[PATCH v5 00/22] fix DRM_USE_DYNAMIC_DEBUG regression

[PATCH v5 00/22] fix DRM_USE_DYNAMIC_DEBUG regression

[Jim Cromie]

Hi Jason, Daniel

Since patchwork puked on v5 just sent, Im calling this v5b.
Its also on github

remote: Create a pull request for 'dd-fix-5b' on GitHub by visiting:
remote:      https://github.com/jimc/linux/pull/new/dd-fix-5b
remote: 
To github.com:jimc/linux.git
 * [new branch]                dd-fix-5b -> dd-fix-5b

This is V5, Im hoping to land this one.
 patchwork will probably call this set v3
 113361	fix DRM_USE_DYNAMIC_DEBUG regression - revs 1,2
 111652	DRM_USE_DYNAMIC_DEBUG regression - older, also 2 revs

It (patch 14 mainly):
 Fixes: aad0214f3026 ("dyndbg: add DECLARE_DYNDBG_CLASSMAP macro")
 Fixes: f158936b60a7 ("drm: POC drm on dyndbg - use in core, 2 helpers, 3 drivers.")
 Ref: commit bb2ff6c27bc9 ("drm: Disable dynamic debug as broken")

It replaces DECLARE_DYNDBG_CLASSMAP macro with 2 new ones;
DYNDBG_CLASSMAP_DEFINE/_USE, and invokes them from drm.ko and drivers
respectively.  A new __dyndbg_class_users section contains each
driver's _USE; dyndbg scans it at driver-module load, finds drm.debug,
and applies it to the driver's class'd prdbgs.

The code it fixes went in here:
https://lore.kernel.org/lkml/Yy7%2F6oTBW2lqVSK1@kroah.com/

then Ref: effectively marked DRM_USE_DYNAMIC_DEBUG=y as broken

and https://lore.kernel.org/lkml/Y3XUrOGAV4I7bB3M@kroah.com/
GregKH opined:
This should go through the drm tree now.  The rest probably should also
go that way and not through my tree as well.

While most of this patchset's churn is still in lib/, DRM is the real
user for all this classmap stuff, and the real acceptance test is in
DRM CI.  Hopefully it won't fall over in BAT.

However, theres also a dyndbg patch to add -s flag, I havent seen it
lately, but it might have a nominal conflict.

I'll happily take reviews/Acks/tested-bys, grumpily breakage reports.
And some landing instructions, wind-speed, runway assignment, etc from the Tower.

theres also a few drive-by checkpatch tweaks.
13 fixes a warning that 14 gets about vmlinux.lds.h declared linker-symbols.


Jim Cromie (22):
  drm: use correct ccflags-y syntax
  test-dyndbg: fixup CLASSMAP usage error
  dyndbg: make ddebug_class_param union members same size
  dyndbg: replace classmap list with a vector
  dyndbg: ddebug_apply_class_bitmap - add module arg, select on it
  dyndbg: split param_set_dyndbg_classes to module/wrapper fns
  dyndbg: drop NUM_TYPE_ARRAY
  dyndbg: reduce verbose/debug clutter
  dyndbg: silence debugs with no-change updates
  dyndbg: tighten ddebug_class_name() 1st arg type
  dyndbg: tighten fn-sig of ddebug_apply_class_bitmap
  dyndbg-API: remove DD_CLASS_TYPE_(DISJOINT|LEVEL)_NAMES and code
  checkpatch: file-scoped extern special case for linker-symbol
  dyndbg-API: fix CONFIG_DRM_USE_DYNAMIC_DEBUG regression
  dyndbg: add for_each_boxed_vector
  dyndbg: refactor ddebug_classparam_clamp_input
  dyndbg-API: promote DYNDBG_CLASSMAP_PARAM to API
  dyndbg-test: build it with just CONFIG_DYNAMIC_DEBUG_CORE
  drm: restore CONFIG_DRM_USE_DYNAMIC_DEBUG un-BROKEN
  drm-drivers: DRM_CLASSMAP_USE in 2nd batch of drivers, helpers
  dyndbg-doc: add classmap info to howto
  checkpatch: reword long-line warn about commit-msg

 .../admin-guide/dynamic-debug-howto.rst       |  64 ++-
 MAINTAINERS                                   |   2 +-
 drivers/gpu/drm/Kconfig                       |   3 +-
 drivers/gpu/drm/Makefile                      |   3 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c       |  12 +-
 drivers/gpu/drm/display/drm_dp_helper.c       |  12 +-
 drivers/gpu/drm/drm_crtc_helper.c             |  12 +-
 drivers/gpu/drm/drm_gem_shmem_helper.c        |   2 +
 drivers/gpu/drm/drm_print.c                   |  35 +-
 drivers/gpu/drm/gud/gud_drv.c                 |   2 +
 drivers/gpu/drm/i915/i915_params.c            |  12 +-
 drivers/gpu/drm/mgag200/mgag200_drv.c         |   2 +
 drivers/gpu/drm/nouveau/nouveau_drm.c         |  12 +-
 drivers/gpu/drm/qxl/qxl_drv.c                 |   2 +
 drivers/gpu/drm/radeon/radeon_drv.c           |   2 +
 drivers/gpu/drm/udl/udl_main.c                |   2 +
 drivers/gpu/drm/vkms/vkms_drv.c               |   2 +
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c           |   2 +
 include/asm-generic/vmlinux.lds.h             |   1 +
 include/drm/drm_print.h                       |  12 +-
 include/linux/dynamic_debug.h                 | 113 +++--
 kernel/module/main.c                          |   3 +
 lib/Kconfig.debug                             |  10 +-
 lib/Makefile                                  |   4 +-
 lib/dynamic_debug.c                           | 406 +++++++++++-------
 lib/test_dynamic_debug.c                      | 127 +++---
 lib/test_dynamic_debug_submod.c               |  10 +
 scripts/checkpatch.pl                         |  22 +-
 28 files changed, 550 insertions(+), 341 deletions(-)
 create mode 100644 lib/test_dynamic_debug_submod.c

-- 
2.41.0

[PATCH v5 01/23] drm: use correct ccflags-y syntax

[Jim Cromie]

Incorrect CFLAGS- usage failed to add -DDYNAMIC_DEBUG_MODULE,
which broke builds with:

CONFIG_DRM_USE_DYNAMIC_DEBUG=y
CONFIG_DYNAMIC_DEBUG_CORE=y
but without DYNAMIC_DEBUG

Nobody noticed because a larger regression emerged.

Also add subdir-ccflags so that all drivers pick up the addition.

Fixes: 84ec67288c10 ("drm_print: wrap drm_*_dbg in dyndbg descriptor factory macro")
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 drivers/gpu/drm/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index a33257d2bc7f..670bf046019e 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -3,7 +3,8 @@
 # Makefile for the drm device driver.  This driver provides support for the
 # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
 
-CFLAGS-$(CONFIG_DRM_USE_DYNAMIC_DEBUG)	+= -DDYNAMIC_DEBUG_MODULE
+ccflags-$(CONFIG_DRM_USE_DYNAMIC_DEBUG)		+= -DDYNAMIC_DEBUG_MODULE
+subdir-ccflags-$(CONFIG_DRM_USE_DYNAMIC_DEBUG)	+= -DDYNAMIC_DEBUG_MODULE
 
 drm-y := \
 	drm_aperture.o \
-- 
2.41.0

[PATCH v5 02/23] test-dyndbg: fixup CLASSMAP usage error

[Jim Cromie]

more careful reading of test output reveals:

lib/test_dynamic_debug.c:103 [test_dynamic_debug]do_cats =pmf "doing categories\n"
lib/test_dynamic_debug.c:105 [test_dynamic_debug]do_cats =p "LOW msg\n" class:MID
lib/test_dynamic_debug.c:106 [test_dynamic_debug]do_cats =p "MID msg\n" class:HI
lib/test_dynamic_debug.c:107 [test_dynamic_debug]do_cats =_ "HI msg\n" class unknown, _id:13

That last line is wrong, the HI class is declared.

But the enum's 1st val (explicitly initialized) was wrong; it must be
_base, not _base+1 (a DECLARE_DYNDBG_CLASSMAP[1] param).  So the last
enumeration exceeded the range of mapped class-id's, which triggered
the "class unknown" report.  I intentionally coded in an error, but
forgot to verify its detection and remove it.

RFC:

This patch fixes a bad usage of DECLARE_DYNDBG_CLASSMAP(), showing
that it is too error-prone.  As noted in test-mod comments:

 * Using the CLASSMAP api:
 * - classmaps must have corresponding enum
 * - enum symbols must match/correlate with class-name strings in the map.
 * - base must equal enum's 1st value
 * - multiple maps must set their base to share the 0-62 class_id space !!
 *   (build-bug-on tips welcome)

Those shortcomings could largely be fixed with a __stringify_list
(which doesn't exist,) used in DECLARE_DYNDBG_CLASSMAP to stringify
__VA_ARGS__.  Then, API would accept DRM_UT_* values literally; all
the categories, in order, and not their stringifications, which
created all the usage complications above.

[1] name changes later to DYNDBG_CLASSMAP_DEFINE

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/test_dynamic_debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 8dd250ad022b..a01f0193a419 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -75,7 +75,7 @@ DD_SYS_WRAP(disjoint_bits, p);
 DD_SYS_WRAP(disjoint_bits, T);
 
 /* symbolic input, independent bits */
-enum cat_disjoint_names { LOW = 11, MID, HI };
+enum cat_disjoint_names { LOW = 10, MID, HI };
 DECLARE_DYNDBG_CLASSMAP(map_disjoint_names, DD_CLASS_TYPE_DISJOINT_NAMES, 10,
 			"LOW", "MID", "HI");
 DD_SYS_WRAP(disjoint_names, p);
-- 
2.41.0

[PATCH v5 03/23] dyndbg: make ddebug_class_param union members same size

[Jim Cromie]

struct ddebug_class_param keeps a ref to the state-storage of the
param, make both flavors use the same unsigned long under-type.
ISTM this is simpler and safer.

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

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 061dd84d09f3..dc41e70dc2e1 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -122,7 +122,7 @@ struct _ddebug_info {
 struct ddebug_class_param {
 	union {
 		unsigned long *bits;
-		unsigned int *lvl;
+		unsigned long *lvl;
 	};
 	char flags[8];
 	const struct ddebug_class_map *map;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index fdd6d9800a70..22a3182bf89f 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -795,7 +795,7 @@ int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
 
 	case DD_CLASS_TYPE_LEVEL_NAMES:
 	case DD_CLASS_TYPE_LEVEL_NUM:
-		return scnprintf(buffer, PAGE_SIZE, "%d\n", *dcp->lvl);
+		return scnprintf(buffer, PAGE_SIZE, "%ld\n", *dcp->lvl);
 	default:
 		return -1;
 	}
-- 
2.41.0

[PATCH v5 04/23] dyndbg: replace classmap list with a vector

[Jim Cromie]

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-head link.

struct ddebug_table drops the list-head maps, and gets: classes &
num_classes for the start-addy and num_classes, 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.

no functional changes

Signed-off-by: Jim Cromie <jim.cromie@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 dc41e70dc2e1..596d0664c29f 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 22a3182bf89f..b4b6c5111315 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
@@ -1107,9 +1109,10 @@ 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];
 
@@ -1193,30 +1196,31 @@ 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);
+	}
 }
 
 /*
@@ -1249,10 +1253,9 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 	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);
@@ -1365,8 +1368,8 @@ 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);
-- 
2.41.0

[PATCH v5 05/23] dyndbg: ddebug_apply_class_bitmap - add module arg, select on it

[Jim Cromie]

Add query_module param to ddebug_apply_class_bitmap().  This allows
its caller to update just one module, or all (as currently).  We'll
use this later to propagate drm.debug to each USEr as they're
modprobed.

No functional change.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---

after `modprobe i915`, heres the module dependencies,
though not all on drm.debug.

bash-5.2# lsmod
Module                  Size  Used by
i915                 3133440  0
drm_buddy              20480  1 i915
ttm                    90112  1 i915
i2c_algo_bit           16384  1 i915
video                  61440  1 i915
wmi                    32768  1 video
drm_display_helper    200704  1 i915
drm_kms_helper        208896  2 drm_display_helper,i915
drm                   606208  5 drm_kms_helper,drm_display_helper,drm_buddy,i915,ttm
cec                    57344  2 drm_display_helper,i915
---
 lib/dynamic_debug.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index b4b6c5111315..d875c4fa5335 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -600,7 +600,8 @@ static int ddebug_exec_queries(char *query, const char *modname)
 
 /* apply a new bitmap to the sys-knob's current bit-state */
 static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
-				     unsigned long *new_bits, unsigned long *old_bits)
+				     unsigned long *new_bits, unsigned long *old_bits,
+				     const char *query_modname)
 {
 #define QUERY_SIZE 128
 	char query[QUERY_SIZE];
@@ -608,7 +609,8 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 	int matches = 0;
 	int bi, ct;
 
-	v2pr_info("apply: 0x%lx to: 0x%lx\n", *new_bits, *old_bits);
+	v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits, *old_bits,
+		  query_modname ?: "");
 
 	for (bi = 0; bi < map->length; bi++) {
 		if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
@@ -617,12 +619,15 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 		snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
 			 test_bit(bi, new_bits) ? '+' : '-', dcp->flags);
 
-		ct = ddebug_exec_queries(query, NULL);
+		ct = ddebug_exec_queries(query, query_modname);
 		matches += ct;
 
 		v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
 			  ct, map->class_names[bi], *new_bits);
 	}
+	v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits, *old_bits,
+		  query_modname ?: "");
+
 	return matches;
 }
 
@@ -678,7 +683,7 @@ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_pa
 				continue;
 			}
 			curr_bits ^= BIT(cls_id);
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits);
+			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits, NULL);
 			*dcp->bits = curr_bits;
 			v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
 				  map->class_names[cls_id]);
@@ -688,7 +693,7 @@ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_pa
 			old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 			curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));
 
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits);
+			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits, NULL);
 			*dcp->lvl = (cls_id + (wanted ? 1 : 0));
 			v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
 				  map->class_names[cls_id], old_bits, curr_bits);
@@ -751,7 +756,7 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
 			inrep &= CLASSMAP_BITMASK(map->length);
 		}
 		v2pr_info("bits:%lx > %s\n", inrep, KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits);
+		totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits, NULL);
 		*dcp->bits = inrep;
 		break;
 	case DD_CLASS_TYPE_LEVEL_NUM:
@@ -764,7 +769,7 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
 		old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 		new_bits = CLASSMAP_BITMASK(inrep);
 		v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits);
+		totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits, NULL);
 		*dcp->lvl = inrep;
 		break;
 	default:
-- 
2.41.0

[PATCH v5 06/23] dyndbg: split param_set_dyndbg_classes to module/wrapper fns

[Jim Cromie]

rename param_set_dyndbg_classes: add _module_ name & arg, old name is
wrapper to new.  New arg allows caller to specify that only one module
is affected by a prdbgs update.

