c 213323 breaks Sony Vaio P11Z w/o acpi

Hi Andriy & list!

Since rev 213323 my Sony Vaio P11Z was unable to boot up. It broke with 
a divide by zero in topo_probe_0x4 at line 289 as cpu_logical is 0.

The cpu is an Intel Atom Z520 (single core). System doesn't boot at all 
w/ acpi enabled.

The following patch made me to boot up again.

Index: i386/i386/mp_machdep.c
===================================================================
--- i386/i386/mp_machdep.c	(revision 213936)
+++ i386/i386/mp_machdep.c	(working copy)
_at__at_ -286,7 +286,7 _at__at_
  			cpu_logical++;
  	}

-	cpu_cores /= cpu_logical;
+	cpu_cores /= cpu_logical==0?1:cpu_logical;
  	hyperthreading_cpus = cpu_logical;
  }

``mptable -grope -verbose`` gives:
===============================================================================

MPTable

  looking for EBDA pointer _at_ 0x040e, found, searching EBDA _at_ 0x0009fc00
  searching CMOS 'top of mem' _at_ 0x0009f800 (638K)
  searching default 'top of mem' _at_ 0x0009fc00 (639K)
  searching BIOS _at_ 0x000f0000
  searching extended BIOS _at_ 0x000e0000
  groping memory _at_ 0x00080000
  groping memory _at_ 0x00090000

  MP FPS NOT found,
  suggest trying -grope option!!!

so it's not of much help.

relevant part of dmesg looks like:

FreeBSD 9.0-CURRENT #3 r213904:213936M: Sat Oct 16 22:50:53 UTC 2010
     root_at_juno.sz.vwsoft.com:/usr/obj/usr/src/sys/JUNO i386
CPU: Intel(R) Atom(TM) CPU Z520   _at_ 1.33GHz (1333.31-MHz 686-class CPU)
   Origin = "GenuineIntel"  Id = 0x106c2  Family = 6  Model = 1c 
Stepping = 2
 
Features=0xbfe9fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
 
Features2=0x40c3bd<SSE3,DTES64,MON,DS_CPL,VMX,EST,TM2,SSSE3,xTPR,PDCM,MOVBE>
   AMD Features=0x100000<NX>
   AMD Features2=0x1<LAHF>
   TSC: P-state invariant
real memory  = 2147483648 (2048 MB)
avail memory = 2081042432 (1984 MB)

I'm wondering if there's a better way to fix that problem or if someone 
wants to commit my fix.

Thanks,

Volker