1/* MN10300 Page table manipulators and constants 2 * 3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public Licence 8 * as published by the Free Software Foundation; either version 9 * 2 of the Licence, or (at your option) any later version. 10 * 11 * 12 * The Linux memory management assumes a three-level page table setup. On 13 * the i386, we use that, but "fold" the mid level into the top-level page 14 * table, so that we physically have the same two-level page table as the 15 * i386 mmu expects. 16 * 17 * This file contains the functions and defines necessary to modify and use 18 * the i386 page table tree for the purposes of the MN10300 TLB handler 19 * functions. 20 */ 21#ifndef _ASM_PGTABLE_H 22#define _ASM_PGTABLE_H 23 24#include <asm/cpu-regs.h> 25 26#ifndef __ASSEMBLY__ 27#include <asm/processor.h> 28#include <asm/cache.h> 29#include <linux/threads.h> 30 31#include <asm/bitops.h> 32 33#include <linux/slab.h> 34#include <linux/list.h> 35#include <linux/spinlock.h> 36 37/* 38 * ZERO_PAGE is a global shared page that is always zero: used 39 * for zero-mapped memory areas etc.. 40 */ 41#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) 42extern unsigned long empty_zero_page[1024]; 43extern spinlock_t pgd_lock; 44extern struct page *pgd_list; 45 46extern void pmd_ctor(void *, struct kmem_cache *, unsigned long); 47extern void pgtable_cache_init(void); 48extern void paging_init(void); 49 50#endif /* !__ASSEMBLY__ */ 51 52/* 53 * The Linux mn10300 paging architecture only implements both the traditional 54 * 2-level page tables 55 */ 56#define PGDIR_SHIFT 22 57#define PTRS_PER_PGD 1024 58#define PTRS_PER_PUD 1 /* we don't really have any PUD physically */ 59#define PTRS_PER_PMD 1 /* we don't really have any PMD physically */ 60#define PTRS_PER_PTE 1024 61 62#define PGD_SIZE PAGE_SIZE 63#define PMD_SIZE (1UL << PMD_SHIFT) 64#define PGDIR_SIZE (1UL << PGDIR_SHIFT) 65#define PGDIR_MASK (~(PGDIR_SIZE - 1)) 66 67#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) 68#define FIRST_USER_ADDRESS 0 69 70#define USER_PGD_PTRS (PAGE_OFFSET >> PGDIR_SHIFT) 71#define KERNEL_PGD_PTRS (PTRS_PER_PGD - USER_PGD_PTRS) 72 73#define TWOLEVEL_PGDIR_SHIFT 22 74#define BOOT_USER_PGD_PTRS (__PAGE_OFFSET >> TWOLEVEL_PGDIR_SHIFT) 75#define BOOT_KERNEL_PGD_PTRS (1024 - BOOT_USER_PGD_PTRS) 76 77#ifndef __ASSEMBLY__ 78extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; 79#endif 80 81/* 82 * Unfortunately, due to the way the MMU works on the MN10300, the vmalloc VM 83 * area has to be in the lower half of the virtual address range (the upper 84 * half is not translated through the TLB). 85 * 86 * So in this case, the vmalloc area goes at the bottom of the address map 87 * (leaving a hole at the very bottom to catch addressing errors), and 88 * userspace starts immediately above. 89 * 90 * The vmalloc() routines also leaves a hole of 4kB between each vmalloced 91 * area to catch addressing errors. 