powerpc/pseries: Add kernel parameter to disable batched hcalls

This introduces a pair of kernel parameters that can be used to disable
the MULTITCE and BULK_REMOVE h-calls.

By default, those hcalls are enabled, active, and good for throughput
and performance.  The ability to disable them will be useful for some of
the PREEMPT_RT related investigation and work occurring on Power.

Signed-off-by: Will Schmidt <will_schmidt@vnet.ibm.com>
cc: Olof Johansson <olof@lixom.net>
cc: Anton Blanchard <anton@samba.org>
cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index cdd2a6e8a3b7..69bb6a9c871a 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -403,6 +403,10 @@ and is between 256 and 4096 characters. It is defined in the file
         bttv.pll=       See Documentation/video4linux/bttv/Insmod-options
         bttv.tuner=     and Documentation/video4linux/bttv/CARDLIST
 
+        bulk_remove=off [PPC]  This parameter disables the use of the pSeries
+                        firmware feature for flushing multiple hpte entries
+                        at a time.
+
         c101=           [NET] Moxa C101 synchronous serial card
 
         cachesize=      [BUGS=X86-32] Override level 2 CPU cache size detection.
@@ -1490,6 +1494,10 @@ and is between 256 and 4096 characters. It is defined in the file
         mtdparts=       [MTD]
                         See drivers/mtd/cmdlinepart.c.
 
+        multitce=off    [PPC]  This parameter disables the use of the pSeries
+                        firmware feature for updating multiple TCE entries
+                        at a time.
+
         onenand.bdry=   [HW,MTD] Flex-OneNAND Boundary Configuration
 
                         Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock]