EDAC/skx: Use the mcmtr register to retrieve close_pg/bank_xor_enable

The skx_edac driver wrongly uses the mtr register to retrieve two fields
close_pg and bank_xor_enable. Fix it by using the correct mcmtr register
to get the two fields.

Cc: <stable@vger.kernel.org>
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Reported-by: Matthew Riley <mattdr@google.com>
Acked-by: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20200515210146.1337-1-tony.luck@intel.com

drivers/edac/i10nm_base.c

@@ -161,7 +161,7 @@ static int i10nm_get_dimm_config(struct mem_ctl_info *mci)
 				 mtr, mcddrtcfg, imc->mc, i, j);
 
 			if (IS_DIMM_PRESENT(mtr))
-				ndimms += skx_get_dimm_info(mtr, 0, dimm,
+				ndimms += skx_get_dimm_info(mtr, 0, 0, dimm,
 							    imc, i, j);
 			else if (IS_NVDIMM_PRESENT(mcddrtcfg, j))
 				ndimms += skx_get_nvdimm_info(dimm, imc, i, j,

drivers/edac/skx_base.c

@@ -163,27 +163,23 @@ static const struct x86_cpu_id skx_cpuids[] = {
 };
 MODULE_DEVICE_TABLE(x86cpu, skx_cpuids);
 
-#define SKX_GET_MTMTR(dev, reg) \
-	pci_read_config_dword((dev), 0x87c, &(reg))
-
-static bool skx_check_ecc(struct pci_dev *pdev)
+static bool skx_check_ecc(u32 mcmtr)
 {
-	u32 mtmtr;
-
-	SKX_GET_MTMTR(pdev, mtmtr);
-
-	return !!GET_BITFIELD(mtmtr, 2, 2);
+	return !!GET_BITFIELD(mcmtr, 2, 2);
 }
 
 static int skx_get_dimm_config(struct mem_ctl_info *mci)
 {
 	struct skx_pvt *pvt = mci->pvt_info;
+	u32 mtr, mcmtr, amap, mcddrtcfg;
 	struct skx_imc *imc = pvt->imc;
-	u32 mtr, amap, mcddrtcfg;
 	struct dimm_info *dimm;
 	int i, j;
 	int ndimms;
 
+	/* Only the mcmtr on the first channel is effective */
+	pci_read_config_dword(imc->chan[0].cdev, 0x87c, &mcmtr);
+
 	for (i = 0; i < SKX_NUM_CHANNELS; i++) {
 		ndimms = 0;
 		pci_read_config_dword(imc->chan[i].cdev, 0x8C, &amap);
@@ -193,14 +189,14 @@ static int skx_get_dimm_config(struct mem_ctl_info *mci)
 			pci_read_config_dword(imc->chan[i].cdev,
 					      0x80 + 4 * j, &mtr);
 			if (IS_DIMM_PRESENT(mtr)) {
-				ndimms += skx_get_dimm_info(mtr, amap, dimm, imc, i, j);
+				ndimms += skx_get_dimm_info(mtr, mcmtr, amap, dimm, imc, i, j);
 			} else if (IS_NVDIMM_PRESENT(mcddrtcfg, j)) {
 				ndimms += skx_get_nvdimm_info(dimm, imc, i, j,
 							      EDAC_MOD_STR);
 				nvdimm_count++;
 			}
 		}
-		if (ndimms && !skx_check_ecc(imc->chan[0].cdev)) {
+		if (ndimms && !skx_check_ecc(mcmtr)) {
 			skx_printk(KERN_ERR, "ECC is disabled on imc %d\n", imc->mc);
 			return -ENODEV;
 		}

drivers/edac/skx_common.c

@@ -304,7 +304,7 @@ static int skx_get_dimm_attr(u32 reg, int lobit, int hibit, int add,
 #define numrow(reg)	skx_get_dimm_attr(reg, 2, 4, 12, 1, 6, "rows")
 #define numcol(reg)	skx_get_dimm_attr(reg, 0, 1, 10, 0, 2, "cols")
 
-int skx_get_dimm_info(u32 mtr, u32 amap, struct dimm_info *dimm,
+int skx_get_dimm_info(u32 mtr, u32 mcmtr, u32 amap, struct dimm_info *dimm,
 		      struct skx_imc *imc, int chan, int dimmno)
 {
 	int  banks = 16, ranks, rows, cols, npages;
@@ -324,8 +324,8 @@ int skx_get_dimm_info(u32 mtr, u32 amap, struct dimm_info *dimm,
 		 imc->mc, chan, dimmno, size, npages,
 		 banks, 1 << ranks, rows, cols);
 
-	imc->chan[chan].dimms[dimmno].close_pg = GET_BITFIELD(mtr, 0, 0);
-	imc->chan[chan].dimms[dimmno].bank_xor_enable = GET_BITFIELD(mtr, 9, 9);
+	imc->chan[chan].dimms[dimmno].close_pg = GET_BITFIELD(mcmtr, 0, 0);
+	imc->chan[chan].dimms[dimmno].bank_xor_enable = GET_BITFIELD(mcmtr, 9, 9);
 	imc->chan[chan].dimms[dimmno].fine_grain_bank = GET_BITFIELD(amap, 0, 0);
 	imc->chan[chan].dimms[dimmno].rowbits = rows;
 	imc->chan[chan].dimms[dimmno].colbits = cols;

drivers/edac/skx_common.h

@@ -128,7 +128,7 @@ int skx_get_all_bus_mappings(unsigned int did, int off, enum type,
 
 int skx_get_hi_lo(unsigned int did, int off[], u64 *tolm, u64 *tohm);
 
-int skx_get_dimm_info(u32 mtr, u32 amap, struct dimm_info *dimm,
+int skx_get_dimm_info(u32 mtr, u32 mcmtr, u32 amap, struct dimm_info *dimm,
 		      struct skx_imc *imc, int chan, int dimmno);
 
 int skx_get_nvdimm_info(struct dimm_info *dimm, struct skx_imc *imc,