92 */ 93#define VMALLOC_OFFSET (8 * 1024 * 1024) 94#define VMALLOC_START (0x70000000) 95#define VMALLOC_END (0x7C000000) 96 97#ifndef __ASSEMBLY__ 98extern pte_t kernel_vmalloc_ptes[(VMALLOC_END - VMALLOC_START) / PAGE_SIZE]; 99#endif 100 101/* IPTEL/DPTEL bit assignments */ 102#define _PAGE_BIT_VALID xPTEL_V_BIT 103#define _PAGE_BIT_ACCESSED xPTEL_UNUSED1_BIT /* mustn't be loaded into IPTEL/DPTEL */ 104#define _PAGE_BIT_NX xPTEL_UNUSED2_BIT /* mustn't be loaded into IPTEL/DPTEL */ 105#define _PAGE_BIT_CACHE xPTEL_C_BIT 106#define _PAGE_BIT_PRESENT xPTEL_PV_BIT 107#define _PAGE_BIT_DIRTY xPTEL_D_BIT 108#define _PAGE_BIT_GLOBAL xPTEL_G_BIT 109 110#define _PAGE_VALID xPTEL_V 111#define _PAGE_ACCESSED xPTEL_UNUSED1 112#define _PAGE_NX xPTEL_UNUSED2 /* no-execute bit */ 113#define _PAGE_CACHE xPTEL_C 114#define _PAGE_PRESENT xPTEL_PV 115#define _PAGE_DIRTY xPTEL_D 116#define _PAGE_PROT xPTEL_PR 117#define _PAGE_PROT_RKNU xPTEL_PR_ROK 118#define _PAGE_PROT_WKNU xPTEL_PR_RWK 119#define _PAGE_PROT_RKRU xPTEL_PR_ROK_ROU 120#define _PAGE_PROT_WKRU xPTEL_PR_RWK_ROU 121#define _PAGE_PROT_WKWU xPTEL_PR_RWK_RWU 122#define _PAGE_GLOBAL xPTEL_G 123#define _PAGE_PSE xPTEL_PS_4Mb /* 4MB page */ 124 125#define _PAGE_FILE xPTEL_UNUSED1_BIT /* set:pagecache unset:swap */ 126 127#define __PAGE_PROT_UWAUX 0x040 128#define __PAGE_PROT_USER 0x080 129#define __PAGE_PROT_WRITE 0x100 130 131#define _PAGE_PRESENTV (_PAGE_PRESENT|_PAGE_VALID) 132#define _PAGE_PROTNONE 0x000 /* If not present */ 133 134#ifndef __ASSEMBLY__ 135 136#define VMALLOC_VMADDR(x) ((unsigned long)(x)) 137 138#define _PAGE_TABLE (_PAGE_PRESENTV | _PAGE_PROT_WKNU | _PAGE_ACCESSED | _PAGE_DIRTY) 139#define _PAGE_CHG_MASK (PTE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY) 140 141#define __PAGE_NONE (_PAGE_PRESENTV | _PAGE_PROT_RKNU | _PAGE_ACCESSED | _PAGE_CACHE) 142#define __PAGE_SHARED (_PAGE_PRESENTV | _PAGE_PROT_WKWU | _PAGE_ACCESSED | _PAGE_CACHE) 143#define __PAGE_COPY (_PAGE_PRESENTV | _PAGE_PROT_RKRU | _PAGE_ACCESSED | _PAGE_CACHE) 144#define __PAGE_READONLY (_PAGE_PRESENTV | _PAGE_PROT_RKRU | _PAGE_ACCESSED | _PAGE_CACHE) 145 146#define PAGE_NONE __pgprot(__PAGE_NONE | _PAGE_NX) 147#define PAGE_SHARED_NOEXEC __pgprot(__PAGE_SHARED | _PAGE_NX) 148#define PAGE_COPY_NOEXEC __pgprot(__PAGE_COPY | _PAGE_NX) 149#define PAGE_READONLY_NOEXEC __pgprot(__PAGE_READONLY | _PAGE_NX) 150#define PAGE_SHARED_EXEC __pgprot(__PAGE_SHARED) 151#define PAGE_COPY_EXEC __pgprot(__PAGE_COPY) 152#define PAGE_READONLY_EXEC __pgprot(__PAGE_READONLY) 153#define PAGE_COPY PAGE_COPY_NOEXEC 154#define PAGE_READONLY PAGE_READONLY_NOEXEC 155#define PAGE_SHARED PAGE_SHARED_EXEC 156 157#define __PAGE_KERNEL_BASE (_PAGE_PRESENTV | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_GLOBAL) 158 159#define __PAGE_KERNEL (__PAGE_KERNEL_BASE | _PAGE_PROT_WKNU | _PAGE_CACHE | _PAGE_NX) 160#define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL_BASE | _PAGE_PROT_WKNU | _PAGE_NX) 161#define __PAGE_KERNEL_EXEC (__PAGE_KERNEL & ~_PAGE_NX) 162#define __PAGE_KERNEL_RO (__PAGE_KERNEL_BASE | _PAGE_PROT_RKNU | _PAGE_CACHE | _PAGE_NX) 163#define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE) 164#define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE) 165 166#define PAGE_KERNEL __pgprot(__PAGE_KERNEL) 167#define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO) 168#define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC) 169#define PAGE_KERNEL_NOCACHE __pgprot(__PAGE_KERNEL_NOCACHE) 170#define PAGE_KERNEL_LARGE __pgprot(__PAGE_KERNEL_LARGE) 171#define PAGE_KERNEL_LARGE_EXEC __pgprot(__PAGE_KERNEL_LARGE_EXEC) 172 173/* 174 * Whilst the MN10300 can do page protection for execute (given separate data 175 * and insn TLBs), we are not supporting it at the moment. Write permission, 176 * however, always implies read permission (but not execute permission). 