EDAC/amd64: Split read_mc_regs() into dct/umc functions

Call them from their respective hw_info_get() paths.

ECC symbol size is not needed on UMC systems, so determine_ecc_sym_sz()
is left out of the UMC path. Do not save TOP_MEM* values on modern
controllers because they're not needed there (read: they were used only
for debugging, if anything).

  [ Yazen: rebased/reworked patch and reworded commit message. ]
Signed-off-by: Muralidhara M K <muralidhara.mk@amd.com>
Co-developed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Co-developed-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230127170419.1824692-16-yazen.ghannam@amd.com

drivers/edac/amd64_edac.c

@@ -3089,7 +3089,7 @@ static void determine_ecc_sym_sz(struct amd64_pvt *pvt)
 /*
  * Retrieve the hardware registers of the memory controller.
  */
-static void __read_mc_regs_df(struct amd64_pvt *pvt)
+static void umc_read_mc_regs(struct amd64_pvt *pvt)
 {
 	u8 nid = pvt->mc_node_id;
 	struct amd64_umc *umc;
@@ -3113,7 +3113,7 @@ static void __read_mc_regs_df(struct amd64_pvt *pvt)
  * Retrieve the hardware registers of the memory controller (this includes the
  * 'Address Map' and 'Misc' device regs)
  */
-static void read_mc_regs(struct amd64_pvt *pvt)
+static void dct_read_mc_regs(struct amd64_pvt *pvt)
 {
 	unsigned int range;
 	u64 msr_val;
@@ -3134,12 +3134,6 @@ static void read_mc_regs(struct amd64_pvt *pvt)
 		edac_dbg(0, "  TOP_MEM2 disabled\n");
 	}
 
-	if (pvt->umc) {
-		__read_mc_regs_df(pvt);
-
-		goto skip;
-	}
-
 	amd64_read_pci_cfg(pvt->F3, NBCAP, &pvt->nbcap);
 
 	read_dram_ctl_register(pvt);
@@ -3180,9 +3174,6 @@ static void read_mc_regs(struct amd64_pvt *pvt)
 		amd64_read_dct_pci_cfg(pvt, 1, DCHR0, &pvt->dchr1);
 	}
 
-skip:
-
-
 	determine_ecc_sym_sz(pvt);
 }
 
@@ -3658,7 +3649,7 @@ static int dct_hw_info_get(struct amd64_pvt *pvt)
 
 	dct_prep_chip_selects(pvt);
 	dct_read_base_mask(pvt);
-	read_mc_regs(pvt);
+	dct_read_mc_regs(pvt);
 	dct_determine_memory_type(pvt);
 
 	return 0;
@@ -3672,7 +3663,7 @@ static int umc_hw_info_get(struct amd64_pvt *pvt)
 
 	umc_prep_chip_selects(pvt);
 	umc_read_base_mask(pvt);
-	read_mc_regs(pvt);
+	umc_read_mc_regs(pvt);
 	umc_determine_memory_type(pvt);
 
 	return 0;