1/* 2 * linux/arch/unicore32/include/asm/pgtable.h 3 * 4 * Code specific to PKUnity SoC and UniCore ISA 5 * 6 * Copyright (C) 2001-2010 GUAN Xue-tao 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12#ifndef __UNICORE_PGTABLE_H__ 13#define __UNICORE_PGTABLE_H__ 14 15#include <asm-generic/pgtable-nopmd.h> 16#include <asm/cpu-single.h> 17 18#include <asm/memory.h> 19#include <asm/pgtable-hwdef.h> 20 21/* 22 * Just any arbitrary offset to the start of the vmalloc VM area: the 23 * current 8MB value just means that there will be a 8MB "hole" after the 24 * physical memory until the kernel virtual memory starts. That means that 25 * any out-of-bounds memory accesses will hopefully be caught. 26 * The vmalloc() routines leaves a hole of 4kB between each vmalloced 27 * area for the same reason. ;) 28 * 29 * Note that platforms may override VMALLOC_START, but they must provide 30 * VMALLOC_END. VMALLOC_END defines the (exclusive) limit of this space, 31 * which may not overlap IO space. 32 */ 33#ifndef VMALLOC_START 34#define VMALLOC_OFFSET SZ_8M 35#define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) \ 36 & ~(VMALLOC_OFFSET-1)) 37#define VMALLOC_END (0xff000000UL) 38#endif 39 40#define PTRS_PER_PTE 1024 41#define PTRS_PER_PGD 1024 42 43/* 44 * PGDIR_SHIFT determines what a third-level page table entry can map 45 */ 46#define PGDIR_SHIFT 22 47 48#ifndef __ASSEMBLY__ 49extern void __pte_error(const char *file, int line, unsigned long val); 50extern void __pgd_error(const char *file, int line, unsigned long val); 51 52#define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte_val(pte)) 53#define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd)) 54#endif /* !__ASSEMBLY__ */ 55 56#define PGDIR_SIZE (1UL << PGDIR_SHIFT) 57#define PGDIR_MASK (~(PGDIR_SIZE-1)) 58 59/* 60 * This is the lowest virtual address we can permit any user space 61 * mapping to be mapped at. This is particularly important for 62 * non-high vector CPUs. 63 */ 64#define FIRST_USER_ADDRESS PAGE_SIZE 65 66#define FIRST_USER_PGD_NR 1 67#define USER_PTRS_PER_PGD ((TASK_SIZE/PGDIR_SIZE) - FIRST_USER_PGD_NR) 68 69/* 70 * section address mask and size definitions. 71 */ 72#define SECTION_SHIFT 22 73#define SECTION_SIZE (1UL << SECTION_SHIFT) 74#define SECTION_MASK (~(SECTION_SIZE-1)) 75 76#ifndef __ASSEMBLY__ 77 78/* 79 * The pgprot_* and protection_map entries will be fixed up in runtime 80 * to include the cachable bits based on memory policy, as well as any 81 * architecture dependent bits. 82 */ 83#define _PTE_DEFAULT (PTE_PRESENT | PTE_YOUNG | PTE_CACHEABLE) 84 85extern pgprot_t pgprot_user; 86extern pgprot_t pgprot_kernel; 87 88#define PAGE_NONE pgprot_user 89#define PAGE_SHARED __pgprot(pgprot_val(pgprot_user | PTE_READ \ 90 | PTE_WRITE)) 91#define PAGE_SHARED_EXEC __pgprot(pgprot_val(pgprot_user | PTE_READ \ 92 | PTE_WRITE \ 93 | PTE_EXEC)) 94#define PAGE_COPY __pgprot(pgprot_val(pgprot_user | PTE_READ) 95#define PAGE_COPY_EXEC __pgprot(pgprot_val(pgprot_user | PTE_READ \ 96 | PTE_EXEC)) 97#define PAGE_READONLY __pgprot(pgprot_val(pgprot_user | PTE_READ)) 98#define PAGE_READONLY_EXEC __pgprot(pgprot_val(pgprot_user | PTE_READ \ 99 | PTE_EXEC)) 100#define PAGE_KERNEL pgprot_kernel 101#define PAGE_KERNEL_EXEC __pgprot(pgprot_val(pgprot_kernel | PTE_EXEC)) 102 103#define __PAGE_NONE __pgprot(_PTE_DEFAULT) 104#define __PAGE_SHARED __pgprot(_PTE_DEFAULT | PTE_READ \ 105 | PTE_WRITE) 106#define __PAGE_SHARED_EXEC __pgprot(_PTE_DEFAULT | PTE_READ \ 107 | PTE_WRITE \ 108 | PTE_EXEC) 109#define __PAGE_COPY __pgprot(_PTE_DEFAULT | PTE_READ) 110#define __PAGE_COPY_EXEC __pgprot(_PTE_DEFAULT | PTE_READ \ 111 | PTE_EXEC) 112#define __PAGE_READONLY __pgprot(_PTE_DEFAULT | PTE_READ) 113#define __PAGE_READONLY_EXEC __pgprot(_PTE_DEFAULT | PTE_READ \ 114 | PTE_EXEC) 115 116#endif /* __ASSEMBLY__ */ 117 118/* 119 * The table below defines the page protection levels that we insert into our 120 * Linux page table version. These get translated into the best that the 121 * architecture can perform. Note that on UniCore hardware: 122 * 1) We cannot do execute protection 123 * 2) If we could do execute protection, then read is implied 124 * 3) write implies read permissions 125 */ 126#define __P000 __PAGE_NONE 127#define __P001 __PAGE_READONLY 128#define __P010 __PAGE_COPY 129#define __P011 __PAGE_COPY 130#define __P100 __PAGE_READONLY_EXEC 131#define __P101 __PAGE_READONLY_EXEC 132#define __P110 __PAGE_COPY_EXEC 133#define __P111 __PAGE_COPY_EXEC 134 135#define __S000 __PAGE_NONE 136#define __S001 __PAGE_READONLY 137#define __S010 __PAGE_SHARED 138#define __S011 __PAGE_SHARED 139#define __S100 __PAGE_READONLY_EXEC 140#define __S101 __PAGE_READONLY_EXEC 141#define __S110 __PAGE_SHARED_EXEC 142#define __S111 __PAGE_SHARED_EXEC 143 144#ifndef __ASSEMBLY__ 145/* 146 * ZERO_PAGE is a global shared page that is always zero: used 147 * for zero-mapped memory areas etc.. 148 */ 149extern struct page *empty_zero_page; 150#define ZERO_PAGE(vaddr) (empty_zero_page) 151 152#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT) 153#define pfn_pte(pfn, prot) (__pte(((pfn) << PAGE_SHIFT) \ 154 | pgprot_val(prot))) 155 156#define pte_none(pte) (!pte_val(pte)) 157#define pte_clear(mm, addr, ptep) set_pte(ptep, __pte(0)) 158#define pte_page(pte) (pfn_to_page(pte_pfn(pte))) 159#define pte_offset_kernel(dir, addr) (pmd_page_vaddr(*(dir)) \ 160 + __pte_index(addr)) 161 162#define pte_offset_map(dir, addr) (pmd_page_vaddr(*(dir)) \ 163 + __pte_index(addr)) 164#define pte_unmap(pte) do { } while (0) 165 166#define set_pte(ptep, pte) cpu_set_pte(ptep, pte) 167 168#define set_pte_at(mm, addr, ptep, pteval) \ 169 do { \ 170 set_pte(ptep, pteval); \ 171 } while (0) 172 173/* 174 * The following only work if pte_present() is true. 175 * Undefined behaviour if not.. 176 */ 177#define pte_present(pte) (pte_val(pte) & PTE_PRESENT) 178#define pte_write(pte) (pte_val(pte) & PTE_WRITE) 179#define pte_dirty(pte) (pte_val(pte) & PTE_DIRTY) 180#define pte_young(pte) (pte_val(pte) & PTE_YOUNG) 181#define pte_exec(pte) (pte_val(pte) & PTE_EXEC) 182#define pte_special(pte) (0) 183 184#define PTE_BIT_FUNC(fn, op) \ 185static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; } 186 187PTE_BIT_FUNC(wrprotect, &= ~PTE_WRITE); 188PTE_BIT_FUNC(mkwrite, |= PTE_WRITE); 189PTE_BIT_FUNC(mkclean, &= ~PTE_DIRTY); 190PTE_BIT_FUNC(mkdirty, |= PTE_DIRTY); 191PTE_BIT_FUNC(mkold, &= ~PTE_YOUNG); 192PTE_BIT_FUNC(mkyoung, |= PTE_YOUNG); 193 194static inline pte_t pte_mkspecial(pte_t pte) { return pte; } 195 196/* 197 * Mark the prot value as uncacheable. 