projects/linux·blob master · refs

286 lines · 7.7 KiB

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_XPA)
36
37/*
38 * Page table bit offsets used for 64 bit physical addressing on
39 * MIPS32r5 with XPA.
40 */
41enum pgtable_bits {
42 /* Used by TLB hardware (placed in EntryLo*) */
43 _PAGE_NO_EXEC_SHIFT,
44 _PAGE_NO_READ_SHIFT,
45 _PAGE_GLOBAL_SHIFT,
46 _PAGE_VALID_SHIFT,
47 _PAGE_DIRTY_SHIFT,
48 _CACHE_SHIFT,
49
50 /* Used only by software (masked out before writing EntryLo*) */
51 _PAGE_PRESENT_SHIFT = 24,
52 _PAGE_WRITE_SHIFT,
53 _PAGE_ACCESSED_SHIFT,
54 _PAGE_MODIFIED_SHIFT,
55#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
56 _PAGE_SPECIAL_SHIFT,
57#endif
58#if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY)
59 _PAGE_SOFT_DIRTY_SHIFT,
60#endif
61};
62
63/*
64 * Bits for extended EntryLo0/EntryLo1 registers
65 */
66#define _PFNX_MASK 0xffffff
67
68#elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
69
70/*
71 * Page table bit offsets used for 36 bit physical addressing on MIPS32,
72 * for example with Alchemy or Netlogic XLP/XLR.
73 */
74enum pgtable_bits {
75 /* Used by TLB hardware (placed in EntryLo*) */
76 _PAGE_GLOBAL_SHIFT,
77 _PAGE_VALID_SHIFT,
78 _PAGE_DIRTY_SHIFT,
79 _CACHE_SHIFT,
80
81 /* Used only by software (masked out before writing EntryLo*) */
82 _PAGE_PRESENT_SHIFT = _CACHE_SHIFT + 3,
83 _PAGE_NO_READ_SHIFT,
84 _PAGE_WRITE_SHIFT,
85 _PAGE_ACCESSED_SHIFT,
86 _PAGE_MODIFIED_SHIFT,
87#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
88 _PAGE_SPECIAL_SHIFT,
89#endif
90#if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY)
91 _PAGE_SOFT_DIRTY_SHIFT,
92#endif
93};
94
95#elif defined(CONFIG_CPU_R3K_TLB)
96
97/* Page table bits used for r3k systems */
98enum pgtable_bits {
99 /* Used only by software (writes to EntryLo ignored) */
100 _PAGE_PRESENT_SHIFT,
101 _PAGE_NO_READ_SHIFT,
102 _PAGE_WRITE_SHIFT,
103 _PAGE_ACCESSED_SHIFT,
104 _PAGE_MODIFIED_SHIFT,
105#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
106 _PAGE_SPECIAL_SHIFT,
107#endif
108#if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY)
109 _PAGE_SOFT_DIRTY_SHIFT,
110#endif
111
112 /* Used by TLB hardware (placed in EntryLo) */
113 _PAGE_GLOBAL_SHIFT = 8,
114 _PAGE_VALID_SHIFT,
115 _PAGE_DIRTY_SHIFT,
116 _CACHE_UNCACHED_SHIFT,
117};
118
119#else
120
121/* Page table bits used for r4k systems */
122enum pgtable_bits {
123 /* Used only by software (masked out before writing EntryLo*) */
124 _PAGE_PRESENT_SHIFT,
125#if !defined(CONFIG_CPU_HAS_RIXI)
126 _PAGE_NO_READ_SHIFT,
127#endif
128 _PAGE_WRITE_SHIFT,
129 _PAGE_ACCESSED_SHIFT,
130 _PAGE_MODIFIED_SHIFT,
131#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT)
132 _PAGE_HUGE_SHIFT,
133#endif
134#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
135 _PAGE_SPECIAL_SHIFT,
136#endif
137#if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY)
138 _PAGE_SOFT_DIRTY_SHIFT,
139#endif
140 /* Used by TLB hardware (placed in EntryLo*) */
141#if defined(CONFIG_CPU_HAS_RIXI)
142 _PAGE_NO_EXEC_SHIFT,
143 _PAGE_NO_READ_SHIFT,
144#endif
145 _PAGE_GLOBAL_SHIFT,
146 _PAGE_VALID_SHIFT,
147 _PAGE_DIRTY_SHIFT,
148 _CACHE_SHIFT,
149};
150
151#endif /* defined(CONFIG_PHYS_ADDR_T_64BIT && defined(CONFIG_CPU_MIPS32) */
152
153/* Used only by software */
154#define _PAGE_PRESENT (1 << _PAGE_PRESENT_SHIFT)
155#define _PAGE_WRITE (1 << _PAGE_WRITE_SHIFT)
156#define _PAGE_ACCESSED (1 << _PAGE_ACCESSED_SHIFT)
157#define _PAGE_MODIFIED (1 << _PAGE_MODIFIED_SHIFT)
158#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT)
159# define _PAGE_HUGE (1 << _PAGE_HUGE_SHIFT)
160#endif
161#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
