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 <avadhut.naik@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Avadhut Naik <avadhut.naik@amd.com>
Reviewed-by: Avadhut Naik <avadhut.naik@amd.com>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/20241210212054.3895697-1-avadhut.naik@amd.com

Author: bp3tk0v

drivers/edac/amd64_edac.c

@@ -3362,36 +3362,24 @@ 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