Aladyshev Konstantin has uploaded this change for review.

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AGESA: f15 f15tn f16kb: Add extra check for incorrect SPD data

If memory module is broken and its SPD data is wrong in a way
that Data[11] or Data[9]&0xF is equal to zero, division by 0
in DIMM speed calculation could reboot CPU. Add extra check
to avoid this issue.

Change-Id: Ica92850cc77e1f7cbf3e7e44717de42a03b93bbe
Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
---
M src/vendorcode/amd/agesa/f15/Proc/Mem/Feat/DMI/mfDMI.c
M src/vendorcode/amd/agesa/f15tn/Proc/Mem/Feat/DMI/mfDMI.c
M src/vendorcode/amd/agesa/f16kb/Proc/Mem/Feat/DMI/mfDMI.c
3 files changed, 21 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/39/20839/1

diff --git a/src/vendorcode/amd/agesa/f15/Proc/Mem/Feat/DMI/mfDMI.c b/src/vendorcode/amd/agesa/f15/Proc/Mem/Feat/DMI/mfDMI.c
index 3138f3f..b968349 100644
--- a/src/vendorcode/amd/agesa/f15/Proc/Mem/Feat/DMI/mfDMI.c
+++ b/src/vendorcode/amd/agesa/f15/Proc/Mem/Feat/DMI/mfDMI.c
@@ -228,6 +228,13 @@
           DmiTable[DimmIndex].PartNumber[i] = 0x0;
         }
 
+	// If SPD is wrong, division by 0 in DIMM speed calculation could reboot CPU
+	// So avoid it by this check
+	if ((SpdDataStructure[DimmIndex].Data[11]==0) || ((SpdDataStructure[DimmIndex].Data[9] & 0xF) == 0)) {
+		DmiTable[DimmIndex].DimmPresent = 0;
+		SpdDataStructure[DimmIndex].DimmPresent = 0;
+	}
+
         if (SpdDataStructure[DimmIndex].DimmPresent) {
           // Total Width (offset 08h) & Data Width (offset 0Ah)
           TotalWidth = (UINT16) SpdDataStructure[DimmIndex].Data[8];
diff --git a/src/vendorcode/amd/agesa/f15tn/Proc/Mem/Feat/DMI/mfDMI.c b/src/vendorcode/amd/agesa/f15tn/Proc/Mem/Feat/DMI/mfDMI.c
index 6620030..61499f5 100644
--- a/src/vendorcode/amd/agesa/f15tn/Proc/Mem/Feat/DMI/mfDMI.c
+++ b/src/vendorcode/amd/agesa/f15tn/Proc/Mem/Feat/DMI/mfDMI.c
@@ -243,6 +243,13 @@
           DmiTable[DimmIndex].PartNumber[i] = 0x0;
         }
 
+	// If SPD is wrong, division by 0 in DIMM speed calculation could reboot CPU
+	// So avoid it by this check
+	if ((SpdDataStructure[DimmIndex].Data[11]==0) || ((SpdDataStructure[DimmIndex].Data[9] & 0xF) == 0)) {
+		DmiTable[DimmIndex].DimmPresent = 0;
+		SpdDataStructure[DimmIndex].DimmPresent = 0;
+	}
+
         if (SpdDataStructure[DimmIndex].DimmPresent) {
           // Total Width (offset 08h) & Data Width (offset 0Ah)
           TotalWidth = (UINT16) SpdDataStructure[DimmIndex].Data[8];
diff --git a/src/vendorcode/amd/agesa/f16kb/Proc/Mem/Feat/DMI/mfDMI.c b/src/vendorcode/amd/agesa/f16kb/Proc/Mem/Feat/DMI/mfDMI.c
index 57cc491..edaf9ee 100644
--- a/src/vendorcode/amd/agesa/f16kb/Proc/Mem/Feat/DMI/mfDMI.c
+++ b/src/vendorcode/amd/agesa/f16kb/Proc/Mem/Feat/DMI/mfDMI.c
@@ -293,6 +293,13 @@
           DmiPhysicalDimmInfoTable->PartNumber[i] = 0x0;
         }
 
+	// If SPD is wrong, division by 0 in DIMM speed calculation could reboot CPU
+	// So avoid it by this check
+	if ((SpdDataStructure[DimmIndex].Data[11]==0) || ((SpdDataStructure[DimmIndex].Data[9] & 0xF) == 0)) {
+		DmiTable[DimmIndex].DimmPresent = 0;
+		SpdDataStructure[DimmIndex].DimmPresent = 0;
+	}
+
         if (SpdDataStructure->DimmPresent) {
           // Total Width (offset 08h) & Data Width (offset 0Ah)
           TotalWidth = (UINT16) SpdDataStructure->Data[8];

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