Commit 93a7ca0c authored Jul 16, 2010 by Cliff Wickman Committed by Ingo Molnar Jul 17, 2010

x86, UV: Initialize BAU MMRs only on hubs with cpus



Remove the initialization of MMRs
UVH_LB_BAU_SB_ACTIVATION_CONTROL and UVH_BAU_DATA_BROADCAST on
UV hubs that have no active cpus. Such initialization on hubs
with no active cpus would result in a kernel page fault.

This is not of real high priority, because we don't have any
such systems (with UV hubs that have no active cpus).  But they
will be coming.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
LKML-Reference: <E1OZmZN-0006cW-RC@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent f6d8a566

arch/x86/kernel/tlb_uv.c

+10 −6

Original line number	Diff line number	Diff line
		@@ -1635,12 +1635,16 @@ static int __init uv_bau_init(void)
		alloc_intr_gate(vector, uv_bau_message_intr1);

		for_each_possible_blade(uvhub) {
		if (uv_blade_nr_possible_cpus(uvhub)) {
		pnode = uv_blade_to_pnode(uvhub);
		/* INIT the bau */
		uv_write_global_mmr64(pnode, UVH_LB_BAU_SB_ACTIVATION_CONTROL,
		uv_write_global_mmr64(pnode,
		UVH_LB_BAU_SB_ACTIVATION_CONTROL,
		((unsigned long)1 << 63));
		mmr = 1; /* should be 1 to broadcast to both sockets */
		uv_write_global_mmr64(pnode, UVH_BAU_DATA_BROADCAST, mmr);
		uv_write_global_mmr64(pnode, UVH_BAU_DATA_BROADCAST,
		mmr);
		}
		}

		return 0;

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