summaryrefslogtreecommitdiffstats
path: root/arch/openrisc/include/asm/pgtable.h
blob: 37bf6a3ef8f4f561e52bff3d96d6bd43ba6c5dd8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
/*
 * OpenRISC Linux
 *
 * Linux architectural port borrowing liberally from similar works of
 * others.  All original copyrights apply as per the original source
 * declaration.
 *
 * OpenRISC implementation:
 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
 * et al.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

/* or32 pgtable.h - macros and functions to manipulate page tables
 *
 * Based on:
 * include/asm-cris/pgtable.h
 */

#ifndef __ASM_OPENRISC_PGTABLE_H
#define __ASM_OPENRISC_PGTABLE_H

#include <asm-generic/pgtable-nopmd.h>

#ifndef __ASSEMBLY__
#include <asm/mmu.h>
#include <asm/fixmap.h>

/*
 * The Linux memory management assumes a three-level page table setup. On
 * or32, we use that, but "fold" the mid level into the top-level page
 * table. Since the MMU TLB is software loaded through an interrupt, it
 * supports any page table structure, so we could have used a three-level
 * setup, but for the amounts of memory we normally use, a two-level is
 * probably more efficient.
 *
 * This file contains the functions and defines necessary to modify and use
 * the or32 page table tree.
 */

extern void paging_init(void);

/* Certain architectures need to do special things when pte's
 * within a page table are directly modified.  Thus, the following
 * hook is made available.
 */
#define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval))
#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
/*
 * (pmds are folded into pgds so this doesn't get actually called,
 * but the define is needed for a generic inline function.)
 */
#define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)

#define PGDIR_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT-2))
#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
#define PGDIR_MASK	(~(PGDIR_SIZE-1))

/*
 * entries per page directory level: we use a two-level, so
 * we don't really have any PMD directory physically.
 * pointers are 4 bytes so we can use the page size and
 * divide it by 4 (shift by 2).
 */
#define PTRS_PER_PTE	(1UL << (PAGE_SHIFT-2))

#define PTRS_PER_PGD	(1UL << (PAGE_SHIFT-2))

/* calculate how many PGD entries a user-level program can use
 * the first mappable virtual address is 0
 * (TASK_SIZE is the maximum virtual address space)
 */

#define USER_PTRS_PER_PGD       (TASK_SIZE/PGDIR_SIZE)
#define FIRST_USER_ADDRESS      0

/*
 * Kernels own virtual memory area.
 */

/*
 * The size and location of the vmalloc area are chosen so that modules
 * placed in this area aren't more than a 28-bit signed offset from any
 * kernel functions that they may need.  This greatly simplifies handling
 * of the relocations for l.j and l.jal instructions as we don't need to
 * introduce any trampolines for reaching "distant" code.
 *
 * 64 MB of vmalloc area is comparable to what's available on other arches.
 */

#define VMALLOC_START	(PAGE_OFFSET-0x04000000)
#define VMALLOC_END	(PAGE_OFFSET)
#define VMALLOC_VMADDR(x) ((unsigned long)(x))

/* Define some higher level generic page attributes.
 *
 * If you change _PAGE_CI definition be sure to change it in
 * io.h for ioremap_nocache() too.
 */

/*
 * An OR32 PTE looks like this:
 *
 * |  31 ... 10 |  9  |  8 ... 6  |  5  |  4  |  3  |  2  |  1  |  0  |
 *  Phys pg.num    L     PP Index    D     A    WOM   WBC   CI    CC
 *
 *  L  : link
 *  PPI: Page protection index
 *  D  : Dirty
 *  A  : Accessed
 *  WOM: Weakly ordered memory
 *  WBC: Write-back cache
 *  CI : Cache inhibit
 *  CC : Cache coherent
 *
 * The protection bits below should correspond to the layout of the actual
 * PTE as per above
 */

