[IA64] allow user to force_pal_cache_flush

The sequence executed in check_sal_cache_flush:

	- pend a timer interrupt
	- call SAL_CACHE_FLUSH
	- see if interrupt is still pending

can hang HP machines with buggy SAL_CACHE_FLUSH implementations.

Provide a kernel command-line argument to allow users skip this
check if desired. Using this parameter will force ia64_sal_cache_flush
to call ia64_pal_cache_flush() instead of SAL_CACHE_FLUSH.

Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index cdd5b93..654d630 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -689,6 +689,12 @@
 	floppy=		[HW]
 			See Documentation/floppy.txt.
 
+	force_pal_cache_flush
+			[IA-64] Avoid check_sal_cache_flush which may hang on
+			buggy SAL_CACHE_FLUSH implementations. Using this
+			parameter will force ia64_sal_cache_flush to call
+			ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
+
 	gamecon.map[2|3]=
 			[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
 			support via parallel port (up to 5 devices per port)