summaryrefslogtreecommitdiff
path: root/arch/mips/include/asm/pgtable-bits.h
blob: e9fe7e97ce4cbf23f9bb198a9c351b92005346f7 (plain) (blame)
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
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1994 - 2002 by Ralf Baechle
 * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
 * Copyright (C) 2002  Maciej W. Rozycki
 */
#ifndef _ASM_PGTABLE_BITS_H
#define _ASM_PGTABLE_BITS_H


/*
 * Note that we shift the lower 32bits of each EntryLo[01] entry
 * 6 bits to the left. That way we can convert the PFN into the
 * physical address by a single 'and' operation and gain 6 additional
 * bits for storing information which isn't present in a normal
 * MIPS page table.
 *
 * Similar to the Alpha port, we need to keep track of the ref
 * and mod bits in software.  We have a software "yeah you can read
 * from this page" bit, and a hardware one which actually lets the
 * process read from the page.  On the same token we have a software
 * writable bit and the real hardware one which actually lets the
 * process write to the page, this keeps a mod bit via the hardware
 * dirty bit.
 *
 * Certain revisions of the R4000 and R5000 have a bug where if a
 * certain sequence occurs in the last 3 instructions of an executable
 * page, and the following page is not mapped, the cpu can do
 * unpredictable things.  The code (when it is written) to deal with
 * this problem will be in the update_mmu_cache() code for the r4k.
 */
#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)

#define _PAGE_PRESENT               (1<<6)  /* implemented in software */
#define _PAGE_READ                  (1<<7)  /* implemented in software */
#define _PAGE_WRITE                 (1<<8)  /* implemented in software */
#define _PAGE_ACCESSED              (1<<9)  /* implemented in software */
#define _PAGE_MODIFIED              (1<<10) /* implemented in software */
#define _PAGE_FILE                  (1<<10) /* set:pagecache unset:swap */

#define _PAGE_R4KBUG                (1<<0)  /* workaround for r4k bug  */
#define _PAGE_GLOBAL                (1<<0)
#define _PAGE_VALID                 (1<<1)
#define _PAGE_SILENT_READ           (1<<1)  /* synonym                 */
#define _PAGE_DIRTY                 (1<<2)  /* The MIPS dirty bit      */
#define _PAGE_SILENT_WRITE          (1<<2)
#define _CACHE_SHIFT                3
#define _CACHE_MASK                 (7<<3)

#elif defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)

#define _PAGE_PRESENT               (1<<0)  /* implemented in software */
#define _PAGE_READ                  (1<<1)  /* implemented in software */
#define _PAGE_WRITE                 (1<<2)  /* implemented in software */
#define _PAGE_ACCESSED              (1<<3)  /* implemented in software */
#define _PAGE_MODIFIED              (1<<4)  /* implemented in software */
#define _PAGE_FILE                  (1<<4)  /* set:pagecache unset:swap */

#define _PAGE_GLOBAL                (1<<8)
#define _PAGE_VALID                 (1<<9)
#define _PAGE_SILENT_READ           (1<<9)  /* synonym                 */
#define _PAGE_DIRTY                 (1<<10) /* The MIPS dirty bit      */
#define _PAGE_SILENT_WRITE          (1<<10)
#define _CACHE_UNCACHED             (1<<11)
#define _CACHE_MASK                 (1<<11)

#else /* 'Normal' r4K case */
/*
 * When using the RI/XI bit support, we have 13 bits of flags below
 * the physical address. The RI/XI bits are placed such that a SRL 5
 * can strip off the software bits, then a ROTR 2 can move the RI/XI
 * into bits [63:62]. This also limits physical address to 56 bits,
 * which is more than we need right now.
 */

/* implemented in software */
#define _PAGE_PRESENT_SHIFT	(0)
#define _PAGE_PRESENT		(1 << _PAGE_PRESENT_SHIFT)
/* implemented in software, should be unused if kernel_uses_smartmips_rixi. */
#define _PAGE_READ_SHIFT	(kernel_uses_smartmips_rixi ? _PAGE_PRESENT_SHIFT : _PAGE_PRESENT_SHIFT + 1)
#define _PAGE_READ ({if (kernel_uses_smartmips_rixi) BUG(); 1 << _PAGE_READ_SHIFT; })
/* implemented in software */
#define _PAGE_WRITE_SHIFT	(_PAGE_READ_SHIFT + 1)
#define _PAGE_WRITE		(1 << _PAGE_WRITE_SHIFT)
/* implemented in software */
#define _PAGE_ACCESSED_SHIFT	(_PAGE_WRITE_SHIFT + 1)
#define _PAGE_ACCESSED		(1 << _PAGE_ACCESSED_SHIFT)
/* implemented in software */
#define _PAGE_MODIFIED_SHIFT	(_PAGE_ACCESSED_SHIFT + 1)
#define _PAGE_MODIFIED		(1 << _PAGE_MODIFIED_SHIFT)
/* set:pagecache unset:swap */
#define _PAGE_FILE		(_PAGE_MODIFIED)

#ifdef CONFIG_HUGETLB_PAGE
/* huge tlb page */
#define _PAGE_HUGE_SHIFT	(_PAGE_MODIFIED_SHIFT + 1)
#define _PAGE_HUGE		(1 << _PAGE_HUGE_SHIFT)
#else
#define _PAGE_HUGE_SHIFT	(_PAGE_MODIFIED_SHIFT)
#define _PAGE_HUGE		({BUG(); 1; })  /* Dummy value */
#endif

/* Page cannot be executed */
#define _PAGE_NO_EXEC_SHIFT	(kernel_uses_smartmips_rixi ? _PAGE_HUGE_SHIFT + 1 : _PAGE_HUGE_SHIFT)
#define _PAGE_NO_EXEC		({if (!kernel_uses_smartmips_rixi) BUG(); 1 << _PAGE_NO_EXEC_SHIFT; })

/* Page cannot be read */
#define _PAGE_NO_READ_SHIFT	(kernel_uses_smartmips_rixi ? _PAGE_NO_EXEC_SHIFT + 1 : _PAGE_NO_EXEC_SHIFT)
#define _PAGE_NO_READ		({if (!kernel_uses_smartmips_rixi) BUG(); 1 << _PAGE_NO_READ_SHIFT; })

#define _PAGE_GLOBAL_SHIFT	(_PAGE_NO_READ_SHIFT + 1)
#define _PAGE_GLOBAL		(1 << _PAGE_GLOBAL_SHIFT)

#define _PAGE_VALID_SHIFT	(_PAGE_GLOBAL_SHIFT + 1)
#define _PAGE_VALID		(1 << _PAGE_VALID_SHIFT)
/* synonym                 */
#define _PAGE_SILENT_READ	(_PAGE_VALID)

/* The MIPS dirty bit      */
#define _PAGE_DIRTY_SHIFT	(_PAGE_VALID_SHIFT + 1)
#define _PAGE_DIRTY		(1 << _PAGE_DIRTY_SHIFT)
#define _PAGE_SILENT_WRITE	(_PAGE_DIRTY)

#define _CACHE_SHIFT		(_PAGE_DIRTY_SHIFT + 1)
#define _CACHE_MASK		(7 << _CACHE_SHIFT)

#define _PFN_SHIFT		(PAGE_SHIFT - 12 + _CACHE_SHIFT + 3)

#endif /* defined(CONFIG_64BIT_PHYS_ADDR && defined(CONFIG_CPU_MIPS32) */

#ifndef _PFN_SHIFT
#define _PFN_SHIFT                  PAGE_SHIFT
#endif
#define _PFN_MASK		(~((1 << (_PFN_SHIFT)) - 1))

#ifndef _PAGE_NO_READ
#define _PAGE_NO_READ ({BUG(); 0; })
#define _PAGE_NO_READ_SHIFT ({BUG(); 0; })
#endif
#ifndef _PAGE_NO_EXEC
#define _PAGE_NO_EXEC ({BUG(); 0; })
#endif
#ifndef _PAGE_GLOBAL_SHIFT
#define _PAGE_GLOBAL_SHIFT ilog2(_PAGE_GLOBAL)
#endif


