EDAC, sb_edac: Don't create a second memory controller if HA1 is not present

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>
Fixes: e2f747b1f42a ("EDAC, sb_edac: Assign EDAC memory controller per h/w controller")
Link: http://lkml.kernel.org/r/20170913104214.7325-1-qiuxu.zhuo@intel.com
[ Massage commit message. ]
Signed-off-by: Borislav Petkov <bp@suse.de>

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c
index 3ea90fc5978b..54d9d179cb77 100644
--- a/drivers/edac/sb_edac.c
+++ b/drivers/edac/sb_edac.c
@@ -462,6 +462,7 @@ static const struct pci_id_table pci_dev_descr_sbridge_table[] = {
 static const struct pci_id_descr pci_dev_descr_ibridge[] = {
                 /* Processor Home Agent */
         { PCI_DESCR(PCI_DEVICE_ID_INTEL_IBRIDGE_IMC_HA0,        0, IMC0) },
+        { PCI_DESCR(PCI_DEVICE_ID_INTEL_IBRIDGE_IMC_HA1,        1, IMC1) },
 
                 /* Memory controller */
         { PCI_DESCR(PCI_DEVICE_ID_INTEL_IBRIDGE_IMC_HA0_TA,     0, IMC0) },
@@ -472,7 +473,6 @@ static const struct pci_id_descr pci_dev_descr_ibridge[] = {
         { PCI_DESCR(PCI_DEVICE_ID_INTEL_IBRIDGE_IMC_HA0_TAD3,   0, IMC0) },
 
                 /* Optional, mode 2HA */
-        { PCI_DESCR(PCI_DEVICE_ID_INTEL_IBRIDGE_IMC_HA1,        1, IMC1) },
         { PCI_DESCR(PCI_DEVICE_ID_INTEL_IBRIDGE_IMC_HA1_TA,     1, IMC1) },
         { PCI_DESCR(PCI_DEVICE_ID_INTEL_IBRIDGE_IMC_HA1_RAS,    1, IMC1) },
         { PCI_DESCR(PCI_DEVICE_ID_INTEL_IBRIDGE_IMC_HA1_TAD0,   1, IMC1) },
@@ -2291,6 +2291,13 @@ static int sbridge_get_onedevice(struct pci_dev **prev,
 next_imc:
         sbridge_dev = get_sbridge_dev(bus, dev_descr->dom, multi_bus, sbridge_dev);
         if (!sbridge_dev) {
+                /* If the HA1 wasn't found, don't create EDAC second memory controller */
+                if (dev_descr->dom == IMC1 && devno != 1) {
+                        edac_dbg(0, "Skip IMC1: %04x:%04x (since HA1 was absent)\n",
+                                 PCI_VENDOR_ID_INTEL, dev_descr->dev_id);
+                        pci_dev_put(pdev);
+                        return 0;
+                }
 
                 if (dev_descr->dom == SOCK)
                         goto out_imc;