From: Cliff Wickman <cpw@sgi.com>
Date: Thu, 19 Nov 2009 23:12:43 +0000 (-0600)
Subject: x86: SGI UV: Fix BAU initialization
X-Git-Tag: firefly_0821_release~11625^2~597
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=3715cace63b4751445181cefcb2eba77b30d8525;p=firefly-linux-kernel-4.4.55.git

x86: SGI UV: Fix BAU initialization

commit e38e2af1c57c3eb5211331a5b4fcaae0c4a2a918 upstream.

A memory mapped register that affects the SGI UV Broadcast
Assist Unit's interrupt handling may sometimes be unintialized.

Remove the condition on its initialization, as that condition
can be randomly satisfied by a hardware reset.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
LKML-Reference: <E1NBGB9-0005nU-Dp@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/arch/x86/kernel/tlb_uv.c b/arch/x86/kernel/tlb_uv.c
index 1740c85e24bb..364d015efebc 100644
--- a/arch/x86/kernel/tlb_uv.c
+++ b/arch/x86/kernel/tlb_uv.c
@@ -817,10 +817,8 @@ static int __init uv_init_blade(int blade)
 	 */
 	apicid = blade_to_first_apicid(blade);
 	pa = uv_read_global_mmr64(pnode, UVH_BAU_DATA_CONFIG);
-	if ((pa & 0xff) != UV_BAU_MESSAGE) {
-		uv_write_global_mmr64(pnode, UVH_BAU_DATA_CONFIG,
+	uv_write_global_mmr64(pnode, UVH_BAU_DATA_CONFIG,
 				      ((apicid << 32) | UV_BAU_MESSAGE));
-	}
 	return 0;
 }