1 /* MN10300 Page table manipulators and constants
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
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.
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
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
21 #ifndef _ASM_PGTABLE_H
22 #define _ASM_PGTABLE_H
24 #include <asm/cpu-regs.h>
27 #include <asm/processor.h>
28 #include <asm/cache.h>
29 #include <linux/threads.h>
31 #include <asm/bitops.h>
33 #include <linux/slab.h>
34 #include <linux/list.h>
35 #include <linux/spinlock.h>
38 * ZERO_PAGE is a global shared page that is always zero: used
39 * for zero-mapped memory areas etc..
41 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
42 extern unsigned long empty_zero_page
[1024];
43 extern spinlock_t pgd_lock
;
44 extern struct page
*pgd_list
;
46 extern void pmd_ctor(void *, struct kmem_cache
*, unsigned long);
47 extern void pgtable_cache_init(void);
48 extern void paging_init(void);
50 #endif /* !__ASSEMBLY__ */
53 * The Linux mn10300 paging architecture only implements both the traditional
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 __PAGETABLE_PUD_FOLDED
60 #define PTRS_PER_PMD 1 /* we don't really have any PMD physically */
61 #define __PAGETABLE_PMD_FOLDED
62 #define PTRS_PER_PTE 1024
64 #define PGD_SIZE PAGE_SIZE
65 #define PMD_SIZE (1UL << PMD_SHIFT)
66 #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
67 #define PGDIR_MASK (~(PGDIR_SIZE - 1))
69 #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
70 #define FIRST_USER_ADDRESS 0UL
72 #define USER_PGD_PTRS (PAGE_OFFSET >> PGDIR_SHIFT)
73 #define KERNEL_PGD_PTRS (PTRS_PER_PGD - USER_PGD_PTRS)
75 #define TWOLEVEL_PGDIR_SHIFT 22
76 #define BOOT_USER_PGD_PTRS (__PAGE_OFFSET >> TWOLEVEL_PGDIR_SHIFT)
77 #define BOOT_KERNEL_PGD_PTRS (1024 - BOOT_USER_PGD_PTRS)
80 extern pgd_t swapper_pg_dir
[PTRS_PER_PGD
];
84 * Unfortunately, due to the way the MMU works on the MN10300, the vmalloc VM
85 * area has to be in the lower half of the virtual address range (the upper
86 * half is not translated through the TLB).
88 * So in this case, the vmalloc area goes at the bottom of the address map
89 * (leaving a hole at the very bottom to catch addressing errors), and
90 * userspace starts immediately above.
92 * The vmalloc() routines also leaves a hole of 4kB between each vmalloced
93 * area to catch addressing errors.
96 #define VMALLOC_OFFSET (8UL * 1024 * 1024)
97 #define VMALLOC_START (0x70000000UL)
98 #define VMALLOC_END (0x7C000000UL)
100 #define VMALLOC_OFFSET (8 * 1024 * 1024)
101 #define VMALLOC_START (0x70000000)
102 #define VMALLOC_END (0x7C000000)
106 extern pte_t kernel_vmalloc_ptes
[(VMALLOC_END
- VMALLOC_START
) / PAGE_SIZE
];
109 /* IPTEL2/DPTEL2 bit assignments */
110 #define _PAGE_BIT_VALID xPTEL2_V_BIT
111 #define _PAGE_BIT_CACHE xPTEL2_C_BIT
112 #define _PAGE_BIT_PRESENT xPTEL2_PV_BIT
113 #define _PAGE_BIT_DIRTY xPTEL2_D_BIT
114 #define _PAGE_BIT_GLOBAL xPTEL2_G_BIT
115 #define _PAGE_BIT_ACCESSED xPTEL2_UNUSED1_BIT /* mustn't be loaded into IPTEL2/DPTEL2 */
117 #define _PAGE_VALID xPTEL2_V
118 #define _PAGE_CACHE xPTEL2_C
119 #define _PAGE_PRESENT xPTEL2_PV
120 #define _PAGE_DIRTY xPTEL2_D
121 #define _PAGE_PROT xPTEL2_PR
122 #define _PAGE_PROT_RKNU xPTEL2_PR_ROK