#define _PAGE_CC       0x001 /* software: pte contains a translation */
#define _PAGE_CI       0x002 /* cache inhibit          */
#define _PAGE_WBC      0x004 /* write back cache       */
#define _PAGE_FILE     0x004 /* set: pagecache, unset: swap (when !PRESENT) */
#define _PAGE_WOM      0x008 /* weakly ordered memory  */

#define _PAGE_A        0x010 /* accessed               */
#define _PAGE_D        0x020 /* dirty                  */
#define _PAGE_URE      0x040 /* user read enable       */
#define _PAGE_UWE      0x080 /* user write enable      */

#define _PAGE_SRE      0x100 /* superuser read enable  */
#define _PAGE_SWE      0x200 /* superuser write enable */
#define _PAGE_EXEC     0x400 /* software: page is executable */
#define _PAGE_U_SHARED 0x800 /* software: page is shared in user space */

/* 0x001 is cache coherency bit, which should always be set to
 *       1 - for SMP (when we support it)
 *       0 - otherwise
 *
 * we just reuse this bit in software for _PAGE_PRESENT and
 * force it to 0 when loading it into TLB.
 */
#define _PAGE_PRESENT  _PAGE_CC
#define _PAGE_USER     _PAGE_URE
#define _PAGE_WRITE    (_PAGE_UWE | _PAGE_SWE)
#define _PAGE_DIRTY    _PAGE_D
#define _PAGE_ACCESSED _PAGE_A
#define _PAGE_NO_CACHE _PAGE_CI
#define _PAGE_SHARED   _PAGE_U_SHARED
#define _PAGE_READ     (_PAGE_URE | _PAGE_SRE)

#define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
#define _PAGE_BASE     (_PAGE_PRESENT | _PAGE_ACCESSED)
#define _PAGE_ALL      (_PAGE_PRESENT | _PAGE_ACCESSED)
#define _KERNPG_TABLE \
	(_PAGE_BASE | _PAGE_SRE | _PAGE_SWE | _PAGE_ACCESSED | _PAGE_DIRTY)

#define PAGE_NONE       __pgprot(_PAGE_ALL)
#define PAGE_READONLY   __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE)
#define PAGE_READONLY_X __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_EXEC)
#define PAGE_SHARED \
	__pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_UWE | _PAGE_SWE \
		 | _PAGE_SHARED)
#define PAGE_SHARED_X \
	__pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_UWE | _PAGE_SWE \
		 | _PAGE_SHARED | _PAGE_EXEC)
#define PAGE_COPY       __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE)
#define PAGE_COPY_X     __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_EXEC)

#define PAGE_KERNEL \
	__pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \
		 | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC)
#define PAGE_KERNEL_RO \
	__pgprot(_PAGE_ALL | _PAGE_SRE \
		 | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC)
#define PAGE_KERNEL_NOCACHE \
	__pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \
		 | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC | _PAGE_CI)

#define __P000	PAGE_NONE
#define __P001	PAGE_READONLY_X
#define __P010	PAGE_COPY
#define __P011	PAGE_COPY_X
#define __P100	PAGE_READONLY
#define __P101	PAGE_READONLY_X
#define __P110	PAGE_COPY
#define __P111	PAGE_COPY_X

#define __S000	PAGE_NONE
#define __S001	PAGE_READONLY_X
#define __S010	PAGE_SHARED
#define __S011	PAGE_SHARED_X
#define __S100	PAGE_READONLY
#define __S101	PAGE_READONLY_X
#define __S110	PAGE_SHARED
#define __S111	PAGE_SHARED_X

/* zero page used for uninitialized stuff */
extern unsigned long empty_zero_page[2048];
#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))

/* number of bits that fit into a memory pointer */
#define BITS_PER_PTR			(8*sizeof(unsigned long))

/* to align the pointer to a pointer address */
#define PTR_MASK			(~(sizeof(void *)-1))

/* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
/* 64-bit machines, beware!  SRB. */
#define SIZEOF_PTR_LOG2			2