177 */ 178#define __P000 PAGE_NONE 179#define __P001 PAGE_READONLY_NOEXEC 180#define __P010 PAGE_COPY_NOEXEC 181#define __P011 PAGE_COPY_NOEXEC 182#define __P100 PAGE_READONLY_EXEC 183#define __P101 PAGE_READONLY_EXEC 184#define __P110 PAGE_COPY_EXEC 185#define __P111 PAGE_COPY_EXEC 186 187#define __S000 PAGE_NONE 188#define __S001 PAGE_READONLY_NOEXEC 189#define __S010 PAGE_SHARED_NOEXEC 190#define __S011 PAGE_SHARED_NOEXEC 191#define __S100 PAGE_READONLY_EXEC 192#define __S101 PAGE_READONLY_EXEC 193#define __S110 PAGE_SHARED_EXEC 194#define __S111 PAGE_SHARED_EXEC 195 196/* 197 * Define this to warn about kernel memory accesses that are 198 * done without a 'verify_area(VERIFY_WRITE,..)' 199 */ 200#undef TEST_VERIFY_AREA 201 202#define pte_present(x) (pte_val(x) & _PAGE_VALID) 203#define pte_clear(mm, addr, xp) \ 204do { \ 205 set_pte_at((mm), (addr), (xp), __pte(0)); \ 206} while (0) 207 208#define pmd_none(x) (!pmd_val(x)) 209#define pmd_present(x) (!pmd_none(x)) 210#define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0) 211#define pmd_bad(x) 0 212 213 214#define pages_to_mb(x) ((x) >> (20 - PAGE_SHIFT)) 215 216#ifndef __ASSEMBLY__ 217 218/* 219 * The following only work if pte_present() is true. 220 * Undefined behaviour if not.. 221 */ 222static inline int pte_user(pte_t pte) { return pte_val(pte) & __PAGE_PROT_USER; } 223static inline int pte_read(pte_t pte) { return pte_val(pte) & __PAGE_PROT_USER; } 224static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; } 225static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; } 226static inline int pte_write(pte_t pte) { return pte_val(pte) & __PAGE_PROT_WRITE; } 227static inline int pte_special(pte_t pte){ return 0; } 228 229/* 230 * The following only works if pte_present() is not true. 231 */ 232static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; } 233 234static inline pte_t pte_rdprotect(pte_t pte) 235{ 236 pte_val(pte) &= ~(__PAGE_PROT_USER|__PAGE_PROT_UWAUX); return pte; 237} 238static inline pte_t pte_exprotect(pte_t pte) 239{ 240 pte_val(pte) |= _PAGE_NX; return pte; 241} 242 243static inline pte_t pte_wrprotect(pte_t pte) 244{ 245 pte_val(pte) &= ~(__PAGE_PROT_WRITE|__PAGE_PROT_UWAUX); return pte; 246} 247 248static inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~_PAGE_DIRTY; return pte; } 249static inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~_PAGE_ACCESSED; return pte; } 250static inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= _PAGE_DIRTY; return pte; } 251static inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= _PAGE_ACCESSED; return pte; } 252static inline pte_t pte_mkexec(pte_t pte) { pte_val(pte) &= ~_PAGE_NX; return pte; } 253 254static inline pte_t pte_mkread(pte_t pte) 255{ 256 pte_val(pte) |= __PAGE_PROT_USER; 257 if (pte_write(pte)) 258 pte_val(pte) |= __PAGE_PROT_UWAUX; 259 return pte; 260} 261static inline pte_t pte_mkwrite(pte_t pte) 262{ 263 pte_val(pte) |= __PAGE_PROT_WRITE; 264 if (pte_val(pte) & __PAGE_PROT_USER) 265 pte_val(pte) |= __PAGE_PROT_UWAUX; 266 return pte; 267} 268 269static inline pte_t pte_mkspecial(pte_t pte) { return pte; } 270 271#define pte_ERROR(e) \ 272 printk(KERN_ERR "%s:%d: bad pte %08lx.\n", \ 273 __FILE__, __LINE__, pte_val(e)) 274#define pgd_ERROR(e) \ 275 printk(KERN_ERR "%s:%d: bad pgd %08lx.