sh: Optimized cache handling for SH-4/SH-4A caches.

This reworks some of the SH-4 cache handling code to more easily
accomodate newer-style caches (particularly for the > direct-mapped
case), as well as optimizing some of the old code.

Signed-off-by: Richard Curnow <richard.curnow@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

include/asm-sh/cache.h

@@ -23,15 +23,29 @@
 #define L1_CACHE_ALIGN(x)	(((x)+(L1_CACHE_BYTES-1))&~(L1_CACHE_BYTES-1))
 
 struct cache_info {
-	unsigned int ways;
-	unsigned int sets;
-	unsigned int linesz;
+	unsigned int ways;		/* Number of cache ways */
+	unsigned int sets;		/* Number of cache sets */
+	unsigned int linesz;		/* Cache line size (bytes) */
 
+	unsigned int way_size;		/* sets * line size */
+
+	/*
+	 * way_incr is the address offset for accessing the next way
+	 * in memory mapped cache array ops.
+	 */
 	unsigned int way_incr;
-
 	unsigned int entry_shift;
 	unsigned int entry_mask;
 
+	/*
+	 * Compute a mask which selects the address bits which overlap between
+	 * 1. those used to select the cache set during indexing
+	 * 2. those in the physical page number.
+	 */
+	unsigned int alias_mask;
+
+	unsigned int n_aliases;		/* Number of aliases */
+
 	unsigned long flags;
 };