198 */ 199#define pgprot_noncached(prot) \ 200 __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE) 201#define pgprot_writecombine(prot) \ 202 __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE) 203#define pgprot_dmacoherent(prot) \ 204 __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE) 205 206#define pmd_none(pmd) (!pmd_val(pmd)) 207#define pmd_present(pmd) (pmd_val(pmd) & PMD_PRESENT) 208#define pmd_bad(pmd) (((pmd_val(pmd) & \ 209 (PMD_PRESENT | PMD_TYPE_MASK)) \ 210 != (PMD_PRESENT | PMD_TYPE_TABLE))) 211 212#define set_pmd(pmdpd, pmdval) \ 213 do { \ 214 *(pmdpd) = pmdval; \ 215 } while (0) 216 217#define pmd_clear(pmdp) \ 218 do { \ 219 set_pmd(pmdp, __pmd(0));\ 220 clean_pmd_entry(pmdp); \ 221 } while (0) 222 223#define pmd_page_vaddr(pmd) ((pte_t *)__va(pmd_val(pmd) & PAGE_MASK)) 224#define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd))) 225 226/* 227 * Conversion functions: convert a page and protection to a page entry, 228 * and a page entry and page directory to the page they refer to. 229 */ 230#define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot) 231 232/* to find an entry in a page-table-directory */ 233#define pgd_index(addr) ((addr) >> PGDIR_SHIFT) 234 235#define pgd_offset(mm, addr) ((mm)->pgd+pgd_index(addr)) 236 237/* to find an entry in a kernel page-table-directory */ 238#define pgd_offset_k(addr) pgd_offset(&init_mm, addr) 239 240/* Find an entry in the third-level page table.. */ 241#define __pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 242 243static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 244{ 245 const unsigned long mask = PTE_EXEC | PTE_WRITE | PTE_READ; 246 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask); 247 return pte; 248} 249 250extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; 251 252/* 253 * Encode and decode a swap entry. Swap entries are stored in the Linux 254 * page tables as follows: 255 * 256 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 257 * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 258 * <--------------- offset --------------> <--- type --> 0 0 0 0 0 259 * 260 * This gives us up to 127 swap files and 32GB per swap file. Note that 261 * the offset field is always non-zero. 262 */ 263#define __SWP_TYPE_SHIFT 5 264#define __SWP_TYPE_BITS 7 265#define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1) 266#define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT) 267 268#define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) \ 269 & __SWP_TYPE_MASK) 270#define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT) 271#define __swp_entry(type, offset) ((swp_entry_t) { \ 272 ((type) << __SWP_TYPE_SHIFT) | \ 273 ((offset) << __SWP_OFFSET_SHIFT) }) 274 275#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 276#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) 277 278/* 279 * It is an error for the kernel to have more swap files than we can 280 * encode in the PTEs. This ensures that we know when MAX_SWAPFILES 281 * is increased beyond what we presently support. 282 */ 283#define MAX_SWAPFILES_CHECK() \ 284 BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) 285 286/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ 287/* FIXME: this is not correct */ 288#define kern_addr_valid(addr) (1) 289 290#include <asm-generic/pgtable.h> 291 292#define pgtable_cache_init() do { } while (0) 293 294#endif /* !__ASSEMBLY__ */ 295 296#endif /* __UNICORE_PGTABLE_H__ */ 297