EDAC/amd64: Simplify ECC check on unified memory controllers

JIRA: https://issues.redhat.com/browse/RHEL-73049
Tested: by me

commit 7473673
Author: Borislav Petkov (AMD) <[email protected]>
Date:   Wed Dec 11 12:07:42 2024 +0100

    EDAC/amd64: Simplify ECC check on unified memory controllers

    The intent of the check is to see whether at least one UMC has ECC
    enabled. So do that instead of tracking which ones are enabled in masks
    which are too small in size anyway and lead to not loading the driver on
    Zen4 machines with UMCs enabled over UMC8.

    Fixes: e2be595 ("EDAC/amd64: Add support for AMD Family 19h Models 10h-1Fh and A0h-AFh")
    Reported-by: Avadhut Naik <[email protected]>
    Signed-off-by: Borislav Petkov (AMD) <[email protected]>
    Tested-by: Avadhut Naik <[email protected]>
    Reviewed-by: Avadhut Naik <[email protected]>
    Cc: <[email protected]>
    Link: https://lore.kernel.org/r/[email protected]

Signed-off-by: Aristeu Rozanski <[email protected]>

Author: aristeu

drivers/edac/amd64_edac.c

@@ -3363,36 +3363,24 @@ 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;
-	u16 nid = pvt->mc_node_id;
 	struct amd64_umc *umc;
-	u8 ecc_en = 0, i;
+	bool ecc_en = false;
+	int i;
 
+	/* Check whether at least one UMC is enabled: */
 	for_each_umc(i) {
 		umc = &pvt->umc[i];
 
-		/* Only check enabled UMCs. */
-		if (!(umc->sdp_ctrl & UMC_SDP_INIT))
-			continue;
-
-		umc_en_mask |= BIT(i);
-
-		if (umc->umc_cap_hi & UMC_ECC_ENABLED)
-			ecc_en_mask |= BIT(i);
+		if (umc->sdp_ctrl & UMC_SDP_INIT &&
+		    umc->umc_cap_hi & UMC_ECC_ENABLED) {
+			ecc_en = true;
+			break;
+		}
 	}
 
-	/* Check whether at least one UMC is enabled: */
-	if (umc_en_mask)
-		ecc_en = umc_en_mask == ecc_en_mask;
-	else
-		edac_dbg(0, "Node %d: No enabled UMCs.\n", nid);
-
-	edac_dbg(3, "Node %d: DRAM ECC %s.\n", nid, (ecc_en ? "enabled" : "disabled"));
+	edac_dbg(3, "Node %d: DRAM ECC %s.\n", pvt->mc_node_id, (ecc_en ? "enabled" : "disabled"));
 
-	if (!ecc_en)
-		return false;
-	else
-		return true;
+	return ecc_en;
 }
 
 static inline void