NUMA-Q breakage 2/7 xquad_portio ioremap deadlock

[William Lee Irwin III <wli@holomorphy.com>]

The cpu_online_map stuff for hotplug cpu created a brand new bootstrap
ordering problem for NUMA-Q. The mmapped portio region needs to be
ioremapped early but ioremap attempts to do TLB shootdown, and
smp_call_function() (called by flush_tlb_all()) deadlocks when
cpu_online_map is uninitialized.

Workaround (due to Matt Dobson) below.



diff -Nur linux-2.5.23-vanilla/arch/i386/kernel/smp.c linux-2.5.23-patched/arch/i386/kernel/smp.c
--- linux-2.5.23-vanilla/arch/i386/kernel/smp.c	Tue Jun 18 19:11:47 2002
+++ linux-2.5.23-patched/arch/i386/kernel/smp.c	Mon Jul  8 14:52:32 2002
@@ -569,7 +569,7 @@
 	struct call_data_struct data;
 	int cpus = num_online_cpus()-1;
 
-	if (!cpus)
+	if (cpus <= 0)
 		return 0;
 
 	data.func = func;