Outer fn preserves kernel_param interface, passing NULL to inner fn.
This selectivity will be used later to narrow the scope of changes
made.

no functional change.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 37 ++++++++++++++++++++++---------------
 1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index d875c4fa5335..550d380f7690 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -707,18 +707,9 @@ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_pa
 	return 0;
 }
 
-/**
- * param_set_dyndbg_classes - class FOO >control
- * @instr: string echo>d to sysfs, input depends on map_type
- * @kp:    kp->arg has state: bits/lvl, map, map_type
- *
- * Enable/disable prdbgs by their class, as given in the arguments to
- * DECLARE_DYNDBG_CLASSMAP.  For LEVEL map-types, enforce relative
- * levels by bitpos.
- *
- * Returns: 0 or <0 if error.
- */
-int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
+static int param_set_dyndbg_module_classes(const char *instr,
+					   const struct kernel_param *kp,
+					   const char *modnm)
 {
 	const struct ddebug_class_param *dcp = kp->arg;
 	const struct ddebug_class_map *map = dcp->map;
@@ -755,8 +746,8 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
 				KP_NAME(kp), inrep, CLASSMAP_BITMASK(map->length));
 			inrep &= CLASSMAP_BITMASK(map->length);
 		}
-		v2pr_info("bits:%lx > %s\n", inrep, KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits, NULL);
+		v2pr_info("bits:0x%lx > %s.%s\n", inrep, modnm ?: "*", KP_NAME(kp));
+		totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits, modnm);
 		*dcp->bits = inrep;
 		break;
 	case DD_CLASS_TYPE_LEVEL_NUM:
@@ -769,7 +760,7 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
 		old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 		new_bits = CLASSMAP_BITMASK(inrep);
 		v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits, NULL);
+		totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits, modnm);
 		*dcp->lvl = inrep;
 		break;
 	default:
@@ -778,6 +769,22 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
 	vpr_info("%s: total matches: %d\n", KP_NAME(kp), totct);
 	return 0;
 }
+
+/**
+ * param_set_dyndbg_classes - class FOO >control
+ * @instr: string echo>d to sysfs, input depends on map_type
+ * @kp:    kp->arg has state: bits/lvl, map, map_type
+ *
+ * Enable/disable prdbgs by their class, as given in the arguments to
+ * DECLARE_DYNDBG_CLASSMAP.  For LEVEL map-types, enforce relative
+ * levels by bitpos.
+ *
+ * Returns: 0 or <0 if error.
+ */
+int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
+{
+	return param_set_dyndbg_module_classes(instr, kp, NULL);
+}
 EXPORT_SYMBOL(param_set_dyndbg_classes);
 
 /**
-- 
2.41.0

[PATCH v5 07/23] dyndbg: drop NUM_TYPE_ARRAY

[Jim Cromie]

ARRAY_SIZE works here, since array decl is complete.

no functional change

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 596d0664c29f..719c5b6ad0f9 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -104,11 +104,9 @@ struct ddebug_class_map {
 		.mod_name = KBUILD_MODNAME,				\
 		.base = _base,						\
 		.map_type = _maptype,					\
-		.length = NUM_TYPE_ARGS(char*, __VA_ARGS__),		\
+		.length = ARRAY_SIZE(_var##_classnames),		\
 		.class_names = _var##_classnames,			\
 	}
-#define NUM_TYPE_ARGS(eltype, ...)				\
-        (sizeof((eltype[]){__VA_ARGS__}) / sizeof(eltype))
 
 /* encapsulate linker provided built-in (or module) dyndbg data */
 struct _ddebug_info {
-- 
2.41.0

[PATCH v5 08/23] dyndbg: reduce verbose/debug clutter

[Jim Cromie]

currently, for verbose=3, these are logged (blank lines for clarity):

 dyndbg: query 0: "class DRM_UT_CORE +p" mod:*
 dyndbg: split into words: "class" "DRM_UT_CORE" "+p"

 dyndbg: op='+'
 dyndbg: flags=0x1
 dyndbg: *flagsp=0x1 *maskp=0xffffffff

 dyndbg: parsed: func="" file="" module="" format="" lineno=0-0 class=...
 dyndbg: no matches for query
 dyndbg: no-match: func="" file="" module="" format="" lineno=0-0 class=...
 dyndbg: processed 1 queries, with 0 matches, 0 errs

That is excessive, so this patch:
 - shrinks 3 lines of 2nd stanza to single line
 - drops 1st 2 lines of 3rd stanza
   3rd is like 1st, with result, not procedure.
   2nd is just status, retold in 4th, with more info.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 550d380f7690..4200c72fed09 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -265,9 +265,6 @@ static int ddebug_change(const struct ddebug_query *query,
 	}
 	mutex_unlock(&ddebug_lock);
 
-	if (!nfound && verbose)
-		pr_info("no matches for query\n");
-
 	return nfound;
 }
 
@@ -496,7 +493,6 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
 		pr_err("bad flag-op %c, at start of %s\n", *str, str);
 		return -EINVAL;
 	}
-	v3pr_info("op='%c'\n", op);
 
 	for (; *str ; ++str) {
 		for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
@@ -510,7 +506,6 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
 			return -EINVAL;
 		}
 	}
-	v3pr_info("flags=0x%x\n", modifiers->flags);
 
 	/* calculate final flags, mask based upon op */
 	switch (op) {
@@ -526,7 +521,7 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
 		modifiers->flags = 0;
 		break;
 	}
-	v3pr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
+	v3pr_info("op='%c' flags=0x%x maskp=0x%x\n", op, modifiers->flags, modifiers->mask);
 
 	return 0;
 }
@@ -536,7 +531,7 @@ static int ddebug_exec_query(char *query_string, const char *modname)
 	struct flag_settings modifiers = {};
 	struct ddebug_query query = {};
 #define MAXWORDS 9
-	int nwords, nfound;
+	int nwords;
 	char *words[MAXWORDS];
 
 	nwords = ddebug_tokenize(query_string, words, MAXWORDS);
@@ -554,10 +549,7 @@ static int ddebug_exec_query(char *query_string, const char *modname)
 		return -EINVAL;
 	}
 	/* actually go and implement the change */
-	nfound = ddebug_change(&query, &modifiers);
-	vpr_info_dq(&query, nfound ? "applied" : "no-match");
-
-	return nfound;
+	return ddebug_change(&query, &modifiers);
 }
 
 /* handle multiple queries in query string, continue on error, return
-- 
2.41.0

[PATCH v5 09/23] dyndbg: silence debugs with no-change updates

[Jim Cromie]

check for actual changes before announcing them, declutter logs.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 4200c72fed09..7430add36423 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -590,7 +590,7 @@ static int ddebug_exec_queries(char *query, const char *modname)
 	return nfound;
 }
 
-/* apply a new bitmap to the sys-knob's current bit-state */
+/* apply a new class-param setting */
 static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 				     unsigned long *new_bits, unsigned long *old_bits,
 				     const char *query_modname)
@@ -601,8 +601,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 	int matches = 0;
 	int bi, ct;
 
-	v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits, *old_bits,
-		  query_modname ?: "");
+	if (*new_bits != *old_bits)
+		v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+			  *old_bits, query_modname ?: "'*'");
 
 	for (bi = 0; bi < map->length; bi++) {
 		if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
@@ -617,8 +618,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 		v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
 			  ct, map->class_names[bi], *new_bits);
 	}
-	v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits, *old_bits,
-		  query_modname ?: "");
+	if (*new_bits != *old_bits)
+		v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+			  *old_bits, query_modname ?: "'*'");
 
 	return matches;
 }
-- 
2.41.0

[PATCH v5 10/23] dyndbg: tighten ddebug_class_name() 1st arg type

[Jim Cromie]

Change function's 1st arg-type, and deref in the caller.
The fn doesn't need any other fields in the struct.

no functional change.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 7430add36423..5139c8d45d12 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -1113,12 +1113,12 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
 #define class_in_range(class_id, map)					\
 	(class_id >= map->base && class_id < map->base + map->length)
 
-static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp)
+static const char *ddebug_class_name(struct ddebug_table *dt, struct _ddebug *dp)
 {
-	struct ddebug_class_map *map = iter->table->classes;
-	int i, nc = iter->table->num_classes;
+	struct ddebug_class_map *map = dt->classes;
+	int i;
 
-	for (i = 0; i < nc; i++, map++)
+	for (i = 0; i < dt->num_classes; i++, map++)
 		if (class_in_range(dp->class_id, map))
 			return map->class_names[dp->class_id - map->base];
 
@@ -1152,7 +1152,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 	seq_puts(m, "\"");
 
 	if (dp->class_id != _DPRINTK_CLASS_DFLT) {
-		class = ddebug_class_name(iter, dp);
+		class = ddebug_class_name(iter->table, dp);
 		if (class)
 			seq_printf(m, " class:%s", class);
 		else
-- 
2.41.0

[PATCH v5 11/23] dyndbg: tighten fn-sig of ddebug_apply_class_bitmap

[Jim Cromie]

old_bits arg is currently a pointer to the input bits, but this could
allow inadvertent changes to the input by the fn.  Disallow this.
And constify new_bits while here.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 5139c8d45d12..1bc25dc2cb51 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -592,7 +592,8 @@ static int ddebug_exec_queries(char *query, const char *modname)
 
 /* apply a new class-param setting */
 static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
-				     unsigned long *new_bits, unsigned long *old_bits,
+				     const unsigned long *new_bits,
+				     const unsigned long old_bits,
 				     const char *query_modname)
 {
 #define QUERY_SIZE 128
@@ -601,12 +602,12 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 	int matches = 0;
 	int bi, ct;
 
-	if (*new_bits != *old_bits)
+	if (*new_bits != old_bits)
 		v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
-			  *old_bits, query_modname ?: "'*'");
+			  old_bits, query_modname ?: "'*'");
 
 	for (bi = 0; bi < map->length; bi++) {
-		if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
+		if (test_bit(bi, new_bits) == test_bit(bi, &old_bits))
 			continue;
 
 		snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
@@ -618,9 +619,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 		v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
 			  ct, map->class_names[bi], *new_bits);
 	}
-	if (*new_bits != *old_bits)
+	if (*new_bits != old_bits)
 		v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
-			  *old_bits, query_modname ?: "'*'");
+			  old_bits, query_modname ?: "'*'");
 
 	return matches;
 }
@@ -677,7 +678,7 @@ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_pa
 				continue;
 			}
 			curr_bits ^= BIT(cls_id);
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits, NULL);
+			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, *dcp->bits, NULL);
 			*dcp->bits = curr_bits;
 			v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
 				  map->class_names[cls_id]);
@@ -687,7 +688,7 @@ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_pa
 			old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 			curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));
 
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits, NULL);
+			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, old_bits, NULL);
 			*dcp->lvl = (cls_id + (wanted ? 1 : 0));
 			v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
 				  map->class_names[cls_id], old_bits, curr_bits);
@@ -741,7 +742,7 @@ static int param_set_dyndbg_module_classes(const char *instr,
 			inrep &= CLASSMAP_BITMASK(map->length);
 		}
 		v2pr_info("bits:0x%lx > %s.%s\n", inrep, modnm ?: "*", KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits, modnm);
+		totct += ddebug_apply_class_bitmap(dcp, &inrep, *dcp->bits, modnm);
 		*dcp->bits = inrep;
 		break;
 	case DD_CLASS_TYPE_LEVEL_NUM:
@@ -754,7 +755,7 @@ static int param_set_dyndbg_module_classes(const char *instr,
 		old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 		new_bits = CLASSMAP_BITMASK(inrep);
 		v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits, modnm);
+		totct += ddebug_apply_class_bitmap(dcp, &new_bits, old_bits, modnm);
 		*dcp->lvl = inrep;
 		break;
 	default:
-- 
2.41.0

[PATCH v5 12/23] dyndbg-API: remove DD_CLASS_TYPE_(DISJOINT|LEVEL)_NAMES and code

[Jim Cromie]

Remove the NAMED class types; these 2 classmap types accept class
names at the PARAM interface, for example:

  echo +DRM_UT_CORE,-DRM_UT_KMS > /sys/module/drm/parameters/debug_names

The code works, but its only used by test-dynamic-debug, and wasn't
asked for by anyone else, so simplify things for now.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h |  19 ++-----
 lib/dynamic_debug.c           | 103 +++-------------------------------
 lib/test_dynamic_debug.c      |  12 ----
 3 files changed, 12 insertions(+), 122 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 719c5b6ad0f9..b927dfacc429 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -59,24 +59,13 @@ struct _ddebug {
 enum class_map_type {
 	DD_CLASS_TYPE_DISJOINT_BITS,
 	/**
-	 * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, one per bit.
-	 * expecting hex input. Built for drm.debug, basis for other types.
+	 * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, mapped to bits[0..N].
+	 * Expects hex input. Built for drm.debug, basis for other types.
 	 */
 	DD_CLASS_TYPE_LEVEL_NUM,
 	/**
-	 * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0-N.
-	 * N turns on just bits N-1 .. 0, so N=0 turns all bits off.
-	 */
-	DD_CLASS_TYPE_DISJOINT_NAMES,
-	/**
-	 * DD_CLASS_TYPE_DISJOINT_NAMES: input is a CSV of [+-]CLASS_NAMES,
-	 * classes are independent, like _DISJOINT_BITS.
-	 */
-	DD_CLASS_TYPE_LEVEL_NAMES,
-	/**
-	 * DD_CLASS_TYPE_LEVEL_NAMES: input is a CSV of [+-]CLASS_NAMES,
-	 * intended for names like: INFO,DEBUG,TRACE, with a module prefix
-	 * avoid EMERG,ALERT,CRIT,ERR,WARNING: they're not debug
+	 * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0..N.
+	 * Input N turns on bits 0..N-1
 	 */
 };
 
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 1bc25dc2cb51..9f13320f5022 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -631,77 +631,6 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 
 #define CLASSMAP_BITMASK(width) ((1UL << (width)) - 1)
 
-/* accept comma-separated-list of [+-] classnames */
-static int param_set_dyndbg_classnames(const char *instr, const struct kernel_param *kp)
-{
-	const struct ddebug_class_param *dcp = kp->arg;
-	const struct ddebug_class_map *map = dcp->map;
-	unsigned long curr_bits, old_bits;
-	char *cl_str, *p, *tmp;
-	int cls_id, totct = 0;
-	bool wanted;
-
-	cl_str = tmp = kstrdup(instr, GFP_KERNEL);
-	p = strchr(cl_str, '\n');
-	if (p)
-		*p = '\0';
-
-	/* start with previously set state-bits, then modify */
-	curr_bits = old_bits = *dcp->bits;
-	vpr_info("\"%s\" > %s:0x%lx\n", cl_str, KP_NAME(kp), curr_bits);
-
-	for (; cl_str; cl_str = p) {
-		p = strchr(cl_str, ',');
-		if (p)
-			*p++ = '\0';
-
-		if (*cl_str == '-') {
-			wanted = false;
-			cl_str++;
-		} else {
-			wanted = true;
-			if (*cl_str == '+')
-				cl_str++;
-		}
-		cls_id = match_string(map->class_names, map->length, cl_str);
-		if (cls_id < 0) {
-			pr_err("%s unknown to %s\n", cl_str, KP_NAME(kp));
-			continue;
-		}
-
-		/* have one or more valid class_ids of one *_NAMES type */
-		switch (map->map_type) {
-		case DD_CLASS_TYPE_DISJOINT_NAMES:
-			/* the +/- pertains to a single bit */
-			if (test_bit(cls_id, &curr_bits) == wanted) {
-				v3pr_info("no change on %s\n", cl_str);
-				continue;
-			}
-			curr_bits ^= BIT(cls_id);
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, *dcp->bits, NULL);
-			*dcp->bits = curr_bits;
-			v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
-				  map->class_names[cls_id]);
-			break;
-		case DD_CLASS_TYPE_LEVEL_NAMES:
-			/* cls_id = N in 0..max. wanted +/- determines N or N-1 */
-			old_bits = CLASSMAP_BITMASK(*dcp->lvl);
-			curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));
-
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, old_bits, NULL);
-			*dcp->lvl = (cls_id + (wanted ? 1 : 0));
-			v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
-				  map->class_names[cls_id], old_bits, curr_bits);
-			break;
-		default:
-			pr_err("illegal map-type value %d\n", map->map_type);
-		}
-	}
-	kfree(tmp);
-	vpr_info("total matches: %d\n", totct);
-	return 0;
-}
-
 static int param_set_dyndbg_module_classes(const char *instr,
 					   const struct kernel_param *kp,
 					   const char *modnm)
@@ -710,29 +639,17 @@ static int param_set_dyndbg_module_classes(const char *instr,
 	const struct ddebug_class_map *map = dcp->map;
 	unsigned long inrep, new_bits, old_bits;
 	int rc, totct = 0;
-
-	switch (map->map_type) {
-
-	case DD_CLASS_TYPE_DISJOINT_NAMES:
-	case DD_CLASS_TYPE_LEVEL_NAMES:
-		/* handle [+-]classnames list separately, we are done here */
-		return param_set_dyndbg_classnames(instr, kp);
-
-	case DD_CLASS_TYPE_DISJOINT_BITS:
-	case DD_CLASS_TYPE_LEVEL_NUM:
-		/* numeric input, accept and fall-thru */
-		rc = kstrtoul(instr, 0, &inrep);
-		if (rc) {
-			pr_err("expecting numeric input: %s > %s\n", instr, KP_NAME(kp));
-			return -EINVAL;
-		}
-		break;
-	default:
-		pr_err("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
+	char *nl;
+
+	rc = kstrtoul(instr, 0, &inrep);
+	if (rc) {
+		nl = strchr(instr, '\n');
+		if (nl)
+			*nl = '\0';
+		pr_err("expecting numeric input, not: %s > %s\n", instr, KP_NAME(kp));
 		return -EINVAL;
 	}
 
