1#ifndef _ALPHA_PGTABLE_H 2#define _ALPHA_PGTABLE_H 3 4#include <asm-generic/4level-fixup.h> 5 6/* 7 * This file contains the functions and defines necessary to modify and use 8 * the Alpha page table tree. 9 * 10 * This hopefully works with any standard Alpha page-size, as defined 11 * in <asm/page.h> (currently 8192). 12 */ 13#include <linux/mmzone.h> 14 15#include <asm/page.h> 16#include <asm/processor.h> /* For TASK_SIZE */ 17#include <asm/machvec.h> 18 19struct mm_struct; 20struct vm_area_struct; 21 22/* Certain architectures need to do special things when PTEs 23 * within a page table are directly modified. Thus, the following 24 * hook is made available. 25 */ 26#define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval)) 27#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval) 28 29/* PMD_SHIFT determines the size of the area a second-level page table can map */ 30#define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT-3)) 31#define PMD_SIZE (1UL << PMD_SHIFT) 32#define PMD_MASK (~(PMD_SIZE-1)) 33 34/* PGDIR_SHIFT determines what a third-level page table entry can map */ 35#define PGDIR_SHIFT (PAGE_SHIFT + 2*(PAGE_SHIFT-3)) 36#define PGDIR_SIZE (1UL << PGDIR_SHIFT) 37#define PGDIR_MASK (~(PGDIR_SIZE-1)) 38 39/* 40 * Entries per page directory level: the Alpha is three-level, with 41 * all levels having a one-page page table. 42 */ 43#define PTRS_PER_PTE (1UL << (PAGE_SHIFT-3)) 44#define PTRS_PER_PMD (1UL << (PAGE_SHIFT-3)) 45#define PTRS_PER_PGD (1UL << (PAGE_SHIFT-3)) 46#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) 47#define FIRST_USER_ADDRESS 0 48 49/* Number of pointers that fit on a page: this will go away. */ 50#define PTRS_PER_PAGE (1UL << (PAGE_SHIFT-3)) 51 52#ifdef CONFIG_ALPHA_LARGE_VMALLOC 53#define VMALLOC_START 0xfffffe0000000000 54#else 55#define VMALLOC_START (-2*PGDIR_SIZE) 56#endif 57#define VMALLOC_END (-PGDIR_SIZE) 58 59/* 60 * OSF/1 PAL-code-imposed page table bits 61 */ 62#define _PAGE_VALID 0x0001 63#define _PAGE_FOR 0x0002 /* used for page protection (fault on read) */ 64#define _PAGE_FOW 0x0004 /* used for page protection (fault on write) */ 65#define _PAGE_FOE 0x0008 /* used for page protection (fault on exec) */ 66#define _PAGE_ASM 0x0010 67#define _PAGE_KRE 0x0100 68#define _PAGE_URE 0x0200 69#define _PAGE_KWE 0x1000 /* used to do the dirty bit in software */ 70#define _PAGE_UWE 0x2000 /* used to do the dirty bit in software */ 71 72/* .. and these are ours ... */ 73#define _PAGE_DIRTY 0x20000 74#define _PAGE_ACCESSED 0x40000 75#define _PAGE_FILE 0x80000 /* set:pagecache, unset:swap */ 76 77/* 78 * NOTE! The "accessed" bit isn't necessarily exact: it can be kept exactly 79 * by software (use the KRE/URE/KWE/UWE bits appropriately), but I'll fake it. 80 * Under Linux/AXP, the "accessed" bit just means "read", and I'll just use 81 * the KRE/URE bits to watch for it. That way we don't need to overload the 82 * KWE/UWE bits with both handling dirty and accessed. 83 * 84 * Note that the kernel uses the accessed bit just to check whether to page 85 * out a page or not, so it doesn't have to be exact anyway. 