Thread (67 messages) 67 messages, 2 authors, 2025-09-08

Re: [PATCH v4 16/58] dyndbg-API: remove DD_CLASS_TYPE_(DISJOINT|LEVEL)_NAMES and code

From: Louis Chauvet <louis.chauvet@bootlin.com>
Date: 2025-09-05 21:16:19
Also in: amd-gfx, dri-devel, intel-gfx, linux-arm-msm, lkml


Le 03/08/2025 à 05:57, Jim Cromie a écrit :
Remove the DD_CLASS_TYPE_*_NAMES classmap types and code.

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 reduce LOC & test-surface; simplify things.

Also rename enum class_map_type to enum ddebug_class_map_type.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
quoted hunk ↗ jump to hunk
---
  include/linux/dynamic_debug.h |  23 ++------
  lib/dynamic_debug.c           | 102 +++-------------------------------
  lib/test_dynamic_debug.c      |  26 ---------
  3 files changed, 14 insertions(+), 137 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index f4d1d08cd5a7c..769f02456c8e0 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -58,27 +58,16 @@ 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, 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
  	 */
  };
  
@@ -88,7 +77,7 @@ struct _ddebug_class_map {
  	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;
  };
  
  /**
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 09f19155d7f02..2cd28a64578dd 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -646,76 +646,6 @@ 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_and_replace(instr, '\n', '\0', GFP_KERNEL);
-	if (!tmp)
-		return -ENOMEM;
-
-	/* 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 *mod_name)
@@ -724,29 +654,17 @@ 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 */
@@ -812,12 +730,8 @@ 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 8434f70b51bb3..9c3e53cd26bd8 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -74,13 +74,6 @@ DECLARE_DYNDBG_CLASSMAP(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS, 0,
  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,
@@ -88,13 +81,6 @@ DECLARE_DYNDBG_CLASSMAP(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, 14,
  DD_SYS_WRAP(level_num, p);
  DD_SYS_WRAP(level_num, T);
  
-/* 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);
-
  /* stand-in for all pr_debug etc */
  #define prdbg(SYM) __pr_debug_cls(SYM, #SYM " msg\n")
  
@@ -102,10 +88,6 @@ 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 +111,6 @@ 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)
-- 
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

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