#ifndef __ASSEMBLY__
/*
 * pte_to_entrylo converts a page table entry (PTE) into a Mips
 * entrylo0/1 value.
 */
static inline uint64_t pte_to_entrylo(unsigned long pte_val)
{
	if (kernel_uses_smartmips_rixi) {
		int sa;
#ifdef CONFIG_32BIT
		sa = 31 - _PAGE_NO_READ_SHIFT;
#else
		sa = 63 - _PAGE_NO_READ_SHIFT;
#endif
		/*
		 * C has no way to express that this is a DSRL
		 * _PAGE_NO_EXEC_SHIFT followed by a ROTR 2.  Luckily
		 * in the fast path this is done in assembly
		 */
		return (pte_val >> _PAGE_GLOBAL_SHIFT) |
			((pte_val & (_PAGE_NO_EXEC | _PAGE_NO_READ)) << sa);
	}

	return pte_val >> _PAGE_GLOBAL_SHIFT;
}
#endif

/*
 * Cache attributes
 */
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)

#define _CACHE_CACHABLE_NONCOHERENT 0

#elif defined(CONFIG_CPU_SB1)

/* No penalty for being coherent on the SB1, so just
   use it for "noncoherent" spaces, too.  Shouldn't hurt. */

#define _CACHE_UNCACHED             (2<<_CACHE_SHIFT)
#define _CACHE_CACHABLE_COW         (5<<_CACHE_SHIFT)
#define _CACHE_CACHABLE_NONCOHERENT (5<<_CACHE_SHIFT)
#define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT)

#elif defined(CONFIG_CPU_RM9000)

#define _CACHE_WT		    (0<<_CACHE_SHIFT)
#define _CACHE_WTWA		    (1<<_CACHE_SHIFT)
#define _CACHE_UC_B		    (2<<_CACHE_SHIFT)
#define _CACHE_WB		    (3<<_CACHE_SHIFT)
#define _CACHE_CWBEA		    (4<<_CACHE_SHIFT)
#define _CACHE_CWB		    (5<<_CACHE_SHIFT)
#define _CACHE_UCNB		    (6<<_CACHE_SHIFT)
#define _CACHE_FPC		    (7<<_CACHE_SHIFT)

#define _CACHE_UNCACHED		    _CACHE_UC_B
#define _CACHE_CACHABLE_NONCOHERENT _CACHE_WB

#else

#define _CACHE_CACHABLE_NO_WA	    (0<<_CACHE_SHIFT)  /* R4600 only      */
#define _CACHE_CACHABLE_WA	    (1<<_CACHE_SHIFT)  /* R4600 only      */
#define _CACHE_UNCACHED             (2<<_CACHE_SHIFT)  /* R4[0246]00      */
#define _CACHE_CACHABLE_NONCOHERENT (3<<_CACHE_SHIFT)  /* R4[0246]00      */
#define _CACHE_CACHABLE_CE          (4<<_CACHE_SHIFT)  /* R4[04]00MC only */
#define _CACHE_CACHABLE_COW         (5<<_CACHE_SHIFT)  /* R4[04]00MC only */
#define _CACHE_CACHABLE_COHERENT    (5<<_CACHE_SHIFT)  /* MIPS32R2 CMP    */
#define _CACHE_CACHABLE_CUW         (6<<_CACHE_SHIFT)  /* R4[04]00MC only */
#define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT)  /* R10000 only     */

#endif

#define __READABLE	(_PAGE_SILENT_READ | _PAGE_ACCESSED | (kernel_uses_smartmips_rixi ? 0 : _PAGE_READ))
#define __WRITEABLE	(_PAGE_WRITE | _PAGE_SILENT_WRITE | _PAGE_MODIFIED)

#define _PAGE_CHG_MASK  (_PFN_MASK | _PAGE_ACCESSED | _PAGE_MODIFIED | _CACHE_MASK)

#endif /* _ASM_PGTABLE_BITS_H */