123 #define _PAGE_PROT_WKNU xPTEL2_PR_RWK
124 #define _PAGE_PROT_RKRU xPTEL2_PR_ROK_ROU
125 #define _PAGE_PROT_WKRU xPTEL2_PR_RWK_ROU
126 #define _PAGE_PROT_WKWU xPTEL2_PR_RWK_RWU
127 #define _PAGE_GLOBAL xPTEL2_G
128 #define _PAGE_PS_MASK xPTEL2_PS
129 #define _PAGE_PS_4Kb xPTEL2_PS_4Kb
130 #define _PAGE_PS_128Kb xPTEL2_PS_128Kb
131 #define _PAGE_PS_1Kb xPTEL2_PS_1Kb
132 #define _PAGE_PS_4Mb xPTEL2_PS_4Mb
133 #define _PAGE_PSE xPTEL2_PS_4Mb /* 4MB page */
134 #define _PAGE_CACHE_WT xPTEL2_CWT
135 #define _PAGE_ACCESSED xPTEL2_UNUSED1
136 #define _PAGE_NX 0 /* no-execute bit */
138 /* If _PAGE_VALID is clear, we use these: */
139 #define _PAGE_PROTNONE 0x000 /* If not present */
141 #define __PAGE_PROT_UWAUX 0x010
142 #define __PAGE_PROT_USER 0x020
143 #define __PAGE_PROT_WRITE 0x040
145 #define _PAGE_PRESENTV (_PAGE_PRESENT|_PAGE_VALID)
149 #define VMALLOC_VMADDR(x) ((unsigned long)(x))
151 #define _PAGE_TABLE (_PAGE_PRESENTV | _PAGE_PROT_WKNU | _PAGE_ACCESSED | _PAGE_DIRTY)
152 #define _PAGE_CHG_MASK (PTE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
154 #define __PAGE_NONE (_PAGE_PRESENTV | _PAGE_PROT_RKNU | _PAGE_ACCESSED | _PAGE_CACHE)
155 #define __PAGE_SHARED (_PAGE_PRESENTV | _PAGE_PROT_WKWU | _PAGE_ACCESSED | _PAGE_CACHE)
156 #define __PAGE_COPY (_PAGE_PRESENTV | _PAGE_PROT_RKRU | _PAGE_ACCESSED | _PAGE_CACHE)
157 #define __PAGE_READONLY (_PAGE_PRESENTV | _PAGE_PROT_RKRU | _PAGE_ACCESSED | _PAGE_CACHE)
159 #define PAGE_NONE __pgprot(__PAGE_NONE | _PAGE_NX)
160 #define PAGE_SHARED_NOEXEC __pgprot(__PAGE_SHARED | _PAGE_NX)
161 #define PAGE_COPY_NOEXEC __pgprot(__PAGE_COPY | _PAGE_NX)
162 #define PAGE_READONLY_NOEXEC __pgprot(__PAGE_READONLY | _PAGE_NX)
163 #define PAGE_SHARED_EXEC __pgprot(__PAGE_SHARED)
164 #define PAGE_COPY_EXEC __pgprot(__PAGE_COPY)
165 #define PAGE_READONLY_EXEC __pgprot(__PAGE_READONLY)
166 #define PAGE_COPY PAGE_COPY_NOEXEC
167 #define PAGE_READONLY PAGE_READONLY_NOEXEC
168 #define PAGE_SHARED PAGE_SHARED_EXEC
170 #define __PAGE_KERNEL_BASE (_PAGE_PRESENTV | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_GLOBAL)
172 #define __PAGE_KERNEL (__PAGE_KERNEL_BASE | _PAGE_PROT_WKNU | _PAGE_CACHE | _PAGE_NX)
173 #define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL_BASE | _PAGE_PROT_WKNU | _PAGE_NX)
174 #define __PAGE_KERNEL_EXEC (__PAGE_KERNEL & ~_PAGE_NX)
175 #define __PAGE_KERNEL_RO (__PAGE_KERNEL_BASE | _PAGE_PROT_RKNU | _PAGE_CACHE | _PAGE_NX)
176 #define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE)
177 #define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE)
179 #define PAGE_KERNEL __pgprot(__PAGE_KERNEL)
180 #define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO)
181 #define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC)
182 #define PAGE_KERNEL_NOCACHE __pgprot(__PAGE_KERNEL_NOCACHE)
183 #define PAGE_KERNEL_LARGE __pgprot(__PAGE_KERNEL_LARGE)
184 #define PAGE_KERNEL_LARGE_EXEC __pgprot(__PAGE_KERNEL_LARGE_EXEC)
186 #define __PAGE_USERIO (__PAGE_KERNEL_BASE | _PAGE_PROT_WKWU | _PAGE_NX)
187 #define PAGE_USERIO __pgprot(__PAGE_USERIO)
190 * Whilst the MN10300 can do page protection for execute (given separate data
191 * and insn TLBs), we are not supporting it at the moment. Write permission,
192 * however, always implies read permission (but not execute permission).
