wifi: iwlwifi: dbg-tlv: avoid extra allocation/copy

In iwl_dbg_tlv_alloc_trigger() the code makes a copy just
to modify it and pass it to another function to make a copy
again. Change the API to return the copy so the adjustment
can be done without another copy.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Gregory Greenman <gregory.greenman@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240128084842.075c8b9f7030.Id5a61e1a87a9c6932727fb4e2c9b54ed6070362a@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c

@@ -64,7 +64,8 @@ dbg_ver_table[IWL_DBG_TLV_TYPE_NUM] = {
 	[IWL_DBG_TLV_TYPE_CONF_SET]	= {.min_ver = 1, .max_ver = 1,},
 };
 
-static int iwl_dbg_tlv_add(const struct iwl_ucode_tlv *tlv,
+/* add a new TLV node, returning it so it can be modified */
+static struct iwl_ucode_tlv *iwl_dbg_tlv_add(const struct iwl_ucode_tlv *tlv,
 					     struct list_head *list)
 {
 	u32 len = le32_to_cpu(tlv->length);
@@ -72,13 +73,13 @@ static int iwl_dbg_tlv_add(const struct iwl_ucode_tlv *tlv,
 
 	node = kzalloc(sizeof(*node) + len, GFP_KERNEL);
 	if (!node)
-		return -ENOMEM;
+		return NULL;
 
 	memcpy(&node->tlv, tlv, sizeof(node->tlv));
 	memcpy(node->tlv.data, tlv->data, len);
 	list_add_tail(&node->list, list);
 
-	return 0;
+	return &node->tlv;
 }
 
 static bool iwl_dbg_tlv_ver_support(const struct iwl_ucode_tlv *tlv)
@@ -106,7 +107,9 @@ static int iwl_dbg_tlv_alloc_debug_info(struct iwl_trans *trans,
 	IWL_DEBUG_FW(trans, "WRT: Loading debug cfg: %s\n",
 		     debug_info->debug_cfg_name);
 
-	return iwl_dbg_tlv_add(tlv, &trans->dbg.debug_info_tlv_list);
+	if (!iwl_dbg_tlv_add(tlv, &trans->dbg.debug_info_tlv_list))
+		return -ENOMEM;
+	return 0;
 }
 
 static int iwl_dbg_tlv_alloc_buf_alloc(struct iwl_trans *trans,
@@ -175,7 +178,9 @@ static int iwl_dbg_tlv_alloc_hcmd(struct iwl_trans *trans,
 		return -EINVAL;
 	}
 
-	return iwl_dbg_tlv_add(tlv, &trans->dbg.time_point[tp].hcmd_list);
+	if (!iwl_dbg_tlv_add(tlv, &trans->dbg.time_point[tp].hcmd_list))
+		return -ENOMEM;
+	return 0;
 }
 
 static int iwl_dbg_tlv_alloc_region(struct iwl_trans *trans,
@@ -246,11 +251,9 @@ static int iwl_dbg_tlv_alloc_trigger(struct iwl_trans *trans,
 				     const struct iwl_ucode_tlv *tlv)
 {
 	const struct iwl_fw_ini_trigger_tlv *trig = (const void *)tlv->data;
-	struct iwl_fw_ini_trigger_tlv *dup_trig;
 	u32 tp = le32_to_cpu(trig->time_point);
 	u32 rf = le32_to_cpu(trig->reset_fw);
-	struct iwl_ucode_tlv *dup = NULL;
-	int ret;
+	struct iwl_ucode_tlv *new_tlv;
 
 	if (le32_to_cpu(tlv->length) < sizeof(*trig))
 		return -EINVAL;
@@ -267,20 +270,18 @@ static int iwl_dbg_tlv_alloc_trigger(struct iwl_trans *trans,
 		     "WRT: time point %u for trigger TLV with reset_fw %u\n",
 		     tp, rf);
 	trans->dbg.last_tp_resetfw = 0xFF;
-	if (!le32_to_cpu(trig->occurrences)) {
-		dup = kmemdup(tlv, sizeof(*tlv) + le32_to_cpu(tlv->length),
-				GFP_KERNEL);
-		if (!dup)
+
+	new_tlv = iwl_dbg_tlv_add(tlv, &trans->dbg.time_point[tp].trig_list);
+	if (!new_tlv)
 		return -ENOMEM;
-		dup_trig = (void *)dup->data;
-		dup_trig->occurrences = cpu_to_le32(-1);
-		tlv = dup;
-	}
 
-	ret = iwl_dbg_tlv_add(tlv, &trans->dbg.time_point[tp].trig_list);
-	kfree(dup);
+	if (!le32_to_cpu(trig->occurrences)) {
+		struct iwl_fw_ini_trigger_tlv *new_trig = (void *)new_tlv->data;
 
-	return ret;
+		new_trig->occurrences = cpu_to_le32(-1);
+	}
+
+	return 0;
 }
 
 static int iwl_dbg_tlv_config_set(struct iwl_trans *trans,
@@ -304,7 +305,9 @@ static int iwl_dbg_tlv_config_set(struct iwl_trans *trans,
 		return -EINVAL;
 	}
 
-	return iwl_dbg_tlv_add(tlv, &trans->dbg.time_point[tp].config_list);
+	if (!iwl_dbg_tlv_add(tlv, &trans->dbg.time_point[tp].config_list))
+		return -ENOMEM;
+	return 0;
 }
 
 static int (*dbg_tlv_alloc[])(struct iwl_trans *trans,
@@ -1148,7 +1151,9 @@ iwl_dbg_tlv_add_active_trigger(struct iwl_fw_runtime *fwrt,
 	if (!match) {
 		IWL_DEBUG_FW(fwrt, "WRT: Enabling trigger (time point %u)\n",
 			     le32_to_cpu(trig->time_point));
-		return iwl_dbg_tlv_add(trig_tlv, trig_list);
+		if (!iwl_dbg_tlv_add(trig_tlv, trig_list))
+			return -ENOMEM;
+		return 0;
 	}
 
 	return iwl_dbg_tlv_override_trig_node(fwrt, trig_tlv, match);