/* to find an entry in a page-table */
#define PAGE_PTR(address) \
((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK)

/* to set the page-dir */
#define SET_PAGE_DIR(tsk, pgdir)

#define pte_none(x)	(!pte_val(x))
#define pte_present(x)	(pte_val(x) & _PAGE_PRESENT)
#define pte_clear(mm, addr, xp)	do { pte_val(*(xp)) = 0; } while (0)

#define pmd_none(x)	(!pmd_val(x))
#define	pmd_bad(x)	((pmd_val(x) & (~PAGE_MASK)) != _KERNPG_TABLE)
#define pmd_present(x)	(pmd_val(x) & _PAGE_PRESENT)
#define pmd_clear(xp)	do { pmd_val(*(xp)) = 0; } while (0)

/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */

static inline int pte_read(pte_t pte)  { return pte_val(pte) & _PAGE_READ; }
static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; }
static inline int pte_exec(pte_t pte)  { return pte_val(pte) & _PAGE_EXEC; }
static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
static inline int pte_file(pte_t pte)  { return pte_val(pte) & _PAGE_FILE; }
static inline int pte_special(pte_t pte) { return 0; }
static inline pte_t pte_mkspecial(pte_t pte) { return pte; }

static inline pte_t pte_wrprotect(pte_t pte)
{
	pte_val(pte) &= ~(_PAGE_WRITE);
	return pte;
}

static inline pte_t pte_rdprotect(pte_t pte)
{
	pte_val(pte) &= ~(_PAGE_READ);
	return pte;
}

static inline pte_t pte_exprotect(pte_t pte)
{
	pte_val(pte) &= ~(_PAGE_EXEC);
	return pte;
}

static inline pte_t pte_mkclean(pte_t pte)
{
	pte_val(pte) &= ~(_PAGE_DIRTY);
	return pte;
}

static inline pte_t pte_mkold(pte_t pte)
{
	pte_val(pte) &= ~(_PAGE_ACCESSED);
	return pte;
}

static inline pte_t pte_mkwrite(pte_t pte)
{
	pte_val(pte) |= _PAGE_WRITE;
	return pte;
}

static inline pte_t pte_mkread(pte_t pte)
{
	pte_val(pte) |= _PAGE_READ;
	return pte;
}

static inline pte_t pte_mkexec(pte_t pte)
{
	pte_val(pte) |= _PAGE_EXEC;
	return pte;
}

static inline pte_t pte_mkdirty(pte_t pte)
{
	pte_val(pte) |= _PAGE_DIRTY;
	return pte;
}

static inline pte_t pte_mkyoung(pte_t pte)
{
	pte_val(pte) |= _PAGE_ACCESSED;
	return pte;
}

/*
 * Conversion functions: convert a page and protection to a page entry,
 * and a page entry and page directory to the page they refer to.
 */

/* What actually goes as arguments to the various functions is less than
 * obvious, but a rule of thumb is that struct page's goes as struct page *,
 * really physical DRAM addresses are unsigned long's, and DRAM "virtual"
 * addresses (the 0xc0xxxxxx's) goes as void *'s.
 */

static inline pte_t __mk_pte(void *page, pgprot_t pgprot)
{
	pte_t pte;
	/* the PTE needs a physical address */
	pte_val(pte) = __pa(page) | pgprot_val(pgprot);
	return pte;
}

#define mk_pte(page, pgprot) __mk_pte(page_address(page), (pgprot))

#define mk_pte_phys(physpage, pgprot) \
({                                                                      \
	pte_t __pte;                                                    \
									\
	pte_val(__pte) = (physpage) + pgprot_val(pgprot);               \
	__pte;                                                          \
})

static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
	pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot);
	return pte;
}


