1/* $Id: vac-ops.h,v 1.1.1.1 2007/08/03 18:53:36 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 65/* The indexing of cache lines creates a problem. Because the line 66 * field of a virtual address extends past the page offset within 67 * the virtual address it is possible to have what are called 68 * 'bad aliases' which will create inconsistencies. So we must make 69 * sure that within a context that if a physical page is mapped 70 * more than once, that 'extra' line bits are the same. If this is 71 * not the case, and thus is a 'bad alias' we must turn off the 72 * cacheable bit in the pte's of all such pages. 73 */ 74 75#ifdef CONFIG_SUN4 76#define S4CVAC_BADBITS 0x0001e000 77#else 78#define S4CVAC_BADBITS 0x0000f000 79#endif 80 81/* The following is true if vaddr1 and vaddr2 would cause 82 * a 'bad alias'. 83 */ 84#define S4CVAC_BADALIAS(vaddr1, vaddr2) \ 85 ((((unsigned long) (vaddr1)) ^ ((unsigned long) (vaddr2))) & \ 86 (S4CVAC_BADBITS)) 87 88/* The following structure describes the characteristics of a sun4c 89 * VAC as probed from the prom during boot time. 90 */ 91struct sun4c_vac_props { 92 unsigned int num_bytes; /* Size of the cache */ 93 unsigned int num_lines; /* Number of cache lines */ 94 unsigned int do_hwflushes; /* Hardware flushing available? */ 95 enum { VAC_NONE, VAC_WRITE_THROUGH, 96 VAC_WRITE_BACK } type; /* What type of VAC? */ 97 unsigned int linesize; /* Size of each line in bytes */ 98 unsigned int log2lsize; /* log2(linesize) */ 99 unsigned int on; /* VAC is enabled */ 100}; 101 102extern struct sun4c_vac_props sun4c_vacinfo; 103 104/* sun4c_enable_vac() enables the sun4c virtual address cache. */ 105static inline void sun4c_enable_vac(void) 106{ 107 __asm__ __volatile__("lduba [%0] %1, %%g1\n\t" 108 "or %%g1, %2, %%g1\n\t" 109 "stba %%g1, [%0] %1\n\t" 110 : /* no outputs */ 111 : "r" ((unsigned int) AC_SENABLE), 112 "i" (ASI_CONTROL), "i" (SENABLE_CACHE) 113 : "g1", "memory"); 114 sun4c_vacinfo.on = 1; 115} 116 117/* sun4c_disable_vac() disables the virtual address cache. */ 118static 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 : /* no outputs */ 124 : "r" ((unsigned int) AC_SENABLE), 125 "i" (ASI_CONTROL), "i" (SENABLE_CACHE) 126 : "g1", "memory"); 127 sun4c_vacinfo.on = 0; 128} 129 130#endif /* !(_SPARC_VAC_OPS_H) */ 131