EDAC/amd64: Support more than two controllers for chip selects handling

The struct chip_select array that's used for saving chip select bases
and masks is fixed at length of two. There should be one struct
chip_select for each controller, so this array should be increased to
support systems that may have more than two controllers.

Increase the size of the struct chip_select array to eight, which is the
largest number of controllers per die currently supported on AMD
systems.

Fix number of DIMMs and Chip Select bases/masks on Family17h, because
AMD Family 17h systems support 2 DIMMs, 4 CS bases, and 2 CS masks per
channel.

Also, carve out the Family 17h+ reading of the bases/masks into a
separate function. This effectively reverts the original bases/masks
reading code to before Family 17h support was added.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20190821235938.118710-2-Yazen.Ghannam@amd.com
diff --git a/drivers/edac/amd64_edac.h b/drivers/edac/amd64_edac.h
index 8f66472..4dce6a2 100644
--- a/drivers/edac/amd64_edac.h
+++ b/drivers/edac/amd64_edac.h
@@ -96,6 +96,7 @@
 /* Hardware limit on ChipSelect rows per MC and processors per system */
 #define NUM_CHIPSELECTS			8
 #define DRAM_RANGES			8
+#define NUM_CONTROLLERS			8
 
 #define ON true
 #define OFF false
@@ -351,8 +352,8 @@ struct amd64_pvt {
 	u32 dbam0;		/* DRAM Base Address Mapping reg for DCT0 */
 	u32 dbam1;		/* DRAM Base Address Mapping reg for DCT1 */
 
-	/* one for each DCT */
-	struct chip_select csels[2];
+	/* one for each DCT/UMC */
+	struct chip_select csels[NUM_CONTROLLERS];
 
 	/* DRAM base and limit pairs F1x[78,70,68,60,58,50,48,40] */
 	struct dram_range ranges[DRAM_RANGES];