194 #define __P000 PAGE_NONE
195 #define __P001 PAGE_READONLY_NOEXEC
196 #define __P010 PAGE_COPY_NOEXEC
197 #define __P011 PAGE_COPY_NOEXEC
198 #define __P100 PAGE_READONLY_EXEC
199 #define __P101 PAGE_READONLY_EXEC
200 #define __P110 PAGE_COPY_EXEC
201 #define __P111 PAGE_COPY_EXEC
203 #define __S000 PAGE_NONE
204 #define __S001 PAGE_READONLY_NOEXEC
205 #define __S010 PAGE_SHARED_NOEXEC
206 #define __S011 PAGE_SHARED_NOEXEC
207 #define __S100 PAGE_READONLY_EXEC
208 #define __S101 PAGE_READONLY_EXEC
209 #define __S110 PAGE_SHARED_EXEC
210 #define __S111 PAGE_SHARED_EXEC
213 * Define this to warn about kernel memory accesses that are
214 * done without a 'verify_area(VERIFY_WRITE,..)'
216 #undef TEST_VERIFY_AREA
218 #define pte_present(x) (pte_val(x) & _PAGE_VALID)
219 #define pte_clear(mm, addr, xp) \
221 set_pte_at((mm), (addr), (xp), __pte(0)); \
224 #define pmd_none(x) (!pmd_val(x))
225 #define pmd_present(x) (!pmd_none(x))
226 #define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0)
230 #define pages_to_mb(x) ((x) >> (20 - PAGE_SHIFT))
235 * The following only work if pte_present() is true.
236 * Undefined behaviour if not..
238 static inline int pte_user(pte_t pte
) { return pte_val(pte
) & __PAGE_PROT_USER
; }
239 static inline int pte_read(pte_t pte
) { return pte_val(pte
) & __PAGE_PROT_USER
; }
240 static inline int pte_dirty(pte_t pte
) { return pte_val(pte
) & _PAGE_DIRTY
; }
241 static inline int pte_young(pte_t pte
) { return pte_val(pte
) & _PAGE_ACCESSED
; }
242 static inline int pte_write(pte_t pte
) { return pte_val(pte
) & __PAGE_PROT_WRITE
; }
243 static inline int pte_special(pte_t pte
){ return 0; }
245 static inline pte_t
pte_rdprotect(pte_t pte
)
247 pte_val(pte
) &= ~(__PAGE_PROT_USER
|__PAGE_PROT_UWAUX
); return pte
;
249 static inline pte_t
pte_exprotect(pte_t pte
)
251 pte_val(pte
) |= _PAGE_NX
; return pte
;
254 static inline pte_t
pte_wrprotect(pte_t pte
)
256 pte_val(pte
) &= ~(__PAGE_PROT_WRITE
|__PAGE_PROT_UWAUX
); return pte
;
259 static inline pte_t
pte_mkclean(pte_t pte
) { pte_val(pte
) &= ~_PAGE_DIRTY
; return pte
; }
260 static inline pte_t
pte_mkold(pte_t pte
) { pte_val(pte
) &= ~_PAGE_ACCESSED
; return pte
; }
261 static inline pte_t
pte_mkdirty(pte_t pte
) { pte_val(pte
) |= _PAGE_DIRTY
; return pte
; }
262 static inline pte_t
pte_mkyoung(pte_t pte
) { pte_val(pte
) |= _PAGE_ACCESSED
; return pte
; }
263 static inline pte_t
pte_mkexec(pte_t pte
) { pte_val(pte
) &= ~_PAGE_NX
; return pte
; }
265 static inline pte_t
pte_mkread(pte_t pte
)
267 pte_val(pte
) |= __PAGE_PROT_USER
;
269 pte_val(pte
) |= __PAGE_PROT_UWAUX
;
272 static inline pte_t
pte_mkwrite(pte_t pte
)
274 pte_val(pte
) |= __PAGE_PROT_WRITE
;
275 if (pte_val(pte
) & __PAGE_PROT_USER
)
276 pte_val(pte
) |= __PAGE_PROT_UWAUX
;
280 static inline pte_t
