EDAC, sb_edac: Check if ECC enabled when at least one DIMM is present

This is based on previous work by Patrick Geary, see Link.

Additional cleanups ontop:

 - Remove the code to read MCMTR from pci_ha1_ta and CHN_TO_HA macro,
 now that TA0 and TA1 are unified.

 - Remove get_pdev_same_bus(), since in get_dimm_config() the
 variable "pvt->pci_ta" for KNL is also ready, we can simply use
 pci_read_config_dword(pvt->pci_ta, KNL_MCMTR, &pvt->info.mcmtr) to read
 MCMTR.

Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: https://lkml.kernel.org/r/57884350.1030401@supermicro.com
Link: http://lkml.kernel.org/r/20170523000910.87925-1-qiuxu.zhuo@intel.com
[ Make __populate_dimms() return int. ]
Signed-off-by: Borislav Petkov <bp@suse.de>

diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c
index b9564f767269c3e5d427ef4e2e280b12e3ee09f6..30eb91011ac91cfbd1b72a1d1e0922dea11264d4 100644 (file)
--- a/drivers/edac/sb_edac.c
+++ b/drivers/edac/sb_edac.c
@@ -1060,79 +1060,6 @@ static int haswell_chan_hash(int idx, u64 addr)
        return idx;
 }
 
-/****************************************************************************
-                       Memory check routines
- ****************************************************************************/
-static struct pci_dev *get_pdev_same_bus(u8 bus, u32 id)
-{
-       struct pci_dev *pdev = NULL;
-
-       do {
-               pdev = pci_get_device(PCI_VENDOR_ID_INTEL, id, pdev);
-               if (pdev && pdev->bus->number == bus)
-                       break;
-       } while (pdev);
-
-       return pdev;
-}
-
-/**
- * check_if_ecc_is_active() - Checks if ECC is active
- * @bus:       Device bus
- * @type:      Memory controller type
- * returns: 0 in case ECC is active, -ENODEV if it can't be determined or
- *         disabled
- */
-static int check_if_ecc_is_active(const u8 bus, enum type type)
-{
-       struct pci_dev *pdev = NULL;
-       u32 mcmtr, id;
-
-       switch (type) {
-       case IVY_BRIDGE:
-               id = PCI_DEVICE_ID_INTEL_IBRIDGE_IMC_HA0_TA;
-               break;
-       case HASWELL:
-               id = PCI_DEVICE_ID_INTEL_HASWELL_IMC_HA0_TA;
-               break;
-       case SANDY_BRIDGE:
-               id = PCI_DEVICE_ID_INTEL_SBRIDGE_IMC_TA;
-               break;
-       case BROADWELL:
-               id = PCI_DEVICE_ID_INTEL_BROADWELL_IMC_HA0_TA;
-               break;
-       case KNIGHTS_LANDING:
-               /*
-                * KNL doesn't group things by bus the same way
-                * SB/IB/Haswell does.
-                */
-               id = PCI_DEVICE_ID_INTEL_KNL_IMC_TA;
-               break;
-       default:
-               return -ENODEV;
-       }
-
-       if (type != KNIGHTS_LANDING)
-               pdev = get_pdev_same_bus(bus, id);
-       else
-               pdev = pci_get_device(PCI_VENDOR_ID_INTEL, id, 0);
-
-       if (!pdev) {
-               sbridge_printk(KERN_ERR, "Couldn't find PCI device "
-                                       "%04x:%04x! on bus %02d\n",
-                                       PCI_VENDOR_ID_INTEL, id, bus);
-               return -ENODEV;
-       }
-
-       pci_read_config_dword(pdev,
-                       type == KNIGHTS_LANDING ? KNL_MCMTR : MCMTR, &mcmtr);
-       if (!IS_ECC_ENABLED(mcmtr)) {
-               sbridge_printk(KERN_ERR, "ECC is disabled. Aborting\n");
-               return -ENODEV;
-       }
-       return 0;
-}
-
 /* Low bits of TAD limit, and some metadata. */
 static const u32 knl_tad_dram_limit_lo[] = {
        0x400, 0x500, 0x600, 0x700,
@@ -1620,9 +1547,9 @@ static void get_source_id(struct mem_ctl_info *mci)
                pvt->sbridge_dev->source_id = SOURCE_ID(reg);
 }
 
