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1#ifndef _SPARC_VAC_OPS_H
2#define _SPARC_VAC_OPS_H
3
4/* vac-ops.h: Inline assembly routines to do operations on the Sparc
5 * VAC (virtual address cache) for the sun4c.
6 *
7 * Copyright (C) 1994, David S. Miller (davem@caip.rutgers.edu)
8 */
9
10#include <asm/sysen.h>
11#include <asm/contregs.h>
12#include <asm/asi.h>
13
14/* The SUN4C models have a virtually addressed write-through
15 * cache.
16 *
17 * The cache tags are directly accessible through an ASI and
18 * each have the form:
19 *
20 * ------------------------------------------------------------
21 * | MBZ | CONTEXT | WRITE | PRIV | VALID | MBZ | TagID | MBZ |
22 * ------------------------------------------------------------
23 * 31 25 24 22 21 20 19 18 16 15 2 1 0
24 *
25 * MBZ: These bits are either unused and/or reserved and should
26 * be written as zeroes.
27 *
28 * CONTEXT: Records the context to which this cache line belongs.
29 *
30 * WRITE: A copy of the writable bit from the mmu pte access bits.
31 *
32 * PRIV: A copy of the privileged bit from the pte access bits.
33 *
34 * VALID: If set, this line is valid, else invalid.
35 *
36 * TagID: Fourteen bits of tag ID.
37 *
38 * Every virtual address is seen by the cache like this:
39 *
40 * ----------------------------------------
41 * | RESV | TagID | LINE | BYTE-in-LINE |
42 * ----------------------------------------
43 * 31 30 29 16 15 4 3 0
44 *
45 * RESV: Unused/reserved.
46 *
47 * TagID: Used to match the Tag-ID in that vac tags.
48 *
49 * LINE: Which line within the cache
50 *
51 * BYTE-in-LINE: Which byte within the cache line.
52 */
53
54/* Sun4c VAC Tags */
55#define S4CVACTAG_CID 0x01c00000
56#define S4CVACTAG_W 0x00200000
57#define S4CVACTAG_P 0x00100000
58#define S4CVACTAG_V 0x00080000
59#define S4CVACTAG_TID 0x0000fffc
60
61/* Sun4c VAC Virtual Address */
62/* These aren't used, why bother? (Anton) */
63#if 0
64#define S4CVACVA_TID 0x3fff0000
65#define S4CVACVA_LINE 0x0000fff0
66#define S4CVACVA_BIL 0x0000000f
67#endif
68
69/* The indexing of cache lines creates a problem. Because the line
70 * field of a virtual address extends past the page offset within
71 * the virtual address it is possible to have what are called
72 * 'bad aliases' which will create inconsistencies. So we must make
73 * sure that within a context that if a physical page is mapped
74 * more than once, that 'extra' line bits are the same. If this is
75 * not the case, and thus is a 'bad alias' we must turn off the
76 * cacheable bit in the pte's of all such pages.
77 */
78
79#ifdef CONFIG_SUN4
80#define S4CVAC_BADBITS 0x0001e000
81#else
82#define S4CVAC_BADBITS 0x0000f000
83#endif
84
85/* The following is true if vaddr1 and vaddr2 would cause
86 * a 'bad alias'.
87 */
88#define S4CVAC_BADALIAS(vaddr1, vaddr2) \
89 ((((unsigned long) (vaddr1)) ^ ((unsigned long) (vaddr2))) & \
90 (S4CVAC_BADBITS))
91
92/* The following structure describes the characteristics of a sun4c
93 * VAC as probed from the prom during boot time.
94 */
95struct sun4c_vac_props {
96 unsigned int num_bytes; /* Size of the cache */
97 unsigned int num_lines; /* Number of cache lines */
98 unsigned int do_hwflushes; /* Hardware flushing available? */
99 enum { VAC_NONE, VAC_WRITE_THROUGH,
100 VAC_WRITE_BACK } type; /* What type of VAC? */
101 unsigned int linesize; /* Size of each line in bytes */
102 unsigned int log2lsize; /* log2(linesize) */
103 unsigned int on; /* VAC is enabled */
104};
105
106extern struct sun4c_vac_props sun4c_vacinfo;
107
108/* sun4c_enable_vac() enables the sun4c virtual address cache. */
109static inline void sun4c_enable_vac(void)
110{
111 __asm__ __volatile__("lduba [%0] %1, %%g1\n\t"
112 "or %%g1, %2, %%g1\n\t"
113 "stba %%g1, [%0] %1\n\t"
114 : /* no outputs */
115 : "r" ((unsigned int) AC_SENABLE),
116 "i" (ASI_CONTROL), "i" (SENABLE_CACHE)
117 : "g1", "memory");
118 sun4c_vacinfo.on = 1;
119}
120
121/* sun4c_disable_vac() disables the virtual address cache. */
122static inline void sun4c_disable_vac(void)
123{
124 __asm__ __volatile__("lduba [%0] %1, %%g1\n\t"
125 "andn %%g1, %2, %%g1\n\t"
126 "stba %%g1, [%0] %1\n\t"
127 : /* no outputs */
128 : "r" ((unsigned int) AC_SENABLE),
129 "i" (ASI_CONTROL), "i" (SENABLE_CACHE)
130 : "g1", "memory");
131 sun4c_vacinfo.on = 0;
132}
133
134#endif /* !(_SPARC_VAC_OPS_H) */