1 files changed, 41 insertions, 16 deletions

diff --git a/drivers/s390/char/sclp_cpi_sys.c b/drivers/s390/char/sclp_cpi_sys.c
index 9f37456222e9..d887bd261d28 100644
--- a/drivers/s390/char/sclp_cpi_sys.c
+++ b/drivers/s390/char/sclp_cpi_sys.c
@@ -27,6 +27,8 @@
 #define CPI_LENGTH_NAME 8
 #define CPI_LENGTH_LEVEL 16
 
+static DEFINE_MUTEX(sclp_cpi_mutex);
+
 struct cpi_evbuf {
 	struct evbuf_header header;
 	u8	id_format;
@@ -124,21 +126,15 @@ static int cpi_req(void)
 	int response;
 
 	rc = sclp_register(&sclp_cpi_event);
-	if (rc) {
-		printk(KERN_WARNING "cpi: could not register "
-			"to hardware console.\n");
+	if (rc)
 		goto out;
-	}
 	if (!(sclp_cpi_event.sclp_receive_mask & EVTYP_CTLPROGIDENT_MASK)) {
-		printk(KERN_WARNING "cpi: no control program "
-			"identification support\n");
 		rc = -EOPNOTSUPP;
 		goto out_unregister;
 	}
 
 	req = cpi_prepare_req();
 	if (IS_ERR(req)) {
-		printk(KERN_WARNING "cpi: could not allocate request\n");
 		rc = PTR_ERR(req);
 		goto out_unregister;
 	}
@@ -148,10 +144,8 @@ static int cpi_req(void)
 
 	/* Add request to sclp queue */
 	rc = sclp_add_request(req);
-	if (rc) {
-		printk(KERN_WARNING "cpi: could not start request\n");
+	if (rc)
 		goto out_free_req;
-	}
 
 	wait_for_completion(&completion);
 
@@ -223,7 +217,12 @@ static void set_string(char *attr, const char *value)
 static ssize_t system_name_show(struct kobject *kobj,
 				struct kobj_attribute *attr, char *page)
 {
-	return snprintf(page, PAGE_SIZE, "%s\n", system_name);
+	int rc;
+
+	mutex_lock(&sclp_cpi_mutex);
+	rc = snprintf(page, PAGE_SIZE, "%s\n", system_name);
+	mutex_unlock(&sclp_cpi_mutex);
+	return rc;
 }
 
 static ssize_t system_name_store(struct kobject *kobj,
@@ -237,7 +236,9 @@ static ssize_t system_name_store(struct kobject *kobj,
 	if (rc)
 		return rc;
 
+	mutex_lock(&sclp_cpi_mutex);
 	set_string(system_name, buf);
+	mutex_unlock(&sclp_cpi_mutex);
 
 	return len;
 }
@@ -248,7 +249,12 @@ static struct kobj_attribute system_name_attr =
 static ssize_t sysplex_name_show(struct kobject *kobj,
 				 struct kobj_attribute *attr, char *page)
 {
-	return snprintf(page, PAGE_SIZE, "%s\n", sysplex_name);
+	int rc;
+
+	mutex_lock(&sclp_cpi_mutex);
+	rc = snprintf(page, PAGE_SIZE, "%s\n", sysplex_name);
+	mutex_unlock(&sclp_cpi_mutex);
+	return rc;
 }
 
 static ssize_t sysplex_name_store(struct kobject *kobj,
@@ -262,7 +268,9 @@ static ssize_t sysplex_name_store(struct kobject *kobj,
 	if (rc)
 		return rc;
 
+	mutex_lock(&sclp_cpi_mutex);
 	set_string(sysplex_name, buf);
+	mutex_unlock(&sclp_cpi_mutex);
 
 	return len;
 }
@@ -273,7 +281,12 @@ static struct kobj_attribute sysplex_name_attr =
 static ssize_t system_type_show(struct kobject *kobj,
 				struct kobj_attribute *attr, char *page)
 {
-	return snprintf(page, PAGE_SIZE, "%s\n", system_type);
+	int rc;
+
+	mutex_lock(&sclp_cpi_mutex);
+	rc = snprintf(page, PAGE_SIZE, "%s\n", system_type);
+	mutex_unlock(&sclp_cpi_mutex);
+	return rc;
 }
 
 static ssize_t system_type_store(struct kobject *kobj,
@@ -287,7 +300,9 @@ static ssize_t system_type_store(struct kobject *kobj,
 	if (rc)
 		return rc;
 
+	mutex_lock(&sclp_cpi_mutex);
 	set_string(system_type, buf);
+	mutex_unlock(&sclp_cpi_mutex);
 
 	return len;
 }
@@ -298,8 +313,11 @@ static struct kobj_attribute system_type_attr =
 static ssize_t system_level_show(struct kobject *kobj,
 				 struct kobj_attribute *attr, char *page)
 {
-	unsigned long long level = system_level;
+	unsigned long long level;
 
+	mutex_lock(&sclp_cpi_mutex);
+	level = system_level;
+	mutex_unlock(&sclp_cpi_mutex);
 	return snprintf(page, PAGE_SIZE, "%#018llx\n", level);
 }
 
@@ -320,8 +338,9 @@ static ssize_t system_level_store(struct kobject *kobj,
 	if (*endp)
 		return -EINVAL;
 
+	mutex_lock(&sclp_cpi_mutex);
 	system_level = level;
-
+	mutex_unlock(&sclp_cpi_mutex);
 	return len;
 }
 
@@ -334,7 +353,9 @@ static ssize_t set_store(struct kobject *kobj,
 {
 	int rc;
 
+	mutex_lock(&sclp_cpi_mutex);
 	rc = cpi_req();
+	mutex_unlock(&sclp_cpi_mutex);
 	if (rc)
 		return rc;
 
@@ -373,12 +394,16 @@ int sclp_cpi_set_data(const char *system, const char *sysplex, const char *type,
 	if (rc)
 		return rc;
 
+	mutex_lock(&sclp_cpi_mutex);
 	set_string(system_name, system);
 	set_string(sysplex_name, sysplex);
 	set_string(system_type, type);
 	system_level = level;
 
-	return cpi_req();
+	rc = cpi_req();
+	mutex_unlock(&sclp_cpi_mutex);
+
+	return rc;
 }
 EXPORT_SYMBOL(sclp_cpi_set_data);