-	/* only _BITS,_NUM (numeric) map-types get here */
 	switch (map->map_type) {
 	case DD_CLASS_TYPE_DISJOINT_BITS:
 		/* expect bits. mask and warn if too many */
@@ -797,12 +714,8 @@ int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
 	const struct ddebug_class_map *map = dcp->map;
 
 	switch (map->map_type) {
-
-	case DD_CLASS_TYPE_DISJOINT_NAMES:
 	case DD_CLASS_TYPE_DISJOINT_BITS:
 		return scnprintf(buffer, PAGE_SIZE, "0x%lx\n", *dcp->bits);
-
-	case DD_CLASS_TYPE_LEVEL_NAMES:
 	case DD_CLASS_TYPE_LEVEL_NUM:
 		return scnprintf(buffer, PAGE_SIZE, "%ld\n", *dcp->lvl);
 	default:
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index a01f0193a419..229eaadee838 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -102,10 +102,6 @@ static void do_cats(void)
 {
 	pr_debug("doing categories\n");
 
-	prdbg(LOW);
-	prdbg(MID);
-	prdbg(HI);
-
 	prdbg(D2_CORE);
 	prdbg(D2_DRIVER);
 	prdbg(D2_KMS);
@@ -129,14 +125,6 @@ static void do_levels(void)
 	prdbg(V5);
 	prdbg(V6);
 	prdbg(V7);
-
-	prdbg(L1);
-	prdbg(L2);
-	prdbg(L3);
-	prdbg(L4);
-	prdbg(L5);
-	prdbg(L6);
-	prdbg(L7);
 }
 
 static void do_prints(void)
-- 
2.41.0

[PATCH v5 13/22] checkpatch: file-scoped extern special case for linker-symbol

[Jim Cromie]

"externs should be avoided in .c files" needs an exception for linker
symbols, like those that mark the start, stop of many kernel sections.

Since code already checks REALNAME to avoid linker-scripts entirely,
add a new else-if block to look at them instead.  As a simple
heuristic, treat all words (in the patch-line) as possible symbols,
and save them to screen the WARN quoted above.  For my test case, this
included BOUNDED_BY (a macro), which is extra, but not troublesome.

Where the WARN is issued, precede it with an else-if block to catch
one common extern-in-c use case: "extern struct foo bar[]".  Here we
can at least issue a softer warning, after checking for a match with a
maybe-linker-symbol parsed earlier from the patch.  Though heuristic,
it worked for my test-case, allowing both (start|stop)$symbol's,
matched by $symbol, it wasn't thrown by noise (BOUNDED_BY) in the
maybe-linker-symbols.

NB: git diff ordering dependence on vmlinux.lds.h before c files ?

Cc: apw@canonical.com
Cc: joe@perches.com
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 scripts/checkpatch.pl | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index b30114d637c4..f6b6b2a50dfe 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -74,6 +74,8 @@ my $git_command ='export LANGUAGE=en_US.UTF-8; git';
 my $tabsize = 8;
 my ${CONFIG_} = "CONFIG_";
 
+my %maybe_linker_symbol; # for externs in c exceptions, when seen in *vmlinux.lds.h
+
 sub help {
 	my ($exitcode) = @_;
 
@@ -6051,6 +6053,9 @@ sub process {
 
 # check for line continuations outside of #defines, preprocessor #, and asm
 
+		} elsif ($realfile =~ m@/vmlinux.lds.h$@) {
+		    $line =~ s/(\w+)/$maybe_linker_symbol{$1}++/ge;
+		    #print "REAL: $realfile\nln: $line\nkeys:", sort keys %maybe_linker_symbol;
 		} else {
 			if ($prevline !~ /^..*\\$/ &&
 			    $line !~ /^\+\s*\#.*\\$/ &&		# preprocessor
@@ -7107,6 +7112,21 @@ sub process {
 				     "arguments for function declarations should follow identifier\n" . $herecurr);
 			}
 
+		} elsif ($realfile =~ /\.c$/ && defined $stat &&
+		    $stat =~ /^\+extern struct\s+(\w+)\s+(\w+)\[\];/)
+		{
+			my ($st_type, $st_name) = ($1, $2);
+
+			for my $s (keys %maybe_linker_symbol) {
+			    #print "Linker symbol? $st_name : $s\n";
+			    goto LIKELY_LINKER_SYMBOL
+				if $st_name =~ /$s/;
+			}
+			WARN("AVOID_EXTERNS",
+			     "found a file-scoped extern type:$st_type name:$st_name in .c file\n"
+			     . "is this a linker symbol ?\n" . $herecurr);
+		  LIKELY_LINKER_SYMBOL:
+
 		} elsif ($realfile =~ /\.c$/ && defined $stat &&
 		    $stat =~ /^.\s*extern\s+/)
 		{
-- 
2.41.0

[PATCH v5 13/23] checkpatch: special case for file-scoped extern linker-symbol

[Jim Cromie]

"externs should be avoided in .c files" needs an exception for linker
symbols, like those that mark the start, stop of many kernel sections.

Since code already checks REALNAME to avoid linker-scripts entirely,
add a new else-if block to look at them instead.  As a simple
heuristic, treat all words (in the patch-line) as possible symbols,
and save them to screen the WARN quoted above.

For my test case, this included BOUNDED_BY (a macro), which is extra,
but not troublesome - any extra words collected would have to also be
symbols the script would otherwise complain about.

Where the WARN is issued, precede it with an else-if block to catch
one common extern-in-c use case: "extern struct foo bar[]".  Here we
can at least issue a softer warning, after checking for a match with a
maybe-linker-symbol parsed earlier from the patch.  Though heuristic,
it worked for my test-case, allowing both (start|stop)$symbol's,
matched by $symbol, it wasn't thrown by noise (BOUNDED_BY) in the
maybe-linker-symbols.

NB: git diff ordering dependence on vmlinux.lds.h before c files ?

Cc: apw@canonical.com
Cc: joe@perches.com
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 scripts/checkpatch.pl | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index b30114d637c4..f6b6b2a50dfe 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -74,6 +74,8 @@ my $git_command ='export LANGUAGE=en_US.UTF-8; git';
 my $tabsize = 8;
 my ${CONFIG_} = "CONFIG_";
 
+my %maybe_linker_symbol; # for externs in c exceptions, when seen in *vmlinux.lds.h
+
 sub help {
 	my ($exitcode) = @_;
 
@@ -6051,6 +6053,9 @@ sub process {
 
 # check for line continuations outside of #defines, preprocessor #, and asm
 
+		} elsif ($realfile =~ m@/vmlinux.lds.h$@) {
+		    $line =~ s/(\w+)/$maybe_linker_symbol{$1}++/ge;
+		    #print "REAL: $realfile\nln: $line\nkeys:", sort keys %maybe_linker_symbol;
 		} else {
 			if ($prevline !~ /^..*\\$/ &&
 			    $line !~ /^\+\s*\#.*\\$/ &&		# preprocessor
@@ -7107,6 +7112,21 @@ sub process {
 				     "arguments for function declarations should follow identifier\n" . $herecurr);
 			}
 
+		} elsif ($realfile =~ /\.c$/ && defined $stat &&
+		    $stat =~ /^\+extern struct\s+(\w+)\s+(\w+)\[\];/)
+		{
+			my ($st_type, $st_name) = ($1, $2);
+
+			for my $s (keys %maybe_linker_symbol) {
+			    #print "Linker symbol? $st_name : $s\n";
+			    goto LIKELY_LINKER_SYMBOL
+				if $st_name =~ /$s/;
+			}
+			WARN("AVOID_EXTERNS",
+			     "found a file-scoped extern type:$st_type name:$st_name in .c file\n"
+			     . "is this a linker symbol ?\n" . $herecurr);
+		  LIKELY_LINKER_SYMBOL:
+
 		} elsif ($realfile =~ /\.c$/ && defined $stat &&
 		    $stat =~ /^.\s*extern\s+/)
 		{
-- 
2.41.0

[PATCH v5 14/23] dyndbg-API: fix CONFIG_DRM_USE_DYNAMIC_DEBUG regression

[Jim Cromie]

DECLARE_DYNDBG_CLASSMAP() has a design error; it fails a basic K&R
rule: "define once, refer many times".

When DRM_USE_DYNAMIC_DEBUG=y, DECLARE_DYNDBG_CLASSMAP() is used across
DRM core & drivers; they all repeat the same classmap-defn args, which
must match for the modules to respond together when DRM.debug
categories are enabled.

Worse, it causes the CONFIG_DRM_USE_DYNAMIC_DEBUG=Y regression; 1st
drm.ko loads, and dyndbg initializes its DRM.debug callsites, then a
drm-driver loads, but too late - it missed the DRM.debug enablement.

So replace it with 2 macros:
  DYNDBG_CLASSMAP_DEFINE - invoked once from core - drm.ko
  DYNDBG_CLASSMAP_USE    - from all drm drivers and helpers.

DYNDBG_CLASSMAP_DEFINE: based on DECLARE_DYNDBG_CLASSMAP, but now it
drops the static on the constructed classmap variable, and exports it
instead.

DYNDBG_CLASSMAP_USE: then refers to the exported var by name:
* used from drivers, helper-mods
* lets us drop the repetitive "classname" args
* fixes 2nd-defn problem
* creates a ddebug_class_user record in new __dyndbg_class_users section
  this allows ddebug_add_module(etal) to handle them per-module.

The distinction, and the usage record, allows dyndbg to initialize the
driver's DRM.debug callsites separately after it is modprobed.

Since DRM now needs updates to use the new macros, it also gets 2
wrappers: DRM_CLASSMAP_DEFINE, DRM_CLASSMAP_USE which declutter the
users by hiding the ifdef CONFIG_DRM_USE_DYNAMIC_DEBUG.

To review, dyndbg's existing __dyndbg_classes[] section does:

. catalogs the classmaps defined by the module (or builtin modules)
. authorizes dyndbg to >control those class'd prdbgs for the module.
. DYNDBG_CLASSMAP_DEFINE(and old one) creates classmaps in this section.

This patch adds __dyndbg_class_users[] section:

. catalogs uses/references to the classmap definitions.
. authorizes dyndbg to >control those class'd prdbgs in ref'g module.
. DYNDBG_CLASSMAP_USE() creates classmap-user records in this section.

Now ddebug_add_module(etal) can handle classmap-uses like (and after)
classmaps; when a dependent module is loaded, its parent's kernel
params are scanned to find the param wired to dyndbg-param-ops, whose
classmap matches the one ref'd by the client.

To support this, a few data/header changes:

. new struct ddebug_class_user
  contains: user-module-name, &classmap-defn
  it records drm-driver's use of a classmap in the section, allowing lookup

struct ddebug_info gets 2 new fields to encapsulate the new section:
  class_users, num_class_users.
  set by dynamic_debug_init() for builtins.
  or by kernel/module/main:load_info() for loadable modules.

vmlinux.lds.h: new BOUNDED_SECTION for __dyndbg_class_users

dynamic_debug.c has 2 changes in ddebug_add_module(), ddebug_change():

ddebug_add_module() previously called ddebug_attach_module_classes()
to handle classmap DEFINEd by a module, now it also calls
ddebug_attach_user_module_classes() to handle USEd classmaps.

ddebug_attach_user_module_classes() scans the module's class_users
section, follows the refs to the parent's classmap, and calls
ddebug_apply_params() on each.

ddebug_apply_params(new fn):

It scans module's/builtin kernel-params, calls ddebug_match_attach_kparam
for each to find the params/sysfs-nodes which may be wired to a classmap.

ddebug_match_apply_kparam(new fn):

1st, it tests the kernel-param.ops is dyndbg's; this guarantees that
the attached arg is a struct ddebug_class_param, which has a ref to
the param's state, and to the classmap defining the param's handling.

2nd, it requires that the classmap ref'd by the kparam is the one
we're called for; modules can use many separate classmaps (as
test_dynamic_debug does).

Then apply the "parent" kparam's setting to the dependent module,
using ddebug_apply_class_bitmap().

ddebug_change(and callees) also gets adjustments:

ddebug_find_valid_class(): This does a search over the module's
classmaps, looking for the class FOO echo'd to >control.  So now it
searches over __dyndbg_class_users[] after __dyndbg_classes[].

ddebug_class_name(): return class-names for defined AND used classes.

test_dynamic_debug.c, test_dynamic_debug_submod.c:

This (already) demonstrates the 2 types of classmaps & sysfs-params,
following the 4-part recipe:

1. define an enum for the classmap: DRM.debug has DRM_UT_{CORE,KMS,...}
   multiple classes must share 0-62 classid space.
2. DYNDBG_CLASSMAP_DEFINE(.. DRM_UT_{CORE,KMS,...})
3. DYNDBG_CLASSMAP_PARAM* (classmap)
4. DYNDBG_CLASSMAP_USE()
   by _submod only, skipping 2,3

Move all the enum declarations together, to better explain how they
share the 0..62 class-id space available to a module (non-overlapping
subranges).

reorg macros 2,3 by name.  This gives a tabular format, making it easy
to see the pattern of repetition, and the points of change.

And extend the test to replicate the 2-module (parent & dependent)
scenario which caused the CONFIG_DRM_USE_DYNAMIC_DEBUG=y regression
seen in drm & drivers.

The _submod.c is a 2-line file: #define _SUBMOD, #include parent.

This gives identical complements of prdbgs in parent & _submod, and
thus identical print behavior when all of: >control, >params, and
parent->_submod propagation are working correctly.

It also puts all the parent/_submod declarations together in the same
source, with the new ifdef _SUBMOD block invoking DYNDBG_CLASSMAP_USE
for the 2 test-interfaces.  I think this is clearer.

DEBUG details:

``#define DEBUG`` in src enables all pr_debugs after it, including any
class'd pr_debugs; its not necessarily all-or-nothing, unless its a
one-file-module with DEBUG at the top.

If a CLASSMAP_PARAM is defined on a classmap, its readback value
cannot describe the set of enablements.  The param is basically
write-only; it cannot know if `echo $cmd >control` was done since.

