GRU driver: minor updates

A few minor updates for the GRU driver.
	- documentation changes found in code reviews
	- changes to #ifdefs to make them recognized by "unifdef"
	  (used in simulator testing)
	- change GRU context load/unload to prefetch data

[akpm@linux-foundation.org: fix typo in comment]
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/grukservices.c b/drivers/misc/sgi-gru/grukservices.c
index 08d29cd..880c55d 100644
--- a/drivers/misc/sgi-gru/grukservices.c
+++ b/drivers/misc/sgi-gru/grukservices.c
@@ -122,6 +122,7 @@
 	struct gru_control_block_extended *cbe;
 
 	cbe = get_cbe(GRUBASE(cb), get_cb_number(cb));
+	prefetchw(cbe);         /* Harmless on hardware, required for emulator */
 	excdet->opc = cbe->opccpy;
 	excdet->exopc = cbe->exopccpy;
 	excdet->ecause = cbe->ecause;