162# define _PAGE_SPECIAL (1 << _PAGE_SPECIAL_SHIFT)
163#else
164# define _PAGE_SPECIAL 0
165#endif
166#if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY)
167# define _PAGE_SOFT_DIRTY (1 << _PAGE_SOFT_DIRTY_SHIFT)
168#else
169# define _PAGE_SOFT_DIRTY 0
170#endif
171
172/* Used by TLB hardware (placed in EntryLo*) */
173#if defined(CONFIG_XPA)
174# define _PAGE_NO_EXEC (1 << _PAGE_NO_EXEC_SHIFT)
175#elif defined(CONFIG_CPU_HAS_RIXI)
176# define _PAGE_NO_EXEC (cpu_has_rixi ? (1 << _PAGE_NO_EXEC_SHIFT) : 0)
177#endif
178#define _PAGE_NO_READ (1 << _PAGE_NO_READ_SHIFT)
179#define _PAGE_GLOBAL (1 << _PAGE_GLOBAL_SHIFT)
180#define _PAGE_VALID (1 << _PAGE_VALID_SHIFT)
181#define _PAGE_DIRTY (1 << _PAGE_DIRTY_SHIFT)
182#if defined(CONFIG_CPU_R3K_TLB)
183# define _CACHE_UNCACHED (1 << _CACHE_UNCACHED_SHIFT)
184# define _CACHE_MASK _CACHE_UNCACHED
185# define PFN_PTE_SHIFT PAGE_SHIFT
186#else
187# define _CACHE_MASK (7 << _CACHE_SHIFT)
188# define PFN_PTE_SHIFT (PAGE_SHIFT - 12 + _CACHE_SHIFT + 3)
189#endif
190
191#ifndef _PAGE_NO_EXEC
192#define _PAGE_NO_EXEC 0
193#endif
194
195#define _PAGE_SILENT_READ _PAGE_VALID
196#define _PAGE_SILENT_WRITE _PAGE_DIRTY
197
198#define _PFN_MASK (~((1 << (PFN_PTE_SHIFT)) - 1))
199
200/*
201 * The final layouts of the PTE bits are:
202 *
203 * 64-bit, R1 or earlier: CCC D V G [S H] M A W R P
204 * 32-bit, R1 or earlier: CCC D V G M A W R P
205 * 64-bit, R2 or later: CCC D V G RI/R XI [S H] M A W P
206 * 32-bit, R2 or later: CCC D V G RI/R XI M A W P
207 */
208
209
210/*
211 * pte_to_entrylo converts a page table entry (PTE) into a Mips
212 * entrylo0/1 value.
213 */
214static inline uint64_t pte_to_entrylo(unsigned long pte_val)
215{
216#ifdef CONFIG_CPU_HAS_RIXI
217 if (cpu_has_rixi) {
218 int sa;
219#ifdef CONFIG_32BIT
220 sa = 31 - _PAGE_NO_READ_SHIFT;
221#else
222 sa = 63 - _PAGE_NO_READ_SHIFT;
223#endif
224 /*
225 * C has no way to express that this is a DSRL
226 * _PAGE_NO_EXEC_SHIFT followed by a ROTR 2. Luckily
227 * in the fast path this is done in assembly
228 */
229 return (pte_val >> _PAGE_GLOBAL_SHIFT) |
230 ((pte_val & (_PAGE_NO_EXEC | _PAGE_NO_READ)) << sa);
231 }
232#endif
233
234 return pte_val >> _PAGE_GLOBAL_SHIFT;
235}
236
237/*
238 * Cache attributes
239 */
240#if defined(CONFIG_CPU_R3K_TLB)
241
242#define _CACHE_CACHABLE_NONCOHERENT 0
243#define _CACHE_UNCACHED_ACCELERATED _CACHE_UNCACHED
244
245#elif defined(CONFIG_CPU_SB1)
246
247/* No penalty for being coherent on the SB1, so just
248 use it for "noncoherent" spaces, too. Shouldn't hurt. */
249
250#define _CACHE_CACHABLE_NONCOHERENT (5<<_CACHE_SHIFT)
251
252#endif
253
254#ifndef _CACHE_CACHABLE_NO_WA
255#define _CACHE_CACHABLE_NO_WA (0<<_CACHE_SHIFT)
256#endif
257#ifndef _CACHE_CACHABLE_WA
258#define _CACHE_CACHABLE_WA (1<<_CACHE_SHIFT)
259#endif
260#ifndef _CACHE_UNCACHED
261#define _CACHE_UNCACHED (2<<_CACHE_SHIFT)
262#endif
263#ifndef _CACHE_CACHABLE_NONCOHERENT
264#define _CACHE_CACHABLE_NONCOHERENT (3<<_CACHE_SHIFT)
265#endif
266#ifndef _CACHE_CACHABLE_CE
267#define _CACHE_CACHABLE_CE (4<<_CACHE_SHIFT)
268#endif
269#ifndef _CACHE_CACHABLE_COW
270#define _CACHE_CACHABLE_COW (5<<_CACHE_SHIFT)
271#endif
272#ifndef _CACHE_CACHABLE_CUW
273#define _CACHE_CACHABLE_CUW (6<<_CACHE_SHIFT)
274#endif
275#ifndef _CACHE_UNCACHED_ACCELERATED
276#define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT)
277#endif
278
279#define __READABLE (_PAGE_SILENT_READ | _PAGE_ACCESSED)
280#define __WRITEABLE (_PAGE_SILENT_WRITE | _PAGE_WRITE | _PAGE_MODIFIED)
281
282#define _PAGE_CHG_MASK (_PAGE_ACCESSED | _PAGE_MODIFIED | \
283 _PAGE_SOFT_DIRTY | _PFN_MASK | \
284 _CACHE_MASK | _PAGE_SPECIAL)
285
286#endif /* _ASM_PGTABLE_BITS_H */