Revert "EDAC/amd64: Support more than two controllers for chip select handling"

This reverts commit 0a227af5.

Unfortunately, this commit caused wrong detection of chip select sizes
on some F17h client machines:

  --- 00-rc6+     2019-02-14 14:28:03.126622904 +0100
  +++ 01-rc4+     2019-04-14 21:06:16.060614790 +0200
   EDAC amd64: MC: 0:     0MB 1:     0MB
  -EDAC amd64: MC: 2: 16383MB 3: 16383MB
  +EDAC amd64: MC: 2:     0MB 3: 2097151MB
   EDAC amd64: MC: 4:     0MB 5:     0MB
   EDAC amd64: MC: 6:     0MB 7:     0MB
   EDAC MC: UMC1 chip selects:
   EDAC amd64: MC: 0:     0MB 1:     0MB
  -EDAC amd64: MC: 2: 16383MB 3: 16383MB
  +EDAC amd64: MC: 2:     0MB 3: 2097151MB
   EDAC amd64: MC: 4:     0MB 5:     0MB
   EDAC amd64: MC: 6:     0MB 7:     0M

Revert it for now until it has been solved properly.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Yazen Ghannam <yazen.ghannam@amd.com>

drivers/edac/amd64_edac.c

@@ -941,64 +941,48 @@ static void prep_chip_selects(struct amd64_pvt *pvt)
 	} else if (pvt->fam == 0x15 && pvt->model == 0x30) {
 		pvt->csels[0].b_cnt = pvt->csels[1].b_cnt = 4;
 		pvt->csels[0].m_cnt = pvt->csels[1].m_cnt = 2;
-	} else if (pvt->fam >= 0x17) {
-		int umc;
-
-		for_each_umc(umc) {
-			pvt->csels[umc].b_cnt = 8;
-			pvt->csels[umc].m_cnt = 4;
-		}
-
 	} else {
 		pvt->csels[0].b_cnt = pvt->csels[1].b_cnt = 8;
 		pvt->csels[0].m_cnt = pvt->csels[1].m_cnt = 4;
 	}
 }
 
-static void read_umc_base_mask(struct amd64_pvt *pvt)
-{
-	int cs, umc;
-
-	for_each_umc(umc) {
-		u32 umc_base_reg = get_umc_base(umc) + UMCCH_BASE_ADDR;
-		u32 umc_mask_reg = get_umc_base(umc) + UMCCH_ADDR_MASK;
-
-		for_each_chip_select(cs, 0, pvt) {
-			u32 *base = &pvt->csels[umc].csbases[cs];
-			u32 *mask = &pvt->csels[umc].csmasks[cs];
-
-			u32 base_reg = umc_base_reg + (cs * 4);
-			u32 mask_reg = umc_mask_reg + ((cs >> 1) * 4);
-
-			if (!amd_smn_read(pvt->mc_node_id, base_reg, base))
-				edac_dbg(0, "  DCSB%d[%d]=0x%08x reg: 0x%x\n",
-					 umc, cs, *base, base_reg);
-
-			if (!amd_smn_read(pvt->mc_node_id, mask_reg, mask))
-				edac_dbg(0, "    DCSM%d[%d]=0x%08x reg: 0x%x\n",
-					 umc, cs, *mask, mask_reg);
-		}
-	}
-}
-
 /*
  * Function 2 Offset F10_DCSB0; read in the DCS Base and DCS Mask registers
  */
 static void read_dct_base_mask(struct amd64_pvt *pvt)
 {
-	int cs;
+	int base_reg0, base_reg1, mask_reg0, mask_reg1, cs;
 
 	prep_chip_selects(pvt);
 
