mips: cm: Add L2 ECC/parity errors reporting

According to the MIPS32 InterAptiv software manual error codes 24 - 26
of CM2 indicate L2 ECC/parity error with switching to a corresponding
errors info fields. This patch provides these errors parsing code,
which handles the read/write uncorrectable and correctable ECC/parity
errors, and prints instruction causing the fault, RAM array type, cache
way/dword and syndrome associated with the faulty data.
Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-pm@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/kernel/mips-cm.c

@@ -114,6 +114,48 @@ static char *cm2_core[8] = {
 	"Exclusive/OK", "Exclusive/Data"
 };
 
+static char *cm2_l2_type[4] = {
+	[0x0] = "None",
+	[0x1] = "Tag RAM single/double ECC error",
+	[0x2] = "Data RAM single/double ECC error",
+	[0x3] = "WS RAM uncorrectable dirty parity"
+};
+
+static char *cm2_l2_instr[32] = {
+	[0x00] = "L2_NOP",
+	[0x01] = "L2_ERR_CORR",
+	[0x02] = "L2_TAG_INV",
+	[0x03] = "L2_WS_CLEAN",
+	[0x04] = "L2_RD_MDYFY_WR",
+	[0x05] = "L2_WS_MRU",
+	[0x06] = "L2_EVICT_LN2",
+	[0x07] = "0x07",
+	[0x08] = "L2_EVICT",
+	[0x09] = "L2_REFL",
+	[0x0a] = "L2_RD",
+	[0x0b] = "L2_WR",
+	[0x0c] = "L2_EVICT_MRU",
+	[0x0d] = "L2_SYNC",
+	[0x0e] = "L2_REFL_ERR",
+	[0x0f] = "0x0f",
+	[0x10] = "L2_INDX_WB_INV",
+	[0x11] = "L2_INDX_LD_TAG",
+	[0x12] = "L2_INDX_ST_TAG",
+	[0x13] = "L2_INDX_ST_DATA",
+	[0x14] = "L2_INDX_ST_ECC",
+	[0x15] = "0x15",
+	[0x16] = "0x16",
+	[0x17] = "0x17",
+	[0x18] = "L2_FTCH_AND_LCK",
+	[0x19] = "L2_HIT_INV",
+	[0x1a] = "L2_HIT_WB_INV",
+	[0x1b] = "L2_HIT_WB",
+	[0x1c] = "0x1c",
+	[0x1d] = "0x1d",
+	[0x1e] = "0x1e",
+	[0x1f] = "0x1f"
+};
+
 static char *cm2_causes[32] = {
 	"None", "GC_WR_ERR", "GC_RD_ERR", "COH_WR_ERR",
 	"COH_RD_ERR", "MMIO_WR_ERR", "MMIO_RD_ERR", "0x07",
@@ -121,7 +163,7 @@ static char *cm2_causes[32] = {
 	"0x0c", "0x0d", "0x0e", "0x0f",
 	"0x10", "INTVN_WR_ERR", "INTVN_RD_ERR", "0x13",
 	"0x14", "0x15", "0x16", "0x17",
-	"0x18", "0x19", "0x1a", "0x1b",
+	"L2_RD_UNCORR", "L2_WR_UNCORR", "L2_CORR", "0x1b",
 	"0x1c", "0x1d", "0x1e", "0x1f"
 };
 
@@ -360,7 +402,7 @@ void mips_cm_error_report(void)
 				 "CCA=%lu TR=%s MCmd=%s STag=%lu "
 				 "SPort=%lu\n", cca_bits, cm2_tr[tr_bits],
 				 cm2_cmd[cmd_bits], stag_bits, sport_bits);
-		} else {
+		} else if (cause < 24) {
 			/* glob state & sresp together */
 			unsigned long c3_bits = (cm_error >> 18) & 7;
 			unsigned long c2_bits = (cm_error >> 15) & 7;
@@ -377,6 +419,22 @@ void mips_cm_error_report(void)
 				 cm2_core[c1_bits], cm2_core[c0_bits],
 				 sc_bit ? "True" : "False",
 				 cm2_cmd[cmd_bits], sport_bits);
+		} else {
+			unsigned long muc_bit = (cm_error >> 23) & 1;
+			unsigned long ins_bits = (cm_error >> 18) & 0x1f;
+			unsigned long arr_bits = (cm_error >> 16) & 3;
+			unsigned long dw_bits = (cm_error >> 12) & 15;
+			unsigned long way_bits = (cm_error >> 9) & 7;
+			unsigned long mway_bit = (cm_error >> 8) & 1;
+			unsigned long syn_bits = (cm_error >> 0) & 0xFF;
+
+			snprintf(buf, sizeof(buf),
+				 "Type=%s%s Instr=%s DW=%lu Way=%lu "
+				 "MWay=%s Syndrome=0x%02lx",
+				 muc_bit ? "Multi-UC " : "",
+				 cm2_l2_type[arr_bits],
+				 cm2_l2_instr[ins_bits], dw_bits, way_bits,
+				 mway_bit ? "True" : "False", syn_bits);
 		}
 		pr_err("CM_ERROR=%08llx %s <%s>\n", cm_error,
 		       cm2_causes[cause], buf);