LXR linux/include/asm-sparc/vac-ops.h

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