EDAC, amd64: Determine EDAC capabilities on Fam17h systems

We need to determine the EDAC capabilities from all UMCs on the node. We
should only check UMCs that are enabled and make sure they all agree.
Signed-off-by: NYazen Ghannam <Yazen.Ghannam@amd.com>
Cc: Aravind Gopalakrishnan <aravindksg.lkml@gmail.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/1479423463-8536-15-git-send-email-Yazen.Ghannam@amd.comSigned-off-by: NBorislav Petkov <bp@suse.de>

drivers/edac/amd64_edac.c

@@ -715,15 +715,33 @@ static int get_channel_from_ecc_syndrome(struct mem_ctl_info *, u16);
  */
 static unsigned long determine_edac_cap(struct amd64_pvt *pvt)
 {
-	u8 bit;
 	unsigned long edac_cap = EDAC_FLAG_NONE;
+	u8 bit;
+
+	if (pvt->umc) {
+		u8 i, umc_en_mask = 0, dimm_ecc_en_mask = 0;
+
+		for (i = 0; i < NUM_UMCS; i++) {
+			if (!(pvt->umc[i].sdp_ctrl & UMC_SDP_INIT))
+				continue;
 
+			umc_en_mask |= BIT(i);
+
+			/* UMC Configuration bit 12 (DimmEccEn) */
+			if (pvt->umc[i].umc_cfg & BIT(12))
+				dimm_ecc_en_mask |= BIT(i);
+		}
+
+		if (umc_en_mask == dimm_ecc_en_mask)
+			edac_cap = EDAC_FLAG_SECDED;
+	} else {
 		bit = (pvt->fam > 0xf || pvt->ext_model >= K8_REV_F)
 			? 19
 			: 17;
 
 		if (pvt->dclr0 & BIT(bit))
 			edac_cap = EDAC_FLAG_SECDED;
+	}
 
 	return edac_cap;
 }