edac: reduce stack pressure by using a pre-allocated buffer

The number of variables at the stack is too big.
Reduces the stack usage by using a pre-allocated error
buffer.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 56 insertions, 0 deletions

diff --git a/include/linux/edac.h b/include/linux/edac.h
index ff18efc754f3..096b7fcdf484 100644
--- a/include/linux/edac.h
+++ b/include/linux/edac.h
@@ -47,8 +47,18 @@ static inline void opstate_init(void)
         return;
 }
 
+/* Max length of a DIMM label*/
 #define EDAC_MC_LABEL_LEN       31
 
+/* Maximum size of the location string */
+#define LOCATION_SIZE 80
+
+/* Defines the maximum number of labels that can be reported */
+#define EDAC_MAX_LABELS         8
+
+/* String used to join two or more labels */
+#define OTHER_LABEL " or "
+
 /**
  * enum dev_type - describe the type of memory DRAM chips used at the stick
  * @DEV_UNKNOWN:        Can't be determined, or MC doesn't support detect it
@@ -553,6 +563,46 @@ struct errcount_attribute_data {
         int layer0, layer1, layer2;
 };
 
+/**
+ * edac_raw_error_desc - Raw error report structure
+ * @grain:                      minimum granularity for an error report, in bytes
+ * @error_count:                number of errors of the same type
+ * @top_layer:                  top layer of the error (layer[0])
+ * @mid_layer:                  middle layer of the error (layer[1])
+ * @low_layer:                  low layer of the error (layer[2])
+ * @page_frame_number:          page where the error happened
+ * @offset_in_page:             page offset
+ * @syndrome:                   syndrome of the error (or 0 if unknown or if
+ *                              the syndrome is not applicable)
+ * @msg:                        error message
+ * @location:                   location of the error
+ * @label:                      label of the affected DIMM(s)
+ * @other_detail:               other driver-specific detail about the error
+ * @enable_per_layer_report:    if false, the error affects all layers
+ *                              (typically, a memory controller error)
+ */
+struct edac_raw_error_desc {
+        /*
+         * NOTE: everything before grain won't be cleaned by
+         * edac_raw_error_desc_clean()
+         */
+        char location[LOCATION_SIZE];
+        char label[(EDAC_MC_LABEL_LEN + 1 + sizeof(OTHER_LABEL)) * EDAC_MAX_LABELS];
+        long grain;
+
+        /* the vars below and grain will be cleaned on every new error report */
+        u16 error_count;
+        int top_layer;
+        int mid_layer;
+        int low_layer;
+        unsigned long page_frame_number;
+        unsigned long offset_in_page;
+        unsigned long syndrome;
+        const char *msg;
+        const char *other_detail;
+        bool enable_per_layer_report;
+};
+
 /* MEMORY controller information structure
  */
 struct mem_ctl_info {
@@ -660,6 +710,12 @@ struct mem_ctl_info {
         /* work struct for this MC */
         struct delayed_work work;
 
+        /*
+         * Used to report an error - by being at the global struct
+         * makes the memory allocated by the EDAC core
+         */
+        struct edac_raw_error_desc error_desc;
+
         /* the internal state of this controller instance */
         int op_state;