[XTENSA] Add support for cache-aliasing

Add support for processors that have cache-aliasing issues, such as
the Stretch S5000 processor. Cache-aliasing means that the size of
the cache (for one way) is larger than the page size, thus, a page
can end up in several places in cache depending on the virtual to
physical translation. The method used here is to map a user page
temporarily through the auto-refill way 0 and of of the DTLB.
We probably will want to revisit this issue and use a better
approach with kmap/kunmap.

Signed-off-by: Chris Zankel <chris@zankel.net>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/asm-xtensa/cache.h b/include/asm-xtensa/cache.h
index 1c4a78f29ae2..3bba2a540cf0 100644
--- a/include/asm-xtensa/cache.h
+++ b/include/asm-xtensa/cache.h
@@ -19,6 +19,15 @@
 
 #define DCACHE_WAY_SIZE (XCHAL_DCACHE_SIZE/XCHAL_DCACHE_WAYS)
 #define ICACHE_WAY_SIZE (XCHAL_ICACHE_SIZE/XCHAL_ICACHE_WAYS)
+#define DCACHE_WAY_SHIFT (XCHAL_DCACHE_SETWIDTH + XCHAL_DCACHE_LINEWIDTH)
+#define ICACHE_WAY_SHIFT (XCHAL_ICACHE_SETWIDTH + XCHAL_ICACHE_LINEWIDTH)
+
+/* Maximum cache size per way. */
+#if DCACHE_WAY_SIZE >= ICACHE_WAY_SIZE
+# define CACHE_WAY_SIZE DCACHE_WAY_SIZE
+#else
+# define CACHE_WAY_SIZE ICACHE_WAY_SIZE
+#endif
 
 
 #endif  /* _XTENSA_CACHE_H */