To know the exact pr-debug state with certainty, toggle to both:

   echo 0x3ff > /sys/module/drm/parameters/debug
   echo 0     > /sys/module/drm/parameters/debug

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Fixes: aad0214f3026 ("dyndbg: add DECLARE_DYNDBG_CLASSMAP macro")
Fixes: f158936b60a7 ("drm: POC drm on dyndbg - use in core, 2 helpers, 3 drivers.")
Ref: commit bb2ff6c27bc9 ("drm: Disable dynamic debug as broken")

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 MAINTAINERS                             |   2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c |  12 +-
 drivers/gpu/drm/display/drm_dp_helper.c |  12 +-
 drivers/gpu/drm/drm_crtc_helper.c       |  12 +-
 drivers/gpu/drm/drm_print.c             |  25 ++--
 drivers/gpu/drm/i915/i915_params.c      |  12 +-
 drivers/gpu/drm/nouveau/nouveau_drm.c   |  12 +-
 include/asm-generic/vmlinux.lds.h       |   1 +
 include/drm/drm_print.h                 |  10 +-
 include/linux/dynamic_debug.h           |  54 +++++--
 kernel/module/main.c                    |   3 +
 lib/Makefile                            |   2 +-
 lib/dynamic_debug.c                     | 178 ++++++++++++++++++++----
 lib/test_dynamic_debug.c                | 127 +++++++++++------
 lib/test_dynamic_debug_submod.c         |  10 ++
 15 files changed, 321 insertions(+), 151 deletions(-)
 create mode 100644 lib/test_dynamic_debug_submod.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 35e19594640d..22271637de83 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7257,7 +7257,7 @@ M:	Jim Cromie <jim.cromie@gmail.com>
 S:	Maintained
 F:	include/linux/dynamic_debug.h
 F:	lib/dynamic_debug.c
-F:	lib/test_dynamic_debug.c
+F:	lib/test_dynamic_debug*.c
 
 DYNAMIC INTERRUPT MODERATION
 M:	Tal Gilboa <talgi@nvidia.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index 393b6fb7a71d..e62fac197aca 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -194,17 +194,7 @@ int amdgpu_sg_display = -1; /* auto */
 
 static void amdgpu_drv_delayed_reset_work_handler(struct work_struct *work);
 
-DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
-			"DRM_UT_CORE",
-			"DRM_UT_DRIVER",
-			"DRM_UT_KMS",
-			"DRM_UT_PRIME",
-			"DRM_UT_ATOMIC",
-			"DRM_UT_VBL",
-			"DRM_UT_STATE",
-			"DRM_UT_LEASE",
-			"DRM_UT_DP",
-			"DRM_UT_DRMRES");
+DRM_CLASSMAP_USE(drm_debug_classes);
 
 struct amdgpu_mgpu_info mgpu_info = {
 	.mutex = __MUTEX_INITIALIZER(mgpu_info.mutex),
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
index 16565a0a5da6..94a71d568951 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -41,17 +41,7 @@
 
 #include "drm_dp_helper_internal.h"
 
-DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
-			"DRM_UT_CORE",
-			"DRM_UT_DRIVER",
-			"DRM_UT_KMS",
-			"DRM_UT_PRIME",
-			"DRM_UT_ATOMIC",
-			"DRM_UT_VBL",
-			"DRM_UT_STATE",
-			"DRM_UT_LEASE",
-			"DRM_UT_DP",
-			"DRM_UT_DRMRES");
+DRM_CLASSMAP_USE(drm_debug_classes);
 
 struct dp_aux_backlight {
 	struct backlight_device *base;
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index a209659a996c..fef4662d5f1f 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -50,17 +50,7 @@
 
 #include "drm_crtc_helper_internal.h"
 
-DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
-			"DRM_UT_CORE",
-			"DRM_UT_DRIVER",
-			"DRM_UT_KMS",
-			"DRM_UT_PRIME",
-			"DRM_UT_ATOMIC",
-			"DRM_UT_VBL",
-			"DRM_UT_STATE",
-			"DRM_UT_LEASE",
-			"DRM_UT_DP",
-			"DRM_UT_DRMRES");
+DRM_CLASSMAP_USE(drm_debug_classes);
 
 /**
  * DOC: overview
diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
index 5b93c11895bb..dabcfa0dd279 100644
--- a/drivers/gpu/drm/drm_print.c
+++ b/drivers/gpu/drm/drm_print.c
@@ -55,18 +55,19 @@ MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug cat
 #if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
 module_param_named(debug, __drm_debug, ulong, 0600);
 #else
-/* classnames must match vals of enum drm_debug_category */
-DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
-			"DRM_UT_CORE",
-			"DRM_UT_DRIVER",
-			"DRM_UT_KMS",
-			"DRM_UT_PRIME",
-			"DRM_UT_ATOMIC",
-			"DRM_UT_VBL",
-			"DRM_UT_STATE",
-			"DRM_UT_LEASE",
-			"DRM_UT_DP",
-			"DRM_UT_DRMRES");
+/* classnames must match value-symbols of enum drm_debug_category */
+DRM_CLASSMAP_DEFINE(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS,
+		    DRM_UT_CORE,
+		    "DRM_UT_CORE",
+		    "DRM_UT_DRIVER",
+		    "DRM_UT_KMS",
+		    "DRM_UT_PRIME",
+		    "DRM_UT_ATOMIC",
+		    "DRM_UT_VBL",
+		    "DRM_UT_STATE",
+		    "DRM_UT_LEASE",
+		    "DRM_UT_DP",
+		    "DRM_UT_DRMRES");
 
 static struct ddebug_class_param drm_debug_bitmap = {
 	.bits = &__drm_debug,
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 0a171b57fd8f..d870e15da21c 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -29,17 +29,7 @@
 #include "i915_params.h"
 #include "i915_drv.h"
 
-DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
-			"DRM_UT_CORE",
-			"DRM_UT_DRIVER",
-			"DRM_UT_KMS",
-			"DRM_UT_PRIME",
-			"DRM_UT_ATOMIC",
-			"DRM_UT_VBL",
-			"DRM_UT_STATE",
-			"DRM_UT_LEASE",
-			"DRM_UT_DP",
-			"DRM_UT_DRMRES");
+DRM_CLASSMAP_USE(drm_debug_classes);
 
 #define i915_param_named(name, T, perm, desc) \
 	module_param_named(name, i915_modparams.name, T, perm); \
diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
index 7aac9384600e..4c7087fb55ad 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -69,17 +69,7 @@
 #include "nouveau_svm.h"
 #include "nouveau_dmem.h"
 
-DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
-			"DRM_UT_CORE",
-			"DRM_UT_DRIVER",
-			"DRM_UT_KMS",
-			"DRM_UT_PRIME",
-			"DRM_UT_ATOMIC",
-			"DRM_UT_VBL",
-			"DRM_UT_STATE",
-			"DRM_UT_LEASE",
-			"DRM_UT_DP",
-			"DRM_UT_DRMRES");
+DRM_CLASSMAP_USE(drm_debug_classes);
 
 MODULE_PARM_DESC(config, "option string to pass to driver core");
 static char *nouveau_config;
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index da9e5629ea43..64e4518591be 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -373,6 +373,7 @@
 	/* implement dynamic printk debug */				\
 	. = ALIGN(8);							\
 	BOUNDED_SECTION_BY(__dyndbg_classes, ___dyndbg_classes)		\
+	BOUNDED_SECTION_BY(__dyndbg_class_users, ___dyndbg_class_users)	\
 	BOUNDED_SECTION_BY(__dyndbg, ___dyndbg)				\
 	LIKELY_PROFILE()		       				\
 	BRANCH_PROFILE()						\
diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index a93a387f8a1a..706afc97c79c 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -276,7 +276,7 @@ static inline struct drm_printer drm_err_printer(const char *prefix)
  *
  */
 enum drm_debug_category {
-	/* These names must match those in DYNAMIC_DEBUG_CLASSBITS */
+	/* Keep DRM_CLASSMAP_DEFINE args in sync with any changes here */
 	/**
 	 * @DRM_UT_CORE: Used in the generic drm code: drm_ioctl.c, drm_mm.c,
 	 * drm_memory.c, ...
@@ -321,6 +321,14 @@ enum drm_debug_category {
 	DRM_UT_DRMRES
 };
 
+#ifdef CONFIG_DRM_USE_DYNAMIC_DEBUG
+#define DRM_CLASSMAP_DEFINE(...) DYNDBG_CLASSMAP_DEFINE(__VA_ARGS__)
+#define DRM_CLASSMAP_USE(name)   DYNDBG_CLASSMAP_USE(name)
+#else
+#define DRM_CLASSMAP_DEFINE(...)
+#define DRM_CLASSMAP_USE(name)
+#endif
+
 static inline bool drm_debug_enabled_raw(enum drm_debug_category category)
 {
 	return unlikely(__drm_debug & BIT(category));
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index b927dfacc429..85f9b91034ca 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -56,7 +56,7 @@ struct _ddebug {
 #endif
 } __attribute__((aligned(8)));
 
-enum class_map_type {
+enum ddebug_class_map_type {
 	DD_CLASS_TYPE_DISJOINT_BITS,
 	/**
 	 * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, mapped to bits[0..N].
@@ -70,24 +70,28 @@ enum class_map_type {
 };
 
 struct ddebug_class_map {
-	struct module *mod;
-	const char *mod_name;	/* needed for builtins */
+	const struct module *mod;		/* NULL for builtins */
+	const char *mod_name;
 	const char **class_names;
 	const int length;
 	const int base;		/* index of 1st .class_id, allows split/shared space */
-	enum class_map_type map_type;
+	enum ddebug_class_map_type map_type;
 };
 
 /**
- * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
- * @_var:   a struct ddebug_class_map, passed to module_param_cb
- * @_type:  enum class_map_type, chooses bits/verbose, numeric/symbolic
- * @_base:  offset of 1st class-name. splits .class_id space
- * @classes: class-names used to control class'd prdbgs
+ * DYNDBG_CLASSMAP_DEFINE - define a set of debug-classes used by a module.
+ * @_var:   name of the classmap, exported for other modules coordinated use.
+ * @_type:  enum ddebug_class_map_type, chooses bits/verbose, numeric/names.
+ * @_base:  offset of 1st class-name, used to share 0..62 classid space
+ * @classes: vals are stringified enum-vals, like DRM_UT_*
+ *
+ * Defines and exports a struct ddebug_class_map whose @classes are
+ * used to validate a "class FOO .." >control command against each
+ * module, and to validate inputs to DD_CLASS_TYPE_*_NAMES typed params.
  */
-#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...)		\
-	static const char *_var##_classnames[] = { __VA_ARGS__ };	\
-	static struct ddebug_class_map __aligned(8) __used		\
+#define DYNDBG_CLASSMAP_DEFINE(_var, _maptype, _base, ...)		\
+	const char *_var##_classnames[] = { __VA_ARGS__ };		\
+	struct ddebug_class_map __aligned(8) __used			\
 		__section("__dyndbg_classes") _var = {			\
 		.mod = THIS_MODULE,					\
 		.mod_name = KBUILD_MODNAME,				\
@@ -95,14 +99,40 @@ struct ddebug_class_map {
 		.map_type = _maptype,					\
 		.length = ARRAY_SIZE(_var##_classnames),		\
 		.class_names = _var##_classnames,			\
+	};								\
+	EXPORT_SYMBOL(_var)
+
+struct ddebug_class_user {
+	char *user_mod_name;
+	struct ddebug_class_map *map;
+};
+
+/**
+ * DYNDBG_CLASSMAP_USE - refer to a classmap, DEFINEd elsewhere.
+ * @_var: name of the exported classmap var
+ *
+ * This registers a module's use of another module's classmap defn, so
+ * dyndbg can authorize "class DRM_CORE ..." >control commands upon
+ * this module.
+ */
+#define DYNDBG_CLASSMAP_USE(_var)					\
+	DYNDBG_CLASSMAP_USE_(_var, __UNIQUE_ID(ddebug_class_user))
+#define DYNDBG_CLASSMAP_USE_(_var, _uname)				\
+	extern struct ddebug_class_map _var;				\
+	struct ddebug_class_user __used					\
+	__section("__dyndbg_class_users") _uname = {			\
+		.user_mod_name = KBUILD_MODNAME,			\
+		.map = &_var,						\
 	}
 
 /* encapsulate linker provided built-in (or module) dyndbg data */
 struct _ddebug_info {
 	struct _ddebug *descs;
 	struct ddebug_class_map *classes;
+	struct ddebug_class_user *class_users;
 	unsigned int num_descs;
 	unsigned int num_classes;
+	unsigned int num_class_users;
 };
 
 struct ddebug_class_param {
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 4e2cf784cf8c..79c05b545643 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2213,6 +2213,9 @@ static int find_module_sections(struct module *mod, struct load_info *info)
 	mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes",
 						sizeof(*mod->dyndbg_info.classes),
 						&mod->dyndbg_info.num_classes);
+	mod->dyndbg_info.class_users = section_objs(info, "__dyndbg_class_users",
+						    sizeof(*mod->dyndbg_info.class_users),
+						   &mod->dyndbg_info.num_class_users);
 #endif
 
 	return 0;
diff --git a/lib/Makefile b/lib/Makefile
index 876fcdeae34e..f36048371dd2 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -79,7 +79,7 @@ obj-$(CONFIG_TEST_SORT) += test_sort.o
 obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
 obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
 obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
-obj-$(CONFIG_TEST_DYNAMIC_DEBUG) += test_dynamic_debug.o
+obj-$(CONFIG_TEST_DYNAMIC_DEBUG) += test_dynamic_debug.o test_dynamic_debug_submod.o
 obj-$(CONFIG_TEST_PRINTF) += test_printf.o
 obj-$(CONFIG_TEST_SCANF) += test_scanf.o
 obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 9f13320f5022..e10fe6ed29cc 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -43,13 +43,16 @@ extern struct _ddebug __start___dyndbg[];
 extern struct _ddebug __stop___dyndbg[];
 extern struct ddebug_class_map __start___dyndbg_classes[];
 extern struct ddebug_class_map __stop___dyndbg_classes[];
+extern struct ddebug_class_user __start___dyndbg_class_users[];
+extern struct ddebug_class_user __stop___dyndbg_class_users[];
 
 struct ddebug_table {
 	struct list_head link;
 	const char *mod_name;
 	struct _ddebug *ddebugs;
 	struct ddebug_class_map *classes;
-	unsigned int num_ddebugs, num_classes;
+	struct ddebug_class_user *class_users;
+	unsigned int num_ddebugs, num_classes, num_class_users;
 };
 
 struct ddebug_query {
@@ -147,21 +150,39 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 		  query->first_lineno, query->last_lineno, query->class_string);
 }
 
+#define vpr_dt_info(dt_p, msg_p, ...) ({				\
+	struct ddebug_table const *_dt = dt_p;				\
+	v2pr_info(msg_p " module:%s nd:%d nc:%d nu:%d\n", ##__VA_ARGS__, \
+		  _dt->mod_name, _dt->num_ddebugs, _dt->num_classes,	\
+		  _dt->num_class_users);				\
+	})
+
 #define __outvar /* filled by callee */
 static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
 							const char *class_string,
 							__outvar int *class_id)
 {
 	struct ddebug_class_map *map;
+	struct ddebug_class_user *cli;
 	int i, idx;
 
