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1 | /* $Id: vac-ops.h,v 1.13 1998/01/30 10:59:59 jj Exp $ */ |
2 | #ifndef _SPARC_VAC_OPS_H | |
3 | #define _SPARC_VAC_OPS_H | |
4 | ||
5 | /* vac-ops.h: Inline assembly routines to do operations on the Sparc | |
6 | * VAC (virtual address cache) for the sun4c. | |
7 | * | |
8 | * Copyright (C) 1994, David S. Miller (davem@caip.rutgers.edu) | |
9 | */ | |
10 | ||
11 | #include <linux/config.h> | |
12 | #include <asm/sysen.h> | |
13 | #include <asm/contregs.h> | |
14 | #include <asm/asi.h> | |
15 | ||
16 | /* The SUN4C models have a virtually addressed write-through | |
17 | * cache. | |
18 | * | |
19 | * The cache tags are directly accessible through an ASI and | |
20 | * each have the form: | |
21 | * | |
22 | * ------------------------------------------------------------ | |
23 | * | MBZ | CONTEXT | WRITE | PRIV | VALID | MBZ | TagID | MBZ | | |
24 | * ------------------------------------------------------------ | |
25 | * 31 25 24 22 21 20 19 18 16 15 2 1 0 | |
26 | * | |
27 | * MBZ: These bits are either unused and/or reserved and should | |
28 | * be written as zeroes. | |
29 | * | |
30 | * CONTEXT: Records the context to which this cache line belongs. | |
31 | * | |
32 | * WRITE: A copy of the writable bit from the mmu pte access bits. | |
33 | * | |
34 | * PRIV: A copy of the privileged bit from the pte access bits. | |
35 | * | |
36 | * VALID: If set, this line is valid, else invalid. | |
37 | * | |
38 | * TagID: Fourteen bits of tag ID. | |
39 | * | |
40 | * Every virtual address is seen by the cache like this: | |
41 | * | |
42 | * ---------------------------------------- | |
43 | * | RESV | TagID | LINE | BYTE-in-LINE | | |
44 | * ---------------------------------------- | |
45 | * 31 30 29 16 15 4 3 0 | |
46 | * | |
47 | * RESV: Unused/reserved. | |
48 | * | |
49 | * TagID: Used to match the Tag-ID in that vac tags. | |
50 | * | |
51 | * LINE: Which line within the cache | |
52 | * | |
53 | * BYTE-in-LINE: Which byte within the cache line. | |
54 | */ | |
55 | ||
56 | /* Sun4c VAC Tags */ | |
57 | #define S4CVACTAG_CID 0x01c00000 | |
58 | #define S4CVACTAG_W 0x00200000 | |
59 | #define S4CVACTAG_P 0x00100000 | |
60 | #define S4CVACTAG_V 0x00080000 | |
61 | #define S4CVACTAG_TID 0x0000fffc | |
62 | ||
63 | /* Sun4c VAC Virtual Address */ | |
64 | /* These aren't used, why bother? (Anton) */ | |
65 | #if 0 | |
66 | #define S4CVACVA_TID 0x3fff0000 | |
67 | #define S4CVACVA_LINE 0x0000fff0 | |
68 | #define S4CVACVA_BIL 0x0000000f | |
69 | #endif | |
70 | ||
71 | /* The indexing of cache lines creates a problem. Because the line | |
72 | * field of a virtual address extends past the page offset within | |
73 | * the virtual address it is possible to have what are called | |
74 | * 'bad aliases' which will create inconsistencies. So we must make | |
75 | * sure that within a context that if a physical page is mapped | |
76 | * more than once, that 'extra' line bits are the same. If this is | |
77 | * not the case, and thus is a 'bad alias' we must turn off the | |
78 | * cacheable bit in the pte's of all such pages. | |
79 | */ | |
80 | ||
81 | #ifdef CONFIG_SUN4 | |
82 | #define S4CVAC_BADBITS 0x0001e000 | |
83 | #else | |
84 | #define S4CVAC_BADBITS 0x0000f000 | |
85 | #endif | |
86 | ||
87 | /* The following is true if vaddr1 and vaddr2 would cause | |
88 | * a 'bad alias'. | |
89 | */ | |
90 | #define S4CVAC_BADALIAS(vaddr1, vaddr2) \ | |
91 | ((((unsigned long) (vaddr1)) ^ ((unsigned long) (vaddr2))) & \ | |
92 | (S4CVAC_BADBITS)) | |
93 | ||
94 | /* The following structure describes the characteristics of a sun4c | |
95 | * VAC as probed from the prom during boot time. | |
96 | */ | |
97 | struct sun4c_vac_props { | |
98 | unsigned int num_bytes; /* Size of the cache */ | |
99 | unsigned int num_lines; /* Number of cache lines */ | |
100 | unsigned int do_hwflushes; /* Hardware flushing available? */ | |
101 | enum { VAC_NONE, VAC_WRITE_THROUGH, | |
102 | VAC_WRITE_BACK } type; /* What type of VAC? */ | |
103 | unsigned int linesize; /* Size of each line in bytes */ | |
104 | unsigned int log2lsize; /* log2(linesize) */ | |
105 | unsigned int on; /* VAC is enabled */ | |
106 | }; | |
107 | ||
108 | extern struct sun4c_vac_props sun4c_vacinfo; | |
109 | ||
110 | /* sun4c_enable_vac() enables the sun4c virtual address cache. */ | |
111 | static inline void sun4c_enable_vac(void) | |
112 | { | |
113 | __asm__ __volatile__("lduba [%0] %1, %%g1\n\t" | |
114 | "or %%g1, %2, %%g1\n\t" | |
115 | "stba %%g1, [%0] %1\n\t" | |
116 | : /* no outputs */ | |
117 | : "r" ((unsigned int) AC_SENABLE), | |
118 | "i" (ASI_CONTROL), "i" (SENABLE_CACHE) | |
119 | : "g1", "memory"); | |
120 | sun4c_vacinfo.on = 1; | |
121 | } | |
122 | ||
123 | /* sun4c_disable_vac() disables the virtual address cache. */ | |
124 | static inline void sun4c_disable_vac(void) | |
125 | { | |
126 | __asm__ __volatile__("lduba [%0] %1, %%g1\n\t" | |
127 | "andn %%g1, %2, %%g1\n\t" | |
128 | "stba %%g1, [%0] %1\n\t" | |
129 | : /* no outputs */ | |
130 | : "r" ((unsigned int) AC_SENABLE), | |
131 | "i" (ASI_CONTROL), "i" (SENABLE_CACHE) | |
132 | : "g1", "memory"); | |
133 | sun4c_vacinfo.on = 0; | |
134 | } | |
135 | ||
136 | #endif /* !(_SPARC_VAC_OPS_H) */ |