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David Howellsb920de12008-02-08 04:19:31 -08001/* 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; }
Nick Piggin7e675132008-04-28 02:13:00 -0700227static inline int pte_special(pte_t pte){ return 0; }
David Howellsb920de12008-02-08 04:19:31 -0800228
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
Nick Piggin7e675132008-04-28 02:13:00 -0700269static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
270
David Howellsb920de12008-02-08 04:19:31 -0800271#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 pte);
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 */