-	for (map = dt->classes, i = 0; i < dt->num_classes; i++, map++) {
+	for (i = 0, map = dt->classes; i < dt->num_classes; i++, map++) {
 		idx = match_string(map->class_names, map->length, class_string);
 		if (idx >= 0) {
 			*class_id = idx + map->base;
+			vpr_dt_info(dt, "good-class: %s.%s ", map->mod_name, class_string);
 			return map;
 		}
 	}
+	for (i = 0, cli = dt->class_users; i < dt->num_class_users; i++, cli++) {
+		idx = match_string(cli->map->class_names, cli->map->length, class_string);
+		if (idx >= 0) {
+			*class_id = idx + cli->map->base;
+			vpr_dt_info(dt, "class-ref: %s.%s ",
+				    cli->user_mod_name, class_string);
+			return cli->map;
+		}
+	}
 	*class_id = -ENOENT;
 	return NULL;
 }
@@ -554,7 +575,7 @@ static int ddebug_exec_query(char *query_string, const char *modname)
 
 /* handle multiple queries in query string, continue on error, return
    last error or number of matching callsites.  Module name is either
-   in param (for boot arg) or perhaps in query string.
+   in the modname arg (for boot args) or perhaps in query string.
 */
 static int ddebug_exec_queries(char *query, const char *modname)
 {
@@ -683,12 +704,12 @@ static int param_set_dyndbg_module_classes(const char *instr,
 }
 
 /**
- * param_set_dyndbg_classes - class FOO >control
+ * param_set_dyndbg_classes - set all classes in a classmap
  * @instr: string echo>d to sysfs, input depends on map_type
- * @kp:    kp->arg has state: bits/lvl, map, map_type
+ * @kp:    kp->arg has state: bits/lvl, classmap, map_type
  *
- * Enable/disable prdbgs by their class, as given in the arguments to
- * DECLARE_DYNDBG_CLASSMAP.  For LEVEL map-types, enforce relative
+ * For all classes in the classmap, enable/disable them per the input
+ * (depending on map_type).  For LEVEL map-types, enforce relative
  * levels by bitpos.
  *
  * Returns: 0 or <0 if error.
@@ -1030,12 +1051,17 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
 static const char *ddebug_class_name(struct ddebug_table *dt, struct _ddebug *dp)
 {
 	struct ddebug_class_map *map = dt->classes;
+	struct ddebug_class_user *cli = dt->class_users;
 	int i;
 
 	for (i = 0; i < dt->num_classes; i++, map++)
 		if (class_in_range(dp->class_id, map))
 			return map->class_names[dp->class_id - map->base];
 
+	for (i = 0; i < dt->num_class_users; i++, cli++)
+		if (class_in_range(dp->class_id, cli->map))
+			return cli->map->class_names[dp->class_id - cli->map->base];
+
 	return NULL;
 }
 
@@ -1116,31 +1142,129 @@ static const struct proc_ops proc_fops = {
 	.proc_write = ddebug_proc_write
 };
 
+static const char * const ddebug_classmap_typenames[] = {
+	"DISJOINT_BITS", "LEVEL_NUM", "DISJOINT_NAMES", "LEVEL_NAMES"
+};
+
+#define vpr_cm_info(cm_p, msg_p, ...) ({				\
+	struct ddebug_class_map const *_cm = cm_p;			\
+	v2pr_info(msg_p " module:%s base:%d len:%d type:%s\n", ##__VA_ARGS__, \
+		  _cm->mod_name, _cm->base, _cm->length,		\
+		  ddebug_classmap_typenames[_cm->map_type]);		\
+	})
+
+static void ddebug_sync_classbits(const struct ddebug_class_param *dcp, const char *modname)
+{
+	/* clamp initial bitvec, mask off hi-bits */
+	if (*dcp->bits & ~CLASSMAP_BITMASK(dcp->map->length)) {
+		*dcp->bits &= CLASSMAP_BITMASK(dcp->map->length);
+		v2pr_info("preset classbits: %lx\n", *dcp->bits);
+	}
+	/* force class'd prdbgs (in USEr module) to match (DEFINEr module) class-param */
+	ddebug_apply_class_bitmap(dcp, dcp->bits, ~0, modname);
+	ddebug_apply_class_bitmap(dcp, dcp->bits, 0, modname);
+}
+
+static void ddebug_match_apply_kparam(const struct kernel_param *kp,
+				      const struct ddebug_class_map *map,
+				      const char *modnm)
+{
+	struct ddebug_class_param *dcp;
+
+	if (kp->ops != &param_ops_dyndbg_classes)
+		return;
+
+	dcp = (struct ddebug_class_param *)kp->arg;
+
+	if (map == dcp->map) {
+		v2pr_info("found kp:%s =0x%lx", kp->name, *dcp->bits);
+		vpr_cm_info(map, "mapped to:");
+		ddebug_sync_classbits(dcp, modnm);
+	}
+}
+
+static void ddebug_apply_params(const struct ddebug_class_map *cm, const char *modnm)
+{
+	const struct kernel_param *kp;
+#if IS_ENABLED(CONFIG_MODULES)
+	int i;
+
+	if (cm->mod) {
+		vpr_cm_info(cm, "loaded class:");
+		for (i = 0, kp = cm->mod->kp; i < cm->mod->num_kp; i++, kp++)
+			ddebug_match_apply_kparam(kp, cm, modnm);
+	}
+#endif
+	if (!cm->mod) {
+		vpr_cm_info(cm, "builtin class:");
+		for (kp = __start___param; kp < __stop___param; kp++)
+			ddebug_match_apply_kparam(kp, cm, modnm);
+	}
+}
+
+/*
+ * Find this module's classmaps in a sub/whole-range of the builtin/
+ * modular classmap vector/section.  Save the start and length of the
+ * subrange at its edges.
+ */
 static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
 {
 	struct ddebug_class_map *cm;
 	int i, nc = 0;
 
-	/*
-	 * 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++) {
+	for (i = 0, cm = di->classes; i < di->num_classes; i++, cm++) {
 
 		if (!strcmp(cm->mod_name, dt->mod_name)) {
-			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);
+			vpr_cm_info(cm, "classes[%d]:", i);
+			if (!nc++)
 				dt->classes = cm;
-			}
-			nc++;
 		}
 	}
-	if (nc) {
-		dt->num_classes = nc;
+	dt->num_classes = nc;
+	if (nc)
 		vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
+
+	/* now iterate dt */
+	for (i = 0, cm = dt->classes; i < dt->num_classes; i++, cm++)
+		ddebug_apply_params(cm, cm->mod_name);
+}
+
+/*
+ * propagates class-params thru their classmaps to class-users.  this
+ * means a query against the dt/module, which means it must be on the
+ * list to be seen by ddebug_change.
+ */
+static void ddebug_attach_user_module_classes(struct ddebug_table *dt,
+					      const struct _ddebug_info *di)
+{
+	struct ddebug_class_user *cli;
+	int i, nc = 0;
+
+	/*
+	 * For builtins: scan the array, find start/length of this
+	 * module's refs, save to dt.  For loadables, this is the
+	 * whole array.
+	 */
+	for (i = 0, cli = di->class_users; i < di->num_class_users; i++, cli++) {
+
+		if (WARN_ON(!cli || !cli->map || !cli->user_mod_name))
+			continue;
+
+		if (!strcmp(cli->user_mod_name, dt->mod_name)) {
+
+			vpr_cm_info(cli->map, "class_ref[%d] %s -> %s\n", i,
+				    cli->user_mod_name, cli->map->mod_name);
+			if (!nc++)
+				dt->class_users = cli;
+		}
 	}
+	dt->num_class_users = nc;
+
+	/* now iterate dt */
+	for (i = 0, cli = dt->class_users; i < dt->num_class_users; i++, cli++)
+		ddebug_apply_params(cli->map, cli->user_mod_name);
+
+	vpr_dt_info(dt, "attach-client-module: ");
 }
 
 /*
@@ -1151,7 +1275,8 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 {
 	struct ddebug_table *dt;
 
-	v3pr_info("add-module: %s.%d sites\n", modname, di->num_descs);
+	v3pr_info("add-module: %s %d sites %d.%d\n", modname, di->num_descs,
+		  di->num_classes, di->num_class_users);
 	if (!di->num_descs) {
 		v3pr_info(" skip %s\n", modname);
 		return 0;
@@ -1174,13 +1299,16 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 
 	INIT_LIST_HEAD(&dt->link);
 
-	if (di->classes && di->num_classes)
-		ddebug_attach_module_classes(dt, di);
-
 	mutex_lock(&ddebug_lock);
 	list_add_tail(&dt->link, &ddebug_tables);
 	mutex_unlock(&ddebug_lock);
 
+	if (di->num_classes)
+		ddebug_attach_module_classes(dt, di);
+
+	if (di->num_class_users)
+		ddebug_attach_user_module_classes(dt, di);
+
 	vpr_info("%3u debug prints in module %s\n", di->num_descs, modname);
 	return 0;
 }
@@ -1330,8 +1458,10 @@ static int __init dynamic_debug_init(void)
 	struct _ddebug_info di = {
 		.descs = __start___dyndbg,
 		.classes = __start___dyndbg_classes,
+		.class_users = __start___dyndbg_class_users,
 		.num_descs = __stop___dyndbg - __start___dyndbg,
 		.num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,
+		.num_class_users = __stop___dyndbg_class_users - __start___dyndbg_class_users,
 	};
 
 #ifdef CONFIG_MODULES
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 229eaadee838..23967071b60f 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -6,11 +6,15 @@
  *      Jim Cromie	<jim.cromie@gmail.com>
  */
 
-#define pr_fmt(fmt) "test_dd: " fmt
+#if defined(TEST_DYNAMIC_DEBUG_SUBMOD)
+  #define pr_fmt(fmt) "test_dd_submod: " fmt
+#else
+  #define pr_fmt(fmt) "test_dd: " fmt
+#endif
 
 #include <linux/module.h>
 
-/* run tests by reading or writing sysfs node: do_prints */
+/* re-gen output by reading or writing sysfs node: do_prints */
 
 static void do_prints(void); /* device under test */
 static int param_set_do_prints(const char *instr, const struct kernel_param *kp)
@@ -29,24 +33,39 @@ static const struct kernel_param_ops param_ops_do_prints = {
 };
 module_param_cb(do_prints, &param_ops_do_prints, NULL, 0600);
 
-/*
- * Using the CLASSMAP api:
- * - classmaps must have corresponding enum
- * - enum symbols must match/correlate with class-name strings in the map.
- * - base must equal enum's 1st value
- * - multiple maps must set their base to share the 0-30 class_id space !!
- *   (build-bug-on tips welcome)
- * Additionally, here:
- * - tie together sysname, mapname, bitsname, flagsname
- */
-#define DD_SYS_WRAP(_model, _flags)					\
-	static unsigned long bits_##_model;				\
-	static struct ddebug_class_param _flags##_model = {		\
+#define CLASSMAP_BITMASK(width, base) (((1UL << (width)) - 1) << base)
+
+/* sysfs param wrapper, proto-API */
+#define DYNDBG_CLASSMAP_PARAM_(_model, _flags, _init)			\
+	static unsigned long bits_##_model = _init;			\
+	static struct ddebug_class_param _flags##_##_model = {		\
 		.bits = &bits_##_model,					\
 		.flags = #_flags,					\
 		.map = &map_##_model,					\
 	};								\
-	module_param_cb(_flags##_##_model, &param_ops_dyndbg_classes, &_flags##_model, 0600)
+	module_param_cb(_flags##_##_model, &param_ops_dyndbg_classes,	\
+			&_flags##_##_model, 0600)
+#ifdef DEBUG
+#define DYNDBG_CLASSMAP_PARAM(_model, _flags)  DYNDBG_CLASSMAP_PARAM_(_model, _flags, ~0)
+#else
+#define DYNDBG_CLASSMAP_PARAM(_model, _flags)  DYNDBG_CLASSMAP_PARAM_(_model, _flags, 0)
+#endif
+
+/*
+ * Demonstrate/test all 4 class-typed classmaps with a sys-param.
+ *
+ * Each is 3 part: client-enum decl, _DEFINE, _PARAM.
+ * Declare them in blocks to show patterns of use (repetitions and
+ * changes) within each.
+ *
+ * 1st, dyndbg expects a client-provided enum-type as source of
+ * category/classid truth.  DRM has DRM_UT_<CORE,DRIVER,KMS,etc>.
+ *
+ * Modules with multiple CLASSMAPS must have enums with distinct
+ * value-ranges, arranged below with explicit enum_sym = X inits.
+ *
+ * Declare all 4 enums now, for different types
+ */
 
 /* numeric input, independent bits */
 enum cat_disjoint_bits {
@@ -60,40 +79,57 @@ enum cat_disjoint_bits {
 	D2_LEASE,
 	D2_DP,
 	D2_DRMRES };
-DECLARE_DYNDBG_CLASSMAP(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS, 0,
-			"D2_CORE",
-			"D2_DRIVER",
-			"D2_KMS",
-			"D2_PRIME",
-			"D2_ATOMIC",
-			"D2_VBL",
-			"D2_STATE",
-			"D2_LEASE",
-			"D2_DP",
-			"D2_DRMRES");
-DD_SYS_WRAP(disjoint_bits, p);
-DD_SYS_WRAP(disjoint_bits, T);
-
-/* symbolic input, independent bits */
-enum cat_disjoint_names { LOW = 10, MID, HI };
-DECLARE_DYNDBG_CLASSMAP(map_disjoint_names, DD_CLASS_TYPE_DISJOINT_NAMES, 10,
-			"LOW", "MID", "HI");
-DD_SYS_WRAP(disjoint_names, p);
-DD_SYS_WRAP(disjoint_names, T);
 
 /* numeric verbosity, V2 > V1 related */
 enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 };
-DECLARE_DYNDBG_CLASSMAP(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, 14,
-		       "V0", "V1", "V2", "V3", "V4", "V5", "V6", "V7");
-DD_SYS_WRAP(level_num, p);
-DD_SYS_WRAP(level_num, T);
 
-/* symbolic verbosity */
+/* named-symbolic input, independent bits */
+enum cat_disjoint_names { LOW = 10, MID, HI };
+
+/* named-symbolic verbosity */
 enum cat_level_names { L0 = 22, L1, L2, L3, L4, L5, L6, L7 };
-DECLARE_DYNDBG_CLASSMAP(map_level_names, DD_CLASS_TYPE_LEVEL_NAMES, 22,
-			"L0", "L1", "L2", "L3", "L4", "L5", "L6", "L7");
-DD_SYS_WRAP(level_names, p);
-DD_SYS_WRAP(level_names, T);
+
+/* recapitulate DRM's parent(drm.ko) <-- _submod(drivers,helpers) */
+#if !defined(TEST_DYNAMIC_DEBUG_SUBMOD)
+/*
+ * In single user, or parent / coordinator (drm.ko) modules, define
+ * classmaps on the client enums above, and then declares the PARAMS
+ * ref'g the classmaps.  Each is exported.
+ */
+DYNDBG_CLASSMAP_DEFINE(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS,
+		       D2_CORE,
+		       "D2_CORE",
+		       "D2_DRIVER",
+		       "D2_KMS",
+		       "D2_PRIME",
+		       "D2_ATOMIC",
+		       "D2_VBL",
+		       "D2_STATE",
+		       "D2_LEASE",
+		       "D2_DP",
+		       "D2_DRMRES");
+
+DYNDBG_CLASSMAP_DEFINE(map_level_num, DD_CLASS_TYPE_LEVEL_NUM,
+		       V0, "V0", "V1", "V2", "V3", "V4", "V5", "V6", "V7");
+
+/*
+ * now add the sysfs-params
+ */
+
+DYNDBG_CLASSMAP_PARAM(disjoint_bits, p);
+DYNDBG_CLASSMAP_PARAM(level_num, p);
+
+#else /* TEST_DYNAMIC_DEBUG_SUBMOD */
+
+/*
+ * in submod/drm-drivers, use the classmaps defined in top/parent
+ * module above.
+ */
+
+DYNDBG_CLASSMAP_USE(map_disjoint_bits);
+DYNDBG_CLASSMAP_USE(map_level_num);
+
+#endif
 
