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+/* $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) */