Classmaps are stored/linked in a section/array, but are each added to
the module's ddebug_table.maps list-head.

This is unnecessary; even when ddebug_attach_classmap() is handling
the builtin section (with classmaps for multiple builtin modules), its
contents are ordered, so a module's possibly multiple classmaps will
be consecutive in the section, and could be treated as a vector/block,
since both start-addy and subrange length are in the ddebug_info arg.

So this changes:

struct ddebug_class_map drops list link.

struct ddebug_table drops the maps list-head, and gets: classes &
num_classes for the start-addy, and length. num_classes is placed to
improve struct packing.

The loading: in ddebug_attach_module_classes(), replace the
for-the-modname list-add loop, with a forloop that finds the module's
subrange (start,length) of matching classmaps within the possibly
builtin classmaps vector, and saves those to the ddebug_table.

The reading/using: change list-foreach loops in ddebug_class_name() &
ddebug_find_valid_class() to walk the array from start to length.

Also:
Move #define __outvar up, above an added use in a fn-prototype.
Simplify ddebug_attach_module_classes args, ref has both addy,len.

This isn't technically a bugfix, but IMO simplifies later fixes for
the chicken-egg post-init enablement regression.

Signed-off-by: Jim Cromie <jim.cro...@gmail.com>
---
 include/linux/dynamic_debug.h |  1 -
 lib/dynamic_debug.c           | 61 ++++++++++++++++++-----------------
 2 files changed, 32 insertions(+), 30 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 41682278d2e8..bf47bcfad8e6 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -81,7 +81,6 @@ enum class_map_type {
 };
 
 struct ddebug_class_map {
-       struct list_head link;
        struct module *mod;
        const char *mod_name;   /* needed for builtins */
        const char **class_names;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 48ca1387a409..fd5296dbb40f 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -45,10 +45,11 @@ extern struct ddebug_class_map __start___dyndbg_classes[];
 extern struct ddebug_class_map __stop___dyndbg_classes[];
 
 struct ddebug_table {
-       struct list_head link, maps;
+       struct list_head link;
        const char *mod_name;
-       unsigned int num_ddebugs;
        struct _ddebug *ddebugs;
+       struct ddebug_class_map *classes;
+       unsigned int num_ddebugs, num_classes;
 };
 
 struct ddebug_query {
@@ -146,13 +147,15 @@ static void vpr_info_dq(const struct ddebug_query *query, 
const char *msg)
                  query->first_lineno, query->last_lineno, query->class_string);
 }
 
+#define __outvar /* filled by callee */
 static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table 
const *dt,
-                                                         const char 
*class_string, int *class_id)
+                                                       const char 
*class_string,
+                                                       __outvar int *class_id)
 {
        struct ddebug_class_map *map;
-       int idx;
+       int i, idx;
 
-       list_for_each_entry(map, &dt->maps, link) {
+       for (map = dt->classes, i = 0; i < dt->num_classes; i++, map++) {
                idx = match_string(map->class_names, map->length, class_string);
                if (idx >= 0) {
                        *class_id = idx + map->base;
@@ -163,7 +166,6 @@ static struct ddebug_class_map 
*ddebug_find_valid_class(struct ddebug_table cons
        return NULL;
 }
 
-#define __outvar /* filled by callee */
 /*
  * Search the tables for _ddebug's which match the given `query' and
  * apply the `flags' and `mask' to them.  Returns number of matching
@@ -1109,9 +1111,10 @@ static void *ddebug_proc_next(struct seq_file *m, void 
*p, loff_t *pos)
 
 static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug 
*dp)
 {
-       struct ddebug_class_map *map;
+       struct ddebug_class_map *map = iter->table->classes;
+       int i, nc = iter->table->num_classes;
 
-       list_for_each_entry(map, &iter->table->maps, link)
+       for (i = 0; i < nc; i++, map++)
                if (class_in_range(dp->class_id, map))
                        return map->class_names[dp->class_id - map->base];
 
@@ -1195,30 +1198,31 @@ static const struct proc_ops proc_fops = {
        .proc_write = ddebug_proc_write
 };
 
-static void ddebug_attach_module_classes(struct ddebug_table *dt,
-                                        struct ddebug_class_map *classes,
-                                        int num_classes)
+static void ddebug_attach_module_classes(struct ddebug_table *dt, struct 
_ddebug_info *di)
 {
        struct ddebug_class_map *cm;
-       int i, j, ct = 0;
+       int i, nc = 0;
 
-       for (cm = classes, i = 0; i < num_classes; i++, cm++) {
+       /*
+        * Find this module's classmaps in a subrange/wholerange of
+        * the builtin/modular classmap vector/section.  Save the start
+        * and length of the subrange at its edges.
+        */
+       for (cm = di->classes, i = 0; i < di->num_classes; i++, cm++) {
 
                if (!strcmp(cm->mod_name, dt->mod_name)) {
-
-                       v2pr_info("class[%d]: module:%s base:%d len:%d 
ty:%d\n", i,
-                                 cm->mod_name, cm->base, cm->length, 
cm->map_type);
-
-                       for (j = 0; j < cm->length; j++)
-                               v3pr_info(" %d: %d %s\n", j + cm->base, j,
-                                         cm->class_names[j]);
-
-                       list_add(&cm->link, &dt->maps);
-                       ct++;
+                       if (!nc) {
+                               v2pr_info("start subrange, class[%d]: module:%s 
base:%d len:%d ty:%d\n",
+                                         i, cm->mod_name, cm->base, 
cm->length, cm->map_type);
+                               dt->classes = cm;
+                       }
+                       nc++;
                }
        }
-       if (ct)
-               vpr_info("module:%s attached %d classes\n", dt->mod_name, ct);
+       if (nc) {
+               dt->num_classes = nc;
+               vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
+       }
 }
 
 /*
@@ -1252,10 +1256,9 @@ static int __ddebug_add_module(struct _ddebug_info *di, 
unsigned int base,
        dt->num_ddebugs = di->num_descs;
 
        INIT_LIST_HEAD(&dt->link);
-       INIT_LIST_HEAD(&dt->maps);
 
        if (di->classes && di->num_classes)
-               ddebug_attach_module_classes(dt, di->classes, di->num_classes);
+               ddebug_attach_module_classes(dt, di);
 
        mutex_lock(&ddebug_lock);
        list_add_tail(&dt->link, &ddebug_tables);
@@ -1344,8 +1347,8 @@ static void ddebug_remove_all_tables(void)
        mutex_lock(&ddebug_lock);
        while (!list_empty(&ddebug_tables)) {
                struct ddebug_table *dt = list_entry(ddebug_tables.next,
-                                                     struct ddebug_table,
-                                                     link);
+                                                    struct ddebug_table,
+                                                    link);
                ddebug_table_free(dt);
        }
        mutex_unlock(&ddebug_lock);
-- 
2.38.1

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