 /* stand-in for all pr_debug etc */
 #define prdbg(SYM) __pr_debug_cls(SYM, #SYM " msg\n")
@@ -129,6 +165,7 @@ static void do_levels(void)
 
 static void do_prints(void)
 {
+	pr_debug("do_prints:\n");
 	do_cats();
 	do_levels();
 }
diff --git a/lib/test_dynamic_debug_submod.c b/lib/test_dynamic_debug_submod.c
new file mode 100644
index 000000000000..9a893402ce1a
--- /dev/null
+++ b/lib/test_dynamic_debug_submod.c
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Kernel module for testing dynamic_debug
+ *
+ * Authors:
+ *      Jim Cromie	<jim.cromie@gmail.com>
+ */
+
+#define TEST_DYNAMIC_DEBUG_SUBMOD
+#include "test_dynamic_debug.c"
-- 
2.41.0

[PATCH v5 15/23] dyndbg: add for_each_boxed_vector

[Jim Cromie]

Add a for_each iterator to walk a counted vector member in a struct
(ie the box), and use it to replace 8 open-coded loops.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
v5- parens-on-box-force-precedence
---
 lib/dynamic_debug.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index e10fe6ed29cc..63cf14dc3e9f 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -157,6 +157,9 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 		  _dt->num_class_users);				\
 	})
 
+#define for_each_boxed_vector(_box, _vec, _len, _ct, _curs)		\
+	for (_ct = 0, _curs = (_box)->_vec; _ct < (_box)->_len; _ct++, _curs++)
+
 #define __outvar /* filled by callee */
 static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
 							const char *class_string,
@@ -166,7 +169,7 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons
 	struct ddebug_class_user *cli;
 	int i, idx;
 
-	for (i = 0, map = dt->classes; i < dt->num_classes; i++, map++) {
+	for_each_boxed_vector(dt, classes, num_classes, i, map) {
 		idx = match_string(map->class_names, map->length, class_string);
 		if (idx >= 0) {
 			*class_id = idx + map->base;
@@ -174,7 +177,7 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons
 			return map;
 		}
 	}
-	for (i = 0, cli = dt->class_users; i < dt->num_class_users; i++, cli++) {
+	for_each_boxed_vector(dt, class_users, num_class_users, i, cli) {
 		idx = match_string(cli->map->class_names, cli->map->length, class_string);
 		if (idx >= 0) {
 			*class_id = idx + cli->map->base;
@@ -1054,11 +1057,11 @@ static const char *ddebug_class_name(struct ddebug_table *dt, struct _ddebug *dp
 	struct ddebug_class_user *cli = dt->class_users;
 	int i;
 
-	for (i = 0; i < dt->num_classes; i++, map++)
+	for_each_boxed_vector(dt, classes, num_classes, i, map)
 		if (class_in_range(dp->class_id, map))
 			return map->class_names[dp->class_id - map->base];
 
-	for (i = 0; i < dt->num_class_users; i++, cli++)
+	for_each_boxed_vector(dt, class_users, num_class_users, i, cli)
 		if (class_in_range(dp->class_id, cli->map))
 			return cli->map->class_names[dp->class_id - cli->map->base];
 
@@ -1212,7 +1215,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
 	struct ddebug_class_map *cm;
 	int i, nc = 0;
 
-	for (i = 0, cm = di->classes; i < di->num_classes; i++, cm++) {
+	for_each_boxed_vector(di, classes, num_classes, i, cm) {
 
 		if (!strcmp(cm->mod_name, dt->mod_name)) {
 			vpr_cm_info(cm, "classes[%d]:", i);
@@ -1225,7 +1228,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
 		vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
 
 	/* now iterate dt */
-	for (i = 0, cm = dt->classes; i < dt->num_classes; i++, cm++)
+	for_each_boxed_vector(di, classes, num_classes, i, cm)
 		ddebug_apply_params(cm, cm->mod_name);
 }
 
@@ -1245,7 +1248,7 @@ static void ddebug_attach_user_module_classes(struct ddebug_table *dt,
 	 * module's refs, save to dt.  For loadables, this is the
 	 * whole array.
 	 */
-	for (i = 0, cli = di->class_users; i < di->num_class_users; i++, cli++) {
+	for_each_boxed_vector(di, class_users, num_class_users, i, cli) {
 
 		if (WARN_ON(!cli || !cli->map || !cli->user_mod_name))
 			continue;
@@ -1260,8 +1263,7 @@ static void ddebug_attach_user_module_classes(struct ddebug_table *dt,
 	}
 	dt->num_class_users = nc;
 
-	/* now iterate dt */
-	for (i = 0, cli = dt->class_users; i < dt->num_class_users; i++, cli++)
+	for_each_boxed_vector(di, class_users, num_class_users, i, cli)
 		ddebug_apply_params(cli->map, cli->user_mod_name);
 
 	vpr_dt_info(dt, "attach-client-module: ");
-- 
2.41.0

[PATCH v5 16/23] dyndbg: refactor ddebug_classparam_clamp_input

[Jim Cromie]

Extract input validation code, from param_set_dyndbg_module_classes()
(the sys-node >handler) to new: ddebug_classparam_clamp_input(kp),
call it from former.  It takes kernel-param arg, so it can complain
about "foo: bad input".

Reuse ddparam_clamp_input(kp) in ddebug_sync_classbits(),
to validate inputs from parent's params, just like our own.
To support that reuse, alter ddebug_sync_classbits() and caller to
pass kp instead of kp->arg.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 66 ++++++++++++++++++++++++++++++---------------
 1 file changed, 45 insertions(+), 21 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 63cf14dc3e9f..afcfeffde1d7 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -655,6 +655,30 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 
 #define CLASSMAP_BITMASK(width) ((1UL << (width)) - 1)
 
+static void ddebug_class_param_clamp_input(unsigned long *inrep, const struct kernel_param *kp)
+{
+	const struct ddebug_class_param *dcp = kp->arg;
+	const struct ddebug_class_map *map = dcp->map;
+
+	switch (map->map_type) {
+	case DD_CLASS_TYPE_DISJOINT_BITS:
+		/* expect bits. mask and warn if too many */
+		if (*inrep & ~CLASSMAP_BITMASK(map->length)) {
+			pr_warn("%s: input: 0x%lx exceeds mask: 0x%lx, masking\n",
+				KP_NAME(kp), *inrep, CLASSMAP_BITMASK(map->length));
+			*inrep &= CLASSMAP_BITMASK(map->length);
+		}
+		break;
+	case DD_CLASS_TYPE_LEVEL_NUM:
+		/* input is bitpos, of highest verbosity to be enabled */
+		if (*inrep > map->length) {
+			pr_warn("%s: level:%ld exceeds max:%d, clamping\n",
+				KP_NAME(kp), *inrep, map->length);
+			*inrep = map->length;
+		}
+		break;
+	}
+}
 static int param_set_dyndbg_module_classes(const char *instr,
 					   const struct kernel_param *kp,
 					   const char *modnm)
@@ -673,26 +697,15 @@ static int param_set_dyndbg_module_classes(const char *instr,
 		pr_err("expecting numeric input, not: %s > %s\n", instr, KP_NAME(kp));
 		return -EINVAL;
 	}
+	ddebug_class_param_clamp_input(&inrep, kp);
 
 	switch (map->map_type) {
 	case DD_CLASS_TYPE_DISJOINT_BITS:
-		/* expect bits. mask and warn if too many */
-		if (inrep & ~CLASSMAP_BITMASK(map->length)) {
-			pr_warn("%s: input: 0x%lx exceeds mask: 0x%lx, masking\n",
-				KP_NAME(kp), inrep, CLASSMAP_BITMASK(map->length));
-			inrep &= CLASSMAP_BITMASK(map->length);
-		}
 		v2pr_info("bits:0x%lx > %s.%s\n", inrep, modnm ?: "*", KP_NAME(kp));
 		totct += ddebug_apply_class_bitmap(dcp, &inrep, *dcp->bits, modnm);
 		*dcp->bits = inrep;
 		break;
 	case DD_CLASS_TYPE_LEVEL_NUM:
-		/* input is bitpos, of highest verbosity to be enabled */
-		if (inrep > map->length) {
-			pr_warn("%s: level:%ld exceeds max:%d, clamping\n",
-				KP_NAME(kp), inrep, map->length);
-			inrep = map->length;
-		}
 		old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 		new_bits = CLASSMAP_BITMASK(inrep);
 		v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
@@ -1156,16 +1169,27 @@ static const char * const ddebug_classmap_typenames[] = {
 		  ddebug_classmap_typenames[_cm->map_type]);		\
 	})
 
-static void ddebug_sync_classbits(const struct ddebug_class_param *dcp, const char *modname)
+static void ddebug_sync_classbits(const struct kernel_param *kp, const char *modname)
 {
-	/* clamp initial bitvec, mask off hi-bits */
-	if (*dcp->bits & ~CLASSMAP_BITMASK(dcp->map->length)) {
-		*dcp->bits &= CLASSMAP_BITMASK(dcp->map->length);
-		v2pr_info("preset classbits: %lx\n", *dcp->bits);
+	struct ddebug_class_param *dcp = kp->arg;
+	unsigned long new_bits;
+
+	ddebug_class_param_clamp_input(dcp->bits, kp);
+
+	switch (dcp->map->map_type) {
+	case DD_CLASS_TYPE_DISJOINT_BITS:
+		v2pr_info("%s: classbits: 0x%lx\n", KP_NAME(kp), *dcp->bits);
+		ddebug_apply_class_bitmap(dcp, dcp->bits, 0UL, modname);
+		break;
+	case DD_CLASS_TYPE_LEVEL_NUM:
+		new_bits = CLASSMAP_BITMASK(*dcp->lvl);
+		v2pr_info("%s: lvl:%ld bits:0x%lx\n", KP_NAME(kp), *dcp->lvl, new_bits);
+		ddebug_apply_class_bitmap(dcp, &new_bits, 0UL, modname);
+		break;
+	default:
+		pr_err("bad map type %d\n", dcp->map->map_type);
+		return;
 	}
-	/* force class'd prdbgs (in USEr module) to match (DEFINEr module) class-param */
-	ddebug_apply_class_bitmap(dcp, dcp->bits, ~0, modname);
-	ddebug_apply_class_bitmap(dcp, dcp->bits, 0, modname);
 }
 
 static void ddebug_match_apply_kparam(const struct kernel_param *kp,
@@ -1182,7 +1206,7 @@ static void ddebug_match_apply_kparam(const struct kernel_param *kp,
 	if (map == dcp->map) {
 		v2pr_info("found kp:%s =0x%lx", kp->name, *dcp->bits);
 		vpr_cm_info(map, "mapped to:");
-		ddebug_sync_classbits(dcp, modnm);
+		ddebug_sync_classbits(kp, modnm);
 	}
 }
 
-- 
2.41.0

[PATCH v5 17/23] dyndbg-API: promote DYNDBG_CLASSMAP_PARAM to API

[Jim Cromie]

move macro from test-dynamic-debug.c into header, and refine it.

Distinguish the 2 use cases of DYNDBG_CLASSMAP_PARAM*

1.DYNDBG_CLASSMAP_PARAM_REF
    for DRM, to pass in extern __drm_debug by name.
    dyndbg keeps bits in it, so drm can still use it as before

2.DYNDBG_CLASSMAP_PARAM
    new user (test_dynamic_debug) doesn't need to share state,
    decls a static long unsigned int to store the bitvec.

__DYNDBG_CLASSMAP_PARAM
   bottom layer - allocate,init a ddebug-class-param, module-param-cb.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 drivers/gpu/drm/drm_print.c   |  8 ++-----
 include/drm/drm_print.h       |  6 ++++--
 include/linux/dynamic_debug.h | 39 +++++++++++++++++++++++++++++++++--
 lib/test_dynamic_debug.c      | 22 +++-----------------
 4 files changed, 46 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
index dabcfa0dd279..8f4b609353a5 100644
--- a/drivers/gpu/drm/drm_print.c
+++ b/drivers/gpu/drm/drm_print.c
@@ -69,12 +69,8 @@ DRM_CLASSMAP_DEFINE(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS,
 		    "DRM_UT_DP",
 		    "DRM_UT_DRMRES");
 
-static struct ddebug_class_param drm_debug_bitmap = {
-	.bits = &__drm_debug,
-	.flags = "p",
-	.map = &drm_debug_classes,
-};
-module_param_cb(debug, &param_ops_dyndbg_classes, &drm_debug_bitmap, 0600);
+DRM_CLASSMAP_PARAM_REF(debug, __drm_debug, drm_debug_classes, p);
+
 #endif
 
 void __drm_puts_coredump(struct drm_printer *p, const char *str)
diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index 706afc97c79c..94d4f5500030 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -322,11 +322,13 @@ enum drm_debug_category {
 };
 
 #ifdef CONFIG_DRM_USE_DYNAMIC_DEBUG
-#define DRM_CLASSMAP_DEFINE(...) DYNDBG_CLASSMAP_DEFINE(__VA_ARGS__)
-#define DRM_CLASSMAP_USE(name)   DYNDBG_CLASSMAP_USE(name)
+#define DRM_CLASSMAP_DEFINE(...)	DYNDBG_CLASSMAP_DEFINE(__VA_ARGS__)
+#define DRM_CLASSMAP_USE(name)		DYNDBG_CLASSMAP_USE(name)
+#define DRM_CLASSMAP_PARAM_REF(...)	DYNDBG_CLASSMAP_PARAM_REF(__VA_ARGS__)
 #else
 #define DRM_CLASSMAP_DEFINE(...)
 #define DRM_CLASSMAP_USE(name)
+#define DRM_CLASSMAP_PARAM_REF(...)
 #endif
 
 static inline bool drm_debug_enabled_raw(enum drm_debug_category category)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 85f9b91034ca..871de0c32034 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -90,7 +90,7 @@ struct ddebug_class_map {
  * module, and to validate inputs to DD_CLASS_TYPE_*_NAMES typed params.
  */
 #define DYNDBG_CLASSMAP_DEFINE(_var, _maptype, _base, ...)		\
-	const char *_var##_classnames[] = { __VA_ARGS__ };		\
+	static const char *_var##_classnames[] = { __VA_ARGS__ };	\
 	struct ddebug_class_map __aligned(8) __used			\
 		__section("__dyndbg_classes") _var = {			\
 		.mod = THIS_MODULE,					\
@@ -119,7 +119,7 @@ struct ddebug_class_user {
 	DYNDBG_CLASSMAP_USE_(_var, __UNIQUE_ID(ddebug_class_user))
 #define DYNDBG_CLASSMAP_USE_(_var, _uname)				\
 	extern struct ddebug_class_map _var;				\
-	struct ddebug_class_user __used					\
+	static struct ddebug_class_user __used				\
 	__section("__dyndbg_class_users") _uname = {			\
 		.user_mod_name = KBUILD_MODNAME,			\
 		.map = &_var,						\
@@ -144,6 +144,41 @@ struct ddebug_class_param {
 	const struct ddebug_class_map *map;
 };
 
