/* $Id: vac-ops.h,v 1.13 1998/01/30 10:59:59 jj Exp $ */
#ifndef _SPARC_VAC_OPS_H
#define _SPARC_VAC_OPS_H
/* vac-ops.h: Inline assembly routines to do operations on the Sparc
* VAC (virtual address cache) for the sun4c.
*
* Copyright (C) 1994, David S. Miller (davem@caip.rutgers.edu)
*/
#include <linux/config.h>
#include <asm/sysen.h>
#include <asm/contregs.h>
#include <asm/asi.h>
/* The SUN4C models have a virtually addressed write-through
* cache.
*
* The cache tags are directly accessible through an ASI and
* each have the form:
*
* ------------------------------------------------------------
* | MBZ | CONTEXT | WRITE | PRIV | VALID | MBZ | TagID | MBZ |
* ------------------------------------------------------------
* 31 25 24 22 21 20 19 18 16 15 2 1 0
*
* MBZ: These bits are either unused and/or reserved and should
* be written as zeroes.
*
* CONTEXT: Records the context to which this cache line belongs.
*
* WRITE: A copy of the writable bit from the mmu pte access bits.
*
* PRIV: A copy of the privileged bit from the pte access bits.
*
* VALID: If set, this line is valid, else invalid.
*
* TagID: Fourteen bits of tag ID.
*
* Every virtual address is seen by the cache like this:
*
* ----------------------------------------
* | RESV | TagID | LINE | BYTE-in-LINE |
* ----------------------------------------
* 31 30 29 16 15 4 3 0
*
* RESV: Unused/reserved.
*
* TagID: Used to match the Tag-ID in that vac tags.
*
* LINE: Which line within the cache
*
* BYTE-in-LINE: Which byte within the cache line.
*/
/* Sun4c VAC Tags */
#define S4CVACTAG_CID 0x01c00000
#define S4CVACTAG_W 0x00200000
#define S4CVACTAG_P 0x00100000
#define S4CVACTAG_V 0x00080000
#define S4CVACTAG_TID 0x0000fffc
/* Sun4c VAC Virtual Address */
/* These aren't used, why bother? (Anton) */
#if 0
#define S4CVACVA_TID 0x3fff0000
#define S4CVACVA_LINE 0x0000fff0
#define S4CVACVA_BIL 0x0000000f
#endif
/* The indexing of cache lines creates a problem. Because the line
* field of a virtual address extends past the page offset within
* the virtual address it is possible to have what are called
* 'bad aliases' which will create inconsistencies. So we must make
* sure that within a context that if a physical page is mapped
* more than once, that 'extra' line bits are the same. If this is
* not the case, and thus is a 'bad alias' we must turn off the
* cacheable bit in the pte's of all such pages.
*/
#ifdef CONFIG_SUN4
#define S4CVAC_BADBITS 0x0001e000
#else
#define S4CVAC_BADBITS 0x0000f000
#endif
/* The following is true if vaddr1 and vaddr2 would cause
* a 'bad alias'.
*/
#define S4CVAC_BADALIAS(vaddr1, vaddr2) \
((((unsigned long) (vaddr1)) ^ ((unsigned long) (vaddr2))) & \
(S4CVAC_BADBITS))
/* The following structure describes the characteristics of a sun4c
* VAC as probed from the prom during boot time.
*/
struct sun4c_vac_props {
unsigned int num_bytes; /* Size of the cache */
unsigned int num_lines; /* Number of cache lines */
unsigned int do_hwflushes; /* Hardware flushing available? */
enum { VAC_NONE, VAC_WRITE_THROUGH,
VAC_WRITE_BACK } type; /* What type of VAC? */
unsigned int linesize; /* Size of each line in bytes */
unsigned int log2lsize; /* log2(linesize) */
unsigned int on; /* VAC is enabled */
};
extern struct sun4c_vac_props sun4c_vacinfo;
/* sun4c_enable_vac() enables the sun4c virtual address cache. */
static inline void sun4c_enable_vac(void)
{
__asm__ __volatile__("lduba [%0] %1, %%g1\n\t"
"or %%g1, %2, %%g1\n\t"
"stba %%g1, [%0] %1\n\t"
: /* no outputs */
: "r" ((unsigned int) AC_SENABLE),
"i" (ASI_CONTROL), "i" (SENABLE_CACHE)
: "g1", "memory");
sun4c_vacinfo.on = 1;
}
/* sun4c_disable_vac() disables the virtual address cache. */
static inline void sun4c_disable_vac(void)
{
__asm__ __volatile__("lduba [%0] %1, %%g1\n\t"
"andn %%g1, %2, %%g1\n\t"
"stba %%g1, [%0] %1\n\t"
: /* no outputs */
: "r" ((unsigned int) AC_SENABLE),
"i" (ASI_CONTROL), "i" (SENABLE_CACHE)
: "g1", "memory");
sun4c_vacinfo.on = 0;
}
#endif /* !(_SPARC_VAC_OPS_H) */
