x86: Fix uv bau sending buffer initialization

The initialization of the UV Broadcast Assist Unit's sending
buffers was making an invalid assumption about the
initialization of an MMR that defines its address.

The BIOS will not be providing that MMR.  So
uv_activation_descriptor_init() should unconditionally set it.

Tested on UV simulator.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: <stable@kernel.org> # for v2.6.30.x
LKML-Reference: <E1MJTfj-0005i1-W8@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/tlb_uv.c b/arch/x86/kernel/tlb_uv.c
index 124d40c575df376e989d5b00229fda865f0bb682..8ccabb8a2f6a617ba512574ec2272e1d5ed5b622 100644 (file)
--- a/arch/x86/kernel/tlb_uv.c
+++ b/arch/x86/kernel/tlb_uv.c
@@ -711,7 +711,6 @@ uv_activation_descriptor_init(int node, int pnode)
        unsigned long pa;
        unsigned long m;
        unsigned long n;
-       unsigned long mmr_image;
        struct bau_desc *adp;
        struct bau_desc *ad2;
 
@@ -727,12 +726,8 @@ uv_activation_descriptor_init(int node, int pnode)
        n = pa >> uv_nshift;
        m = pa & uv_mmask;
 
-       mmr_image = uv_read_global_mmr64(pnode, UVH_LB_BAU_SB_DESCRIPTOR_BASE);
-       if (mmr_image) {
-               uv_write_global_mmr64(pnode, (unsigned long)
-                                     UVH_LB_BAU_SB_DESCRIPTOR_BASE,
-                                     (n << UV_DESC_BASE_PNODE_SHIFT | m));
-       }
+       uv_write_global_mmr64(pnode, UVH_LB_BAU_SB_DESCRIPTOR_BASE,
+                             (n << UV_DESC_BASE_PNODE_SHIFT | m));
 
        /*
         * initializing all 8 (UV_ITEMS_PER_DESCRIPTOR) descriptors for each