Merge tag 'edac_fixes_for_4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp

Pull EDAC fix from Borislav Petkov:
 "A fix to sb_edac correcting channel reporting on Knights Landing"

* tag 'edac_fixes_for_4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  EDAC, sb_edac: Fix channel reporting on Knights Landing

1 files changed, 11 insertions, 4 deletions

diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c
index 4fb2eb7c800d..ce0067b7a2f6 100644
--- a/drivers/edac/sb_edac.c
+++ b/drivers/edac/sb_edac.c
@@ -552,9 +552,9 @@ static const struct pci_id_table pci_dev_descr_haswell_table[] = {
 /* Knight's Landing Support */
 /*
  * KNL's memory channels are swizzled between memory controllers.
- * MC0 is mapped to CH3,5,6 and MC1 is mapped to CH0,1,2
+ * MC0 is mapped to CH3,4,5 and MC1 is mapped to CH0,1,2
  */
-#define knl_channel_remap(channel) ((channel + 3) % 6)
+#define knl_channel_remap(mc, chan) ((mc) ? (chan) : (chan) + 3)
 
 /* Memory controller, TAD tables, error injection - 2-8-0, 2-9-0 (2 of these) */
 #define PCI_DEVICE_ID_INTEL_KNL_IMC_MC       0x7840
@@ -1286,7 +1286,7 @@ static u32 knl_get_mc_route(int entry, u32 reg)
         mc = GET_BITFIELD(reg, entry*3, (entry*3)+2);
         chan = GET_BITFIELD(reg, (entry*2) + 18, (entry*2) + 18 + 1);
 
-        return knl_channel_remap(mc*3 + chan);
+        return knl_channel_remap(mc, chan);
 }
 
 /*
@@ -2997,8 +2997,15 @@ static void sbridge_mce_output_error(struct mem_ctl_info *mci,
                 } else {
                         char A = *("A");
 
-                        channel = knl_channel_remap(channel);
+                        /*
+                         * Reported channel is in range 0-2, so we can't map it
+                         * back to mc. To figure out mc we check machine check
+                         * bank register that reported this error.
+                         * bank15 means mc0 and bank16 means mc1.
+                         */
+                        channel = knl_channel_remap(m->bank == 16, channel);
                         channel_mask = 1 << channel;
+
                         snprintf(msg, sizeof(msg),
                                 "%s%s err_code:%04x:%04x channel:%d (DIMM_%c)",
                                 overflow ? " OVERFLOW" : "",