/*
 * pte_val refers to a page in the 0x0xxxxxxx physical DRAM interval
 * __pte_page(pte_val) refers to the "virtual" DRAM interval
 * pte_pagenr refers to the page-number counted starting from the virtual
 * DRAM start
 */

static inline unsigned long __pte_page(pte_t pte)
{
	/* the PTE contains a physical address */
	return (unsigned long)__va(pte_val(pte) & PAGE_MASK);
}

#define pte_pagenr(pte)         ((__pte_page(pte) - PAGE_OFFSET) >> PAGE_SHIFT)

/* permanent address of a page */

#define __page_address(page) (PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT))
#define pte_page(pte)		(mem_map+pte_pagenr(pte))

/*
 * only the pte's themselves need to point to physical DRAM (see above)
 * the pagetable links are purely handled within the kernel SW and thus
 * don't need the __pa and __va transformations.
 */
static inline void pmd_set(pmd_t *pmdp, pte_t *ptep)
{
	pmd_val(*pmdp) = _KERNPG_TABLE | (unsigned long) ptep;
}

#define pmd_page(pmd)		(pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
#define pmd_page_kernel(pmd)    ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))

/* to find an entry in a page-table-directory. */
#define pgd_index(address)      ((address >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))

#define __pgd_offset(address)   pgd_index(address)

#define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))

/* to find an entry in a kernel page-table-directory */
#define pgd_offset_k(address) pgd_offset(&init_mm, address)

#define __pmd_offset(address) \
	(((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))

/*
 * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
 *
 * this macro returns the index of the entry in the pte page which would
 * control the given virtual address
 */
#define __pte_offset(address)                   \
	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
#define pte_offset_kernel(dir, address)         \
	((pte_t *) pmd_page_kernel(*(dir)) +  __pte_offset(address))
#define pte_offset_map(dir, address)	        \
	((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
#define pte_offset_map_nested(dir, address)     \
	pte_offset_map(dir, address)

#define pte_unmap(pte)          do { } while (0)
#define pte_unmap_nested(pte)   do { } while (0)
#define pte_pfn(x)		((unsigned long)(((x).pte)) >> PAGE_SHIFT)
#define pfn_pte(pfn, prot)  __pte((((pfn) << PAGE_SHIFT)) | pgprot_val(prot))

#define pte_ERROR(e) \
	printk(KERN_ERR "%s:%d: bad pte %p(%08lx).\n", \
	       __FILE__, __LINE__, &(e), pte_val(e))
#define pgd_ERROR(e) \
	printk(KERN_ERR "%s:%d: bad pgd %p(%08lx).\n", \
	       __FILE__, __LINE__, &(e), pgd_val(e))

extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* defined in head.S */

/*
 * or32 doesn't have any external MMU info: the kernel page
 * tables contain all the necessary information.
 *
 * Actually I am not sure on what this could be used for.
 */
static inline void update_mmu_cache(struct vm_area_struct *vma,
	unsigned long address, pte_t *pte)
{
}

/* __PHX__ FIXME, SWAP, this probably doesn't work */

/* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */
/* Since the PAGE_PRESENT bit is bit 4, we can use the bits above */

#define __swp_type(x)			(((x).val >> 5) & 0x7f)
#define __swp_offset(x)			((x).val >> 12)
#define __swp_entry(type, offset) \
	((swp_entry_t) { ((type) << 5) | ((offset) << 12) })
#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(x)		((pte_t) { (x).val })

/* Encode and decode a nonlinear file mapping entry */

#define PTE_FILE_MAX_BITS               26
#define pte_to_pgoff(x)	                (pte_val(x) >> 6)
#define pgoff_to_pte(x)	                __pte(((x) << 6) | _PAGE_FILE)

#define kern_addr_valid(addr)           (1)

#include <asm-generic/pgtable.h>

/*
 * No page table caches to initialise
 */
#define pgtable_cache_init()		do { } while (0)

typedef pte_t *pte_addr_t;

#endif /* __ASSEMBLY__ */
#endif /* __ASM_OPENRISC_PGTABLE_H */