EDAC, sb_edac: Fix missing DIMM sysfs entries with KNL SNC2/SNC4 mode

BugLink: http://bugs.launchpad.net/bugs/1743856
When figuring out the size of the DIMMs and the cluster mode is SNC2 or SNC4 the
current algorithm ignores the contribution of some of the channels resulting in
EDAC never knowing of the existence of some DIMMs attached to such channels (thus
sysfs is not populated).

Instead of selectively iterating from 0 to interlv_ways when looking for all the
participants in the interleave, do an exhaustive search and iterate from 0 to
KNL_MAX_CHANNELS. The algorithm is already smart enough to consider participants
only one time.

This works fine in all KNL cluster modes and even when there are missing DIMMs
as the contribution of those channels is 0.

Signed-off-by: Luis Felipe Sandoval Castro <luis.felipe.sandoval.castro@intel.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: arozansk@redhat.com
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: qiuxu.zhuo@intel.com
Link: http://lkml.kernel.org/r/1506606882-90521-1-git-send-email-luis.felipe.sandoval.castro@intel.com
Signed-off-by: Borislav Petkov <bp@suse.de>
(cherry picked from commit 24281a2f4ca569d44e44e4cbc500cf08e7bb4c36)
Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c
index 7a3b201d51df0bd15ecbb66d018c19a3d69a9c83..5c3e707ff3fcb54f9479021c12da5dff36c9d6a5 100644 (file)
--- a/drivers/edac/sb_edac.c
+++ b/drivers/edac/sb_edac.c
@@ -1311,9 +1311,7 @@ static int knl_get_dimm_capacity(struct sbridge_pvt *pvt, u64 *mc_sizes)
        int cur_reg_start;
        int mc;
        int channel;
-       int way;
        int participants[KNL_MAX_CHANNELS];
-       int participant_count = 0;
 
        for (i = 0; i < KNL_MAX_CHANNELS; i++)
                mc_sizes[i] = 0;
@@ -1488,21 +1486,14 @@ static int knl_get_dimm_capacity(struct sbridge_pvt *pvt, u64 *mc_sizes)
                 * this channel mapped to the given target?
                 */
                for (channel = 0; channel < KNL_MAX_CHANNELS; channel++) {
-                       for (way = 0; way < intrlv_ways; way++) {
-                               int target;
-                               int cha;
-
-                               if (KNL_MOD3(dram_rule))
-                                       target = way;
-                               else
-                                       target = 0x7 & sad_pkg(
-                               pvt->info.interleave_pkg, interleave_reg, way);
+                       int target;
+                       int cha;
 
+                       for (target = 0; target < KNL_MAX_CHANNELS; target++) {
                                for (cha = 0; cha < KNL_MAX_CHAS; cha++) {
                                        if (knl_get_mc_route(target,
                                                mc_route_reg[cha]) == channel
                                                && !participants[channel]) {
-                                               participant_count++;
                                                participants[channel] = 1;
                                                break;
                                        }
@@ -1510,10 +1501,6 @@ static int knl_get_dimm_capacity(struct sbridge_pvt *pvt, u64 *mc_sizes)
                        }
                }
 
-               if (participant_count != intrlv_ways)
-                       edac_dbg(0, "participant_count (%d) != interleave_ways (%d): DIMM size may be incorrect\n",
-                               participant_count, intrlv_ways);
-
                for (channel = 0; channel < KNL_MAX_CHANNELS; channel++) {
                        mc = knl_channel_mc(channel);
                        if (participants[channel]) {