EDAC/amd64: Support asymmetric dual-rank DIMMs

Future AMD systems will support asymmetric dual-rank DIMMs. These are
DIMMs where the ranks are of different sizes.

The even rank will use the Primary Even Chip Select registers and the
odd rank will use the Secondary Odd Chip Select registers.

Recognize if a Secondary Odd Chip Select is being used. Use the
Secondary Odd Address Mask when calculating the chip select size.

 [ bp: move csrow_sec_enabled() to the header, fix CS_ODD define and
   tone-down the capitalized words spelling. ]

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/20190821235938.118710-8-Yazen.Ghannam@amd.com

2 files changed, 15 insertions, 4 deletions

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index 23251bba8eb6..18ba9c898389 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -790,9 +790,11 @@ static void debug_dump_dramcfg_low(struct amd64_pvt *pvt, u32 dclr, int chan)
 
 #define CS_EVEN_PRIMARY         BIT(0)
 #define CS_ODD_PRIMARY          BIT(1)
+#define CS_EVEN_SECONDARY       BIT(2)
+#define CS_ODD_SECONDARY        BIT(3)
 
-#define CS_EVEN                 CS_EVEN_PRIMARY
-#define CS_ODD                  CS_ODD_PRIMARY
+#define CS_EVEN                 (CS_EVEN_PRIMARY | CS_EVEN_SECONDARY)
+#define CS_ODD                  (CS_ODD_PRIMARY | CS_ODD_SECONDARY)
 
 static int f17_get_cs_mode(int dimm, u8 ctrl, struct amd64_pvt *pvt)
 {
@@ -804,6 +806,10 @@ static int f17_get_cs_mode(int dimm, u8 ctrl, struct amd64_pvt *pvt)
         if (csrow_enabled(2 * dimm + 1, ctrl, pvt))
                 cs_mode |= CS_ODD_PRIMARY;
 
+        /* Asymmetric dual-rank DIMM support. */
+        if (csrow_sec_enabled(2 * dimm + 1, ctrl, pvt))
+                cs_mode |= CS_ODD_SECONDARY;
+
         return cs_mode;
 }
 
@@ -1600,7 +1606,11 @@ static int f17_addr_mask_to_cs_size(struct amd64_pvt *pvt, u8 umc,
          */
         dimm = csrow_nr >> 1;
 
-        addr_mask_orig = pvt->csels[umc].csmasks[dimm];
+        /* Asymmetric dual-rank DIMM support. */
+        if ((csrow_nr & 1) && (cs_mode & CS_ODD_SECONDARY))
+                addr_mask_orig = pvt->csels[umc].csmasks_sec[dimm];
+        else
+                addr_mask_orig = pvt->csels[umc].csmasks[dimm];
 
         /*
          * The number of zero bits in the mask is equal to the number of bits
diff --git a/drivers/edac/amd64_edac.h b/drivers/edac/amd64_edac.h
index 68f12de6e654..8addc4d95577 100644
--- a/drivers/edac/amd64_edac.h
+++ b/drivers/edac/amd64_edac.h
@@ -169,7 +169,8 @@
 #define DCSM0                           0x60
 #define DCSM1                           0x160
 
-#define csrow_enabled(i, dct, pvt)      ((pvt)->csels[(dct)].csbases[(i)] & DCSB_CS_ENABLE)
+#define csrow_enabled(i, dct, pvt)      ((pvt)->csels[(dct)].csbases[(i)]     & DCSB_CS_ENABLE)
+#define csrow_sec_enabled(i, dct, pvt)  ((pvt)->csels[(dct)].csbases_sec[(i)] & DCSB_CS_ENABLE)
 
 #define DRAM_CONTROL                    0x78