\n", \ 276 __FILE__, __LINE__, pgd_val(e)) 277 278/* 279 * The "pgd_xxx()" functions here are trivial for a folded two-level 280 * setup: the pgd is never bad, and a pmd always exists (as it's folded 281 * into the pgd entry) 282 */ 283#define pgd_clear(xp) do { } while (0) 284 285/* 286 * Certain architectures need to do special things when PTEs 287 * within a page table are directly modified. Thus, the following 288 * hook is made available. 289 */ 290#define set_pte(pteptr, pteval) (*(pteptr) = pteval) 291#define set_pte_at(mm, addr, ptep, pteval) set_pte((ptep), (pteval)) 292#define set_pte_atomic(pteptr, pteval) set_pte((pteptr), (pteval)) 293 294/* 295 * (pmds are folded into pgds so this doesn't get actually called, 296 * but the define is needed for a generic inline function.) 297 */ 298#define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval) 299 300#define ptep_get_and_clear(mm, addr, ptep) \ 301 __pte(xchg(&(ptep)->pte, 0)) 302#define pte_same(a, b) (pte_val(a) == pte_val(b)) 303#define pte_page(x) pfn_to_page(pte_pfn(x)) 304#define pte_none(x) (!pte_val(x)) 305#define pte_pfn(x) ((unsigned long) (pte_val(x) >> PAGE_SHIFT)) 306#define __pfn_addr(pfn) ((pfn) << PAGE_SHIFT) 307#define pfn_pte(pfn, prot) __pte(__pfn_addr(pfn) | pgprot_val(prot)) 308#define pfn_pmd(pfn, prot) __pmd(__pfn_addr(pfn) | pgprot_val(prot)) 309 310/* 311 * All present user pages are user-executable: 312 */ 313static inline int pte_exec(pte_t pte) 314{ 315 return pte_user(pte); 316} 317 318/* 319 * All present pages are kernel-executable: 320 */ 321static inline int pte_exec_kernel(pte_t pte) 322{ 323 return 1; 324} 325 326/* 327 * Bits 0 and 1 are taken, split up the 29 bits of offset 328 * into this range: 329 */ 330#define PTE_FILE_MAX_BITS 29 331 332#define pte_to_pgoff(pte) (pte_val(pte) >> 2) 333#define pgoff_to_pte(off) __pte((off) << 2 | _PAGE_FILE) 334 335/* Encode and de-code a swap entry */ 336#define __swp_type(x) (((x).val >> 2) & 0x3f) 337#define __swp_offset(x) ((x).val >> 8) 338#define __swp_entry(type, offset) \ 339 ((swp_entry_t) { ((type) << 2) | ((offset) << 8) }) 340#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 341#define __swp_entry_to_pte(x) __pte((x).val) 342 343static inline 344int ptep_test_and_clear_dirty(struct vm_area_struct *vma, unsigned long addr, 345 pte_t *ptep) 346{ 347 if (!pte_dirty(*ptep)) 348 return 0; 349 return test_and_clear_bit(_PAGE_BIT_DIRTY, &ptep->pte); 350} 351 352static inline 353int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, 354 pte_t *ptep) 355{ 356 if (!pte_young(*ptep)) 357 return 0; 358 return test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte); 359} 360 361static inline 362void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) 363{ 364 pte_val(*ptep) &= ~(__PAGE_PROT_WRITE|__PAGE_PROT_UWAUX); 365} 366 367static inline void ptep_mkdirty(pte_t *ptep) 368{ 369 set_bit(_PAGE_BIT_DIRTY, &ptep->pte); 370} 371 372/* 373 * Macro to mark a page protection value as "uncacheable". On processors which 374 * do not support it, this is a no-op. 375 */ 376#define pgprot_noncached(prot) __pgprot(pgprot_val(prot) | _PAGE_CACHE) 377 378 379/* 380 * Conversion functions: convert a page and protection to a page entry, 381 * and a page entry and page directory to the page they refer to. 382 */ 383 384#define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot)) 385#define mk_pte_huge(entry) \ 386 ((entry).pte |= _PAGE_PRESENT | _PAGE_PSE | _PAGE_VALID) 387 388static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 389{ 390 pte_val(pte) &= _PAGE_CHG_MASK; 