[PATCH v2] EDAC/amd64: Fix possible module load failure on some UMC usage combinations

[Avadhut Naik <avadhut.naik@amd.com>]

Starting Zen4, AMD SOCs have 12 Unified Memory Controllers (UMCs) per
socket.

When the amd64_edac module is being loaded, these UMCs are traversed to
determine if they have SdpInit (SdpCtrl[31]) and EccEnabled (UmcCapHi[30])
bits set and create masks in umc_en_mask and ecc_en_mask respectively.

However, the current data type of these variables is u8. As a result, if
only the last 4 UMCs (UMC8 - UMC11) of the system have been utilized,
umc_ecc_enabled() will return false. Consequently, the module may fail to
load on these systems.

Fixes: e2be5955a886 ("EDAC/amd64: Add support for AMD Family 19h Models 10h-1Fh and A0h-AFh")
Signed-off-by: Avadhut Naik <avadhut.naik@amd.com>
Cc: stable@vger.kernel.org
---
Changes in v2:
1. Change data type of variables from u16 to int. (Boris)
2. Modify commit message per feedback. (Boris)
3. Add Fixes: and CC:stable tags. (Boris)
---
 drivers/edac/amd64_edac.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index ddfbdb66b794..b1c034214a8d 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -3362,7 +3362,7 @@ static bool dct_ecc_enabled(struct amd64_pvt *pvt)
 
 static bool umc_ecc_enabled(struct amd64_pvt *pvt)
 {
-	u8 umc_en_mask = 0, ecc_en_mask = 0;
+	int umc_en_mask = 0, ecc_en_mask = 0;
 	u16 nid = pvt->mc_node_id;
 	struct amd64_umc *umc;
 	u8 ecc_en = 0, i;

base-commit: f84722cbed6c2b2094ad8bbe48be2c5900752935
-- 
2.43.0