-	if (pvt->umc)
-		return read_umc_base_mask(pvt);
+	if (pvt->umc) {
+		base_reg0 = get_umc_base(0) + UMCCH_BASE_ADDR;
+		base_reg1 = get_umc_base(1) + UMCCH_BASE_ADDR;
+		mask_reg0 = get_umc_base(0) + UMCCH_ADDR_MASK;
+		mask_reg1 = get_umc_base(1) + UMCCH_ADDR_MASK;
+	} else {
+		base_reg0 = DCSB0;
+		base_reg1 = DCSB1;
+		mask_reg0 = DCSM0;
+		mask_reg1 = DCSM1;
+	}
 
 	for_each_chip_select(cs, 0, pvt) {
-		int reg0   = DCSB0 + (cs * 4);
-		int reg1   = DCSB1 + (cs * 4);
+		int reg0   = base_reg0 + (cs * 4);
+		int reg1   = base_reg1 + (cs * 4);
 		u32 *base0 = &pvt->csels[0].csbases[cs];
 		u32 *base1 = &pvt->csels[1].csbases[cs];
 
+		if (pvt->umc) {
+			if (!amd_smn_read(pvt->mc_node_id, reg0, base0))
+				edac_dbg(0, "  DCSB0[%d]=0x%08x reg: 0x%x\n",
+					 cs, *base0, reg0);
+
+			if (!amd_smn_read(pvt->mc_node_id, reg1, base1))
+				edac_dbg(0, "  DCSB1[%d]=0x%08x reg: 0x%x\n",
+					 cs, *base1, reg1);
+		} else {
 			if (!amd64_read_dct_pci_cfg(pvt, 0, reg0, base0))
 				edac_dbg(0, "  DCSB0[%d]=0x%08x reg: F2x%x\n",
 					 cs, *base0, reg0);
@@ -1011,13 +995,23 @@ static void read_dct_base_mask(struct amd64_pvt *pvt)
 					 cs, *base1, (pvt->fam == 0x10) ? reg1
 								: reg0);
 		}
+	}
 
 	for_each_chip_select_mask(cs, 0, pvt) {
-		int reg0   = DCSM0 + (cs * 4);
-		int reg1   = DCSM1 + (cs * 4);
+		int reg0   = mask_reg0 + (cs * 4);
+		int reg1   = mask_reg1 + (cs * 4);
 		u32 *mask0 = &pvt->csels[0].csmasks[cs];
 		u32 *mask1 = &pvt->csels[1].csmasks[cs];
 
+		if (pvt->umc) {
+			if (!amd_smn_read(pvt->mc_node_id, reg0, mask0))
+				edac_dbg(0, "    DCSM0[%d]=0x%08x reg: 0x%x\n",
+					 cs, *mask0, reg0);
+
+			if (!amd_smn_read(pvt->mc_node_id, reg1, mask1))
+				edac_dbg(0, "    DCSM1[%d]=0x%08x reg: 0x%x\n",
+					 cs, *mask1, reg1);
+		} else {
 			if (!amd64_read_dct_pci_cfg(pvt, 0, reg0, mask0))
 				edac_dbg(0, "    DCSM0[%d]=0x%08x reg: F2x%x\n",
 					 cs, *mask0, reg0);
@@ -1030,6 +1024,7 @@ static void read_dct_base_mask(struct amd64_pvt *pvt)
 					 cs, *mask1, (pvt->fam == 0x10) ? reg1
 								: reg0);
 		}
+	}
 }
 
 static void determine_memory_type(struct amd64_pvt *pvt)

drivers/edac/amd64_edac.h

@@ -96,7 +96,6 @@
 /* Hardware limit on ChipSelect rows per MC and processors per system */
 #define NUM_CHIPSELECTS			8
 #define DRAM_RANGES			8
-#define NUM_CONTROLLERS			8
 
 #define ON true
 #define OFF false
@@ -352,8 +351,8 @@ struct amd64_pvt {
 	u32 dbam0;		/* DRAM Base Address Mapping reg for DCT0 */
 	u32 dbam1;		/* DRAM Base Address Mapping reg for DCT1 */
 
-	/* one for each DCT/UMC */
-	struct chip_select csels[NUM_CONTROLLERS];
+	/* one for each DCT */
+	struct chip_select csels[2];
 
 	/* DRAM base and limit pairs F1x[78,70,68,60,58,50,48,40] */
 	struct dram_range ranges[DRAM_RANGES];