move the DYNDBG_CLASSMAP_PARAM macro from test-dynamic-debug.c into
the header, and refine it, by distinguishing the 2 use cases:
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.
Modify ddebug_sync_classbits() argtype deref inside the fn, to give
access to all kp members.
Also clean up and improve comments in test-code, and add
MODULE_DESCRIPTIONs.
Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
-v9
- fixup drm-print.h add PARAM_REF forwarding macros
with DYNDBG_CLASSMAP_PARAM_REF in the API, add DRM_ variant
---
include/linux/dynamic_debug.h | 38 +++++++++++++++++++++
lib/dynamic_debug.c | 60 ++++++++++++++++++++++-----------
lib/test_dynamic_debug.c | 59 +++++++++++++-------------------
lib/test_dynamic_debug_submod.c | 9 ++++-
4 files changed, 111 insertions(+), 55 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 48d76a273f68..b47d1088b7ad 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -205,6 +205,44 @@ struct ddebug_class_param {
const struct ddebug_class_map *map;
};
+/**
+ * DYNDBG_CLASSMAP_PARAM - control a ddebug-classmap from a sys-param
+ * @_name: sysfs node name
+ * @_var: name of the classmap var defining the controlled classes/bits
+ * @_flags: flags to be toggled, typically just 'p'
+ *
+ * Creates a sysfs-param to control the classes defined by the
+ * exported classmap, with bits 0..N-1 mapped to the classes named.
+ * This version keeps class-state in a private long int.
+ */
+#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 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 (exported) classmap var defining the classes/bits
+ * @_flags: flags to be toggled, typically just 'p'
+ *
+ * Creates a sysfs-param to control the classes defined by the
+ * exported clasmap, with bits 0..N-1 mapped to the classes named.
+ * This version keeps class-state in user @_bits. This lets drm check
+ * __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, ¶m_ops_dyndbg_classes, \
+ &_name##_##_flags, 0600)
+
/*
* pr_debug() and friends are globally enabled or modules have selectively
* enabled them.
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 781781835094..9283f2866415 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -660,6 +660,30 @@ 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)
@@ -678,26 +702,15 @@ 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));
@@ -1163,15 +1176,24 @@ static const struct proc_ops proc_fops = {
static void ddebug_sync_classbits(const struct kernel_param *kp, const char *modname)
{
const struct ddebug_class_param *dcp = kp->arg;
+ unsigned long new_bits;
- /* 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);
+ 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,
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 5cfc156ca4bb..32a9d49a7a3b 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * Kernel module for testing dynamic_debug
+ * Kernel module to test/demonstrate dynamic_debug features,
+ * particularly classmaps and their support for subsystems like DRM.
*
* Authors:
* Jim Cromie <jim.cromie@xxxxxxxxx>
@@ -43,36 +44,21 @@ module_param_cb(do_prints, ¶m_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, ¶m_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.
+ * Demonstrate/test both types of classmaps, each 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.
+ * Pair the 6 parts by type, to show the pattern of repetition and
+ * change within each.
*
- * 1st, dyndbg expects a client-provided enum-type as source of
- * category/classid truth. DRM has DRM_UT_<CORE,DRIVER,KMS,etc>.
+ * 1st, dyndbg classmaps follows drm.debug convention, and expects a
+ * client-provided enum-type as source of category/classid truth. DRM
+ * gives 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
+ * Declare the 2 enums now.
*/
/* numeric input, independent bits */
@@ -91,12 +77,15 @@ enum cat_disjoint_bits {
/* numeric verbosity, V2 > V1 related */
enum cat_level_num { V0 = 16, V1, V2, V3, V4, V5, V6, V7 };
-/* recapitulate DRM's parent(drm.ko) <-- _submod(drivers,helpers) */
+/*
+ * use/demonstrate multi-module-group classmaps, as for DRM
+ */
#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.
+ * For module-groups of 1+, define classmaps with names (stringified
+ * enum-symbols) copied from above. 1-to-1 mapping is recommended.
+ * The classmap is exported, so that other modules in the group can
+ * link to it and control their prdbgs.
*/
DYNDBG_CLASSMAP_DEFINE(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS,
@@ -116,11 +105,12 @@ 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
+ * for use-cases that want it, provide a sysfs-param to set the
+ * classes in the classmap. It is at this interface where the
+ * "v3>v2" property is applied to DD_CLASS_TYPE_LEVEL_NUM inputs.
*/
-
-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);
#ifdef FORCE_CLASSID_CONFLICT_MODPROBE
/*
@@ -131,12 +121,10 @@ DYNDBG_CLASSMAP_DEFINE(classid_range_conflict, 0, D2_CORE + 1, "D3_CORE");
#endif
#else /* TEST_DYNAMIC_DEBUG_SUBMOD */
-
/*
- * in submod/drm-drivers, use the classmaps defined in top/parent
- * module above.
+ * the +1 members of a multi-module group refer to the classmap
+ * DEFINEd (and exported) above.
*/
-
DYNDBG_CLASSMAP_USE(map_disjoint_bits);
DYNDBG_CLASSMAP_USE(map_level_num);
@@ -211,6 +199,7 @@ static void __exit test_dynamic_debug_exit(void)
module_init(test_dynamic_debug_init);
module_exit(test_dynamic_debug_exit);
+MODULE_DESCRIPTION("test/demonstrate dynamic-debug features");
MODULE_AUTHOR("Jim Cromie <jim.cromie@xxxxxxxxx>");
MODULE_DESCRIPTION("Kernel module for testing dynamic_debug");
MODULE_LICENSE("GPL");
diff --git a/lib/test_dynamic_debug_submod.c b/lib/test_dynamic_debug_submod.c
index 9a893402ce1a..0d15f3ffe466 100644
--- a/lib/test_dynamic_debug_submod.c
+++ b/lib/test_dynamic_debug_submod.c
@@ -1,6 +1,9 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * Kernel module for testing dynamic_debug
+ * Kernel module to test/demonstrate dynamic_debug features,
+ * particularly classmaps and their support for subsystems, like DRM,
+ * which defines its drm_debug classmap in drm module, and uses it in
+ * helpers & drivers.
*
* Authors:
* Jim Cromie <jim.cromie@xxxxxxxxx>
@@ -8,3 +11,7 @@
#define TEST_DYNAMIC_DEBUG_SUBMOD
#include "test_dynamic_debug.c"
+
+MODULE_DESCRIPTION("test/demonstrate dynamic-debug subsystem support");
+MODULE_AUTHOR("Jim Cromie <jim.cromie@xxxxxxxxx>");
+MODULE_LICENSE("GPL");
--
2.48.1
