EDAC/i10nm: Fix NVDIMM detection

[ Upstream commit 2294a72 ]

MCDDRCFG is a per-channel register and uses bit{0,1} to indicate
the NVDIMM presence on DIMM slot{0,1}. Current i10nm_edac driver
wrongly uses MCDDRCFG as per-DIMM register and fails to detect
the NVDIMM.

Fix it by reading MCDDRCFG as per-channel register and using its
bit{0,1} to check whether the NVDIMM is populated on DIMM slot{0,1}.

Fixes: d4dc89d ("EDAC, i10nm: Add a driver for Intel 10nm server processors")
Reported-by: Fan Du <fan.du@intel.com>
Tested-by: Wen Jin <wen.jin@intel.com>
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20210818175701.1611513-2-tony.luck@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/edac/i10nm_base.c

@@ -26,8 +26,8 @@
 	pci_read_config_dword((d)->uracu, 0xd8 + (i) * 4, &(reg))
 #define I10NM_GET_DIMMMTR(m, i, j)	\
 	readl((m)->mbase + 0x2080c + (i) * 0x4000 + (j) * 4)
-#define I10NM_GET_MCDDRTCFG(m, i, j)	\
-	readl((m)->mbase + 0x20970 + (i) * 0x4000 + (j) * 4)
+#define I10NM_GET_MCDDRTCFG(m, i)	\
+	readl((m)->mbase + 0x20970 + (i) * 0x4000)
 #define I10NM_GET_MCMTR(m, i)		\
 	readl((m)->mbase + 0x20ef8 + (i) * 0x4000)
 
@@ -170,10 +170,10 @@ static int i10nm_get_dimm_config(struct mem_ctl_info *mci)
 			continue;
 
 		ndimms = 0;
+		mcddrtcfg = I10NM_GET_MCDDRTCFG(imc, i);
 		for (j = 0; j < I10NM_NUM_DIMMS; j++) {
 			dimm = edac_get_dimm(mci, i, j, 0);
 			mtr = I10NM_GET_DIMMMTR(imc, i, j);
-			mcddrtcfg = I10NM_GET_MCDDRTCFG(imc, i, j);
 			edac_dbg(1, "dimmmtr 0x%x mcddrtcfg 0x%x (mc%d ch%d dimm%d)\n",
 				 mtr, mcddrtcfg, imc->mc, i, j);