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