+/**
+ * DYNDBG_CLASSMAP_PARAM - wrap a dyndbg-classmap with a controlling sys-param
+ * @_name  sysfs node name
+ * @_var   name of the struct classmap var defining the controlled classes
+ * @_flags flags to be toggled, typically just 'p'
+ *
+ * Creates a sysfs-param to control the classes defined by the
+ * classmap.  Keeps bits in a private/static
+ */
+#define DYNDBG_CLASSMAP_PARAM(_name, _var, _flags)			\
+	static unsigned long _name##_bvec;				\
+	__DYNDBG_CLASSMAP_PARAM(_name, _name##_bvec, _var, _flags)
+
+/**
+ * DYNDBG_CLASSMAP_PARAM_REF - wrap a dyndbg-classmap with a controlling sys-param
+ * @_name  sysfs node name
+ * @_bits  name of the module's unsigned long bit-vector, ex: __drm_debug
+ * @_var   name of the struct classmap var defining the controlled classes
+ * @_flags flags to be toggled, typically just 'p'
+ *
+ * Creates a sysfs-param to control the classmap, keeping bitvec in user @_bits.
+ * This lets drm use __drm_debug elsewhere too.
+ */
+#define DYNDBG_CLASSMAP_PARAM_REF(_name, _bits, _var, _flags)		\
+	__DYNDBG_CLASSMAP_PARAM(_name, _bits, _var, _flags)
+
+#define __DYNDBG_CLASSMAP_PARAM(_name, _bits, _var, _flags)		\
+	static struct ddebug_class_param _name##_##_flags = {		\
+		.bits = &_bits,						\
+		.flags = #_flags,					\
+		.map = &_var,						\
+	};								\
+	module_param_cb(_name, &param_ops_dyndbg_classes,		\
+			&_name##_##_flags, 0600)
+
 /*
  * pr_debug() and friends are globally enabled or modules have selectively
  * enabled them.
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 23967071b60f..df41963d9faf 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -35,22 +35,6 @@ module_param_cb(do_prints, &param_ops_do_prints, NULL, 0600);
 
 #define CLASSMAP_BITMASK(width, base) (((1UL << (width)) - 1) << base)
 
-/* sysfs param wrapper, proto-API */
-#define DYNDBG_CLASSMAP_PARAM_(_model, _flags, _init)			\
-	static unsigned long bits_##_model = _init;			\
-	static struct ddebug_class_param _flags##_##_model = {		\
-		.bits = &bits_##_model,					\
-		.flags = #_flags,					\
-		.map = &map_##_model,					\
-	};								\
-	module_param_cb(_flags##_##_model, &param_ops_dyndbg_classes,	\
-			&_flags##_##_model, 0600)
-#ifdef DEBUG
-#define DYNDBG_CLASSMAP_PARAM(_model, _flags)  DYNDBG_CLASSMAP_PARAM_(_model, _flags, ~0)
-#else
-#define DYNDBG_CLASSMAP_PARAM(_model, _flags)  DYNDBG_CLASSMAP_PARAM_(_model, _flags, 0)
-#endif
-
 /*
  * Demonstrate/test all 4 class-typed classmaps with a sys-param.
  *
@@ -113,11 +97,11 @@ DYNDBG_CLASSMAP_DEFINE(map_level_num, DD_CLASS_TYPE_LEVEL_NUM,
 		       V0, "V0", "V1", "V2", "V3", "V4", "V5", "V6", "V7");
 
 /*
- * now add the sysfs-params
+ * now add the sysfs-params: name, classmap, flags-toggled
  */
 
-DYNDBG_CLASSMAP_PARAM(disjoint_bits, p);
-DYNDBG_CLASSMAP_PARAM(level_num, p);
+DYNDBG_CLASSMAP_PARAM(p_disjoint_bits,	map_disjoint_bits, p);
+DYNDBG_CLASSMAP_PARAM(p_level_num,	map_level_num, p);
 
 #else /* TEST_DYNAMIC_DEBUG_SUBMOD */
 
-- 
2.41.0

[PATCH v5 18/22] dyndbg-test: build it with just CONFIG_DYNAMIC_DEBUG_CORE

[Jim Cromie]

Make the test-module buildable with CONFIG_DYNAMIC_DEBUG_CORE; add
CFLAGS_$ofile defns to supply -DDYNAMIC_DEBUG_MODULE to cc.  Change
the Kconfig entry to allow building with just _CORE, and fix the help
text.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/Kconfig.debug | 10 +++++-----
 lib/Makefile      |  2 ++
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index ce51d4dc6803..22e022ceb9a1 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2695,12 +2695,12 @@ config TEST_STATIC_KEYS
 	  If unsure, say N.
 
 config TEST_DYNAMIC_DEBUG
-	tristate "Test DYNAMIC_DEBUG"
-	depends on DYNAMIC_DEBUG
+	tristate "Build test-dynamic-debug module"
+	depends on DYNAMIC_DEBUG || DYNAMIC_DEBUG_CORE
 	help
-	  This module registers a tracer callback to count enabled
-	  pr_debugs in a 'do_debugging' function, then alters their
-	  enablements, calls the function, and compares counts.
+	  This module works/demo's the dyndbg's classmap API, by
+	  creating 2 classes: a DISJOINT classmap (like DRM.debug)
+	  and a LEVELS/VERBOSE classmap (like verbose2 > verbose1).
 
 	  If unsure, say N.
 
diff --git a/lib/Makefile b/lib/Makefile
index f36048371dd2..8411015a57c1 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -233,6 +233,8 @@ obj-$(CONFIG_HAVE_ARCH_TRACEHOOK) += syscall.o
 obj-$(CONFIG_DYNAMIC_DEBUG_CORE) += dynamic_debug.o
 #ensure exported functions have prototypes
 CFLAGS_dynamic_debug.o := -DDYNAMIC_DEBUG_MODULE
+CFLAGS_test_dynamic_debug.o := -DDYNAMIC_DEBUG_MODULE
+CFLAGS_test_dynamic_debug_submod.o := -DDYNAMIC_DEBUG_MODULE
 
 obj-$(CONFIG_SYMBOLIC_ERRNAME) += errname.o
 
-- 
2.41.0

[PATCH v5 18/23] parens-on-PARAM

[Jim Cromie]

---
 include/linux/dynamic_debug.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 871de0c32034..9b86c49173f9 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -172,9 +172,9 @@ struct ddebug_class_param {
 
 #define __DYNDBG_CLASSMAP_PARAM(_name, _bits, _var, _flags)		\
 	static struct ddebug_class_param _name##_##_flags = {		\
-		.bits = &_bits,						\
+		.bits = &(_bits),					\
 		.flags = #_flags,					\
-		.map = &_var,						\
+		.map = &(_var),						\
 	};								\
 	module_param_cb(_name, &param_ops_dyndbg_classes,		\
 			&_name##_##_flags, 0600)
-- 
2.41.0

[PATCH v5 19/22] drm: restore CONFIG_DRM_USE_DYNAMIC_DEBUG un-BROKEN

[Jim Cromie]

Lots of burn-in testing needed before signing, upstreaming.

NOTE: I set default Y to maximize testing by default.
Is there a better way to do this ?

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 drivers/gpu/drm/Kconfig | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index ba3fb04bb691..ff478fcba67e 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -52,8 +52,7 @@ config DRM_DEBUG_MM
 
 config DRM_USE_DYNAMIC_DEBUG
 	bool "use dynamic debug to implement drm.debug"
-	default n
-	depends on BROKEN
+	default y
 	depends on DRM
 	depends on DYNAMIC_DEBUG || DYNAMIC_DEBUG_CORE
 	depends on JUMP_LABEL
-- 
2.41.0

[PATCH v5 19/23] dyndbg-test: build it with just CONFIG_DYNAMIC_DEBUG_CORE

[Jim Cromie]

Make the test-module buildable with CONFIG_DYNAMIC_DEBUG_CORE; add
CFLAGS_$ofile defns to supply -DDYNAMIC_DEBUG_MODULE to cc.  Change
the Kconfig entry to allow building with just _CORE, and fix the help
text.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/Kconfig.debug | 10 +++++-----
 lib/Makefile      |  2 ++
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index ce51d4dc6803..22e022ceb9a1 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2695,12 +2695,12 @@ config TEST_STATIC_KEYS
 	  If unsure, say N.
 
 config TEST_DYNAMIC_DEBUG
-	tristate "Test DYNAMIC_DEBUG"
-	depends on DYNAMIC_DEBUG
+	tristate "Build test-dynamic-debug module"
+	depends on DYNAMIC_DEBUG || DYNAMIC_DEBUG_CORE
 	help
-	  This module registers a tracer callback to count enabled
-	  pr_debugs in a 'do_debugging' function, then alters their
-	  enablements, calls the function, and compares counts.
+	  This module works/demo's the dyndbg's classmap API, by
+	  creating 2 classes: a DISJOINT classmap (like DRM.debug)
+	  and a LEVELS/VERBOSE classmap (like verbose2 > verbose1).
 
 	  If unsure, say N.
 
diff --git a/lib/Makefile b/lib/Makefile
index f36048371dd2..8411015a57c1 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -233,6 +233,8 @@ obj-$(CONFIG_HAVE_ARCH_TRACEHOOK) += syscall.o
 obj-$(CONFIG_DYNAMIC_DEBUG_CORE) += dynamic_debug.o
 #ensure exported functions have prototypes
 CFLAGS_dynamic_debug.o := -DDYNAMIC_DEBUG_MODULE
+CFLAGS_test_dynamic_debug.o := -DDYNAMIC_DEBUG_MODULE
+CFLAGS_test_dynamic_debug_submod.o := -DDYNAMIC_DEBUG_MODULE
 
 obj-$(CONFIG_SYMBOLIC_ERRNAME) += errname.o
 
-- 
2.41.0

[PATCH v5 20/22] drm-drivers: DRM_CLASSMAP_USE in 2nd batch of drivers, helpers

[Jim Cromie]

Add a DRM_CLASSMAP_USE declaration to 2nd batch of helpers and *_drv.c
files.  For drivers, add the decl just above the module's PARAMs,
since it identifies the "inherited" drm.debug param.

Note: with CONFIG_DRM_USE_DYNAMIC_DEBUG=y, a module not also declaring
DRM_CLASSMAP_USE will have its class'd prdbgs stuck in the initial
(disabled, but for DEBUG) state.

The stuck sites are evident in /proc/dynamic_debug/control as:

   class unknown, _id:N		# control's last column

rather than a proper "enumeration":

   class:DRM_UT_CORE

This set of updates was found by choosing M for all DRM-config items I
found (not allmodconfig), building & modprobing them, and grepping
"class unknown," control.  There may yet be others.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 drivers/gpu/drm/drm_gem_shmem_helper.c | 2 ++
 drivers/gpu/drm/gud/gud_drv.c          | 2 ++
 drivers/gpu/drm/mgag200/mgag200_drv.c  | 2 ++
 drivers/gpu/drm/qxl/qxl_drv.c          | 2 ++
 drivers/gpu/drm/radeon/radeon_drv.c    | 2 ++
 drivers/gpu/drm/udl/udl_main.c         | 2 ++
 drivers/gpu/drm/vkms/vkms_drv.c        | 2 ++
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c    | 2 ++
 8 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 4ea6507a77e5..5e02df98327b 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -23,6 +23,8 @@
 #include <drm/drm_prime.h>
 #include <drm/drm_print.h>
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 MODULE_IMPORT_NS(DMA_BUF);
 
 /**
diff --git a/drivers/gpu/drm/gud/gud_drv.c b/drivers/gpu/drm/gud/gud_drv.c
index 9d7bf8ee45f1..5b555045fce4 100644
--- a/drivers/gpu/drm/gud/gud_drv.c
+++ b/drivers/gpu/drm/gud/gud_drv.c
@@ -31,6 +31,8 @@
 
 #include "gud_internal.h"
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 /* Only used internally */
 static const struct drm_format_info gud_drm_format_r1 = {
 	.format = GUD_DRM_FORMAT_R1,
diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.c b/drivers/gpu/drm/mgag200/mgag200_drv.c
index 976f0ab2006b..a1b2be1c27f6 100644
--- a/drivers/gpu/drm/mgag200/mgag200_drv.c
+++ b/drivers/gpu/drm/mgag200/mgag200_drv.c
@@ -24,6 +24,8 @@ int mgag200_modeset = -1;
 MODULE_PARM_DESC(modeset, "Disable/Enable modesetting");
 module_param_named(modeset, mgag200_modeset, int, 0400);
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 int mgag200_init_pci_options(struct pci_dev *pdev, u32 option, u32 option2)
 {
 	struct device *dev = &pdev->dev;
diff --git a/drivers/gpu/drm/qxl/qxl_drv.c b/drivers/gpu/drm/qxl/qxl_drv.c
index a3b83f89e061..12600f557c23 100644
--- a/drivers/gpu/drm/qxl/qxl_drv.c
+++ b/drivers/gpu/drm/qxl/qxl_drv.c
@@ -65,6 +65,8 @@ module_param_named(modeset, qxl_modeset, int, 0400);
 MODULE_PARM_DESC(num_heads, "Number of virtual crtcs to expose (default 4)");
 module_param_named(num_heads, qxl_num_crtc, int, 0400);
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 static struct drm_driver qxl_driver;
 static struct pci_driver qxl_pci_driver;
 
diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
index e4374814f0ef..4219276ade6a 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.c
+++ b/drivers/gpu/drm/radeon/radeon_drv.c
@@ -274,6 +274,8 @@ int radeon_cik_support = 1;
 MODULE_PARM_DESC(cik_support, "CIK support (1 = enabled (default), 0 = disabled)");
 module_param_named(cik_support, radeon_cik_support, int, 0444);
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 static struct pci_device_id pciidlist[] = {
 	radeon_PCI_IDS
 };
diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c
index 061cb88c08a2..8f9dfe89f64a 100644
--- a/drivers/gpu/drm/udl/udl_main.c
+++ b/drivers/gpu/drm/udl/udl_main.c
@@ -19,6 +19,8 @@
 
 #define NR_USB_REQUEST_CHANNEL 0x12
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 #define MAX_TRANSFER (PAGE_SIZE*16 - BULK_SIZE)
 #define WRITES_IN_FLIGHT (20)
 #define MAX_VENDOR_DESCRIPTOR_SIZE 256
diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
index 6d3a2d57d992..086a9933fcdf 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.c
+++ b/drivers/gpu/drm/vkms/vkms_drv.c
@@ -39,6 +39,8 @@
 
 static struct vkms_config *default_config;
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 static bool enable_cursor = true;
 module_param_named(enable_cursor, enable_cursor, bool, 0444);
 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 8b24ecf60e3e..9cb6be422621 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -275,6 +275,8 @@ static int vmw_probe(struct pci_dev *, const struct pci_device_id *);
 static int vmwgfx_pm_notifier(struct notifier_block *nb, unsigned long val,
 			      void *ptr);
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 MODULE_PARM_DESC(restrict_iommu, "Try to limit IOMMU usage for TTM pages");
 module_param_named(restrict_iommu, vmw_restrict_iommu, int, 0600);
 MODULE_PARM_DESC(force_coherent, "Force coherent TTM pages");
-- 
2.41.0

[PATCH v5 20/23] drm: restore CONFIG_DRM_USE_DYNAMIC_DEBUG un-BROKEN

[Jim Cromie]

Lots of burn-in testing needed before signing, upstreaming.

NOTE: I set default Y to maximize testing by default.
Is there a better way to do this ?

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 drivers/gpu/drm/Kconfig | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index ba3fb04bb691..ff478fcba67e 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -52,8 +52,7 @@ config DRM_DEBUG_MM
 
 config DRM_USE_DYNAMIC_DEBUG
 	bool "use dynamic debug to implement drm.debug"
-	default n
-	depends on BROKEN
+	default y
 	depends on DRM
 	depends on DYNAMIC_DEBUG || DYNAMIC_DEBUG_CORE
 	depends on JUMP_LABEL
-- 
2.41.0

[PATCH v5 21/23] drm-drivers: DRM_CLASSMAP_USE in 2nd batch of drivers, helpers

[Jim Cromie]

Add a DRM_CLASSMAP_USE declaration to 2nd batch of helpers and *_drv.c
files.  For drivers, add the decl just above the module's PARAMs,
since it identifies the "inherited" drm.debug param.

