * page size. When using 64K pages however, whether we are really supporting 21 * 64K pages in HW or not is irrelevant to those definitions. 22 */ 23 #define PAGE_SHIFT CONFIG_PPC_PAGE_SHIFT 24 #define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT) 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 * 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 #define virt_addr_valid(vaddr) ({ \ 136 unsigned long _addr = (unsigned long)vaddr; \ 137 _addr >= PAGE_OFFSET && _addr < (unsigned long)high_memory && \ 138 pfn_valid(virt_to_pfn(_addr)); \ 139 }) 140 141 /* 142 * On Book-E parts we need __va to parse the device tree and we can't 143 * determine MEMORY_START until then. However we can determine PHYSICAL_START 144 * from information at hand (program counter, TLB lookup). 145 * 146 * On BookE with RELOCATABLE && PPC32 147 * 148 * With RELOCATABLE && PPC32, we support loading the kernel at any physical 149 * address without any restriction on the page alignment. 150 * 151 * We find the runtime address of _stext and relocate ourselves based on 152 * the following calculation: 153 * 154 * virtual_base = ALIGN_DOWN(KERNELBASE,256M) + 155 * MODULO(_stext.run,256M) 156 * and create the following mapping: 157 * 158 * ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M) 159 * 160 * When we process relocations, we cannot depend on the 161 * existing equation for the __va()/__pa() translations: 162 * 163 * __va(x) = (x) - PHYSICAL_START + KERNELBASE 164 * 165 * Where: 166 * PHYSICAL_START = kernstart_addr = Physical address of _stext 167 * KERNELBASE = Compiled virtual address of _stext. 168 * 169 * This formula holds true iff, kernel load address is TLB page aligned. 170 * 171 * In our case, we need to also account for the shift in the kernel Virtual 172 * address. 173 * 174 * E.g., 175 * 176 * Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET). 177 * In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M 178 * 179 * Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000 180 * = 0xbc100000 , which is wrong. 181 * 182 * Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000 183 * according to our mapping. 184 * 185 * Hence we use the following formula to get the translations right: 186 * 187 * __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ] 188 * 189 * Where : 190 * PHYSICAL_START = dynamic load address.(kernstart_addr variable) 191 * Effective KERNELBASE = virtual_base = 192 * = ALIGN_DOWN(KERNELBASE,256M) + 193 * MODULO(PHYSICAL_START,256M) 194 * 195 * To make the cost of __va() / __pa() more light weight, we introduce 196 * a new variable virt_phys_offset, which will hold : 197 * 198 * virt_phys_offset = Effective KERNELBASE - PHYSICAL_START 199 * = ALIGN_DOWN(KERNELBASE,256M) - 200 * ALIGN_DOWN(PHYSICALSTART,256M) 201 * 202 * Hence : 203 * 204 * __va(x) = x - PHYSICAL_START + Effective KERNELBASE 205 * = x + virt_phys_offset 206 * 207 * and 208 * __pa(x) = x + PHYSICAL_START - Effective KERNELBASE 209 * = x - virt_phys_offset 210 * 211 * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use 212 * the other definitions for __va & __pa. 213 */ 214 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE) 215 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET)) 216 #define __pa(x) ((phys_addr_t)(unsigned long)(x) - VIRT_PHYS_OFFSET) 217 #else 218 #ifdef CONFIG_PPC64 219 220 #define VIRTUAL_WARN_ON(x) WARN_ON(IS_ENABLED(CONFIG_DEBUG_VIRTUAL) && (x)) 221 222 /* 223 * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET 224 * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit. 225 * This also results in better code generation. 226 */ 227 #define __va(x) \ 228 ({ \ 229 VIRTUAL_WARN_ON((unsigned long)(x) >= PAGE_OFFSET); \ 230 (void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET); \ 231 }) 232 233 #define __pa(x) \ 234 ({ \ 235 VIRTUAL_WARN_ON((unsigned long)(x) < PAGE_OFFSET); \ 236 (unsigned long)(x) & 0x0fffffffffffffffUL; \ 237 }) 238 239 #else /* 32-bit, non book E */ 240 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START)) 241 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START) 242 #endif 243 #endif 244 245 /* 246 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI, 247 * and needs to be executable. This means the whole heap ends 248 * up being executable. 249 */ 250 #define VM_DATA_DEFAULT_FLAGS32 VM_DATA_FLAGS_TSK_EXEC 251 #define VM_DATA_DEFAULT_FLAGS64 VM_DATA_FLAGS_NON_EXEC 252 253 #ifdef __powerpc64__ 254 #include <asm/page_64.h> 255 #else 256 #include <asm/page_32.h> 257 #endif 258 259 /* 260 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for 261 * "kernelness", use is_kernel_addr() - it should do what you want. 262 */ 263 #ifdef CONFIG_PPC_BOOK3E_64 264 #define is_kernel_addr(x) ((x) >= 0x8000000000000000ul) 265 #elif defined(CONFIG_PPC_BOOK3S_64) 266 #define is_kernel_addr(x) ((x) >= PAGE_OFFSET) 267 #else 268 #define is_kernel_addr(x) ((x) >= TASK_SIZE) 269 #endif 270 271 #ifndef CONFIG_PPC_BOOK3S_64 272 /* 273 * Use the top bit of the higher-level page table entries to indicate whether 274 * the entries we point to contain hugepages. This works because we know that 275 * the page tables live in kernel space. If we ever decide to support having 276 * page tables at arbitrary addresses, this breaks and will have to change. 277 */ 278 #ifdef CONFIG_PPC64 279 #define PD_HUGE 0x8000000000000000UL 280 #else 281 #define PD_HUGE 0x80000000 282 #endif 283 284 #else /* CONFIG_PPC_BOOK3S_64 */ 285 /* 286 * Book3S 64 stores real addresses in the hugepd entries to 287 * avoid overlaps with _PAGE_PRESENT and _PAGE_PTE. 288 */ 289 #define HUGEPD_ADDR_MASK (0x0ffffffffffffffful & ~HUGEPD_SHIFT_MASK) 290 #endif /* CONFIG_PPC_BOOK3S_64 */ 291 292 /* 293 * Some number of bits at the level of the page table that points to 294 * a hugepte are used to encode the size. This masks those bits. 295 * On 8xx, HW assistance requires 4k alignment for the hugepte. 296 */ 297 #ifdef CONFIG_PPC_8xx 298 #define HUGEPD_SHIFT_MASK 0xfff 299 #else 300 #define HUGEPD_SHIFT_MASK 0x3f 301 #endif 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 struct page; 312 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg); 313 extern void copy_user_page(void *to, void *from, unsigned long vaddr, 314 struct page *p); 315 extern int devmem_is_allowed(unsigned long pfn); 316 317 #ifdef CONFIG_PPC_SMLPAR 318 void arch_free_page(struct page *page, int order); 319 #define HAVE_ARCH_FREE_PAGE 320 #endif 321 322 struct vm_area_struct; 323 324 extern unsigned long kernstart_virt_addr; 325 326 static inline unsigned long kaslr_offset(void) 327 { 328 return kernstart_virt_addr - KERNELBASE; 329 } 330 331 #include <asm-generic/memory_model.h> 332 #endif /* __ASSEMBLY__ */ 333 334 #endif /* _ASM_POWERPC_PAGE_H */ 335