Merge pull request #1646 from mmichal10/configure-preempt

configure: add preemption_model_*() functions

configure.d/1_preempt_model.conf

@@ -0,0 +1,52 @@
+#!/bin/bash
+#
+# Copyright(c) 2025 Huawei Technologies
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+. $(dirname $3)/conf_framework.sh
+
+check() {
+	cur_name=$(basename $2)
+	config_file_path=$1
+	if compile_module $cur_name "preempt_model_voluntary();" "linux/preempt.h" &&
+	   compile_module $cur_name "preempt_model_none();" "linux/preempt.h"
+	then
+		echo $cur_name "1" >> $config_file_path
+	else
+		echo $cur_name "2" >> $config_file_path
+	fi
+}
+
+apply() {
+    case "$1" in
+    "1")
+		add_function "
+	static inline int cas_preempt_model_voluntary(void)
+	{
+		return preempt_model_voluntary();
+	}"
+		add_function "
+	static inline int cas_preempt_model_none(void)
+	{
+		return preempt_model_none();
+	}" ;;
+
+    "2")
+		add_function "
+	static inline int cas_preempt_model_voluntary(void)
+	{
+		return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY);
+	}"
+		add_function "
+	static inline int cas_preempt_model_none(void)
+	{
+		return IS_ENABLED(CONFIG_PREEMPT_NONE);
+	}" ;;
+
+    *)
+        exit 1
+    esac
+}
+
+conf_run $@

modules/cas_cache/main.c

@@ -65,9 +65,6 @@ static inline uint32_t involuntary_preemption_enabled(void)
 	}
 
 #ifdef CONFIG_PREEMPT_DYNAMIC
-	/* preempt_model_none() or preempt_model_voluntary() are not defined if
-	 * the kernel has been compiled without PREEMPT_DYNAMIC
-	 */
 	printk(KERN_WARNING OCF_PREFIX_SHORT
 		"The kernel has been compiled with preemption configurable\n"
 		"at boot time (PREEMPT_DYNAMIC=y). Open CAS doesn't support\n"
@@ -75,7 +72,7 @@ static inline uint32_t involuntary_preemption_enabled(void)
 		"\"preempt=\" to \"none\" or \"voluntary\" in the kernel"
 		" command line\n");
 
-	if (!preempt_model_none() && !preempt_model_voluntary()) {
+	if (!cas_preempt_model_none() && !cas_preempt_model_voluntary()) {
 		printk(KERN_ERR OCF_PREFIX_SHORT
 			"The kernel has been booted with involuntary "
 			"preemption enabled.\nFailed to load Open CAS kernel "