[SPARC64]: Add boot option to force UltraSPARC-III P-Cache on.
Older UltraSPARC-III chips have a P-Cache bug that makes us disable it
by default at boot time.
However, this does hurt performance substantially, particularly with
memcpy(), and the bug is _incredibly_ obscure. I have never seen it
triggered in practice, ever.
So provide a "-P" boot option that forces the P-Cache on. It taints
the kernel, so if it does trigger and cause some data corruption or
OOPS, we will find out in the logs that this option was on when it
happened.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/asm-sparc64/spitfire.h b/include/asm-sparc64/spitfire.h
index ad78ce6..9d7613e 100644
--- a/include/asm-sparc64/spitfire.h
+++ b/include/asm-sparc64/spitfire.h
@@ -48,6 +48,9 @@
extern enum ultra_tlb_layout tlb_type;
+extern int cheetah_pcache_forced_on;
+extern void cheetah_enable_pcache(void);
+
#define sparc64_highest_locked_tlbent() \
(tlb_type == spitfire ? \
SPITFIRE_HIGHEST_LOCKED_TLBENT : \