pte_mkspecial(pte_t pte
) { return pte
; }
282 #define pte_ERROR(e) \
283 printk(KERN_ERR "%s:%d: bad pte %08lx.\n", \
284 __FILE__, __LINE__, pte_val(e))
285 #define pgd_ERROR(e) \
286 printk(KERN_ERR "%s:%d: bad pgd %08lx.\n", \
287 __FILE__, __LINE__, pgd_val(e))
290 * The "pgd_xxx()" functions here are trivial for a folded two-level
291 * setup: the pgd is never bad, and a pmd always exists (as it's folded
292 * into the pgd entry)
294 #define pgd_clear(xp) do { } while (0)
297 * Certain architectures need to do special things when PTEs
298 * within a page table are directly modified. Thus, the following
299 * hook is made available.
301 #define set_pte(pteptr, pteval) (*(pteptr) = pteval)
302 #define set_pte_at(mm, addr, ptep, pteval) set_pte((ptep), (pteval))
303 #define set_pte_atomic(pteptr, pteval) set_pte((pteptr), (pteval))
306 * (pmds are folded into pgds so this doesn't get actually called,
307 * but the define is needed for a generic inline function.)
309 #define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)
311 #define ptep_get_and_clear(mm, addr, ptep) \
312 __pte(xchg(&(ptep)->pte, 0))
313 #define pte_same(a, b) (pte_val(a) == pte_val(b))
314 #define pte_page(x) pfn_to_page(pte_pfn(x))
315 #define pte_none(x) (!pte_val(x))
316 #define pte_pfn(x) ((unsigned long) (pte_val(x) >> PAGE_SHIFT))
317 #define __pfn_addr(pfn) ((pfn) << PAGE_SHIFT)
318 #define pfn_pte(pfn, prot) __pte(__pfn_addr(pfn) | pgprot_val(prot))
319 #define pfn_pmd(pfn, prot) __pmd(__pfn_addr(pfn) | pgprot_val(prot))
322 * All present user pages are user-executable:
324 static inline int pte_exec(pte_t pte
)
326 return pte_user(pte
);
330 * All present pages are kernel-executable:
332 static inline int pte_exec_kernel(pte_t pte
)
337 /* Encode and de-code a swap entry */
338 #define __swp_type(x) (((x).val >> 1) & 0x3f)
339 #define __swp_offset(x) ((x).val >> 7)
340 #define __swp_entry(type, offset) \
341 ((swp_entry_t) { ((type) << 1) | ((offset) << 7) })
342 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
343 #define __swp_entry_to_pte(x) __pte((x).val)
346 int ptep_test_and_clear_dirty(struct vm_area_struct
*vma
, unsigned long addr
,
349 if (!pte_dirty(*ptep
))
351 return test_and_clear_bit(_PAGE_BIT_DIRTY
, &ptep
->pte
);
355 int ptep_test_and_clear_young(struct vm_area_struct
*vma
, unsigned long addr
,
358 if (!pte_young(*ptep
))
360 return test_and_clear_bit(_PAGE_BIT_ACCESSED
, &ptep
->pte
);
364 void ptep_set_wrprotect(struct mm_struct
*mm
, unsigned long addr
, pte_t
*ptep
)
366 pte_val(*ptep
) &= ~(__PAGE_PROT_WRITE
|__PAGE_PROT_UWAUX
);
369 static inline void ptep_mkdirty(pte_t
*ptep
)
371 set_bit(_PAGE_BIT_DIRTY
, &ptep
->pte
);
375 * Macro to mark a page protection value as "uncacheable". On processors which
376 * do not support it, this is a no-op.