86 */ 87 88#define __DIRTY_BITS (_PAGE_DIRTY | _PAGE_KWE | _PAGE_UWE) 89#define __ACCESS_BITS (_PAGE_ACCESSED | _PAGE_KRE | _PAGE_URE) 90 91#define _PFN_MASK 0xFFFFFFFF00000000UL 92 93#define _PAGE_TABLE (_PAGE_VALID | __DIRTY_BITS | __ACCESS_BITS) 94#define _PAGE_CHG_MASK (_PFN_MASK | __DIRTY_BITS | __ACCESS_BITS) 95 96/* 97 * All the normal masks have the "page accessed" bits on, as any time they are used, 98 * the page is accessed. They are cleared only by the page-out routines 99 */ 100#define PAGE_NONE __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOR | _PAGE_FOW | _PAGE_FOE) 101#define PAGE_SHARED __pgprot(_PAGE_VALID | __ACCESS_BITS) 102#define PAGE_COPY __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOW) 103#define PAGE_READONLY __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOW) 104#define PAGE_KERNEL __pgprot(_PAGE_VALID | _PAGE_ASM | _PAGE_KRE | _PAGE_KWE) 105 106#define _PAGE_NORMAL(x) __pgprot(_PAGE_VALID | __ACCESS_BITS | (x)) 107 108#define _PAGE_P(x) _PAGE_NORMAL((x) | (((x) & _PAGE_FOW)?0:_PAGE_FOW)) 109#define _PAGE_S(x) _PAGE_NORMAL(x) 110 111/* 112 * The hardware can handle write-only mappings, but as the Alpha 113 * architecture does byte-wide writes with a read-modify-write 114 * sequence, it's not practical to have write-without-read privs. 115 * Thus the "-w- -> rw-" and "-wx -> rwx" mapping here (and in 116 * arch/alpha/mm/fault.c) 117 */ 118 /* xwr */ 119#define __P000 _PAGE_P(_PAGE_FOE | _PAGE_FOW | _PAGE_FOR) 120#define __P001 _PAGE_P(_PAGE_FOE | _PAGE_FOW) 121#define __P010 _PAGE_P(_PAGE_FOE) 122#define __P011 _PAGE_P(_PAGE_FOE) 123#define __P100 _PAGE_P(_PAGE_FOW | _PAGE_FOR) 124#define __P101 _PAGE_P(_PAGE_FOW) 125#define __P110 _PAGE_P(0) 126#define __P111 _PAGE_P(0) 127 128#define __S000 _PAGE_S(_PAGE_FOE | _PAGE_FOW | _PAGE_FOR) 129#define __S001 _PAGE_S(_PAGE_FOE | _PAGE_FOW) 130#define __S010 _PAGE_S(_PAGE_FOE) 131#define __S011 _PAGE_S(_PAGE_FOE) 132#define __S100 _PAGE_S(_PAGE_FOW | _PAGE_FOR) 133#define __S101 _PAGE_S(_PAGE_FOW) 134#define __S110 _PAGE_S(0) 135#define __S111 _PAGE_S(0) 136 137/* 138 * pgprot_noncached() is only for infiniband pci support, and a real 139 * implementation for RAM would be more complicated. 140 */ 141#define pgprot_noncached(prot) (prot) 142 143/* 144 * BAD_PAGETABLE is used when we need a bogus page-table, while 145 * BAD_PAGE is used for a bogus page. 146 * 147 * ZERO_PAGE is a global shared page that is always zero: used 148 * for zero-mapped memory areas etc.. 149 */ 150extern pte_t __bad_page(void); 151extern pmd_t * __bad_pagetable(void); 152 153extern unsigned long __zero_page(void); 154 155#define BAD_PAGETABLE __bad_pagetable() 156#define BAD_PAGE __bad_page() 157#define ZERO_PAGE(vaddr) (virt_to_page(ZERO_PGE)) 158 159/* number of bits that fit into a memory pointer */ 160#define BITS_PER_PTR (8*sizeof(unsigned long)) 161 162/* to align the pointer to a pointer address */ 163#define PTR_MASK (~(sizeof(void*)-1)) 164 165/* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */ 166#define SIZEOF_PTR_LOG2 3 167 168/* to find an entry in a page-table */ 169#define PAGE_PTR(address) \ 170 ((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK) 171 172/* 173 * On certain platforms whose physical address space can overlap KSEG, 174 * namely EV6 and above, we must re-twiddle the physaddr to restore the 175 * correct high-order bits. 176 * 177 * This is extremely confusing until you realize that this is actually 178 * just working around a userspace bug. The X server was intending to 179 * provide the physical address but instead provided the KSEG address. 180 * Or tried to, except it's not representable. 181 * 182 * On Tsunami there's nothing meaningful at 0x40000000000, so this is 183 * a safe thing to do. Come the first core logic that does put something 184 * in this area -- memory or whathaveyou -- then this hack will have 185 * to go away. So be prepared! 