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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#ifndef __ASSEMBLY__
94#define VMALLOC_OFFSET (8UL * 1024 * 1024)
95#define VMALLOC_START (0x70000000UL)
96#define VMALLOC_END (0x7C000000UL)
97#else
98#define VMALLOC_OFFSET (8 * 1024 * 1024)
99#define VMALLOC_START (0x70000000)
100#define VMALLOC_END (0x7C000000)
101#endif
102
103#ifndef __ASSEMBLY__
104extern pte_t kernel_vmalloc_ptes[(VMALLOC_END - VMALLOC_START) / PAGE_SIZE];
105#endif
106
107/* IPTEL2/DPTEL2 bit assignments */
108#define _PAGE_BIT_VALID xPTEL2_V_BIT
109#define _PAGE_BIT_CACHE xPTEL2_C_BIT
110#define _PAGE_BIT_PRESENT xPTEL2_PV_BIT
111#define _PAGE_BIT_DIRTY xPTEL2_D_BIT
112#define _PAGE_BIT_GLOBAL xPTEL2_G_BIT
113#define _PAGE_BIT_ACCESSED xPTEL2_UNUSED1_BIT /* mustn't be loaded into IPTEL2/DPTEL2 */
114
115#define _PAGE_VALID xPTEL2_V
116#define _PAGE_CACHE xPTEL2_C
117#define _PAGE_PRESENT xPTEL2_PV
118#define _PAGE_DIRTY xPTEL2_D
119#define _PAGE_PROT xPTEL2_PR
120#define _PAGE_PROT_RKNU xPTEL2_PR_ROK
121#define _PAGE_PROT_WKNU xPTEL2_PR_RWK
122#define _PAGE_PROT_RKRU xPTEL2_PR_ROK_ROU
123#define _PAGE_PROT_WKRU xPTEL2_PR_RWK_ROU
124#define _PAGE_PROT_WKWU xPTEL2_PR_RWK_RWU
125#define _PAGE_GLOBAL xPTEL2_G
126#define _PAGE_PS_MASK xPTEL2_PS
127#define _PAGE_PS_4Kb xPTEL2_PS_4Kb
128#define _PAGE_PS_128Kb xPTEL2_PS_128Kb
129#define _PAGE_PS_1Kb xPTEL2_PS_1Kb
130#define _PAGE_PS_4Mb xPTEL2_PS_4Mb
131#define _PAGE_PSE xPTEL2_PS_4Mb /* 4MB page */
132#define _PAGE_CACHE_WT xPTEL2_CWT
133#define _PAGE_ACCESSED xPTEL2_UNUSED1
134#define _PAGE_NX 0 /* no-execute bit */
135
136/* If _PAGE_VALID is clear, we use these: */
137#define _PAGE_FILE xPTEL2_C /* set:pagecache unset:swap */
138#define _PAGE_PROTNONE 0x000 /* If not present */
139
140#define __PAGE_PROT_UWAUX 0x010
141#define __PAGE_PROT_USER 0x020
142#define __PAGE_PROT_WRITE 0x040
143
144#define _PAGE_PRESENTV (_PAGE_PRESENT|_PAGE_VALID)
145
146#ifndef __ASSEMBLY__
147
148#define VMALLOC_VMADDR(x) ((unsigned long)(x))
149
150#define _PAGE_TABLE (_PAGE_PRESENTV | _PAGE_PROT_WKNU | _PAGE_ACCESSED | _PAGE_DIRTY)
151#define _PAGE_CHG_MASK (PTE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
152
153#define __PAGE_NONE (_PAGE_PRESENTV | _PAGE_PROT_RKNU | _PAGE_ACCESSED | _PAGE_CACHE)
154#define __PAGE_SHARED (_PAGE_PRESENTV | _PAGE_PROT_WKWU | _PAGE_ACCESSED | _PAGE_CACHE)
155#define __PAGE_COPY (_PAGE_PRESENTV | _PAGE_PROT_RKRU | _PAGE_ACCESSED | _PAGE_CACHE)
156#define __PAGE_READONLY (_PAGE_PRESENTV | _PAGE_PROT_RKRU | _PAGE_ACCESSED | _PAGE_CACHE)
157
158#define PAGE_NONE __pgprot(__PAGE_NONE | _PAGE_NX)
159#define PAGE_SHARED_NOEXEC __pgprot(__PAGE_SHARED | _PAGE_NX)
160#define PAGE_COPY_NOEXEC __pgprot(__PAGE_COPY | _PAGE_NX)
161#define PAGE_READONLY_NOEXEC __pgprot(__PAGE_READONLY | _PAGE_NX)
162#define PAGE_SHARED_EXEC __pgprot(__PAGE_SHARED)
163#define PAGE_COPY_EXEC __pgprot(__PAGE_COPY)
164#define PAGE_READONLY_EXEC __pgprot(__PAGE_READONLY)
165#define PAGE_COPY PAGE_COPY_NOEXEC
166#define PAGE_READONLY PAGE_READONLY_NOEXEC
167#define PAGE_SHARED PAGE_SHARED_EXEC
168
