edac: Create a dimm struct and move the labels into it

The way a DIMM is currently represented implies that they're
linked into a per-csrow struct. However, some drivers don't see
csrows, as they're ridden behind some chip like the AMB's
on FBDIMM's, for example.

This forced drivers to fake^Wvirtualize a csrow struct, and to create
a mess under csrow/channel original's concept.

Move the DIMM labels into a per-DIMM struct, and add there
the real location of the socket, in terms of csrow/channel.
Latter patches will modify the location to properly represent the
memory architecture.

All other drivers will use a per-csrow type of location.
Some of those drivers will require a latter conversion, as
they also fake the csrows internally.

TODO: While this patch doesn't change the existing behavior, on
csrows-based memory controllers, a csrow/channel pair points to a memory
rank. There's a known bug at the EDAC core that allows having different
labels for the same DIMM, if it has more than one rank. A latter patch
is need to merge the several ranks for a DIMM into the same dimm_info
struct, in order to avoid having different labels for the same DIMM.

The edac_mc_alloc() will now contain a per-dimm initialization loop that
will be changed by latter patches in order to match other types of
memory architectures.

Reviewed-by: Aristeu Rozanski <arozansk@redhat.com>
Reviewed-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Doug Thompson <norsk5@yahoo.com>
Cc: Ranganathan Desikan <ravi@jetztechnologies.com>
Cc: "Arvind R." <arvino55@gmail.com>
Cc: "Niklas Söderlund" <niklas.soderlund@ericsson.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 23 insertions, 5 deletions

diff --git a/include/linux/edac.h b/include/linux/edac.h
index c621d762bb2c..52bceca85e63 100644
--- a/include/linux/edac.h
+++ b/include/linux/edac.h
@@ -312,23 +312,34 @@ enum scrub_type {
  * PS - I enjoyed writing all that about as much as you enjoyed reading it.
  */
 
+/* FIXME: add a per-dimm ce error count */
+struct dimm_info {
+        char label[EDAC_MC_LABEL_LEN + 1];      /* DIMM label on motherboard */
+        unsigned memory_controller;
+        unsigned csrow;
+        unsigned csrow_channel;
+};
+
 /**
  * struct rank_info - contains the information for one DIMM rank
  *
  * @chan_idx:   channel number where the rank is (typically, 0 or 1)
  * @ce_count:   number of correctable errors for this rank
- * @label:      DIMM label. Different ranks for the same DIMM should be
- *              filled, on userspace, with the same label.
- *              FIXME: The core currently won't enforce it.
  * @csrow:      A pointer to the chip select row structure (the parent
  *              structure). The location of the rank is given by
  *              the (csrow->csrow_idx, chan_idx) vector.
+ * @dimm:       A pointer to the DIMM structure, where the DIMM label
+ *              information is stored.
+ *
+ * FIXME: Currently, the EDAC core model will assume one DIMM per rank.
+ *        This is a bad assumption, but it makes this patch easier. Later
+ *        patches in this series will fix this issue.
  */
 struct rank_info {
         int chan_idx;
         u32 ce_count;
-        char label[EDAC_MC_LABEL_LEN + 1];
-        struct csrow_info *csrow;       /* the parent */
+        struct csrow_info *csrow;
+        struct dimm_info *dimm;
 };
 
 struct csrow_info {
@@ -428,6 +439,13 @@ struct mem_ctl_info {
         int mc_idx;
         int nr_csrows;
         struct csrow_info *csrows;
+
+        /*
+         * DIMM info. Will eventually remove the entire csrows_info some day
+         */
+        unsigned nr_dimms;
+        struct dimm_info *dimms;
+
         /*
          * FIXME - what about controllers on other busses? - IDs must be
          * unique.  dev pointer should be sufficiently unique, but