378 #define pgprot_noncached(prot) __pgprot(pgprot_val(prot) & ~_PAGE_CACHE)
381 * Macro to mark a page protection value as "Write-Through".
382 * On processors which do not support it, this is a no-op.
384 #define pgprot_through(prot) __pgprot(pgprot_val(prot) | _PAGE_CACHE_WT)
387 * Conversion functions: convert a page and protection to a page entry,
388 * and a page entry and page directory to the page they refer to.
391 #define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))
392 #define mk_pte_huge(entry) \
393 ((entry).pte |= _PAGE_PRESENT | _PAGE_PSE | _PAGE_VALID)
395 static inline pte_t
pte_modify(pte_t pte
, pgprot_t newprot
)
397 pte_val(pte
) &= _PAGE_CHG_MASK
;
398 pte_val(pte
) |= pgprot_val(newprot
);
402 #define page_pte(page) page_pte_prot((page), __pgprot(0))
404 #define pmd_page_kernel(pmd) \
405 ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
407 #define pmd_page(pmd) pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
409 #define pmd_large(pmd) \
410 ((pmd_val(pmd) & (_PAGE_PSE | _PAGE_PRESENT)) == \
411 (_PAGE_PSE | _PAGE_PRESENT))
414 * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
416 * this macro returns the index of the entry in the pgd page which would
417 * control the given virtual address
419 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
422 * pgd_offset() returns a (pgd_t *)
423 * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
425 #define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
428 * a shortcut which implies the use of the kernel's pgd, instead
431 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
434 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
436 * this macro returns the index of the entry in the pmd page which would
437 * control the given virtual address
439 #define pmd_index(address) \
440 (((address) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
443 * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
445 * this macro returns the index of the entry in the pte page which would
446 * control the given virtual address
448 #define pte_index(address) \
449 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
451 #define pte_offset_kernel(dir, address) \
452 ((pte_t *) pmd_page_kernel(*(dir)) + pte_index(address))
455 * Make a given kernel text page executable/non-executable.
456 * Returns the previous executability setting of that page (which
457 * is used to restore the previous state). Used by the SMP bootup code.
458 * NOTE: this is an __init function for security reasons.
460 static inline int set_kernel_exec(unsigned long vaddr
, int enable
)
465 #define pte_offset_map(dir, address) \
466 ((pte_t *) page_address(pmd_page(*(dir))) + pte_index(address))
467 #define pte_unmap(pte) do {} while (0)
470 * The MN10300 has external MMU info in the form of a TLB: this is adapted from
471 * the kernel page tables containing the necessary information by tlb-mn10300.S
473 extern void update_mmu_cache(struct vm_area_struct
*vma
,
474 unsigned long address
, pte_t
*ptep
);
476 #endif /* !__ASSEMBLY__ */
478 #define kern_addr_valid(addr) (1)
480 #define MK_IOSPACE_PFN(space, pfn) (pfn)
481 #define GET_IOSPACE(pfn) 0
482 #define GET_PFN(pfn) (pfn)
484 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
485 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
486 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
487 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
488 #define __HAVE_ARCH_PTEP_MKDIRTY
489 #define __HAVE_ARCH_PTE_SAME
490 #include <asm-generic/pgtable.h>
492 #endif /* !__ASSEMBLY__ */
494 #endif /* _ASM_PGTABLE_H */