391 pte_val(pte) |= pgprot_val(newprot); 392 return pte; 393} 394 395#define page_pte(page) page_pte_prot((page), __pgprot(0)) 396 397#define pmd_page_kernel(pmd) \ 398 ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK)) 399 400#define pmd_page(pmd) pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT) 401 402#define pmd_large(pmd) \ 403 ((pmd_val(pmd) & (_PAGE_PSE | _PAGE_PRESENT)) == \ 404 (_PAGE_PSE | _PAGE_PRESENT)) 405 406/* 407 * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD] 408 * 409 * this macro returns the index of the entry in the pgd page which would 410 * control the given virtual address 411 */ 412#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)) 413 414/* 415 * pgd_offset() returns a (pgd_t *) 416 * pgd_index() is used get the offset into the pgd page's array of pgd_t's; 417 */ 418#define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address)) 419 420/* 421 * a shortcut which implies the use of the kernel's pgd, instead 422 * of a process's 423 */ 424#define pgd_offset_k(address) pgd_offset(&init_mm, address) 425 426/* 427 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD] 428 * 429 * this macro returns the index of the entry in the pmd page which would 430 * control the given virtual address 431 */ 432#define pmd_index(address) \ 433 (((address) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)) 434 435/* 436 * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE] 437 * 438 * this macro returns the index of the entry in the pte page which would 439 * control the given virtual address 440 */ 441#define pte_index(address) \ 442 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 443 444#define pte_offset_kernel(dir, address) \ 445 ((pte_t *) pmd_page_kernel(*(dir)) + pte_index(address)) 446 447/* 448 * Make a given kernel text page executable/non-executable. 449 * Returns the previous executability setting of that page (which 450 * is used to restore the previous state). Used by the SMP bootup code. 451 * NOTE: this is an __init function for security reasons. 452 */ 453static inline int set_kernel_exec(unsigned long vaddr, int enable) 454{ 455 return 0; 456} 457 458#define pte_offset_map(dir, address) \ 459 ((pte_t *) page_address(pmd_page(*(dir))) + pte_index(address)) 460#define pte_offset_map_nested(dir, address) pte_offset_map(dir, address) 461#define pte_unmap(pte) do {} while (0) 462#define pte_unmap_nested(pte) do {} while (0) 463 464/* 465 * The MN10300 has external MMU info in the form of a TLB: this is adapted from 466 * the kernel page tables containing the necessary information by tlb-mn10300.S 467 */ 468extern void update_mmu_cache(struct vm_area_struct *vma, 469 unsigned long address, pte_t *ptep); 470 471#endif /* !__ASSEMBLY__ */ 472 473#define kern_addr_valid(addr) (1) 474 475#define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \ 476 remap_pfn_range((vma), (vaddr), (pfn), (size), (prot)) 477 478#define MK_IOSPACE_PFN(space, pfn) (pfn) 479#define GET_IOSPACE(pfn) 0 480#define GET_PFN(pfn) (pfn) 481 482#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG 483#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY 484#define __HAVE_ARCH_PTEP_GET_AND_CLEAR 485#define __HAVE_ARCH_PTEP_SET_WRPROTECT 486#define __HAVE_ARCH_PTEP_MKDIRTY 487#define __HAVE_ARCH_PTE_SAME 488#include <asm-generic/pgtable.h> 489 490#endif /* !__ASSEMBLY__ */ 491 492#endif /* _ASM_PGTABLE_H */ 493