1/* $Id: vac-ops.h,v 1.1.1.1 2008/10/15 03:29:17 james26_jang 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
66/* The indexing of cache lines creates a problem.  Because the line
67 * field of a virtual address extends past the page offset within
68 * the virtual address it is possible to have what are called
69 * 'bad aliases' which will create inconsistencies.  So we must make
70 * sure that within a context that if a physical page is mapped
71 * more than once, that 'extra' line bits are the same.  If this is
72 * not the case, and thus is a 'bad alias' we must turn off the
73 * cacheable bit in the pte's of all such pages.
74 */
75
76#ifdef CONFIG_SUN4
77#define S4CVAC_BADBITS     0x0001e000
78#else
79#define S4CVAC_BADBITS    0x0000f000
80#endif
81
82/* The following is true if vaddr1 and vaddr2 would cause
83 * a 'bad alias'.
84 */
85#define S4CVAC_BADALIAS(vaddr1, vaddr2) \
86        ((((unsigned long) (vaddr1)) ^ ((unsigned long) (vaddr2))) & \
87	 (S4CVAC_BADBITS))
88
89/* The following structure describes the characteristics of a sun4c
90 * VAC as probed from the prom during boot time.
91 */
92struct sun4c_vac_props {
93	unsigned int num_bytes;     /* Size of the cache */
94	unsigned int num_lines;     /* Number of cache lines */
95	unsigned int do_hwflushes;  /* Hardware flushing available? */
96	enum { NONE, WRITE_THROUGH,
97	    WRITE_BACK } type;      /* What type of VAC? */
98	unsigned int linesize;      /* Size of each line in bytes */
99	unsigned int log2lsize;     /* log2(linesize) */
100	unsigned int on;            /* VAC is enabled */
101};
102
103extern struct sun4c_vac_props sun4c_vacinfo;
104
105/* sun4c_enable_vac() enables the sun4c virtual address cache. */
106extern __inline__ void sun4c_enable_vac(void)
107{
108  __asm__ __volatile__("lduba [%0] %1, %%g1\n\t"
109		       "or    %%g1, %2, %%g1\n\t"
110		       "stba  %%g1, [%0] %1\n\t" : :
111		       "r" ((unsigned int) AC_SENABLE),
112		       "i" (ASI_CONTROL), "i" (SENABLE_CACHE) :
113		       "g1");
114  sun4c_vacinfo.on = 1;
115}
116
117/* sun4c_disable_vac() disables the virtual address cache. */
118extern __inline__ void sun4c_disable_vac(void)
119{
120  __asm__ __volatile__("lduba [%0] %1, %%g1\n\t"
121		       "andn  %%g1, %2, %%g1\n\t"
122		       "stba  %%g1, [%0] %1\n\t" : :
123		       "r" ((unsigned int) AC_SENABLE),
124		       "i" (ASI_CONTROL), "i" (SENABLE_CACHE) :
125		       "g1");
126  sun4c_vacinfo.on = 0;
127}
128
129#endif /* !(_SPARC_VAC_OPS_H) */
130