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1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1994 - 2002 by Ralf Baechle
7 * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
8 * Copyright (C) 2002 Maciej W. Rozycki
9 */
10#ifndef _ASM_PGTABLE_BITS_H
11#define _ASM_PGTABLE_BITS_H
12
13
14/*
15 * Note that we shift the lower 32bits of each EntryLo[01] entry
16 * 6 bits to the left. That way we can convert the PFN into the
17 * physical address by a single 'and' operation and gain 6 additional
18 * bits for storing information which isn't present in a normal
19 * MIPS page table.
20 *
21 * Similar to the Alpha port, we need to keep track of the ref
22 * and mod bits in software. We have a software "yeah you can read
23 * from this page" bit, and a hardware one which actually lets the
24 * process read from the page. On the same token we have a software
25 * writable bit and the real hardware one which actually lets the
26 * process write to the page, this keeps a mod bit via the hardware
27 * dirty bit.
28 *
29 * Certain revisions of the R4000 and R5000 have a bug where if a
30 * certain sequence occurs in the last 3 instructions of an executable
31 * page, and the following page is not mapped, the cpu can do
32 * unpredictable things. The code (when it is written) to deal with
33 * this problem will be in the update_mmu_cache() code for the r4k.
34 */
35#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
36
37#define _PAGE_PRESENT (1<<6) /* implemented in software */
38#define _PAGE_READ (1<<7) /* implemented in software */
39#define _PAGE_WRITE (1<<8) /* implemented in software */
40#define _PAGE_ACCESSED (1<<9) /* implemented in software */
41#define _PAGE_MODIFIED (1<<10) /* implemented in software */
42#define _PAGE_FILE (1<<10) /* set:pagecache unset:swap */
43
44#define _PAGE_R4KBUG (1<<0) /* workaround for r4k bug */
45#define _PAGE_GLOBAL (1<<0)
46#define _PAGE_VALID (1<<1)
47#define _PAGE_SILENT_READ (1<<1) /* synonym */
48#define _PAGE_DIRTY (1<<2) /* The MIPS dirty bit */
49#define _PAGE_SILENT_WRITE (1<<2)
50#define _CACHE_SHIFT 3
51#define _CACHE_MASK (7<<3)
52
53#else
54
55#define _PAGE_PRESENT (1<<0) /* implemented in software */
56#define _PAGE_READ (1<<1) /* implemented in software */
57#define _PAGE_WRITE (1<<2) /* implemented in software */
58#define _PAGE_ACCESSED (1<<3) /* implemented in software */
59#define _PAGE_MODIFIED (1<<4) /* implemented in software */
60#define _PAGE_FILE (1<<4) /* set:pagecache unset:swap */
61
62#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
63
64#define _PAGE_GLOBAL (1<<8)
65#define _PAGE_VALID (1<<9)
66#define _PAGE_SILENT_READ (1<<9) /* synonym */
67#define _PAGE_DIRTY (1<<10) /* The MIPS dirty bit */
68#define _PAGE_SILENT_WRITE (1<<10)
69#define _CACHE_UNCACHED (1<<11)
70#define _CACHE_MASK (1<<11)
71
72#else
73
74#define _PAGE_R4KBUG (1<<5) /* workaround for r4k bug */
75#define _PAGE_GLOBAL (1<<6)
76#define _PAGE_VALID (1<<7)
77#define _PAGE_SILENT_READ (1<<7) /* synonym */
78#define _PAGE_DIRTY (1<<8) /* The MIPS dirty bit */
79#define _PAGE_SILENT_WRITE (1<<8)
80#define _CACHE_SHIFT 9
81#define _CACHE_MASK (7<<9)
82
83#endif
84#endif /* defined(CONFIG_64BIT_PHYS_ADDR && defined(CONFIG_CPU_MIPS32) */
85
86
87/*
88 * Cache attributes
89 */
90#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
91
92#define _CACHE_CACHABLE_NONCOHERENT 0
93
94#elif defined(CONFIG_CPU_SB1)
95
96/* No penalty for being coherent on the SB1, so just
97 use it for "noncoherent" spaces, too. Shouldn't hurt. */
98
99#define _CACHE_UNCACHED (2<<_CACHE_SHIFT)
100#define _CACHE_CACHABLE_COW (5<<_CACHE_SHIFT)
101#define _CACHE_CACHABLE_NONCOHERENT (5<<_CACHE_SHIFT)
102#define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT)
103
104#elif defined(CONFIG_CPU_RM9000)
105
106#define _CACHE_WT (0<<_CACHE_SHIFT)
107#define _CACHE_WTWA (1<<_CACHE_SHIFT)
108#define _CACHE_UC_B (2<<_CACHE_SHIFT)
109#define _CACHE_WB (3<<_CACHE_SHIFT)
110#define _CACHE_CWBEA (4<<_CACHE_SHIFT)
111#define _CACHE_CWB (5<<_CACHE_SHIFT)
112#define _CACHE_UCNB (6<<_CACHE_SHIFT)
113#define _CACHE_FPC (7<<_CACHE_SHIFT)
114
115#define _CACHE_UNCACHED _CACHE_UC_B
116#define _CACHE_CACHABLE_NONCOHERENT _CACHE_WB
117
118#else
119
120#define _CACHE_CACHABLE_NO_WA (0<<_CACHE_SHIFT) /* R4600 only */
121#define _CACHE_CACHABLE_WA (1<<_CACHE_SHIFT) /* R4600 only */
122#define _CACHE_UNCACHED (2<<_CACHE_SHIFT) /* R4[0246]00 */
123#define _CACHE_CACHABLE_NONCOHERENT (3<<_CACHE_SHIFT) /* R4[0246]00 */
124#define _CACHE_CACHABLE_CE (4<<_CACHE_SHIFT) /* R4[04]00MC only */
125#define _CACHE_CACHABLE_COW (5<<_CACHE_SHIFT) /* R4[04]00MC only */
126#define _CACHE_CACHABLE_COHERENT (5<<_CACHE_SHIFT) /* MIPS32R2 CMP */
127#define _CACHE_CACHABLE_CUW (6<<_CACHE_SHIFT) /* R4[04]00MC only */
128#define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT) /* R10000 only */
129
130#endif
131
132#define __READABLE (_PAGE_READ | _PAGE_SILENT_READ | _PAGE_ACCESSED)
133#define __WRITEABLE (_PAGE_WRITE | _PAGE_SILENT_WRITE | _PAGE_MODIFIED)
134
135#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_MODIFIED | _CACHE_MASK)
136
137#endif /* _ASM_PGTABLE_BITS_H */