186 */ 187 188#if defined(CONFIG_ALPHA_GENERIC) && defined(USE_48_BIT_KSEG) 189#error "EV6-only feature in a generic kernel" 190#endif 191#if defined(CONFIG_ALPHA_GENERIC) || (defined(CONFIG_ALPHA_EV6) && \ 192 !defined(USE_48_BIT_KSEG)) 193#define KSEG_PFN (0xc0000000000UL >> PAGE_SHIFT) 194#define PHYS_TWIDDLE(pfn) \ 195 ((((pfn) & KSEG_PFN) == (0x40000000000UL >> PAGE_SHIFT)) \ 196 ? ((pfn) ^= KSEG_PFN) : (pfn)) 197#else 198#define PHYS_TWIDDLE(pfn) (pfn) 199#endif 200 201/* 202 * Conversion functions: convert a page and protection to a page entry, 203 * and a page entry and page directory to the page they refer to. 204 */ 205#ifndef CONFIG_DISCONTIGMEM 206#define page_to_pa(page) (((page) - mem_map) << PAGE_SHIFT) 207 208#define pte_pfn(pte) (pte_val(pte) >> 32) 209#define pte_page(pte) pfn_to_page(pte_pfn(pte)) 210#define mk_pte(page, pgprot) \ 211({ \ 212 pte_t pte; \ 213 \ 214 pte_val(pte) = (page_to_pfn(page) << 32) | pgprot_val(pgprot); \ 215 pte; \ 216}) 217#endif 218 219extern inline pte_t pfn_pte(unsigned long physpfn, pgprot_t pgprot) 220{ pte_t pte; pte_val(pte) = (PHYS_TWIDDLE(physpfn) << 32) | pgprot_val(pgprot); return pte; } 221 222extern inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 223{ pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; } 224 225extern inline void pmd_set(pmd_t * pmdp, pte_t * ptep) 226{ pmd_val(*pmdp) = _PAGE_TABLE | ((((unsigned long) ptep) - PAGE_OFFSET) << (32-PAGE_SHIFT)); } 227 228extern inline void pgd_set(pgd_t * pgdp, pmd_t * pmdp) 229{ pgd_val(*pgdp) = _PAGE_TABLE | ((((unsigned long) pmdp) - PAGE_OFFSET) << (32-PAGE_SHIFT)); } 230 231 232extern inline unsigned long 233pmd_page_vaddr(pmd_t pmd) 234{ 235 return ((pmd_val(pmd) & _PFN_MASK) >> (32-PAGE_SHIFT)) + PAGE_OFFSET; 236} 237 238#ifndef CONFIG_DISCONTIGMEM 239#define pmd_page(pmd) (mem_map + ((pmd_val(pmd) & _PFN_MASK) >> 32)) 240#define pgd_page(pgd) (mem_map + ((pgd_val(pgd) & _PFN_MASK) >> 32)) 241#endif 242 243extern inline unsigned long pgd_page_vaddr(pgd_t pgd) 244{ return PAGE_OFFSET + ((pgd_val(pgd) & _PFN_MASK) >> (32-PAGE_SHIFT)); } 245 246extern inline int pte_none(pte_t pte) { return !pte_val(pte); } 247extern inline int pte_present(pte_t pte) { return pte_val(pte) & _PAGE_VALID; } 248extern inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) 249{ 250 pte_val(*ptep) = 0; 251} 252 253extern inline int pmd_none(pmd_t pmd) { return !pmd_val(pmd); } 254extern inline int pmd_bad(pmd_t pmd) { return (pmd_val(pmd) & ~_PFN_MASK) != _PAGE_TABLE; } 255extern inline int pmd_present(pmd_t pmd) { return pmd_val(pmd) & _PAGE_VALID; } 256extern inline void pmd_clear(pmd_t * pmdp) { pmd_val(*pmdp) = 0; } 257 258extern inline int pgd_none(pgd_t pgd) { return !pgd_val(pgd); } 259extern inline int pgd_bad(pgd_t pgd) { return (pgd_val(pgd) & ~_PFN_MASK) != _PAGE_TABLE; } 260extern inline int pgd_present(pgd_t pgd) { return pgd_val(pgd) & _PAGE_VALID; } 261extern inline void pgd_clear(pgd_t * pgdp) { pgd_val(*pgdp) = 0; } 262 263/* 264 * The following only work if pte_present() is true. 265 * Undefined behaviour if not.. 266 */ 267extern inline int pte_read(pte_t pte) { return !(pte_val(pte) & _PAGE_FOR); } 268extern inline int pte_write(pte_t pte) { return !(pte_val(pte) & _PAGE_FOW); } 269extern inline int pte_exec(pte_t pte) { return !