Note: with CONFIG_DRM_USE_DYNAMIC_DEBUG=y, a module not also declaring
DRM_CLASSMAP_USE will have its class'd prdbgs stuck in the initial
(disabled, but for DEBUG) state.

The stuck sites are evident in /proc/dynamic_debug/control as:

   class unknown, _id:N		# control's last column

rather than a proper "enumeration":

   class:DRM_UT_CORE

This set of updates was found by choosing M for all DRM-config items I
found (not allmodconfig), building & modprobing them, and grepping
"class unknown," control.  There may yet be others.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 drivers/gpu/drm/drm_gem_shmem_helper.c | 2 ++
 drivers/gpu/drm/gud/gud_drv.c          | 2 ++
 drivers/gpu/drm/mgag200/mgag200_drv.c  | 2 ++
 drivers/gpu/drm/qxl/qxl_drv.c          | 2 ++
 drivers/gpu/drm/radeon/radeon_drv.c    | 2 ++
 drivers/gpu/drm/udl/udl_main.c         | 2 ++
 drivers/gpu/drm/vkms/vkms_drv.c        | 2 ++
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c    | 2 ++
 8 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 4ea6507a77e5..5e02df98327b 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -23,6 +23,8 @@
 #include <drm/drm_prime.h>
 #include <drm/drm_print.h>
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 MODULE_IMPORT_NS(DMA_BUF);
 
 /**
diff --git a/drivers/gpu/drm/gud/gud_drv.c b/drivers/gpu/drm/gud/gud_drv.c
index 9d7bf8ee45f1..5b555045fce4 100644
--- a/drivers/gpu/drm/gud/gud_drv.c
+++ b/drivers/gpu/drm/gud/gud_drv.c
@@ -31,6 +31,8 @@
 
 #include "gud_internal.h"
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 /* Only used internally */
 static const struct drm_format_info gud_drm_format_r1 = {
 	.format = GUD_DRM_FORMAT_R1,
diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.c b/drivers/gpu/drm/mgag200/mgag200_drv.c
index 976f0ab2006b..a1b2be1c27f6 100644
--- a/drivers/gpu/drm/mgag200/mgag200_drv.c
+++ b/drivers/gpu/drm/mgag200/mgag200_drv.c
@@ -24,6 +24,8 @@ int mgag200_modeset = -1;
 MODULE_PARM_DESC(modeset, "Disable/Enable modesetting");
 module_param_named(modeset, mgag200_modeset, int, 0400);
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 int mgag200_init_pci_options(struct pci_dev *pdev, u32 option, u32 option2)
 {
 	struct device *dev = &pdev->dev;
diff --git a/drivers/gpu/drm/qxl/qxl_drv.c b/drivers/gpu/drm/qxl/qxl_drv.c
index a3b83f89e061..12600f557c23 100644
--- a/drivers/gpu/drm/qxl/qxl_drv.c
+++ b/drivers/gpu/drm/qxl/qxl_drv.c
@@ -65,6 +65,8 @@ module_param_named(modeset, qxl_modeset, int, 0400);
 MODULE_PARM_DESC(num_heads, "Number of virtual crtcs to expose (default 4)");
 module_param_named(num_heads, qxl_num_crtc, int, 0400);
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 static struct drm_driver qxl_driver;
 static struct pci_driver qxl_pci_driver;
 
diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
index e4374814f0ef..4219276ade6a 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.c
+++ b/drivers/gpu/drm/radeon/radeon_drv.c
@@ -274,6 +274,8 @@ int radeon_cik_support = 1;
 MODULE_PARM_DESC(cik_support, "CIK support (1 = enabled (default), 0 = disabled)");
 module_param_named(cik_support, radeon_cik_support, int, 0444);
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 static struct pci_device_id pciidlist[] = {
 	radeon_PCI_IDS
 };
diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c
index 061cb88c08a2..8f9dfe89f64a 100644
--- a/drivers/gpu/drm/udl/udl_main.c
+++ b/drivers/gpu/drm/udl/udl_main.c
@@ -19,6 +19,8 @@
 
 #define NR_USB_REQUEST_CHANNEL 0x12
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 #define MAX_TRANSFER (PAGE_SIZE*16 - BULK_SIZE)
 #define WRITES_IN_FLIGHT (20)
 #define MAX_VENDOR_DESCRIPTOR_SIZE 256
diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
index 6d3a2d57d992..086a9933fcdf 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.c
+++ b/drivers/gpu/drm/vkms/vkms_drv.c
@@ -39,6 +39,8 @@
 
 static struct vkms_config *default_config;
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 static bool enable_cursor = true;
 module_param_named(enable_cursor, enable_cursor, bool, 0444);
 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 8b24ecf60e3e..9cb6be422621 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -275,6 +275,8 @@ static int vmw_probe(struct pci_dev *, const struct pci_device_id *);
 static int vmwgfx_pm_notifier(struct notifier_block *nb, unsigned long val,
 			      void *ptr);
 
+DRM_CLASSMAP_USE(drm_debug_classes);
+
 MODULE_PARM_DESC(restrict_iommu, "Try to limit IOMMU usage for TTM pages");
 module_param_named(restrict_iommu, vmw_restrict_iommu, int, 0600);
 MODULE_PARM_DESC(force_coherent, "Force coherent TTM pages");
-- 
2.41.0

[PATCH v5 21/22] dyndbg-doc: add classmap info to howto

[Jim Cromie]

Add some basic info on classmap usage and api

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 .../admin-guide/dynamic-debug-howto.rst       | 64 ++++++++++++++++++-
 1 file changed, 63 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 8dc668cc1216..b8d2a7235cbb 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -224,7 +224,6 @@ the ``p`` flag has meaning, other flags are ignored.
 Note the regexp ``^[-+=][flmpt_]+$`` matches a flags specification.
 To clear all flags at once, use ``=_`` or ``-flmpt``.
 
-
 Debug messages during Boot Process
 ==================================
 
@@ -374,3 +373,66 @@ just a shortcut for ``print_hex_dump(KERN_DEBUG)``.
 For ``print_hex_dump_debug()``/``print_hex_dump_bytes()``, format string is
 its ``prefix_str`` argument, if it is constant string; or ``hexdump``
 in case ``prefix_str`` is built dynamically.
+
+Dynamic Debug classmaps
+=======================
+
+Dyndbg generally selects *prdbg* callsites using structural info:
+module, file, function, line.  Using classmaps, user modules can
+organize/select pr_debug()s as they like.
+
+- classes coordinates/spans multiple modules
+- complements the mod,file,func attrs
+- keeps pr_debug's 0-off-cost JUMP_LABEL goodness
+- isolates each from other class'd and un-class'd pr_debugs()
+  (one doesn't intermix 2 clients' bank accounts)
+
+  # IOW this doesn't change DRM.debug settings
+  #> echo -p > /proc/dynamic_debug/control
+
+  # change the classes by naming them explicitly (no wildcard here)
+  #> echo class DRM_UT_CORE +p > /proc/dynamic_debug/control
+
+To support DRM.debug (/sys/module/drm/parameters/debug), dyndbg
+provides DYNDBG_CLASSMAP_PARAM*.  It maps the categories/classes:
+DRM_UT_CORE.. to bits 0..N, allowing to set all classes at once.
+
+Dynamic Debug Classmap API
+==========================
+
+DYNDBG_CLASSMAP_DEFINE - modules create CLASSMAPs, naming the classes
+and type, and mapping the class-names to consecutive _class_ids.  By
+doing so, they tell dyndbg that they are using those class_ids, and
+authorize dyndbg to manipulate the callsites by their class-names.
+
+Its expected that client modules will follow the DRM.debug model:
+1. define their debug-classes using an enum type, where the enum
+symbol and its integer value define both the classnames and class-ids.
+2. use or macro-wrap __pr_debug_cls(ENUM_VAL, "hello world\n")
+
+There are 2 types of classmaps:
+
+ DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, like DRM.debug
+ DD_CLASS_TYPE_LEVEL_NUM: classes are relative, ordered (V3 > V2)
+
+Both these classmap-types use the class-names/ENUM_VALs to validate
+commands into >control.
+
+DYNDBG_CLASSMAP_PARAM - refers to a DEFINEd classmap, exposing the set
+of defined classes to manipulation as a group.  This interface
+enforces the relatedness of classes of DD_CLASS_TYPE_LEVEL_NUM typed
+classmaps; all classes are independent in the >control parser itself.
+
+DYNDBG_CLASSMAP_USE - drm drivers use the CLASSMAP that drm DEFINEs.
+This shares the classmap definition, authorizes coordinated changes
+amongst the CLASSMAP DEFINEr and multiple USErs, and tells dyndbg
+how to initialize the user's prdbgs at modprobe.
+
+Modules or module-groups (drm & drivers) can define multiple
+classmaps, as long as they share the limited 0..62 per-module-group
+_class_id range, without overlap.
+
+``#define DEBUG`` will enable all pr_debugs in scope, including any
+class'd ones (__pr_debug_cls(id,fmt..)).  This won't be reflected in
+the PARAM readback value, but the pr_debug callsites can be toggled
+into agreement with the param.
-- 
2.41.0

[PATCH v5 22/22] checkpatch: reword long-line warn about commit-msg

[Jim Cromie]

Reword the warning to complain about line length 1st, since thats
whats actually tested.

Cc: apw@canonical.com
Cc: joe@perches.com
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 scripts/checkpatch.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index f6b6b2a50dfe..31c55e3ece09 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3272,7 +3272,7 @@ sub process {
 					# A Fixes:, link or signature tag line
 		      $commit_log_possible_stack_dump)) {
 			WARN("COMMIT_LOG_LONG_LINE",
-			     "Possible unwrapped commit description (prefer a maximum 75 chars per line)\n" . $herecurr);
+			     "Prefer a maximum 75 chars per line (possible unwrapped commit description?)\n" . $herecurr);
 			$commit_log_long_line = 1;
 		}
 
-- 
2.41.0

[PATCH v5 22/23] dyndbg-doc: add classmap info to howto

[Jim Cromie]

Add some basic info on classmap usage and api

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
v5- adjustments per Randy Dunlap
---
 .../admin-guide/dynamic-debug-howto.rst       | 64 ++++++++++++++++++-
 1 file changed, 63 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 8dc668cc1216..b8d2a7235cbb 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -224,7 +224,6 @@ the ``p`` flag has meaning, other flags are ignored.
 Note the regexp ``^[-+=][flmpt_]+$`` matches a flags specification.
 To clear all flags at once, use ``=_`` or ``-flmpt``.
 
-
 Debug messages during Boot Process
 ==================================
 
@@ -374,3 +373,66 @@ just a shortcut for ``print_hex_dump(KERN_DEBUG)``.
 For ``print_hex_dump_debug()``/``print_hex_dump_bytes()``, format string is
 its ``prefix_str`` argument, if it is constant string; or ``hexdump``
 in case ``prefix_str`` is built dynamically.
+
+Dynamic Debug classmaps
+=======================
+
+Dyndbg generally selects *prdbg* callsites using structural info:
+module, file, function, line.  Using classmaps, user modules can
+organize/select pr_debug()s as they like.
+
+- classes coordinates/spans multiple modules
+- complements the mod,file,func attrs
+- keeps pr_debug's 0-off-cost JUMP_LABEL goodness
+- isolates each from other class'd and un-class'd pr_debugs()
+  (one doesn't intermix 2 clients' bank accounts)
+
+  # IOW this doesn't change DRM.debug settings
+  #> echo -p > /proc/dynamic_debug/control
+
+  # change the classes by naming them explicitly (no wildcard here)
+  #> echo class DRM_UT_CORE +p > /proc/dynamic_debug/control
+
+To support DRM.debug (/sys/module/drm/parameters/debug), dyndbg
+provides DYNDBG_CLASSMAP_PARAM*.  It maps the categories/classes:
+DRM_UT_CORE.. to bits 0..N, allowing to set all classes at once.
+
+Dynamic Debug Classmap API
+==========================
+
+DYNDBG_CLASSMAP_DEFINE - modules create CLASSMAPs, naming the classes
+and type, and mapping the class-names to consecutive _class_ids.  By
+doing so, they tell dyndbg that they are using those class_ids, and
+authorize dyndbg to manipulate the callsites by their class-names.
+
+Its expected that client modules will follow the DRM.debug model:
+1. define their debug-classes using an enum type, where the enum
+symbol and its integer value define both the classnames and class-ids.
+2. use or macro-wrap __pr_debug_cls(ENUM_VAL, "hello world\n")
+
+There are 2 types of classmaps:
+
+ DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, like DRM.debug
+ DD_CLASS_TYPE_LEVEL_NUM: classes are relative, ordered (V3 > V2)
+
+Both these classmap-types use the class-names/ENUM_VALs to validate
+commands into >control.
+
+DYNDBG_CLASSMAP_PARAM - refers to a DEFINEd classmap, exposing the set
+of defined classes to manipulation as a group.  This interface
+enforces the relatedness of classes of DD_CLASS_TYPE_LEVEL_NUM typed
+classmaps; all classes are independent in the >control parser itself.
+
+DYNDBG_CLASSMAP_USE - drm drivers use the CLASSMAP that drm DEFINEs.
+This shares the classmap definition, authorizes coordinated changes
+amongst the CLASSMAP DEFINEr and multiple USErs, and tells dyndbg
+how to initialize the user's prdbgs at modprobe.
+
+Modules or module-groups (drm & drivers) can define multiple
+classmaps, as long as they share the limited 0..62 per-module-group
+_class_id range, without overlap.
+
+``#define DEBUG`` will enable all pr_debugs in scope, including any
+class'd ones (__pr_debug_cls(id,fmt..)).  This won't be reflected in
+the PARAM readback value, but the pr_debug callsites can be toggled
+into agreement with the param.
-- 
2.41.0

[PATCH v5 23/23] checkpatch: reword long-line warn about commit-msg

[Jim Cromie]

Reword the warning to complain about line length 1st, since thats
whats actually tested.

Cc: apw@canonical.com
Cc: joe@perches.com
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 scripts/checkpatch.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index f6b6b2a50dfe..31c55e3ece09 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3272,7 +3272,7 @@ sub process {
 					# A Fixes:, link or signature tag line
 		      $commit_log_possible_stack_dump)) {
 			WARN("COMMIT_LOG_LONG_LINE",
-			     "Possible unwrapped commit description (prefer a maximum 75 chars per line)\n" . $herecurr);
+			     "Prefer a maximum 75 chars per line (possible unwrapped commit description?)\n" . $herecurr);
 			$commit_log_long_line = 1;
 		}
 
-- 
2.41.0

Re: [PATCH v5 22/22] checkpatch: reword long-line warn about commit-msg

[Joe Perches]

On Tue, 2023-08-01 at 17:35 -0600, Jim Cromie wrote:
> Reword the warning to complain about line length 1st, since thats
> whats actually tested.
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -3272,7 +3272,7 @@ sub process {
>  					# A Fixes:, link or signature tag line
>  		      $commit_log_possible_stack_dump)) {
>  			WARN("COMMIT_LOG_LONG_LINE",
> -			     "Possible unwrapped commit description (prefer a maximum 75 chars per line)\n" . $herecurr);
> +			     "Prefer a maximum 75 chars per line (possible unwrapped commit description?)\n" . $herecurr);
>  			$commit_log_long_line = 1;
>  		}

I don't think this adds any clarity.  Anyone else?