gru: fix prefetch and speculation bugs
Fix several bugs related to prefetch, ordering & speculation:
- GRU cch_allocate() instruction causes cacheable memory
to be created. Add a barriers to prevent speculation
from prefetching data before it exists.
- Add memory barriers before cache-flush instructions to ensure
that previously stored data is included in the line flushed to memory.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
index 7466234..d3cacd6 100644
--- a/drivers/misc/sgi-gru/grufault.c
+++ b/drivers/misc/sgi-gru/grufault.c
@@ -333,6 +333,7 @@
*/
if (tfh->status != TFHSTATUS_EXCEPTION) {
gru_flush_cache(tfh);
+ sync_core();
if (tfh->status != TFHSTATUS_EXCEPTION)
goto failnoexception;
STAT(tfh_stale_on_fault);
@@ -599,6 +600,7 @@
cbrnum = thread_cbr_number(gts, ucbnum);
cbe = get_cbe_by_index(gts->ts_gru, cbrnum);
gru_flush_cache(cbe); /* CBE not coherent */
+ sync_core(); /* make sure we are have current data */
excdet.opc = cbe->opccpy;
excdet.exopc = cbe->exopccpy;
excdet.ecause = cbe->ecause;