x86: Fix UV BAU destination subnode id

The SGI UV Broadcast Assist Unit is used to send TLB shootdown
messages to remote nodes of the system.  The header of the
message must contain the subnode id of the block in the
receiving hub that handles such messages.  It should always be
0x10, the id of the "LB" block.

It had previously been documented as a "must be zero" field.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
Acked-by: Jack Steiner <steiner@sgi.com>
LKML-Reference: <E1Mc1x7-0005Ce-6t@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 2 insertions, 1 deletions

diff --git a/arch/x86/include/asm/uv/uv_bau.h b/arch/x86/include/asm/uv/uv_bau.h
index bddd44f2f0a..80e2984f521 100644
--- a/arch/x86/include/asm/uv/uv_bau.h
+++ b/arch/x86/include/asm/uv/uv_bau.h
@@ -133,7 +133,7 @@ struct bau_msg_payload {
  * see table 4.2.3.0.1 in broacast_assist spec.
  */
 struct bau_msg_header {
-        unsigned int dest_subnodeid:6;  /* must be zero */
+        unsigned int dest_subnodeid:6;  /* must be 0x10, for the LB */
         /* bits 5:0 */
         unsigned int base_dest_nodeid:15; /* nasid>>1 (pnode) of */
         /* bits 20:6 */                   /* first bit in node_map */
diff --git a/arch/x86/kernel/tlb_uv.c b/arch/x86/kernel/tlb_uv.c
index 8ccabb8a2f6..77b9689f8ed 100644
--- a/arch/x86/kernel/tlb_uv.c
+++ b/arch/x86/kernel/tlb_uv.c
@@ -744,6 +744,7 @@ uv_activation_descriptor_init(int node, int pnode)
                  * note that base_dest_nodeid is actually a nasid.
                  */
                 ad2->header.base_dest_nodeid = uv_partition_base_pnode << 1;
+                ad2->header.dest_subnodeid = 0x10; /* the LB */
                 ad2->header.command = UV_NET_ENDPOINT_INTD;
                 ad2->header.int_both = 1;
                 /*