169#define __PAGE_KERNEL_BASE (_PAGE_PRESENTV | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_GLOBAL)
170
171#define __PAGE_KERNEL (__PAGE_KERNEL_BASE | _PAGE_PROT_WKNU | _PAGE_CACHE | _PAGE_NX)
172#define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL_BASE | _PAGE_PROT_WKNU | _PAGE_NX)
173#define __PAGE_KERNEL_EXEC (__PAGE_KERNEL & ~_PAGE_NX)
174#define __PAGE_KERNEL_RO (__PAGE_KERNEL_BASE | _PAGE_PROT_RKNU | _PAGE_CACHE | _PAGE_NX)
175#define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE)
176#define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE)
177
178#define PAGE_KERNEL __pgprot(__PAGE_KERNEL)
179#define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO)
180#define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC)
181#define PAGE_KERNEL_NOCACHE __pgprot(__PAGE_KERNEL_NOCACHE)
182#define PAGE_KERNEL_LARGE __pgprot(__PAGE_KERNEL_LARGE)
183#define PAGE_KERNEL_LARGE_EXEC __pgprot(__PAGE_KERNEL_LARGE_EXEC)
184
185#define __PAGE_USERIO (__PAGE_KERNEL_BASE | _PAGE_PROT_WKWU | _PAGE_NX)
186#define PAGE_USERIO __pgprot(__PAGE_USERIO)
187
188/*
189 * Whilst the MN10300 can do page protection for execute (given separate data
190 * and insn TLBs), we are not supporting it at the moment. Write permission,
191 * however, always implies read permission (but not execute permission).
192 */
193#define __P000 PAGE_NONE
194#define __P001 PAGE_READONLY_NOEXEC
195#define __P010 PAGE_COPY_NOEXEC
196#define __P011 PAGE_COPY_NOEXEC
197#define __P100 PAGE_READONLY_EXEC
198#define __P101 PAGE_READONLY_EXEC
199#define __P110 PAGE_COPY_EXEC
200#define __P111 PAGE_COPY_EXEC
201
202#define __S000 PAGE_NONE
203#define __S001 PAGE_READONLY_NOEXEC
204#define __S010 PAGE_SHARED_NOEXEC
205#define __S011 PAGE_SHARED_NOEXEC
206#define __S100 PAGE_READONLY_EXEC
207#define __S101 PAGE_READONLY_EXEC
208#define __S110 PAGE_SHARED_EXEC
209#define __S111 PAGE_SHARED_EXEC
210
211/*
212 * Define this to warn about kernel memory accesses that are
213 * done without a 'verify_area(VERIFY_WRITE,..)'
214 */
215#undef TEST_VERIFY_AREA
216
217#define pte_present(x) (pte_val(x) & _PAGE_VALID)
218#define pte_clear(mm, addr, xp) \
219do { \
220 set_pte_at((mm), (addr), (xp), __pte(0)); \
221} while (0)
222
223#define pmd_none(x) (!pmd_val(x))
224#define pmd_present(x) (!pmd_none(x))
225#define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0)
226#define pmd_bad(x) 0
227
228
229#define pages_to_mb(x) ((x) >> (20 - PAGE_SHIFT))
230
231#ifndef __ASSEMBLY__
232
233/*
234 * The following only work if pte_present() is true.
235 * Undefined behaviour if not..
236 */
237static inline int pte_user(pte_t pte) { return pte_val(pte) & __PAGE_PROT_USER; }
238static inline int pte_read(pte_t pte) { return pte_val(pte) & __PAGE_PROT_USER; }
239static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
240static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
241static inline int pte_write(pte_t pte) { return pte_val(pte) & __PAGE_PROT_WRITE; }
242static inline int pte_special(pte_t pte){ return 0; }
243
244/*
245 * The following only works if pte_present() is not true.
246 */
247static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; }
248
249static inline pte_t pte_rdprotect(pte_t pte)
250{
251 pte_val(pte) &= ~(__PAGE_PROT_USER|__PAGE_PROT_UWAUX); return pte;
252}
253static inline pte_t pte_exprotect(pte_t pte)
254{
255 pte_val(pte) |= _PAGE_NX; return pte;
256}
257
258static inline pte_t pte_wrprotect(pte_t pte)
259{
260 pte_val(pte) &= ~(__PAGE_PROT_WRITE|__PAGE_PROT_UWAUX); return pte;
261}
262
263static inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~_PAGE_DIRTY; return pte; }
264static inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
265static inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= _PAGE_DIRTY; return pte; }
266static inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= _PAGE_ACCESSED; return pte; }
267static inline pte_t pte_mkexec(pte_t pte) { pte_val(pte) &= ~_PAGE_NX; return pte; }
268
269static inline pte_t pte_mkread(pte_t pte)
270{
271 pte_val(pte) |= __PAGE_PROT_USER;
272 if (pte_write(pte))
273 pte_val(pte) |= __PAGE_PROT_UWAUX;
274 return pte;
275}
276static inline pte_t pte_mkwrite(pte_t pte)
277{
278 pte_val(pte) |= __PAGE_PROT_WRITE;
279 if (pte_val(pte) & __PAGE_PROT_USER)
280 pte_val(pte) |= __PAGE_PROT_UWAUX;
281 return pte;
282}
283
284static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
285
286#define pte_ERROR(e) \
287 printk(KERN_ERR "%s:%d: bad pte %08lx.\n", \
288 __FILE__, __LINE__, pte_val(e))
289#define pgd_ERROR(e) \
290 printk(KERN_ERR "%s:%d: bad pgd %08lx.\n", \
291 __FILE__, __LINE__, pgd_val(e))
292
293/*
294 * The "pgd_xxx()" functions here are trivial for a folded two-level
295 * setup: the pgd is never bad, and a pmd always exists (as it's folded
296 * into the pgd entry)
297 */
298#define pgd_clear(xp) do { } while (0)
299
300/*
301 * Certain architectures need to do special things when PTEs
302 * within a page table are directly modified. Thus, the following
303 * hook is made available.
304 */
305#define set_pte(pteptr, pteval) (*(pteptr) = pteval)
306#define set_pte_at(mm, addr, ptep, pteval) set_pte((ptep), (pteval))
307#define set_pte_atomic(pteptr, pteval) set_pte((pteptr), (pteval))
308
309/*
310 * (pmds are folded into pgds so this doesn't get actually called,
311 * but the define is needed for a generic inline function.)
312 */
313#define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)
314
315#define ptep_get_and_clear(mm, addr, ptep) \
316 __pte(xchg(&(ptep)->pte, 0))
317#define pte_same(a, b) (pte_val(a) == pte_val(b))
318#define pte_page(x) pfn_to_page(pte_pfn(x))
319#define pte_none(x) (!pte_val(x))
320#define pte_pfn(x) ((unsigned long) (pte_val(x) >> PAGE_SHIFT))
321#define __pfn_addr(pfn) ((pfn) << PAGE_SHIFT)
322#define pfn_pte(pfn, prot) __pte(__pfn_addr(pfn) | pgprot_val(prot))
323#define pfn_pmd(pfn, prot) __pmd(__pfn_addr(pfn) | pgprot_val(prot))
324
325/*
326 * All present user pages are user-executable:
327 */
328static inline int pte_exec(pte_t pte)
329{
330 return pte_user(pte);
331}
332
333/*
334 * All present pages are kernel-executable:
335 */
336static inline int pte_exec_kernel(pte_t pte)
337{
338 return 1;
339}
340
341#define PTE_FILE_MAX_BITS 30
342
343#define pte_to_pgoff(pte) (pte_val(pte) >> 2)
344#define pgoff_to_pte(off) __pte((off) << 2 | _PAGE_FILE)
345
346/* Encode and de-code a swap entry */
347#define __swp_type(x) (((x).val >> 2) & 0x3f)
348#define __swp_offset(x) ((x).val >> 8)
349#define __swp_entry(type, offset) \
350 ((swp_entry_t) { ((type) << 2) | ((offset) << 8) })
351#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
352#define __swp_entry_to_pte(x) __pte((x).val)
353
354static inline
355int ptep_test_and_clear_dirty(struct vm_area_struct *vma, unsigned long addr,
356 pte_t *ptep)
357{
358 if (!pte_dirty(*ptep))
359 return 0;
360 return test_and_clear_bit(_PAGE_BIT_DIRTY, &ptep->pte);
361}
362
363static inline
364int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr,
365 pte_t *ptep)
366{
367 if (!pte_young(*ptep))
368 return 0;
369 return test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte);
370}
371
372static inline
373void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
374{
375 pte_val(*ptep) &= ~(__PAGE_PROT_WRITE|__PAGE_PROT_UWAUX);
376}
377
378static inline void ptep_mkdirty(pte_t *ptep)
379{
380 set_bit(_PAGE_BIT_DIRTY, &ptep->pte);
381}
382
383/*
384 * Macro to mark a page protection value as "uncacheable". On processors which
385 * do not support it, this is a no-op.
