[PATCH v4 1/2] EDAC/amd64: Set memory type per DIMM

[Yazen Ghannam]

Current AMD systems allow mixing of DIMM types within a system. However,
DIMMs within a channel, i.e. managed by a single Unified Memory
Controller (UMC), must be of the same type.

Handle this possible configuration by checking and setting the memory
type for each individual "UMC" structure.

Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
---
Link:
https://lore.kernel.org/r/20211228200615.412999-2-yazen.ghannam@xxxxxxx

v3->v4:
* Cache dram_type in struct umc.

v2->v3:
* Change patch to properly handle systems with different DIMM types.

v1->v2:
* Was patch 3 in v1.
* Update commit message.

 drivers/edac/amd64_edac.c | 47 +++++++++++++++++++++++++++++----------
 drivers/edac/amd64_edac.h |  3 +++
 2 files changed, 38 insertions(+), 12 deletions(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index fba609ada0e6..49e384207ce0 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -1429,7 +1429,7 @@ static void __dump_misc_regs_df(struct amd64_pvt *pvt)
 		edac_dbg(1, "UMC%d x16 DIMMs present: %s\n",
 				i, (umc->dimm_cfg & BIT(7)) ? "yes" : "no");
 
-		if (pvt->dram_type == MEM_LRDDR4) {
+		if (umc->dram_type == MEM_LRDDR4) {
 			amd_smn_read(pvt->mc_node_id, umc_base + UMCCH_ADDR_CFG, &tmp);
 			edac_dbg(1, "UMC%d LRDIMM %dx rank multiply\n",
 					i, 1 << ((tmp >> 4) & 0x3));
@@ -1616,19 +1616,40 @@ static void read_dct_base_mask(struct amd64_pvt *pvt)
 	}
 }
 
+static void _determine_memory_type_df(struct amd64_umc *umc)
+{
+	if (!(umc->sdp_ctrl & UMC_SDP_INIT)) {
+		umc->dram_type = MEM_EMPTY;
+		return;
+	}
+
+	if (umc->dimm_cfg & BIT(5))
+		umc->dram_type = MEM_LRDDR4;
+	else if (umc->dimm_cfg & BIT(4))
+		umc->dram_type = MEM_RDDR4;
+	else
+		umc->dram_type = MEM_DDR4;
+}
+
+static void determine_memory_type_df(struct amd64_pvt *pvt)
+{
+	struct amd64_umc *umc;
+	u32 i;
+
+	for_each_umc(i) {
+		umc = &pvt->umc[i];
+
+		_determine_memory_type_df(umc);
+		edac_dbg(1, "  UMC%d DIMM type: %s\n", i, edac_mem_types[umc->dram_type]);
+	}
+}
+
 static void determine_memory_type(struct amd64_pvt *pvt)
 {
 	u32 dram_ctrl, dcsm;
 
-	if (pvt->umc) {
-		if ((pvt->umc[0].dimm_cfg | pvt->umc[1].dimm_cfg) & BIT(5))
-			pvt->dram_type = MEM_LRDDR4;
-		else if ((pvt->umc[0].dimm_cfg | pvt->umc[1].dimm_cfg) & BIT(4))
-			pvt->dram_type = MEM_RDDR4;
-		else
-			pvt->dram_type = MEM_DDR4;
-		return;
-	}
+	if (pvt->umc)
+		return determine_memory_type_df(pvt);
 
 	switch (pvt->fam) {
 	case 0xf:
@@ -3452,7 +3473,9 @@ static void read_mc_regs(struct amd64_pvt *pvt)
 	read_dct_base_mask(pvt);
 
 	determine_memory_type(pvt);
-	edac_dbg(1, "  DIMM type: %s\n", edac_mem_types[pvt->dram_type]);
+
+	if (!pvt->umc)
+		edac_dbg(1, "  DIMM type: %s\n", edac_mem_types[pvt->dram_type]);
 
 	determine_ecc_sym_sz(pvt);
 }
@@ -3548,7 +3571,7 @@ static int init_csrows_df(struct mem_ctl_info *mci)
 					pvt->mc_node_id, cs);
 
 			dimm->nr_pages = get_csrow_nr_pages(pvt, umc, cs);
-			dimm->mtype = pvt->dram_type;
+			dimm->mtype = pvt->umc[umc].dram_type;
 			dimm->edac_mode = edac_mode;
 			dimm->dtype = dev_type;
 			dimm->grain = 64;
diff --git a/drivers/edac/amd64_edac.h b/drivers/edac/amd64_edac.h
index 352bda9803f6..09ad28299c57 100644
--- a/drivers/edac/amd64_edac.h
+++ b/drivers/edac/amd64_edac.h
@@ -344,6 +344,9 @@ struct amd64_umc {
 	u32 sdp_ctrl;		/* SDP Control reg */
 	u32 ecc_ctrl;		/* DRAM ECC Control reg */
 	u32 umc_cap_hi;		/* Capabilities High reg */
+
+	/* cache the dram_type */
+	enum mem_type dram_type;
 };
 
 struct amd64_pvt {
-- 
2.25.1