commit 15cc3ae0 upstream.

Yi Zhang reported the following failure on a 2-socket Haswell (E5-2603v3)
server (DELL PowerEdge 730xd):

  EDAC sbridge: Some needed devices are missing
  EDAC MC: Removed device 0 for sb_edac.c Haswell SrcID#0_Ha#0: DEV 0000:7f:12.0
  EDAC MC: Removed device 1 for sb_edac.c Haswell SrcID#1_Ha#0: DEV 0000:ff:12.0
  EDAC sbridge: Couldn't find mci handler
  EDAC sbridge: Couldn't find mci handler
  EDAC sbridge: Failed to register device with error -19.

The refactored sb_edac driver creates the IMC1 (the 2nd memory
controller) if any IMC1 device is present. In this case only
HA1_TA of IMC1 was present, but the driver expected to find
HA1/HA1_TM/HA1_TAD[0-3] devices too, leading to the above failure.

The document [1] says the 'E5-2603 v3' CPU has 4 memory channels max. Yi
Zhang inserted one DIMM per channel for each CPU, and did random error
address injection test with this patch:

      4024  addresses fell in TOLM hole area
     12715  addresses fell in CPU_SrcID#0_Ha#0_Chan#0_DIMM#0
     12774  addresses fell in CPU_SrcID#0_Ha#0_Chan#1_DIMM#0
     12798  addresses fell in CPU_SrcID#0_Ha#0_Chan#2_DIMM#0
     12913  addresses fell in CPU_SrcID#0_Ha#0_Chan#3_DIMM#0
     12674  addresses fell in CPU_SrcID#1_Ha#0_Chan#0_DIMM#0
     12686  addresses fell in CPU_SrcID#1_Ha#0_Chan#1_DIMM#0
     12882  addresses fell in CPU_SrcID#1_Ha#0_Chan#2_DIMM#0
     12934  addresses fell in CPU_SrcID#1_Ha#0_Chan#3_DIMM#0
    106400  addresses were injected totally.

The test result shows that all the 4 channels belong to IMC0 per CPU, so
the server really only has one IMC per CPU.

In the 1st page of chapter 2 in datasheet [2], it also says 'E5-2600 v3'
implements either one or two IMCs. For CPUs with one IMC, IMC1 is not
used and should be ignored.

Thus, do not create a second memory controller if the key HA1 is absent.

[1] http://ark.intel.com/products/83349/Intel-Xeon-Processor-E5-2603-v3-15M-Cache-1_60-GHz
[2] https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/xeon-e5-v3-datasheet-vol-2.pdf



Reported-and-tested-by: Yi Zhang <yizhan@redhat.com>
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20170913104214.7325-1-qiuxu.zhuo@intel.com


[ Massage commit message. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>