386 */
387#define pgprot_noncached(prot) __pgprot(pgprot_val(prot) & ~_PAGE_CACHE)
388
389/*
390 * Macro to mark a page protection value as "Write-Through".
391 * On processors which do not support it, this is a no-op.
392 */
393#define pgprot_through(prot) __pgprot(pgprot_val(prot) | _PAGE_CACHE_WT)
394
395/*
396 * Conversion functions: convert a page and protection to a page entry,
397 * and a page entry and page directory to the page they refer to.
398 */
399
400#define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))
401#define mk_pte_huge(entry) \
402 ((entry).pte |= _PAGE_PRESENT | _PAGE_PSE | _PAGE_VALID)
403
404static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
405{
406 pte_val(pte) &= _PAGE_CHG_MASK;
407 pte_val(pte) |= pgprot_val(newprot);
408 return pte;
409}
410
411#define page_pte(page) page_pte_prot((page), __pgprot(0))
412
413#define pmd_page_kernel(pmd) \
414 ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
415
416#define pmd_page(pmd) pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
417
418#define pmd_large(pmd) \
419 ((pmd_val(pmd) & (_PAGE_PSE | _PAGE_PRESENT)) == \
420 (_PAGE_PSE | _PAGE_PRESENT))
421
422/*
423 * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
424 *
425 * this macro returns the index of the entry in the pgd page which would
426 * control the given virtual address
427 */
428#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
429
430/*
431 * pgd_offset() returns a (pgd_t *)
432 * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
433 */
434#define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
435
436/*
437 * a shortcut which implies the use of the kernel's pgd, instead
438 * of a process's
439 */
440#define pgd_offset_k(address) pgd_offset(&init_mm, address)
441
442/*
443 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
444 *
445 * this macro returns the index of the entry in the pmd page which would
446 * control the given virtual address
447 */
448#define pmd_index(address) \
449 (((address) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
450
451/*
452 * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
453 *
454 * this macro returns the index of the entry in the pte page which would
455 * control the given virtual address
456 */
457#define pte_index(address) \
458 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
459
460#define pte_offset_kernel(dir, address) \
461 ((pte_t *) pmd_page_kernel(*(dir)) + pte_index(address))
462
463/*
464 * Make a given kernel text page executable/non-executable.
465 * Returns the previous executability setting of that page (which
466 * is used to restore the previous state). Used by the SMP bootup code.
467 * NOTE: this is an __init function for security reasons.
468 */
469static inline int set_kernel_exec(unsigned long vaddr, int enable)
470{
471 return 0;
472}
473
474#define pte_offset_map(dir, address) \
475 ((pte_t *) page_address(pmd_page(*(dir))) + pte_index(address))
476#define pte_unmap(pte) do {} while (0)
477
478/*
479 * The MN10300 has external MMU info in the form of a TLB: this is adapted from
480 * the kernel page tables containing the necessary information by tlb-mn10300.S
481 */
482extern void update_mmu_cache(struct vm_area_struct *vma,
483 unsigned long address, pte_t *ptep);
484
485#endif /* !__ASSEMBLY__ */
486
487#define kern_addr_valid(addr) (1)
488
489#define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \
490 remap_pfn_range((vma), (vaddr), (pfn), (size), (prot))
491
492#define MK_IOSPACE_PFN(space, pfn) (pfn)
493#define GET_IOSPACE(pfn) 0
494#define GET_PFN(pfn) (pfn)
495
496#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
497#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
498#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
499#define __HAVE_ARCH_PTEP_SET_WRPROTECT
500#define __HAVE_ARCH_PTEP_MKDIRTY
501#define __HAVE_ARCH_PTE_SAME
502#include <asm-generic/pgtable.h>
503
504#endif /* !__ASSEMBLY__ */
505
506#endif /* _ASM_PGTABLE_H */