-static void __populate_dimms(struct mem_ctl_info *mci,
-                            u64 knl_mc_sizes[KNL_MAX_CHANNELS],
-                            enum edac_type mode)
+static int __populate_dimms(struct mem_ctl_info *mci,
+                           u64 knl_mc_sizes[KNL_MAX_CHANNELS],
+                           enum edac_type mode)
 {
        struct sbridge_pvt *pvt = mci->pvt_info;
        int channels = pvt->info.type == KNIGHTS_LANDING ? KNL_MAX_CHANNELS
@@ -1671,6 +1598,12 @@ static void __populate_dimms(struct mem_ctl_info *mci,
                        }
                        edac_dbg(4, "Channel #%d  MTR%d = %x\n", i, j, mtr);
                        if (IS_DIMM_PRESENT(mtr)) {
+                               if (!IS_ECC_ENABLED(pvt->info.mcmtr)) {
+                                       sbridge_printk(KERN_ERR, "CPU SrcID #%d, Ha #%d, Channel #%d has DIMMs, but ECC is disabled\n",
+                                                      pvt->sbridge_dev->source_id,
+                                                      pvt->sbridge_dev->dom, i);
+                                       return -ENODEV;
+                               }
                                pvt->channel[i].dimms++;
 
                                ranks = numrank(pvt->info.type, mtr);
@@ -1704,6 +1637,8 @@ static void __populate_dimms(struct mem_ctl_info *mci,
                        }
                }
        }
+
+       return 0;
 }
 
 static int get_dimm_config(struct mem_ctl_info *mci)
@@ -1732,6 +1667,7 @@ static int get_dimm_config(struct mem_ctl_info *mci)
 
                if (knl_get_dimm_capacity(pvt, knl_mc_sizes) != 0)
                        return -1;
+               pci_read_config_dword(pvt->pci_ta, KNL_MCMTR, &pvt->info.mcmtr);
        } else {
                pci_read_config_dword(pvt->pci_ras, RASENABLES, &reg);
                if (IS_MIRROR_ENABLED(reg)) {
@@ -1761,9 +1697,7 @@ static int get_dimm_config(struct mem_ctl_info *mci)
                }
        }
 
-       __populate_dimms(mci, knl_mc_sizes, mode);
-
-       return 0;
+       return __populate_dimms(mci, knl_mc_sizes, mode);
 }
 
 static void get_memory_layout(const struct mem_ctl_info *mci)
@@ -3180,11 +3114,6 @@ static int sbridge_register_mci(struct sbridge_dev *sbridge_dev, enum type type)
        struct pci_dev *pdev = sbridge_dev->pdev[0];
        int rc;
 
-       /* Check the number of active and not disabled channels */
-       rc = check_if_ecc_is_active(sbridge_dev->bus, type);
-       if (unlikely(rc < 0))
-               return rc;
-
        /* allocate a new MC control structure */
        layers[0].type = EDAC_MC_LAYER_CHANNEL;
        layers[0].size = type == KNIGHTS_LANDING ?
@@ -3347,7 +3276,11 @@ static int sbridge_register_mci(struct sbridge_dev *sbridge_dev, enum type type)
        }
 
        /* Get dimm basic config and the memory layout */
-       get_dimm_config(mci);
+       rc = get_dimm_config(mci);
+       if (rc < 0) {
+               edac_dbg(0, "MC: failed to get_dimm_config()\n");
+               goto fail;
+       }
        get_memory_layout(mci);
 
        /* record ptr to the generic device */