(pte_val(pte) & _PAGE_FOE); } 270extern inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; } 271extern inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; } 272extern inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; } 273 274extern inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) |= _PAGE_FOW; return pte; } 275extern inline pte_t pte_rdprotect(pte_t pte) { pte_val(pte) |= _PAGE_FOR; return pte; } 276extern inline pte_t pte_exprotect(pte_t pte) { pte_val(pte) |= _PAGE_FOE; return pte; } 277extern inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~(__DIRTY_BITS); return pte; } 278extern inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~(__ACCESS_BITS); return pte; } 279extern inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) &= ~_PAGE_FOW; return pte; } 280extern inline pte_t pte_mkread(pte_t pte) { pte_val(pte) &= ~_PAGE_FOR; return pte; } 281extern inline pte_t pte_mkexec(pte_t pte) { pte_val(pte) &= ~_PAGE_FOE; return pte; } 282extern inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= __DIRTY_BITS; return pte; } 283extern inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= __ACCESS_BITS; return pte; } 284 285#define PAGE_DIR_OFFSET(tsk,address) pgd_offset((tsk),(address)) 286 287/* to find an entry in a kernel page-table-directory */ 288#define pgd_offset_k(address) pgd_offset(&init_mm, (address)) 289 290/* to find an entry in a page-table-directory. */ 291#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1)) 292#define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address)) 293 294/* Find an entry in the second-level page table.. */ 295extern inline pmd_t * pmd_offset(pgd_t * dir, unsigned long address) 296{ 297 return (pmd_t *) pgd_page_vaddr(*dir) + ((address >> PMD_SHIFT) & (PTRS_PER_PAGE - 1)); 298} 299 300/* Find an entry in the third-level page table.. */ 301extern inline pte_t * pte_offset_kernel(pmd_t * dir, unsigned long address) 302{ 303 return (pte_t *) pmd_page_vaddr(*dir) 304 + ((address >> PAGE_SHIFT) & (PTRS_PER_PAGE - 1)); 305} 306 307#define pte_offset_map(dir,addr) pte_offset_kernel((dir),(addr)) 308#define pte_offset_map_nested(dir,addr) pte_offset_kernel((dir),(addr)) 309#define pte_unmap(pte) do { } while (0) 310#define pte_unmap_nested(pte) do { } while (0) 311 312extern pgd_t swapper_pg_dir[1024]; 313 314/* 315 * The Alpha doesn't have any external MMU info: the kernel page 316 * tables contain all the necessary information. 317 */ 318extern inline void update_mmu_cache(struct vm_area_struct * vma, 319 unsigned long address, pte_t pte) 320{ 321} 322 323/* 324 * Non-present pages: high 24 bits are offset, next 8 bits type, 325 * low 32 bits zero. 326 */ 327extern inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) 328{ pte_t pte; pte_val(pte) = (type << 32) | (offset << 40); return pte; } 329 330#define __swp_type(x) (((x).val >> 32) & 0xff) 331#define __swp_offset(x) ((x).val >> 40) 332#define __swp_entry(type, off) ((swp_entry_t) { pte_val(mk_swap_pte((type), (off))) }) 333#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 334#define __swp_entry_to_pte(x) ((pte_t) { (x).val }) 335 336#define pte_to_pgoff(pte) (pte_val(pte) >> 32) 337#define pgoff_to_pte(off) ((pte_t) { ((off) << 32) | _PAGE_FILE }) 338 339#define PTE_FILE_MAX_BITS 32 340 341#ifndef CONFIG_DISCONTIGMEM 342#define kern_addr_valid(addr) (1) 343#endif 344 345#define io_remap_pfn_range(vma, start, pfn, size, prot) \ 346 remap_pfn_range(vma, start, pfn, size, prot) 347 348#define pte_ERROR(e) \ 349 printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e)) 350#define pmd_ERROR(e) \ 351 printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e)) 352#define pgd_ERROR(e) \ 353 printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e)) 354 355extern void paging_init(void); 356 357#include <asm-generic/pgtable.h> 358 359/* 360 * No page table caches to initialise 361 */ 362#define pgtable_cache_init() do { } while (0) 363 364/* We have our own get_unmapped_area to cope with ADDR_LIMIT_32BIT. */ 365#define HAVE_ARCH_UNMAPPED_AREA 366 367#endif /* _ALPHA_PGTABLE_H */ 368