nb/amd/mct_ddr3: Disable MCE framework during DRAM training

On Family 15h processors, with certain RDIMMs, MCEs are generated
as a normal part of DCT startup / DRAM training.  Disable sync
flood on parity or UC data error until ECC has been enabled.

Change-Id: Ife54751ff127ffd59baaad35d3fea14ea01ef505
Signed-off-by: Timothy Pearson <tpearson@raptorengineeringinc.com>
Reviewed-on: https://review.coreboot.org/14186
Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

3 files changed, 29 insertions, 17 deletions

diff --git a/src/northbridge/amd/amdmct/mct_ddr3/mct_d.c b/src/northbridge/amd/amdmct/mct_ddr3/mct_d.c
index f144f8a4b4..6292f0b6ce 100644
--- a/src/northbridge/amd/amdmct/mct_ddr3/mct_d.c
+++ b/src/northbridge/amd/amdmct/mct_ddr3/mct_d.c
@@ -8019,14 +8019,27 @@ void mct_SetDramConfigHi_D(struct MCTStatStruc *pMCTstat,
 
 	printk(BIOS_DEBUG, "mct_SetDramConfigHi_D: DramConfigHi:    %08x\n", DramConfigHi);
 
+	/* Prevent lockups on parity errors during initial DCT startup */
+	if (!pDCTstat->mca_config_backed_up) {
+		dword = Get_NB32(pDCTstat->dev_nbmisc, 0x44);
+		pDCTstat->sync_flood_on_dram_err = (dword >> 30) & 0x1;
+		pDCTstat->sync_flood_on_any_uc_err = (dword >> 21) & 0x1;
+		dword &= ~(0x1 << 30);
+		dword &= ~(0x1 << 21);
+		Set_NB32(pDCTstat->dev_nbmisc, 0x44, dword);
+		pDCTstat->mca_config_backed_up = 1;
+	}
+
 	/* Program the DRAM Configuration High register */
 	Set_NB32_DCT(dev, dct, 0x94, DramConfigHi);
 
 	if (is_fam15h()) {
 		/* Wait until F2x[1, 0]94[FreqChgInProg]=0. */
 		do {
+			printk(BIOS_DEBUG, "*");
 			dword = Get_NB32_DCT(pDCTstat->dev_dct, dct, 0x94);
 		} while (dword & (1 << FreqChgInProg));
+		printk(BIOS_DEBUG, "\n");
 
 		/* Program D18F2x9C_x0D0F_E006_dct[1:0][PllLockTime] = 0xf */
 		dword = Get_NB32_index_wait_DCT(pDCTstat->dev_dct, dct, index_reg, 0x0d0fe006);
diff --git a/src/northbridge/amd/amdmct/mct_ddr3/mct_d.h b/src/northbridge/amd/amdmct/mct_ddr3/mct_d.h
index fd35f9c2c9..6031239c06 100644
--- a/src/northbridge/amd/amdmct/mct_ddr3/mct_d.h
+++ b/src/northbridge/amd/amdmct/mct_ddr3/mct_d.h
@@ -580,6 +580,11 @@ struct DCTStatStruc {		/* A per Node structure*/
 	uint8_t NbPstateThreshold;
 	uint8_t NbPstateHi;
 
+	/* MCA backup variables */
+	uint8_t mca_config_backed_up;
+	uint8_t sync_flood_on_dram_err;
+	uint8_t sync_flood_on_any_uc_err;
+
 	/* New for LB Support */
 	u8 NodePresent;
 	u32 dev_host;
diff --git a/src/northbridge/amd/amdmct/mct_ddr3/mctecc_d.c b/src/northbridge/amd/amdmct/mct_ddr3/mctecc_d.c
index be63149daf..2ebd09324b 100644
--- a/src/northbridge/amd/amdmct/mct_ddr3/mctecc_d.c
+++ b/src/northbridge/amd/amdmct/mct_ddr3/mctecc_d.c
@@ -85,8 +85,6 @@ u8 ECCInit_D(struct MCTStatStruc *pMCTstat, struct DCTStatStruc *pDCTstatA)
 	u16 nvbits;
 
 	uint32_t dword;
-	uint8_t sync_flood_on_dram_err[MAX_NODES_SUPPORTED];
-	uint8_t sync_flood_on_any_uc_err[MAX_NODES_SUPPORTED];
 
 	mctHookBeforeECC();
 
@@ -120,17 +118,6 @@ u8 ECCInit_D(struct MCTStatStruc *pMCTstat, struct DCTStatStruc *pDCTstatA)
 		pDCTstat = pDCTstatA + Node;
 
 		if (NodePresent_D(Node)) {
-			dword = Get_NB32(pDCTstat->dev_nbmisc, 0x44);
-			sync_flood_on_dram_err[Node] = (dword >> 30) & 0x1;
-			sync_flood_on_any_uc_err[Node] = (dword >> 21) & 0x1;
-			dword &= ~(0x1 << 30);
-			dword &= ~(0x1 << 21);
-			Set_NB32(pDCTstat->dev_nbmisc, 0x44, dword);
-
-			/* Clear MC4 error status */
-			pci_write_config32(pDCTstat->dev_nbmisc, 0x48, 0x0);
-			pci_write_config32(pDCTstat->dev_nbmisc, 0x4c, 0x0);
-
 			/* Clear the RAM before enabling ECC to prevent MCE-related lockups */
 			DCTMemClr_Init_D(pMCTstat, pDCTstat);
 			DCTMemClr_Sync_D(pMCTstat, pDCTstat);
@@ -263,10 +250,17 @@ u8 ECCInit_D(struct MCTStatStruc *pMCTstat, struct DCTStatStruc *pDCTstatA)
 		pDCTstat = pDCTstatA + Node;
 
 		if (NodePresent_D(Node)) {
-			dword = Get_NB32(pDCTstat->dev_nbmisc, 0x44);
-			dword |= (sync_flood_on_dram_err[Node] & 0x1) << 30;
-			dword |= (sync_flood_on_any_uc_err[Node] & 0x1) << 21;
-			Set_NB32(pDCTstat->dev_nbmisc, 0x44, dword);
+			/* Clear MC4 error status */
+			pci_write_config32(pDCTstat->dev_nbmisc, 0x48, 0x0);
+			pci_write_config32(pDCTstat->dev_nbmisc, 0x4c, 0x0);
+
+			/* Restore previous MCA error handling settings */
+			if (pDCTstat->mca_config_backed_up) {
+				dword = Get_NB32(pDCTstat->dev_nbmisc, 0x44);
+				dword |= (pDCTstat->sync_flood_on_dram_err & 0x1) << 30;
+				dword |= (pDCTstat->sync_flood_on_any_uc_err & 0x1) << 21;
+				Set_NB32(pDCTstat->dev_nbmisc, 0x44, dword);
+			}
 		}
 	}